406940

MIR148A

Recent studies have implied that miRNAs act as crucial modulators for epithelial-to-mesenchymal transition (EMT). We found that miR-148a is significantly downregulated in non-small cell lung cancer (NSCLC) compared to adjacent non-cancerous lung tissues, and the downregulated miR-148a was significantly associated with lymph-node metastasis. Functional assays demonstrated that miR-148a inhibited EMT in NSCLC cells. Moreover, miR-148a decreased 3'-untranslated region luciferase activity of ROCK1 and ROCK1 protein expression. Knockdown of ROCK1 reversed EMT resembling that of miR-148a overexpression. Furthermore, ROCK1 was widely upregulated in NSCLC, and its mRNA levels were inversely correlated with miR-148a expression. These findings suggest that miR-148a acts as a novel EMT suppressor in NSCLC cells, at least in part by modulation of ROCK1.

MicroRNAs (miRNAs) are important regulators of gastric cancer development and progression. miR-148a is one of the most frequently and highly downregulated miRNAs in gastric cancer and is associated with advanced clinical stage and poor prognosis. In this study, we investigated the role of miR-148a in gastric cancer metastasis. Levels of miR-148a were determined by qRT-PCR in 60 gastric cancer samples. Cell migration and invasion assays were performed in a stably expressing miRNA-148a gastric cancer cell line established using a lentivirus expression system. epithelial-mesenchymal transition (EMT) was evaluated using qRT-PCR and Western Blots to detect epithelial marker E-cadherin and mesenchymal marker, vimentin. Luciferase reporter assays were used to identify downstream targets and biological function of miR-148a. Gastric cancer tissue had significantly lower expression of miR-148a compared to non-tumor tissue. Low miR-148a levels were associated with lymph node metastasis, N stage, and blood vessel invasion. miR-148a overexpression inhibited metastasis of gastric cancer cells. miR-148a overexpression also downregulated vimentin expression and upregulated E-cadherin expression, suggesting that miR-148a inhibited EMT. Finally, the SMAD2 gene was identified as the direct and functional target of miR-148a. MiR-148a suppresses gastric cancer metastasis and EMT, likely via SMAD2. Restoration of miR-148a expression could have important implications in gastric cancer therapy.

Metastasis is responsible for the rapid recurrence and poor survival of malignancies. epithelial-mesenchymal transition (EMT) has a critical role in metastasis. Increasing evidence indicates that EMT can be regulated by microRNAs (miRNAs). miR-148a is a liver-abundant miRNA. However, the role of miR-148a in the development of liver cancer remains largely unknown. In this study, we found that, compared with normal livers, miR-148a was significantly decreased in hepatocellular carcinoma (HCC) tissues, especially in those with the portal vein tumor thrombus. An in vitro transwell assay and an in vivo orthotopic liver xenograft model showed that the restoration of miR-148a expression significantly repressed the migration and pulmonary metastasis of hepatoma cells. Linear regression analysis revealed a positive correlation between the expression of miR-148a and the mRNA level of E-cadherin gene in human HCC tissues. Both gain- and loss-of-function studies disclosed that miR-148a promoted the expression of epithelial marker (E-cadherin) and reduced the levels of mesenchymal markers (N-cadherin, fibronectin or vimentin) in hepatoma cells. These data suggest that miR-148a may suppress EMT and cancer metastasis. Further mechanistic investigations showed that miR-148a directly inhibited Met expression by binding to its 3'-UTR. Moreover, the reintroduction of miR-148a attenuated the downstream signaling of Met, like activated phosphorylation of AKT-Ser473 and inhibitory phosphorylation of GSK-3beta-Ser9, and consequently reduced the nuclear accumulation of Snail, a transcription factor that promotes EMT. Taken together, miR-148a may negatively regulate Met/Snail signaling and therefore inhibit the EMT and metastasis of hepatoma cells. These findings highlight the significance of miR-148a downregulation in tumor progression and implicate miR-148a as an attractive candidate for cancer therapy.

