Objective:MicroRNAs(miRNAs)are small,non-coding RNAs that play a key role in the development of chemoresistance in various cancer types,including colorectal cancer(CRC).In this study,we aimed to study the underlying m...Objective:MicroRNAs(miRNAs)are small,non-coding RNAs that play a key role in the development of chemoresistance in various cancer types,including colorectal cancer(CRC).In this study,we aimed to study the underlying mechanisms of miRNA in chemotherapy-resistant CRC.Methods:LoVo CRC cell line was exposed to oxaliplatin at an increased dose,and cells were cultured in the presence of oxaliplatin to develop LoVo^(OXR) cells.Microarray and Quantitative Reverse Transcription Polymerase Chain Reaction(qRT-PCR),western blot,and transwell assay were used to evaluate the chemoresistance in LoVo^(OXR) CRC cells.Results:Microarray and qRT-PCR analysis showed an increased expression of miR-100-5p in LoVo^(OXR) cells.MTT assay and flow cytometry analysis revealed less apoptosis and higher cell viability in LoVo^(OXR) cells.mRNA prediction target gene analysis showed C-terminal domain small phosphatase-like(CTDSPL),a phosphatase-like tumor suppressor,as a key target of miR-100-5p.CTDSPL expression was low in LoVo^(OXR) cells compared to LoVoWT cells.miR-100-5p regulates G1/S and S-phase transitions and inhibits differentiation by targeting the CTDSPL/pRB/E2F1 signaling pathway,which involves the modulation of cell cycle effectors in LoVo^(OXR) cells.Further,we found that forkhead box P3(FOXP3),as the upstream target of miR-100-5p,is highly expressed in LoVo^(OXR) cells.Inhibiting miR-100-5p and FOXP3 down-regulates miR-100-5p expression,while increased CTDSPL expression contributed to reduced cell proliferation and promoted cell apoptosis in LoVo^(OXR) CRC cells.Conclusions:miR-100-5p plays an oncogenic role in inducing chemoresistance through modulation of the CTDSPL/retinoblastoma protein(pRB)/E2F transcription factor 1(E2F1)axis in CRC cells.展开更多
BACKGROUND Colorectal cancer(CRC)is a leading cause of cancer-related mortality worldwide,primarily due to tumor heterogeneity and treatment resistance.The leucine-rich repeat-containing protein 19(LRRC19)has been lin...BACKGROUND Colorectal cancer(CRC)is a leading cause of cancer-related mortality worldwide,primarily due to tumor heterogeneity and treatment resistance.The leucine-rich repeat-containing protein 19(LRRC19)has been linked to immune regulation and tumor suppression,yet its specific role in CRC remains poorly understood.AIM To investigate the tumor-suppressive role of LRRC19 in CRC,focusing on cell cycle,immune microenvironment,and chemotherapy response.METHODS Bioinformatics analyses of Gene Expression Omnibus and The Cancer Genome Atlas databases identified differentially expressed genes in CRC.LRRC19 exp-ression was validated in CRC tissues and cell lines by quantitative PCR,immuno-histochemistry,and Western blotting.Functional assays,including proliferation,soft agar colony formation,flow cytometry,and xenograft models,assessed biological effects.Mechanistic studies with dual-luciferase reporter assays,molecular docking,and drug sensitivity testing explored LRRC19’s interaction with the cyclin-dependent kinase 6(CDK6)/E2F1 axis and oxaliplatin(OXA)response.Single-cell sequencing and immune infiltration analyses assessed its impact on the immune microenvironment.RESULTS LRRC19 expression was significantly downregulated in CRC and associated with poor prognosis.Overexpression of LRRC19 inhibited CRC cell proliferation,induced G0/G1 phase arrest,and suppressed tumor growth in vivo.Mechanistically,LRRC19 suppressed CDK6 transcription by downregulating E2F1,leading to cell cycle arrest.Additionally,LRRC19 promoted immune cell infiltration,particularly B cells and CD4+T cells,while decreasing immunosuppressive cells.LRRC19 also sensitized CRC cells to OXA,enhancing chemotherapy efficacy.CONCLUSION LRRC19 suppresses CRC by targeting the CDK6/E2F1 axis,modulating the immune microenvironment,and enhancing chemotherapy sensitivity,making it a promising therapeutic target for precision medicine in CRC.展开更多
基金supported by the China Medical University Hospital,Department of Medical Research(DMR-110-209)the Ministry of Science and Technology,Taiwan(MOST:109-2320-B-303-001-MY2),CMU107-ASIA-08,CMU109-MF-76 and CMU105-ASIA-01Taichung Armed Forces General Hospital:TCAFGH_D_115034.
