Stem Cells in Gene Therapy/Gene Editing PDF

12/4/2024 Stem Cells in Gene Therapy/Gene Editing 1 What is Cell/Gene Therapy ▪ A branch of Regenerative Medicine, an emerging field that involves the "process of replacing, engineering or regenerating human cells, tissues or organs to restore or estab...

12/4/2024 Stem Cells in Gene Therapy/Gene Editing 1 What is Cell/Gene Therapy ▪ A branch of Regenerative Medicine, an emerging field that involves the "process of replacing, engineering or regenerating human cells, tissues or organs to restore or establish normal function”. ▪ Gene therapy is the the delivery of therapeutic gene into a patient's cells to treat disease. ▪ Cell therapy is the delivery of intact, living cells into a patient to treat disease. ▪ Combination Cell/Gene Therapy approaches that seek to insert genes into a patients’ own cells to control the diseases are in clinical trials now. 2 1  12/4/2024 Gene Therapy ❑ Gene therapy is an experimental technique that uses genes to treat or prevent disease. ❑ In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery. Researchers are testing several approaches to gene therapy, including: Replacing a mutated gene that causes disease with a healthy copy of the gene. Inactivating, or “knocking out,” a mutated gene that is functioning improperly. Introducing a new gene into the body to help fight a disease. 3 Gene therapy ❑ Although gene therapy is a promising treatment option for a number of diseases (including inherited disorders, some types of cancer, and certain viral infections), the technique remains risky and is still under study to make sure that it will be safe and effective. ❑ Gene therapy is currently being tested only for diseases that have no other cures. 4 2  12/4/2024 Different Routes of Gene Therapy Two ways to deliver genes: 1. Ex vivo approach 2. In vivo approach ▪ 1. Ex vivo approach: Target cells are removed from the body and grown in vitro. The gene is then introduced into the cultured cells. These cells are then re-introduced into the same individual Examples: Fibroblast cells, Hematopoietic cells, Stem Cells 5 Dr.Padmesh. V ▪ 2. In vivo approach (Direct Gene Transfer): Cloned therapeutic gene is introduced directly into the affected tissue, without removing cells from the body. Specially designed vehicles are needed. Examples: Lungs, Brain 6 3  12/4/2024 Ex vivo gene therapy – – Usually with blood cells (lymphocytes or hematopoietic stem cells) for diseases affecting the hematopoietic system In vivo gene therapy – – Oncolytic adenoviruses for the treatment of cancer – Adeno-associated vectors for the treatment of Duchenne muscular dystrophy or hemophilia – Non-viral vectors (Not oncogenic) 7 Ex Vivo and In Vivo Gene Therapies 8 4  12/4/2024 Ex Vivo Gene Therapy: Putting Functional Genes Into Marrow Stem Cells Patient 9 Ex Vivo Gene Therapy: Putting Functional Genes Into Marrow Stem Cells Mobilization Leukapheresis OR Bone Marrow Harvest Patient 10 5  12/4/2024 Ex Vivo Gene Therapy: Putting Functional Genes Into Marrow Stem Cells Virus-Mediated Transfer of Therapeutic Gene GOAL: Gene modified cells engraft and correct or treat the disease - Cancer - Genetic disease - Infectious disease Patient 11 Ex Vivo Gene Therapy: Putting Functional Genes Into Marrow Stem Cells or T cells Outside of the Body Reinfusion Patient 12 6  12/4/2024 METHODS OF GENE DELIVERY: Parenteral injection 1.PHYSICAL METHODS: Parenteral injection Microinjection Aerosol Gene gun 2.CHEMICAL METHODS: Calcium phosphate DEAE-Dextran Liposomes 3.BIOLOGICAL METHODS: Viral Vectors like - Retrovirus - Adenovirus - HSV 13 Aerosol Gene Delivery Reference: 2015 Jun;12(6):977-91. doi: 10.1517/17425247.2015.986454 Aerosol gene delivery using viral vectors and cationic carriers for in vivo lung cancer therapy 14 7  12/4/2024 Dr.Padmesh.V Common Vectors Used For Gene Therapy: ▪ 1.Retroviruses ▪ 2. Adenoviruses ▪ 3.Liposomes Video: Viral Vectors-Overview 15 Dr.Padmesh.V 1. Retroviruses: ▪ Retroviruses used in gene therapy are made incapable of independent replication, to prevent sideeffects associatedwith infectivity. ▪ RetrovirusesareusedONLYin EXVIVO THERAPY. ▪ Advantages: ▪ Chromosomalintegration & stable modification of target cells. ▪ Disadvantages: ▪ Uncontrolled integration; May be oncogenic. ▪ Can not infect non-dividing cells. 16 8  12/4/2024 Dr.Padmesh.V ▪ 2. ADENO VIRUSES: ▪ Second most commonly used delivery system in gene therapy. ▪ Adenoviruses can be produced at high titres in cultures. ▪ Advantages: ▪ Can infect non-dividing cells, thus suitable for gene therapy of Cystic fibrosis, DMD. ▪ Non-integration to chromosome. ▪ Avoids the risks of uncontrolled integration. ▪ Efficient genetransfer. ▪ Disadvantages: ▪ Transient expression of gene due to episomal integration. ▪ Provokes immune response. 17 Dr.Padmesh.V ▪ 3. LIPOSOMES: ▪ Theseare lipid bilayers surroundinganaqueousvesicle. ▪ Canbe usedto introduce foreign DNA into atarget cell. ▪ Advantages: ▪ Saferwhen comparedtoViral vectors. ▪ Can carry large DNA molecules. ▪ Disadvantages: ▪ Inefficient transfer. ▪ Transient expression. 18 9  12/4/2024 Dr.Padmesh.V Liposomes 19 1. SOMATIC CELL THERAPY: ▪ Insertion of therapeutic gene into somatic cells like fibroblasts, myoblasts, epithelial cells, nervous cells, glial cells etc. ▪ This can correct the genetic defect in the patient ▪ However, in somatic cell therapy, transgene cannot be passed on to the next generation orsiblings etc. 20 10  12/4/2024 2. GERM LINE THERAPY: ▪ Introduction of the foreign gene into germ cells like sperm / ovum / fertilized egg (Totipotent Stem Cell). ▪ Results in expression of modified features in both somatic as well as germ cells of the offspring. ▪ Considered unethical, and had not beenadvocated in humans until 2018. 21 ▪1.SOMATIC CELL THERAPY: History of gene therapy The 1980s… The first attempt to use gene therapy to treat live humans in clinical trials began in the late 1980s. These trials weren’t reported until the beginning of the 1990’s. 22 11  12/4/2024 The 1990s… ▪ In this 1990 report from National Cancer Institute (NCI) in USA, scientists removed white blood cells from patients with advanced melanoma. ▪ In the laboratory, researchers modified the genetics of the white blood cells. ▪ A retrovirus was employed to insert a gene called interleukin-2. ▪ Finally, these genetically altered cells were infused back into the live patients. ▪ The report demonstrated that gene therapy could be delivered live humans 23 The 1990s… a longer-term clinical trial to treat children with ADA- SCID disease Immune System disease SCID stands for severe combined immuno-deficiency. The ADA refers to the fact that a specific gene, adenosine deaminase (ADA) is missing from these patients. A retrovirus was used to transfer the ADA gene into isolated T-cells. These gene-modified T cells were then infused back into the young patients. To everyone’s delight, a significant improvement in the health of the children was observed. 24 12  12/4/2024 + Immune system was partially restored by the therapy. Production of the missing enzyme was temporarily stimulated, but the new cells with functional genes were not generated. The effects were successful, but temporary. 25 26 13  12/4/2024 In vivo gene therapy ( injected into hepatic artery) Ornithine transcarbamylase deficiency (OTCD) is an inherited disorder that causes ammonia to accumulate in the blood. Ammonia, which is formed when proteins are broken down in the body, is toxic if the levels become too high. The nervous system is especially sensitive to the effects of excess ammonia. 