title: The prevalence of HPV-18 and variants of E6 gene isolated from cervical cancer patients in Taiwan.
abstract: BACKGROUND
  Cervical cancer is the second most common cancer in women worldwide. It has been considered that human papillomavirus (HPV) is associated with cervical cancer. Currently, more than 80 different serotypes of HPV have been characterized and they are divided into low- and high-risk groups. The most common types that lead to cervical cancer are HPV-16 and -18. The viral oncogenes E6 and E7 are associated with the development of cervical cancer. In previous study, the variants of HPV-16 E6 gene have been reported. It suggests that variants may influence the morbidity of carcinogenesis, but the variant study on HPV-18 remains unknown.
  
  
  OBJECTIVE
  To identify the variants of integrated HPV-18 E6 gene in the prevalent infection of HPV-18 of cervical cancer patients.
  
  
  METHODS
  25 cervical cancer patients were clinically identified and the biopsies were obtained. The infectious HPV types were identified by PCR and Southern blotting analysis. The DNA fragments of the integrated HPV-18 E6 were amplified by PCR and cloned. The nucleotide sequences were obtained by sequencing.
  
  
  RESULTS
  The prevalence of HPV infection in our 25 cases was HPV-18 (100%) and 7 out of these 25 cases (28%) were co-infected with HPV-16. The most dominant mutation among 25 tested patients was a silence mutation C183G of the E6 coding region.
  
  
  CONCLUSIONS
  The prevalent HPV infectious serotype is HPV-18, which differs from the worldwide prevalent type. The identified HPV-18 E6 variants had a unique silence mutation located on C183G in E6 coding region.
authors.affiliation: Department of Life Science, Tunghai University, 181, Sec. 3, Chungkang Rd., Taichung, Taiwan, ROC.
authors.forename: Chih-Hsiang
authors.initials: CH
authors.lastname: Chang
authors.forename: Tze-Ho
authors.initials: TH
authors.lastname: Chen
authors.forename: Reuy-Chang
authors.initials: RC
authors.lastname: Hsu
authors.forename: Pan-Hsin
authors.initials: PH
authors.lastname: Chou
authors.forename: Jaw-Ji
authors.initials: JJ
authors.lastname: Yang
authors.forename: Guang-Yuh
authors.initials: GY
authors.lastname: Hwang
mesh_terms: D000328:Adult; D002294:Carcinoma, Squamous Cell / Q000737:chemistry / Q000453:epidemiology / Q000821:virology*; D005260:Female; D006801:Humans; D009856:Oncogene Proteins, Viral / Q000235:genetics*; D027383:Papillomaviridae / Q000235:genetics* / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000453:epidemiology*; D015995:Prevalence; D012097:Repressor Proteins / Q000235:genetics*; D013624:Taiwan / Q000453:epidemiology; D002583:Uterine Cervical Neoplasms / Q000737:chemistry / Q000453:epidemiology / Q000821:virology*
chemical_list: C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D012097:Repressor Proteins