MiR‑592 acts as an oncogene and promotes medullary thyroid cancer tumorigenesis by targeting cyclin‑dependent kinase 8.
ABSTRACT: Medullary thyroid carcinoma (MTC) is a relatively rare subtype of thyroid cancer, accounting for 5‑10% of all cases of thyroid cancer worldwide. Due to the current lack of knowledge regarding the tumorigenesis of MTC, the clinical treatment of MTC remains a challenge. It has been reported that microRNAs (miRNAs) regulate the progression of MTC; however, the regulatory network of miRNAs and the exact underlying mechanisms are not completely understood. In the present study, an miRNA expression profile (GSE40807), consisting of 80 samples, was downloaded and analyzed using Gene Expression Omnibus‑2R to identify differentially expressed miRNAs between MTC and normal samples. miR‑592 expression levels were significantly increased in MTC tissues and cell lines compared with normal tissues and cell lines. Patients with high miR‑592 expression levels exhibited a less favorable prognosis compared with patients with low miR‑592 expression. The results suggested that miR‑592 overexpression promoted TT and MZ‑CRC‑1 cell proliferation in vitro. In addition, miR‑592 negatively regulated cyclin‑dependent kinase 8 (CDK8) via targeted binding in MTC cells. Moreover, co‑transfection of CDK8 overexpression plasmid and miR‑592 mimic reversed miR‑592‑mediated MTC cell proliferation. In conclusion, miR‑592 may serve as an oncogene in MTC by decreasing the expression of CDK8, indicating that the miR‑592/CDK8 axis might serve as a promising therapeutic target for MTC.
Project description:Colorectal cancer (CRC), one of the most common cancer types, causes a large number of cancer?related mortalities annually worldwide. Dysregulated microRNAs (miRNAs/miR) are closely associated with the malignant progression of CRC. Therefore, the present study aimed to investigate the expression and regulatory role of miR?592 in CRC. It was found that miR?592 expression was significantly elevated in CRC tissues and cell lines, and was associated with the prognosis of patients. Cellular phenotype assays demonstrated that miR?592 could promote CRC cell proliferation, migration and invasion. Bioinformatics analysis demonstrated that miR?592 mainly participated in the positive regulation of transcription, as well as the regulation of cell motility. Moreover, miR?592 targets were enriched in several signaling pathways, such as the 'mTOR' and 'FoxO' signaling pathways. In addition, secreted protein acidic and rich in cysteine (SPARC) was identified as a target of miR?592 in CRC. The present results suggested that miR?592 acts as an oncogene in CRC, in part, by directly inhibiting SPARC expression. Collectively, the present study provides a novel potential therapeutic strategy for CRC.
Project description:Thyroid cancers are the most common malignancy of the endocrine system; however, there is no reliable blood biomarkers for thyroid cancer diagnosis and even for aggressive and nonaggressive thyroid cancers as well as benign nodule discrimination. The present study is aimed at evaluating whether circulating microRNA (miRNA) can differentiate aggressive and nonaggressive thyroid cancer from benign thyroid nodules. In this study, we performed a multiphase, case-control study to screen serum miRNA expression profile in 100 patients with papillary thyroid cancer (PTC), 15 patients with aggressive medullary thyroid carcinoma (MTC), 91 patients with benign nodules, and 89 healthy controls using TaqMan low-density array followed by extensive reverse transcription quantitative real-time PCR validation. The results showed that the serum levels of miR-222-3p, miR-17-5p, and miR-451a were markedly increased, while miR-146a-5p, miR-132-3p, and miR-183-3p were significantly decreased in the PTC and benign nodule groups compared with the control group. There was no difference in the miRNA expression profile between the PTC group and the benign nodule group. Nevertheless, the serum levels of miR-222-3p and miR-17-5p were significantly increased in the MTC group than the benign nodule and control group. Moreover, receiver operating characteristic curve analyses demonstrated that the 2 miRNAs and their panel can accurately discriminate MTC from the benign nodule group and healthy controls. These findings indicated that the altered circulating miRNAs may discriminate PTC and benign thyroid nodules from controls, and serum miR-222-3p and miR-17-5p have the potential to serve as auxiliary tools for diagnosing more aggressive thyroid carcinomas, such as MTC.