文摘Objective:MicroRNAs(miRNAs)are small,non-coding RNAs that play a key role in the development of chemoresistance in various cancer types,including colorectal cancer(CRC).In this study,we aimed to study the underlying mechanisms of miRNA in chemotherapy-resistant CRC.Methods:LoVo CRC cell line was exposed to oxaliplatin at an increased dose,and cells were cultured in the presence of oxaliplatin to develop LoVo^(OXR) cells.Microarray and Quantitative Reverse Transcription Polymerase Chain Reaction(qRT-PCR),western blot,and transwell assay were used to evaluate the chemoresistance in LoVo^(OXR) CRC cells.Results:Microarray and qRT-PCR analysis showed an increased expression of miR-100-5p in LoVo^(OXR) cells.MTT assay and flow cytometry analysis revealed less apoptosis and higher cell viability in LoVo^(OXR) cells.mRNA prediction target gene analysis showed C-terminal domain small phosphatase-like(CTDSPL),a phosphatase-like tumor suppressor,as a key target of miR-100-5p.CTDSPL expression was low in LoVo^(OXR) cells compared to LoVoWT cells.miR-100-5p regulates G1/S and S-phase transitions and inhibits differentiation by targeting the CTDSPL/pRB/E2F1 signaling pathway,which involves the modulation of cell cycle effectors in LoVo^(OXR) cells.Further,we found that forkhead box P3(FOXP3),as the upstream target of miR-100-5p,is highly expressed in LoVo^(OXR) cells.Inhibiting miR-100-5p and FOXP3 down-regulates miR-100-5p expression,while increased CTDSPL expression contributed to reduced cell proliferation and promoted cell apoptosis in LoVo^(OXR) CRC cells.Conclusions:miR-100-5p plays an oncogenic role in inducing chemoresistance through modulation of the CTDSPL/retinoblastoma protein(pRB)/E2F transcription factor 1(E2F1)axis in CRC cells.
基金Supported by the Natural Science Foundation of Zhejiang Province,No.LY22H160005。
文摘BACKGROUND Colorectal cancer(CRC)is a leading cause of cancer-related mortality worldwide,primarily due to tumor heterogeneity and treatment resistance.The leucine-rich repeat-containing protein 19(LRRC19)has been linked to immune regulation and tumor suppression,yet its specific role in CRC remains poorly understood.AIM To investigate the tumor-suppressive role of LRRC19 in CRC,focusing on cell cycle,immune microenvironment,and chemotherapy response.METHODS Bioinformatics analyses of Gene Expression Omnibus and The Cancer Genome Atlas databases identified differentially expressed genes in CRC.LRRC19 exp-ression was validated in CRC tissues and cell lines by quantitative PCR,immuno-histochemistry,and Western blotting.Functional assays,including proliferation,soft agar colony formation,flow cytometry,and xenograft models,assessed biological effects.Mechanistic studies with dual-luciferase reporter assays,molecular docking,and drug sensitivity testing explored LRRC19’s interaction with the cyclin-dependent kinase 6(CDK6)/E2F1 axis and oxaliplatin(OXA)response.Single-cell sequencing and immune infiltration analyses assessed its impact on the immune microenvironment.RESULTS LRRC19 expression was significantly downregulated in CRC and associated with poor prognosis.Overexpression of LRRC19 inhibited CRC cell proliferation,induced G0/G1 phase arrest,and suppressed tumor growth in vivo.Mechanistically,LRRC19 suppressed CDK6 transcription by downregulating E2F1,leading to cell cycle arrest.Additionally,LRRC19 promoted immune cell infiltration,particularly B cells and CD4+T cells,while decreasing immunosuppressive cells.LRRC19 also sensitized CRC cells to OXA,enhancing chemotherapy efficacy.CONCLUSION LRRC19 suppresses CRC by targeting the CDK6/E2F1 axis,modulating the immune microenvironment,and enhancing chemotherapy sensitivity,making it a promising therapeutic target for precision medicine in CRC.
