Comparative sensitivity of two mouse lymphoid tumour cell lines (P388 and P388D1) to five anticancer drugs in vitro

By Arnould, R. - Dubois, J. - Abikhalil, F. - Libert, A. - Ghanem, G. - Atassi, G. - Hanocq, M. - Lejeune, F.J.

The sensitivity and the selectivity of two murine lymphoid cell lines (P388 and P388D1) to five chemotherapeutic drugs were investigated in vitro. The cytotoxicities of melphalan, daunorubicin, hexamethylmelamine (HMM), hydroxymethylpentamethylmelamine and dihydroxymethyltetramethylmelamine, two HMM derivatives, were measured in the two cell lines using two different techniques: reduction of a tetrazolium derivative (MTT) and tritiated thymidine uptake into DNA. Cytotoxicity was expressed by the 50% inhibitory concentration (IC50) after one hour and after exposure of cells to each drug for two days. The IC50 results indicate that the P388 cells were generally more sensitive to melphalan, daunorubicin, hydroxymethylpentamethylmelamine and dihydroxymethyltetramethylmelamine than the P388D1 cell line. HMM was found to be inactive in both cell lines. Despite the lower sensitivity of the P388D1 cell line compared with the P388 cell line, because of its greater homogeneity, it could replace the P388 line for the in vitro assays, bearing in mind that the P388D1 cell line sensitivity is 1.21-24.63 times lower than that of the P388 cell line, at least as far as the drugs tested are concerned. Moreover, our results emphasise that variations of sensitivity could occur with repeated passage in vitro.