Locked nucleic acid inhibits miR-92a-3p in human colorectal cancer, induces apoptosis and inhibits cell proliferation

Unique miRNA Expression Profile in MSI- and EMAST-Unstable Sporadic Colon Cancer

MicroRNAs (miRNAs) are critical post-transcriptional gene regulators and their involvement in sporadic colon cancer (CRC) tumorigenesis has been confirmed. In this study we investigated differences in miRNA expression in microsatellite stable (MSS/EMAST-S), microsatellite unstable marked by high elevated microsatellite alterations at selected tetranucleotide repeats (MSS/EMAST-H), and high microsatellite unstable (MSI-H/EMAST-H) tumor subgroups as well as in tumors with different clinicopathologic characteristics. An RT-qPCR analysis of miRNA expression was carried out on 45 colon cancer and adjacent normal tissue samples (15 of each group). Overall, we found three differentially expressed miRNAs between the subgroups. miR-92a-3p and miR-224-5p were significantly downregulated in MSI-H/EMAST-H tumors in comparison to other subgroups. miR-518c-3p was significantly upregulated in MSS/EMAST-H tumors in comparison to stable and highly unstable tumors. Furthermore, we showed that miR-143-3p and miR-145-5p were downregulated in tumors in comparison to normal tissues in all subgroups. In addition, we showed overexpression of miR-125b-5p in well-differentiated tumors and miR-451a in less advanced tumors. This is the first report on differences in miRNA expression profiles between MSS/EMAST-S, MSS/EMAST-H, and MSI-H/EMAST-H colorectal cancers. Our findings indicate that the miRNA expression signatures differ in CRC subgroups based on their instability status.

Role of microRNAs deregulation in initiation of rheumatoid arthritis: A retrospective observational study

Rheumatoid arthritis (RA) is a joint disorder and is considered an important public health concern nowadays. So, identifying novel biomarkers and treatment modalities is urgently needed to improve the health standard of RA patients. Factors involved in RA pathogenesis are genetic/epigenetic modification, environment, and lifestyle. In the case of epigenetic modification, the expression deregulation of microRNAs and the role of histone deacetylase (HDAC) in RA is an important aspect that needs to be addressed. The present study is designed to evaluate the expression pattern of microRNAs related to the HDAC family. Five microRNAs, miR-92a-3p, miR-455-3p, miR-222, miR-140, and miR-146a related to the HDAC family were selected for the present study. Real-time polymerase chain reaction was used to estimate the level of expression of the above-mentioned microRNAs in 150 patients of RA versus 150 controls. Oxidative stress level and histone deacetylation status were measured using the enzyme-linked immunosorbent assay. Statistical analysis showed significant downregulation (P < .0001) of selected microRNAs in RA patients versus controls. Significantly raised level of HDAC (P < .0001) and 8-hydroxy-2'-deoxyguanosine (P < .0001) was observed in patients versus controls. A good diagnostic potential of selected microRNAs in RA was shown by the receiver operating curve analysis. The current study showed a significant role of deregulated expression of the above-mentioned microRNAs in RA initiation and can act as an excellent diagnostic marker for this disease.

Targeting miRNA by CRISPR/Cas in cancer: advantages and challenges

Clustered regulatory interspaced short palindromic repeats (CRISPR) has changed biomedical research and provided entirely new models to analyze every aspect of biomedical sciences during the last decade. In the study of cancer, the CRISPR/CRISPR-associated protein (Cas) system opens new avenues into issues that were once unknown in our knowledge of the noncoding genome, tumor heterogeneity, and precision medicines. CRISPR/Cas-based gene-editing technology now allows for the precise and permanent targeting of mutations and provides an opportunity to target small non-coding RNAs such as microRNAs (miRNAs). However, the development of effective and safe cancer gene editing therapy is highly dependent on proper design to be innocuous to normal cells and prevent introducing other abnormalities. This study aims to highlight the cutting-edge approaches in cancer-gene editing therapy based on the CRISPR/Cas technology to target miRNAs in cancer therapy. Furthermore, we highlight the potential challenges in CRISPR/Cas-mediated miRNA gene editing and offer advanced strategies to overcome them.

