Effects Of Demethylase KDM4A Inhibitor On Proliferation And Apoptosis Of Diffuse Large B Cell Lymphoma Cells

Objective: To study the expression of KDM4 A in diffuse large B-cell lymphoma cells.The effect of KDM4 A inhibitor NSC636819 on proliferation and apoptosis of SU-DHL-6 cell line in diffuse large B cell lymphoma was further identified,as the differences of PARP-1 and H3K36me3 protein expression and methylation.Methods: QPCR was used to detect the relative expression levels of KDM4 A in diffuse large B-cell lymphoma cells,and normal lymphocytes were used as the control to verify the existence of SU-DHL-6 differential expression.KDM4 A inhibitor NSC636819 was used to interfere with the SU-DHL-6 cell line in diffuse large B-cell lymphoma,and its effect on the proliferation and apoptosis of SU-DHL-6 was studied by using MTS and fluorescence microscopy.Western blot was used to detect whether the expression levels of PARP-1 and H3K36me3 were changed.Result:(1)KDM4A was highly expressed in both the ABC cell line SU-DHL-2 and the GCB cell line SU-DHL-6 in diffuse large B cell lymphoma.The difference was statistically significant(p<0.05).(2)NSC636819 inhibited the proliferation of SU-DHL-6 cells in a concentration-dependent manner.After 25μmol/L、50μmol/L、100μmol/L、200μmol/L、400μmol/L NSC636819 treatment for 24h、48h,IC50 is192.9μmol/L 、 120.3μmol/L respectively,the proliferation inhibition rate of SU-DHL-6 cells decreased.The difference was statistically significant(p<0.05).(3)NSC636819 may cause SU-DHL-6 apoptosis.After the cells were treated with NSC636819 with concentrations of 50μmol/L、100μmol/L、200μmol/L for 36 h,the untreated cells were used as the control group,the number and proportion of apoptotic cells(green fluorescence)increased,the cell proliferation was inhibited,and the cell growth density decreased.(4)After SU-DHL-6 cells were treated with NSC636819 with concentrations of 50μmol/L、100μmol/L、200μmol/L for 48 h,the relative expression of H3K36me3 increased,the relative protein expression of PARP-1decreased.The difference was statistically significant(p<0.05).Conclusions:(1)KDM4A is highly expressed in diffuse large B-cell lymphoma SU-DHL-2、SU-DHL-6 cells.(2)KDM4A inhibitor NSC636819 inhibits proliferation of diffuse large B-cell lymphoma SU-DHL-6 cell line in a concentration-dependent manner and may promote its apoptosis.Its mechanism of inhibiting proliferation and apoptosis may be related to up-regulation of H3K36 trimethylation level and down-regulation of apoptosis-related PARP-1 protein.