Background & objective: Cell cycle specificity, an important feature of anticancer drugs, is commonly used in the design of combined chemotherapy. Paclitaxel is widely accepted as an G2/M phase-specific agent. However, cumulative evidences revealed that the cell cycle specificity of anticancer drugs in vitro is not always consistent as in vivo. This study was to observe the effect of paclitaxel on the cell cycle specificity in different cell models.
Methods: Effects of paclitaxel on cell apoptosis of human lymphocyte leukemia cell line Molt-4 and 17 clinical specimens of acute leukemia were investigated using flow cytometry.
Results: Paclitaxel induced G2/M phase-specific apoptosis in exponentially growing Molt-4 cells, G0/G1 phase-specific apoptosis in high-density cultured Molt-4 cells, and S phase-specific apoptosis in acute leukemia specimens.
Conclusions: Paclitaxel exhibits different cell-cycle specificity in different models. Different from other studies, paclitaxel induces S phase-specific apoptosis in clinical leukemia specimens. This difference is most likely related to the growing status of the target cells.