Objectives:This study aimed to determine the role and mechanism underlying migration and invasion inhibitory protein(MIIP)modulation in M2 macrophages within the tumor microenvironment and the potential of targeting t...Objectives:This study aimed to determine the role and mechanism underlying migration and invasion inhibitory protein(MIIP)modulation in M2 macrophages within the tumor microenvironment and the potential of targeting the MIIP-stimulator of interferon genes(STING)pathway in colorectal cancer(CRC)therapy.Methods:MIIP expression was analyzed for associations with the STING pathway and M2 macrophage infiltration using public datasets and clinical CRC samples.CRC cells were genetically modified using lentiviral vectors to overexpress or silence MIIP and STING.The interactions of genetically modified CRC cells with macrophages were studied in co-culture systems.Techniques,including immunofluorescence staining,RT‒qPCR,western blot,ELISA,flow cytometry,and Transwell migration and invasion assays,were used to evaluate the crosstalk between CRC cells and macrophages.An orthotopic mouse CRC model was developed to study the effects of MIIP on M2 macrophage polarization and tumor metastasis through the STING-NFκB2-IL10 axis.The therapeutic significance of a STING antagonist was also assessed in vivo.Results:Analyses of The Cancer Genome Atlas(TCGA)cohort and our CRC cohort revealed low MIIP expression is associated with STING pathway activation,increased M2 macrophage infiltration,and poor clinical outcomes.The results of functional experiments demonstrated that MIIP inhibits IL10 production via the STING-TRAF3-NFκB2 axis in CRC cells,suppressing M2 macrophage polarization in co-culture systems.Conversely,M2 macrophages promoted CRC cell migration and invasion in an IL10-dependent manner.In vitro and in vivo studies confirmed that the MIIP-mediated feedback loop between CRC cells and macrophages depends on the STING-NFκB2-IL10 axis.Furthermore,inhibition of STING expression in a mouse model reduced M2 macrophage polarization and tumor metastasis.Conclusions:This study established MIIP as a crucial regulator of macrophage polarization in the CRC tumor microenvironment,providing new insights into the role in suppressing CRC progression and immune-tumor crosstalk.These findings highlight the potential of targeting the STING pathway as a therapeutic strategy for CRC patients who respond poorly to immune checkpoint inhibitors.展开更多
Background:Hepatocellular carcinoma(HCC)is an aggressive and lethal malignancy.Metabolic reprogramming dynamically remodels the tumor microenvironment(TME)and drives HCC progression.This study investigated the mechani...Background:Hepatocellular carcinoma(HCC)is an aggressive and lethal malignancy.Metabolic reprogramming dynamically remodels the tumor microenvironment(TME)and drives HCC progression.This study investigated the mechanism through which metabolic reprogramming remodels the TME in HCC.Methods:HCC patient transcriptome data were subjected to bioinformatics analysis to identify differentially expressed genes and immune infiltration status.Immunohistochemical analysis was performed to determine the correlation between succinate dehydrogenase complex subunit A(SDHA)expression and M2 macrophage infiltration.SDHA-knockdown or SDHA-overexpressing HCC cells were used for in vitro experiments,including co-culturing,flow cytometry,and enzyme-linked immunosorbent assay.Western blotting assay,functional assays,and subcutaneous tumor model mice were used to elucidate the molecular mechanisms underlying succinate-mediated HCC cell-macrophage interactions in the TME.Results:Higher infiltration of M2 macrophages correlated with worse prognosis in HCC patients.SDHA was downregulated in HCC tumor tissues and showed a negative correlation with M2 macrophage infiltration.SDHA knockdown promoted M2 macrophage polarization,whereas SDHA overexpression reversed this effect.Mechanistically,SDHA deficiency in HCC cells induced succinate accumulation,which promoted M2 macrophage polarization by activating the G protein-coupled receptor 91(GPR91)/signal transducer and activator of transcription 3(STAT3)pathway.Concurrently,succinate stimulation enhanced mitochondrial oxidative phosphorylation in M2 macrophages,thereby promoting HCC progression.Serum succinate levels were elevated in HCC patients.The receiver operating characteristic curve analysis indicated that serum succinate is a promising diagnostic marker for HCC(area under the curve=0.815).Conclusion:SDHA deficiency leads to succinate accumulation,which promotes M2 macrophage polarization through the GPR91/STAT3 pathway,thereby facilitating HCC progression.Based on these findings,serum succinate could be a promising diagnostic biomarker for HCC.展开更多
