Variations of human papillomavirus type 58 E6, E7, L1 genes and long control region in strains from women with cervical lesions in Liaoning province, China

Abstract

Infection with certain types of human papillomaviruses (HPVs) is a risk factor for the development of cervical cancer. HPV type 58 (HPV 58) is prevalent among Chinese women. The intratype sequence variants differ in oncogenic potential and their prevalences vary across geographic regions. The objective of this study was to analyze the variations of HPV 58 E6, E7, L1 genes and long control region (LCR) in a large samples collected from northeastern Chinese women with cervical lesions. A total of 2938 cervical samples were collected and tested for HPV type using a chip hybridization assay. The E6, E7, L1 genes and LCR of HPV 58 strains were amplified and the amplicons were subjected to direct nucleotide sequencing for variation identification. A total of 235 specimens were HPV 58 positive. High proportions of HPV 58 E6 (83.8%), E7 (76.7%), L1 (90.8%) genes and LCR (91.4%) variants were identified in strains from Chinese women. The most frequently observed variations were C307T (52.4%) in E6, T744G (74.9%) in E7, A6014C (56.9%) in L1 genes and C7266T, A7714G (55.2%) in LCR. For the E6 gene, nine nucleotide variations were identified. Among them, the A140G (T11A), A184C (E25D), G266C (V53L) and A313G were novel variations. Sequencing of the E7 gene revealed four typical nucleotide changes: G761A (G63D), G694A (G41R), T803C (V77A) and T744G. In the L1 gene, 39 nucleotide variations and 13 amino acid substitutions were identified. Among these mutations, 21 variations are reported here for the first time. Lineage A of HPV 58 was found in 142 of 174 strains (81.6%). The most prevalent HPV 58 variants in Chinese northeastern women belongs to lineage A. Novel variations in E6 and L1 genes were also reported. These findings provide new data regarding E6 and L1 gene variations of HPV 58 from women in northeast China.