宫颈癌患者人巨细胞病毒临床分离株基因序列遗传变异分析

Analysis of the genetic variation of HCMV strains clinically isolated from patients with cervical cancer

目的通过对宫颈癌患者人巨细胞病毒（HCMV）临床分离株基因序列遗传变异分析,了解其与宫颈癌之间的相关性,从而为宫颈癌发病机制研究提供理论依据。方法从宫颈癌患者的细胞标本中分离HCMV,对其基因进行全长序列PCR扩增,并进行同源性比较。结果 PCR扩增HCMV基因全长序列分别为568、347、1 472、466和732bp;测序分析5个基因的突变均由碱基替换所引起,并且UL83基因第18、231位氨基酸的突变位点都是具有诱导CTL抗原决定簇反应能力的表位区,而UL32,UL44,UL137和UL145基因序列具有高度保守性,初步推测UL83基因CTL表位突变情况可能与宫颈癌患者HCMV感染有关联;同源性比较显示,HCMV基因与HCMV AD169株、Merlin株、Towne株同源性为97%-100%。结论 UL83基因的突变可能是导致HCMV感染的主要原因,且其第18、231位氨基酸的突变位点都是具有诱导CTL抗原决定簇反应能力的表位区,因此认为UL83基因CTL表位突变可能与宫颈癌患者HCMV感染有关联。

Objective To ascertain the correlation between human cytomegalovirus（HCMV）and cervical carcinoma by analyzing genetic variation in the gene sequences of HCMV strains clinically isolated from patients with cervical cancer in order to provide a theoretical basis for the pathogenesis of cervical carcinoma. Methods HCMV was clinically isolated from cell specimens from patients with cervical carcinoma,and then the full-length sequence of the UL32,UL44,UL83,UL137,and UL145 genes was amplified using PCR.The homology of these genes was compared. Results Amplifying the full-length sequence of the UL32,UL44,UL83,UL137,and UL145 genes using PCR revealed that clinical isolates of HCMV produced bright specific bands that were 568 bp,347bp,1,472 bp,466bp,and 732 bp in length.Mutations in the 5genes were all caused by base substitutions,and mutations of the amino acids at positions 18 and 231in the UL83 gene were both in epitope regions with the potential to induce the reactivity of CTL epitopes.UL137 and UL145gene sequences were highly conserved.Thus,speculation was that mutations in CTL epitopes of the UL183 gene might be associated with HCMV infection in patients with urothelial carcinoma.The UL83 gene of the clinical isolates of HCMV was homologous and its similarity to the same gene in the AD169,Merlin,and Towne strains of HCMV was 97%-100%.Conclusion Mutations in the UL83 gene might be the main reason why HCMV infection occurs.Mutations in the amino acids at positions 18 and 231in the UL83 gene were both in epitope regions,potentially inducing the reactivity of CTL epitopes.Thus,mutations in CTL epitopes of the UL183 gene might be associated with HCMV infection in patients with cervical carcinoma.