ESTABLISHMENT AND CHARACTERISTICS OF 2 NEW HUMAN MAMMARY-CARCINOMA LINES IN NUDE-MICE WITH SPECIAL REFERENCE TO THE ESTRADIOL-RECEPTOR STATUS AND THE IMPORTANCE OF STROMA FOR IN-VIVO AND IN-VITRO GROWTH

Two new human mammary carcinoma lines originating from surgical materi al were established in nude mice. According to the adopted criteria, t he tumor 4049 has been classified as estradiol receptor positive and m ammary carcinoma 4296 as estradiol receptor negative. Both tumors prov ed to be c-erbB-2 protein positive and EGF-receptor negative. In contr ast to carcinoma 4296, the in vitro growth and the take rate of mammar y carcinoma 4049 in nude mice seems to be dependent on stromal compone nts. Pretreatment of mice with estradiol/peanut oil before tumor engra ftment was an essential precondition for the growth of the primary tum or in nude mice. After successful establishment the tumor growth was s ignificantly stimulated by estradiol. The growth rate of mammary carci noma 4296 was independent of any supplementation of estradiol. The two breast tumors were characterized with regard to their growth behaviou r, histology, and sensitivity to cytostatics and antihormones. They ar e considered suitable tumor models for the testing of antineoplastic s ubstances and for biological experiments.