Characterization of sequence variations within HPV16 isolates among Indian women: prediction of causal role of rare non-synonymous variations within intact isolates in cervical cancer pathogenesis

Virology. 2008 Jul 20;377(1):143-50. doi: 10.1016/j.virol.2008.04.007. Epub 2008 May 20.

Abstract

We re-sequenced HPV16 genome (~6 kb) implicated in cervical carcinogenesis (LCR, E2, E5, E6, E7, L1, L2) to prioritize sequence variants for functional validation as biomarkers, using CaCx cases (n=74) and asymptomatic controls (n=24). Of the nucleotide variations recorded (n=271), non-synonymous changes in L2 region were significantly higher (p=0.005) among cases (2.67%) compared to controls (1.27%). Using SIFT database, 29 non-synonymous changes (frequency=0.01-0.03) predicted as deleterious to protein functions were identified. Haplotype analysis considering 110 polymorphic variations (frequency> or =0.05) within intact viral isolates (53 CaCx cases and 21 controls) using NETWORK software, confirmed Asian-American (AA, 14.86%) and European (E, 85.14%) variants, differing at 78 positions. The E-variants portrayed thirty-six haplotypes, of which, E-12 was most prevalent within cases (38.1%; 16/42) and controls (28.57%; 6/21) harboring polymorphic variations at 10 positions, in contrast to HPV16R. Cases of the E-12 haplotype harbored 7 deleterious mutations distributed within L1 (n=1), E2 (n=1), E5 (n=1), and L2 (n=4), while none within similar controls. Thus rare deleterious variations within genes implicated in productive infection over the E-12 haplotype background of intact HPV16 isolates might be of causal relevance for CaCx development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Amino Acid Substitution
  • Base Sequence
  • Case-Control Studies
  • DNA Primers / genetics
  • DNA, Viral / genetics
  • Female
  • Genetic Variation*
  • Genome, Viral
  • Human papillomavirus 16 / genetics*
  • Human papillomavirus 16 / isolation & purification*
  • Humans
  • India
  • Middle Aged
  • Papillomavirus Infections / etiology*
  • Papillomavirus Infections / virology*
  • Polymorphism, Single Nucleotide
  • Uterine Cervical Neoplasms / etiology*
  • Uterine Cervical Neoplasms / virology*
  • Virulence / genetics

Substances

  • DNA Primers
  • DNA, Viral