In vitro uptake and cytotoxicity of adriamycin in primary and metastatic lewis lung carcinoma

The in vitro capacity to take up adriamycin (AM) of murine Lewis lung carcinoma (3LL) cells, derived either from intramuscularly (i.m.) implanted tumor or from its lung metastases, was investigated together with the response of these 2 cell populations to AM treatment. Cell suspensions obtained by mechanical disgregation from primary and secondary tumors directly excised from tumor bearing mice, and primary cultures of these 2 cell populations were exposed to AM in 2 treatment conditions: a higher dose for a short time and a low dose for a longer time. No differences were observed in drug uptake, measured as binding to the cells between primary and metastatic tumor in both experimental conditions. However in the same treatment conditions on the same cell lines AM caused consistently greater cytotoxic effect on pulmonary 3LL metastases than on i.m. primary tumor cells. These findings suggest that the different responses observed may be due to differences on the intrinsic sensitivity of primary and secondary tumor cell populations to AM.