Which of the Following is the Best Example of a Tumor-Suppressor

Question

Which of the following is the best example of a tumor-suppressor gene?
A) The RB gene involved in retinoblastoma
B) Philadelphia chromosome in chronic myelogenous leukemia
C) C- ras involved in human bladder cancer
D) C-myc involved in Burkitt's lymphoma.
E) Platelet-derived growth factor (PDGF)

Accepted Answer

Tumor-suppressor genes are genes that inhibit cell cycle progression and prevent the formation of tumors. The RB gene is a well-known example of a tumor-suppressor gene. Mutations in the RB gene can lead to the development of retinoblastoma, a type of eye cancer. The other choices listed are not tumor-suppressor genes. The Philadelphia chromosome (B) is a chromosomal abnormality that is found in chronic myelogenous leukemia. C-ras (C) and C-myc (D) are oncogenes that promote tumor growth when mutated. Platelet-derived growth factor (PDGF) (E) is a growth factor that stimulates cell proliferation, but it is not a tumor-suppressor gene.