Public release date: 26-Oct-2007

For the first time, a new screening method shows promise for identifying new human tumor viruses, as well as determining which cancers are caused by infection and which are not. The researchers report their findings in the October 2007 issue of the Journal of Virology.

Statistics now show that infection contributes to over 20% of human cancers worldwide. Presently, the list of confirmed carcinogenic infectious agents is short, however studies suggest that new infectious agents yet to be identified contribute to a wide range of diseases, including cancers. A major obstacle in new pathogen discovery is whether an infectious agent isn’t identified due to lack of presence or technical failure, emphasizing the need for reliable screening methods

Conjunctival carcinomas are tumors long suspected of having a direct infectious origin, meaning direct carcinogens are present in the tumor mass with at least one genome copy per cell. In the study researchers developed a process called digital transcript subtraction (DTS), a system for subtracting known human sequences from library data sets while leaving nonhuman sequences behind for further analysis. DTS analysis of 241,122 conjunctival carcinoma cells disclosed only 21 that didn’t concur with previous sequences from human databases, indicating its ability to screen human sequence data and identify those most likely to be of viral origin