E6, E7 genes of which virus are implicated in oncogenesis ?
## **Core Concept**
The question pertains to the oncogenic properties of certain viral genes, specifically E6 and E7, which are associated with the development of cancer. These genes are known to be part of the genome of certain viruses that can lead to malignant transformations in host cells. The viruses in question are typically DNA viruses.
## **Why the Correct Answer is Right**
The correct answer, **Human Papillomavirus (HPV)**, is implicated in oncogenesis through its E6 and E7 genes. These genes encode proteins that can bind to and inactivate tumor suppressor proteins p53 and Rb (retinoblastoma protein), respectively. The inactivation of p53 and Rb leads to uncontrolled cell division and is a critical step in the development of cancer, particularly cervical cancer. HPV is well-documented to cause cervical cancer, and the E6 and E7 genes are consistently expressed in cervical carcinoma cells.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not provided, but if it were a different virus, the explanation would focus on why that virus is not primarily associated with E6 and E7 genes in oncogenesis.
- **Option B:** Similarly, without the specific content of Option B, we can infer that any incorrect option would not have a well-established link between its E6 and E7 genes and oncogenesis comparable to HPV.
- **Option C:** Again, without specifics, the reasoning would involve explaining why the viruses listed in these options do not have the same level of evidence linking their E6 and E7 genes to cancer development as HPV does.
- **Option D:** This option is also not provided, but presumably, it would be incorrect for similar reasons as Options A, B, and C.
## **Clinical Pearl / High-Yield Fact**
A crucial point to remember is that **HPV types 16 and 18** are high-risk strains that are most commonly associated with cervical cancer and other anogenital cancers. The E6 and E7 genes from these strains are particularly efficient at disrupting cell cycle regulation. Vaccines targeting HPV have been developed to prevent infection by these high-risk strains, offering a preventive measure against certain types of cancer.
## **Correct Answer:** B. Human Papillomavirus (HPV).