DIFFERENTIAL CHARACTERISTICS OF 2 NEW TUMORIGENIC CELL-LINES OF HUMANBREAST-CARCINOMA ORIGIN

Permanent human tumor cell lines are an important tool for the study o f breast cancer. Two new breast cancer cell lines (BrCa-MZ-01 and BrCa -MZ-02) were isolated from a solid tumor and a pleural effusion, respe ctively. One cell line was established from a medullary carcinoma, the other from a ductal carcinoma. These cells exhibit ultrastructural an d immunohistochemical features of epithelial cells of mammary origin. Intermediate filament and cytokeratin typing showed a clear predominan ce of the simple-epithelial cytokeratins CK 8, CK 18 and CK 19, althou gh the expression was reduced in comparison to the hormone receptor-po sitive reference cell lines MCF-7 and ZR-75-I. Both cell lines produce d slow-growing tumors after subcutaneous (s.c.) transplantation of I x 10(7) viable tumor cells into nude mice. The cell line BrCa-MZ-01 exp resses the estrogen and progesterone receptor, whereas the cell line B rCa-MZ-02 remains negative. Both cell lines are positive for secretion of platelet-derived growth factor (PDGF) and transforming growth fact or-beta (TGF-beta), whereas interleukin-6 (IL-6) is only secreted by t he cell line BrCa-MZ-02. (C) 1998 Wiley-Liss, Inc.