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HHV-6, EBV and CMV found in GI tract cancers

In All, Liver Disease, Uncategorized by Kristin Loomis

A group from Washington University used a bioinformatics system called VirusScan to analyze RNA-Seq data sets from 6,813 human tumors and compare them to those of adjacent normal tissue. Tumor samples representing 23 different forms of cancer were analyzed. HHV-6, EBV, and CMV were found at significantly high levels in GI tract cancer tissue.

The group analyzed 6,813 human tumors and 559 adjacent normal samples across 23 cancer types. Although EBV, CMV, and HHV-6 were found at high levels (reads per hundred million processed) in gastrointestinal-related cancers, they were not detected in paired adjacent normal samples.

Overall, 505 viruses were identified, but three human herpesviruses were found at a high prevalence in gastrointestinal-related cancers, including rectal adenocarcinomas and esophageal, stomach, and colon cancers. HHV-6 was detected in 26 cases of colon cancer, 9 cases of stomach cancer, 7 cases of esophageal cancer, and 6 cases of rectal adenocarcinomas. Despite being found in gastrointestinal-related cancers, HHV-4, HHV-5, and HHV-6 were not detected in paired adjacent normal samples.

HHV-6 was also detected in numerous samples from other types of cancer including head and neck squamous carcinoma (9 cases), lung squamous cell carcinoma (6 cases), lung adenocarcinoma (4 cases), and pancreatic adenocarcinoma (4 cases).

Human papillomavirus was the most common virus found in brain tumors, but HHV-6 was the most common herpesvirus found. HHV-6 was found in glioblastoma (1 case) and low-grade glioma (3 cases). CMV was found in one case.

The authors note that viral infection contributes to at least 10-15% of human cancers, and is suspected in others.

For more information, read the full paper (Cao 2016).