COMPARATIVE EFFECTS OF TAXOL AND TAXOTERE ON 2 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 carc inoma KB 3-1 cells). Three cellular parameters were studied, viz., the qualitative effect on cellular microtubules, the quantitation of tubu lin, and the antimitotic action, using two-parametric flow-cytometric analyses in treated cells. In both of the cell lines the tubulin conte nt increased after taxoid treatment before the accumulation of cells i n the G(2)/M phase. The effects of taxoids on tubulin appeared at abou t a 10-fold lower concentration on KB cells than on J82 cells. After d rug exposure, the microtubule network showed a striking difference bet ween the two cell lines: microtubule bundles were predominant in the J 82 cell line, whereas multiple asters were prevalent in the KB cell li ne. The formation of these structures was dose- and time-dependent. As ters were observed in mitotic cells and bundles were seen in interphas e cells. The reversibility of these structures in both cell lines vari ed with the duration of exposure to drug. Some differences were shown between taxol and Taxotere: the effects of Taxotere as compared with t axol appeared at a 2-fold lower concentration and their reversibility was slower.