The potential association between xenotropic murine leukaemia virus-related gammaretrovirus （XMRV） and prostate cancer （PCa） has been documented since 2006, It is important for furthering our understanding of the biological mechanisms of PCa to ascertain whether this association is causal. To summarize the available information on the epidemiological and laboratory findings of the association, we conducted a literature search of the PubMed electronic database （from March 2006 to February 2011） to identify relevant published studies that examined the association between XMRV and PCa, Although several studies showed the positive association between XMRV and PCa, more recent studies did not support this conclusion, The positive findings might be due to contamination of human samples, Further studies are needed to clarify this association,
Persistent activation of Survivin and its overexpression contribute to the formation, progression and metastasis of several different tumor types. Therefore, Survivin is an ideal target for RNA interference mediated-growth inhibition. Blockade of Survivin using specific short hairpin RNAs （shRNA） can significantly reduce prostate tumor growth. RNA interference does not fully ablate target gene expression, owing to the idiosyncrasies associated with shRNAs and their targets. To enhance the therapeutic efficacy of Survivin-specific shRNA, we employed a combinatorial expression of Survivin-specific shRNA and gene associated with retinoid-interferon-induced mortality-19 （GRIM-19）. Then, the GRIM-19 coding sequences and Survivin-specific shRNAs were used to create a dual expression plasmid vector and were carried by an attenuated strain of Salmonella enteric serovar typhimurium （S. typhimurium） to treat prostate cancer in vitro and in vivo. We found that the co-expressed Survivin-specific shRNA and GRIM-19 synergistically and more effectively inhibited prostate tumor proliferation and survival, when compared with treatment with either single agent alone in vitroand in vivo. This study has provided a novel cancer gene therapeutic approach for prostate cancer.
