BACKGROUND Colorectal cancer(CRC)imposes a tremendous burden on human health,with high morbidity and mortality.Circular ribonucleic acids(circRNAs),a new type of noncoding RNA,are considered to participate in cancer p...BACKGROUND Colorectal cancer(CRC)imposes a tremendous burden on human health,with high morbidity and mortality.Circular ribonucleic acids(circRNAs),a new type of noncoding RNA,are considered to participate in cancer pathogenesis as microRNA(miRNA)sponges.However,the dysregulation and biological functions of circRNAs in CRC remain to be explored.AIM To identify potential circRNA biomarkers of CRC and explore their functions in CRC carcinogenesis.METHODS CircRNAs and miRNAs differentially expressed in CRC tissues were identified by analyzing expression profiles from the Gene Expression Omnibus(GEO)database.Circ_0000375 and circ_0011536 were selected as CRC biomarker candidates.Quantitative real-time polymerase chain reaction was utilized to evaluate the expression of these 2 circRNAs in CRC tissues,serums and cell lines.Receiver operating characteristic curves were generated to assess the diagnostic performances of these 2 circRNAs.Then,functional experiments,including cell counting kit-8,wound healing and Transwell invasion assays,were performed after the overexpression of circ_0000375 and circ_0011536 in CRC cell lines.Furthermore,candidate target miRNAs of circ_0000375 and circ_0011536 were predicted via bioinformatics analysis.The expression levels of these miRNAs were explored in CRC cell lines and tissues from GEO datasets.A luciferase reporter assay was developed to examine the interactions between circRNAs and miRNAs.Based on the target miRNAs and downstream genes,functional enrichment analyses were applied to reveal the critical signaling pathways involved in CRC carcinogenesis.RESULTS Downregulated circ_0000375 and circ_0011536 expression was observed in CRC tissues in GSE126095,clinical CRC tissue and serum samples and CRC cell lines.The areas under the curve for circ_0000375 and circ_0011536 were 0.911 and 0.885 in CRC tissue and 0.976 and 0.982 in CRC serum,respectively.Moreover,the serum levels of these 2 circRNAs were higher in patients at 30 d postsurgery than in patients before surgery,suggesting that the serum expression of circ_0000375 and circ_0011536 is related to CRC tumorigenesis.Circ_0000375 and circ_0011536 overexpression inhibited the proliferation,migration and invasion of CRC cells.Furthermore,miR-1182 and miR-1246,which were overexpressed in CRC tissues in GSE41655,GSE49246 and GSE115513,were verified as target miRNAs of circ_0000375 and circ_0011536,respectively,by luciferase reporter assays.The downstream genes of miR-1182 and miR-1246 were enriched in some CRC-associated pathways,such as the Wnt signaling pathway.CONCLUSION Circ_0000375 and circ_0011536 may function as tumor suppressors in CRC progression,serving as novel biomarkers for CRC diagnosis and as promising candidates for therapeutic exploration.展开更多
To confirm the relationship between Circ_0003855 and EC,we purchased the Human esophageal carcinoma cell line Eca109 and normal human esophageal epithelial cells HEEC,and the expression levels of Circ_0003855,miR-622,...To confirm the relationship between Circ_0003855 and EC,we purchased the Human esophageal carcinoma cell line Eca109 and normal human esophageal epithelial cells HEEC,and the expression levels of Circ_0003855,miR-622,and FLOT1 were detected.The results show that Circ_0003855 and FLOT1 were highly expressed in Eca109 cells,while miR-622 was lowly expressed(p<0.05).Subsequently,Circ_0003855 small interfering RNA(si-Circ_0003855)and its negative control(si-NC)were used to detect changes in cellular biological behaviors.We found that the activity of Eca109 cells was reduced after interfering with the expression of Circ_0003855,and miR-622 expression was elevated,while FLOT1 was decreased(p<0.05).Additionally,si-Circ_0003855 and miR-622 inhibitor sequence(miR-622-inhibition)were co-transfected into cells with miR-622-inhibition alone,and untreated Eca109 cells were used as a control to detect the expression of FLOT1.Co-transfection of si-Circ_0003855 and miR-622-inhibition showed no significant difference in FLOT1 expression compared to the control cells(p>0.05).Synthesizing the results of these experiments above,we believe that interfering with the expression of Circ_0003855 can inhibit the activity of EC cells,and its mechanism is related to miR-622 and FLOT1.展开更多
