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
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
MYC is an oncogenic transcription factor with a novel role in enhancing global transcription when overexpressed. However, how MYC promotes global transcription remains controversial. Here, we used a series of MYC muta...MYC is an oncogenic transcription factor with a novel role in enhancing global transcription when overexpressed. However, how MYC promotes global transcription remains controversial. Here, we used a series of MYC mutants to dissect the molecular basis for MYC-driven global transcription. We found that MYC mutants deficient in DNA binding or known transcriptional activation activities can still promote global transcription and enhance serine 2 phosphorylation(Ser2P) of the RNA polymerase(Pol) II Cterminal domain(CTD), a hallmark of active elongating RNA Pol II. Two distinct regions within MYC can promote global transcription and Ser2P of Pol II CTD. The ability of various MYC mutants to promote global transcription and Ser2P correlates with their ability to suppress CDK9 SUMOylation and enhance positive transcription elongation factor b(P-TEFb) complex formation. We showed that MYC suppresses CDK9 SUMOylation by inhibiting the interaction between CDK9 and SUMO enzymes including UBC9 and PIAS1. Furthermore, MYC's activity in enhancing global transcription positively contributes to its activity in promoting cell proliferation and transformation. Together, our study demonstrates that MYC promotes global transcription, at least in part, by promoting the formation of the active P-TEFb complex via a sequence-specific DNA-binding activity-independent manner.展开更多
Abnormally activated CDK9 participates in the super-enhancer mediated transcription of short-lived proteins required for cancer cell survival.Targeting CDK9 has shown potent anti-tumor activity in clinical trials amon...Abnormally activated CDK9 participates in the super-enhancer mediated transcription of short-lived proteins required for cancer cell survival.Targeting CDK9 has shown potent anti-tumor activity in clinical trials among different cancers.However,the study and knowledge on drug resistance to CDK9 inhibitors are very limited.In this study,we established an AML cell line with acquired resistance to a highly selective CDK9 inhibitor BAY1251152.Through genomic sequencing,we identified in the kinase domain of CDK9 a mutation L156F,which is also a coding SNP in the CDK9 gene.By knocking in L156F into cancer cells using CRISPR/Cas9,we found that single CDK9 L156F could drive the resistance to CDK9 inhibitors,not only ATP competitive inhibitor but also PROTAC degrader.Mechanistically,CDK9 L156F disrupts the binding with inhibitors due to steric hindrance,further,the mutation affects the thermal stability and catalytic activity of CDK9 protein.To overcome the drug resistance mediated by the CDK9-L156F mutation,we discovered a compound,IHMT-CDK9-36 which showed potent inhibition activity both for CDK9 WT and L156F mutant.Together,we report a novel resistance mechanism for CDK9 inhibitors and provide a novel chemical scaffold for the future development of CDK9 inhibitors.展开更多
This comprehensive review delves into the current updates and challenges associated with the management of low-grade gliomas(LGG),the predominant primary tumors in the central nervous system.With a general incidence r...This comprehensive review delves into the current updates and challenges associated with the management of low-grade gliomas(LGG),the predominant primary tumors in the central nervous system.With a general incidence rate of 5.81 per 100000,gliomas pose a significant global concern,necessitating advancements in treatment techniques to reduce mortality and morbidity.This review places a particular focus on immunotherapies,discussing promising agents such as Zotiraciclib and Lerapolturev.Zotiraciclib,a CDK9 inhibitor,has demonstrated efficacy in glioblastoma treatment in preclinical and clinical studies,showing its potential as a therapeutic breakthrough.Lerapolturev,a viral immunotherapy,induces inflammation in glioblastoma and displays positive outcomes in both adult and pediatric patients.Exploration of immunotherapy extends to Pembrolizumab,Nivolumab,and Entrectinib,revealing the challenges and variabilities in patient responses.Despite promising preclinical data,the monoclonal antibody Depatuxizumab has proven ineffective in glioblastoma treatment,emphasizing the critical need to understand resistance mechanisms.The review also covers the success of radiation therapy in pediatric LGG,with evolving techniques,such as proton therapy,showing potential improvements in patient quality of life.Surgical treatment is discussed in the context of achieving a balance between preserving the patient’s quality of life and attaining gross total resection,with the extent of surgical resection significantly influencing the survival outcomes.In addition to advancements in cancer vaccine development,this review highlights the evolving landscape of LGG treatment,emphasizing a shift toward personalized and targeted therapies.Ongoing research is essential for refining strategies and enhancing outcomes in the management of LGG.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.
