BACKGROUND Pathological complete response(pCR) is rare in hormone receptor-positive(HR+)HER2-negative breast cancer(BC) treated with either endocrine therapy(ET) or chemotherapy. Radical resection of locoregional rela...BACKGROUND Pathological complete response(pCR) is rare in hormone receptor-positive(HR+)HER2-negative breast cancer(BC) treated with either endocrine therapy(ET) or chemotherapy. Radical resection of locoregional relapse, although potentially curative in some cases, is challenging when the tumor invades critical structures.The oral cyclin-dependent kinase 4/6 inhibitor palbociclib in combination with ET has obtained a significant increase in objective response rates and progression-free survival in patients with advanced BC and is now being evaluated in the neoadjuvant setting. We present a clinical case of a patient with an inoperable locoregional relapse of HR+ HER2-negative BC who experienced p CR after treatment with palbociclib.CASE SUMMARY We report the clinical case of a 60-year-old patient who presented with an inoperable locoregional relapse of HR+, HER2-negative BC 10 years after the diagnosis of the primary tumor. During a routine follow-up visit, breast magnetic resonance imaging and positron emission tomography/computed tomography revealed a 4-cm lesion in the right subclavicular region, infiltrating the chest wall and extending to the subclavian vessels, but without bone or visceral involvement. Treatment was begun with palbociclib plus letrozole, converting the disease to operability over a period of 6 mo. Surgery was performed and a p CR achieved. Of note, during treatment the patient experienced a very uncommon toxicity characterized by burning tongue and glossodynia associated with dysgeusia, paresthesia, dysesthesia, and xerostomia. A reduction in the dose of palbociclib did not provide relief and treatment with the inhibitor was thus discontinued, resolving the tongue symptoms. Laboratory exams were unremarkable. Given that this was a late relapse, the tumor was classified asendocrine-sensitive, a condition associated with high sensitivity to palbociclib.CONCLUSION This case highlights the potential of the cyclin-dependent kinase 4/6 inhibitor plus ET combination to achieve pCR in locoregional relapse of BC, enabling surgical resection of a lesion initially considered inoperable.展开更多
Background:The sensitivity of breast cancer cells to radiation is a key cause of locoregional recurrence after postoperative radiotherapy.Several studies have reported that microRNAs(miRNAs)are involved in the radiose...Background:The sensitivity of breast cancer cells to radiation is a key cause of locoregional recurrence after postoperative radiotherapy.Several studies have reported that microRNAs(miRNAs)are involved in the radiosensitivity of human breast cancer cells.One miRNA microarray study showed that miR-450b-5p was overexpressed 13.3-fold in patients with estrogen receptor–positive(ER^(+))and human epidermal growth factor receptor 2–negative(HER2−)breast cancer and no local relapse compared with local relapse patients.However,its underlying mechanism of action remains unknown.Methods:The predicted target mRNAs of miR-450b-5p were screened using the TargetScan,miRDB,and miRWalk databases.Western blotting,quantitative polymerase chain reaction,and dual-luciferase reporter assays explored the association between cyclindependent kinase 6(CDK6)and miR-450b-5p.The cell counting kit-8 assay and flow cytometry detected the proliferation of transfected MCF7 cells.Colony formation and xenograft tumors detected the radiosensitivity of the transfected MCF7 cells.Results:Bioinformatics analysis,Western blotting,quantitative polymerase chain reaction,and dual-luciferase reporter assays demonstrated that CDK6 was the target gene of miR-450b-5p.Furthermore,in vitro and in vivo experiments showed that miR-450b-5p inhibited MCF7 cell proliferation and cell cycle progression,increased the sensitizer enhancement ratio,and decreased the volume of xenograft tumors after irradiation by regulating CDK6.Conclusions:This study demonstrates that miR-450b-5p enhances the radiosensitivity of hormone receptor–positive(HR^(+))and HER2−breast cancer cells and elucidates its mechanism.miR-450b-5p may be considered a therapeutic target in HR^(+)and HER2−breast cancer treated with radiotherapy.展开更多
