Roles of miR-182 in sensory organ development and cancer

The TGFβ Induced MicroRNAome of the Trabecular Meshwork

Primary open-angle glaucoma (POAG) is a progressive optic neuropathy with a complex, multifactorial aetiology. Raised intraocular pressure (IOP) is the most important clinically modifiable risk factor for POAG. All current pharmacological agents target aqueous humour dynamics to lower IOP. Newer therapeutic agents are required as some patients with POAG show a limited therapeutic response or develop ocular and systemic side effects to topical medication. Elevated IOP in POAG results from cellular and molecular changes in the trabecular meshwork driven by increased levels of transforming growth factor β (TGFβ) in the anterior segment of the eye. Understanding how TGFβ affects both the structural and functional changes in the outflow pathway and IOP is required to develop new glaucoma therapies that target the molecular pathology in the trabecular meshwork. In this study, we evaluated the effects of TGF-β1 and -β2 treatment on miRNA expression in cultured human primary trabecular meshwork cells. Our findings are presented in terms of specific miRNAs (miRNA-centric), but given miRNAs work in networks to control cellular pathways and processes, a pathway-centric view of miRNA action is also reported. Evaluating TGFβ-responsive miRNA expression in trabecular meshwork cells will further our understanding of the important pathways and changes involved in the pathogenesis of glaucoma and could lead to the development of miRNAs as new therapeutic modalities in glaucoma.

From oncogenes to tumor suppressors: The dual role of ncRNAs in fibrosarcoma

Fibrosarcoma is a challenging cancer originating from fibrous tissues, marked by aggressive growth and limited treatment options. The discovery of non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and small interfering RNAs (siRNAs), has opened new pathways for understanding and treating this malignancy. These ncRNAs play crucial roles in gene regulation, cellular processes, and the tumor microenvironment. This review aims to explore the impact of ncRNAs on fibrosarcoma's pathogenesis, progression, and resistance to treatment, focusing on their mechanistic roles and therapeutic potential. A comprehensive review of literature from databases like PubMed and Google Scholar was conducted, focusing on the dysregulation of ncRNAs in fibrosarcoma, their contribution to tumor growth, metastasis, drug resistance, and their cellular pathway interactions. NcRNAs significantly influence fibrosarcoma, affecting cell proliferation, apoptosis, invasion, and angiogenesis. Their function as oncogenes or tumor suppressors makes them promising biomarkers and therapeutic targets. Understanding their interaction with the tumor microenvironment is essential for developing more effective treatments for fibrosarcoma. Targeting ncRNAs emerges as a promising strategy for fibrosarcoma therapy, offering hope to overcome the shortcomings of existing treatments. Further investigation is needed to clarify specific ncRNAs' roles in fibrosarcoma and to develop ncRNA-based therapies, highlighting the significance of ncRNAs in improving patient outcomes in this challenging cancer.

Transcription Factor EGR1 Facilitates Neovascularization in Mice with Retinopathy of Prematurity by Regulating the miR-182-5p/EFNA5 Axis

Neovascularization is the hallmark of retinopathy of prematurity (ROP). Early growth response 1 (EGR1) has been reported as an angiogenic factor. This study was conducted to probe the regulatory mechanism of EGR1 in neovascularization in ROP model mice. The ROP mouse model was established, followed by determination of EGR1 expression and assessment of neovascularization [vascular endothelial growth factor-A (VEGF-A) and pigment epithelium-derived factor (PEDF)]. Retinal vascular endothelial cells were cultured and treated with hypoxia, followed by the tube formation assay. The state of oxygen induction was assessed by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot assay to determine hypoxia-inducible factor 1-alpha (HIF-1A). The levels of microRNA (miRNA)-182-5p and ephrin-A5 (EFNA5) in tissues and cells were determined by RT-qPCR. Chromatin immunoprecipitation and dual-luciferase assay were used to validate gene interaction. EGR1 and EFNA5 were upregulated in the retina of ROP mice while miR-182-5p was downregulated. EGR1 knockdown decreased VEGF-A and HIF-1A expression and increased PEDF expression in the retina of ROP mice. In vitro, EGR1 knockdown also reduced neovascularization. EGR1 binding to the miR-182-5p promoter inhibited miR-182-5p transcription and further promoted EFNA5 transcription. miR-182-5p downregulation or EFNA5 overexpression averted the inhibition of neovascularization caused by EGR1 downregulation. Overall, EGR1 bound to the miR-182-5p promoter to inhibit miR-182-5p transcription and further promoted EFNA5 transcription, thus promoting retinal neovascularization in ROP mice.

Effect of miR-182-5p on apoptosis in myocardial infarction

Objective

This study aimed to delineate the diagnostic significance of miR-182-5p by investigating its influence on myocardial apoptosis and function, employing both in vivo and in vitro myocardial infarction models.

Methods

A rat myocardial infarction model was established. Myocardial infarction area was detected using the 2,3,5-chlorotriphenyltetrazolium (TTC) method, myocardial enzyme spectrums were measured using enzyme-linked immunosorbent assay (ELISA), myocardial structure was detected by hematoxylin and eosin (HE) staining, myocardial apoptosis was detected using the TUNEL method, and expression levels of miR-182-5p and apoptosis-related molecules were detected using real-time fluorescence quantitative PCR (qPCR) and Western blot. miR-182-5p mimics and inhibitor were transfected into rat H9C2 cardiomyocytes and mouse HL-1 cardiomyocytes to establish a hypoxia model. Cardiomyocyte viability was detected using the CCK-8 method, expression levels of apoptosis-related indicators were detected using Western blot, and caspase-3/7 activity was detected using a caspase-3/7 activity detection kit. AAV9 adeno-associated virus was used to construct an miR-182-5p overexpression virus, which was injected into mice through the tail vein to create a mouse myocardial infarction model. TTC, ELISA, HE staining, echocardiography, real-time fluorescence qPCR, and Western blot methods were used to detect the effects of AAV9-miR-182-5p on myocardial injury, myocardial function, and myocardial apoptosis levels in myocardial infarction.

Results

The rat model displayed reduced miR-182-5p expression concurrent with an increase in apoptosis. The in vitro H9C2 and HL-1 hypoxia models revealed that miR-182-5p augmented the hypoxia-induced decrease in myocardial cell viability, suppressed Bcl-2 expression, and increased Bax, Bnip3, and caspase-3/7 activity levels. The injection of AAV9-miR-182-5p significantly exacerbated myocardial tissue damage, impaired myocardial function, and enhanced apoptosis.

Conclusion

miR-182-5p escalates myocardial injury during myocardial infarction by fostering apoptosis. Interventions that aim to reduce miR-182-5p levels might be crucial in halting the progression of myocardial infarction.

