Effect Of Mitochondrial Autophagy Pathway In The Parthenolide-induced Apoptosis Of Gastrointestinal Stromal Cells

OBJECTIVE:To investigate the effect of mitochondrial autophagy on the apoptosis of ginical gastrointestinal stromal tumor cells induced by parthenolide and its possible mechanism.METHODS:Human GIST-882 cells were selected for culture in vitro.MTT assay was used to determine the inhibitory rate of different concentrations of PTL on GIST cell proliferation.The IC50 concentration of PTL against proliferation of GIST-882 cells was selected and used as an experimental group for the following experiments.Flow cytometry was used to evaluate the early apoptosis rate of GIST cells,JC-1 experiment was used to detect the changes of mitochondrial membrane potential.The morphological changes of GIST cells were observed by transmission electron microscope.The expression of Bcl-2 and Bax apoptosis-associated proteins,the expression of Beelinel and LC3?/? autophagy-related proteins,and the mitochondrial autophagy-related protein Pinkl were determine by Western blotting.RESULTS:The results of MTT assay showed that PTL could inhibit the proliferation of GIST cells(P<0.05),and the inhibition rate increased with the PTL concentration increase.The flow cytometry mothod showed that PTL could promote the apoptosis rate of GIST cells.When combined with autophagy inhibitor 3-MA,it significantly reduced the apoptotic rate of PTL(P<0.05).The GIST cells treated with PTL for 24 hours then its' mitochondria were observed by JC-1 mothod.The membrane potential of the mitochondria were reduced and emitted green fluorescence,and the cells tended to apoptosis.Autophagosomes apperence after treatment with PTL for 24h were observerd by transmission electron microscope.The cell scratch mothod showed that the migration ability was lower in the PTL group than that in control group(P<0.05).The results of western blot showed that the expression levels of apoptosis inhibitory bcl-2 was decreased,the expression of bax was increased(P<0.05).The expression levels of autophagic markers,LC3?/? and Beeline l were both increased(P<0,05).PTL increased the experession of PINKl(mito),and decreased the expression of PINK1(cyto)(P<0.05).CONCLUSION:1.PTL have induced apoptosis and autophagy of GIST cell.2.The GIST apoptosis induced by PTL through the Mitophagy pathway.