DNA methylation and miR-92a-3p-mediated repression of HIP1R promotes pancreatic cancer progression by activating the PI3K/AKT pathway

Pancreatic cancer (PAAD) is a highly malignant tumour characterized of high mortality and poor prognosis. Huntingtin-interacting protein 1-related (HIP1R) has been recognized as a tumour suppressor in gastric cancer, while its biological function in PAAD remains to be elucidated. In this study, we reported the downregulation of HIP1R in PAAD tissues and cell lines, and the overexpression of HIP1R suppressed the proliferation, migration and invasion of PAAD cells, while silencing HIP1R showed the opposite effects. DNA methylation analysis revealed that the promoter region of HIP1R was heavily methylated in PAAD cell lines when compared to the normal pancreatic duct epithelial cells. A DNA methylation inhibitor 5-AZA increased the expression of HIP1R in PAAD cells. 5-AZA treatment also inhibited the proliferation, migration and invasion, and induced apoptosis in PAAD cell lines, which could be attenuated by HIP1R silencing. We further demonstrated that HIP1R was negatively regulated by miR-92a-3p, which modulates the malignant phenotype of PAAD cells in vitro and the tumorigenesis in vivo. The miR-92a-3p/HIP1R axis could regulate PI3K/AKT pathway in PAAD cells. Taken together, our data suggest that targeting DNA methylation and miR-92a-3p-mediated repression of HIP1R could serve as novel therapeutic strategies for PAAD treatment.

Locked nucleic acid (LNA): A modern approach to cancer diagnosis and treatment

Cancer is responsible for about one in six deaths in the world. Conventional cancer treatments like chemotherapy, radiotherapy, and surgery are associated with drug poisoning and poor prognosis. Thanks to advances in RNA delivery and target selection, new cancer medicines are now conceivable to improve the quality of life and extend the lives of cancer patients. Antisense oligonucleotides (ASOs) and siRNAs are the most important tools in RNA therapies. Locked Nucleic Acids (LNAs) are one of the newest RNA analogs, exhibiting more affinity to binding, sequence specificity, thermal stability, and nuclease resistance due to their unique properties. Assays using LNA are also used in molecular diagnostic methods and provide accurate and rapid mutation detection that improves specificity and sensitivity. This study aims to review the special properties of LNA oligonucleotides that make them safe and effective antisense drugs for cancer treatment by controlling gene expression. Following that, we go over all of the molecular detection methods and cancer treatment antisense tactics that are possible with LNA technology.

HBV Promotes the Proliferation of Liver Cancer Cells through the hsa_circ_0000847/miR-135a Pathway

Hepatocellular carcinoma (HCC) is currently one of the most common tumors, with a high morbidity and mortality rate. HCC induced by persistent hepatitis B virus (HBV) infection is the most common liver cancer subtype at present, and HBV-related HCC is highly malignant and its development mechanism still needs to be explored in depth. This study aimed to explore the molecular mechanism of hsa_circ_0000847 targeting miR-135a-5p (miR-135a) to regulate the proliferation, invasion, and apoptosis of liver cancer cells. The study found that the expression level of hsa_circ_0000847 in liver cancer tissues and cells was significantly increased, while the expression level of miR-135a was significantly decreased. Hsa_circ_0000847 promoted the proliferation of liver cancer cells and elevated the expression of the proliferation-related protein. In addition, hsa_circ_0000847 could promote the invasion of HBV-infected liver cancer cells and inhibit the cell apoptosis of liver cancer cells. At the same time, it significantly promoted the expression of antiapoptotic proteins and inhibited the expression of proapoptotic protein. Interestingly, the dual luciferase experiment proved that hsa_circ_0000847 directly targeted miR-135a. On the other hand, the combined effect of hsa_circ_0000847 and miR-135a further illustrated the effect of hsa_circ_0000847 on the proliferation, invasion, and apoptosis of liver cancer cells. In addition, further experiments have also found that HBV could promote the expression of p-p38, p-ERK, and p-JNK through the hsa_circ_0000847/miR-135a axis, thereby further activating the MAPK pathway. In short, HBV promotes the proliferation and invasion of liver cancer cells and inhibits apoptosis by regulating the hsa_circ_0000847/miR-135a pathway, which provided a theoretical basis for effective treatment of HBV-infected liver cancers.

