Cancer Biology Quiz

• The goal of inflammation is to control the inflammatory response from spreading
• Also, the goal is prevent/limit further damage/infection
• To activate adaptive immunity and educate, and to initiate healing.
• Acute inflammation lasts 8-10 days, is self-limiting, and heals without treatment.
• Chronic inflammation lasts more than 2 weeks or is recurring.
• Signs of inflammation include redness/erythema, swelling/edema, pain, heat, and sometimes loss of function.
• Exudative fluid can be serous, fibrinous, hemorrhagic or purulent

Types of Exudative Fluid

• Serous exudative fluid is clear, watery, and present in early inflammation.
• Fibrinous exudative fluid is yellowish, thick/clotted, and present in more advanced inflammation.
• Hemorrhagic exudative fluid is bloody.
• Purulent exudative fluid contains pus, indicating infection.
• Fever is caused by endogenous cytokines or exogenous microbes.
• Cytokines are chemical messages with effects on cells.

Specific Cytokines

• IL-1 is proinflammatory.
• IL-10 is anti-inflammatory.
• IFN alpha and beta are antiviral proteins.
• IFN gamma increases macrophage phagocytosis.
• Leukocytosis increases WBC circulation.
• Macrophages perform phagocytosis and secrete cytokines for the inflammatory response.
• Mast cells mature into macrophages at the inflammation site and release histamine.

Plasma Systems

• Plasma systems involved in inflammation are Kinin, Complement, and Clotting.
• The complement system has 3 pathways: classical, lectin, and alternative.
• Activation of C3 leads to C3a and C3b.
• C3a causes mast cell degranulation.
• C3b causes opsonization and C5 activation
• C5a causes mast cell degranulation and leukocyte migration.
• C5b activates MAC (membrane attack complex).
• Clotting can be extrinsic or intrinsic.
• Extrinsic clotting involves factor VII and TF to factor X.
• Intrinsic clotting involves factor VII to factor X or the Kinin System.
• Factor X leads to thrombin, fibrinogen, fibrin, and a fibrin blood clot.
• FP leads to leukocyte migration and capillary permeability.

Kinin System

• Prekallikrein converts to kallikrein, which converts kininogen to bradykinin.
• Bradykinin increases vascular permeability and causes pain.
• Margination is when leukocytes stick to the vessel wall.
• Diapedesis is when leukocytes leave the vessel to enter tissue.
• Cytokines cause vasodilation via prostaglandin, histamine, and nitric oxide.
• Vascular permeability is increased by histamine, bradykinin, leukotrienes, and PAF.
• Pain is caused by bradykinin and prostaglandin.
• IL-10 and enzymes limit inflammation.

Histamine Effects

• H1 receptors are proinflammatory.
• H2 receptors are anti-inflammatory.
• Cell injury leads to acute inflammation, which either heals, goes to chronic inflammation, produces granulomas then heals.

Chronic Inflammation

• The causes include:
  • Unsuccessful acute inflammation, chemicals
  • Viruses/microorganisms (hiding tactics)
  • Toxins

Wound Healing/Regeneration

• Resolution is when tissue returns to its original function and structure.
• Repair is scar tissue formation, providing structure and strength but not function.

Types of Intention

• Primary intention involves clean/close wounds, sutured incisions and paper cuts.
• Secondary intention involves open wounds that are not closed, resulting in more tissue loss.
• Tertiary intention involves leaving a wound open initially, then closing it later.
• Epithelialization is the process of sealing a wound with epithelial tissue.
• Contraction brings two sides of a wound together, shrinking it.

Phases of Wound Healing

• Hemostasis stops bleeding/clot formation.
• Inflammation involves leukocytes that are present and release cytokines.
• Proliferation involves epithelialization, macrophages clearing debris, clot replacement with normal or scar tissue, and angiogenesis.
• Maturation/Regeneration involves cellular differentiation of epithelial tissue, scar formation, and remodeling.
• Dysfunctional wound healing is caused by ischemia, excess bleeding or fibrin, obesity, diabetes, tobacco use, infection, malnutrition, or drugs.
• A hypertrophic scar is noticeable and raised.
• A keloid is a protruding scar outside of wound boundaries, more common with more melanin.
• Dehiscence is the separation of wound edges.
• Contracture is wound healing that closes together, limiting movement.

Altered Cells and Tissues

• Pathogenesis is the development of disease from stimulus to expression.
• Pathophysiology refers to functional changes accompanying a syndrome/disease.
• Diagnosis is the indication of disease through evaluation of signs/symptoms.
• Etiology is the cause of a disease/origin.
• Idiopathic means there is no known cause.
• Iatrogenic means human-caused, usually in healthcare.
• Predisposing factors encompass tendencies that promote diseases (e.g., lack of physical activity).
• Prophylaxis is a process or measure that prevents disease.
• Acute is sudden/short lived, 8-10 days
• Chronic lasts 2 weeks or longer, recurring/persisting for a long time
• Prevention is linked to etiology and predisposing factors.
• Insidious refers to gradual progression with vague/mild symptoms.
• Subclinical means the disease is present without obvious manifestations.
• Latent is asymptomatic, with no distinct change during incubation.
• Signs are objective findings from assessment, observed/measured.
• Symptoms are subjective, reported or felt by the patient.
• Manifestations are clinical evidence of disease.
• Lesions are specific local changes in tissue (internal or external).
• A syndrome is a constellation of signs/symptoms occurring together under specific conditions.
• Sequelae are unwanted outcomes
• Homeostasis is the tendency to maintain a balanced/constant internal state.
• Stress can lead to adaptation/new state or cell injury/cell death
• Necrosis involves pathologic cell death.
• Apoptosis is programmed cell death.
• Reversible cell damage means the cell can recover.
• Irreversible cell damage means cell death.
• Hypoxia is the lack of oxygen in tissue.
• Ischemia is the lack of blood flow to tissue.
• Infarct is death due to ischemia.
• Ischemia-reperfusion injury involves the formation of free radicals after a lack of blood flow, causing injury.
• ROS (reactive oxygen species) is created from reperfusion of O2.
• Free radicals are unstable oxygen molecules that can damage cells.
• Infiltration is intracellular accumulation.
• Calcium is free-floating and triggers chemical reactions via enzymes, causing low ATP and mitochondrial permeability.

