Washington, Jan 14 (IANS): Scientists have for the first time identified a critical cancer-causing component in the virus that is behind the most common cancer among HIV-infected people.

The discovery paves the way for developing therapies that prevent the cancer called Kaposi’s sarcoma, and other related cancers in HIV-infected people.

“The mechanism behind the Kaposi’s sarcoma-associated herpesvirus (KSHV), that causes healthy cells to become malignant, was not well understood despite decades of studies,” said S.J. Gao, professor of molecular microbiology and immunology at the Keck School of Medicine of the University of Southern California (USC).

“This is the first time that a viral factor has been shown to be required for KSHV-induced malignant transformation. We have identified a mechanism by which these tiny viral molecules cause the cells to become malignant,” Gao added.

Distinguished by dark lesions on the skin, Kaposi’s sarcoma most commonly develops in people who are infected with KSHV and also have compromised immune systems, according to a report by American Cancer Society published in the journal PLOS Pathogens.

Gao and colleagues from the University of Texas at San Antonio (UTSA) and University of Texas Health Science Centre at San Antonio studied KSHV using a rat stem cell model.

Till date, researchers had been unable to study the virus because most healthy cells, once infected with KSHV, died before turning into cancer cells.

The team identified a cluster of viral microRNA molecules that are necessary to transform healthy cells into cancerous ones.

When this microRNA cluster was suppressed, the cells died after they were infected with KSHV.

“Our results suggest that this cluster of KSHV microRNAs and their regulated pathway may be potential targets for new therapies for KSHV-related cancers,” said Gao.