Ratiometric Fluorescent Biosensor Based on Self-Assembled Fluorescent Gold Nanoparticles and Duplex-Specific Nuclease-Assisted Signal Amplification for Sensitive Detection of Exosomal miRNA

The sensitive detection of cancer-associated exosomal microRNAs shows enormous potential in cancer diagnosis. Herein, a ratiometric fluorescent biosensor based on self-assembled fluorescent gold nanoparticles (Au NPs) and duplex-specific nuclease (DSN)-assisted signal amplification was fabricated for sensitive detection of colorectal cancer (CRC)-associated exosomal miR-92a-3p. In this biosensing system, the hairpin DNA modified with sulfhydryl and fluorescent dye Atto-425 at both ends is conjugated to fluorescent Au NPs through Au-S bonds, resulting in the quenching of Atto-425. The miR-92a-3p can open the hairpin of DNA and forms an miR-92a-3p/DNA heteroduplex, triggering the specific cleavage of DSN for the DNA in the heteroduplex. As a result, Atto-425 leaves the fluorescent Au NPs and recovers the fluorescence emission. The released miR-92a-3p can hybridize with another hairpin DNA and lead to a stronger fluorescence recovery of Atto-425 to form a signal amplification cycle. The stable fluorescence of Au NPs and the changing fluorescence of Atto-425 constitute a ratiometric fluorescent system reflecting the concentration of miR-92a-3p. This biosensor exhibits excellent specificity and can distinguish CRC patients from healthy individuals by detecting miR-92a-3p extracted from clinical exosome samples, showing the potential in CRC diagnosis.

MicroRNAs Are Key Molecules Involved in the Gene Regulation Network of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common types of cancer and one of the leading causes of mortality worldwide. MicroRNAs (miRNAs) play central roles in normal cell maintenance, development, and other physiological processes. Growing evidence has illustrated that dysregulated miRNAs can participate in the initiation, progression, metastasis, and therapeutic resistance that confer miRNAs to serve as clinical biomarkers and therapeutic targets for CRC. Through binding to the 3′-untranslated region (3′-UTR) of target genes, miRNAs can lead to target mRNA degradation or inhibition at a post-transcriptional level. During the last decade, studies have found numerous miRNAs and their potential targets, but the complex network of miRNA/Targets in CRC remains unclear. In this review, we sought to summarize the complicated roles of the miRNA-target regulation network (Wnt, TGF-β, PI3K-AKT, MAPK, and EMT related pathways) in CRC with up-to-date, high-quality published data. In particular, we aimed to discuss the downstream miRNAs of specific pathways. We hope these data can be a potent supplement for the canonical miRNA-target regulation network.

miR-92a-3p Promoted EMT via Targeting LATS1 in Cervical Cancer Stem Cells

miR-92a-3p (microRNA-92a-3p) has been reported to be dysregulated in several cancers, and as such, it is considered to be a cancer-related microRNA. However, the influence of miR-92a-3p on biological behaviors in cervical cancer (CC) still remains unclear. Quantitative real-time PCR was used to detect miR-92a-3p levels in CC stem cells. Here, Cell Counting Kit-8 (CCK8) assay, Transwell cell invasion assay and flow cytometry assay were used to characterize the effects that miR-92a-3p and large tumor suppressor l (LATS1) had on proliferation, invasion and cell cycle transition. The luciferase reporter gene assay was used to verify the targeting relationship between miR-92a-3p and LATS1. Western Blotting was used to investigate the related signaling pathways and proteins. Data from The Cancer Genome Atlas (TCGA) showed that miR-92a-3p was upregulated in CC tissues and closely associated with overall survival. miR-92a-3p promoted proliferation, invasion and cell cycle transition in CC stem cells. The luciferase reporter assay showed that miR-92a-3p bound to the 3′-untranslated region (3′-UTR) of the LATS1 promoter. LATS1 inhibited proliferation, invasion and cell cycle transition. Results measured by Western Blotting showed that LATS1 downregulated expressions of transcriptional co-activator with PDZ-binding motif (TAZ), vimentin and cyclin E, but upregulated the expression of E-cadherin. Re-expression of LATS1 partly reversed the effects of miR-92a-3p on proliferation, invasion and cell cycle transition, as well as on TAZ, E-cadherin, vimentin, and cyclin E. miR-92a-3p promoted the malignant behavior of CC stem cells by targeting LATS1, which regulated TAZ and E-cadherin.

