BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression result...BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression results in a loss of this capacity to facilitate cyclin E degradation.The ubiquitination and degradation of cyclin E1 may be associated with phosphorylation at specific sites on the protein,with Cx43 potentially enhancing this process by facilitating the phosphorylation of these critical residues.AIM To investigate the correlation between expression of Cx43,SKP1/Cullin1/F-box(SCF)FBXW7,p-cyclin E1(ser73,thr77,thr395)and clinicopathological indexes in colon cancer.METHODS Expression levels of Cx43,SCF^(FBXW7),p-cyclin E1(ser73,thr77,thr395)in 38 clinical colon cancer samples were detected by immunohistochemistry and were analyzed by statistical methods to discuss their correlations.RESULTS Positive rate of Cx43,SCF^(FBXW7),p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in detected samples were 76.32%,76.32%,65.79%,5.26%and 55.26%respectively.Positive expressions of these proteins were not related to the tissue type,degree of tissue differentiation or lymph node metastasis.Cx43 and SCF^(FBXW7)(r=0.749),p-cyclin E1(Ser73)(r=0.667)and p-cyclin E1(Thr395)(r=0.457),SCF^(FBXW7) and p-cyclin E1(Ser73)(r=0.703)and p-cyclin E1(Thr395)(0.415)were correlated in colon cancer(P<0.05),and expressions of the above proteins were positively correlated in colon cancer.CONCLUSION Cx43 may facilitate the phosphorylation of cyclin E1 at the Ser73 and Thr195 sites through its interaction with SCF^(FBXW7),thereby influencing the ubiquitination and degradation of cyclin E1.展开更多
Cancer is characterized by abnormal cell proliferation.Cyclins and cyclin-dependent kinases(CDKs)have been recognized as essential regulators of the intricate cell cycle,orchestrating DNA replication and transcription...Cancer is characterized by abnormal cell proliferation.Cyclins and cyclin-dependent kinases(CDKs)have been recognized as essential regulators of the intricate cell cycle,orchestrating DNA replication and transcription,RNA splicing,and protein synthesis.Dysregulation of the CDK pathway is prevalent in the development and progression of human cancers,rendering cyclins and CDKs attractive therapeutic targets.Several CDK4/6 inhibitors have demonstrated promising anti-cancer efficacy and have been successfully translated into clinical use,fueling the development of CDK-targeted therapies.With this enthusiasm for finding novel CDK-targeting anti-cancer agents,there have also been exciting advances in the field of targeted protein degradation through innovative strategies,such as using proteolysis-targeting chimera,heat shock protein 90(HSP90)-mediated targeting chimera,hydrophobic tag-based protein degradation,and molecular glue.With a focus on the translational potential of cyclin-and CDK-targeting strategies in cancer,this review presents the fundamental roles of cyclins and CDKs in cancer.Furthermore,it summarizes current strategies for the proteasome-dependent targeted degradation of cyclins and CDKs,detailing the underlying mechanisms of action for each approach.A comprehensive overview of the structure and activity of existing CDK degraders is also provided.By examining the structure‒activity relationships,target profiles,and biological effects of reported cyclin/CDK degraders,this review provides a valuable reference for both CDK pathway-targeted biomedical research and cancer therapeutics.展开更多
Dear Editor,Lung cancer is a major global health concern,with 2.2 million patients diagnosed in 2020.Non-small cell lung cancer(NSCLC)accounts for 80%of these cases,primarily comprising two subtypes:lung adenocarcinom...Dear Editor,Lung cancer is a major global health concern,with 2.2 million patients diagnosed in 2020.Non-small cell lung cancer(NSCLC)accounts for 80%of these cases,primarily comprising two subtypes:lung adenocarcinoma(LUAD)and squamous cell carcinoma(LUSC)[1].Researchers use immunohisto-chemistry,next-generation sequencing,and single-cell RNA sequencing to study genetic alterations,tumor heterogeneity,and tumor microenvironments,aiming to identify potential therapeutic options for specific NSCLC subtypes[2].展开更多
Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were ra...Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were randomized equally into control group and heat stress group.After exposure to 32℃for 2 weeks in the latter group,the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry.In the cell experiments,cultured rat thoracic aortic endothelial cells(RTAECs)were incubated at 40℃for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA(si-Bmal1)or a negative sequence.In both rat thoracic aorta and RTAECs,the expressions of Bmal1,the cell cycle proteins CDK1,CDK4,CDK6,and cyclin B1,and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting.TUNEL staining was used to detect cell apoptosis in rat thoracic aorta,and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry.Results Compared with the control rats,the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1,cyclin B1 and CDK1 in the thoracic aorta(P<0.05).In cultured RTAECs,heat stress caused significant increase of Bmal1,cyclin B1 and CDK1 protein expression levels,which were obviously lowered in cells with prior si-Bmal1 transfection.Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2.Conclusion Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells,which can be partly alleviated by suppressing Bmal1 expression.展开更多
基金Supported by Innovative Practice Platform for Undergraduate Students,School of Public Health Xiamen University,No.2021001.