ER Negative Breast Cancer and miRNA: There Is More to Decipher Than What the Pathologist Can See!

Breast cancer (BC), the most prevalent cancer in women, is a heterogenous disease. Despite advancements in BC diagnosis, prognosis, and therapeutics, survival rates have drastically decreased in the metastatic setting. Therefore, BC still remains a medical challenge. The evolution of high-throughput technology has highlighted gaps in the classification system of BCs. Of particular interest is the notorious triple negative BC, which was recounted as being heterogenous itself and it overlaps with distinct subtypes, namely molecular apocrine (MA) and luminal androgen (LAR) BCs. These subtypes are, even today, still misdiagnosed and poorly treated. As such, researchers and clinicians have been looking for ways through which to refine BC classification in order to properly understand the initiation, development, progression, and the responses to the treatment of BCs. One tool is biomarkers and, specifically, microRNA (miRNA), which are highly reported as associated with BC carcinogenesis. In this review, the diverse roles of miRNA in estrogen receptor negative (ER-) and androgen receptor positive (AR+) BC are depicted. While highlighting their oncogenic and tumor suppressor functions in tumor progression, we will discuss their diagnostic, prognostic, and predictive biomarker potentials, as well as their drug sensitivity/resistance activity. The association of several miRNAs in the KEGG-reported pathways that are related to ER-BC carcinogenesis is presented. The identification and verification of accurate miRNA panels is a cornerstone for tackling BC classification setbacks, as is also the deciphering of the carcinogenesis regulators of ER - AR + BC.

A novel microRNA-182/Interleukin-8 regulatory axis controls osteolytic bone metastasis of lung cancer

Bone metastasis is one of the main complications of lung cancer and most important factors that lead to poor life quality and low survival rate in lung cancer patients. However, the regulatory mechanisms underlying lung cancer bone metastasis are still poor understood. Here, we report that microRNA-182 (miR-182) plays a critical role in regulating osteoclastic metastasis of lung cancer cells. We found that miR-182 was significantly upregulated in both bone-metastatic human non-small cell lung cancer (NSCLC) cell line and tumor specimens. We further demonstrated that miR-182 markedly enhanced the ability of NSCLC cells for osteolytic bone metastasis in nude mice. Mechanistically, miR-182 promotes NSCLC cells to secrete Interleukin-8 (IL-8) and in turn facilitates osteoclastogenesis via activating STAT3 signaling in osteoclast progenitor cells. Importantly, systemically delivered IL-8 neutralizing antibody inhibits NSCLC bone metastasis in nude mice. Collectively, our findings identify the miR-182/IL-8/STAT3 axis as a key regulatory pathway in controlling lung cancer cell-induced osteolytic bone metastasis and suggest a promising therapeutic strategy that targets this regulatory axis to interrupt lung cancer bone metastasis.

CircRNA-regulated immune responses of asian honey bee workers to microsporidian infection

Nosema ceranae is a widespread fungal parasite for honey bees, causing bee nosemosis. Based on deep sequencing and bioinformatics, identification of circular RNAs (circRNAs) in Apis cerana workers’ midguts and circRNA-regulated immune response of host to N. ceranae invasion were conducted in this current work, followed by molecular verification of back-splicing sites and expression trends of circRNAs. Here, 10185 and 7405 circRNAs were identified in the midguts of workers at 7 days (AcT1) and 10 days (AcT2) post inoculation days post-inoculation with N. ceranae. PCR amplification result verified the back-splicing sites within three specific circRNAs (novel_circ_005123, novel_circ_007177, and novel_circ_015140) expressed in N. ceranae-inoculated midgut. In combination with transcriptome data from corresponding un-inoculated midguts (AcCK1 and AcCK2), 2266 circRNAs were found to be shared by the aforementioned four groups, whereas the numbers of specific ones were 2618, 1917, 5691, and 3723 respectively. Further, 83 52) differentially expressed circRNAs (DEcircRNAs) were identified in AcCK1 vs. AcT1 (AcCK2 vs. AcT2) comparison group. Source genes of DEcircRNAs in workers’ midgut at seven dpi were involved in two cellular immune-related pathways such as endocytosis and ubiquitin mediated proteolysis. Additionally, competing endogenous RNA (ceRNA) network analysis showed that 23 13) DEcircRNAs in AcCK1 vs. AcT1 (AcCK2 vs. AcT2) comparison group could target 18 14) miRNAs and further link to 1111 (1093) mRNAs. These target mRNAs were annotated to six cellular immunity pathways including endocytosis, lysosome, phagosome, ubiquitin mediated proteolysis, metabolism of xenobiotics by cytochrome P450, and insect hormone biosynthesis. Moreover, 284 164) internal ribosome entry site and 54 26) ORFs were identified from DEcircRNAs in AcCK1 vs. AcT1 (AcCK2 vs. AcT2) comparison group; additionally, ORFs in DEcircRNAs in midgut at seven dpi with N. ceranae were associated with several cellular immune pathways including endocytosis and ubiquitin-mediated proteolysis. Ultimately, RT-qPCR results showed that the expression trends of six DEcircRNAs were consistent with those in transcriptome data. These results demonstrated that N. ceranae altered the expression pattern of circRNAs in A. c. cerana workers’ midguts, and DEcircRNAs were likely to regulate host cellular and humoral immune response to microsporidian infection. Our findings lay a foundation for clarifying the mechanism underlying host immune response to N. ceranae infection and provide a new insight into interaction between Asian honey bee and microsporidian.

FBXW7 and the Hallmarks of Cancer: Underlying Mechanisms and Prospective Strategies

FBXW7, a member of the F-box protein family within the ubiquitin–proteasome system, performs an indispensable role in orchestrating cellular processes through ubiquitination and degradation of its substrates, such as c-MYC, mTOR, MCL-1, Notch, and cyclin E. Mainly functioning as a tumor suppressor, inactivation of FBXW7 induces the aberrations of its downstream pathway, resulting in the occurrence of diseases especially tumorigenesis. Here, we decipher the relationship between FBXW7 and the hallmarks of cancer and discuss the underlying mechanisms. Considering the interplay of cancer hallmarks, we propose several prospective strategies for circumventing the deficits of therapeutic resistance and complete cure of cancer patients.

Prognostic Potential of MicroRNAs in Glioma Patients: A Meta-Analysis

Introduction MicroRNAs are a noncoding RNA involved in affecting several transcription and translation pathways. Their use has been discussed as potential predictors of several tumors. Their use as potential biomarker in glioma patients is still controversial. The purpose of this meta-analysis is to explore the possible role of such microRNAs in glioma patients.

