Since HPV infection is associated with cervical cancer, you obtain a HPV-infecte
ID: 282629 • Letter: S
Question
Since HPV infection is associated with cervical cancer, you obtain a HPV-infected cancer cell line and a corresponding uninfected normal cell line from a patient. You determine that there is no p53 protein in the infected cancer cells, although the RNA is expressed normally.
When you infect the normal cell line with HPV, you find that the p53 protein levels drop dramatically, yet the p5 RNA levels remain the same. Which of the following could explain how HPV might be involved in cervical cancer.
1)HPV causes the degradation of the p53 protein.
2)HPV codes for an oncogene that is expresses at high levels
3)HPV integrates into p53 locus, thereby knocking out the p53 gene
4)HPV promotes tumorigenisis by suppressing the immune system of the infected patient
5)HPV codes for a protein that degrades a DNA repair protein, leading to mutations in the p53 gene
6)HPV encodes a p53 gene to be expressed at high levels
Explanation / Answer
Option first is the correct answer. p53 is tumor suppressor protein encoded by p53 gene. Lack of p53 gene may results into cancer. HPV (human papilloma virus) contain two early gene E6 and E7. These act as transforming gene. E6 protein binds with p53 protein and promotes the degradation of the tumor suppressor protein p53. E7 protein forms a` complexes with the Rb protein and inactivates it; together, they disrupt cell cycle regulation which may result in cancer.