5516

PPP2CB

PP2Abeta|PP2CB;protein phosphatase 2, catalytic subunit, beta isozyme;PPP2CB;protein phosphatase 2, catalytic subunit, beta isozyme

PP2A-beta|protein phosphatase 2 (formerly 2A), catalytic subunit, beta isoform|protein phosphatase 2, catalytic subunit, beta isoform|protein phosphatase 2A catalytic subunit, beta isoform|protein phosphatase type 2A catalytic subunit|serine/threonine pro

8p12

protein-coding

BACKGROUND: Allelic losses on chromosome 8p are common in prostate carcinoma, but it is not known exactly how they contribute to cancer development and progression. MATERIALS AND METHODS: expression of 12 genes located across chromosome 8p, including established tumor suppressor candidates (CSMD1, DLC1, NKX3.1), and others from a new microarray-based comparison was studied by quantitative RT-PCR in 45 M0 prostate carcinomas and 13 benign prostate tissues. RESULTS: Significantly reduced expression was observed for two protein phosphatase subunit genes (PPP2CB, PPP3CC) and two TRAIL decoy receptors (TNFRSF10C/DcR1, TNFRSF10D/DcR2), but not for the three established candidates nor for TRAIL death receptor genes. Low expression of PPP3CC and TNFRSF10C located at 8p21.3 was highly significantly associated with tumor recurrence. In addition to allele loss, down-regulation of TNFRSF10C and TNFRSF10D was found to be associated with hypermethylation, although bisulfite sequencing usually revealed it to be partial. CONCLUSION: Our data strongly support a recent proposal that a segment at 8p21.3 contains crucial prostate cancer tumor suppressors. In addition, they raise the paradoxical issue of why TRAIL decoy receptors rather than death receptors are down-regulated in aggressive prostate cancer.