Paclitaxel induces apoptosis in leukemia cells through a JNK activation-dependent pathway.

Paclitaxel induces apoptosis in leukemia cells through a JNK activation-dependent pathway. Genet Mol Res. 2016;15(1) Authors: Peng ZG, Liu DC, Yao YB, Feng XL, Huang X, Tang YL, Yang J, Wang XX Abstract Paclitaxel (PTX) is a mitotic inhibitor widely used in chemotherapy for many types of cancers, including solid tumors and hematological malignancies. However, the molecular basis of the anti-proliferation activity of PTX is not fully understood. In this paper, we focused on the role of c-Jun N-terminal kinase (JNK) pathways in PTX-induced apoptosis and proliferation inhibition. The effects of PTX were examined in human leukemia cell lines and patients' chronic lymphocytic leukemia (CLL) cells in relation to mitochondrial events, apoptosis, and perturbation of JNK activation using flow cytometry, siRNA, mitochondrial membrane potential determination, and western blotting. Exposure of cells to PTX at concentrations ≥10 nM for 18 or 24 h resulted in a significant release of cytochrome c from mitochondria to the cytosol, cleavages of procaspase 3 and poly (ADP-ribose) polymerase (PARP), and JNK activation, leading to apoptosis. The pan-caspase inhibitor BOC-D-FMK blocked the PTX-induced apoptosis but had no effect on cytochrome c release, suggesting that cytochrome c had been released before caspase activation. Moreover, both pharmacological JNK inhibitors SP600125 and JNK siRNA dramatically blocked PTX-induced apoptosis, cytochrome c r...
Source: Genetics and Molecular Research - Category: Genetics & Stem Cells Authors: Tags: Genet Mol Res Source Type: research