Physical Carcinogens and Proto-oncogenes Quiz
22 Questions
5 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the term used to describe the ability to notice distinct characteristics of cancer cells from other surrounding tissues?

  • Malignancy
  • Differentiation (correct)
  • Metastasis
  • Benignity
  • Which type of cancer originates from melanocytes?

  • Leukemia
  • Sarcoma
  • Melanoma (correct)
  • Lymphoma
  • What occurs when a damaged DNA cannot be repaired in normal cells exposed to mutagens?

  • Benign transformation
  • Inhibition of Apoptosis
  • Mutation (correct)
  • Activation of Tumor Suppressor Genes
  • Which class of substances are alkylating agents and aromatic hydrocarbons examples of?

    <p>Mutagens</p> Signup and view all the answers

    What is the main consequence of the inhibition of apoptosis in carcinoma cells?

    <p>Cells divide uncontrollably</p> Signup and view all the answers

    In carcinogenesis, what do mutagens lead to after damaging the DNA in normal cells?

    <p>Activation of Oncogenes</p> Signup and view all the answers

    What is a characteristic of an ideal tumor marker?

    <p>High sensitivity</p> Signup and view all the answers

    Which of the following is NOT a way to promote apoptosis in cancer cells?

    <p>Increasing DNA repair mechanisms</p> Signup and view all the answers

    Which genetic mutation can lead to uncontrolled cell division?

    <p>Insertion of promoter</p> Signup and view all the answers

    Which chemical compound is known to cause Hepatic Carcinoma?

    <p>Aflatoxin B1</p> Signup and view all the answers

    Which virus is associated with causing Kaposi’s sarcoma?

    <p>Epstein-Barr Virus (EBV)</p> Signup and view all the answers

    How do ideal tumor markers respond to treatment?

    <p>Decreased levels</p> Signup and view all the answers

    Which type of genes are responsible for slowing down cell division, repairing DNA mutations, and promoting apoptosis?

    <p>Tumor suppressor genes</p> Signup and view all the answers

    What is the primary function of tumor suppressor genes when they are not mutated?

    <p>Inhibit cell division</p> Signup and view all the answers

    Which type of mutation results in a loss or reduction in the function of tumor suppressor genes?

    <p>Point mutation</p> Signup and view all the answers

    What is the role of proto-oncogenes in normal cells?

    <p>Promote cell division</p> Signup and view all the answers

    What type of gene conversion can result in proto-oncogenes becoming oncogenes?

    <p>Point mutation</p> Signup and view all the answers

    Which characteristic is NOT commonly associated with an ideal tumor marker?

    <p>Relatively long half-life</p> Signup and view all the answers

    What is a key feature of tumor markers that are produced by the body in response to tumor cells?

    <p>Presence in plasma and body fluids</p> Signup and view all the answers

    What is the primary purpose of utilizing tumor markers in cancer diagnosis?

    <p>To support diagnosis as a laboratory test</p> Signup and view all the answers

    What does the inhibition of tumor suppressor genes primarily result in?

    <p>Promotion of cell division</p> Signup and view all the answers

    What is the consequence of mutations in proto-oncogenes that convert them into oncogenes?

    <p>Growth and division of cells</p> Signup and view all the answers

    Study Notes

    Physical Carcinogens

    • X-ray, Gamma ray, and UV ray can cause:
      • Formation of pyrimidine dimers
      • Apurinic sites with consequent break in DNA
      • Formation of free radicals and superoxides leading to DNA break and somatic mutations
      • Increase risk of leukemia in childhood if exposed during fetal life

    Proto-Oncogenes and Oncogenes

    • Proto-oncogenes are responsible for the synthesis of:
      • Growth factors
      • Transcription factors
      • Receptor factors
      • Proteins for gene expression
    • Proto-oncogenes can be converted to oncogenes through:
      • Point mutation
      • Chromosomal translocation
      • Gene amplification
    • Examples of oncogenes:
      • jun (Transcription Factor)
      • fos (Transcription Factor)
      • myc (DNA Binding Protein)
      • ras (GTPase)
      • rat (Protein Kinase)
      • abl (Tyrosine Kinase)
      • sis (Platelet-Derived Growth Factor)

    Tumor Suppressor Genes (Anti-Oncogenes/Recessive Oncogenes)

    • Normal genes that:
      • Slow down cell division
      • Repair DNA mutations
      • Responsible for apoptosis
    • Mutation can result in loss or reduction of function, allowing cells to grow abnormally and cause cancer
    • Examples of tumor suppressor genes:
      • RB1 (Retinoblastoma Gene 1)
      • P53 (Phosphoprotein)
      • WT (Wilm's Tumor)
      • FAP (Familial Adenomatous Polyposis)
      • BRCA (Breast cancer gene)

    Tumor Markers

    • Biochemical indicators of the presence of a tumor
    • Produced by tumor cells (tumor-derived) or by the body in response to tumor cells (tumor-associated)
    • Detected in plasma and body fluids such as urine, CSF, and pleural fluid
    • Characteristics of an ideal tumor marker:
      • Specific production in premalignant or malignant tissue
      • Early in the progression of disease
      • Sensitive and produced at detectable levels in all patients with a specific malignancy
      • Expression in an organ site-specific manner
      • Evidence of presence in bodily fluids obtained non-invasively
      • Levels related quantitatively to tumor volume, biological behavior, and disease progression
      • Relatively short half-life, reflecting temporal changes in tumor burden and response to therapy

    Cancer

    • Types of cancer classified by origin:
      • Epithelial (Carcinoma)
      • Blood cells (Leukemia)
      • Lymphatics (Lymphoma)
      • Connective Tissue (Sarcoma)
      • Melanocyte (Melanoma)

    Carcinogenesis

    • Normal cells exposed to chemicals, viruses, or radiation can damage DNA
    • Damaged DNA can be repaired, but failure to repair leads to mutation
    • Mutation can lead to:
      • Activation of oncogenes
      • Inhibition of tumor suppressor genes
      • Inhibition of apoptosis

    Etiology (Mutagens)

    • Substances that increase the rate of mutation, enhancing the incidence of cancer
    • Examples of mutagens:
      • Chemicals:
        • Alkylating Agents
        • Aromatic Hydrocarbons
        • Aromatic Amines
        • Nitroso Compounds
      • Viruses:
        • HPV (human papillomavirus)
        • HSV (herpes simplex virus)
        • HBV (hepatitis B virus)
        • HCV (hepatitis C virus)
        • HIV (human immunodeficiency virus)
        • HTLV (human T-lymphotropic virus type 1)
        • EBV (Epstein-Barr Virus)

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Test your knowledge on the effects of physical carcinogens like X-ray, Gamma ray, and UV ray on DNA, as well as the role of mutations in proto-oncogenes transforming into oncogenes. Learn about the mechanisms through which these factors contribute to cancer development.

    More Like This

    Use Quizgecko on...
    Browser
    Browser