To determine the expression of E6 and E7 in precancerous and cancerous lesions of cervix by using Immuno-histochemistry: An Observational Study.

In India, cervical cancer ranks as the second most common malignancy among women overall

and among those between the ages of 15 and 44. Approximately 5.0% of women in the general

population are infected with HPV-16/18 at any given moment, and HPV s 16 or 18 are the cause

of 83.2% of invasive cervical malignancies. (1). Persistent high-risk genital HPV infection

accounts for approximately 99.7% of cases of cervical cancer. (2)

Yamato et al., 2008; Jabbar et al., 2009 stated that HPV E6 and E7 viral oncoproteins play the

important role in oncogenesis. During the process of replicating the viral genome induce all the

hallmarks of a cancer cell like uncontrolled cellular proliferation, angiogenesis, invasion, metastasis, and unrestricted telomerase activity and evasion of apoptosis and growth suppressors’ activity. E6 degrade p53 through ubiquitination and cause continuous cell proliferation. In

normal cells RB plays important role in regulating the G1-S checkpoint of the cell cycle. In HPV

infected cells the E7 targets the Rb phosphorylation by cyclin D-CDK4, cyclin D-CDK6 leading

to the release of E2F transcription factor. Then the latter activates transcription of S-phase genes

forcing the cells through premature S phase entry. E7 also triggers the expression of

p16(CDKN2A) through RB disintegration and also epigenetic derepression through KDM6B.P16 normally acts as tumor suppressor gene but in HPV infected cells it exhibits oncogenetic activity. But p16 is not exclusively increased in cervical carcinoma, it is increased in wide variety of tumors such as pancreatic, esophageal and head neck carcinoma. So, p16 alone cannot be used as it is nonspecific .Other less invasive methods for screening for cervical cancer include liquid-based cytology and RTPCR. In affluent nations, cervical cancer cases can be effectively controlled with these cytological screening techniques. But these kinds of screening systems are not practical in middle-class or lower-class nations like India. RTPCR and LBC equipment accessibility and a shortage of qualified professionals are obstacles that impact cytological screening programs. So, E6 and E7 expression on immunohistochemistry is a better option. There are proven studies of E6 and E7 expression on head and neck squamous cell carcinoma and oropharyngeal carcinoma caused by HPV and very few on cervical carcinoma. No study could be retrieved from the literature on E6 and E7 protein in cervical carcinoma cases using IHC in India.