Mechanisms of oxaliplatin-induced apoptosis of human multiple myeloma cell RPMI8226 / 中国实验血液学杂志

ABSTRACT

This study was aimed to investigate the effects of oxaliplatin on human multiple myeloma cell line RPMI-8226 and its mechanism. The proliferation inhibitory rate of RPMI8226 cells was assayed by MTT, the morphological changes of RPMI-8226 cells were observed by inverted fluorescent microscopy and transmission electron microscopy, the apoptosis rate and the cell cycle distribution of RPMI-8226 cells were detected by flow cytometry, The effects of oxaliplatin on the expression of Bcl-2, caspase-8, caspase-3 mRNA were tested by RT-PCR, Bcl-2 protein expression of RPMI-8226 cells was analyzed by Western blot. The results showed that oxaliplatin could inhibit the proliferation of RPMI-8226 cells in time and dose-dependent manners. Cell number in oxaliplatin group was significantly less than that in control group under light microscope, and the growth arrangement was irregular, apoptotic cells could be seen. Under electron microscope, typical apoptotic morphological and ultrastructural changes could be observed. Flow cytometry results showed that oxaliplatin could induce apoptosis of RPMI-8226 cells, the difference have statistical significance (P < 0.05). Oxaliplatin mainly arrested RPMI-8226 cells in the S phase (P < 0.05). The expression of Bcl-2 mRNA did not have apparent change, while the expression of caspase-8, caspase-3 mRNA increased (P < 0.05). Western blot results suggested that the expression of Bcl-2 protein had no obvious change. It is concluded that the oxaliplatin can induce apoptosis of RPMI-8226 cells, activating the death receptor pathway and arresting cell cycle may be two of the related mechanisms, Bcl-2 gene has unobservable effects in the process of oxaliplatin-induced cell apoptosis.