P53 ASSOCIATED WITH CATHEPSIN-D IN PRIMARY BREAST-CANCER

The p53 protein was identified in primary breast carcinomas by specifi c binding of PAb1801 and PAb240 antibodies. Using sodium dodecyl sulfa te electrophoresis followed by immunoblotting on nitrocellulose membra ne, the p53 protein was identified in 36 nuclear fractions obtained fr om 60 primary breast cancers; semiquantitation of p53 was performed by densitometric scanning. The total cathepsin D content, the estrogen a nd progesterone receptor concentration values and the axillary lymph n ode involvement were also assessed. Tumors expressing p53 had signific antly higher levels of cathepsin D than those in which p53 was undetec table. p53 expression was strongly associated with low or negative est rogen receptor values; progesterone receptor concentrations were also significantly higher in p53-negative tumors than in those tumors with detectable p53 levels. Finally, a significant relationship between p53 expression and lymph node metastasis was observed. It was concluded t hat a positive association between p53 and cathepsin D values exists w hich is of prognostic interest in that both cathepsin D and p53 are as sociated with a high tumor grade and metastatic activity.