MicroRNAs (miRNAs) play a key role in tumor metastasis based on their capacity to regulate the expression of tumor-related genes. Over-expression of key genes such as c-MYC and CTNNB1 (encoding β-catenin) in Wnt/β-catenin-dependent and ROCK1 in Wnt/β-catenin-independent signaling pathways (Rho/Rho-associated kinase (ROCK) signaling pathway) has already been identified as the hallmarks of many tumors, and their role in breast cancer has also been investigated and confirmed. miR-340 characterization as an onco-suppressor miRNA has been previously reported. However, the mechanism by which it inhibits metastasis has not been completely elucidated. Quantitative real-time PCR (qPCR), Western blot, and luciferase assays were used to confirm the effect of miR-340 on the 3'-untranslated region (UTR) of the target genes. Lentiviral particles containing miR-340 were also used to evaluate the effect of miR-340 restoration on cell proliferation, migration, and invasion in vitro in the invasive MDA-MB-231 cell line. By applying bioinformatic approaches for the prediction of miRNAs targeting 3'-UTRs of CTNNB1, c-MYC, and ROCK1, we found out that miR-340 could dramatically down-regulate metastasis by targeting Wnt signaling in breast cancer cells. In the current study, analyzing miR-340 by reverse transcription quantitative PCR (RT-qPCR) in MDA-MB-231 showed that it was remarkably down-regulated in the metastatic breast cancer cell line. We found that restoration of miR-340 in the invasive breast cancer cell line, MDA-MB-231, suppresses the expression of the target genes' messenger RNA (mRNA) and protein and, as a result, inhibits tumor cell invasion and metastasis. Our findings highlight the ability of bioinformatic approaches to find miRNAs targeting specific genes. By bioinformatic analysis, we confirmed the important role of miR-340 as a pivotal regulator of breast cancer metastasis in targeting previously validated (ROCK1) and potentially novel genes, i.e., (CTNNB1 and c-MYC).

Development of a rapid and accurate quantification method for the detection of microRNAs (miRNAs) has been desired, in particular, when they are differently expressed in normal and pathological conditions. However, various methods for the quantification of small non-coding RNAs as well as miRNAs have been described. These methods mainly include hybridization-based approaches such as primer extension, northern blotting, microarray profiling, and reverse transcription (RT) PCR. Here, we developed a simple and rapid method based on stem-loop primer-based real-time PCR assay for sensitive and accurate detection of mature miRNAs. Initially, a miRNA-specific stem-loop RT primer is used for RT, which is followed by TaqMan real-time PCR assay using specific forward primer in combination with universal reverse primer and TaqMan probe. The assay has shown high sensitivity (≤50 copies/reaction) for miRNA detection in two breast cancer cell lines, MCF-7 and MDA-MB-231. This assay might be implicated as a rapid and cost effective method for the detection of small non-coding RNAs.

Mesenchymal stem cells (MSCs) are multipotent cells with the potential to differentiate into different cell types. Owing to their immunosuppressive and antiinflammatory properties, they are widely used in regenerative medicine, but they have a dual effect on cancer progression and exert both growth-stimulatory or -inhibitory effects on different cancer types. It has been proposed that these controversial effects of MSC in tumor microenvironment (TME) are mediated by their polarization to proinflammatory or anti-inflammatory phenotype. In addition, they can polarize the immune system cells that in turn influence tumor progression. One of the mechanisms involved in the TME communications is extracellular vesicles (EVs). MSCs, as one of cell populations in TME, produce a large amount of EVs that can influence tumor development. Similar to MSC, MSC-EVs can exert both anti-or protumorigenic effects. In the current study, we will investigate the current knowledge related to MSC role in cancer progression with a focus on the MSC-EV content in limiting tumor growth, angiogenesis, and metastasis. We suppose MSC-EVs can be used as safe vehicles for delivering antitumor agents to TME.

The most common endocrine malignancy is thyroid cancer, and researchers have made a great deal of progress in deciphering its molecular mechanisms in the recent years. Many of molecular changes observed in thyroid cancer can be used as biomarkers for diagnosis, prognosis, and therapeutic targets for treatment. MicroRNAs (miRNAs) are important parts in biological and metabolic pathways such as regulation of developmental stages, signal transduction, cell maintenance, and differentiation. Therefore, their dysregulation can expose individuals to malignancies. It has been proved that miRNA expression is dysregulated in different types of tumors, like thyroid cancers, and can be the cause of tumor initiation and progression. In this paper, we have reviewed the available data on miRNA dysregulation in different thyroid tumors including papillary, follicular, anaplastic, and medullary thyroid carcinomas aiming to introduce the last updates in miRNAs-thyroid cancer relation.

Many reports have indicated deregulation of a variety of microRNAs (miRNAs) in human cancers. In this study, we appraised miR-9 correlation with NOTCH1 involved in Notch signaling in metastatic breast cancer. The Notch signaling pathway has been approved to be associated with the development and progression of many human cancers, including breast cancer, but the precise mechanism has remained unknown. To the best of our knowledge, this is the first study that introduces miR-9 and NOTCH1 correlation as an effective factor in breast cancer. We found that miR-9 expression was decreased in MDA-MB-231 breast cancer cells compared with MCF-10A normal breast cell line. However, NOTCH1 was upregulated in the metastatic breast cancer cells. Furthermore, luciferase assay revealed a significant inverse correlation between miR-9 and NOTCH1. Overexpression of Notch signaling via Notch1 intracellular domain in MDA-MB-231 cell line was suppressed by lentiviruses expressing miR-9. Taken together, the results obtained by MTT, flow cytometry, migration, and wound healing assays showed that it is possible to inhibit metastasis and induce pro-apoptotic state by induction of miR-9 expression in MDA-MB-231 cells but with no effect on cell proliferation. These results shows that miR-9, by direct targeting of NOTCH1, can reveal a suppressor-like activity in metastatic breast cancer cells.

No abstract

No abstract

Hepatocellular carcinoma (HCC) is an invasive form of hepatic cancer arising from the accumulation of multiple genetic alterations. In this study, the causal role of disturbed canonical Wnt/β-catenin pathway was approved, and some of HCC-driven important gene candidates were determined. MicroRNAs (miRNAs), small non-coding RNAs, are the key regulators of important cancer genes, and their participation in tumorigenesis has been shown. By reviewing literature, WNT1 gene with functional significance was selected to approve miRNAs as new subjects for targeted therapy.For proper and fast miRNA detection and also confirmation of the role of bioinformatics in obtaining practical data, we benefited from different bioinformatics tools such as TargetScan, miRanda, and DIANA. In order to use an HCC model, we used HepG2 cell line. Luciferase assay was applied to assess the ability of the selected miRNAs in targeting WNT1 3'-UTR. To overexpress the selected miRNA in HepG2 cell line, viral construct was prepared. Quantitative real-time PCR was performed to evaluate selected miRNA and target gene expression levels. miR-122 was selected according to data concerning various bioinformatics tools.miR-122 was downregulated and WNT1 gene expression was upregulated in HepG2 cell line. After viral construct transduction, miR-122 expression was elevated and WNT1 expression was notably declined. Finally, we introduced WNT1 gene as one of the important genes in HCC, and also, we showed that miR-122 can regulate WNT1 gene expression.Moreover, our study determines the potential of bioinformatics analyses in providing accurate and reliable data for miRNA: messenger RNA (mRNA) prediction.