Comparative effects of taxol and Taxotere on two different human carcinoma cell lines

The effects of taxoids (taxol and Taxotere) were followed on two human cancerous cell lines (bladder carcinoma J82 cells and epidermoid carcinoma KB 3-1 cells). Three cellular parameters were studied, viz., the qualitative effect on cellular microtubules, the quantitation of tubulin, and the antimitotic action, using two-parametric flow-cytometric analyses in treated cells. In both of the cell lines the tubulin content increased after taxoid treatment before the accumulation of cells in the G2/M phase. The effects of taxoids on tubulin appeared at about a 10-fold lower concentration on KB cells than on J82 cells. After drug exposure, the microtubule network showed a striking difference between the two cell lines: microtubule bundles were predominant in the J82 cell line, whereas multiple asters were prevalent in the KB cell line. The formation of these structures was dose- and time-dependent. Asters were observed in mitotic cells and bundles were seen in interphase cells. The reversibility of these structures in both cell lines varied with the duration of exposure to drug. Some differences were shown between taxol and Taxotere: the effects of Taxotere as compared with taxol appeared at a 2-fold lower concentration and their reversibility was slower.