title: Human papillomavirus does not have a causal role in colorectal carcinogenesis.
abstract: OBJECTIVE
  To investigate the presence of human papillomavirus (HPV) DNA along with the integration, the quantification and the expression of the HPV16 in colorectal cancers.
  
  
  METHODS
  A prospective series of colorectal tumors were genotyped for HPV DNA. The clinical and pathological variables of the HPV-positive tumors were compared to those of HPV-negative samples. The integration status of HPV16 was evaluated by calculating E2/E6 ng ratios. HPV16-positive tumors were also evaluated for (1) E2, E4, E5, E6 and E7 viral gene ng quantification; (2) relative quantification compared to W12 cells; and (3) viral E2, E4, E5, E6 and E7 mRNA transcripts by real-time polymerase chain reaction.
  
  
  RESULTS
  HPV infection was detected in 16.9% of all tumors examined, and HPV16 was the most frequent type detected (63.6% of positive tissues). Notably, the clinical and pathological features of HPV-positive colorectal cancers were not significantly different than those of HPV-negative cancers (χ (2) and t-test for all clinical and pathological features of HPV-positive vs HPV-negative colorectal cancers: p ns). HPV16 DNA was present exclusively in episomal form, and the HPV16 E2, E4, E5, E6 and E7 genes were detected in trace nanogram quantities. Furthermore, the HPV16 genes ranged from 10(-3) to 10(-9) compared to W12 cells at an episomal stage. Although the extractions were validated by housekeeping gene expression, all the HPV16 positive tissues were transcriptionally inactive for the E2, E4, E5, E6 and E7 mRNAs.
  
  
  CONCLUSIONS
  Based on our results, HPV is unlikely involved in colorectal carcinogenesis.
authors.affiliation: Laura Lorenzon, Mario Ferri, Vincenzo Ziparo, Surgical and Medical Department of Translational Medicine, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Sant'Andrea Hospital of Rome, 00189 Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Lorenzon
authors.affiliation: Laura Lorenzon, Mario Ferri, Vincenzo Ziparo, Surgical and Medical Department of Translational Medicine, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Sant'Andrea Hospital of Rome, 00189 Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Mazzetta
authors.affiliation: Laura Lorenzon, Mario Ferri, Vincenzo Ziparo, Surgical and Medical Department of Translational Medicine, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Sant'Andrea Hospital of Rome, 00189 Rome, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Pilozzi
authors.affiliation: Laura Lorenzon, Mario Ferri, Vincenzo Ziparo, Surgical and Medical Department of Translational Medicine, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Sant'Andrea Hospital of Rome, 00189 Rome, Italy.
authors.forename: Giordana
authors.initials: G
authors.lastname: Uggeri
authors.affiliation: Laura Lorenzon, Mario Ferri, Vincenzo Ziparo, Surgical and Medical Department of Translational Medicine, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Sant'Andrea Hospital of Rome, 00189 Rome, Italy.
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Torrisi
authors.affiliation: Laura Lorenzon, Mario Ferri, Vincenzo Ziparo, Surgical and Medical Department of Translational Medicine, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Sant'Andrea Hospital of Rome, 00189 Rome, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Ferri
authors.affiliation: Laura Lorenzon, Mario Ferri, Vincenzo Ziparo, Surgical and Medical Department of Translational Medicine, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Sant'Andrea Hospital of Rome, 00189 Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Ziparo
authors.affiliation: Laura Lorenzon, Mario Ferri, Vincenzo Ziparo, Surgical and Medical Department of Translational Medicine, Faculty of Medicine and Psychology, University of Rome "La Sapienza", Sant'Andrea Hospital of Rome, 00189 Rome, Italy.
authors.forename: Deborah
authors.initials: D
authors.lastname: French
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002472:Cell Transformation, Viral; D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000821:virology*; D004279:DNA, Viral / Q000235:genetics; D005260:Female; D015967:Gene Expression Regulation, Viral; D061809:Human Papillomavirus DNA Tests; D052162:Human papillomavirus 16 / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009856:Oncogene Proteins, Viral / Q000235:genetics*; D030361:Papillomavirus Infections / Q000150:complications / Q000175:diagnosis / Q000821:virology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D012307:Risk Factors; D014158:Transcription, Genetic
chemical_list: D004279:DNA, Viral; D009856:Oncogene Proteins, Viral; D012333:RNA, Messenger; D012367:RNA, Viral
keywords: Carcinogenesis; Colorectal cancer; Human papillomavirus; W12