The over-expression of P-glycoprotein in K-562 and DAUDI cells, is associated with a high susceptibility to NK and LAK cells

We evaluated the susceptibility to natural killer (NK) or lymphokine activated killer (LAK) cell-mediated cytolysis of two pairs of drug sensitive/resistant tumor cell lines which were extensively characterized at phenotypic and genotypic level. In the DAUDI cell system, the acquired capability of tumor cell variants to grow in the presence of a relatively high concentration of vinblastine (VBL) is associated with a marked increase to NK and LAK susceptibility. In contrast in the K-562 cell system, no correlation between drug resistance, P-glycoprotein expression and susceptibility to NK or LAK activity seems to occur.