Antisense locked nucleic acid gapmers to control Candida albicans filamentation

Whereas locked nucleic acid (LNA) has been extensively used to control gene expression, it has never been exploited to control Candida virulence genes. Thus, the main goal of this work was to compare the efficacy of five different LNA-based antisense oligonucleotides (ASO) with respect to the ability to control EFG1 gene expression, to modulate filamentation and to reduce C. albicans virulence. In vitro, all LNA-ASOs were able to significantly reduce C. albicans filamentation and to control EFG1 gene expression. Using the in vivo Galleria mellonella model, important differences among the five LNA-ASOs were revealed in terms of C. albicans virulence reduction. The inclusion of PS-linkage and palmitoyl-2'-amino-LNA chemical modification in these five LNA gapmers proved to be the most promising combination, increasing the survival of G. mellonella by 40%. Our work confirms that LNA-ASOs are useful tools for research and therapeutic development in the candidiasis field.

miR-92a promotes cervical cancer cell proliferation, invasion, and migration by directly targeting PIK3R1

OBJECTIVE

To clarify the role of miR-92a in regulating the malignant progression of cervical cancer and its specific molecular mechanism.

METHODS

qRT-PCR was used to detect the differential expression of miR-92a in cervical cancer and adjacent tissues. The effects of overexpression of miR-92a on the proliferation, migration, and invasion of HeLa and SiHa cells were tested. Luciferase assays and rescue experiments were used to investigate the regulatory mechanism of miR-92a on its downstream gene PIK3R1 and their interaction in the progression of cervical cancer.

RESULTS

miR-92a was significantly up-regulated in cervical cancer tissues. Overexpression of miR-92a significantly increased the ability of cervical cancer cells to proliferate, migrate, and invade. PIK3R1 was identified as a downstream gene of miR-92a. In cervical cancer tissues, PIK3R1 was found to be down-regulated and negatively correlated with the level of miR-92a. Overexpression of PIK3R1 reversed the promotional effect of overexpressed miR-92a on the proliferation, migration, and invasion of cervical cancer.

CONCLUSION

miR-92a is up-regulated in cervical cancer tissues. miR-92a promotes the malignant development of cervical cancer by negatively regulating PIK3R1.

Circulating microRNA-92a-3p in colorectal cancer: a review

Recent studies have found that microRNAs (miRNAs) are present in body fluids, including blood, cerebrospinal fluid, tears, saliva, breast milk, and urine in a stable form, and are called circulating miRNAs. Although their biological roles remain to be determined, circulating miRNAs are considered as mediators of intercellular communication like hormones and cytokines. Because circulating miRNAs can be collected in a non-invasive manner called as "liquid biopsy", they have also been studied as potential biomarkers for early detection, evaluation of therapeutic effects, and prediction of prognosis in various diseases, including cancers. In this review, we focus on the studies on circulating microRNA-92a-3p (miR-92a-3p) in colorectal cancer (CRC), considering their existence form, isolation methods, potential as biomarkers, and roles in CRC development and progression.

Integrated analysis of competing endogenous RNA in esophageal carcinoma

Background

The Competing endogenous RNA (CeRNA) network plays important roles in the development and progression of multiple human cancers. Increasing attention has been paid to CeRNA in esophageal carcinoma (ESCA).

Methods

We explored The Cancer Genome Atlas (TCGA) database and then analyzed the RNAs of 142 samples to obtain long non-coding RNAs (lncRNAs), micro RNAs (miRNAs), and messenger RNAs (mRNAs) with different expression trends alongside the progress of ESCA. A series test of cluster (STC) analysis was carried out to identify a set of unique model expression tendencies. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to validate the function of key genes that were obtained from the STC analysis.

Results

Through our analysis, 272 lncRNAs, 87 miRNAs, and 692 mRNAs showed upward expression or downward expression trends, and these molecules were tightly involved in cell cycle, pathways in cancer, metabolic processes, and protein phosphorylation, among others. Ultimately, we constructed a CeRNA network containing a total of 71 lncRNAs, 56 miRNAs, and 125 mRNAs. The overall survival (OS) was analyzed using univariate Cox regression analysis to clarify the relationship between these key molecules from the CeRNA network and the prognosis of ESCA patients. Through survival analysis, we finally screened out two lncRNAs (DLEU2, RP11-890B15.3), three miRNAs (miR-26b-3p, miR-92a-3p, miR-324-5p), and one mRNA (SIK2) as crucial prognostic factors for ESCA.

