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 primary ductal infiltrating breast carcinoma. The epithelial nature of this cell line was confirmed by ultrastructural analysis and demonstrated the retention of structural properties characteristic of the original 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 chromosome number between 60-61 with eight recurrent marker chromosomes, and it presented a doubling time of 30.5 hr. Scatchard analysis demonstrated that both primary tumor and BRC-230 cells were estrogen and progesterone receptor negative. Immunoenzymatic and radioimmunoassays showed a production of marker antigens (CEA, TPA, CA125, CA15-3, CA19-9) which 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 tissue showed overlapping results to all tested antiblastic drugs. BRC-230 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 original tumor nor in BRC-230 cells; the mdr-1 gene was also present in a single copy. We conclude from these studies that the BRC-230 cell line maintains 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.