Methods After an extensive literature search done on PubMed and Embase, 20 studies were chosen for our analyses with the 9 discussing 11 tumor promoting microRNAs and 11 studies discussing 11 tumor suppressing microRNAs. The data needed was extracted from these studies including the hazard ratio that was used as the effect size for the purpose of our analysis. The needed analysis was performed using Stata and Excel.

Results The pooled hazard ratio for our analysis with patients having a lower microRNA expression for tumor promoting microRNAs came to be 2.63 (p < 0.001), while the hazard ratio for patients with higher expression of tumor promoting microRNA was 2.47 (p < 0.001) with both results being statistically significant. However, as significant heterogeneity was observed a random effect model for analysis was used. Subgroup analysis was further performed using grade, cutoff value (mean or median), sample type (Serum or Blood), and Karnofsky performance score, all of them showing a high hazard ratio.

Conclusion Our results showed that both tumor inhibitory and promoting microRNA can be used as prognostic tool in glioma patients with a poorer prognosis associated with a lower expression in tumor suppressive and higher expression in tumor promoting microRNA, respectively. However, to support this, future studies on a much larger scale would be needed.

miR-182-5p Regulates Nogo-A Expression and Promotes Neurite Outgrowth of Hippocampal Neurons In Vitro

Nogo-A protein is a key myelin-associated inhibitor of axonal growth, regeneration, and plasticity in the central nervous system (CNS). Regulation of the Nogo-A/NgR1 pathway facilitates functional recovery and neural repair after spinal cord trauma and ischemic stroke. MicroRNAs are described as effective tools for the regulation of important processes in the CNS, such as neuronal differentiation, neuritogenesis, and plasticity. Our results show that miR-182-5p mimic specifically downregulates the expression of the luciferase reporter gene fused to the mouse Nogo-A 3′UTR, and Nogo-A protein expression in Neuro-2a and C6 cells. Finally, we observed that when rat primary hippocampal neurons are co-cultured with C6 cells transfected with miR-182-5p mimic, there is a promotion of the outgrowth of neuronal neurites in length. From all these data, we suggest that miR-182-5p may be a potential therapeutic tool for the promotion of axonal regeneration in different diseases of the CNS.

miR-182 targeting reprograms tumor-associated macrophages and limits breast cancer progression

Breast cancer is a major threat of women’s health worldwide. Nontumor cell components play crucial roles in cancer. Macrophages, the cells of the innate immune system that normally exert antitumor activities, can be educated by tumors to an alternatively activated phenotype that is known to promote tumor progression. Understanding the mechanism of macrophage education by tumor cells will help the design of new therapeutic approaches. We find that breast tumor cells induce the expression of a microRNA, miR-182, in macrophages, and miR-182 promotes macrophage alternative activation to drive tumor development. Importantly, using cationized mannan-modified extracellular vesicles to load miR-182 inhibitors and deliver the inhibitors specifically into macrophages can effectively inhibit alternative activation of macrophages and suppress breast tumor development.

The protumor roles of alternatively activated (M2) tumor-associated macrophages (TAMs) have been well established, and macrophage reprogramming is an important therapeutic goal. However, the mechanisms of TAM polarization remain incompletely understood, and effective strategies for macrophage targeting are lacking. Here, we show that miR-182 in macrophages mediates tumor-induced M2 polarization and can be targeted for therapeutic macrophage reprogramming. Constitutive miR-182 knockout in host mice and conditional knockout in macrophages impair M2-like TAMs and breast tumor development. Targeted depletion of macrophages in mice blocks the effect of miR-182 deficiency in tumor progression while reconstitution of miR-182-expressing macrophages promotes tumor growth. Mechanistically, cancer cells induce miR-182 expression in macrophages by TGFβ signaling, and miR-182 directly suppresses TLR4, leading to NFκb inactivation and M2 polarization of TAMs. Importantly, therapeutic delivery of antagomiR-182 with cationized mannan-modified extracellular vesicles effectively targets macrophages, leading to miR-182 inhibition, macrophage reprogramming, and tumor suppression in multiple breast cancer models of mice. Overall, our findings reveal a crucial TGFβ/miR-182/TLR4 axis for TAM polarization and provide rationale for RNA-based therapeutics of TAM targeting in cancer.

Circular RNA hsa_circ_0001658 regulates apoptosis and autophagy in gastric cancer through microRNA-182/Ras-related protein Rab-10 signaling axis

Gastric cancer (GC) is a tumor with high incidence and lack of early diagnostic markers. The aim of this study was to explore novel regulatory circular RNAs (circRNAs) in GC and their underlying mechanisms. Differentially expressed circRNAs were analyzed using the Gene Expression Omnibus (GEO). mRNA and miRNA expression levels were determined using real-time reverse transcription polymerase chain reaction (RT-qPCR). Protein expression was detected using Western blotting. Cellular functions were evaluated using the cell counting kit-8 (CCK-8) assay and flow cytometry analysis. Immunofluorescence analysis was used to visually identify microtubule-associated protein 1 light chain 3 (LC3) puncta on a per-cell basis. Furthermore, dual-luciferase reporter and RNA pull-down assays were performed to verify the interaction between microRNA (miR)-182 and circ_0001658/Ras-related protein Rab-10 (RAB10). Circ_0001658 was identified to be aberrantly expressed in GC tissues and was demonstrated in GC cell lines (AGS and HGC27) in vitro. MiR-182 bound to circ_0001658 and RAB10. Circ_0001658 and RAB10 were upregulated, whereas miR-182 was suppressed in AGS and HGC27 cells. GC cell viability and autophagy were inhibited and apoptosis was promoted after circ_0001658 knockdown, and the cellular functions were reversed by downregulating miR-182. Moreover, upregulated RAB10 neutralized the effects of miR-182 on cell viability, autophagy, and apoptosis of GC cells. Silencing circ_0001658 restrained cell viability, suppressed autophagy, and promoted apoptosis of GC cells by sponging miR-182 to suppress the expression of RAB10. Therefore, circ_0001658 may be a potential therapeutic target for GC.

Circulating Levels of MicroRNAs Associated With Hypertension: A Cross-Sectional Study in Male and Female South African Participants

MicroRNAs are non-coding, post-transcriptional regulators of gene expression and their dysregulation has been associated with development of various diseases, including hypertension. Consequently, understanding their role in the pathogenesis and progression of disease is essential. Prior research focusing on microRNAs in disease has provided a basis for understanding disease prognosis and offered possible channels for therapeutic interventions. Herein, we aimed to investigate possible differences in the expression profiles of five microRNAs in the blood of participants grouped on the basis of their hypertension status. This was done to elucidate the possible roles played by these microRNAs in the development of hypertension. Using quantitative reverse transcription polymerase chain reaction, we evaluated the expression levels of miR-126-3p, 30a-5p, 182-5p, 30e-3p, and 1299 in the whole blood of 1456 participants, normotensive (n = 573), screen-detected hypertensive (n = 304) and known hypertensive (n = 579). The expression of miR-126-3p and 182-5p was significantly higher in known hypertensives relative to both screen-detected hypertensives and normotensives, and also in screen-detected hypertensives vs normotensives. A significant association between the expression of miR-126-3p, 182-5p, and 30a-5p and known hypertension was also evident. This study demonstrated dysregulated miR-126-3p, 182-5p, and 30a-5p expression in hypertension, highlighting the possible efficacy of these microRNAs as targets for the diagnosis of hypertension as well as the development of microRNA-based therapies.

