Cervical Cancer

Cervical cancer is mainly caused by human papilloma viruses (HPV), which are a group of more than 100 viruses. Type 16 and type 18 are the high-risk HPVs for cervical cancer. About 70% of cervical cancer patients are infected with HPV 16 or 18.

The genomes of HPV 16 and HPV 18 encode two proteins, E6 and E7, which can inactivate two crucial proteins involved in cell cycle control: p53 and pRB. The E7 protein can bind directly with pRB and inactivate its function. The E6 protein does not associate with p53 directly. Rather, it forms a complex with a cellular protein called E6-AP. The complex can induce degradation of p53 through ubiquitination.

The E6 protein can also induce telomerase activity. High level of telomerase activity is a characteristic of cancer cells since telomerase is required for a large number of cell divisions.

Other genes involved in cervical cancer: KAI1 (reference), PTEN (reference), and ST3.

Review Article:

Mechanisms of Human Papillomavirus-Induced Oncogenesis - J. Virology, 2004.