AIM： TO investigate in vivo, whether CCK2 receptors （CCK2R） regulate proteins known to play a crucial role in cell proliferation and cancer development and analyse in vitro the molecular mechanisms that lead to Src...AIM： TO investigate in vivo, whether CCK2 receptors （CCK2R） regulate proteins known to play a crucial role in cell proliferation and cancer development and analyse in vitro the molecular mechanisms that lead to Src activation; in particular, to identify the domains within the CCK2R sequence that are implicated in this activation. METHODS： The expression and activation of Src and ERK were studied in vivo using immunofluorescence and western-blot techniques. We used pancreatic tissues derived from wild type or Elas-CCK2 mice that expressed the CCK2R in pancreatic acini, displayed an increased pancreatic growth and developed preneoplastic lesions. The pancreatic tumor cell line AR4-2J expressing the endogenous CCK2R or COS-7 cells transiently transfected with wild type or mutant CCK2R were used as in vitro models to study the mechanism of Src activation. Src activation was measured by in vitro kinase assays, ERK activation by western blot using antiphospho-ERK antibodies and the involvement of Src in gastrin-induced cell proliferation by MTT test. RESULTS： We showed in vivo that the targeted CCK2R expression in the pancreas of Elas-CCK2 mice, led to the activation of Src and the ERK pathway. Src was activated upstream of the ERK pathway by the CCK2R in pancreatic tumoral cells and contributed to the proliferative effects mediated by this receptor. In vitro results demonstrated that activation of the Src/ERK pathway by the CCK2R required the NPXXY motif, located within the CCK2R sequence at the end of the 7^th transmembrane domain, and suggested the putative role of Gq in this mechanism. CONCLUSION： Deregulation of the Src/ERK pathway by the CCK2R might represent an early step that contributes to cell proliferation, formation of preneoplastic lesions and pancreatic tumor development.展开更多
Radiopharmaceuticals are reshaping the landscape of cancer therapy,offering a unique theranostic advantage that is becoming increasingly central to precision medicine.By labeling the same molecular scaffold with diffe...Radiopharmaceuticals are reshaping the landscape of cancer therapy,offering a unique theranostic advantage that is becoming increasingly central to precision medicine.By labeling the same molecular scaffold with different radionuclides,these agents enable seamless integration of diagnostic imaging and targeted therapy.Clinical breakthroughs with somatostatin receptor subtype 2(SSTR2)-and prostate-specificmembrane antigen(PSMA)-targeted radiopharmaceuticals have significantly enhanced both tumor visualization and therapeutic efficacy,establishing new benchmarks in oncology.Ongoing research is exploring novel molecular targets such as cholecystokinin-2 receptor(CCK2R),fibroblast activation protein(FAP),and C-X-C chemokine receptor type 4(CXCR4).In parallel,there is growing interest in utilizing alternative radionuclides,including alpha-particle emitters and Auger electron emitters,beyond the commonly used beta-emitters,to improve therapeutic outcomes.Simultaneously,advances in ligand and linker design are being leveraged to optimize in vivo pharmacokinetics and tissue distribution.Among the emerging targets,CCK2R has attracted notable attention due to its overexpression in multiple malignancies.Research efforts have focused on improving ligand stability,receptor-binding affinity,and tumor retention,while also exploring strategies to enhance CCK2R expression on cancer cells.This review offers a comprehensive overview of the current landscape in cancer radiotheranostics,exploring the role of CCK2R in cancer biology and summarizing the latest advancements in the development of CCK2R-targeted radiopharmaceuticals.Using these advancements as a case study,we systematically examine key aspects of next-generation radiopharmaceutical design,from target selection and ligand engineering to pharmacokinetic optimization and clinical translation,providing a multidimensional framework for future innovation in cancer radiotheranostics.展开更多
基金Supported by funds from INSERM, the "Association pour la Recherche contre le Cancer" Grants, No. 3664, the "Region Midi Pyréeés". Audrey Ferrand was supported by the Ligue Nationale contre le cancer