Role of miR-182/PDCD4 axis in aggressive behavior of prostate cancer in the African Americans

Background

Prostate cancer is one of the most commonly diagnosed cancers among men. African Americans (AA) are at an increased risk of developing prostate cancer compared to European Americans (EA). miRNAs play a critical role in these tumors, leading to tumor progression. In this study, we investigated the role of miR-182 in racial disparity in prostate cancer.

Results

We found significantly increased levels of miR-182 in prostate cancer tissues compared to BPH. Also, miR-182 shows increased expression in AA prostate cancer cell line and tissue samples compared to EA. We performed biochemical recurrence (BCR) - free survival time in AA and EA patients and found that high miR-182 expression had significantly shorter BCR-free survival than patients with low miR-182 expression (P = 0.031). To elucidate the role of miR-182, we knocked down miR-182 in EA (DU-145 and LNCaP) and AA (MDA-PCa-2b) cell lines and found an increase in apoptosis, arrest of the cell cycle, and inhibition of colony formation in the AA cell line to a greater extent than EA cell lines.

Conclusions

Our results showed that PDCD4 is a direct miR-182 target and its inhibition is associated with aggressiveness and high Gleason grade in prostate cancer among AA. These findings show that miR-182 is highly expressed in AA patients and miR-182 may be a target for effective therapy in AA patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08723-6.

Targeting pyruvate dehydrogenase kinase signaling in the development of effective cancer therapy

Pyruvate is irreversibly decarboxylated to acetyl coenzyme A by mitochondrial pyruvate dehydrogenase complex (PDC). Decarboxylation of pyruvate is considered a crucial step in cell metabolism and energetics. The cancer cells prefer aerobic glycolysis rather than mitochondrial oxidation of pyruvate. This attribute of cancer cells allows them to sustain under indefinite proliferation and growth. Pyruvate dehydrogenase kinases (PDKs) play critical roles in many diseases because they regulate PDC activity. Recent findings suggest an altered metabolism of cancer cells is associated with impaired mitochondrial function due to PDC inhibition. PDKs inhibit the PDC activity via phosphorylation of the E1a subunit and subsequently cause a glycolytic shift. Thus, inhibition of PDK is an attractive strategy in anticancer therapy. This review highlights that PDC/PDK axis could be implicated in cancer's therapeutic management by developing potential small-molecule PDK inhibitors. In recent years, a dramatic increase in the targeting of the PDC/PDK axis for cancer treatment gained an attention from the scientific community. We further discuss breakthrough findings in the PDC-PDK axis. In addition, structural features, functional significance, mechanism of activation, involvement in various human pathologies, and expression of different forms of PDKs (PDK1-4) in different types of cancers are discussed in detail. We further emphasized the gene expression profiling of PDKs in cancer patients to prognosis and therapeutic manifestations. Additionally, inhibition of the PDK/PDC axis by small molecule inhibitors and natural compounds at different clinical evaluation stages has also been discussed comprehensively.

Post-transcriptional repression of circadian component CLOCK regulates cancer-stemness in murine breast cancer cells

Disruption of the circadian clock machinery in cancer cells is implicated in tumor malignancy. Studies on cancer therapy reveal the presence of heterogeneous cells, including breast cancer stem-like cells (BCSCs), in breast tumors. BCSCs are often characterized by high aldehyde dehydrogenase (ALDH) activity, associated with the malignancy of cancers. In this study, we demonstrated the negative regulation of ALDH activity by the major circadian component CLOCK in murine breast cancer 4T1 cells. The expression of CLOCK was repressed in high-ALDH-activity 4T1, and enhancement of CLOCK expression abrogated their stemness properties, such as tumorigenicity and invasive potential. Furthermore, reduced expression of CLOCK in high-ALDH-activity 4T1 was post-transcriptionally regulated by microRNA: miR-182. Knockout of miR-182 restored the expression of CLOCK, resulted in preventing tumor growth. Our findings suggest that increased expression of CLOCK in BCSCs by targeting post-transcriptional regulation overcame stemness-related malignancy and may be a novel strategy for breast cancer treatments.

Characterizing RNA stability genome-wide through combined analysis of PRO-seq and RNA-seq data

BACKGROUND

The concentrations of distinct types of RNA in cells result from a dynamic equilibrium between RNA synthesis and decay. Despite the critical importance of RNA decay rates, current approaches for measuring them are generally labor-intensive, limited in sensitivity, and/or disruptive to normal cellular processes. Here, we introduce a simple method for estimating relative RNA half-lives that is based on two standard and widely available high-throughput assays: Precision Run-On sequencing (PRO-seq) and RNA sequencing (RNA-seq).

RESULTS

Our method treats PRO-seq as a measure of transcription rate and RNA-seq as a measure of RNA concentration, and estimates the rate of RNA decay required for a steady-state equilibrium. We show that this approach can be used to assay relative RNA half-lives genome-wide, with good accuracy and sensitivity for both coding and noncoding transcription units. Using a structural equation model (SEM), we test several features of transcription units, nearby DNA sequences, and nearby epigenomic marks for associations with RNA stability after controlling for their effects on transcription. We find that RNA splicing-related features are positively correlated with RNA stability, whereas features related to miRNA binding and DNA methylation are negatively correlated with RNA stability. Furthermore, we find that a measure based on U1 binding and polyadenylation sites distinguishes between unstable noncoding and stable coding transcripts but is not predictive of relative stability within the mRNA or lincRNA classes. We also identify several histone modifications that are associated with RNA stability.

CONCLUSION

We introduce an approach for estimating the relative half-lives of individual RNAs. Together, our estimation method and systematic analysis shed light on the pervasive impacts of RNA stability on cellular RNA concentrations.

