HPV52 E6和E7基因多态性与宫颈上皮内瘤变相关性

RELATIONSHIP BETWEEN E6 AND E7 GENE POLYMORPHISMS OF HUMAN PAPILLOMAVIRUS TYPE 52 AND CERVICAL INTRAEPITHELIAL NEOPLASIA

目的探讨人乳头瘤病毒52型(HPV52)E6和E7基因多态性与宫颈上皮内瘤变(CIN)的相关性。方法收集来自青岛地区的177例HPV52阳性且进行宫颈活检病人的宫颈脱落细胞样本,采用PCR直接测序法检测E6和E7基因序列,在GenBank中剪切HPV52标准株和变异株序列,应用Lasergene和MEGA软件对序列进行比对和系统进化树分析。比较正常、低级别上皮内瘤变(CIN1)和高级别上皮内瘤变(CIN2/3)样本中E6和E7基因变异型的分布。结果138例样本成功获得E6和E7基因序列。与标准株比较,132例(95.7%)样本在E6区同时出现1处错义突变(K93R)和1处同义突变(g350t),经系统进化树分析,确定为B变异型;其余样本有5例(3.6%)属于A变异型,1例(0.7%)属于C变异型。135例(97.8%)样本在E7区同时出现2处同义突变(c751t和a801g),为B变异型;其余样本有2例(1.5%)属于A变异型,1例(0.7%)属于C变异型。正常、CIN1和CIN2/3样本之间E6和E7变异型的分布差异均无显著性(P>0.05)。结论来自青岛地区正常及CIN样本中HPV52 E6和E7基因均以亚洲株B变异型为主,E6和E7基因多态性可能与CIN发生发展无明显相关性。

Objective To explore the relationship between the E6 and E7 gene polymorphisms of human papillomavirus type 52(HPV52)and cervical intraepithelial neoplasia(CIN).Methods We collected the cervical exfoliated cell samples from 177 patients who were positive for HPV52 and underwent cervical biopsy in Qingdao,China.The E6 and E7 gene sequences of the samples were determined by PCR-based direct sequencing.With the sequences of standard and variant HPV52 strains obtained from GenBank,sequence alignment and phylogenetic analysis were carried out using Lasergene and MEGA software.The distributions of E6 and E7 variants were compared between normal,low-grade intraepithelial neoplasia(CIN1),and high-grade intraepithelial neoplasia(CIN2/3)samples.Results The E6 and E7 sequences of 138 samples were obtained.Compared with the standard strain,132(95.7%)samples had a missense mutation(K93R)and a synonymous mutation(g350t)both in the E6 region,belonging to lineage B variant as demonstrated by the phylogenetic tree;in addition,5(3.6%)and 1(0.7%)samples belonged to lineage A and C variants,respectively.One hundred and thirty-five(97.8%)samples had two synonymous mutations(c751t and a801g)both in the E7 region,belonging to lineage B variant;2(1.5%)and 1(0.7%)samples belonged to lineage A and C variants,respectively.There were no significant differences in the distributions of E6 and E7 variants between normal,CIN1,and CIN2/3 samples(P>0.05).Conclusion The HPV52 E6 and E7 variants in normal and CIN samples from Qingdao predominantly belong to Asian lineage B.E6 and E7 gene polymorphisms may not be related to the development of CIN.