Conclusions

The novel CeRNA network that we constructed will provide new novel prognostic biomarkers and therapeutic targets for patients with ESCA.

microRNAs Mediated Regulation of the Ribosomal Proteins and its Consequences on the Global Translation of Proteins

Ribosomal proteins (RPs) are mostly derived from the energy-consuming enzyme families such as ATP-dependent RNA helicases, AAA-ATPases, GTPases and kinases, and are important structural components of the ribosome, which is a supramolecular ribonucleoprotein complex, composed of Ribosomal RNA (rRNA) and RPs, coordinates the translation and synthesis of proteins with the help of transfer RNA (tRNA) and other factors. Not all RPs are indispensable; in other words, the ribosome could be functional and could continue the translation of proteins instead of lacking in some of the RPs. However, the lack of many RPs could result in severe defects in the biogenesis of ribosomes, which could directly influence the overall translation processes and global expression of the proteins leading to the emergence of different diseases including cancer. While microRNAs (miRNAs) are small non-coding RNAs and one of the potent regulators of the post-transcriptional gene expression, miRNAs regulate gene expression by targeting the 3' untranslated region and/or coding region of the messenger RNAs (mRNAs), and by interacting with the 5' untranslated region, and eventually finetune the expression of approximately one-third of all mammalian genes. Herein, we highlighted the significance of miRNAs mediated regulation of RPs coding mRNAs in the global protein translation.

Downregulated microRNA-92a-3p inhibits apoptosis and promotes proliferation of pancreatic acinar cells in acute pancreatitis by enhancing KLF2 expression

Acute pancreatitis (AP) is known worldwide as one of the most common gastrointestinal diseases, prospectively leading to hospitalization coupled with increasing incidence. Several microRNAs (miRNAs) have been reported to be potential biomarkers for pancreatitis. In this study, we verified the hypothesis that miR-92a-3p is implicated in the development of AP by controlling the proliferation and apoptosis of pancreatic acinar cells (PACs) through the modulation of the Kruppel-like factor 2 (KLF2) and inflammatory factors in rats. Initially, we established a rat model of AP and extracted the pancreatic tissues. Then, the positive rate of KLF2 was measured using immunohistochemistry, and the expression of the related genes was determined by rReverse transcription quantitative polymerase chain reaction and Western blot analysis. The cell proliferation and apoptosis were measured by 5-ethynyl-2'-deoxyuridine assay and flow cytometry, and the contents of inflammatory factors were measured using enzyme-linked immunosorbent assay. AP rats presented with increased miR-92a-3p expression as well as decreased KLF2 expression in PACs. The downregulation of miR-92a-3p and overexpression of KLF2 led to decline in expression of nuclear factor-κB (NF-κB), survivin, tumor necrosis factor-α, and Bax as well as extent of NF-κB phosphorylation, contents of inflammatory factors, and apoptosis rate of PACs, but to increased KLF2 and B-cell lymphoma-2 levels and proliferation rate of PACs. Collectively, the data obtained from the present study demonstrated that reduced miR-92a-3p expression may relieve AP through its suppressive effects on cell apoptosis, inflammatory factors, and facilitatory effects on cell proliferation by enhancing KLF2 expression.

Inhibition of miR31 and miR92a as Oncological Biomarkers in RKO Colon Cancer Cells Treated with Kaempferol-3-O-Glycoside Isolated from Black Bean