RNA in cancer

While the processing of mRNA is essential for gene expression, recent findings have highlighted that RNA processing is systematically altered in cancer. Mutations in RNA splicing factor genes and the shortening of 3' untranslated regions are widely observed. Moreover, evidence is accumulating that other types of RNAs, including circular RNAs, can contribute to tumorigenesis. In this Review, we highlight how altered processing or activity of coding and non-coding RNAs contributes to cancer. We introduce the regulation of gene expression by coding and non-coding RNA and discuss both established roles (microRNAs and long non-coding RNAs) and emerging roles (selective mRNA processing and circular RNAs) for RNAs, highlighting the potential mechanisms by which these RNA subtypes contribute to cancer. The widespread alteration of coding and non-coding RNA demonstrates that altered RNA biogenesis contributes to multiple hallmarks of cancer.

PIWIL-2 and piRNAs are regularly expressed in epithelia of the skin and their expression is related to differentiation

PIWI proteins play multiple roles in germline stem cell maintenance and self-renewal. PIWI-interacting RNAs (piRNAs) associate with PIWI proteins, form effector complexes and maintain genome integrity and function in the regulation of gene expression by epigenetic modifications. Both are involved in cancer development. In this study, we investigated the expression of PIWIL-2 and piRNAs in normal human skin and epithelial tumors and its regulation during keratinocyte (KC) differentiation. Immunohistochemistry showed that PIWIL-2 was regularly expressed in the epidermis and adnexal tissue with strongest expression in sebaceous glands. Cell culture studies revealed an association of PIWIL-2 expression with the state of differentiated KC. In contrast, the PIWIL-2 expression pattern did not correlate with stem cell compartments or malignancy. piRNAs were consistently detected in KC in vitro by next-generation sequencing and the expression levels of numerous piRNAs were regulated during KC differentiation. Epidermal piRNAs were predominantly derived from processed snoRNAs (C/D-box snoRNAs), tRNAs and protein coding genes. Our data indicate that components of the PIWIL-2-piRNA pathway are present in epithelial cells of the skin and are regulated in the context of KC differentiation, suggesting a role of somatic gene regulation. However, putative roles in the maintenance of stem cell compartments or the development of malignancy in the skin were not supported by this study.

MicroRNA-182 supplies negative feedback regulation to ameliorate lipopolysaccharide-induced ALI in mice by targeting TLR4

Acute lung injury (ALI), characterized by increased excessive pulmonary inflammation, is a pervasive inflammatory disease with clinically high incidence. MicroRNA (miRNAs) have been associated with the progression of multiple diseases and are regarded as novel regulators of inflammation. However, it remains largely unknown whether the miRNAs-mediated regulatory mechanism has an effect on lipopolysaccharide (LPS)-induced inflammation in ALI. We discovered that miR-182 distinctly lessened expression in the lung tissue of mice with ALI and macrophages stimulated by LPS. We also found that overexpression of miR-182 significantly cut down the secretion of inflammatory cytokines, while this change was reversed by inhibition of miR-182. In addition, miR-182 suppressed the activation of NF-κB by targeting TLR4 expression. And it was confirmed that miR-182 directly regulated TLR4 expression at the posttranscriptional level by binding to the 3'-UTR of TLR4. Together, these data suggested that inhibition of TLR4 expression assuaged LPS-stimulated inflammation through negative feedback regulation of miR-182.

A genetic variant in the flanking region of miR-182 could decrease the susceptibility to the breast cancer risk in the iranian population

Breast cancer is one of the most malignant tumors in the world. It is, in fact, the second leading cause of cancer death in women. Recent research has identified the role of miR-182 in this disease as an oncogene agent. In this study, the association of rs4541843 in the flanking region of the miR-182 sequence with the susceptibility to breast cancer risk has been studied in the Iranian population. By using the PCR_RFLP, the genotype rs4541843 was determined in 161 patients and 164 control subjects. The genotypes of the individuals were analyzed statistically to find the association between rs4541843 and the breast cancer incidence and its pathological characteristics. The results revealed that due to the dominance of the G allele, the frequency of GG + AG genotypes, as compared with AA, had a significant correlation with the incidence of this disease in controls and cases (P = 0.022; OR = 0.523). Moreover, the genotypes AG and AA could significantly decrease the susceptibility to the breast cancer risk; also in the presence of the A allele (OR, 0.565; P = 0.015), the incidence of the disease could be decreased. Our results indicated that this SNP was associated with the breast cancer risk of the Iranian population. We suppose that rs4541843 may influence the processing of the mature miRNA by affecting the cleavage of Drosha. Therefore, this SNP can be considered as a candidate genetic marker for the susceptibility to breast cancer in the Iranian women.

MiR-182 promotes glioma progression by targeting FBXW7

OBJECTIVE

MicroRNAs (miRNAs) are widely considered to play an important role in the tumor progression. In this study, we aimed to investigate the potential biological effects of miR-182 and its target FBXW7 on glioma development.

METHODS

Expression data of glioma were procured from TCGA database. Differential analysis was performed to identify the potential differentially expressed miRNA (DEmiRNA), and bioinformatics databases were utilized for target genes prediction. qRT-PCR was conducted to detect miR-182 and western blot was performed to test FBXW7 in protein level. Then the cells were processed for proliferation determination by CCK-8, migration test through wound healing assay, invasion detection via Transwell and apoptosis measurement by flow cytometry. In addition, dual-luciferase reporter gene assay was carried out for evaluation of the targeted relationship between the miR-182 and FBXW7.

RESULTS

MiR-182 was found to be up-regulated in glioma cells while FBXW7 was down-regulated. Besides, miR-182 was predicted to targeted bind with FBXW7 on 3'UTR via bioinformatics methods, and their targeted relationship was further validated by dual-luciferase assay. MiR-182 mimic could significantly promote cell proliferation, migration, invasion and inhibit cell apoptosis, while miR-182 inhibitor had the negative effect. Moreover, FBXW7 knockdown could reverse the inhibitory effect of miR-182 inhibitor on glioma cells.

CONCLUSION

MiR-182 promotes cell proliferation, migration, invasion and inhibits cell apoptosis in glioma by targeting FBXW7.

MiR-182-5p and its target HOXA9 in non-small cell lung cancer: a clinical and in-silico exploration with the combination of RT-qPCR, miRNA-seq and miRNA-chip

BACKGROUND

MiR-182-5p, a cancer-related microRNA (miRNA), modulates tumorigenesis and patient outcomes in various human malignances. This study interroted the clinicopathological significance and molecular mechanisms of miR-182-5p in non-small cell lung cancer (NSCLC).

