NOVEL CELLULAR MARKERS IN BREAST-CANCER - DIFFERENTIAL PRESENCE OF P23K AND P30.33K PROSOMAL ANTIGENS IN TUMORS OF PARSI AND NON-PARSI WOMEN

Epidemiological studies have revealed that Parsi women have a higher i ncidence of breast cancer than non-Parsis and that they are more susce ptible to breast cancer. We have studied the cellular distribution of two prosomal proteins p23K in parallel to the p30.33K and proliferatio n marker Ki-67 as potential markers to identify high risk population f or breast cancers. Flow cytometry data demonstrated that the Parsi ben ign and non-Parsi malignants have a higher number of cells labelled wi th these two prosomal protein antibodies than the non-Parsi benign and European 'normals'. Using immunohistochemical methods, p23 K was foun d to be significantly higher in Parsi and non-Parsi malignants as well as in non-Parsi benigns. In our FCM analysis, intergroup comparison s howed, interestingly, a significantly higher expression of both p23K a nd p30.33K in Parsi benigns as compared to non-Parsis, raising the pos sibility that benign tumors of Parsis represent already premalignant l esions. The present study, in addition, proposes the prosomal antigens as likely cell proliferation markers comparable to Ki-67.