Oncogenic Viruses

Question 1

What is the function of tumor suppressor genes?

Answer 1

They regulate cell division and death, thus preventing the development of cancer.

Question 2

Name a key tumor suppressor gene.

Answer 2

p53

Question 3

Differentiate proto-oncogenes and tumor suppressor genes and give examples of each.

Answer 3

🩺 Proto-oncogenes are genes that promote cell growth, division and differentiation. They encode proteins that help regulate cell proliferation and survival.
Examples: RAS, MYC and HER2.

🩺 Tumor suppressor genes are genes that help regulate cell growth and division by inhibiting cell proliferation and promoting apoptosis.
Examples: RB1, TP53, BRCA1.

Question 4

Name the seven known oncoviruses and their associated malignancies.

Answer 4

(1) Hepatitis C Virus (HCV): Hepatocellular carcinoma
(2) Hepatitis B virus: Hepatocellular carcinoma
(3) Human Papillomavirus (HPV): Cervical cancer, oropharyngeal cancers, anal/genital cancers
(4) Epstein-Barr Virus (EBV): Burkitt’s lymphoma, Hodgkin lymphoma, nasopharyngeal carcinoma
(5) Kaposi’s Sarcoma-associated Herpesvirus (HHV-8): Kaposi’s sarcoma
(6) Human T-lymphotropic virus-1 (HTLV-1): Adult T-cell leukemia/lymphoma
(7) Merkel Cell Polyomavirus: Merkel cell carcinoma