title: Role of Human papilloma virus infection and altered methylation of specific genes in esophageal cancer.
abstract: BACKGROUND
  Evaluation of Human papilloma virus (HPV) and its association with promoter methylation of candidate genes, p53 and Aurora A in esophageal cancer.
  
  
  METHODS
  One hundred forty-one esophageal tissue samples from different pathologies were evaluated for HPV infection by PCR, while the promoter methylation status of p53 and Aurora A was assessed by methylation-specific restriction based PCR assay. Statistical analyses were performed with MedCalc and MDR software.
  
  
  RESULTS
  Based on endoscopy and histopathology, samples were categorized: cancers (n=56), precancers (n=7), esophagitis (n=19) and normals (n=59). HPV infection was found to be less common in cancers (19.6%), whereas its prevalence was relatively high in precancers (71.4%), esophagitis (57.8%) and normals (45.7%). p53 promoter methylation did not show any significant difference between cancer and normal tissues, whereas Aurora A promoter methylation demonstrated significant association with disease (p=0.00016, OR:5.6452, 95%CI:2.18 to 14.6) when compared to normals. Aurora A methylation and HPV infection was found in a higher percentages of precancer (66.6%), esophagitis (54.5%) and normal (45.2%) when compared to cancers (14.2%).
  
  
  CONCLUSIONS
  Aurora A promoter methylation is significantly associated with esophageal cancer, but the effect of HPV infection on this epigenetic alteration is not significant. However MDR analysis showed that the hypostatic effect of HPV was nullified when the cases had Aurora methylation and tobacco exposure. Further HPV sub-typing may give an insight into its reduced prevalence in esophageal cancer verses normal tissue. However, with the present data it is difficult to assign any significant role to HPV in the etiopathology of esophageal cancer.
authors.affiliation: Department of Genetics, Vasavi Medical and Research Centre, Kamineni Hospitals, LB Nagar, Andhra Pradesh, India. greenpastures@gmail.com
authors.forename: Mohammed Khaliq
authors.initials: MK
authors.lastname: Mohiuddin
authors.forename: Srinivas
authors.initials: S
authors.lastname: Chava
authors.forename: Pavani
authors.initials: P
authors.lastname: Upendrum
authors.forename: Madhavi
authors.initials: M
authors.lastname: Latha
authors.forename: Syeda
authors.initials: S
authors.lastname: Zubeda
authors.forename: Ajith
authors.initials: A
authors.lastname: Kumar
authors.forename: Yog Raj
authors.initials: YR
authors.lastname: Ahuja
authors.forename: Qurratulain
authors.initials: Q
authors.lastname: Hasan
authors.forename: Vasavi
authors.initials: V
authors.lastname: Mohan
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology / Q000821:virology; D000328:Adult; D064096:Aurora Kinase A / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000473:pathology / Q000821:virology; D016022:Case-Control Studies; D004279:DNA, Viral / Q000235:genetics; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000473:pathology / Q000821:virology; D004941:Esophagitis / Q000235:genetics / Q000473:pathology / Q000821:virology; D004947:Esophagus / Q000378:metabolism / Q000473:pathology / Q000821:virology; D005260:Female; D005500:Follow-Up Studies; D005764:Gastroesophageal Reflux / Q000235:genetics / Q000473:pathology / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D027383:Papillomaviridae; D030361:Papillomavirus Infections / Q000235:genetics* / Q000473:pathology / Q000821:virology; D016133:Polymerase Chain Reaction; D011230:Precancerous Conditions / Q000235:genetics / Q000473:pathology / Q000821:virology; D011379:Prognosis; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: D004279:DNA, Viral; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; C576917:AURKA protein, human; D064096:Aurora Kinase A