IMMUNOENZYMATIC ASSAY OF MR 52,000 CATHEPSIN-D IN 182 BREAST-CANCER CYTOSOLS - LOW CORRELATION WITH OTHER PROGNOSTIC PARAMETERS

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  • 15 January 1988
    • journal article
    • research article
    • Vol. 48  (2) , 462-466
Abstract
The Mr 52,000 cathepsin-D-like protease induced by estrogens in MCF7 human breast cells was assayed in 182 primary breast cancer cytosols prepared for receptor assays from pre- and post-menopausal patients. Using two solid-phase sandwich immunoenzymatic assays, we quantified the total Mr 53,000 cathepsin D (52K-cath-D) (the Mr 52,000 precursor protein and its Mr 48,000 and 34,000 processed forms) and the Mr 52,000 precursor alone. The value of total 52K-cath-D varied between 3 and 165 pmol/mg protein and the proportion of the precursor varied from 0 to 28% of total 52K-cath-D. There was no correlation between the concentrations of 52K-cath-D and estrogen receptor, but the estrogen receptor status ( > or < 10 fmol/mg protein) was correlated to the 52K-cath-D status ( > or < 15 pmol/mg protein) according to the .chi.2 test (P < 0.001). The correlation with progesterone receptor concentrations and status was low (r = 0.43) and absent, respectively. There was no correlation with Scarff and Bloom stages, tumor size, or patient''s age. The percentage of patients with invaded lymph nodes was significantly higher (80%) in the subgroup with the highest total 52K-cath-D levels ( .gtoreq. 42 pmol/mg protein), representing only 12% of the population but not in the total population. On the basis of this prospective study, before clinical follow-up can be evaluated, we conclude that in the total population examined, the 52K-cath-D concentration was only correlated with estrogen receptor status, but not with any other prognostic parameter.