Presence of Human Papillomavirus DNA in Colorectal Cancer Tissues in Shiraz, Southwest Iran

Abstract

Background: Colorectal cancer is one of the most common cancers worldwide. Viruses including human papillomavirus (HPV) have been reported to be associated with different cancers but any association with colorectal cancers remains controversial. Aim: To evaluate any association between HPV infection and adenocarcinoma of the colon and adenomatous polyps. Materials and Methods: Paraffin-embedded tissue specimens of 70 colorectal adenocarcinomas, 70 colorectal adenomatous polyps, and 70 colorectal normal tissues were subjected to DNA extraction. The quality of the extracted DNA was confirmed by amplification of a β-globin fragment using polymerase chain reaction (PCR). PCR using specific primers were performed to detect HPV DNA. Specific primers targeting the E6 region of the HPVs 16 and 18 were used for genotyping. Results: HPV DNA was detected in 2 (2.85%) out of 70 adenocarcinoma colorectal tissues and 4 (5.71 %) out of 70 adenomatous colorectal tissues. All normal colorectal tissues were negative for HPV DNA. HPV-16 was the most predominant genotype (5 sample) followed by HPV-18 (4 sample). Despite the above observations, statistical analyses indicated no significant differences in the frequencies of HPV positive subjects between the cancerous and normal samples. Conclusions: Although the differences observed in the frequencies of HPV positive cases in our study was not significant relative to those of control subjects, the fact of 6 positive samples among cancerous tissues, may still suggest a role of HPV in colorectal carcinogenesis. The study collectively indicated that some colorectal cancerous tissues are infected with high risk HPV genotype. The findings merit more investigation.

Does human papillomavirus cause human colorectal cancer? Applying Bradford Hill criteria postulates

“…The positivity ratio of HPV detection in CRC samples was varied population wise from 0% [ 11 , 12 , 17 , 23 , 26 , 32 , 41 , 43 , 45 , 46 , 50 , 59 ] to 100% [ 13 , 54 ] in all the 59 studies, whereas the positivity ratio of HPV detection in normal and adjacent/benign samples was varied from 0% [ 21 , 22 , 29 , 30 , 43 , 49 ] to 84% (28) and 0% [ 17 , 22 , 26 , 41 , 42 , 45 , 46 , 50 , 52 , 57 ] to 69.56% [ 54 ], respectively.…”

No Detection of Streptococcus gallolyticus and Helicobacter pylori in Colorectal Cancer Tissue Samples in Shiraz, Iran

“…Previously, we reported a low frequency of papillomavirus infection in colorectal cancer (18). In our new study, the study population was also evaluated for bacterial infection.…”

The Very Low Frequency of Epstein-Barr JC and BK Viruses DNA in Colorectal Cancer Tissues in Shiraz, Southwest Iran

“…In the growing list of cancer-related risk factors, viral infections have a special place with a lot of unsolved issues (Haggar et al, 2009;Jemal et al, 2011;Mahmoudvand et al, 2015). Viruses, especially DNA viruses such as polyomaviruses (JCV and BKV), herpesviruses (Epstein-Barr virus), human papilloma viruses and hepatitis B virus are the causative agents of 15-20% of human cancers including Burkitt's lymphoma, nasopharyngeal carcinoma, Hodgkin's lymphoma, cervical cancer and hepatocellular carcinoma (Sarvari et al, 2014;Polz-Gruszka et al, 2015;Schafer et al, 2015).…”