MicroRNAs (miRNAs) are small molecules of 19-23 nucleotides of RNA that act as regulators of the expression of proteins in eukaryotic cells. Currently, the participation of miRNAs in the development of different types of cancer has been observed. To evaluate the inhibitory effect of kaempferol-3-O-glycoside on the expression of oncological biomarkers, miR31 and miR92a in a colon cancer cell line (RKO) were analyzed. Cells were cultured and treated with 1 mM kaempferol-3-O-glycoside isolated from black bean. Expression levels of miR31 and miR92a were evaluated by real-time PCR using TaqMan probes; in addition, two oncogenes (KRAS and c-MYC) and two tumor suppressors (AMP-activated protein kinase [AMPK] and adenomatous tumors of polyposis coli [APC]) were quantified to validate the biological effects; normalization of expression levels were carried out by 2^-ΔΔCt. Results were analyzed by one-way ANOVA. The expression levels of miR31, miR92a, KRAS oncogene, and the c-MYC transcription factor were subexpressed upon 72 h post-treatment with kaempferol-3-O-glycoside compared with the control without treatment (P < .05); in contrast, the tumor suppressor genes AMPK (∼4.85, P = .005) and APC (∼2.71, P = .066) tumor suppressors genes were overexpressed. Our results showed the inhibitory effect of isolated black bean flavonoid kaempferol-3-O-glycoside on cancer biomarkers: miR31 and miR92a; based on our results, this flavonoid may have interesting nutritional, therapeutic, and/or prophylactic applications to combat colon cancer.

MicroRNAs in cancer cell death pathways: Apoptosis and necroptosis

To protect tissues and the organism from disease, potentially harmful cells are removed through programmed cell death processes, including apoptosis and necroptosis. These types of cell death are critically controlled by microRNAs (miRNAs). MiRNAs are short RNA molecules that target and inhibit expression of many cellular regulators, including those controlling programmed cell death via the intrinsic (Bcl-2 and Mcl-1), extrinsic (TRAIL and Fas), p53-and endoplasmic reticulum (ER) stress-induced apoptotic pathways, as well as the necroptosis cell death pathway. In this review, we discuss the current knowledge of apoptosis and necroptosis pathways and how these are impaired in cancer cells. We focus on how miRNAs disrupt apoptosis and necroptosis, thereby critically contributing to malignancy. Understanding which and how miRNAs and their targets affect cell death pathways could open up novel therapeutic opportunities for cancer patients. Indeed, restoration of pro-apoptotic tumor suppressor miRNAs (apoptomiRs) or inhibition of oncogenic miRNAs (oncomiRs) represent strategies that are currently being trialed or are already applied as miRNA-based cancer therapies. Therefore, better understanding the cancer type-specific expression of apoptomiRs and oncomiRs and their underlying mechanisms in cell death pathways will not only advance our knowledge, but also continue to provide new opportunities to treat cancer.

Faecal microRNAs as a non-invasive tool in the diagnosis of colonic adenomas and colorectal cancer: A meta-analysis

MicroRNAs (miRNAs) are proposed as potential biomarkers for the diagnosis of numerous diseases. Here, we performed a meta-analysis to evaluate the utility of faecal miRNAs as a non-invasive tool in colorectal cancer (CRC) screening. A systematic literature search, according to predetermined criteria, in five databases identified 17 research articles including 6475, 783 and 5569 faecal-based miRNA tests in CRC, adenoma patients and healthy individuals, respectively. Sensitivity, specificity, positive/negative likelihood and diagnostic odds ratios, area under curve (AUC), summary receiver operator characteristic (sROC) curves, association of individual or combinations of miRNAs to cancer stage and location, subgroup, meta-regression and Deeks' funnel plot asymmetry analyses were employed. Pooled miRNAs for CRC had an AUC of 0.811, with a sensitivity of 58.8% (95% confidence interval [CI]: 51.7-65.5%) and specificity of 84.8% (95% CI: 81.1-87.8%), whilst for colonic adenoma, it was 0.747, 57.3% (95% CI: 40.8-72.3%) and 76.1% (95% CI: 66.1-89.4%), respectively. The most reliable individual miRNA was miR-21, with an AUC of 0.843, sensitivity of 59.3% (95% CI: 26.3-85.6%) and specificity of 85.6% (95% CI: 72.2-93.2%). Paired stage analysis showed a better diagnostic accuracy in late stage CRC and sensitivity higher in distal than proximal CRC. In conclusion, faecal miR-21, miR-92a and their combination are promising non-invasive biomarkers for faecal-based CRC screening.

