| Purpose: Diffuse large B-cell lymphoma(DLBCL)is the most common subtype of lymphoma,with poor outcome in approximately 30%to 40% of patients.Therefore,there is an urgent need to explore new therapeutic strategies to improve the prognosis of patients with relapsed/refractory DLBCL.Studies have shown that targeted HDAC is effective in patients with B-cell lymphoma.This study aims to investigate the role and mechanism of HS270,a novel HDAC inhibitor,in DLBCL and provide a pre-study basis for clinical treatment.Methods:1.The effect of HS270 on the proliferation of DLBCL cell lines was examined by CCK8 assay.The effect of HS270 on DLBCL cell apoptosis and cell cycle was detected by flow cytometry.RNA transcriptomics sequencing of HS270-treated DLBCL cells was validated using q RT-PCR to identify the target genes affected by HS270.2.The expression of MYBL2 in DLBCL was explored through public database bioinformatics analysis,cell level research and clinical tissue sample analysis,and the correlation with prognosis and clinical features was analyzed.3.The expression levels of TP53,P21 and MYBL2 were detected by Western Blot.It was to verify the target of HS270 by MYBL2 knocked down and TP53 activator.The effect of HS270 on cellular and tumor tissue senescence was detected by β-galactosidase.The xenografts was HS270’s inhibitory effect on DLBCL in vivo and its effect on TP53/P21/MYBL2 axis.Results:1.HS270 significantly inhibited DLBCL cell proliferation,induced apoptosis and blocked cell cycle.Analysis of validated RNA sequencing results revealed that HS270 significantly affected the transcriptomic changes in cellular senescence pathway,and the expression of MYBL2 in senescence pathway was significantly reduced.2.Bioinformatics database analysis revealed that MYBL2 protein levels in lymph nodes of DLBCL patients was higher than that in normal lymph nodes,and the MYBL2 protein levels had a negative correlation with the prognosis of DLBCL.The results of the clinical samples study were consistent with the bioinformatics results,and indicated that the high expression of MYBL2 was an independent prognostic factor affecting OS of DLBCL patients,and MYBL2 protein was correlated with the Ki-67 level,Ann Arbor staging and other clinical features in DLBCL.The m RNA and protein expression levels of MYBL2 were higher in the DLBCL cell lines than in the immortalized B cells.3.In vitro and in vivo experiments demonstrated that HS270 induced a decrease in m RNA and protein level expression of MYBL2 and TP53,an increase in P21 expression,and promoted cellular senescence in DLBCL cells.The rescue experiment showed that HS270 might play a role in inhibiting the progression of diffuse large B-cell lymphoma by down-regulating MYBL2.Conclusion: HS270 can exert anti-DLBCL effects by inducing DLBCL cell senescence through down-regulation of MYBL2,which may be an important effector molecule of HS270.HS270 may be a new therapeutic strategy for DLBCL. |
