Polymorphism in the E6 gene of human papillomavirus type 16 in the cervical tissues of Korean women.

The aim of this study was to identify sequence variants in the HPV 16 E6 gene in Korean women and to examine the possible association between these sequence variants and cervical cancer development. We examined the HPV 16 DNA of 215 patients with no cervical disease (NCD) (n = 105) or with cervical neoplasia (n = 110) [cervical intraepithelial neoplasia (CIN), n = 61; invasive cervical carcinoma (ICC), n = 49] using the nested polymerase chain reaction (PCR) and PCR-directed sequencing methods. Fifty-four (NCD, n = 10; CIN, n = 17; ICC, n = 27) of the 215 samples contained HPV 16 E6 DNA, but only two (7.4%) of 27 ICC samples had prototype sequences. The most frequently found variation was D25E (in NCD, n = 8, 80%; in CIN, n = 9, 52.9%; in ICC, n = 23, 85.2%). This is a rare variation in western countries. No significance difference was found between the frequencies of D25E variation in cancerous and non-cancerous lesions. Among the 11 kinds of variants identified, four variants were novel and have been registered with GenBank. This study demonstrates that the D25 variant is the most prevalent E6 genomic variant type in Korean population. However, it was not found to be associated with an increased risk of ICC.