MicroRNA-92a Drives Th1 Responses in the Experimental Autoimmune Encephalomyelitis

Dysregulation of microRNAs (miRNAs) has been linked to the progress of a number of autoimmune diseases including multiple sclerosis (MS), and its animal model, experimental autoimmune encephalomyelitis (EAE). IFN-γ-producing Th1 cells are major players in MS/EAE pathogenesis. It is known that differentiation of T cells towards the Th1 phenotype is influenced by various factors including miRNAs. The miR-92a shows substantial upregulation in MS; however, little is known about its role in the development of autoimmune and inflammatory responses. Herein, we investigated the role of miR-92a in the pathogenesis of MS, focusing on its potential effects on differentiation of Th1 cells. The expression levels of miR-92a were assessed in the spinal cord tissues and splenocytes from mice with EAE using real-time RT-PCR. Next, using transfection with miR-92a mimic sequences, the potential involvement of miR-92a in Th1 polarization was investigated by flow cytometric analysis. Moreover, the expression levels of miR-92a targets were explored in spinal cord tissues of EAE mice. miR-92a expression was enhanced in mouse spinal cord samples at the peak of EAE disease. Overexpression of miR-92a in splenocytes led to increased differentiation of Th1 cells compared with cells transfected with negative control sequences. Enhanced miR-92a expression was accompanied by reduced expression TSC1 or DUSP10, predicted miR-92a targets, in EAE spinal cords. Our data point to a potential role for miR-92a in neuroinflammatory responses in EAE. Our results indicate that miR-92a might affect Th1 differentiation, likely due to downregulation of TSC1 and DUSP10.

Oncogenic and Tumor-Suppressive Roles of MicroRNAs with Special Reference to Apoptosis: Molecular Mechanisms and Therapeutic Potential

MicroRNAs (miRNAs) are the non-coding class of minute RNA molecules that negatively control post-transcriptional regulation of various functional genes. These miRNAs are transcribed from the loci present in the introns of functional or protein-coding genes, exons of non-coding genes, or even in the 3'-untranslated region (3'-UTR). They have potential to modulate the stability or translational efficiency of a variety of target RNA [messenger RNA (mRNA)]. The regulatory function of miRNAs has been elucidated in several pathological conditions, including neurological (Alzheimer's disease and Parkinson's disease) and cardiovascular conditions, along with cancer. Importantly, miRNA identification in cancer progression and invasion has evolved as an incipient era in cancer treatment. Several studies have shown the influence of miRNAs on various cancer processes, including apoptosis, invasion, metastasis and angiogenesis. In particular, apoptosis induction in tumor cells through miRNA has been extensively studied. The biphasic mode (up- and down-regulation) of miRNA expression in apoptosis and other cancer processes has already been determined. The findings of these studies could be utilized to develop potential therapeutic strategies for the management of various cancers. The present review critically describes the oncogenic and tumor suppressor role of miRNAs in apoptosis and other cancer processes, therapy resistance, and use of their presence in the body fluids as biomarkers.

Potential biomarkers and therapeutic targets in cervical cancer: Insights from the meta-analysis of transcriptomics data within network biomedicine perspective

The malignant neoplasm of the cervix, cervical cancer, has effects on the reproductive tract. Although infection with oncogenic human papillomavirus is essential for cervical cancer development, it alone is insufficient to explain the development of cervical cancer. Therefore, other risk factors such as host genetic factors should be identified, and their importance in cervical cancer induction should be determined. Although gene expression profiling studies in the last decade have made significant molecular findings about cervical cancer, adequate screening and effective treatment strategies have yet to be achieved. In the current study, meta-analysis was performed on cervical cancer-associated transcriptome data and reporter biomolecules were identified at RNA (mRNA, miRNA), protein (receptor, transcription factor, etc.), and metabolite levels by the integration of gene expression profiles with genome-scale biomolecular networks. This approach revealed already-known biomarkers, tumor suppressors and oncogenes in cervical cancer as well as various receptors (e.g. ephrin receptors EPHA4, EPHA5, and EPHB2; endothelin receptors EDNRA and EDNRB; nuclear receptors NCOA3, NR2C1, and NR2C2), miRNAs (e.g., miR-192-5p, miR-193b-3p, and miR-215-5p), transcription factors (particularly E2F4, ETS1, and CUTL1), other proteins (e.g., KAT2B, PARP1, CDK1, GSK3B, WNK1, and CRYAB), and metabolites (particularly, arachidonic acids) as novel biomarker candidates and potential therapeutic targets. The differential expression profiles of all reporter biomolecules were cross-validated in independent RNA-Seq and miRNA-Seq datasets, and the prognostic power of several reporter biomolecules, including KAT2B, PCNA, CD86, miR-192-5p and miR-215-5p was also demonstrated. In this study, we reported valuable data for further experimental and clinical efforts, because the proposed biomolecules have significant potential as systems biomarkers for screening or therapeutic purposes in cervical carcinoma.

