Isolation and characterization of doxorubicin-resistant Lewis lung carcinoma variants

A series of drug-resistant variants of the murine Lewis lung carcinoma (3LL-CK) cell line has been isolated using stepwise selection in increasing concentrations of doxorubicin. These variants exhibited classical multidrug resistance as evidenced by decreased doxorubicin accumulation, cross-resistance to vinblastine, reversibility of resistance by verapamil, and overexpression of P-glycoprotein. When the doxorubicin-resistant 3LL-CK cell populations were injected into the tail veins of B6D2F1 mice, their metastatic abilities were consistently reduced compared with that of the parental line.