STUDIES ON THE HUMAN MAMMARY-CARCINOMA CELL-LINE MCF7 AND ITS SUBLINERESISTANT TO DOXORUBICIN - A PRELIMINARY-REPORT ON CYTOGENETIC AND IMMUNOCYTOCHEMICAL CHARACTERIZATION

We report herein some cytogenetic and immunocytochemical studies on th e human mammary carcinoma cell line MCF7/WT and its subline resistant to Doxorubicin (Dx), MCF7/DxR. The MCF7 line sensitive Dx shows a near triploid chromosome number (modal class 67), whereas most resistant c ells (95% of the total) have a reduced chromosome number (modal class 51). Chromosomal aberrations are extremely high in both groups but are only slightly higher in the resistant line, although qualitative diff erences are seen, the sensitive line being characterized by the presen ce of rings and absence of minutes. Cytoskeletal analysis reveals the presence of cytokeratins in the sensitive and resistant cell line. Sli ght differences are seen in the patterns of immunoreactivity with the polyclonal antikeratin antibody between the two cell lines.