27 In 2003, the FDA halted all gene therapy trials using retroviral vectors in blood stem cells Study had treated «bubble baby syndrome». X-linked severe combined immunodefficiency disease Several patients developed leukemia-like coditions 28 14  12/4/2024 Gene Therapy in Blood Cells (Hematopoietic Stem Cells) 29 Gene Therapy in Blood Cells (Hematopoietic Stem Cells) 30 15  12/4/2024 Gene Therapy in Blood Cells (Hematopoietic Stem Cells) Therapeutic gene 31 Gene Therapy in Blood Cells (Hematopoietic Stem Cells) 32 16  12/4/2024 Gene Therapy in Blood Cells (Hematopoietic Stem Cells) 33 Gene Therapy in Blood Cells (Hematopoietic Stem Cells) Today, Similar Therapeutic gene strategy can be used (Against HIV for example) for the treatment of the other diseases such HIV 34 17  12/4/2024 Some targets for gene therapy CD4 and a coreceptor (either CCR5 or CXCR4) 35 36 18  12/4/2024 2016, Strimvelis, a stem cell gene therapy to treat ADA-SCID patients. $665,000, (EMA) form of pancreas disease is caused by the absence of a gene called lipoprotein lipase Glybera $1 million dollars Blood diseases such as sickle-cell disease and beta-thalassemia, Cancer Blindness such as Leber congenital amaurosis (mutation in the CEP290 gene that leads to a nonfunctional protein. When the protein doesn’t work, rod cells in the retina die and light-gathering photoreceptors can’t renew themselves, resulting in blindness). Additional gene therapy trials are currently underway for: HIV (helper T-cells engineered with a CCR5 gene knock-out) Choroideremia (AAV virus used to insert REP1 gene) Sickle cell anemia (modified umbilical stem cell cord blood) ADA-SCID (‘bubble-children’ treated with modified stem cells to restore the ADA gene) 37 In 2018 FDA approval for their Luxturna therapy. AAV vector to deliver a gene (RPE65) into the eye tissue of patients suffering from a rare disease called RPE65 mutation-associated retinal dystropy. Sidenote: This Luxturna therapy is regarded as the first true gene therapy, because the viral treatment is delivered directly to the patient’s body. Previous gene therapy approvals (Yescarta and Kymriah) are called ex vivo treatments, as the cells receiving gene therapy (immune cells) are removed from the body prior to treatment. $850K price-tag for both eyes. 38 19  12/4/2024 Gene Therapies Pursued In 2019 39 ¹ This table lists gene therapies in significant stages of the clinical pipeline. Many are in Phase 3, approved or else have demonstrated efficacy in Ph1/2 trials. I’ve included therapies for diseases in which the endogenous gene is missing or mutated and then introduced with a vector (i.e. virus). Other gene therapies (not listed) work by supplying chimeric genes or genes that aren’t naturally produced in the target cell (CAR-T, cancer vaccines, etc.) * These trials rely on viral vectors to deliver genome editing technology (i.e. ZFN, CRISPR). 40 20  12/4/2024 FDA Approved Cellular and Gene Therapy Products Approved Products ALLOCORD (HPC, Cord Blood) SSM Cardinal Glennon Children's Medical Center CLEVECORD (HPC Cord Blood) Cleveland Cord Blood Center Ducord, HPC Cord Blood Duke University School of Medicine GINTUIT (Allogeneic Cultured Keratinocytes and Fibroblasts in Bovine Collagen) Organogenesis Incorporated HEMACORD (HPC, cord blood) New York Blood Center HPC, Cord Blood Clinimmune Labs, University of Colorado Cord Blood Bank HPC, Cord Blood - MD Anderson Cord Blood Bank MD Anderson Cord Blood Bank HPC, Cord Blood - LifeSouth LifeSouth Community Blood Centers, Inc. HPC, Cord Blood - Bloodworks Bloodworks IMLYGIC (talimogene laherparepvec) BioVex, Inc., a subsidiary of Amgen Inc. KYMRIAH (tisagenlecleucel) Novartis Pharmaceuticals Corporation LAVIV (Azficel-T) Fibrocall Technologies LUXTURNA Spark Therapeutics, Inc. MACI (Autologous Cultured Chondrocytes on a Porcine Collagen Membrane) Vericel Corp. PROVENGE (sipuleucel-T) Dendreon Corp. TECARTUS (brexucabtagene autoleucel) Kite Pharma, Inc. YESCARTA (axicabtagene ciloleucel) Kite Pharma, Incorporated ZOLGENSMA (onasemnogene abeparvovec-xioi) AveXis, Inc. https://www.fda.gov/vaccines-blood-biologics/cellular-gene-therapy-products/approved-cellular-and-gene-therapy-products 41 ▪2. GERMLINE THERAPY: Gene Editing What is CRISPR? (Clustered regularly interspaced short palindromic repeats) A genome editing technique that: Targets a specific section of DNA Makes a precise cut/break at the target site Can do one of two things: Makes a gene nonfunctional Replace one version of a gene with another 42 21  12/4/2024 CRISPR 43 DNA template with desired sequence Cas9 nuclease with guide RNA DNA base to be changed DNA edited to desired sequence Mechanism of CRISPR gene editing system Video: CRISPR- Gene editing and beyond 44 22  12/4/2024 What are the potential applications of CRISPR to human health? ✓ Basic research tool for use in human cells or embryos to help understand normal development, model human disease and develop new treatments ✓ For gene editing in somatic cells, either ex vivo or in vivo, to treat or prevent disease. ✓ For gene editing in gametes or embryos. With the aim of correcting disease-causing mutations in the next Generation – so-called germline gene editing. 45 What is the path forward? Safety – ethics – informed consent – human and ecological health December 2015: International Summit on Human Gene Editing (Washington, DC) Bjoertvedt, CC BY-SA 3.0 To consider the scientific, ethical and societal issues raised by human genome editing. National Academy of Sciences, CC BY-NC-SA 2.0 46 23  12/4/2024 The Major Recommendations Of The Committee (February 2017) Major recommendations of the National Academy of Sciences report on human genome editing. The committee did not recommend an outright ban on human germline editing but set out guidelines around when to (1) proceed under existing regulatory processes (green), (2) proceed with caution under stringent oversight and public input (orange) or (3) not proceed at this time (red). 47 Extension of human gene editing, either somatic or germline, beyond the treatment or prevention of serious disease, to genetic enhancement strategies was specifically banned. ‘Healthy babies not designer babies’ was the call. 48 24  12/4/2024 Gene Editing And Human Development Creation of human embryos specifically for research purposes is banned, restricting gene-editing approaches to potentially less viable, discarded early embryos from IVF programs. Also, in many jurisdictions, gene editing to generate potentially heritable genetic changes is forbidden. In many countries, any attempt at gene editing in the early human embryo, even if the embryos were only studied in culture, were banned. 49 50 25  12/4/2024 51 Ethical Aspects of Genome Editing CRISPR, and other genome-editing tools like it, provide a faster, cheaper and more reliable way of editing DNA for a wide range of potential applications. Among the most controversial would be using CRISPR to gene-edit human embryos. The near-term consequence of this kind of research could be "sick babies, disabled babies, dead babies" It appears that the disease can still occur if only certain cells were altered. It could dampen other types of research into using CRISPR for non- reproductive uses. 52 26  12/4/2024 Ethical Aspects of Genome Editing The reason why CRISPR creates more ethical debates than previous gene editing techniques is that it can be applied in any molecular biology laboratory as it can be applied easily and quickly. This makes it easier to control when facilitating the abuse of such a serious application. 53 Balance of Risks and Benefits One of the most important ethical points in research is that benefits should be significantly greater than risks. Risks are unknown as they can harm the environment and living things. CRISPR-Cas9 application can produce off-target mutations which can cause enormous damage. The highest off-target (frequency) effect was seen in human cells. The problem is that large genomes contain identical or substantially identical homologous regions. CRISPR-Cas9 can target these similar regions instead of the region that needs to be cut. Targeting these undesirable sites may create mutations that will lead to cell death or transformation. Further improvement is needed to reduce the risk of mutation, especially in treatment interventions. 