OBJECTIVE Previous studies have demonstrated acetylcholine muscarinic 4(M4) receptor regulates DARPP-32 phosphorylation at Thr75 in isolated medium spiny neurons(MSNs),indicating antagonistic mechanism with D1 depende...OBJECTIVE Previous studies have demonstrated acetylcholine muscarinic 4(M4) receptor regulates DARPP-32 phosphorylation at Thr75 in isolated medium spiny neurons(MSNs),indicating antagonistic mechanism with D1 dependent signal cascade,but the exact molecular mechanisms remain unclearly.In this study,we investigated the roles of M4 receptor in modulation D1 dependent signal to integrate striatal DA inputs in isolated MSNs.METHODS(1)Lentivirus technology was employed to genetically knock down the M4 receptor of MSNs;(2) Apomorphine(APO),acts as a dopamine receptor agonist,while SCH23390,acts as a selective antagonist for D1,were used to study the pharmacologically profiles with D1 receptor stimulation or blockade,respectively.Then the no subtype-selective muscarinic agonist oxotremorine M(OX) were used to show that mAchRs activation,in order to dissect the particular function of M4,a selective M4 antagonist,MT3 was used;(3) Intracellular cAMP production of MSNs was measured by using time resolved fluorescence resonance energy transfer detection method;(4) Laser confocal was used to explore the expression of M4 and D1 in MSNs;(5) Immunofluorescence cytochemistry and Western blotting were used to confirm the alteration of signaling molecular including P-CREB,DARPP-32 P-Thr34,DARPP-32 P-Thr75,cyclin-dependent kinase 5(CDK5) as wel as p25/35,which are involved in DA-dependent signaling modulations.RESULTS Firstly,TR-FRET assay revealed APO(10-2 mol·L^(-1))significantly increased the level of intracellular cAMP(vs control,n=3,P<0.01),also Western blotting results showed that APO(10-6 mol · L^(-1))increased DARPP-32 Thr34 phosphorylation(vs control,n=3,P<0.01),and these effect were reversed by D1 receptor antagonist SCH23390(vs APO,n=3,P<0.01).Interestingly,we confirmed that OX(10-6 mol · L^(-1)) down-regulated APO-induced DARPP-32 Thr34 phosphorylation(vs APO,n=3,P<0.01),due to its effects on DARPP-32 phosphorylation at Thr75.The results presented the antagonistic mechanism of mAchRs stimulation with D1 dependent signal cascade in MSNs.Meanwhile,OX(10-7,10-6 and10^(-5) mol·L^(-1)) stimulated DARPP-32 phosphorylation at Thr75,and simultaneously up regulated P25/35 and CDK5 activity(vs control,n=3,P<0.01) by using Western blotting assay.Furthermore,roscovitine(10^(-5) mol · L^(-1)),acts as a CDK5 inhibitor,suppressed CDK5 activity(vs control,n=10,P<0.01),and fully inhibited OX-induced DARPP-32 Thr75 phosphorylation(vs OX,n=10,P<0.01).More important,pretreated with roscovitine(10^(-5) mol·L^(-1)),the effect of APO on DARPP-32 Thr34 phosphorylation was potentiated(vs APO,n=3,P<0.05).The result presented CDK5 is required in suppression of APO on DARPP-32 Thr34 phosphorylation mediated through mAchRs stimulation.In addition,laser confocal results showed that the CDK5 up-regulation was mostly confined to MSNs co-expressing M4,which means that M4 participated in CDK5-mediated phosphorylation of DARPP-32 at Thr75.Consistently,immunofluorescence and Western blotting results confirmed that both genetic knockdown and pharmacologic inhibition of M4 receptors with MT3(10-7 mol · L^(-1)) down-regulated the OX-induced the expression of CDK5(vs OX,n=3,P<0.01) and P25/35(vs OX,n=3,P<0.01)in isolated MSNs.CONCLUSION M4 receptor may play an important role in antagonistic regulation D1 dependent signaling,in which CDK5 is required for suppressing D1-DARPP-32 Thr34 phosphorylation in isolated medium spiny neurons.展开更多
Abemaciclib (Verzerio<span style="white-space:nowrap;"><sup><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">®</span>...Abemaciclib (Verzerio<span style="white-space:nowrap;"><sup><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">®</span></sup></span>) is a cell cycle inhibitor of both CDK4 and CDK6. In 2017, abemaciclib was approved by the Food and Drug Administration (FDA) and, in 2018 by the European Medicines Agency (EMA) for the treatment of postmenopausal women with hormone receptor positive (HR<sup>+</sup>), human epidermal growth factor receptor 2 negative (HER2<sup><span style="white-space:nowrap;"><sup><span style="white-space:nowrap;">−</span></sup></span></sup>) advanced breast cancer. In this mini-review, we provide a series of information for respectively their targets and its selectivity, results on preclinical trial, clinical phase I, II and III trials, and some perspectives. We also describe the batch and flow steps used for the synthesis of this cancer drug.展开更多
