Molecular analysis of human papillomavirus high risk genotypes and it s association with Selected oncogenes of cervical cancer

Abstract

newlineCervical cancer (CC) is the most common malignancy in women. It is the second most cause of cancer related deaths in women and one of the leading causes of mortality in Indian women. It is a complex disease that involves Human Papilloma Virus (HPV) infection followed by the accumulation of both genetic, epigenetic alterations of genes, activity of oncogenes, life style factors and personal habits. The genetic variations in oncogenes associated with cervical cancer in our study population needs to be extensively characterized. In this study, the subjects were recruited from the Department of Obstetrics and Gynaecology, Chettinad Hospital and Research Institute, Chettinad Super Speciality Hospital, Kelambakkam and Madurai Rajaji Hospital, Madurai. An informed consent and a detailed questionnaire were taken from each participant of the study. The Genomic DNA isolated from cervical scrapings were used to screen HPV high risk genotypes using type specific polymerase chain reaction. Molecular simulation was performed using GROMACS software to determine the structural differences of E6 oncoprotein among HPV16 and 18 genotypes. Gene specific PCR was performed to identify the variations in selected oncogenes (PIK3CA, KRAS and PTEN) associated with cervical malignancy and finally the variations were confirmed by Bidirectional DNA sequencing. The results of HPV positivity was 10.47% in controls, 60.86% in low-grade squamous intraepithelial lesions, 79.24% in high-grade squamous intraepithelial lesions and 87.80% among cervical cancer subjects. Molecular modeling of E6 oncoprotein revealed structural differences between HPV16 and 18 which may be associated with their oncogenic nature. The mutational frequency of analyzed oncogenes was as follows; PIK3CA (16.66%), KRAS (6.37%) and PTEN (2.45%). The detection of HPV genotypes will serve as baseline data in implicating the future vaccination programmes. Based on our mutation frequencies in the oncogenes associated with CC, they can be incorpora