基金Supported by the National Key Development Plan for Precision Medicine Research,No. 2017YFC0910002
文摘BACKGROUND Colorectal cancer(CRC)imposes a tremendous burden on human health,with high morbidity and mortality.Circular ribonucleic acids(circRNAs),a new type of noncoding RNA,are considered to participate in cancer pathogenesis as microRNA(miRNA)sponges.However,the dysregulation and biological functions of circRNAs in CRC remain to be explored.AIM To identify potential circRNA biomarkers of CRC and explore their functions in CRC carcinogenesis.METHODS CircRNAs and miRNAs differentially expressed in CRC tissues were identified by analyzing expression profiles from the Gene Expression Omnibus(GEO)database.Circ_0000375 and circ_0011536 were selected as CRC biomarker candidates.Quantitative real-time polymerase chain reaction was utilized to evaluate the expression of these 2 circRNAs in CRC tissues,serums and cell lines.Receiver operating characteristic curves were generated to assess the diagnostic performances of these 2 circRNAs.Then,functional experiments,including cell counting kit-8,wound healing and Transwell invasion assays,were performed after the overexpression of circ_0000375 and circ_0011536 in CRC cell lines.Furthermore,candidate target miRNAs of circ_0000375 and circ_0011536 were predicted via bioinformatics analysis.The expression levels of these miRNAs were explored in CRC cell lines and tissues from GEO datasets.A luciferase reporter assay was developed to examine the interactions between circRNAs and miRNAs.Based on the target miRNAs and downstream genes,functional enrichment analyses were applied to reveal the critical signaling pathways involved in CRC carcinogenesis.RESULTS Downregulated circ_0000375 and circ_0011536 expression was observed in CRC tissues in GSE126095,clinical CRC tissue and serum samples and CRC cell lines.The areas under the curve for circ_0000375 and circ_0011536 were 0.911 and 0.885 in CRC tissue and 0.976 and 0.982 in CRC serum,respectively.Moreover,the serum levels of these 2 circRNAs were higher in patients at 30 d postsurgery than in patients before surgery,suggesting that the serum expression of circ_0000375 and circ_0011536 is related to CRC tumorigenesis.Circ_0000375 and circ_0011536 overexpression inhibited the proliferation,migration and invasion of CRC cells.Furthermore,miR-1182 and miR-1246,which were overexpressed in CRC tissues in GSE41655,GSE49246 and GSE115513,were verified as target miRNAs of circ_0000375 and circ_0011536,respectively,by luciferase reporter assays.The downstream genes of miR-1182 and miR-1246 were enriched in some CRC-associated pathways,such as the Wnt signaling pathway.CONCLUSION Circ_0000375 and circ_0011536 may function as tumor suppressors in CRC progression,serving as novel biomarkers for CRC diagnosis and as promising candidates for therapeutic exploration.
文摘To confirm the relationship between Circ_0003855 and EC,we purchased the Human esophageal carcinoma cell line Eca109 and normal human esophageal epithelial cells HEEC,and the expression levels of Circ_0003855,miR-622,and FLOT1 were detected.The results show that Circ_0003855 and FLOT1 were highly expressed in Eca109 cells,while miR-622 was lowly expressed(p<0.05).Subsequently,Circ_0003855 small interfering RNA(si-Circ_0003855)and its negative control(si-NC)were used to detect changes in cellular biological behaviors.We found that the activity of Eca109 cells was reduced after interfering with the expression of Circ_0003855,and miR-622 expression was elevated,while FLOT1 was decreased(p<0.05).Additionally,si-Circ_0003855 and miR-622 inhibitor sequence(miR-622-inhibition)were co-transfected into cells with miR-622-inhibition alone,and untreated Eca109 cells were used as a control to detect the expression of FLOT1.Co-transfection of si-Circ_0003855 and miR-622-inhibition showed no significant difference in FLOT1 expression compared to the control cells(p>0.05).Synthesizing the results of these experiments above,we believe that interfering with the expression of Circ_0003855 can inhibit the activity of EC cells,and its mechanism is related to miR-622 and FLOT1.