文摘Objectives:This study aimed to determine the role and mechanism underlying migration and invasion inhibitory protein(MIIP)modulation in M2 macrophages within the tumor microenvironment and the potential of targeting the MIIP-stimulator of interferon genes(STING)pathway in colorectal cancer(CRC)therapy.Methods:MIIP expression was analyzed for associations with the STING pathway and M2 macrophage infiltration using public datasets and clinical CRC samples.CRC cells were genetically modified using lentiviral vectors to overexpress or silence MIIP and STING.The interactions of genetically modified CRC cells with macrophages were studied in co-culture systems.Techniques,including immunofluorescence staining,RT‒qPCR,western blot,ELISA,flow cytometry,and Transwell migration and invasion assays,were used to evaluate the crosstalk between CRC cells and macrophages.An orthotopic mouse CRC model was developed to study the effects of MIIP on M2 macrophage polarization and tumor metastasis through the STING-NFκB2-IL10 axis.The therapeutic significance of a STING antagonist was also assessed in vivo.Results:Analyses of The Cancer Genome Atlas(TCGA)cohort and our CRC cohort revealed low MIIP expression is associated with STING pathway activation,increased M2 macrophage infiltration,and poor clinical outcomes.The results of functional experiments demonstrated that MIIP inhibits IL10 production via the STING-TRAF3-NFκB2 axis in CRC cells,suppressing M2 macrophage polarization in co-culture systems.Conversely,M2 macrophages promoted CRC cell migration and invasion in an IL10-dependent manner.In vitro and in vivo studies confirmed that the MIIP-mediated feedback loop between CRC cells and macrophages depends on the STING-NFκB2-IL10 axis.Furthermore,inhibition of STING expression in a mouse model reduced M2 macrophage polarization and tumor metastasis.Conclusions:This study established MIIP as a crucial regulator of macrophage polarization in the CRC tumor microenvironment,providing new insights into the role in suppressing CRC progression and immune-tumor crosstalk.These findings highlight the potential of targeting the STING pathway as a therapeutic strategy for CRC patients who respond poorly to immune checkpoint inhibitors.
基金supported by the Central Government-Guided Local Science and Technology Development Fund Project(Science and Technology Innovation Base Project)(Grant No.236Z7749G)Hebei Provincial Precision Medicine Innovation and Development Joint Fund Incubation Project(Grant No.H2025206547)Hebei Provincial Basic Research Special Youth Science Fund Project(Grant No.H2025206274).
文摘Background:Hepatocellular carcinoma(HCC)is an aggressive and lethal malignancy.Metabolic reprogramming dynamically remodels the tumor microenvironment(TME)and drives HCC progression.This study investigated the mechanism through which metabolic reprogramming remodels the TME in HCC.Methods:HCC patient transcriptome data were subjected to bioinformatics analysis to identify differentially expressed genes and immune infiltration status.Immunohistochemical analysis was performed to determine the correlation between succinate dehydrogenase complex subunit A(SDHA)expression and M2 macrophage infiltration.SDHA-knockdown or SDHA-overexpressing HCC cells were used for in vitro experiments,including co-culturing,flow cytometry,and enzyme-linked immunosorbent assay.Western blotting assay,functional assays,and subcutaneous tumor model mice were used to elucidate the molecular mechanisms underlying succinate-mediated HCC cell-macrophage interactions in the TME.Results:Higher infiltration of M2 macrophages correlated with worse prognosis in HCC patients.SDHA was downregulated in HCC tumor tissues and showed a negative correlation with M2 macrophage infiltration.SDHA knockdown promoted M2 macrophage polarization,whereas SDHA overexpression reversed this effect.Mechanistically,SDHA deficiency in HCC cells induced succinate accumulation,which promoted M2 macrophage polarization by activating the G protein-coupled receptor 91(GPR91)/signal transducer and activator of transcription 3(STAT3)pathway.Concurrently,succinate stimulation enhanced mitochondrial oxidative phosphorylation in M2 macrophages,thereby promoting HCC progression.Serum succinate levels were elevated in HCC patients.The receiver operating characteristic curve analysis indicated that serum succinate is a promising diagnostic marker for HCC(area under the curve=0.815).Conclusion:SDHA deficiency leads to succinate accumulation,which promotes M2 macrophage polarization through the GPR91/STAT3 pathway,thereby facilitating HCC progression.Based on these findings,serum succinate could be a promising diagnostic biomarker for HCC.