Project description:BACKGROUND Medullary thyroid carcinoma (MTC), a rare type of thyroid cancer, is a big challenge in clinical treatment. However, the pathogenesis of MTC remains poorly understand. MicroRNAs (miRNAs) were previously demonstrated to be involved in the pathogenesis of MTC, however, the roles of majority of miRNAs in MTC are still undetermined. MATERIAL AND METHODS Two GEO miRNA expression profiles (GSE40807, GSE97070) were downloaded, and the differentially expressed miRNAs (DEmiRNAs) of GSE40807 and GSE97070 were analyzed by bioinformatics methods. Expressions of miRNAs were detected by quantitative real-time polymerase chain reaction; cell proliferation was examined through Cell Counting Kit-8, colony formation and in vivo tumor growth assays; the interaction between miRNA and mRNA was verified by dual-luciferase reporter assay; functional analysis of target genes was performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID, www.david.ncifcrf.gov) software. RESULTS Ten miRNAs were identified to be dysregulated in both GSE40807 and GSE97070 datasets, and miR-31-3p showed the highest change fold (Log fold change=-3.460625 in GSE40807 and Log fold change=-0.07084374 in GSE97070). MiR-31-3p expression was significantly downregulated in MTC, and low miR-31-3p expression showed a poor prognosis relative to high miR-31-3p expression (P<0.05). Functionally, miR-31-3p inhibited MTC cell proliferation in vitro and in vivo. Functional analysis also showed that the target genes of miR-31-3p were involved in numerous of biochemical processes and pathways, of which Ras signaling pathway was selected for further study. RASA2, overexpressed in MTC, were negatively regulated by miR-31-3p. In addition, we found that knockdown of RASA2 inhibited MTC cell proliferation. CONCLUSIONS Reduced expression level of miR-31-3p might play a key role in the tumorigenesis of MTC by targeting critical pathways, especially Ras signaling pathway.
Project description:Colorectal cancer (CRC) is the second leading cause of cancer-associated mortality worldwide. Currently, available diagnostic biomarkers are neither sensitive nor specific. Thus, the present study aimed to identify novel circulating microRNAs (miRNAs) as biomarkers for the early diagnosis of CRC. All samples were provided by The Second Affiliated Hospital of Nanjing Medical University (Nanjing, China). Analysis of the GSE108153 and GSE55139 datasets, downloaded from the Gene Expression Omnibus (GEO) database was performed using the online tool, GEO2R. Reverse transcription-quantitative PCR was performed to determine miR-592 expression in CRC tissues, cells and serums of patients. Subsequently, the diagnostic value of serum miR-592 was assessed via receiver operating characteristic (ROC) curve analysis. Both the assessment of clinical samples and bioinformatics analysis demonstrated that miR-592 expression levels were significantly upregulated in the tissues and serum of patients with CRC, suggesting that elevated serum miR-592 may be tumor-derived. ROC analysis indicated that serum miR-592 levels may differentiate patients with early stage CRC and advanced adenoma from healthy individuals, with area under the curve values of 0.801 and 0.747, respectively. Taken together, the results of the present study suggest that serum miR-592 may be implicated as a potential biomarker for the early diagnosis of CRC.
Project description:In this study, we performed microRNA (miRNA) expression profiling on a large series of sporadic and hereditary forms of medullary thyroid carcinomas (MTC). More than 60 miRNAs were significantly deregulated in tumor vs adjacent non-tumor tissues, partially overlapping with results of previous studies. We focused our attention on the strongest up-regulated miRNA in MTC samples, miR-375, the deregulation of which has been previously observed in a variety of human malignancies including MTC. We identified miR-375 targets by combining gene expression signatures from human MTC (TT) and normal follicular (Nthy-ori 3-1) cell lines transfected with an antagomiR-375 inhibitor or a miR-375 mimic, respectively, and from an in silico analysis of thyroid cell lines of Cancer Cell Line Encyclopedia datasets. This approach identified SEC23A as a bona fide miR-375 target, which we validated by immunoblotting and immunohistochemistry of non-tumor and pathological thyroid tissue. Furthermore, we observed that miR-375 overexpression was associated with decreased cell proliferation and synergistically increased sensitivity to vandetanib, the clinically relevant treatment of metastatic MTC. We found that miR-375 increased PARP cleavage and decreased AKT phosphorylation, affecting both cell proliferation and viability. We confirmed these results through SEC23A direct silencing in combination with vandetanib, highlighting the importance of SEC23A in the miR-375-associated increased sensitivity to vandetanib.Since the combination of increased expression of miR-375 and decreased expression of SEC23A point to sensitivity to vandetanib, we question if the expression levels of miR-375 and SEC23A should be evaluated as an indicator of eligibility for treatment of MTC patients with vandetanib.