METHODS

The clinical significance of miR-182-5p in NSCLC subtypes was determined based on an analysis of 124 samples (lung adenocarcinomas [LUADs], n = 101; lung squamous cell carcinomas [LUSCs], n = 23) obtained from NSCLC patients and paired noncancer tissues and an analysis of data obtained from public miRNA-seq database, miRNA-chip database, and the scientific literature. The NSCLC samples (n = 124) were analyzed using the real-time quantitative polymerase chain reaction (RT-qPCR). Potential targets of miR-182-5p were identified using lists generated by miRWalk v.2.0, a comprehensive atlas of predicted and validated targets of miRNA-target interactions. Molecular events of miR-182-5p in NSCLC were unveiled based on a functional analysis of candidate targets. The association of miR-182-5p with one of the candidate target genes, homeobox A9 (HOXA9), was validated using in-house RT-qPCR and dual-luciferase reporter assays.

RESULTS

The results of the in-house RT-qPCR assays analysis of data obtained from public miRNA-seq databases, miRNA-chip databases, and the scientific literature all supported upregulation of the expression level of miR-182-5p level in NSCLC. Moreover, the in-house RT-qPCR data supported the influence of upregulated miR-182-5p on malignant progression of NSCLC. In total, 774 prospective targets of miR-182-5p were identified. These targets were mainly clustered in pathways associated with biological processes, such as axonogenesis, axonal development, and Ras protein signal transduction, as well as pathways involved in axonal guidance, melanogenesis, and longevity regulation, in multiple species. Correlation analysis of the in-house RT-qPCR data and dual-luciferase reporter assays confirmed that HOXA9 was a direct target of miR-182-5p in NSCLC.

CONCLUSIONS

The miR-182-5p expression level was upregulated in NSCLC tissues. MiR-182-5p may exert oncogenic influence on NSCLC through regulating target genes such as HOXA9.

DNA methylation directs microRNA biogenesis in mammalian cells

MicroRNA (miRNA) biogenesis initiates co-transcriptionally, but how the Microprocessor machinery pinpoints the locations of short precursor miRNA sequences within long flanking regions of the transcript is not known. Here we show that miRNA biogenesis depends on DNA methylation. When the regions flanking the miRNA coding sequence are highly methylated, the miRNAs are more highly expressed, have greater sequence conservation, and are more likely to drive cancer-related phenotypes than miRNAs encoded by unmethylated loci. We show that the removal of DNA methylation from miRNA loci leads to their downregulation. Further, we found that MeCP2 binding to methylated miRNA loci halts RNA polymerase II elongation, leading to enhanced processing of the primary miRNA by Drosha. Taken together, our data reveal that DNA methylation directly affects miRNA biogenesis.

Silencing of miR-182 is associated with modulation of tumorigenesis through apoptosis induction in an experimental model of colorectal cancer

BACKGROUND

miR-182-5p (miR-182) is an oncogenic microRNA (miRNA) found in different tumor types and one of the most up-regulated miRNA in colorectal cancer (CRC). Although this microRNA is expressed in the early steps of tumor development, its role in driving tumorigenesis is unclear.

METHODS

The effects of miR-182 silencing on transcriptomic profile were investigated using two CRC cell lines characterized by different in vivo biological behavior, the MICOL-14^h-tert cell line (dormant upon transfer into immunodeficient hosts) and its tumorigenic variant, MICOL-14^tum. Apoptosis was studied by annexin/PI staining and cleaved Caspase-3/PARP analysis. The effect of miR-182 silencing on the tumorigenic potential was addressed in a xenogeneic model of MICOL-14^tum transplant.

RESULTS

Endogenous miR-182 expression was higher in MICOL-14^tum than in MICOL-14^h-tert cells. Interestingly, miR-182 silencing had a strong impact on gene expression profile, and the positive regulation of apoptotic process was one of the most affected pathways. Accordingly, annexin/PI staining and caspase-3/PARP activation demonstrated that miR-182 treatment significantly increased apoptosis, with a prominent effect in MICOL-14^tum cells. Moreover, a significant modulation of the cell cycle profile was exerted by anti-miR-182 treatment only in MICOL-14^tum cells, where a significant increase in the fraction of cells in G0/G1 phases was observed. Accordingly, a significant growth reduction and a less aggressive histological aspect were observed in tumor masses generated by in vivo transfer of anti-miR-182-treated MICOL-14^tum cells into immunodeficient hosts.

CONCLUSIONS

Altogether, these data indicate that increased miR-182 expression may promote cell proliferation, suppress the apoptotic pathway and ultimately confer aggressive traits on CRC cells.

MicroRNA heterogeneity in melanoma progression

The altered expression of miRNAs has been linked with neocarcinogenesis or the development of human malignancies including melanoma. Of significance, multiple clinical studies have documented that distinct sets of microRNAs (miRNAs) could be utilized as prognostic biomarkers for cancer development or predict the outcomes of treatment responses. To that end, an in-depth validation of such differentially expressed miRNAs is necessary in diverse settings of cancer patients in order to devise novel approaches to control tumor growth and/or enhance the efficacy of clinically-relevant therapeutic options. Moreover, considering the heterogeneity and sophisticated regulation of miRNAs, the precise delineation of their cellular targets could also be explored to design personalized medicine. Given the significance of miRNAs in regulating several key cellular processes of tumor cells including cell cycle progression and apoptosis, we review the findings of such miRNAs implicated in melanoma tumorigenesis. Understanding the novel mechanistic insights of such miRNAs will be useful for developing diagnostic or prognostic biomarkers or devising future therapeutic intervention for malignant melanoma.

Silibinin encapsulation in polymersome: A promising anticancer nanoparticle for inducing apoptosis and decreasing the expression level of miR-125b/miR-182 in human breast cancer cells

Silibinin, a polyphenolic flavonolignan, is well-known as a safe therapeutic drug without any side effects in the treatment of many malignancies especially cancerous cells. In this study, to overcome problems such as low solubility of silibinin and to enhance its delivery to cancerous cells, we encapsulated silibinin in polymersome nanoparticles. Physicochemical measurements such as dynamic light scattering, transmission electron microscopy, scanning electron microscopy, and atomic force microscopy confirmed the proper encapsulation of silibinin in nanoparticles. Furthermore, antiproliferative and apoptotic activities of silibinin encapsulated in polymersome nanoparticles (SPNs) on MDA-MB-231 breast cancer cell line were validated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Annexin V/Propidium Iodide measurement, and cell cycle analysis. In addition, quantitative reverse transcription polymerase chain reaction analysis confirmed that SPNs can repress oncogenic microRNAs (miRNAs) such as miR-125b and miR-182, as well as antiapoptotic genes such as Bcl2. SPNs can also induce overexpression of proapoptotic target genes such as P53, CASP9, and BAX directly and/or indirectly (through regulation of miRNAs). Our results suggested that polymersomes can be used as stable carriers in nano-dimensions and SPNs can be considered as a promising pharmacological agent for cancer therapy.

