Human Papillomavirus 16 (HPV16) and itûs E2 Polymorphisms

The E2 protein of HPV is the viral factor that binds to the specific sites on long control region of the viral genome to regulate genome replication and transcription of the viral oncogenes, E6 and E7. To determine the polymorphisms in the E2 DNA sequence and amino acid change in HPV16 episomal form, this study amplified and sequenced the E2 gene of HPV16 episomal form that selected from 241 paraffin-embedded tissues with HSIL and SCC. Results showed 91.70 % of samples were positive for HPV DNA and HPV16 was the most common, 77.68 % in HSIL and 85.83 % in SCC. 13 of 40 positive HPV16 cases were found containing E2 episomal form that were classified mostly into As variant. Nucleotide and amino acid changes were demonstrated in 5 cases and mostly found in TAD of both HPV16 AA and As variant. These results suggested that polymorphisms of E2 protein may impair the transcriptional regulation of vial oncogenes that induce malignant transformation of HPV infected cell in episomal form