Reverse transcriptase-PCR analysis of apoptosis-regulating gene expression in human benign prostatic hyperplasia

Background: To determine whether an imbalanced\r\ninteraction between proapototic and antiapoptotic signals may\r\naccount for the loss of the normal cell growth control in benign\r\nprostatic hyperplasia (BPH), the expression of some apoptosisregulating\r\ngenes (bcl-2, bax, c-myc, fas) was investigated. Patients\r\nand Methods: BPH specimens were obtained from 20 patients who\r\nunderwent trans-urethral resection of the prostate (TURP) or\r\nadenomectomy. Gene expression was studied by reverse\r\ntranscriptase-polymerase chain reaction (RT-PCR) and its\r\ncorrelation with age and serum PSA level was also investigated.\r\nResults: Genes were found to be differentially expressed in BPH\r\ntissues. In particular, the antiapoptotic gene bcl-2, which was\r\nfound in 18/20 samples, gave the weakest signal (p<0.05-p<0.001,\r\nWilcoxon’s signed rank test), whereas the cell cycle regulator c-myc\r\nwas detected in all the specimens and was the most highly\r\nexpressed (p<0.001). A positive relationship between the\r\nexpression of bcl-2 and that of the two proapoptotic genes bax and\r\nfas was observed (p<0.05, Spearman's rank correlation test), as\r\nwell as between c-myc and fas levels (p<0.005). Moreover, bax\r\nexpression positively correlated with age and PSA (p<0.02), which\r\nhave also been shown to directly correlate (p<0.01). Conclusion:\r\nThe higher expression of the oncogene c-myc suggests the\r\nactivation of mitogenic signals within hyperplastic prostate tissue\r\nwhich a relatively high expression of the proapoptotic genes bax\r\nand fas fails to counterbalance.