miR-182 regulates trastuzumab resistance by targeting MET in breast cancer cells

It has been found that microRNAs (miRNAs) play a key role in drug resistance. The purpose of the current study was to investigate the function of miR-182 in trastuzumab resistance in breast cancer cells. The results showed that both breast cancer SKBR3 trastuzumab-resistant cells (SKBR3/TR) and BT474 trastuzumab-resistant cells (BT474/TR) were associated with miR-182 downregulation compared with their parental cells. Ectopic expression of the miR-182 mimic inhibited trastuzumab resistance, decreasing the invasion and migration of these trastuzumab-resistant cells. However, the miR-182 inhibitor increased trastuzumab resistance, cell invasion, and migration in the parental cells. In addition, MET is a directly targeted gene of miR-182 in breast cancer cells. MET knockdown showed an inhibitory effect of trastuzumab resistance on trastuzumab-resistant cells. In contrast, MET overexpression in SKBR3 cells produced an effect that promotes resistance to trastuzumab. Moreover, we revealed that overexpression of miR-182 reduced trastuzumab resistance in trastuzumab-resistant cells due in part to MET/PI3K/AKT/mTOR signaling pathway inactivation. Furthermore, miR-182 could also sensitize SKBR3/TR cells to trastuzumab in vivo. In conclusion, our results suggest that the activation of miR-182 or inactivation of its target gene pathway could be used as a new method to reverse trastuzumab resistance in breast cancer.

The role of miR-183 cluster in immunity

MicroRNAs (miRNAs) are essential factors of an extensively conserved post-transcriptional process to regulate gene expression. MiRNAs play a pivotal role in immunity, including controlling the differentiation of various immune cells as well as their immunological functions. The miR-183 cluster, which is comprised of miR-183, -96 and -182, is a miRNA family with sequence homology. These miRNAs are usually transcribed together as a polycistronic miRNA cluster during development and are required for maturation of sensory organs. In comparison to defined sensory-specific role of these miRNAs in normal development, they are frequently over-expressed in several non-sensory diseases, including autoimmune diseases and cancers. Because individual miRNAs of miR-183 cluster have both common and unique targets within functionally interrelated pathways, they can show cooperative or opposing effects on biological processes, implying the complexity of this miR cluster-mediated gene regulation. Therefore, a better understanding of the molecular regulation of miR-183 cluster expression and its downstream networks is important for the therapeutic applications. In this review, we will discuss the characteristics of miR-183 cluster and a wide variety of evidence on its function in immune system. Newer knowledge summarized here will help readers understand the versatile role of miR-183 cluster in this field.

Deep sequencing and miRNA profiles in alcohol-induced neuroinflammation and the TLR4 response in mice cerebral cortex

Alcohol abuse can induce brain injury and neurodegeneration, and recent evidence shows the participation of immune receptors toll-like in the neuroinflammation and brain damage. We evaluated the role of miRNAs as potential modulators of the neuroinflammation associated with alcohol abuse and the influence of the TLR4 response. Using mice cerebral cortex and next-generation sequencing (NGS), we identified miRNAs that were differentially expressed in the chronic alcohol-treated versus untreated WT or TLR4-KO mice. We observed a differentially expression of miR-183 Cluster (C) (miR-96/-182/-183), miR-200a and miR-200b, which were down-regulated, while mirR-125b was up-regulated in alcohol-treated WT versus (vs.) untreated mice. These miRNAs modulate targets genes related to the voltage-gated sodium channel, neuron hyperexcitability (Nav1.3, Trpv1, Smad3 and PP1-γ), as well as genes associated with innate immune TLR4 signaling response (Il1r1, Mapk14, Sirt1, Lrp6 and Bdnf). Functional enrichment of the miR-183C and miR-200a/b family target genes, revealed neuroinflammatory pathways networks involved in TLR4 signaling and alcohol abuse. The changes in the neuroinflammatory targets genes associated with alcohol abuse were mostly abolished in the TLR4-KO mice. Our results show the relationship between alcohol intake and miRNAs expression and open up new therapeutically targets to prevent deleterious effects of alcohol on the brain.

Reprogramming Cells for Synergistic Combination Therapy with Nanotherapeutics against Uveal Melanoma

Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults and around half of the patients develop metastasis and die shortly after because of the lack of effective therapies for metastatic UM. Consequently, new therapeutic approaches to this disease are welcome. In this regard, microRNAs have been shown to have a key role in neoplasia progression and have the potential to be used as therapeutic tools. In addition, in different cancers including UM, a particular microRNA signature appears that is different from healthy cells. Thus, restoring the regular levels of microRNAs could restore the normal behavior of cells. In this study, four microRNAs downregulated in UM have been chosen to reprogram cancer cells, to promote cell death or increase their sensitivity to the chemotherapeutic SN38. Furthermore, to improve the internalization, stability and/or solubility of the therapeutic molecules employed in this approach, gold nanoparticles (AuNPs) were used as carriers. Remarkably, this study found a synergistic effect when the four oligonucleotides were employed and when the chemotherapeutic drug was added.

The Network of Non-coding RNAs in Cancer Drug Resistance

Non-coding RNAs (ncRNAs) have been implicated in most cellular functions. The disruption of their function through somatic mutations, genomic imprinting, transcriptional and post-transcriptional regulation, plays an ever-increasing role in cancer development. ncRNAs, including notorious microRNAs, have been thus proposed to function as tumor suppressors or oncogenes, often in a context-dependent fashion. In parallel, ncRNAs with altered expression in cancer have been reported to exert a key role in determining drug sensitivity or restoring drug responsiveness in resistant cells. Acquisition of resistance to anti-cancer drugs is a major hindrance to effective chemotherapy and is one of the most important causes of relapse and mortality in cancer patients. For these reasons, non-coding RNAs have become recent focuses as prognostic agents and modifiers of chemo-sensitivity. This review starts with a brief outline of the role of most studied non-coding RNAs in cancer and then highlights the modulation of cancer drug resistance via known ncRNAs based mechanisms. We identified from literature 388 ncRNA-drugs interactions and analyzed them using an unsupervised approach. Essentially, we performed a network analysis of the non-coding RNAs with direct relations with cancer drugs. Within such a machine-learning framework we detected the most representative ncRNAs-drug associations and groups. We finally discussed the higher integration of the drug-ncRNA clusters with the goal of disentangling effectors from downstream effects and further clarify the involvement of ncRNAs in the cellular mechanisms underlying resistance to cancer treatments.

Isoliquiritigenin suppresses human melanoma growth by targeting miR-301b/LRIG1 signaling

BACKGROUND

Isoliquiritigenin (ISL), a natural flavonoid isolated from the root of licorice (Glycyrrhiza uralensis), has shown various pharmacological properties including anti-oxidant, anti-inflammatory and anti-cancer activities. MicroRNAs (miRNAs), a class of small non-coding RNAs, have been reported as post-transcriptional regulators with altered expression levels in melanoma. This study aims to investigate the anti-melanoma effect of ISL and its potential mechanism.