文摘AIM： TO investigate in vivo, whether CCK2 receptors （CCK2R） regulate proteins known to play a crucial role in cell proliferation and cancer development and analyse in vitro the molecular mechanisms that lead to Src activation; in particular, to identify the domains within the CCK2R sequence that are implicated in this activation. METHODS： The expression and activation of Src and ERK were studied in vivo using immunofluorescence and western-blot techniques. We used pancreatic tissues derived from wild type or Elas-CCK2 mice that expressed the CCK2R in pancreatic acini, displayed an increased pancreatic growth and developed preneoplastic lesions. The pancreatic tumor cell line AR4-2J expressing the endogenous CCK2R or COS-7 cells transiently transfected with wild type or mutant CCK2R were used as in vitro models to study the mechanism of Src activation. Src activation was measured by in vitro kinase assays, ERK activation by western blot using antiphospho-ERK antibodies and the involvement of Src in gastrin-induced cell proliferation by MTT test. RESULTS： We showed in vivo that the targeted CCK2R expression in the pancreas of Elas-CCK2 mice, led to the activation of Src and the ERK pathway. Src was activated upstream of the ERK pathway by the CCK2R in pancreatic tumoral cells and contributed to the proliferative effects mediated by this receptor. In vitro results demonstrated that activation of the Src/ERK pathway by the CCK2R required the NPXXY motif, located within the CCK2R sequence at the end of the 7^th transmembrane domain, and suggested the putative role of Gq in this mechanism. CONCLUSION： Deregulation of the Src/ERK pathway by the CCK2R might represent an early step that contributes to cell proliferation, formation of preneoplastic lesions and pancreatic tumor development.
基金National University of Singapore,Grant/Award Numbers:NUHSRO/2021/097/Startup/13,NUHSRO/2020/133/Startup/08,NUHSRO/2023/008/NUS Med/TCE/LOANational Medical Research Council,Grant/Award Numbers:MOH-001483-00,MOH-001334-00,MOH-001388-00,MOH-001254-01,CG21APR1005+1 种基金Singapore Ministry of Education,Grant/Award Number:(FY2022)-Tier1-NUHSRO/2022/093/T1/Seed-Sep/06NUS School of Medicine Nanomedicine Translational Research Programme,Grant/Award Number:NUHSRO/2021/034/TRP/09/Nanomedicine。
文摘Radiopharmaceuticals are reshaping the landscape of cancer therapy,offering a unique theranostic advantage that is becoming increasingly central to precision medicine.By labeling the same molecular scaffold with different radionuclides,these agents enable seamless integration of diagnostic imaging and targeted therapy.Clinical breakthroughs with somatostatin receptor subtype 2(SSTR2)-and prostate-specificmembrane antigen(PSMA)-targeted radiopharmaceuticals have significantly enhanced both tumor visualization and therapeutic efficacy,establishing new benchmarks in oncology.Ongoing research is exploring novel molecular targets such as cholecystokinin-2 receptor(CCK2R),fibroblast activation protein(FAP),and C-X-C chemokine receptor type 4(CXCR4).In parallel,there is growing interest in utilizing alternative radionuclides,including alpha-particle emitters and Auger electron emitters,beyond the commonly used beta-emitters,to improve therapeutic outcomes.Simultaneously,advances in ligand and linker design are being leveraged to optimize in vivo pharmacokinetics and tissue distribution.Among the emerging targets,CCK2R has attracted notable attention due to its overexpression in multiple malignancies.Research efforts have focused on improving ligand stability,receptor-binding affinity,and tumor retention,while also exploring strategies to enhance CCK2R expression on cancer cells.This review offers a comprehensive overview of the current landscape in cancer radiotheranostics,exploring the role of CCK2R in cancer biology and summarizing the latest advancements in the development of CCK2R-targeted radiopharmaceuticals.Using these advancements as a case study,we systematically examine key aspects of next-generation radiopharmaceutical design,from target selection and ligand engineering to pharmacokinetic optimization and clinical translation,providing a multidimensional framework for future innovation in cancer radiotheranostics.
