Signaling Activity and Prognostic Significance of Variant Forms of P185HER-2/neu in Breast Cancer.

摘要

We investigated an N-terminally truncated HER-2/neu product of 95 kDa, for its relationship to shedding of the extracellular domain (ECD) of P185HER-2 and for its association with prognostic factors in human breast cancer. P95 had in vitro kinase activity indicating it is active as a signaling protein and its levels correlated with the ECD shed from different cells under varied conditions. Cancer tissues were analyzed by western blotting and scored for p95 and for p185HER-2/neu expression. Of 161 breast cancer tissues, 22.4% expressed p95, 21.7% overexpressed p185, and 14.3% were both p95 positive and overexpressed p185. A higher proportion of node positive patients (23 of 78) than node negative patients (9 of 63) expressed p95 in all tumors combined (P= . 032).