54 27  12/4/2024 Ecological Imbalance The gene regulated by CRISPR-Cas9 is continuously transferred to the next generations as the dominant gene. If a non-target gene has been introduced, the mutations will continue to be out-of-target and transferred to subsequent generations, as this gene will continue to be manifested in generations of living creatures. Therefore, it is difficult to control the distribution of this gene in the population; the entire population of the gene may disappear and there may be serious problems in the ecosystem balance. 55 Another major ethical issue is the fact that CRISPR can be used outside of therapeutic arrangements in the future. CRISPR will facilitate the intervention of somatic cells through germ cells and produce babies in order. Many phenotypic features, apart from environmental conditions, have a genetic component that can be interfered. For example, this technique can be used to increase the performance of athletes or to prevent the tendency of violence to suppress addiction. From this point of view, although gene therapy seems to give positive results, it will create an unfair system. 56 28  12/4/2024 In Conclusion ❑ Although gene therapy is a promising treatment option for a number of diseases (including inherited disorders, some types of cancer, and certain viral infections), the technique remains risky and is still under study to make sure that it will be safe and effective. ❑ Gene therapy is currently being tested only for diseases that have no other cures. 57 As the Nobel laureate physicist Richard Feynman says, «science gives us the key that opens the door to heaven, but the same key opens the door to hell» 58 29  12/4/2024 You can reach more information about CHRISPR and genome editing https://www.risingtidebio.com/what-is-gene-therapy-uses/#recent https://www.genome.gov/about-genomics/policy-issues/Genome-Editing/ethical-concerns https://www.geneticsandsociety.org/internal-content/human-gene-editing-frequently-asked-questions How CRISPR could change the world—And why that frightens many of us https://geneticliteracyproject.org/2016/10/04/crispr-change- world-frightens-many-us/ What can you achieve with CRISPR therapy today? http://medicalfuturist.com/what-can-you-achieve-with-crispr-therapy/ It’s time to talk about the ethics of CRISPR-edited human embryos https://geneticliteracyproject.org/2017/08/17/time-talk-ethics-crispr- edited-human-embryos/ What Colud CRISPR Do Tomorrow? http://medicalfuturist.com/what-could-crisprcas9-do-tomorrow/ Questions and Answers about CRISPR https://www.broadinstitute.org/what-broad/areas-focus/project-spotlight/questions-and-answers- about-crispr “First Human Embryos Edited in U.S.” https://www.technologyreview.com/s/608350/first-human-embryos-edited-in-us/ Ethical Issues in Genome Editing using Crispr/Cas9 System https://www.omicsonline.org/open-access/ethical-issues-in-genome-editing- using-crisprcas9-system-2155-9627-1000266.php?aid=70914 59 30  4.12.2024 Stem Cells and Tissue Engineering 1 Tissue engineering Tissue Engineering evolved from the field of biomaterials development and refers to the practice of combining scaffolds, cells, and biologically active molecules into functional tissues. The goal of tissue engineering is to assemble functional constructs that restore, maintain, or improve damaged tissues or whole organs. Artificial skin and cartilage are examples of engineered tissues that have been approved by the FDA; however, currently they have limited use in human patients. 2 1  4.12.2024 Regenerative Medicine Helping the body to heal itself Tissue Engineering Cell Therapy Regeneration 3 4 2  4.12.2024 Artificial skin made from cowhide, shark cartilage and plastic has been successfully used by doctors at the Massachusetts General Hospital in Boston to replace skin destroyed by burns. 5 Regenerative Medicine/Tissue Engineering A field of research for over 70 years. Why so few clinical advances? Inability to expand cells in vitro. Inadequate biomaterials Inadequate vascularity 6 3  4.12.2024 Inability to expand cells in vitro Early 1990s-Most human cells could not be grown or expanded outside of the body. 7 Inadequate Biomaterials 8 4  4.12.2024 Vascularity Problem Cells alone can not survive in volumes greater than 0.3 mm 3 Nutrition to the cells is limited (limited vascularity) 9 Complex Organ Structures Liver Kidney 10 5  4.12.2024 Vaskülarizasyon süreçlerinin nasıl artırılabileceği gösterilmiş. Doku hayatta kalabilirliğini artırmak. 11 12 6  4.12.2024 Components of Tissue Engineering Cells – Living part of tissue – Produces protein and provides function of cells – Gives tissue reparative properties Scaffold – Provides structural support and shape to construct – Provides place for cell attachment and growth – Usually biodegradable and biocompatible Cell Signaling – Signals that tell the cell what to do – Proteins or Mechanical Stimulation 13 Components of Tissue Engineering Repair/replace damaged tissues – Enhance natural regeneration Cell Source Embryonic stem cells Tissue stem cells Progenitor cells Signals Scaffold Growth factors Metals Drugs Ceramics Mechanical forces Synthetic polymers Natural polymers 14 7  4.12.2024 Components of Tissue Engineering 15 Components of Tissue Engineering Porous Scaffolds 16 8  4.12.2024 Important Variables Delivery – Cell Suspensions Modify Cell – Tissue-like constructs (scaffolds) Behavior Chemical properties Survival – Growth factors Organization Migration – Degradation particles Proliferation – Matrix surface Differentiation Physical properties – Structure – Topography Optimize Cellular – Rigidity Response – Mechanical Loading 17 Key Chalenges Good sources: cells / scaffolds Complex tissues Vascularization In vivo functionality Cost efficient/scalable GMP/regulatory compliance 18 9  4.12.2024 19 20 10  4.12.2024 Stem Cell Sources Autologous: Come from the person that needs the new cells. Allogeneic: Come from a body from the same species. Xenogenic: Come from a different species then the organism they’re going into. Isogenic (Syngenic): Come from identical twins. 21 22 11  4.12.2024 23 24 12  4.12.2024 25 26 13  4.12.2024 FACS can be used to purify differentiated stem cells populations. But if there is no specific cell surface marker? FACS (Fluorescence-Activated Cell Sorting) can indeed be used to purify differentiated stem cell populations, but its effectiveness relies on the presence of specific cell surface markers that differentiate the cells of interest from others in the population. If there is no specific cell surface marker available, it becomes challenging to isolate and purify the desired stem cell population using FACS. 27 Purification Fluorescence-activated cell sorting (FACS) Magnetic Cell Sorting (MACS) Adhesion-Based Cell Sorting Complement Depletion Viral Labeling …….. Overview Cell separation: https://app.jove.com/science-education/v/13371/overview-of-cell-separation- and-isolation 28 14  4.12.2024 Video 1: FACS 29 Purification Spesific surface marker MACS Video 2: MACS 30 15  4.12.2024 31 32 16  4.12.2024 Scaffold Purpose Temporary structural support Structural – Maintain shape Cellular microenvironment Surface coating – High surface area/volume – ECM secretion – Integrin expression – Facilitate cell migration 33 Ideal Extracellular Matrix 3-dimensional Cross-linked Modulate Properties Porous Physical, Chemical Customize scaffold Biodegradable Proper surface chemistry Matching mechanical strength Biocompatible Promotes natural healing Appropriate Trade-offs Tissue Accessibility Disease condition Proper architecture Commercial Feasibility 34 17  4.12.2024 Example scaffolds for bone tissue engineering Carbohydrate Polymers 164 (2017) 200–213, Sevim