Prognostic value of miR-17-5p in cancers: a meta-analysis

Background

Studies have shown that miR-17-5p plays an important role in the development of cancer. The aim of this meta-analysis was to quantitatively analyze the association of miR-17-5p with prognosis in various cancers.

Materials and methods

We searched the PubMed, EMBASE, Web of Science, and Cochrane library databases for relevant studies through August 2017. The prognostic data and clinico-pathological features of overall survival (OS) and disease-free survival (DFS) were extracted to investigate the association between miR-17-5p expression and tumor prognosis. In addition, odds ratios (ORs) were used to assess the correlations between miR-17-5p expression and clinicopathological characteristics.

Results

A total of ten studies were incorporated into this systematic review, and we found that high miR-17-5p expression can predict poor OS for malignancies (combined hazard ratio [HR]=1.87; 95% confidence interval [CI], 1.37–2.55; P=0.000) as well as poor DFS (combined HR=1.60; 95% CI, 1.05–2.44; P=0.027). Further subgroup analyses suggested that high miR-17-5p expression was related to poor OS in Asian patients (combined HR=1.92; 95% CI, 1.37–2.71; P=0.000) and the serum/plasma sample source subgroup (combined HR=2.13; 95% CI, 1.36–3.31; P=0.001). The combined OR indicated that the expression of miR-17-5p was associated with lymph node invasion (OR=1.28; 95% CI, 1.05–1.56; P=0.016) and venous invasion (OR=1.92; 95% CI, 1.40–2.63; P=0.000).

Conclusion

Elevated expression of miR-17-5p suggested a poor prognosis in cancer patients and may serve as a new tumor marker to monitor cancer development and progression.

Urinary cell microRNA-based prognostic classifier for non-muscle invasive bladder cancer

Current prognostic tools for non-muscle invasive bladder cancer (NMIBC) do not have enough discriminative capacity to predict the risk of tumour progression. This study aimed to identify urinary cell microRNAs that may be useful as non-invasive predictive biomarkers of tumour progression in NMIBC patients. To this end, 210 urine samples from NMIBC patients were included in the study. RNA was extracted from urinary cells and expression of 8 microRNAs, previously described by our group, was analysed by quantitative PCR. A tumour progression predicting model was developed by Cox regression analysis and validated by bootstrapping. Regression analysis identified miR-140-5p and miR-92a-3p as independent predictors of tumour progression. The risk score derived from the model containing these two microRNAs was able to discriminate between two groups with a highly significant different probability of tumour progression (HR, 5.204; p<0.001) which was maintained when patients were stratified according to tumour risk. The algorithm was also able to identify two groups with different cancer-specific survival (HR, 3.879; p=0.021). Although the data needs to be externally validated, miRNA analysis in urine appears to be a valuable prognostic tool in NMIBC patients.

miR-92a Inhibits Proliferation and Induces Apoptosis by Regulating Methylenetetrahydrofolate Dehydrogenase 2 (MTHFD2) Expression in Acute Myeloid Leukemia

Aberrant expression of microRNA-92a (miR-92a) has been investigated in various cancers. However, the function and mechanism of miR-92a in acute myeloid leukemia (AML) remain to be elucidated. Our data showed that miR-92a was evidently downregulated and methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) was remarkably upregulated in AML cell lines HL-60 and THP-1. Dual luciferase reporter assay revealed that MTHFD2 was a direct target of miR-92a. Gain- and loss-of-function analysis demonstrated that MTHFD2 knockdown or miR-92a overexpression notably inhibited proliferation and promoted apoptosis of AML cell lines. Restoration of MTHFD2 expression reversed proliferation inhibition and apoptosis induction of AML cells triggered by miR-92a. Moreover, an implanted tumor model in mice indicated that miR-92a overexpression dramatically decreased tumor growth and MTHFD2 expression in vivo. Taken together, our results suggest that miR-92a inhibits proliferation and induces apoptosis by directly regulating MTHFD2 expression in AML. miR-92a may act as a tumor suppressor in AML, providing a promising therapeutic target for AML patients.