Human papillomavirus does not have a causal role in colorectal carcinogenesis.

Abstract

AIM:

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.

CONCLUSION:

Based on our results, HPV is unlikely involved in colorectal carcinogenesis.

• Authors: Laura Lorenzon, Francesca Mazzetta, Emanuela Pilozzi, Giordana Uggeri, Maria Rosaria Torrisi, Mario Ferri, Vincenzo Ziparo, Deborah French
• Journal: World journal of gastroenterology (World J Gastroenterol) Vol. 21 Issue 1 Pg. 342-50 (Jan 07 2015) ISSN: 2219-2840 [Electronic] United States
• PMID: 25574110 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Viral
• Oncogene Proteins, Viral
• RNA, Messenger
• RNA, Viral

Topics

• Aged
• Aged, 80 and over
• Cell Transformation, Viral
• Chi-Square Distribution
• Colorectal Neoplasms (diagnosis, virology)
• DNA, Viral (genetics)
• Female
• Gene Expression Regulation, Viral
• Human Papillomavirus DNA Tests
• Human papillomavirus 16 (genetics)
• Humans
• Male
• Middle Aged
• Oncogene Proteins, Viral (genetics)
• Papillomavirus Infections (complications, diagnosis, virology)
• Predictive Value of Tests
• Prospective Studies
• RNA, Messenger (genetics)
• RNA, Viral (genetics)
• Risk Factors
• Transcription, Genetic