Isik at al. 35 Delivery Methods Injectable stem cells – Cells or cell-polymer mix – Less invasive – Adopt shape of environment – Controlled growth factor release Solid scaffold manufacturing – Computer-aided design – Match defect shape 36 18  4.12.2024 37 38 19  4.12.2024 “Natural” Materials Polymers Perfusion-decellularized matrix: using nature's platform – Collagen to engineer a bioartificial heart. Ott, et al. – Laminin Nat Med. 2008 Feb;14(2):213 – Fibrin – Matrigel – Decellularized matrix Ceramics – Hydroxyapatite – Calcium phosphate – Bioglass 39 Materials for Tissue Engineering Acellular tissue matrix Bioengineering of Organs cadaveric rat hearts Ott HC et al., Perfusion-decellularized matrix: using nature's platform to engineer a bioartificial heart, Nature Medicine, 2008 40 20  4.12.2024 Decellularized matrix WPI Team Grows Heart Tissue on Spinach Leaves Researchers turn to the vascular system of plants to solve a major bioengineering problem blocking the regeneration of human tissues and organs. March 22, 2017 Media Contact Michael Cohen 508-868-4778 Video 2-Living skin substitutes [email protected] 41 Challenge To identify the best material, configuration and coating is needed for optimal construction of each target tissue 42 21  4.12.2024 Cell attachment and cell viability of hMSCs on chitosan scaffolds 43 44 22  4.12.2024 Laboratuvarda olgun hücre ve dokular elde edilebilse de, bunları insanlara nakledecek kadar büyük miktarda üretmek için biyoreaktörler, 3D biyoyazıcılar, scaffold (iskelet) yapıları ve ko-kültür sistemleri gibi teknolojiler kullanılır. Bu süreçte hücre proliferasyonu, büyüme faktörleri, fiziksel uyarılar (mekanik veya elektriksel) ve damarlaşmayı (vaskülarizasyon) artırıcı yöntemler kritik öneme sahiptir. Ayrıca organoidlerin veya küçük doku birimlerinin füzyonu, daha büyük ve fonksiyonel yapılar oluşturmak için bir 45çözüm sunar. Ancak oksijen ve besin taşınımı, hücre sayısının artırılması ve fonksiyonel damarlaşma gibi zorluklar, bu teknolojilerin daha da geliştirilmesini gerektirir. 46 23  4.12.2024 47 This is an image of pancreatic islet cells encapsulated by an alginate bead. These beads are rather large and contain much than just one cell per bead. The bead diameter can vary greatly (from 25 micrometers to several millimeters). 48 24  4.12.2024 49 50 25  4.12.2024 51 52 26  4.12.2024 53 Hücreler veya 54doku mühendisliği ile üretilen yapılar teratom (tümör benzeri anormal hücre büyümesi) oluşturmadan canlı bir organizmada bir defekti düzeltebilir, ancak bu durum hücrelerin tipi, farklılaşma durumu ve nakil sonrası mikroçevre gibi faktörlere bağlıdır 27  4.12.2024 55 56 28  4.12.2024 57 58 29  4.12.2024 59 Regenerative Medicine Pioneers Wake Forest Institute for Regenerative Medicine (WFIRM) Dr. Anthony Atala 2006-2007: First to Engineer/Transplant Lab-Grown Organ into a Human Transplant was Successful 60 30  4.12.2024 Regenerative Medicine Pioneers Dr. Paolo Macchiarini (Karolinska Institute) 2008: Implanted World’s First Donor Trachea Recipient: Claudio Castillo Survived Procedure — Now Has Normal Respiratory Function 61 Regenerative Medicine Pioneers Dr. Ali Khademhosseini (Wyss Institute at Harvard) [MIT Technology Review:ww2.technologyreview.com/tr35/profile.aspx?TRID=610] 2007: Creating living tissues Personalized 3D Vascular Constructs 62 31  4.12.2024 Regenerative Medicine Pioneers McGowan Institute of Regenerative Medicine (University of Pittsburg) Dr. Stephen Badylak Re-grows Severed Digits and New Muscle Tissue Development of 3-D bioscaffolds for liver and heart regeneration 63 Regenerative Medicine Pioneers Dr. Geraldine Hamilton (Wyss Institute, Harvard) 2011: Organ on a Chip Technology (Drug Testing Tool) 64 32  4.12.2024 Potential of Regenerative Medicine Chip Technology [Geraldine Hamilton, Body parts on a chip, TEDx Boston, June 2013: https://youtu.be/CpkXmtJOH84] Reduces Need for Animal Testing 3-D Printed Organs on Chips Used to Test Vaccines 65 66 33  4.12.2024 Regenerative Medicine Innovators Dr. Jordan Miller (Rice University) 2013: Uses 3-D Print Technology Engineers Blood Vessels Using Sugar 67 Promise of Regenerative Medicine 3-D Printer Creates Heart Membrane [Prof. Igor Efimov, Washington University in St. Louish: ttps://news.wustl.edu/news/Pages/26554.aspx] Lizhi Xu and al., Nature Communications, 2014, 3329, doi:10.1038/ncomms4329 3-D Elastic Membrane Fits Heart’s Epicardium Video 3-Tissue engineering by 3D printers 68 34  4.12.2024 3D Printed Ear by Direct Ink Write (DIW) Technique 69 Futuristic! Stem Cells + Organ Scaffold + 3D Printer = Libraries of Replacement Organs? 70 35  4.12.2024 Related Video Links https://www.jove.com/video/2561/isolation-and-culture-of-adult-epithelial-stem-cells-from-human-skin https://www.jove.com/video/3194/isolation-culture-neural-crest-stem-cells-from-human-hair https://www.youtube.com/watch?v=GqJYMgAcc0Q http://www.youtube.com/watch?v=F7WTe7_m76g http://www.youtube.com/watch?v=GwcT1ViM-hw&NR=1 http://www.youtube.com/watch?v=0taE4F0Wkhg&feature=related 71 36  Cancer Stem Cells Stem Cells: The Good and The Bad 1 What is cancer? Cancer is a group of diseases characterized by unregulated cell growth and the invasion and spread of cells from the site of origin, or primary site, to other sites in the body. Carcinomas: cancers occur in epithelial cells (85%). Sarcomas: cancers derived from mesoderm cells (e.g. bone, muscle) Adenocarcinomas: cancers of glandular tissue (e.g. breast). Cancers of different origins have have distinct features such as causes and carcinogenesis. For example, skin cancer has many characteristics that differ from lung cancer. 2 1  Cancer is a Disease of the Genome at the Cellular Level Carcinogens: agents that cause cancer. Mutagens: cause alterations to the DNA sequence or mutations. Most of the identified agents known to contribute to the causation of cancer, including ionizing radiation and most chemical carcinogens, are mutagens: they cause changes in the nucleotide sequence of DNA. Cancer is fundamentally a genetic disease: it arises as a consequence of pathological changes in the information carried by DNA. It differs from other genetic diseases in that the mutations underlying cancer are mainly somatic mutations. Many alterations in DNA ranging from subtle point mutations (changes in a single base pair) to large chromosomal aberrations, such as deletions and chromosomal translocations. 3 Cancer is a Disease of the Genome at the Cellular Level The accumulation of mutations in cells over time represents a multi-step process that underlies carcinogenesis. Environmental carcinogens other than tobacco smoke probably account for only a small fraction of the mutations responsible for cancer. Spontaneous mutations occur at an estimated rate of about 10–6 or 10–7 mutations per gene per cell division due to mistakes in replication, even without encouragement by external mutagens. Cancers Develop by an Accumulation of Mutations ! 