| ObjectiveHuman papillomavirus type 16 (HPV16) has a number of intratypic variants; each has a different geographical distribution and some are associated with enhanced oncogenic potential. This study was performed to identify sequence variants in the HPV 16 transforming gene E7 and E5 derived from Qingdao women with cervical and noncancerous lesions, and to assess the association between the sequence variant and the cervical lesions.Materials and Methods[1] 420 cervical cases consisted of 180 low-grade squamous intraepithelial lesions, 120 high-grde squamous intraepithelial lesions and 120 invasive cervical carcinoma. By histopathologic examination,264 case biopsies were graded as normal cervical tissues(n=59), cervical intraepithelial neoplasia grade 1(CIN 1, n=8), cervical intraepithelial neoplasia grade 2 (CIN 2, n=15), cervical intraepithelial neoplasia grade 3 (CIN 3, n=62), or invasive cervical carcinoma(ICC, n=120) according to the highest grade present within a lesion.[2] DNA samples were extracted from the cervical scrapes and tissues.[3] DNA samples were amplified by polymerase chain reaction(PCR) using specific primers for high-risk HPV, HPV16 to identify the positive tissues.[4] DNA samples extracted from the HPV16 positive tissues were amplified by the primers for E7 and E5.[5]Then the PCR fragments of HPV16 E7 and E5 genes were purified, sequenced and compared with the type stain.Results[1] The positive rate of HPV16 was 19.44%(35of 180) for LSIL,45.83%(55 of 120) for HSIL,28.36%(19 of 67) for=CINI,36.36%(28 of 77) for CIN2/3 and 60% (80of 120) for patients with cervical cancer.[2] The most frequent HPV 16 branch was type AS(51.52%), followed by type E (48.48%). It was found that As-positive cervical cancer patients were 10 years younger than E-positive ones.[3] 65 cases of ICC,28 cases of LSIL,39 cases of HSIL,24 cases of CIN2/3 and 14 cases of=CIN1 were analysed for HPV16 E7 sequence variation.Seven variants of the HPV 16 E7 gene were identified. The A647G(N29S) is the prevalent variant in all analyzed different disease stages being present in,42.86% of LSIL,51.28% of HSIL, 64.29% of CINI,54.17% of CIN2/3 and 60% of ICC.[4] 22 cases of LSIL,25 cases of HSIL,8 cases of=CIN1,18 cases of CIN2/3 and 17 cases of ICC were analysed for HPV 16 E5 sequence variation.5 variants were identified and only 2 showed an amino acid change. The most frequent E5 variation was A4042G (165V) in combination with A3979C (I44L) and A4077T(nonsense mutation). The prevalence of A3979C,A4042G and A4077T was 68.18%915/22) in LSIL,52% (13/25) in HSIL,75%(6/8) in=CIN1 cases,61.11%(11/18) in cervical intraepithelial neoplasia grade 2/3 cases and 58.82%(10/17) in invasive cervical carcinoma cases.Conclusions[1] HPV16 is associated with the progression of cervical cancer.[2] HPV16AS lineage is predominant in Qingdao. As lineage appeares to be more oncogenic than E lineage.[3] The A647G(N29S) is the prevalent variant in Qingdao cervical cancer cases. The results do not show any importance of E7 variants for ICC progression in Qingdao women.[4] 3979th,4042th and 4077th nucleotide in E5 gene is the very important site to distinguish the Asia and the Europe prototype strain. |
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