MULTIDRUG-RESISTANT COLONIC-CANCER CELL-LINE LOVODX IS EFFICIENTLY KILLED BY LYMPHOKINE-ACTIVATED KILLER-CELLS FROM PATIENTS WITH CARCINOMAOF THE COLON

Multidrug-resistant (MDR+) cancer cells have the ability to grow in th e presence of cytotoxic concentrations of antineoplastic drugs as a re sult of possessing the transmembrane drug efflux pump p-glycoprotein. The MDR+ colonic cancer cell line LoVoDx (derived from the drug-sensit ive line LoVo) was tested for sensitivity to lymphokine-activated kill er (LAK) cell-mediated toxicity. LAK cells were cultured from patients with colonic cancer and from matched controls with benign disorders. LAK cells from patients with cancer were as effective as those from co ntrols in mediating cytotoxicity. The MDR+ cell line was significantly more sensitive to LAK cell-mediated cell killing than its parental dr ug-sensitive line LoVo (P < 0.05). These results indicate a possible r ole for adoptive immunotherapy in MDR+ tumours expressing p-glycoprote in.