H. Ozcelik et al., LOW-LEVELS OF EXPRESSION OF AN INHIBITOR OF CYCLIN-DEPENDENT KINASES (CIP1 WAF1) IN PRIMARY BREAST CARCINOMAS WITH P53 MUTATIONS/, Clinical cancer research, 1(8), 1995, pp. 907-912
Recently, several groups have isolated a cell cycle inhibitor gene (CI
P1/WAF1) that is highly induced by wild-type, but not mutant forms of
the p53 tumor suppressor, To test the hypothesis that p53 regulates CI
P1/WAF1 expression in vivo, we evaluated CIP1/WAF2 mRNA expression lev
els in breast carcinomas from individuals with axillary node-negative
disease with and without p53 mutations using quantitative reverse tran
scription-PCR, The data demonstrate that there is a strong negative co
rrelation between the presence of p53 mutations and CIP1/WAF1 expressi
on, suggesting that p53 mutations may reduce its ability to induce CIP
1/WAF1 in vivo, In this study we observed tumors with low levels of CI
P1/WAF1 mRNA in which there were no detectable p53 mutations, Determin
ation of the CIP1/WAF1 levels in such specimens may provide a compleme
ntary strategy for analyzing the effects of p53 defects and/or may sug
gest the presence of alterations (such as coding mutations outside the
conserved regions, promoter mutations, etc.) that may be missed by st
andard techniques.