4 2  Benign Versus Malignant Adenoma --- adenocarsinoma Condroma --- condrosarcoma A benign tumor is not evidence of cancer. Benign tumors do not spread throughout the body (that is, they do not metastasize), although some can be life threatening because of their location (e.g. a benign brain tumor that may be difficult to remove). Malignant tumors, on the other hand, do not remain encapsulated, show features of invasion, and metastasize. Figure 20-3 Molecular Biology of the Cell (© Garland Science 2008) 5 Cancer Cells and Metastasis Placement of cancer cells to liver http://www.childrenshospital.org/research/_cancer/index.html Figure 20-17 Molecular Biology of the Cell (© Garland Science 2008) http://www.bio-alive.com/categories/angiogenesis/angiogenesis1.html 6 3  Cancers Develop by an Accumulation of Mutations 2015 Cancer is most often a disease of old age, because it takes a long time for an individual clone of cells—those derived from a common founder—to accumulate a large number of mutations 7 Genetic Instability of Cancer Cells Most human cancer cells not only contain many mutations, but they are also genetically unstable. Genetic instability results from mutations that interfere with the accurate replication and maintenance of the genome increase the mutation rate A Variety of Factors Can Contribute To Genetic İnstability Defects in DNA replication Defects in DNA repair Defects in cell-cycle checkpoint mechanisms Mistakes in mitosis Abnormal chromosome numbers 8 4  Genetic Instability of Cancer Cells Genetic instability can generate extra chromosomes, as well as chromosome breaks and rearrangements—gross abnormalities that can be seen in a karyotype Essential Cell Biology 4th edition, Figure 20-46 Cancer cells often have highly abnormal chromosomes, reflecting genetic instability. In the example shown here, chromosomes were prepared from a breast cancer cell in metaphase (A) a general DNA stain or (B) a combination of fluorescent stains that give a different color for each human chromosome. The staining (displayed in false color) shows multiple translocations, including one chromosome (white arrow) that has undergone two translocations, so that it is now made up of two pieces of chromosome 8 (olive) and a piece of chromosome 17 (purple). The karyotype also contains 48 chromosomes, instead of the normal 46. 9 Mutations Enhance Cell Proliferation and Cell Survival Tumors evolve by repeated rounds of mutation and proliferation. The final outcome is a fully malignant tumor. At each step, a single cell undergoes a mutation that enhances its ability to proliferate, or survive, or both, so that its progeny become a dominant clone in the tumor. Proliferation of this clone then hastens occurrence of the next step of tumor progression by increasing the size of the cell population at risk of undergoing an additional mutation. Essential Cell Biology 4th edition, Figure 20-47 10 5  Hallmarks of Cancer Six Fundemental Changes o Self sufficiency in growth factors o Insensivity to growth-inhibitory signals o Evasion of apoptosis o Limitless replicative potential o Sustained angiogenesis o Ability to invade and metastasize 11 Cancer Cells Evolve Properties that Give Them a Competitive Advantage Key behaviors of cancer cells that distinguish them from normal cells: -- they have reduced dependence on signals from other cells for growth, survival and division. --Ras gene --they are less prone than normal cells to kill themselves by apoptosis. --p53 protein --immortal. -- high telomerase enzyme activity. --genetically unstable. --abnormally invasive. They can often survive and proliferate in foreign tissue to form secondary tumours wheras most normal cells die when misplaced. Figure 20-46 Essential Cell Biology (© Garland Science 2010) 12 6  A Key Observation: All Cancer Cells Are Not Equal Label cells with antibodies for the cell surface molecules CD24 and CD44 – sort by flow cytometry. Excise cancer from Breast Isolate Cancer cells Inject mice 103 104 105 106 cells cells cells cells No No No Tumor Tumor Tumor Tumor Figure 11.14a The Biology of Cancer (© Garland Science 2007) 13 The Cancer Stem Cell Hypothesis Tumors are functionally heterogeneous and hierarchical. They are composed of cells that can initiate tumors (tumor initiating cells or cancer stem cells) and cells that arise from CSCs but cannot initiate tumors. The frequency of CSC in a tumor is highly variable (often low). Cancer stem cells can (in many cases) be prospectively identified. Cancer stem cells may have different sensitivities to radiation or chemotherapy. Therefore, the concept of CSCs has significant clinical implications. 14 7  Cancer Stem Cells Immortal tumor-initiating cells that can selfrenew and have pluripotent capacity Can generate tumor cells with different phenotypes, which results in the growth of the primary tumor and emergence of new tumors. Found in multiple malignancies, including leukemia and various solid cancers (breast, lung cancer, colon cancer, prostate cancer, ovarian cancer, brain cancer, and melanoma). 15 Stem Cells: Not like other cells… Self Renewal Stem Cell Stem Cell Progenitor Cell Undifferentiated Cell division and differentiation Red Blood Cell Platelet White Blood Cell 16 8  Adult stem cells: Many different types… Adult stem cells contribute to homeostasis Neural They divide only Stem Cell when needed Their progeny differentiate into cells that perform essential body functions. Blood Stem Cell 17 Cancer Stem Cells Cancer Stem Cell DNA mutations Cancer Cancer Progenitor Stem Cell Cell Uncontrolled, rapid cell division gives rise to improperly differentiated tumor cells 18 9  Where might cancer stem cells come from? Mutations in somatic stem cells adult progenitor cells adult somatic cells/cancer cells 19 Origin of Cancer Stem Cells EMT: Epithelial-mesenchymal transition Role of miRNA-Regulated Cancer Stem Cells in the Pathogenesis of Human Malignancies, 2019, Cells, 8(8):840, DOI:10.3390/cells8080840 20 10  Cancer Stem Cells Tumor Cancer Stem Cancer/Somatic Tıssue Cell Cell Stem Cell/Progenitor Cell Drug Resistance and 3 Key Cancer Relapse Processes Growth and - Quiescent Proliferation Metastatic - Resistant to in NOD/SCID Dissemination chemotherapy mice -Relaps 21 Where might cancer stem cells come from? DNA mutations in normal stem cells may give rise to cancer stem cells 22 11 23 24 12 25 Characteristics of CSCs targeted for developing therapeutic and bio-imaging agents 26 13  CSC Features self-renewal diverse progeny asymmetric division immortality 27 Significance in clinics metastases formation chemotherapy resistance radiotherapy resistance reccurence 28 14  Characteristics of CSCs, cancer cells, and normal cells Cancer stem cell-targeted bio-imaging and chemotherapeutic perspective, Chemical Society Reviews, 21 November 2020, Issue 22, Page 7847 to 8392 29 Chemotherapy: Targets Rapidly Dividing Cells Stem cells do not divide rapidly, so are not targeted by chemotherapy. Conventional chemotherapy targets rapidly dividing cells. X X X 30 15  Chemotherapy: Targets Rapidly Dividing Cells Tumor treated with chemotherapy The stem cell Cancer Stem Cell survives conventional chemotherapy and divides to form a new tumor 31 What’s coming in cancer therapy? New targeted drugs that The rest of the cancer specifically kill cancer cells should die on their stem cells without own, or conventional harming normal stem chemotherapy drugs can cells should remove the be used to kill these cells “root” of the cancer. 32 16  Scientists are searching for answers to these questions about cancer stem cells… What makes these cells different? What kinds of drugs can target these cells? What cellular pathways are affected by drugs that target these cells? Are there other possible drugs that target those pathways? 