文摘BACKGROUND Pathological complete response(pCR) is rare in hormone receptor-positive(HR+)HER2-negative breast cancer(BC) treated with either endocrine therapy(ET) or chemotherapy. Radical resection of locoregional relapse, although potentially curative in some cases, is challenging when the tumor invades critical structures.The oral cyclin-dependent kinase 4/6 inhibitor palbociclib in combination with ET has obtained a significant increase in objective response rates and progression-free survival in patients with advanced BC and is now being evaluated in the neoadjuvant setting. We present a clinical case of a patient with an inoperable locoregional relapse of HR+ HER2-negative BC who experienced p CR after treatment with palbociclib.CASE SUMMARY We report the clinical case of a 60-year-old patient who presented with an inoperable locoregional relapse of HR+, HER2-negative BC 10 years after the diagnosis of the primary tumor. During a routine follow-up visit, breast magnetic resonance imaging and positron emission tomography/computed tomography revealed a 4-cm lesion in the right subclavicular region, infiltrating the chest wall and extending to the subclavian vessels, but without bone or visceral involvement. Treatment was begun with palbociclib plus letrozole, converting the disease to operability over a period of 6 mo. Surgery was performed and a p CR achieved. Of note, during treatment the patient experienced a very uncommon toxicity characterized by burning tongue and glossodynia associated with dysgeusia, paresthesia, dysesthesia, and xerostomia. A reduction in the dose of palbociclib did not provide relief and treatment with the inhibitor was thus discontinued, resolving the tongue symptoms. Laboratory exams were unremarkable. Given that this was a late relapse, the tumor was classified asendocrine-sensitive, a condition associated with high sensitivity to palbociclib.CONCLUSION This case highlights the potential of the cyclin-dependent kinase 4/6 inhibitor plus ET combination to achieve pCR in locoregional relapse of BC, enabling surgical resection of a lesion initially considered inoperable.
文摘Background:The sensitivity of breast cancer cells to radiation is a key cause of locoregional recurrence after postoperative radiotherapy.Several studies have reported that microRNAs(miRNAs)are involved in the radiosensitivity of human breast cancer cells.One miRNA microarray study showed that miR-450b-5p was overexpressed 13.3-fold in patients with estrogen receptor–positive(ER^(+))and human epidermal growth factor receptor 2–negative(HER2−)breast cancer and no local relapse compared with local relapse patients.However,its underlying mechanism of action remains unknown.Methods:The predicted target mRNAs of miR-450b-5p were screened using the TargetScan,miRDB,and miRWalk databases.Western blotting,quantitative polymerase chain reaction,and dual-luciferase reporter assays explored the association between cyclindependent kinase 6(CDK6)and miR-450b-5p.The cell counting kit-8 assay and flow cytometry detected the proliferation of transfected MCF7 cells.Colony formation and xenograft tumors detected the radiosensitivity of the transfected MCF7 cells.Results:Bioinformatics analysis,Western blotting,quantitative polymerase chain reaction,and dual-luciferase reporter assays demonstrated that CDK6 was the target gene of miR-450b-5p.Furthermore,in vitro and in vivo experiments showed that miR-450b-5p inhibited MCF7 cell proliferation and cell cycle progression,increased the sensitizer enhancement ratio,and decreased the volume of xenograft tumors after irradiation by regulating CDK6.Conclusions:This study demonstrates that miR-450b-5p enhances the radiosensitivity of hormone receptor–positive(HR^(+))and HER2−breast cancer cells and elucidates its mechanism.miR-450b-5p may be considered a therapeutic target in HR^(+)and HER2−breast cancer treated with radiotherapy.