文摘BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression results in a loss of this capacity to facilitate cyclin E degradation.The ubiquitination and degradation of cyclin E1 may be associated with phosphorylation at specific sites on the protein,with Cx43 potentially enhancing this process by facilitating the phosphorylation of these critical residues.AIM To investigate the correlation between expression of Cx43,SKP1/Cullin1/F-box(SCF)FBXW7,p-cyclin E1(ser73,thr77,thr395)and clinicopathological indexes in colon cancer.METHODS Expression levels of Cx43,SCF^(FBXW7),p-cyclin E1(ser73,thr77,thr395)in 38 clinical colon cancer samples were detected by immunohistochemistry and were analyzed by statistical methods to discuss their correlations.RESULTS Positive rate of Cx43,SCF^(FBXW7),p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in detected samples were 76.32%,76.32%,65.79%,5.26%and 55.26%respectively.Positive expressions of these proteins were not related to the tissue type,degree of tissue differentiation or lymph node metastasis.Cx43 and SCF^(FBXW7)(r=0.749),p-cyclin E1(Ser73)(r=0.667)and p-cyclin E1(Thr395)(r=0.457),SCF^(FBXW7) and p-cyclin E1(Ser73)(r=0.703)and p-cyclin E1(Thr395)(0.415)were correlated in colon cancer(P<0.05),and expressions of the above proteins were positively correlated in colon cancer.CONCLUSION Cx43 may facilitate the phosphorylation of cyclin E1 at the Ser73 and Thr195 sites through its interaction with SCF^(FBXW7),thereby influencing the ubiquitination and degradation of cyclin E1.
基金supported by the Zhejiang Provincial Nat ural Science Foundation of China(Nos.LZ23C060002 and LZ24H160004)the National Natural Science Foundation of China(Nos.32270746,82203247,82203415,82272637,82204429,and 82073332)+2 种基金the National Key Research and Development Program of China(No.2022YFE0107800)the Medical Interdisciplinary Innovation Program 2024,Zhejiang University School of Medicine,and the Fundamental Research Funds for the Central Universities(No.K20220228)It is add-itionally supported by the National Institute of Health(No.R01-CA200992-03).
文摘Cancer is characterized by abnormal cell proliferation.Cyclins and cyclin-dependent kinases(CDKs)have been recognized as essential regulators of the intricate cell cycle,orchestrating DNA replication and transcription,RNA splicing,and protein synthesis.Dysregulation of the CDK pathway is prevalent in the development and progression of human cancers,rendering cyclins and CDKs attractive therapeutic targets.Several CDK4/6 inhibitors have demonstrated promising anti-cancer efficacy and have been successfully translated into clinical use,fueling the development of CDK-targeted therapies.With this enthusiasm for finding novel CDK-targeting anti-cancer agents,there have also been exciting advances in the field of targeted protein degradation through innovative strategies,such as using proteolysis-targeting chimera,heat shock protein 90(HSP90)-mediated targeting chimera,hydrophobic tag-based protein degradation,and molecular glue.With a focus on the translational potential of cyclin-and CDK-targeting strategies in cancer,this review presents the fundamental roles of cyclins and CDKs in cancer.Furthermore,it summarizes current strategies for the proteasome-dependent targeted degradation of cyclins and CDKs,detailing the underlying mechanisms of action for each approach.A comprehensive overview of the structure and activity of existing CDK degraders is also provided.By examining the structure‒activity relationships,target profiles,and biological effects of reported cyclin/CDK degraders,this review provides a valuable reference for both CDK pathway-targeted biomedical research and cancer therapeutics.
基金support through Manipal University Jaipur for the Enhanced Seed Grant under the Endowment Fund(Grant No.E3/2023-24/QE-04-05).
文摘Dear Editor,Lung cancer is a major global health concern,with 2.2 million patients diagnosed in 2020.Non-small cell lung cancer(NSCLC)accounts for 80%of these cases,primarily comprising two subtypes:lung adenocarcinoma(LUAD)and squamous cell carcinoma(LUSC)[1].Researchers use immunohisto-chemistry,next-generation sequencing,and single-cell RNA sequencing to study genetic alterations,tumor heterogeneity,and tumor microenvironments,aiming to identify potential therapeutic options for specific NSCLC subtypes[2].
文摘Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were randomized equally into control group and heat stress group.After exposure to 32℃for 2 weeks in the latter group,the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry.In the cell experiments,cultured rat thoracic aortic endothelial cells(RTAECs)were incubated at 40℃for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA(si-Bmal1)or a negative sequence.In both rat thoracic aorta and RTAECs,the expressions of Bmal1,the cell cycle proteins CDK1,CDK4,CDK6,and cyclin B1,and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting.TUNEL staining was used to detect cell apoptosis in rat thoracic aorta,and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry.Results Compared with the control rats,the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1,cyclin B1 and CDK1 in the thoracic aorta(P<0.05).In cultured RTAECs,heat stress caused significant increase of Bmal1,cyclin B1 and CDK1 protein expression levels,which were obviously lowered in cells with prior si-Bmal1 transfection.Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2.Conclusion Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells,which can be partly alleviated by suppressing Bmal1 expression.
