PRLTS GENE ALTERATIONS IN HUMAN PROSTATE-CANCER

Since loss of heterozygosity on 8p22-p21.3 has been found frequently i n prostate cancer, the status of a candidate tumor suppressor gene nam ed PRLTS gene, recently cloned from the same region in some human mali gnancies, was examined in the present study. DNAs were isolated from 6 9 Japanese prostate cancer patients (37 localized and 32 cancer-death cases). Loss of heterozygosity at this gene locus was observed in 15 o f 36 (42%) localized prostate cancer patients and 22 of 32 (69%) cance r-death patients. One cancer-death patient had a missense mutation, AC G-->ATG (Thr-->Met) at codon 64 in metastatic tumor tissues of pelvic lymph node and liver, and these tissues showed loss of the homologous allele, indicating that ''two-hit'' mutation of the PRLTS gene had occ urred in this case. The others did not show any mutation, regardless o f the presence or absence of loss of heterozygosity. Although loss of heterozygosity at the PRLTS gene locus is a relatively common abnormal ity, mutation of this gene is rare in prostate cancer.