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
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.
