QUANTITATIVE-ANALYSIS OF MUTANT P53 PROTEIN IN BREAST-TUMOR CYTOSOLS AND STUDY OF ITS ASSOCIATION WITH OTHER BIOCHEMICAL PROGNOSTIC INDICATORS IN BREAST-CANCER

Breast tumors are thought to originate, grow, and metastasize in an en vironment which includes steroid hormone receptors, their cognate ster oid ligands, and many gene products which are regulated by steroid hor mone receptor-ligand complexes. In this paper we describe highly sensi tive and quantitative immunofluorometric procedures for measuring thre e proteins that are candidate prognostic indicators in breast cancer, namely, the p53 tumor suppressor gene product, carcinoembryonic antige n (CEA), and prostate specific antigen (PSA). These proteins were quan tified in over 950 cytosolic tumor extracts along with estrogen and pr ogesterone receptors (ER, PR). Association analysis between all five b iochemical parameters revealed strong negative associations between p5 3 and receptors and strong positive associations between CEA and recep tors. Negative associations between p53 and CEA and between CEA and PS A were also found. These associations, not quantitatively studied in p revious reports, are related to each other using a hypothetical model. The observed associations may further contribute to the understanding of the biology of breast tumors.