Cyclin-dependent kinase 7 （Cdk7） is the catalytic subunit of the metazoan Cdk-activating kinase （CAK）. Activation of Cdk7 requires its association with a regulatory subunit, Cyclin H. Although the Cdk7/Cyclin H co...Cyclin-dependent kinase 7 （Cdk7） is the catalytic subunit of the metazoan Cdk-activating kinase （CAK）. Activation of Cdk7 requires its association with a regulatory subunit, Cyclin H. Although the Cdk7/Cyclin H complex has been implicated in the regulation ofRNA polymerase in several species, the precise function of their orthologs in zebrafish has not been fully elucidated. In this study, we isolated from zebrafish blastula embryos two cDNAs encoding the orthologs of human Cyclin H and Cdk7, and examined the role of Cdk7/Cyclin H in zebrafish embryogenesis. Sequence analysis showed that the zebrafish Cyclin H and Cdk7 cDNAs encode proteins with 65% and 86% identity to the respective hu- man orthologs. RT-PCR and whole-mount in situ hybridization analyses of their expression in unfertilized eggs, embryos and organs of adult fish suggested that Cyclin H and Cdk7 messages are maternally loaded. Our data also showed that their transcripts were detected throughout development. Distribution of Cyclin H transcripts was found to be ubiquitous during early stages of development and become restricted to the anterior neural tube, brain, eyes, procreate tissues, liver and heart by 5 days post-fertilization. Expression of a dominant-negative form of Cyclin H delayed the onset of zygotic transcription in the early embryo, resulting in apoptosis at 5 hours post-fertilization and leading to sever defects in tis- sues normally exhibiting high levels of Cyclin H expression. These results implicate Cyclin H in the regulation of the transcriptional machinery during midblastula transition and suggest that it is an essential gene in early zebrafish larval development.展开更多
Traditional therapies such as surgery and endocrine therapy no longer meet the clinical needs in prostate cancer treatment,and more effective treatments are urgently required.Recent studies have reported that targeted...Traditional therapies such as surgery and endocrine therapy no longer meet the clinical needs in prostate cancer treatment,and more effective treatments are urgently required.Recent studies have reported that targeted inhibition of the transcription factor cyclin dependent kinase 7(CDK7)could effectively suppress prostate cancer progression.However,the toxicity of CDK7 inhibitors such as THZ1 is the main limitation of the clinical application.In this work,we synthesized Cys8E(C8E)nanoparticles(NPs)loaded with THZ1(C8E@THZ1),a novel GSH-targeting and stimuli-responsive nano-delivery platform,and investigated its anti-tumor potential and biosafety properties.In vitro,C8E@THZ1 potently inhibited the proliferation and promoted the apoptosis of prostate cancer cells.On tumor-bearing mice,C8E@THZ1 inhibited tumors by up to 85%,while the damage of THZ1 to liver function was effectively avoided.These results confirmed that inhibition of CDK7 can effectively block the progression of prostate cancer,and that Cys8E NPs is a highly prospective delivery platform to promote the clinical application of CDK7 inhibitors.展开更多
文摘Cyclin-dependent kinase 7 （Cdk7） is the catalytic subunit of the metazoan Cdk-activating kinase （CAK）. Activation of Cdk7 requires its association with a regulatory subunit, Cyclin H. Although the Cdk7/Cyclin H complex has been implicated in the regulation ofRNA polymerase in several species, the precise function of their orthologs in zebrafish has not been fully elucidated. In this study, we isolated from zebrafish blastula embryos two cDNAs encoding the orthologs of human Cyclin H and Cdk7, and examined the role of Cdk7/Cyclin H in zebrafish embryogenesis. Sequence analysis showed that the zebrafish Cyclin H and Cdk7 cDNAs encode proteins with 65% and 86% identity to the respective hu- man orthologs. RT-PCR and whole-mount in situ hybridization analyses of their expression in unfertilized eggs, embryos and organs of adult fish suggested that Cyclin H and Cdk7 messages are maternally loaded. Our data also showed that their transcripts were detected throughout development. Distribution of Cyclin H transcripts was found to be ubiquitous during early stages of development and become restricted to the anterior neural tube, brain, eyes, procreate tissues, liver and heart by 5 days post-fertilization. Expression of a dominant-negative form of Cyclin H delayed the onset of zygotic transcription in the early embryo, resulting in apoptosis at 5 hours post-fertilization and leading to sever defects in tis- sues normally exhibiting high levels of Cyclin H expression. These results implicate Cyclin H in the regulation of the transcriptional machinery during midblastula transition and suggest that it is an essential gene in early zebrafish larval development.
基金supported by the National Key R&D Plan of China(No.2022YFC3602904)the National Natural Science Foundation of China(Nos.81974395,82173036)+11 种基金Guangdong Basic and Applied Basic Research Foundation(No.2019A1515011437)International Science and Technology Cooperation Project Plan of Guangdong Province(No.2021A0505030085)Sun Yat-Sen University Clinical Research 5010 Program(No.2019005)Beijing Bethune Charitable Foundation(No.mnzl202001)Guangzhou Science and Technology Key R&D Project(No.202206010117)Beijing CSCO Clinical Oncology Research Foundation(Nos.Ytongshu2021/ms-0162,Y-MSDZD2022-0760)Guangdong Province Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation(No.2020B1212060018OF006)Guangdong Provincial Clinical Research Center for Urological Diseases(No.2020B1111170006)supported by the National Natural Science Foundation of China(Nos.52173150,51973243)supported by the National Natural Science Foundation of China(No.82173088)Natural Science Foundation of Guangdong(No.2022A1515012383)the Guangzhou Science and Technology Fund(No.A202201011299)
文摘Traditional therapies such as surgery and endocrine therapy no longer meet the clinical needs in prostate cancer treatment,and more effective treatments are urgently required.Recent studies have reported that targeted inhibition of the transcription factor cyclin dependent kinase 7(CDK7)could effectively suppress prostate cancer progression.However,the toxicity of CDK7 inhibitors such as THZ1 is the main limitation of the clinical application.In this work,we synthesized Cys8E(C8E)nanoparticles(NPs)loaded with THZ1(C8E@THZ1),a novel GSH-targeting and stimuli-responsive nano-delivery platform,and investigated its anti-tumor potential and biosafety properties.In vitro,C8E@THZ1 potently inhibited the proliferation and promoted the apoptosis of prostate cancer cells.On tumor-bearing mice,C8E@THZ1 inhibited tumors by up to 85%,while the damage of THZ1 to liver function was effectively avoided.These results confirmed that inhibition of CDK7 can effectively block the progression of prostate cancer,and that Cys8E NPs is a highly prospective delivery platform to promote the clinical application of CDK7 inhibitors.