33 Methods of Isolating CSCs 1. Side population 2. Establishment culture 3. Cellular markers 34 17  1- Side population The Hoechst side population (SP) method is a flow cytometry technique used to obtain stem cells based on the dye efflux properties of the ATP-binding cassette (ABC) transporters. The SP cells are characterized by their capability to efflux the fluorescent DNA-binding dye Hoechst 33342 through their ABC transporters. After dissociation and staining cells of blood and solid organs, all cells take it up, but CSCs export the dye out with high efflux efficiency 35 ABC Transporters ATP-binding cassette (ABC) transporters are membrane transporters that can pump various distinct and structurally unrelated small molecules (such as cytotoxic drugs and dyes) out of cells at the expense of ATP hydrolysis Anti–tumor drugs can be pumped out, thereby resulting in low intracellular drug concentrations. Thus, the elevated levels of ABC transporters enable cancer stem cells to resist current cancer therapies 36 18  ABC Transporters The involvement of ABC transporter proteins in chemoresistance. OMICS A Journal of Integrative Biology Volume 22, Number 1, 2018, DOI: 10.1089/omi.2017.0174 37 2- Establishment culture The ability of CSCs to create spheres after they were cultured, is another method for dissociating these cells The best way of isolating CSCs from digested tumor tissue is culturing the cells in serum-free medium, which is named as spheroid colony formation. Immature cells grows slowly and form non-adherent clusters called tumor spheres while non-malignant cells or differentiated cells die 38 19  3-Cellular Markers TABLE Isolation and identification of cancer stem cells in tumors using various markers Cell Surface Markers: CD44 and CD133 molecules are two common surface markers used for identification and isolation of CSCs. CD44, a transmembrane glycoprotein, which is expressed in leukocytes, endothelial cells, hepatocytes, and mesenchymal cells,plays a significant role in binding to extracellular matrix, cell migration, and differentiation. CD133, also known as prominin-1, is a transmembrane glycoprotein, it is expressed in embryonic epithelial stem cells and hematopoietic stem cells EpCAM (Not CD): is transmembrane glycoprotein mediating Ca2+- independent homotypic cell–cell adhesion in epithelia. EpCAM is also involved in cell signaling, migration, proliferation, and differentiation. Additionally, EpCAM has oncogenic potential via its capacity to upregulate c-myc, e-fabp, and cyclins. Intracellular Markers: Aldehyde dehydrogenase 1 (ALDH1) Oct3/4 Nanog 39 Cancer Stem Cell Markers 40 20  Isolation Limitations of Cancer Stem Cells with Markers Although dissociation of the desired cell population using cellular markers is more specific than the spheroids formation, it has several limitations. ❖ the number of isolated cells is limited necessitating the use of more cells which is difficult due to the small size of tumor. ❖ because tumor tissues are treated with enzymes, most of the surface antigen will be damaged and perhaps this is considered as the biggest disadvantage of the use of surface markers to isolate cancer stem cells ❖ some factors such as the low viability of isolated cells, high cost and the difficulty of using complex equipment can be named as other disadvantages. 41 TUMORIGENICITY Ability of CSCs to form a tumor in vivo, in an immunodeficient mice, has become a standard to identify them, especially in solid tumors Two immunodeficient mouse models, including nude and NOD/SCID mice which do not reject xenografts, are often used for analysis of the tumorigenicity. The nude mouse model is athymic, hairless, and it lacks mature T cells due to mutations in the FOXN gene The NOD/SCID mouse model created by crossing between the SCID mouse which lacks B and T lymphocytes and the NOD mouse which lacks natural killer cells (NK cells) and antigen-presenting cells (APC). Limiting dilution assays (LDA) as gold standard commonly used to estimate active CSC frequencies 42 21  TUMORIGENICITY Limiting dilution assays (LDA): Limiting dilution analysis attempts to determine the frequency of cells (CSCs) having a particular function that are present in a mixed population of cells. So limiting dilution analysis is an easy- operated method that used to measure the abundance of cells able to perform a particular function. 43 Identifying Cancer Stem Cells Scientists can break up the cells of a tumor, then transplant each tumor cell into a new location…. Most of the tumor cells end up dying… Tumor But a rare few go on to grow a new tumor… Cancer Stem Cells 44 22  SELF-RENEWAL The CSC must have the ability to sustain itself and continue to lead to cells with equal capabilities of tumorigenicity and recapitulation of the original tumor. This capability of the CSC resulting in another CSC is termed self-renewal. Serial transplantation of a tumor is the most rigorous proof of the capability of the CSC to self-renewal. Serial transplantation comprises isolating the CSCs from any generation of a tumor in a mouse model and testing tumorigenicity with isolated CSCs, leading to the formation of a subsequent tumor 45 The Notion of Cancer Stem Cells Essential for the initiation and long term maintenance of the tumor Responsible for the expansion of the tumor – incapable of long term maintenance of the tumor. Perhaps post-mitotic in some cases, in others, further proliferation is possible. Much of the tumor cell population Incapable of maintaining the tumor. Adapted from: Figure 11.16b The Biology of Cancer (© Garland Science 2007) 46 23  Cancer Stem Cells & Metastasis 47 Cancer Stem Cells (CSCs) Cells with stem-like behaviors have been found in the following cancers and others as well: Breast Cancer; Colon Cancer; Leukemia; Prostate Cancer; Melanoma; Pancreatic Cancer & Some Malignant Brain Tumors Implications for therapy * Cure of cancer may require elimination of the minority cancer stem cell population of the tumor as well as the non-CSC majority of cancer cells. "It's like dandelions in the back yard: You can cut the leaves off all you want, but unless you kill the root, it will keep growing back.“ John Dick, leader of the team that discovered colon and leukemia CSCs * The possibility that different therapies may be needed to eliminate cancer stem cells complicates the search for definitive cures. For example, some CSCs appear to be more resistant to radiation than other cells of the tumor 48 24  PERSPECTIVES ▪ THERAPY ▪ DIAGNOSTICS 49 TARGETED THERAPY 50 25  Figure 1. The concept of the cancer stem cell (CSC). Tumor cells are heterogeneous which contain a majority of cells are non/-poorly tumorigenic, and a small subset of CSCs. The CSCs can be functionally distinguished from other populations by their ability to reconstitute a differentiated tumor upon transplantation into an immunocompromised mouse. Based on this model, CSC specific therapies are proposed in combination with conventional chemotherapies to kill both CSC and other differentiated populations and prevent subsequent relapse. STEM CELLS TRANSLATIONAL MEDICINE 2019;8:75–81 51 Implications of CSC Resistance to Antitumor Treatment 52 26  Possible Therapeutic Strategies that Can Eliminate CSCs Nanomedicine-mediated cancer stem cell therapy , Biomaterials, Volume 74, January 2016, Pages 1-18 53 Novel Therapeutic Strategies For Targeting Cancer Stem Cells Therapeutic strategies for targeting cancer stem cells, J Cancer Metastasis Treat 2016;2:233-42. doi: 10.20517/2394- 4722.2016.26 54 27  Possible Cancer Stem Cell Targeted Treatments Agents targeting signaling pathways involved in the self renewal of cancer stem cells Wnt/β-catenin signaling pathway Hedgehog signaling pathway Notch signaling pathway PTEN TGF-β signaling pathway (JAK/STAT) PI3K/Akt ABC Superfamily 55 Immunological based approches ▪ Antibodies targeting cancer stem cell surface markers ▪ Chimeric Antigen Receptor Targeting (CART cell targeting) ▪ Especially CD133 marker Recruting Immune system Allogenic bone marrow transplantation 56 28  MSC-based Approach For Cancer Therapy Application of Mesenchymal Stem Cells for Therapeutic Agent Delivery in Anti-tumor Treatment, Front. Pharmacol., 20 March 2018 | https://doi.org/10.3389/fphar.2018.00259 57 29  24.12.2024 Stem Cell Therapeutics for Cancer 1 Video 1-Mechanism of Action of Cell-based Therapies 2 1  24.12.2024 Hematopoietic Stem Cells in Treatment of Cancer 3 Hematopoietic stem cell transplantation It is the process of transplanting multipotent hematopoietic stem cells, mostly from peripheral blood, bone marrow or umbilical cord blood. Hematopoietic stem cell transplantation was first used in the treatment of some types of cancer, but today it is widely used for the treatment of various autoimmune diseases. United States Food and Drug Administration (FDA) has approved hematopoietic stem cell transplantation (HSCT) 4 2  24.12.2024 What is Stem Cell Transplantation Used in Treatment? Stem cell transplantation has been approved for the treatment of various cancers: multiple myeloma, leukemia and some lymphomas. In addition, HSCT is used to treat autoimmune diseases in many specialist clinics around the world. Perhaps the most notable of these is multiple sclerosis. An extremely high success rate for this treatment has been claimed but is still considered experimental. 