Inhibitation Of Proliferation And Regulation Of Histone Acetylation On Acute T Lymphoblastic Leukemia Cells Jurkat And Multiple Myeloma Cells U266 With Valproic Acid Sodium

Objective To study cell proliferation inhibition and cell cycle effects of valproic acid sodium (VPA) in vitro on Jurkat cells and U266 cells; to observe the impact of VPA on histone deacetylase 1 (HDAC1) and histone acetylation modification regulation, and the initial study of the linkages between the occurrence or development of leukemia or multiple myeloma and epigenetics, which further clarify the possible mechanisms in the occurrence or development of leukemia and multiple myeloma. To observe the role and regulation of apoptosis-related gene transcription level with VPA on Jurkat cells and U266 cells, and to explore possible ways of apoptosis. In addition, to further study inhibition of the original generation cell proliferation and regulation of histone acetylating modification with VPA, and inducing the re-expression of related genes.Method The CCK-8 assay, growth curve as well as clone formation inhibition ratio methods were used to evaluate the effect that VPA had on the ability of cell reduplication and cell vitality. The Hoechst 33258 fluorescent dyes, the DNA gel electrophoresis were used to observe the situation of cell apoptosis. Jurkat cells and U266 cells treated with VPA were detected cell cycle and apoptosis ratio changes by flow cytometry. Histone deacetylase 1 (HDAC1), p21waf1/cip1, p27kip1, c-myc, survivin mRNA expression changes were detected by semi-quantitative RT-PCR. The protein levels of HDAC1, histone H3/H4 acetylation and procaspase-3, procaspase-9 were detected by Western blot. Similarly the impact of VPA on the original generation cell were detected. Results (1) VPA can inhibit the proliferation of Jurkat cells and U266 cells in a time-concentration-dependent; the inhibition of cell proliferation and colony formation was observed under light microscopy after VPA treated. (2) After Jurkat cells and U266 cells treated with VPA for 48h, cell-cycle tests showed that the proportion of G0/G1 phase increased and S phase fraction decreased. The cells were arrested in G0/G1 phase. (3) Compared with the untreated group, after Jurkat cells and U266 cells treated with VPA for 48h, HDAC1 mRNA and protein decreased, while histone H3, H4 acetylation protein increased. (4) Compared with the untreated group, Jurkat cells and U266 cells treated with VPA for 48h were detected that apoptosis increased and nuclear stain were dense by the Hoechst 33258 fluorescence staining; a typical DNA ladder by DNA gel electrophoresis; apoptosis ratio increased by flow cytometry. (5) After Jurkat cells and U266 cells treated with VPA for 48h, p21waf1/cip1, p27kip1 mRNA expression increased, while c-myc, survivin mRNA expression decreased, procaspase-3, procaspase-9 protein expression also reduced. (6) After the primary ALL cells treated with VPA, we can see that cell proliferation was inhibited in a time-concentration-dependent. Treated with VPA for 48h, HDAC1 mRNA and protein decreased, while histone H3, H4 acetylation protein increased; p21waf1/cip1, p27kip1 mRNA expression increased, while c-myc, survivin mRNA expression decreased.Conclusions (1) VPA in vitro can inhibit the proliferation of Jurkat cells and U266 cells, block cell cycle at the G0/G1 phase, promote cell apoptosis and regulate gene expression, which may be related to VPA inhibited HDAC1 expression and increased histone H3, H4 acetylation level. (2) VPA in vitro can inhibit the proliferation of primary ALL cells, reduce HDAC1 mRNA expression, increase histone H3, H4 acetylation protein levels, and regulate the related gene expression. This will provide some theoretical basis for VPA in the treatment of leukemia in the future.