Project description:BACKGROUND: MicroRNAs (miRNAs) are involved in the pathogenesis of human cancers, including medullary thyroid carcinoma (MTC). The aim of this study was to test the hypothesis that different miRNA profiles are related to RET status and prognosis in patients with hereditary MTC (hMTC) and sporadic MTC (sMTC). METHODS: We analyzed the expression of nine miRNAs (miR-21, miR-127, miR-154, miR-224, miR-323, miR-370, miR-9*, miR-183, and miR-375) by quantitative real-time-polymerase chain reaction in 34 cases of sMTC, 6 cases of hMTC, and 2 cases of C-cell hyperplasia (CCH). We also analyzed the immunohistochemical expression of PDCD4, an miR-21 gene target. sMTC (n=34) was genotyped for somatic RET and RAS mutations. Disease status was defined on the basis of the concentration of serum calcitonin at the latest follow-up and other parameters as indicated in the results. RESULTS: MTC and CCH were both characterized by a significant overexpression of the whole set of miRNAs (the increase being 4.2-fold for miR-21, 6.7-fold for miR-127, 8.8-fold for miR-154, 6.6-fold for miR-224, 5.8-fold for miR-323, 6.1-fold for miR-370, 13-fold for miR-9*, 6.7-fold for miR-183, and 10.1 for miR-375, p<0.0001). PDCD4 expression was significantly downregulated in MTC samples, consistent with miR-21 upregulation. Significantly lower miR-127 levels were observed in sMTC carrying somatic RET mutations in comparison to sMTC carrying a wild-type RET. In sMTC and familial MTC, the miR-224 upregulation correlated with the absence of node metastases, lower stages at diagnosis, and with biochemical cure during follow-up. CONCLUSIONS: miRNAs are significantly dysregulated in MTC, and this dysregulation is probably an early event in C-cell carcinogenesis. miR-224 upregulation could represent a prognostic biomarker associated with a better outcome in MTC patients.
Project description:Hepatocellular carcinoma (HCC) cells rapidly switch their energy source from oxidative phosphorylation to glycolytic metabolism in order to efficiently proliferate. However, the molecular mechanisms responsible for this switch remain unclear. In this study, we found that miR-592 was frequently downregulated in human HCC tissues and cell lines, and its downregulation was closely correlated with aggressive clinicopathological features and poor prognosis of HCC patients. Overexpression of miR-592 inhibited aerobic glycolysis and proliferation in HCC cells in vitro. Conversely, knockdown of miR-592 promoted HCC growth in both subcutaneous injection and orthotopic liver tumor implantation models in vivo. Mechanistically, miR-592 downregulation in human HCCs was correlated with an upregulation of WD repeat and SOCS box containing 1 (WSB1). We further showed that miR-592 directly binds to the 3'-UTR of the WSB1 gene, thus disrupting hypoxia inducible factor-1? (HIF-1?) protein stabilization. In turn, overexpression of WSB1 in HCC cells rescued decreased HIF-1? expression, glucose uptake, and HCC growth induced by miR-592. Collectively, our clinical data and functional studies suggest that miR-592 is a new robust inhibitor of the Warburg effect and a promising therapeutic target for HCC treatment.
