MicroRNA-218-5p accelerates malignant behaviors of breast cancer through LRIG1

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.

miRNA-218-5p increases cell sensitivity by inhibiting PRKDC activity in radiation-resistant lung carcinoma cells.

BACKGROUND: Non-small cell lung carcinoma (NSCLC) is a malignancy with the highest mortality rate. Currently, surgery combined with radiotherapy is the first choice in the clinical treatment of lung carcinoma (LC); however, long-term radiotherapy leads to radiation resistance in patients, resulting in treatment failure. METHODS: In this study, a new microRNA-218-5p (miRNA-218-5p) was identified, and its function in LC was investigated. RESULTS: Reverse transcription quantitative polymerase chain reaction (RT-qPCR) results revealed that miRNA-218-5p was downregulated in LC. Overexpression or inhibition of miRNA-218-5p in LC and targeted binding of protein kinase, DNA-activated, catalytic polypeptide (PRKDC) to miRNA-218-5p were confirmed by comprehensive bioinformatic analysis. Exosomes from A549 and H1299 cells were cocultured with miRNA-218-5p and then cotransfected into radiation-resistant A549R and H1299R cells; the proliferation of radiation-resistant LC cells was found to be effectively inhibited and apoptosis was induced. Overexpression of miRNA-218-5p and X-irradiation could enhance the radiosensitivity of LC cells. Exogenous miRNA-218-5p derived from A549 and H1299 cells could be transfected into radiation-resistant LC cells and could inhibit PRKDC expression, thus accelerating DNA damage, apoptosis, and radiation sensitization of LC cells. CONCLUSIONS: miRNA-218-5p could induce apoptosis and enhance the radiosensitivity of LC cells through regulatory activities, thus suggesting its application as a potential target for LC treatment.

MiRNA-218 inhibits cell proliferation, migration and invasion by targeting Runt-related transcription factor 2 (Runx2) in human osteosarcoma cells.

PURPOSE: The deregulation of miRNA-218 has been found in a number of cancers. Using miRNA-218 as a target for Runt-related transcription factor 2 (Runx2), we sought to understand the role of miRNA-218 in osteosarcoma (OS). METHODS: The expression of miRNA-218 was detected in the OS tumor tissues and OS cells. The Runx2 expression level was evaluated in Saos-2, 143B, U2OS, and MG-63. miRNA-218 overexpressed U2OS cells were achieved by transfection with miRNA-218 mimics. The role of miRNA-218 in inhibiting OS tumorigenesis was explored by CCK8, colony formation, cell wound scratch and Transwell assay. TargetScan and dual-luciferase reporter assay identified the interaction between miRNA-218 and Runx2. The inhibitive effect of miRNA-218 on OS through targeting Runx2 was also evaluated. RESULTS: MiRNA-218 levels were remarkably down-regulated in OS tumor tissues and cell lines. The overexpression of miRNA-218 suppressed U2OS cell development and metastasis. The target interaction between miRNA-218 and Runx2 was validated, and their expression showed a negative correlation in U2OS cells. The suppressed U2OS cell development and metastasis were remarkably reversed by Runx2 overexpression. CONCLUSION: MiRNA-218 showed an inhibitive effect on the development and metastasis of osteosarcoma cell proliferation by targeting Runx2. Our findings may provide novel clues for OS treatment.

Survivin is a prognostic indicator in glioblastoma and may be a target of microRNA-218.

Accumulating evidence has revealed that survivin expression is associated with a malignant phenotype and poor prognosis in glioma. Survivin is also a potential target of microRNA (miRNA/miR)-218. The aim of the present study was to investigate the expression and function of survivin in glioblastoma, and to examine the association between survivin and miR-218. For that purpose, survivin mRNA levels were analyzed in 144 frozen samples of glioblastoma using whole-genome RNA sequencing. In vitro cell proliferation, migration, invasion and apoptosis assays were performed, and survivin expression was detected by western blotting. The results revealed that the mRNA expression levels of survivin were negatively and significantly associated with overall survival in glioblastoma. Further in vitro analyses suggested that miR-218 may inhibit the expression of survivin. Expression of miR-218 in the LN229 cell line was significantly lower than that in the immortalized human gliocyte HEB cell line. miR-218 markedly inhibited tumor cell proliferation, migration and invasion capacities, and decreased apoptosis. miR-218 also inhibited the expression of survivin. These results indicated that survivin may be a target of miR-218 and could serve as a predictive biomarker.

Expression and clinical significance of miRNA-145 and miRNA-218 in laryngeal cancer.