PURPOSE: The purpose of this study was to determine microRNA expression in vitreous and subretinal fluid (SRF) samples from patients with retinal detachment (RD). The pathological importance of the identified microRNA transcript levels was analyzed in vitro. METHODS: Vitreous fluid was collected from 10 patients with macular hole (MH), vitreomacular traction syndrome (VMTS), or foveoschisis and from 11 patients with RD. Subretinal fluid was collected from 7 patients with RD. Of these, blood serum was collected in 4 patients. MicroRNA microarray profiling was performed to identify microRNA transcripts that were present in vitreous fluid, and more redundantly detected in SRF, of patients with RD, but not detected in control eyes. Western blotting and scratch assays were performed in ARPE-19 cells and primary human RPE cell lines transfected with microRNA to elucidate the effect of identified microRNA transcripts on epithelial-mesenchymal transition (EMT). RESULTS: MicroRNA microarray profiling revealed that hsa-miR-148a-3p was the most redundantly detected transcript in SRF and vitreous fluid from patients with RD, but not those with the other diseases. expression levels of hsa-miR-148a-3p were higher in SRF samples than in blood serum samples in 3 out of 4 patients. Following hsa-miR-148a-3p mimic transfection, ARPE-19 and human RPE cells demonstrated increased expression of alpha-smooth muscle actin by Western blotting and increased migration ability during scratch assays. CONCLUSIONS: The results of the present study indicate that hsa-miR-148a-3p was specifically detected in RD and promotes EMT in RPE.

epithelial-mesenchymal transition (EMT) plays a critical role in the process of cancer invasion and metastasis. The Wnt/beta-catenin signaling pathway is known as a stimulative factor, which may trigger EMT and metastasis of cancer cells. In addition, several microRNAs (miRNAs) have been proven to regulate the EMT process. Recent research revealed that miR148a is downregulated in pancreatic cancer. However, the definite role of miR-148a in EMT and invasion of pancreatic cancer is still unknown. The present study attempted to demonstrate the underlying mechanism of miR-148a in the regulation of EMT and invasion of pancreatic cancer cells. Our data revealed that the expression of miR-148a was markedly downregulated in human pancreatic ductal adenocarcinoma (PDAC) cell lines and tissues. In addition, the downregulation of miR-148a was associated with poor prognosis and EMT phenotype. Furthermore, restoration of miR-148a expression inhibited the EMT process, as well as the migration and invasion of BxPC-3 pancreatic cancer cells. Wnt10b, a promoting molecule of the Wnt/beta-catenin signaling pathway, was demonstrated by dualluciferase reporter assay to be a direct target of miR148a. Subsequently, we found that miR148a negatively regulated the protein expression of beta-catenin, cyclin D1 and MMP-9, which were important components of the Wnt/beta-catenin signaling pathway. In conclusion, these findings revealed that miR-148a suppresses EMT and invasion of pancreatic cancer cells by targeting Wnt10b and inhibiting the Wnt/beta-catenin signaling pathway, and thus, miR-148a may serve as a novel therapeutic target for pancreatic cancer.

BACKGROUND: MiRNAs are often deregulated in colorectal cancer and might function as tumor suppressors or as oncogenes. They participate in controlling key signaling pathways involved in proliferation, invasion and apoptosis and may serve as prognostic and predictive markers. In this study we aimed to evaluate the role of miRNA-148a and miRNA-625-3p in metastatic colorectal cancer. METHODS: Fifty-four patients with a first-time diagnosed CRC receiving FOLFOX +/- Bevacizumab were involved in the study. tumor samples underwent routine pathology examination including evaluation for tumor budding and KRAS. MiRNA-148a and miRNA-625-3p expression analysis was done by RT-PCR. Associations between expression of both miRNAs and clinico-pathological factors, treatment outcomes and survival were analyzed. RESULTS: Both miRNA-148a and miRNA-625-3p were down-regulated in the tumors compared to normal colonic mucosa. Significantly lower expression of both miRNAs was noticed in tumors with budding phenomenon compared to tumors without it (median values of miRNA-148a were 0.314 and 0.753 respectively, p = 0.011, and 0.404 and 0.620 respectively for miRNA-625-3p, p = 0.036). Significantly lower expression of miRNA-625-3p was detected in rectal tumors, compared to tumors in the colon (median 0.390 and 0.665 respectively, p = 0.037). Progression free survival was significantly lower in patients with high miRNA-148a expression (6 and 9 months respectively, p = 0.033), but there were no significant differences in PFS for miRNA-625-3p and in overall survival for both miRNAs. CONCLUSIONS: There was a significant relationship between low miRNA-148a and miRNA-625-3p expression and tumor budding, which is thought to represent epithelial-mesenchymal transition. Both studied miRNAs may be associated with a more aggressive phenotype and could be the potential prognostic and predictive biomarkers in CRC. Further investigation is needed to confirm miRNAs involvement in EMT, and their prognostic and predictive value.