Project description:Micro-RNAs are dysregulated in medullary thyroid carcinoma (MTC) and preliminary studies have shown that miRNAs may enact a therapeutic effect through changes in autophagic flux. Our aim was to study the in vitro effect of miR-9-3p on MTC cell viability, autophagy and to investigate the mRNA autophagy gene profile of sporadic versus hereditary MTC. The therapeutic role of miR-9-3p was investigated in vitro using human MTC cell lines (TT and MZ-CRC-1 cells), cell viability assays, and functional mechanism studies with a focus on cell cycle, apoptosis, and autophagy. Post-miR-9-3p transfection mRNA profiling of cell lines was performed using a customized, quantitative RT-PCR gene array card. This card was also run on clinical tumor samples (sporadic: n = 6; hereditary: n = 6) and correlated with clinical data. Mir-9-3p transfection resulted in reduced in vitro cell viability; an effect mediated through autophagy inhibition. This was accompanied by evidence of G2 arrest in the TT cell line and increased apoptosis in both cell lines. Atg5 was validated as a predicted miR-9-3p mRNA target in TT cells. Post-miR-9-3p transfection array studies showed a significant global decline in autophagy gene expression (most notably in PIK3C3, mTOR, and LAMP-1). Autophagy gene mRNAs were generally overexpressed in sporadic (vs. hereditary MTC) and Beclin-1 overexpression was shown to correlate with residual disease. Autophagy is a tumor cell survival mechanism in MTC that when disabled, is of therapeutic advantage. Beclin-1 expression may be a useful prognostic biomarker of aggressive disease.
Project description:<h4>Background</h4>Medullary thyroid cancer (MTC) represents 13.4 % of all thyroid cancers-related deaths. The treatments for MTC are very limited especially for patients with distal metastasis. Therefore, it is critical to understand the mechanisms of MTC to pursue novel therapeutic avenues. Here, we studied the function of circPVT1/miR-455-5p in MTC.<h4>Methods</h4>Human MTC tissues and cell lines were used. qRT-PCR and Western blotting were employed to measure expression levels of miR-455-5p, circPVT1, CXCL12, and epithelial mesenchymal transformation (EMT)-related proteins. Colony formation assay, flow cytometry, transwell assay, and scratch wound healing assay were used to assess the abilities of cell proliferation, apoptosis, migration and invasion, respectively. Dual luciferase assay and RNA immunoprecipitation were employed to validate interactions of circPVT1/miR-455-5p and miR-455-5p/CXCL12. Nude mouse xenograft model was used to evaluate the effects of shcircPVT1 and miR-455-5p mimics on tumor growth and metastasis in vivo.<h4>Results</h4>miR-455-5p was reduced in MTC tissues and cells while circPVT1 was elevated. Their levels were correlated with prognosis of MTC. Overexpression of miR-455-5p or sh-circPVT1 suppressed EMT and MTC cell proliferation, migration and invasion. miR-455-5p targeted CXCL12 while circPVT1 sponged miR-455-5p. Knockdown of CXCL12 or CXCL12/CXCR4 signaling inhibitor reversed the effects of circPVT1 overexpression or miR-455-5p inhibitor on EMT and MTC cell proliferation, migration and invasion. Knockdown of circPVT1 or miR-455-5p overexpression repressed MTC tumor growth and lung metastasis in vivo.<h4>Conclusions</h4>miR-455-5p suppresses MTC growth and metastasis by targeting CXCL12/CXCR4 signaling pathway while circPVT1 promotes MTC by sponging miR-455-5p. Our study sheds light on the mechanisms of MTC growth and metastasis.
Project description:Previous studies have shown that miR-592 may play an important role in the development of various cancer types. However, the mechanism of miR-592 in breast cancer progression remains unclear. Functional analysis showed that overexpression of miR-592 significantly inhibited the cell proliferation, clonal formation, and migration and invasion of MCF-7 cells in vitro. RNA sequencing (RNA-seq) was then used to identify the significantly dysregulated genes and enriched pathways in response to miR-592 overexpression in MCF-7 cells. Overall design: MCF-7 cells transfected with miR-592 mimics were the treatment group, and MCF-7 cells transfected with mimics NC were used as controls. Experiments were performed in duplicate. Gene expression profiling analyses by high throughput sequencing were performed on mRNA samples isolated from the MCF-7 cells transfected with miR-592 mimics (592mic) and MCF-7 cells transfected with mimics NC(592micNC).