Objective： To investigate the effect of berberine, one of the main alkaloids of Rhizoma coptidis, on myocardial morphology and the expressions of cyclin-dependent kinase 9 （Cdk9） and cyclin T1 protein in the myocar...Objective： To investigate the effect of berberine, one of the main alkaloids of Rhizoma coptidis, on myocardial morphology and the expressions of cyclin-dependent kinase 9 （Cdk9） and cyclin T1 protein in the myocardium of type 2 diabetic rats. Methods： Type 2 diabetes mellitus rats were induced by an injection of 35 mg/kg streptozotocin （STZ） and a high-carbohydrate/high-fat diet for 16 weeks. Diabetic rats were given low-, middle-, high-dose berberine （75, 150, 300 mg/kg）, fenofibrate （100 mg/kg） and rosiglitazone （4 mg/kg） for another 16 weeks, respectively. The myocardium structure was observed with hematoxylin ＆ eosin （H＆E） staining and Cdk9 and cyclin T1 protein expressions were detected by immunohistochemistry. Results： Middle-dose, high-dose berberine improved myocardial hypertrophy and interstitial fibrosis of diabetic rats. Cdk9 and cyclin T1 protein were significantly lower in diabetic myocardium than in control one （P〈0.01）, and middle-dose, high-dose berberine and fenofibrate obviously increased both Cdk9 and cyclin T1 expression to near control level （P〈0.01）. Conclusion： Berberine modulates Cdk9 and cyclin T1 protein expression in diabetic myocardium which may contribute to ameliorate myocardium damage.展开更多
Human cytomegalovirus(HCMV)is a ubiquitous pathogen belongs to betaherpesvirus subfamily.RNA2.7 is a highly conserved long non-coding RNA accounting for more than 20%of total viral transcripts.In our study,functions o...Human cytomegalovirus(HCMV)is a ubiquitous pathogen belongs to betaherpesvirus subfamily.RNA2.7 is a highly conserved long non-coding RNA accounting for more than 20%of total viral transcripts.In our study,functions of HCMV RNA2.7 were investigated by comparison of host cellular transcriptomes between cells infected with HCMV clinical strain and RNA2.7 deleted mutant.It was demonstrated that RNA polymeraseⅡ(PolⅡ)-dependent host gene transcriptions were significantly activated when RNA2.7 was removed during infection.A145 nt-in-length motif within RNA2.7 was identified to inhibit the phosphorylation of PolⅡSerine-2(PolⅡS2)by reducing the interaction between PolⅡand phosphorylated cyclin-dependent kinase 9(pCDK9).Due to the loss of PolⅡS2 phosphorylation,cellular DNA pre-replication complex(pre-RC)factors,including Cdt1 and Cdc6,were significantly decreased,which prevented more cells from entering into S phase and facilitated viral DNA replication.Our results provide new insights of HCMV RNA2.7 functions in regulation of host cellular transcription.展开更多
The aberrant overexpression of cyclin-dependent kinase 9 (CDK9) in cancer cells results in the loss of proliferative control, making it an attractive therapeutic target for various cancers. However, the highly structu...The aberrant overexpression of cyclin-dependent kinase 9 (CDK9) in cancer cells results in the loss of proliferative control, making it an attractive therapeutic target for various cancers. However, the highly structural similarity between CDK9 and CDK2 makes the development of novel selective CDK9 inhibitors a challenging task and thus limits their clinical applications. Here, an effective two-stage virtual screening strategy was developed to identify novel CDK9 inhibitors with better inhibitory activity and higher selectivity. The first screening stage aims to select potential compounds with better inhibitory activity than Roniciclib, one of the most effective CDK9 inhibitors, through reliable structure-based pharmacophoric virtual screening and accurate molecular docking analyses. The second stage employs a very detailed visual inspection process, in which several structural criteria describing the major difference between the binding pockets of CDK9 and CDK2 are taken into consideration, to identify compounds with higher selectivity than CAN508, one of the CDK9 inhibitors with distinguished selectivity. Finally, three compounds (NCI207113 from NCI database and TCM0004 and TCM3282 from TCM database) with better inhibitory activity and higher selectivity were successfully identified as novel CDK9 inhibitors. These three compounds also display excellent binding stabilities, great pharmacokinetic properties and low toxicity in MD simulations and ADMET predictions. Besides, the results of binding free energy calculations suggest that enhancing van der Waals interaction and nonpolar solvation energy and/or reducing polar solvation energy can significantly improve the binding affinity of these CDK9 inhibitors. Their clinical potentials to serve as anticancer drug candidates can be further evaluated through a series of <em>in vitro/in vivo</em> bioassays in the future. To the best of our knowledge, this is the first attempt to identify novel CDK9 inhibitors with both better inhibitory activity and higher selectivity through an effective two-stage virtual screening strategy.展开更多
