title: E6 and E7 variants of human papillomavirus-16 and -52 in Japan, the Philippines, and Vietnam.
abstract: Human papillomavirus (HPV) has several intragenotypic variants with different geographical and ethnic distributions. This study aimed to elucidate the distribution patterns of E6 and E7 (E6/E7) intragenotypic variants of HPV type 16 (HPV-16), which is most common worldwide, and HPV-52, which is common in Asian countries such as Japan, the Philippines, and Vietnam. In previous studies, genomic DNA samples extracted from cervical swabs were collected from female sex workers in these three countries and found to be positive for HPV-16 or HPV-52. Samples were amplified further for their E6/E7 genes using type-specific primers and analyzed genetically. Seventy-nine HPV-16 E6/E7 genes were analyzed successfully and grouped into three lineages: European (Prototype), European (Asian), and African-2. The prevalences of HPV-16 European (Prototype)/European (Asian) lineages were 19.4%/80.6% (n = 31) in Japan, 75.0%/20.8% (n = 24) in the Philippines, and 0%/95.8% (n = 24) in Vietnam. The 109 HPV-52 E6/E7 genes analyzed successfully were grouped into four lineages, A-D; the prevalences of lineages A/B/C/D were, respectively, 5.1%/92.3%/0%/2.6% in Japan (n = 39), 34.4%/62.5%/0%/3.1% in the Philippines (n = 32), and 15.8%/73.7%/7.9%/2.6% in Vietnam (n = 38). The distribution patterns of HPV-16 and HPV-52 lineages in these countries differed significantly (P < 0.000001 and P = 0.0048, respectively). There was no significant relationship between abnormal cervical cytology and either HPV-16 E6/E7 lineages or specific amino acid mutations, such as E6 D25E, E6 L83V, and E7 N29S. Analysis of HPV-16 and HPV-52 E6/E7 genes can be a useful molecular-epidemiological tool to distinguish geographical diffusion routes of these HPV types in Asia.
authors.affiliation: Department of Viral Infection and International Health, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors.forename: Azumi
authors.initials: A
authors.lastname: Ishizaki
authors.forename: Kaori
authors.initials: K
authors.lastname: Matsushita
authors.forename: Huyen Thi Thanh
authors.initials: HT
authors.lastname: Hoang
authors.forename: Dorothy M
authors.initials: DM
authors.lastname: Agdamag
authors.forename: Cuong Hung
authors.initials: CH
authors.lastname: Nguyen
authors.forename: Vuong Thi
authors.initials: VT
authors.lastname: Tran
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sasagawa
authors.forename: Kunikazu
authors.initials: K
authors.lastname: Saikawa
authors.forename: Raphael
authors.initials: R
authors.lastname: Lihana
authors.forename: Hung Viet
authors.initials: HV
authors.lastname: Pham
authors.forename: Xiuqiong
authors.initials: X
authors.lastname: Bi
authors.forename: Van Thanh
authors.initials: VT
authors.lastname: Ta
authors.forename: Thuc
authors.initials: T
authors.lastname: Van Pham
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ichimura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People; D044383:Black People; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D009856:Oncogene Proteins, Viral / Q000145:classification / Q000235:genetics*; D027383:Papillomaviridae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D050725:Papillomavirus E7 Proteins / Q000145:classification / Q000235:genetics*; D030361:Papillomavirus Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000208:ethnology / Q000821:virology; D010679:Philippines / Q000453:epidemiology; D010802:Phylogeny; D011247:Pregnancy; D015995:Prevalence; D012097:Repressor Proteins / Q000145:classification / Q000235:genetics*; D014744:Vietnam / Q000453:epidemiology; D044465:White People
chemical_list: C068651:E6 protein, Human papillomavirus type 16; C574669:E6 protein, human papillomavirus type 52; C574670:E7 protein, human papillomavirus type 52; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16