[In vitro pharmacodynamic studies of novel class Ⅰ and Ⅱb selective histone deacetylase inhibitor purinostat mesylate in the treatment of diffuse large B-cell lymphoma and its mechanism].

Objective: To investigate the in vitro inhibitory activity of a novel class Ⅰ and Ⅱb selective histone deacetylase (HDAC) inhibitor, purinostat mesylate (PM) , in diffuse large B-cell lymphoma and its mechanism. Methods: The 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyl tetrazolium bromide method was used to detect the effect of PM on cell proliferation. The effects of PM on cell cycle and apoptosis were detected by flow cytometry. The acetylation levels of HDAC substrate, cell cycle protein, apoptosis-related protein, and oncogene protein expression were detected by Western blot. Results: PM significantly inhibited the proliferation of lymphoma SUDHL-4 and SUDHL-6 cells and increased the acetylation levels of HDAC substrates H3, H4, and α-tubulin. In cell cycle experiments, PM induced G(0)/G(1) phase arrest in SUDHL-4 and SUDHL-6 cells. Western blot experiment showed that PM could significantly downregulate the expression of cyclin-dependent kinases Cdk2, Cdk4, Cdk6, cyclin D1, and cyclin E and upregulate the expression of CDK inhibitor protein p21. In the apoptosis experiment, PM could induce the apoptosis of SUDHL-4 and SUDHL-6 cells. Western blot experiment demonstrated that PM promoted endogenous apoptosis by activating caspase-3 kinase and affecting antiapoptotic protein Bcl-2. In addition, PM could downregulate the expression of oncogene marker proteins MYC, IKZF1, and IKZF3. Conclusion: PM has an efficient biological activity in vitro for diffuse large B-cell lymphoma, including double-hit lymphoma, and provides valuable experimental evidence for PM in clinical treatment.