HHV-8 (KSHV) does not establish latency in prostate cancer cell lines

BACKGROUND. HHV-8 is a new herpesvirus found in lesions of Kaposi's sarcoma and some lymphoproliferative diseases. More recently, a report stated that normal prostate tissue also contains the virus. METHODS. The expression of HHV-8 was examined by a sensitive reverse-transcriptase PCR for the viral genes ORF 72, ORF 73, ORF 74, and ORF 75. In coculture experiments we attempted to infect 3 commonly studied prostate cancer cell lines using induced and uninduced lymphoid cell lines harboring HHV-8 (KS-1, BC-1, and Bc-2). For induction of viral genes, butyrate and phorbol esters were used. RESULTS AND CONCLUSIONS. At baseline, prostate cancer cell lines LNCaP, DU- 145, and PC-3 did not express viral gene products. Extensive coculture experiments were also negative. In no instance could latency for the virus be established. Our results argue against the involvement of HHV-8 in prostate cancer and for a limited tissue tropism of HHV-8.