Sensitivity to paclitaxel is not related to p53-dependent apoptosis in ovarian cancer cells.

We conducted this study to determine whether the sensitivity of ovarian cancer cells to paclitaxel (PTX) relates to cells undergoing p53-dependent apoptosis. Human ovarian adenocarcinoma cell lines (SK-OV-3, KF and KP cells) were used in this study. In SK-OV-3 and KP cells, which have a homozygous deletion of the TP53 gene, wild-type TP53 gene-transduction markedly enhanced the sensitivity to cisplatin (CDDP), but did not enhance the sensitivity to PTX. In all cells, the apoptotic index was increased by CDDP or PTX. After exposure to CDDP, p53 and Bax protein expression increased and Bcl-xL expression decreased in the KF cells and TP53 gene-transducted SK-OV-3 cells. However, these proteins did not change in KP cells. Therefore, the role of p53 in CDDP-induced apoptosis depends upon the cell type. In contrast, TP53 gene status did not correlate with PTX-induced cytotoxicity in any of the cell lines with differing apoptotic pathways. In conclusion, the sensitivity to PTX may not be related to p53-dependent apoptosis in ovarian cancer cells.