文摘OBJECTIVE Previous studies have demonstrated acetylcholine muscarinic 4(M4) receptor regulates DARPP-32 phosphorylation at Thr75 in isolated medium spiny neurons(MSNs),indicating antagonistic mechanism with D1 dependent signal cascade,but the exact molecular mechanisms remain unclearly.In this study,we investigated the roles of M4 receptor in modulation D1 dependent signal to integrate striatal DA inputs in isolated MSNs.METHODS(1)Lentivirus technology was employed to genetically knock down the M4 receptor of MSNs;(2) Apomorphine(APO),acts as a dopamine receptor agonist,while SCH23390,acts as a selective antagonist for D1,were used to study the pharmacologically profiles with D1 receptor stimulation or blockade,respectively.Then the no subtype-selective muscarinic agonist oxotremorine M(OX) were used to show that mAchRs activation,in order to dissect the particular function of M4,a selective M4 antagonist,MT3 was used;(3) Intracellular cAMP production of MSNs was measured by using time resolved fluorescence resonance energy transfer detection method;(4) Laser confocal was used to explore the expression of M4 and D1 in MSNs;(5) Immunofluorescence cytochemistry and Western blotting were used to confirm the alteration of signaling molecular including P-CREB,DARPP-32 P-Thr34,DARPP-32 P-Thr75,cyclin-dependent kinase 5(CDK5) as wel as p25/35,which are involved in DA-dependent signaling modulations.RESULTS Firstly,TR-FRET assay revealed APO(10-2 mol·L^(-1))significantly increased the level of intracellular cAMP(vs control,n=3,P<0.01),also Western blotting results showed that APO(10-6 mol · L^(-1))increased DARPP-32 Thr34 phosphorylation(vs control,n=3,P<0.01),and these effect were reversed by D1 receptor antagonist SCH23390(vs APO,n=3,P<0.01).Interestingly,we confirmed that OX(10-6 mol · L^(-1)) down-regulated APO-induced DARPP-32 Thr34 phosphorylation(vs APO,n=3,P<0.01),due to its effects on DARPP-32 phosphorylation at Thr75.The results presented the antagonistic mechanism of mAchRs stimulation with D1 dependent signal cascade in MSNs.Meanwhile,OX(10-7,10-6 and10^(-5) mol·L^(-1)) stimulated DARPP-32 phosphorylation at Thr75,and simultaneously up regulated P25/35 and CDK5 activity(vs control,n=3,P<0.01) by using Western blotting assay.Furthermore,roscovitine(10^(-5) mol · L^(-1)),acts as a CDK5 inhibitor,suppressed CDK5 activity(vs control,n=10,P<0.01),and fully inhibited OX-induced DARPP-32 Thr75 phosphorylation(vs OX,n=10,P<0.01).More important,pretreated with roscovitine(10^(-5) mol·L^(-1)),the effect of APO on DARPP-32 Thr34 phosphorylation was potentiated(vs APO,n=3,P<0.05).The result presented CDK5 is required in suppression of APO on DARPP-32 Thr34 phosphorylation mediated through mAchRs stimulation.In addition,laser confocal results showed that the CDK5 up-regulation was mostly confined to MSNs co-expressing M4,which means that M4 participated in CDK5-mediated phosphorylation of DARPP-32 at Thr75.Consistently,immunofluorescence and Western blotting results confirmed that both genetic knockdown and pharmacologic inhibition of M4 receptors with MT3(10-7 mol · L^(-1)) down-regulated the OX-induced the expression of CDK5(vs OX,n=3,P<0.01) and P25/35(vs OX,n=3,P<0.01)in isolated MSNs.CONCLUSION M4 receptor may play an important role in antagonistic regulation D1 dependent signaling,in which CDK5 is required for suppressing D1-DARPP-32 Thr34 phosphorylation in isolated medium spiny neurons.
文摘Abemaciclib (Verzerio<span style="white-space:nowrap;"><sup><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">®</span></sup></span>) is a cell cycle inhibitor of both CDK4 and CDK6. In 2017, abemaciclib was approved by the Food and Drug Administration (FDA) and, in 2018 by the European Medicines Agency (EMA) for the treatment of postmenopausal women with hormone receptor positive (HR<sup>+</sup>), human epidermal growth factor receptor 2 negative (HER2<sup><span style="white-space:nowrap;"><sup><span style="white-space:nowrap;">−</span></sup></span></sup>) advanced breast cancer. In this mini-review, we provide a series of information for respectively their targets and its selectivity, results on preclinical trial, clinical phase I, II and III trials, and some perspectives. We also describe the batch and flow steps used for the synthesis of this cancer drug.
