Welcome to the Singh Laboratory
Our research interests involve many aspects of retroviral replication. We study HIV-1, Moloney murine leukemia virus, and XMRV, a novel xenotropic murine-like retrovirus that has recently been implicated in human prostate cancer.
Our studies with XMRV consist of elucidating the role of this newly discovered virus in human prostate cancer. XMRV is the first gammaretrovirus known to infect humans. While gammaretroviruses have well-characterized oncogenic effects in animals, they have not been shown to cause human cancers. Our experiments show that XMRV is indeed a gammaretrovirus with protein composition and particle ultrastructure highly similar to Moloney murine leukemia virus, another gammaretrovirus that we have studied for the last several years. We analyzed 334 consecutive prostate resection specimens using a quantitative PCR assay and immunohistochemistry with an anti-XMRV specific antiserum. We found the virus in 27% of prostate cancers. XMRV proteins are expressed primarily in malignant epithelial cells, suggesting that retroviral infection may be directly linked to tumorigenesis. We have shown that XMRV-infection is associated with prostate cancer, especially higher-grade cancers. We are currently investigating possible mechanisms of oncogenesis by XMRV in cultured cells, in human tumors and in a mouse model.