Cyclin-dependent kinase 9(CDK9)is a member of the transcription CDK subfamily and plays a role in transcriptional regulation.Selective CDK9 degraders possess potent clinical advantages over reversible CDK9 inhibitors....Cyclin-dependent kinase 9(CDK9)is a member of the transcription CDK subfamily and plays a role in transcriptional regulation.Selective CDK9 degraders possess potent clinical advantages over reversible CDK9 inhibitors.Herein,we report the first ATG101-recruiting selective CDK9 degrader,AZ-9,based on the hydrophobic tag kinesin degradation technology.AZ-9 showed significant degradation effects and selectivity toward other homologous cell cycle CDKs in vitro and in vivo,which could also affect downstream related phenotypes.Mechanism research revealed that AZ-9 recruits ATG101 to initiate the autophagy–lysosome pathway,and forms autophagosomes through the recruitment of LC3,which then fuses with lysosomes to degrade CDK9 and the partner protein Cyclin T1.These dates validated the existence of non-proteasomal degradation pathway of hydrophobic driven protein degradation strategy for the first time,which might provide research ideas for chemical induction intervention on other types of pathogenic proteins.展开更多
Targeted protein degrader has emerged as a transformative therapeutic technology,offering a novel modality to address previously intractable drug targets and enabling innovative approaches to disease treatment1.Unlike...Targeted protein degrader has emerged as a transformative therapeutic technology,offering a novel modality to address previously intractable drug targets and enabling innovative approaches to disease treatment1.Unlike conventional small-molecule drugs that function through occupancy-driven mechanisms,targeted protein degradation(TPD)employs an event-driven pharmacological strategy by harnessing the ubiquitin–proteasome system(UPS)and lysosomal degradation pathways2.展开更多
Venetoclax,an FDA-approved Bcl-2 selective inhibitor for the treatment of chronic lymphocytic leukemia and acute myeloid leukemia(AML),is tolerated well in elderly patients with AML and has good overall response rates...Venetoclax,an FDA-approved Bcl-2 selective inhibitor for the treatment of chronic lymphocytic leukemia and acute myeloid leukemia(AML),is tolerated well in elderly patients with AML and has good overall response rates;however,resistance remains a concern.In this study,we show that targeting CDK9 with voruciclib in combination with venetoclax results in synergistic antileukemic activity against AML cell lines and primary patient samples.CDK9 inhibition enhances venetoclax activity through downregulation of Mcl-1 and c-Myc.However,downregulation of Mcl-1 is transient,which necessitates an intermittent treatment schedule to allow for repeated downregulation of Mcl-1.Accordingly,an every other day schedule of the CDK9 inhibitor is effective in vitro and in vivo in enhancing the efficacy of venetoclax.Our preclinical data provide a rationale for an intermittent drug administration schedule for the clinical evaluation of the combination treatment for AML.展开更多
文摘Objective： To investigate the effect of berberine, one of the main alkaloids of Rhizoma coptidis, on myocardial morphology and the expressions of cyclin-dependent kinase 9 （Cdk9） and cyclin T1 protein in the myocardium of type 2 diabetic rats. Methods： Type 2 diabetes mellitus rats were induced by an injection of 35 mg/kg streptozotocin （STZ） and a high-carbohydrate/high-fat diet for 16 weeks. Diabetic rats were given low-, middle-, high-dose berberine （75, 150, 300 mg/kg）, fenofibrate （100 mg/kg） and rosiglitazone （4 mg/kg） for another 16 weeks, respectively. The myocardium structure was observed with hematoxylin ＆ eosin （H＆E） staining and Cdk9 and cyclin T1 protein expressions were detected by immunohistochemistry. Results： Middle-dose, high-dose berberine improved myocardial hypertrophy and interstitial fibrosis of diabetic rats. Cdk9 and cyclin T1 protein were significantly lower in diabetic myocardium than in control one （P〈0.01）, and middle-dose, high-dose berberine and fenofibrate obviously increased both Cdk9 and cyclin T1 expression to near control level （P〈0.01）. Conclusion： Berberine modulates Cdk9 and cyclin T1 protein expression in diabetic myocardium which may contribute to ameliorate myocardium damage.
基金supported by the National Natural Science Foundation of China(82071664)。
文摘Human cytomegalovirus(HCMV)is a ubiquitous pathogen belongs to betaherpesvirus subfamily.RNA2.7 is a highly conserved long non-coding RNA accounting for more than 20%of total viral transcripts.In our study,functions of HCMV RNA2.7 were investigated by comparison of host cellular transcriptomes between cells infected with HCMV clinical strain and RNA2.7 deleted mutant.It was demonstrated that RNA polymeraseⅡ(PolⅡ)-dependent host gene transcriptions were significantly activated when RNA2.7 was removed during infection.A145 nt-in-length motif within RNA2.7 was identified to inhibit the phosphorylation of PolⅡSerine-2(PolⅡS2)by reducing the interaction between PolⅡand phosphorylated cyclin-dependent kinase 9(pCDK9).Due to the loss of PolⅡS2 phosphorylation,cellular DNA pre-replication complex(pre-RC)factors,including Cdt1 and Cdc6,were significantly decreased,which prevented more cells from entering into S phase and facilitated viral DNA replication.Our results provide new insights of HCMV RNA2.7 functions in regulation of host cellular transcription.
