Apoptosis of multiple myeloma cells induced by gossypol acetic acid in vitro and its mechanism

This study was aimed to investigate the apoptosis effect of gossypol acetic acid on classic human multiple myeloma RPMI8226 cell line in vitro and its mechanism. The inhibitory effect on proliferation of RPMI8226 cells was evaluated by means of MTT assay. Cytotoxic effect and apoptosis was identified and analyzed with the aid of transmission electron microscopy,mitochondria membrane potential (MMP) and DNA gel electrophoresis. Meanwhile,Western-blot assay was used to detect the changes of several key cell apoptosis regulatory proteins such as BAX,caspase-3 and caspase-8 in these cells before and after treatment. The results showed that low concentrations of gossypol acetic acid (16 μmol/L) could suppress the proliferation and induce the apoptosis in RPMI8226 cells effectively. At the same time,gossypol acetic acid could also down-regulate the mitochondrial membrane potential,up-regulate the expression of the apoptosis-related protein such as BAX and caspase-3. It is concluded that the gossypol acetic acid can selectively induce proliferation inhibition and apoptosis of multiple meleloma RPMI8226 cells with a smaller dose.