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Abstract Objective: MicroRNAs play crucial roles in the pathogenesis of cancers. MiRNA-218-5p may act as either an oncogene or a tumor suppressor, but its role in the pathogenesis of Breast Cancer (BC) remains unclear. Methods: Infiltrative breast ductal carcinoma as well as corresponding adjacent normal samples were collected from 30 patients. Mimics and inhibitors of miRNA-218-5p or corresponding negative controls were transfected into BC cells. miRNA-218-5p expression was detected by quantitative PCR. The effects of miRNA-218-5p on the malignant behaviors of BC were assessed. Dual-luciferase reporter assay was employed to evaluate the binding of miRNA-218-5p to LRIG1. Results: BC tissues showed higher miRNA-218-5p expression as compared to the adjacent normal tissues. Ectopic miRNA-218-5p expression accelerated the cell cycle, cell growth and migration of BC, while repressed cell apoptosis. Interestingly, ectopic miRNA-218-5p expression down-regulated LRIG1 expression, and miRNA-218-5p could bind to LRIG1. Also, our study indicated that miRNA-218-5p up-regulated ErbB2 and EGFR expression by targeting LRIG1, suggesting that the LRIG1-mediated signaling pathway contributed to the pro-tumor effects of miRNA-218-5p on BC. Conclusion: MiRNA-218-5p up-regulates ErbB2 and EGFR expression by suppressing LRIG1 expression, thus promoting the malignant behaviors of BC. miRNA-218-5p may exert a pro-tumor effect on BC and serve as a therapeutic target for BC treatment.
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Objective To explore the effects of miRNA-218 on renal cell carcinoma of nude mice in vivo.Methods The pcDNA3.1-miR-218 and its control negative plasmids were stably transfected into renal cell carcinoma cell line A498 and 769-P.These cells were inoculated into nude mice in different groups to observe the changes of body and tumor and to detect the expression of miR-218 in the tissues of nude mice.Results In the A498 cells + pcDNA3.1-miR-218 transfected group,the weight loss of tumor bearing nude mice after 25 days was lower than that in the control group,and the tumor volume was smaller than that in the control group after 10 days (P ＜ 0.05).In the 769-P cells + pcDNA3.1-miR-218 transfected group,the weight loss of tumor bearing nude mice was lower than that in the control group after 19 days,and the tumor volume was smaller than that in control group after 10 days (P ＜ 0.05).The expression of miRNA-218 in bearing nude mice with A498 cells or 769-P cells transfected by miRNA-218 was significantly higher than that in the control group,and the difference was statistically significant (P ＜ 0.05).Conclusion Up-regulation of miRNA-218 expression can inhibit the growth of renal cell carcinoma of nude mice in vivo.
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Objective To investigate the expression of miR-218 in cervical cancer tissues and bioinformatically analyze the target genes of miR-218 to provide theoretical basis on further studies of miR-218 functions in cervical cancer.Methods miRNA array was applied to detect miRNA expression profile in cervical cancer tissues,and real-time RT-PCR was used for validation.The bioinformatic analysis of the target genes of miR-218 involved gene ontology and signal transduction pathway enrichment was performed.Results miR-218 expression significantly decreased in cervical cancer tissues compared with that of normal cervical tissues.The functions of predicted target genes of miR-218 were enriched in biological regulation,adhesion and motion,proteometabolism,cellular differentiation,protein binding and other biological processes and molecular functions.According KEGG pathway database,the predicted target genes involved in pathway in cancer,adherent junction,focal adhesion,prostate cancer,chronic myeloid leukemia,melanoma,and other signal transduction pathways.Conclusions miR-218 expression significantly decreases in cervical cancer tissues.Some of the predicted target genes of miR-218 are significantly enriched in tumor related with signaling pathways.