Types of Necrosis

• Coagulative necrosis affects organs dealing with blood like the kidney, protein is denatured, it is associated with ischemia/infarction.
• Liquefactive necrosis affects the CNS, associated with bacterial/fungal or ischemia, hydrolytic enzymes.
• Caseous necrosis is "cheese-like", causes tuberculosis, coagulative and liquefactive, granulomas.
• Gangrenous necrosis can be dry or wet, caused by ischemia superimposed by clostridium perfringens.
• Fat necrosis affects the pancreas/pancreatitis, pancreatic lipase.

Cellular Adaptations

• Atrophy is the shrinking of cell size.
• Hypertrophy is an increase in cell size.
• Hyperplasia is an increase in cell number.
• Metaplasia is a change from one adult cell to another, reversible, which can lead to malignancy.
• Dysplasia is not a true adaptation.

Apoptosis

• Programmed cell death that is
  • Physiological during embryogenesis
  • Pathological due cell injury
• Occurs in 2 pathways:
  • Intrinsic: intracellular proteins favor life vs. death
  • Extrinsic: another cell triggers signals.
• Autophagy is when a cell eats itself to ensure survival when nutrients are scarce.
• Chaperones are proteins that help other proteins fold correctly.
• There are 23 pairs/46 chromosomes, 1-22 autosomal, and 23 are sex chromosomes.
• Histones are any group of basic proteins found in chromatin.
• Chromatin is a complex of DNA and protein.
• Chromosomes are thread-like, made of DNA and protein.
• A gene is a sequence of nucleotides in DNA/RNA.
• A locus is the specific position on a chromosome where a particular gene is located.

Genetics

• Alleles are different versions of a DNA sequence at a genetic.
• A genotype is the genetic makeup of an individual cell/organism.
• A phenotype is the physical expression of genotype and environmental factors.
• Homozygous means 2 same alleles.
• Heterozygous means 2 different alleles.
• A dominant gene only requires one allele to express phenotype.
• A recessive gene often masked and requires 2 alleles to express.
• Codominance means both traits are expressed.
• A carrier possesses the defective gene.
• The centromere is what attaches during cell division.
• The short arm is the p, top half of a chromosome.
• The long arm is the q, bottom half of a chromosome.
• Chromosomal aberrations are entire chromosome defects.
• A single gene disorder means a specific gene is affected.
• Multifactorial involving genes and the environment.
• Euploidy is 23 pairs of chromosomes.
• Aneuploidy refers to abnormal chromosome numbers.
• Trisomy is 3 chromosomes
• Monosomy is 1 chromosome.
• Nondisjunction causes aneuploidy.
• Autosomal Aneuploidy is Trisomy 21/Down Syndrome
• Sex Chromosome Aneuploidy can cause Turner Syndrome or Klinefelter's Syndrome.
• Trisomy 21 is more likely in mothers over the age of 35
• Turner Syndrome occurs in females with one X chromosome.
• Klinefelter's Syndrome that is XXY or XXXY more x's more problems

Pedigree Tables

• Used to study genetic disorders within a family
• Single Gene Disease:
  • Autosomal recessive: 2 defective genes
  • Autosomal dominant: 1 defective gene
  • X-linked recessive: more prominent in males
• Recurrence risk: probability that an individual will develop a genetic disease
• Penetrance: probability of the gene being expressed
• Expression: phenotypic
• Autosomal Dominant: delayed lethal phenotype
  • Ex: Huntington's Disease
• Autosomal Recessive:
  • Ex: Cystic Fibrosis
• X-linked Recessive Inheritance: males affected
  • Ex: Hemophilia
• Multifactorial: genetic and environment
• Tests: preconception
  • Recommended, woman over 35
• Alpha-fetoprotein in babies can indicate down syndrome

Cancer

• Cancer: disease on which abnormal divide w/o control and can invade other tissue
• Neoplasia: abnormal growth of cells/tissues in body
• Genetic: DNA mutation
• Heritable: Darwin Selection
• Benign: Not cancerous and slow growing
• Malignant: cancerous and fast growing
• Proto-oncogenes: normal cell proliferation
• Oncogenes: cancerous, cell proliferation
• Tumor-suppressor: stop cell division prevent mutation,
  • Ex: Damage gene
• Cancerous cells need limitless division
• Angiogenesis: new blood vessels
• VEGF: nutrients
• Warburg effect is when cancer in limited by cell division
• Manifestations: wasting away
• Diagnostics, a routine screening is key
• TNM: Tumor Nodes Metastasis,
  • Ex: t0=no tumor
• Staging: where cancer has spread, -Ex Stage 1: confined to origin
• Grading: what cells look like/behavior -Grade 1: well differentiated
• Cancer is 25% of deaths, 40% preventable
• Morbidity: symptoms of a disease
• Mortality: death
• Diagnosed: breast: colorectal
• Deaths: lung, breast, colorectal
• Fat supports growth of cancer

Test your knowledge of cancer biology with this quiz. Questions cover tumor characteristics, angiogenesis, cancer staging, the Warburg effect, oncogenes, viral associations, and immunotherapy.