5 Cancer Consists of Three Main Stages development, growth, metastasis. The most important factors in the initiation of cancer are the epigenetic changes, genetic mutations in proto-oncogenes, tumor suppressor genes, pro-apoptotic, anti-apoptotic, and cell cycle controlling genes. 6 3  24.12.2024 tumor microenvironment growth, chemotherapy resistance, immune escape, and tumor metastasis Angiogenesis --- (vascular endothelial growth factor (VEGF and its receptors) in tumor site is necessary for tumor growth and metastasis *** resistance to chemotherapies and vasculogenic mimicry*** 7 Advantages of MSCs For Medical Applications in The Case of Cancer Therapy Some of the superiorities of using MSCs as therapeutic gene micro-carriers: ✓ easy cell-extraction procedures ✓ their abundant proliferation capacity in vitro without losing their main biological properties ✓ tumor-tropism, ✓ non-immunogenicity, ✓ stimulatory effect on the anti-inflammatory molecules, ✓ inhibitory effect on inflammatory responses, ✓ non-toxicity against the normal tissues, and easy processes for the clinical use 8 4  24.12.2024 Approaches For Gene Therapy of Cancer 1. Engineered chimeric antigen receptor (CAR) T cells; CARs are engineered receptors with high specificity in identifying tumor-related antigens. 2. Tumor vaccine (DNA vaccine), DNA vaccines can establish anticancer immunity through the induction of expression of a specific gene. 9 1- Engineered Chimeric antigen receptor T cells (also known as CAR T cells) CART cells are T cells that have been genetically engineered to produce an artificial T-cell receptor for use in immunotherapy. CARs are receptor proteins that have been engineered to give T cells the new ability to target a specific protein. The receptors are chimeric because they combine both antigen-binding and T-cell activating functions into a single receptor. Video 2-CAR T-Cell Therapy- How Does It Work 10 5  24.12.2024 CART cells for cancer therapy CAR-T cell therapy uses T cells engineered with CARs for cancer therapy. The premise of CAR-T immunotherapy is to modify T cells to recognize cancer cells in order to more effectively target and destroy them. CAR-T cells can be either derived from T cells in a patient's own blood (autologous) or derived from the T cells of another healthy donor (allogeneic). For safety, CAR-T cells are engineered to be specific to an antigen expressed on a tumor that is not expressed on healthy cells. 11 Ideal CAR Target… Tumor specific Universally expressed on only tumor cells Cell surface molecule CD19 antigen, – Found on B cell malignant cells (Non-hodgkin lymphoma (NHL), Acute lymphocytic leukemia (ALL), Chronic Lymphocytic leukemia (CLL), etc) – Expressed on early B cells but NOT stem cells 12 6  24.12.2024 2. Tumor vaccine (DNA vaccine) DNA vaccines for cancer immunotherapy are designed to deliver one or several genes encoding tumor antigens, thereby eliciting or augmenting antigen-specific immune responses against antigens that play a central role in tumor initiation, progression and metastasis. 13 Cancer Vaccines Active and specific stimulation of immune system against cancer Therapeutic Increased tumor antigen recognition 10% of Reduced immune tolerance Preventive cases Human Papilloma Virus (HPV) Cervical cancer Tumor Antigens Hepatitis B virus (HBV) Hepatocellular carcinoma 25% of Nonpathogenic virus cases İdiotype antibodies Vaccines 70% Tumor Anti HPV reduced risk Associated Anti HBV Lymphocytes Cancer cells Antigen presenting cells Vaccines: Melanoma Prostate Cancer Follicular lymphoma Tumor associated lymphocytes: A type of immune cell that has moved from the blood into a tumor 14 7  24.12.2024 15 Preventive Cancer Vaccines Viral infections are responsible for the development of several cancers and preventive vaccines play an important role in reducing risk. For instance, cervical cancer and head and neck cancer can be caused by human papilloma virus, or HPV, whereas liver cancer can be caused by hepatitis B virus or HBV. Several vaccines have been developed that can prevent HBV and HPV infection and, as a result, protect against the formation of HBV- and HPV-related cancers. Four of these preventive cancer vaccines have been approved by the U.S. Food and Drug Administration (FDA). 16 8  24.12.2024 Preventive Cancer Vaccines Cervarix®: a vaccine approved for use in preventing infection by the two strains of HPV that cause most cervical cancers, HPV types 16 and 18; can help prevent the development of HPV-related anal, cervical, head and neck, penile, vulvar, and vaginal cancers Gardasil®: a vaccine that protects against infection by HPV types 16, 18, 6, and 11; can help prevent the development of HPV-related anal, cervical, head and neck, penile, vulvar, and vaginal cancers Gardasil-9®: a vaccine approved for the prevention of infection by HPV types 16, 18, 31, 33, 45, 52, and 58, and for the prevention of genital warts caused by HPV types 6 or 11; can help prevent the development of HPV- related anal, cervical, head and neck, penile, throat, vulvar, and vaginal cancers Hepatitis B (HBV) vaccine (HEPLISAV-B®): a preventive vaccine that protects against infection by the hepatitis B virus; can help prevent the development of HBV-related liver cancer 17 Therapeutic Cancer Vaccines Each individual’s tumor is in some sense unique and has its own distinguishing antigens. As a result, more sophisticated cancer vaccine approaches are necessary. Fortunately, scientists now identify targets on patients’ tumors that can help distinguish cancer cells from their normal cells. Sometimes these targets are normal proteins that are produced at abnormally high levels by cancer cells, such as prostatic acid phosphatase (PAP), which is often overexpressed by prostate cancer cells. Taking advantage of that insight, the sipuleucel-T vaccine was developed and received FDA approval in 2010 for the treatment of patients with advanced prostate cancer. Additionally, virus-derived proteins expressed by virus-infected cancer cells offer another promising source of markers that can be targeted through vaccines. Another exception is Bacillus Calmette-Guérin, or BCG, a tuberculosis vaccine that acts as a general immune stimulant. In 1990, BCG became the first immunotherapy of any type to be approved by the FDA and is still used for the treatment of early-stage bladder cancer. 18 9  24.12.2024 Therapeutic Cancer Vaccines Bacillus Calmette-Guérin (BCG): a vaccine that uses weakened bacteria to stimulate the immune system; approved for patients with early-stage bladder cancer Sipuleucel-T (Provenge®): a vaccine composed of patients’ own stimulated dendritic cells; approved for prostate cancer Prostate Cancer vaccine: https://www.cast-pharma.com/portfolio/prostate-cancer-vaccine/ 19 Vaccine Induced Immune Responses 1 Antigens derived from tumor itself or virus infected cells 2 3 4 20 10  24.12.2024 Mechanisms of Action of DNA Vaccines 21 Approaches For Gene Therapy of Cancer 3. Replacing the normal hematopoietic stem cells; the normal cells are transfected with specific chemotherapy-resistant genes then transplanted to the patient by bone marrow transplantation. 