文摘The aberrant overexpression of cyclin-dependent kinase 9 (CDK9) in cancer cells results in the loss of proliferative control, making it an attractive therapeutic target for various cancers. However, the highly structural similarity between CDK9 and CDK2 makes the development of novel selective CDK9 inhibitors a challenging task and thus limits their clinical applications. Here, an effective two-stage virtual screening strategy was developed to identify novel CDK9 inhibitors with better inhibitory activity and higher selectivity. The first screening stage aims to select potential compounds with better inhibitory activity than Roniciclib, one of the most effective CDK9 inhibitors, through reliable structure-based pharmacophoric virtual screening and accurate molecular docking analyses. The second stage employs a very detailed visual inspection process, in which several structural criteria describing the major difference between the binding pockets of CDK9 and CDK2 are taken into consideration, to identify compounds with higher selectivity than CAN508, one of the CDK9 inhibitors with distinguished selectivity. Finally, three compounds (NCI207113 from NCI database and TCM0004 and TCM3282 from TCM database) with better inhibitory activity and higher selectivity were successfully identified as novel CDK9 inhibitors. These three compounds also display excellent binding stabilities, great pharmacokinetic properties and low toxicity in MD simulations and ADMET predictions. Besides, the results of binding free energy calculations suggest that enhancing van der Waals interaction and nonpolar solvation energy and/or reducing polar solvation energy can significantly improve the binding affinity of these CDK9 inhibitors. Their clinical potentials to serve as anticancer drug candidates can be further evaluated through a series of <em>in vitro/in vivo</em> bioassays in the future. To the best of our knowledge, this is the first attempt to identify novel CDK9 inhibitors with both better inhibitory activity and higher selectivity through an effective two-stage virtual screening strategy.
基金supported by Key R&D Program of Shandong Province,China(No.2024CXPT028)National Natural Science Foundation of China(22177079,22477085)+2 种基金National Natural Science Foundation of Shanghai Province,China(No.24ZR1477400)National Natural Science Foundation of Shandong Province,China(No.ZR2024QC286)Taishan Scholar Foundation of Shandong Province(tstp0648,China).
文摘Cyclin-dependent kinase 9(CDK9)is a member of the transcription CDK subfamily and plays a role in transcriptional regulation.Selective CDK9 degraders possess potent clinical advantages over reversible CDK9 inhibitors.Herein,we report the first ATG101-recruiting selective CDK9 degrader,AZ-9,based on the hydrophobic tag kinesin degradation technology.AZ-9 showed significant degradation effects and selectivity toward other homologous cell cycle CDKs in vitro and in vivo,which could also affect downstream related phenotypes.Mechanism research revealed that AZ-9 recruits ATG101 to initiate the autophagy–lysosome pathway,and forms autophagosomes through the recruitment of LC3,which then fuses with lysosomes to degrade CDK9 and the partner protein Cyclin T1.These dates validated the existence of non-proteasomal degradation pathway of hydrophobic driven protein degradation strategy for the first time,which might provide research ideas for chemical induction intervention on other types of pathogenic proteins.
文摘Targeted protein degrader has emerged as a transformative therapeutic technology,offering a novel modality to address previously intractable drug targets and enabling innovative approaches to disease treatment1.Unlike conventional small-molecule drugs that function through occupancy-driven mechanisms,targeted protein degradation(TPD)employs an event-driven pharmacological strategy by harnessing the ubiquitin–proteasome system(UPS)and lysosomal degradation pathways2.
文摘Venetoclax,an FDA-approved Bcl-2 selective inhibitor for the treatment of chronic lymphocytic leukemia and acute myeloid leukemia(AML),is tolerated well in elderly patients with AML and has good overall response rates;however,resistance remains a concern.In this study,we show that targeting CDK9 with voruciclib in combination with venetoclax results in synergistic antileukemic activity against AML cell lines and primary patient samples.CDK9 inhibition enhances venetoclax activity through downregulation of Mcl-1 and c-Myc.However,downregulation of Mcl-1 is transient,which necessitates an intermittent treatment schedule to allow for repeated downregulation of Mcl-1.Accordingly,an every other day schedule of the CDK9 inhibitor is effective in vitro and in vivo in enhancing the efficacy of venetoclax.Our preclinical data provide a rationale for an intermittent drug administration schedule for the clinical evaluation of the combination treatment for AML.