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 the National Natural Science Foundation of China (32070643, 32130051, 31961133009)Science and Technology Commission of Shanghai Municipality (20JC1411500)+3 种基金the ECNU Public Platform for Innovation (011)the Instruments Sharing Platform of the School of Life Sciences,East China Normal Universitysupported by the US National Institutes of Health (NIH) grant 1RO1CA251698-01Cancer Prevention and Research Institute of Texas (CPRIT) grant RP190077。
文摘MYC is an oncogenic transcription factor with a novel role in enhancing global transcription when overexpressed. However, how MYC promotes global transcription remains controversial. Here, we used a series of MYC mutants to dissect the molecular basis for MYC-driven global transcription. We found that MYC mutants deficient in DNA binding or known transcriptional activation activities can still promote global transcription and enhance serine 2 phosphorylation(Ser2P) of the RNA polymerase(Pol) II Cterminal domain(CTD), a hallmark of active elongating RNA Pol II. Two distinct regions within MYC can promote global transcription and Ser2P of Pol II CTD. The ability of various MYC mutants to promote global transcription and Ser2P correlates with their ability to suppress CDK9 SUMOylation and enhance positive transcription elongation factor b(P-TEFb) complex formation. We showed that MYC suppresses CDK9 SUMOylation by inhibiting the interaction between CDK9 and SUMO enzymes including UBC9 and PIAS1. Furthermore, MYC's activity in enhancing global transcription positively contributes to its activity in promoting cell proliferation and transformation. Together, our study demonstrates that MYC promotes global transcription, at least in part, by promoting the formation of the active P-TEFb complex via a sequence-specific DNA-binding activity-independent manner.
基金supported by the National Natural Science Foundation of China(Grant Nos.81903650,32171479,82103976)the Natural Science Foundation of Anhui Province(Grant Nos.2008085MH274,2108085QH377,China)+2 种基金the Collaborative Innovation Program of Hefei Science Center,CAS(Grant No.2021HSC-CIP014,China)the CASHIPS Director’s Found(Grant Nos.YZJJZX202011,YZJJ2021QN38,China)supported by the High Magnetic Field Laboratory of Anhui Province。
文摘Abnormally activated CDK9 participates in the super-enhancer mediated transcription of short-lived proteins required for cancer cell survival.Targeting CDK9 has shown potent anti-tumor activity in clinical trials among different cancers.However,the study and knowledge on drug resistance to CDK9 inhibitors are very limited.In this study,we established an AML cell line with acquired resistance to a highly selective CDK9 inhibitor BAY1251152.Through genomic sequencing,we identified in the kinase domain of CDK9 a mutation L156F,which is also a coding SNP in the CDK9 gene.By knocking in L156F into cancer cells using CRISPR/Cas9,we found that single CDK9 L156F could drive the resistance to CDK9 inhibitors,not only ATP competitive inhibitor but also PROTAC degrader.Mechanistically,CDK9 L156F disrupts the binding with inhibitors due to steric hindrance,further,the mutation affects the thermal stability and catalytic activity of CDK9 protein.To overcome the drug resistance mediated by the CDK9-L156F mutation,we discovered a compound,IHMT-CDK9-36 which showed potent inhibition activity both for CDK9 WT and L156F mutant.Together,we report a novel resistance mechanism for CDK9 inhibitors and provide a novel chemical scaffold for the future development of CDK9 inhibitors.
文摘This comprehensive review delves into the current updates and challenges associated with the management of low-grade gliomas(LGG),the predominant primary tumors in the central nervous system.With a general incidence rate of 5.81 per 100000,gliomas pose a significant global concern,necessitating advancements in treatment techniques to reduce mortality and morbidity.This review places a particular focus on immunotherapies,discussing promising agents such as Zotiraciclib and Lerapolturev.Zotiraciclib,a CDK9 inhibitor,has demonstrated efficacy in glioblastoma treatment in preclinical and clinical studies,showing its potential as a therapeutic breakthrough.Lerapolturev,a viral immunotherapy,induces inflammation in glioblastoma and displays positive outcomes in both adult and pediatric patients.Exploration of immunotherapy extends to Pembrolizumab,Nivolumab,and Entrectinib,revealing the challenges and variabilities in patient responses.Despite promising preclinical data,the monoclonal antibody Depatuxizumab has proven ineffective in glioblastoma treatment,emphasizing the critical need to understand resistance mechanisms.The review also covers the success of radiation therapy in pediatric LGG,with evolving techniques,such as proton therapy,showing potential improvements in patient quality of life.Surgical treatment is discussed in the context of achieving a balance between preserving the patient’s quality of life and attaining gross total resection,with the extent of surgical resection significantly influencing the survival outcomes.In addition to advancements in cancer vaccine development,this review highlights the evolving landscape of LGG treatment,emphasizing a shift toward personalized and targeted therapies.Ongoing research is essential for refining strategies and enhancing outcomes in the management of LGG.
