Inducible antisense inhibition of erbB-2 expression reduces anchorage independent growth of ovarian carcinoma cells

We have investigated the effect of c-erbB-2 expression on the growth of ovarian carcinoma cell lines using antisense methodology. A 1.5 kb fragment of c-erbB-2 cDNA was cloned in an antisense and sense orientation into an IPTG inducible vector. These vectors were stably transfected into two ovarian carcinoma cell lines, one of which (NIH:OVCAR-8) grew well in soft agar. Inhibition of expression of endogenous c-erbB-2 protein was detected by immunoprecipitation and Western blot in both of the induced transfectants with the antisense construct. Although growth in monolayer culture was unaffected, NIH:OVCAR-8 cells transfected with the antisense construct and induced with IPTG lost their ability to form colonies in soft agar. Consequently, endogenous expression of c-erbB-2 modulates anchorage-independent growth of NIH:OVCAR-8.