Mutation analysis of the p51 gene and correlation between p53, p73, and p51 expressions in prostatic carcinoma

BACKGROUND. p73 and p51 are genes possessing amino-acid similarities to p53 . We previously found no mutation in p73 in prostatic carcinoma, but did fi nd abnormal expression of the gene. Involvement of these genes in prostatic carcinogenesis is still poorly understood. METHODS. Mutation analysis of the p51 gene and allelotyping of 3q28, on whi ch p51 lies, were performed. Expression of p53, p73, and p51 was examined u sing reverse transcription-polymerase chain reaction, and expression levels were compared. RESULTS. No mutation in p51 was found (0/55 cases). Loss of heterozygosity at 3q28 was detected in 6 of 28 cases (21.8%). By expression analysis we fo und that in p53, 4 of 38 cases (10.5%) showed downregulation. No cases show ed upregulation of p53. in contrast, p73 and p51 were downregulated in 42.1 and 39.5% of cases, respectively, and upregulated in 31.5 and 34.2% of cas es, respectively. Expression levels of p51 corresponded with those of p73 i n 25 of 38 cases (65.8%). CONCLUSIONS. Somatic mutations in p73 and p51 are not important in prostati c carcinogenesis. These genes may be associated with tumors by expression l evels and may have roles in addition to tumor suppression. Prostate 47:85-9 0, 2001. (C) 2001 Wiley-Liss, Inc.