Expression of miRNA-145 and miRNA-218 in serum of patients with laryngeal cancer and the relationship between them and the clinicopathological parameters and prognosis were investigated. The clinical medical records of 132 patients with laryngeal cancer, who were admitted to Guangdong Second Provincial General Hospital from February 2009 to March 2014, were retrospectively analyzed and comprised the study group. The data of physical examinations of 56 healthy volunteers who took physical examinations in the same hospital comprised the control group. RT-qPCR was used to detect the expression levels of miRNA-145 and miRNA-218 in serum of the patients in the two groups. According to the relative expression levels of miRNA-145 and miRNA-218 in serum of the patients in the study group on the day when they left hospital, the study group was divided into the high expression group (n=73 patients) and the low expression group (n=59 patients). The patients received a 48-month follow-up visit and their survival condition was recorded and the Kaplan-Meier was used to carry out the survival analysis. The expression levels of miRNA-145 and miRNA-218 in serum of the patients in the study group were lower than those in the control group (P<0.05). The median survival time of the patients in the high expression group was 30 months while the median survival time of the patients in the low expression group was 26 months. The expression levels of miRNA-145 and miRNA-218 in serum of patients with laryngeal cancer decreased, the higher the expression levels of miRNA-145 and miRNA-218 in serum of patients with laryngeal cancer were, the better the prognosis was. miRNA-145 and miRNA-218 were used as indicators of assessing the prognosis of patients with laryngeal cancer.

E2F1-mediated MNX1-AS1-miR-218-5p-SEC61A1 feedback loop contributes to the progression of colon adenocarcinoma.

The long noncoding RNA MNX1-AS1 has been reported to facilitate the progression of glioblastoma and ovarian cancer. Nevertheless, the biological roles and underlying mechanisms of MNX1-AS1 in colon adenocarcinoma have not been studied until now. In the current study, MNX1-AS1 was upregulated in colon adenocarcinoma. JASPAR prediction tool showed that E2F1 could bind to the promoter region of MNX1-AS1. The chromatin immunoprecipitation assay and luciferase reporter assay were used to verify the interactions between MNX1-AS1 and E2F1. Then functional assays revealed that downregulation of MNX1-AS1 decreased cell proliferation, migration, and invasion in colon adenocarcinoma, but upregulation of E2F1 reversed the effects. Moreover, subcellular fractionation assay manifested that MNX1-AS1 was enriched in the cytoplasm of colon adenocarcinoma cells, thus we speculated whether MNX1-AS1 could function as a competing endogenous RNA (ceRNA) to play roles in colon adenocarcinoma. Bioinformatics analysis and luciferase reporter assay indicated that MNX1-AS1 could sponge microRNA-218-5p (miR-218-5p). Furthermore, we discovered that SEC61A1 was downstream target of miR-218-5p, and MNX1-AS1 acted as a ceRNA to upregulate the expression of SEC61A1 through sponging miR-218-5p. Finally, rescue assays confirmed that MNX1-AS1 facilitated the progression of colon adenocarcinoma through regulating miR-218-5p/SEC61A1 axis. Taken together, we concluded that E2F1-mediated MNX1-AS1-miR-218-5p-SEC61A1 feedback loop contributed to the progression of colon adenocarcinoma.

miRNA-218-loaded carboxymethyl chitosan - Tocopherol nanoparticle to suppress the proliferation of gastrointestinal stromal tumor growth.

Gastrointestinal stromal tumors (GIST) are one of the most common forms of mesenchymal cancers of the gastrointestinal tract. Although chemotherapeutic drugs inhibited the proliferation of GIST, however, sizable proportion of people developed resistance and therefore difficult to treat. In the present study, O-carboxymethyl chitosan (OCMC)-tocopherol polymer conjugate was synthesized and formulated into stable polymeric nanoparticles. The main aim of present study was to increase the therapeutic efficacy of miR-218 in GIST. The mean size of nanoparticles was ~110nm with a spherical shape. The miR-218 NP has been shown inhibit the cell proliferation and exhibited a superior cell apoptosis. The miR-218 NP inhibited the cell invasion and promoted the apoptosis of GIST cancer cells. In the present study, we have successfully showed that KIT1 is the target gene of miR-218 as shown by the luciferase reporter assay. These findings collectively suggest the miR-218 loaded nanoparticle by virtue of effective transfection could act as a tumor suppressor miRNA in the treatment of GIST.

Effect of miRNA-218 on renal cell carcinoma in nude mice / 肿瘤研究与临床

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.

Expression of miR-218 in cervical cancer tissues and bioinformatics analysis of predicted target genes / 肿瘤研究与临床

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.