Paclitaxel-induced Apoptosis In Human Esophageal Carcinoma Cell Line And The Proapoptotic Effect Of Bcl-2 Ribozyme

Paclitaxel is a novel anti-microtubule agent, which has a unique mechanism of action. Many studies have shown that the broad -spectrum anti-tumor effect of paclitaxel is correlated with its apoptosis-inducing activity. In the present study, the cytotoxic effect of paclitaxel on human esophageal carcinoma cell line Eca 109 was examined by MTT assay, cell morphology, gel electrophoresis of DNA, FCM. TUNEL and Annexin V assays. The results further confirmed that the cytotoxic effect of paclitaxel on Eca 109 cells is due to its proapoptotic activity. Owning to the unique action of paclitaxel on tubulin polymerization and mitotic arrest, a distinct apoptotic feature at mitosis was observed. The cell cycle block at G₂/M phase, however, is not a sufficient signal for paclitaxel-induced apoptosis, and might even inhibit the apoptotic process. Although the duration of detectable typical apoptotic feature was several hours after paclitaxel treatment, the results showed that it was rapid for paclitaxel binding to tubulin and triggered the signal transduction of cell apoptosis. FCM analysis revealed that the action of paclitaxel on Eca 109 cells was somewhat different from that on other kinds of cell lines. In...