4. Clustered regularly interspaced short palindromic repeats (CRISPR)–Cas9 technology; 22 11  24.12.2024 Approaches For Gene Therapy of Cancer 5. Therapeutic genes/agents delivery; viral and non-viral vectors, tumor-tropic cells, and other micro-carriers are used for the transfer or expression of therapeutic genes, agents, or even oncolytic viruses Delivered anticancer factors: tumor suppressor genes, apoptosis-inducing genes, suicide genes, regulatory agents [e.g., RNA interference (RNAi), miRNAs], oncolytic viruses and immunological factors (e.g., cytokines) 23 Therapeutic genes can be transferred as the naked DNA or by using viral/non-viral vectors. But the main disadvantage of this classical method of gene delivery is its generally non-selective nature. Transgene MSCs selectively migrate toward the injured and tumor site(s) tropism to tumor sites and immunomodulatory properties of MSCs 24 12  24.12.2024 The Strategies Applied for the Anti-cancer Genes/Agents Delivery are Based on the Following Principles 1. Augmentation gene therapy (a) expressing a gene to prompt apoptosis (e.g., TRAIL, mda-7, Caspases and selective short interfering RNA (siRNA)/microRNA (miRNA)- mediated blocking of anti- apoptotic genes), (b) improving tumor sensitivity to chemo/ radiation therapy, (c) introducing a tumor suppressor gene (e.g., P53, Rb, p16INK/CDKN2, and PTEN). 25 2. Gene silencing therapy: inhibition of expression of an oncogene (C-MYC and K- Ras) by employing an antisense (RNA/DNA). 3. Suicide gene therapy: delivery of a converting enzyme to the site of tumor that convert non-toxic prodrug to the toxic drug. 4. Immuno-gene therapy: increasing the immunogenicity of the tumor cells/tissue to stimulate immune cell response against tumor. Video 3-Oncolytic Virus Therapy- Dynamite for Cancer Cells 26 13  24.12.2024 The Strategies Of Anticancer Gene Therapy Using Mesenchymal Stromal/Stem Cells (Mscs) As Gene Vehicles 27 The Mechanisms of MSCs Homing to Tumor Tissue Tumor cells resemble a chronic inflammation within the tumor microenvironment by generating high concentrations of inflammatory chemokines and growth factors. Selective migration of MSCs to the tumor site is linked to the high local concentrations of dozens of chemoattractants and growth factors that are secreted by tumor cells and inflammatory cells. 28 14  24.12.2024 The Mechanisms of MSCs Homing to Tumor Tissue MSCs can migrate to sites of trauma, injury and tumor gradient of chemo-attractants in the extracellular matrix (ECM) and peripheral blood (Son et al., 2006) and local factors, such as hypoxia, cytokine environment and Toll-like receptors ligands, where upon arrival these local factors promote MSCs to express growth factors that accelerate tissue regeneration (Rustad and Gurtner, 2012). 29 The Mechanism of Mesenchymal Stromal/Stem Cells (MSCs) Migration/Homing Toward Injured/Cancer Tissues 30 15  24.12.2024 Increasing the efficiency of Tumor Tropism of MSCs low-dose irradiation of tumor can increase the recruitment of MSCs to the tumor site(s). irradiation increases the apoptosis and stimulates the danger signals. The danger signals thereby induce the production of inflammatory cytokines such as PDGF, TNFα, CCR8, and CCR2 within the tumor microen-vironment, and consequently enhance MSCs swarming into the tumor location(s) 31 Genetically Engineered MSCs With Anticancer Activity MSCs genetically modified with interferon β (IFN-β) were injected into human melanoma mouse xenotransplantation models which resulted in decreased tumor growth and increased (2-times) survival of mice in comparison with controls (Studeny et al., 2002). One of the most promising therapeutic pro-apoptotic cytokines is tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), which selectively induces apoptosis in cancer cells. 32 16  24.12.2024 Genetically Engineered MSCs With Anticancer Activity IL-12, CX3CL1, INF-β, INF-α, INF-γ, IL-2, hepatocyte growth factor antagonist NK4, pigment epithelium-derived factor, TRAIL, and TNF-α have antitumor effect. Tumor necrosis factor (TNF)‐related apoptosis‐inducing ligand (TRAIL) is the ligand for death receptors which are expressed on the surface of tumor cells. TRAIL can initiate the caspase- mediated apoptosis leading to inhibition of tumor growth MSCs and generally other normal cells are nearly resistant to TRAIL-induced apoptosis due to very low expression of death receptors. TRAIL-directed death induction can be of great advantages to the designing of a selective cancer therapy 33 Genetically Engineered MSCs With Anticancer Activity Factor Application MSCS Host Vector Tumor model Result 34 17  24.12.2024 Delivery of oncolytic viruses with MSCs For instance, Du et al. (2017) used MSCs as a vector for the delivery of oncolytic herpes simplex virus (oHSV) [approved by Food and Drug Administration (FDA) for melanoma treatment] in human brain melanoma metastasis models in immunodeficient and immunocompetent mice. Authors noted that the introduced MSCs-oHSV migrated to the site of tumor formation and significantly prolonged the survival of mice. 3-Oncolytic Virus Therapy- Dynamite for Cancer Cells 35 MSCs Primed With Anticancer Drugs Mesenchymal stem cells: relative resistance to cytostatic and cytotoxic chemotherapeutic drugs migration ability targeted delivery of therapeutic drugs directly to tumor sites. 36 18  24.12.2024 MSCs Primed With Anticancer Drugs mouse bone marrow stromal cells can be a reservoir for doxorubicin (DOX) which can subsequently be released not only in the form of DOX metabolites but also in its original form. MSCs efficiently absorb and release paclitaxel (PTX) in an active form (Pascucci et al., 2014), DOX, and gemcitabine (GCB), all having an inhibitory effect on tongue squamous cell carcinoma (SCC154) cells growth in vitro (Cocce et al., 2017b). Beside chemical drugs in soluble form, MSCs can absorb nanomaterials containing chemotherapeutic agents. For instance, MSCs primed with silica nanoparticle-encapsulated DOX promoted a significant increase in the apoptosis of U251 glioma cells in vivo (Li et al., 2011). 37 MSCs as Transporters of Therapeutic Molecules Moreover, MSCs are capable of being reprogrammed for transporting therapeutic molecules/proteins in the same manner that they can carry the therapeutic genes. This helps to overcome the adverse effects associated with the direct injection of drugs or other therapeutic molecules. 38 19  24.12.2024 Gene-directed enzyme prodrug therapy (GDEPT) by MSCs At the first stage, the genes encoding the pro- drug activating enzymes are transferred to the tumor site using MSCs as the cell vehicles. Subsequently, inactive and non-toxic prodrug is injected to the body. Then, pro-drug is catalyzed by the enzymatic cleavage to the activated form within the tumor environment. At the last stage, cytotoxic metabolites derived from injected and catalyzed pro-drug are released to the tumor microenvironment causing apoptosis, necrosis and death of the tumor cells 39 Table 2 | Gene-directed enzyme pro-drug therapy (GDEPT) of cancers using the various types of mesenchymal stromal/stem cell (MSCs). herpes simplex virus thymidine kinase (HSV-TK) and ganciclovir (GCV) as a suicide gene therapy strategy cytosine deaminase (CD) gene and the prodrug 5- fluorocytosine (5-FC) BM-MSCs, bone marrow-derived mesenchymal stem cells; AT-MSCs, adipose tissue mesenchymal stem cells; i.v., intravenous; s.c., subcutaneous; dTRAIL, dodecameric human TRAIL; hASCs, human adipose-derived stroma and stem cells; NSCs, neural stem cells, CDy::UPRT, fusion yeast cytosine deaminase::uracil phosphoribosyltransferase gene. Mesenchymal Stromal/Stem Cells: A New Era in the Cell-Based Targeted Gene Therapy of Cancer, 2017, Front. Immunol 40 20  24.12.2024 The Procedures For The Isolation, Culture, Gene Transfer, and In Vivo Administration of The Mesenchymal Stromal/Stem Cells 41 MSC-based Approach For Cancer Therapy Application of Mesenchymal Stem Cells for Therapeutic Agent Delivery in Anti-tumor Treatment, Front. Pharmacol., 20 March 2018 | https://doi.org/10.3389/fphar.2018.00259 42