ESTABLISHMENT AND CHARACTERIZATION OF A NEW CELL-LINE FROM PRIMARY HUMAN BREAST-CARCINOMA

A new cell, line (BRC-230) was established from surgical material of p rimary ductal infiltrating breast carcinoma. The epithelial nature of this cell line was confirmed by ultrastructural analysis and demonstra ted the retention of structural properties characteristic of the origi nal tumor. The BRC-230 cell line induced tumor in athymic Cr1:nu/nu(CD -1)BR nude mice, it possessed an abnormal karyotype with a modal chrom osome number between 60-61 with eight recurrent marker chromosomes, an d it presented a doubling time of 30.5 hr. Scatchard analysis demonstr ated that both primary tumor and BRC-230 cells were estrogen and proge sterone receptor negative. Immunoenzymatic and radioimmunoassays showe d a production of marker antigens (CEA, TPA, CA125, CA15-3, CA19-9) wh ich was similar in the patient's serum and BRC-230 cells. The in vitro drug sensitivity assay of the cell line and of the parental tumor tis sue showed overlapping results to all tested antiblastic drugs. BRC-23 0 cells were resistant to 4-Idroperoxy-cyclophosphamide, Idarubicinol, Mitoxantrone, Etoposide, 4'Epidoxorubicin, and Doxorubicin, showing a multiple drug resistance phenotype. Amplification or rearrangement of Her-2neu, Ha-ras, and C-myc genes was observed neither in the origina l tumor nor in BRC-230 cells; the mdr-1 gene was also present in a sin gle copy. We conclude from these studies that the BRC-230 cell line ma intains the same characteristics as the original tumor and may provide us with a good model to study in vitro the biology of drug resistance of breast cancer.