ErbB receptor expression and growth response to heregulin beta 1 in five ovarian carcinoma lines

SKOV-3, NIH:OVCAR-3, NIH:OVCAR-8, Ovca 429 and Ovca 433 ovarian carcinoma cell lines were examined to correlate biological behavior (growth in monolayer and soft agar) with erbB family receptor expression levels and response to recombinant Heregulin beta1 (Hrg). While all lines expressed variable amounts of each receptor, erbB-3 and to a lesser extent erbB-2 were constitutively tyrosine phosphorylated in all lines. Hrg beta1 treatment enhanced only erbB-3 tyrosine phosphorylation; however, the addition of Hrg in low serum did not stimulate ovarian cell growth, unlike all three breast cancer cell lines examined. In addition, all five of the ovarian carcinoma cell lines expressed Hrg mRNA by RT-PCR, unlike two of the three breast cancer cell lines. These results suggest the apparent importance of erbB-3 and endogenous Hrg in ovarian carcinoma cell growth in vitro.