METHODS

We investigated the effect of ISL on the proliferation and apoptosis of melanoma cell lines with functional assays, such as CCK-8 assay, colony formation assay and flow cytometry. The protein level of apoptosis related genes were measured by western blotting. High-throughput genome sequencing was used for screening differentially expressed miRNAs of melanoma cell lines after the treatment of ISL. We performed functional assays to determine the oncogenic role of miR-301b, the most differentially expressed miRNA, and its target gene leucine rich repeats and immunoglobulin like domains 1 (LRIG1), confirmed by bioinformatic analysis, luciferase reporter assay, western blotting and immunohistochemical assay in melanoma. Immunocompromised mouse models were used to determine the role of miR-301b and its target gene in melanoma tumorigenesis in vivo. The relationship between miR-301b and LRIG1 was further verified in GEO data set and tissue specimens.

RESULTS

Functional assays indicated that ISL exerted significant growth inhibition and apoptosis induction on melanoma cells. MiR-301b is the most differentially expressed miRNA after the treatment of ISL and significantly downregulated. The suppressive effect of ISL on cell growth is reversed by ectopic expression of miR-301b. Intratumorally administration of miR-301b angomir enhances the inhibitory effect of ISL on tumor growth in vivo. Bioinformatic analysis showed that miR-301b may target LRIG1, miR-301b suppresses the luciferase activity of reporter constructs containing 3'UTR of LRIG1 as well as the expression level of LRIG1. And the anti-cancer effect of ISL is mitigated when LRIG1 is silenced in vivo and in vitro. Analysis of the melanoma samples obtained from patients shows that LRIG1 is negatively correlated with miR-301b.

CONCLUSIONS

ISL may inhibit the proliferation of melanoma cells by suppressing miR-301b and inducing its target LRIG1.

MicroRNAs in cutaneous melanoma: Role as diagnostic and prognostic biomarkers

Melanoma is the leading cause of skin cancer deaths in the United States, and its incidence has been rising steadily for the past 30 years (Aftab, Dinger, & Perera, 2014). A more complete understanding of the molecular mechanisms that drive melanomagenesis is crucial to improve diagnosis, prognostication, and treatment of this disease. Given that melanoma survival rates are better when the disease is detected early, precise diagnostic tests for early melanoma detection would be extremely useful. In addition, as survival rates decrease drastically when the disease becomes metastatic, improved tools to more precisely identify high-risk patients as well as to predict treatment response are necessary. The role of microRNAs (miRNAs) in melanoma biology could be the key. miRNA expression profiling has identified several miRNAs that play a crucial role in melanoma cell proliferation, migration, and invasion, as well as miRNAs involved in apoptosis and in the immune response. Here we review the most current data on the miRNAs involved in melanoma as well as their potential roles as diagnostic and prognostic biomarkers of this disease.

miR-182 enhances acute kidney injury by promoting apoptosis involving the targeting and regulation of TCF7L2/Wnt/β-catenins pathway

Acute kidney injury (AKI) is a sudden decay in renal function leading to increasing morbidity and mortality. miR-182 has been reported to be actively involved in kidney diseases. However, the function and molecular mechanism of miR-182 in AKI still need to be elucidated. The levels of serum creatinine (SCr), blood urea nitrogen (BUN), and urine Kim-1 in I/R-induced rat AKI model were detected by a Beckman Autoanalyzer. miR-182 and transcription factor 7-like-2 (TCF7L2) mRNA expression were measured by qRT-PCR. Flow cytometry and caspase-3 colorimetry analysis were performed to determine NRK-52E cell apoptosis. Bioinformatics and dual-luciferase reporter were used to identify the interaction between miR-182 and TCF7L2. miR-182 expression was increased in both I/R-induced rat models and hypoxia-treated NRK-52E cells, and miR-182 overexpression stimulated the apoptosis of hypoxia-induced NRK-52E cells. Dual-luciferase analysis disclosed that TCF7L2 was a target of miR-182. TCF7L2 suppressed hypoxia-induced apoptosis in NRK-52E cells, and the inhibitory effect of TCF7L2 on cell apoptosis could be reversed with miR-182 restoration. Moreover, the activity of Wnt/β-catenin signaling pathway was promoted following overexpression of TCF7L2 in NRK-52E cells with hypoxia treatment, and this effect was greatly attenuated by the increased miR-182 expression. Finally, in vivo experiment also validated the alleviation of miR-182 inhibitor on I/R-induced kidney injury and apoptosis via regulating TCF7L2/ Wnt/β-catenin pathway. miR-182 exacerbated AKI involving the targeting and regulation of TCF7L2/Wnt/β-catenin signaling, unveiling a novel regulatory pathway in ischemia-reperfusion injury and elucidating a potential biomarker for AKI treatment.

MiR-182 promotes cell proliferation by suppressing FBXW7 and FBXW11 in non-small cell lung cancer

OBJECTIVE

MicroRNAs have been found to be deregulated in lung cancers, which play crucial roles in tumorigenesis and progression. FBXW7 and FBXW11, two important F-box proteins of the ubiquitin-proteasome system (UPS), can target multiple substrates for degradation, in order to regulate cell proliferation and survival in cancers. In the present study, we aimed to explore the potential role and regulating mechanism of miR-182 in non-small cell lung cancer (NSCLC).

METHODS

MiRNA expression was evaluated by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). FBXW7, FBXW11, c-Jun, c-Myc and cyclin D protein levels were detected by western blot. Cell growth was determined using cell counting kit (CCK)-8 reagent and colony formation experiment. Then, cell apoptosis and the cell cycle were analyzed on flow cytometry. The target binding activity of miR-182 with FBXW7 or FBXW11 was evaluated through the Dual-Luciferase Reporter Assay System.

RESULTS

It was confirmed that miR-182 was significantly upregulated in tumor tissues, compared with adjacent normal tissues, and this was inversely correlated to the protein levels of FBXW7 and FBXW11. The overexpression of miR-182 in NSCLC cells dramatically promoted cell growth, colony formation capacity and cell cycle progression, and inhibited apoptosis in NSCLC cells. In contrast, the downregulation of miR-182 significantly alleviated these properties in vitro. Furthermore, we demonstrated that miR-182 exerted an oncogenic role in NSCLC by directly targeting FBXW7 and FBXW11.

CONCLUSION

These results bring new insights into the oncogenic role of miR-182 in NSCLC, indicating that miR-182 might be a novel biomarker for the diagnosis and prognosis of NSCLC.

Biosafety and bioefficacy assessment of human mesenchymal stem cells: what do we know so far?

An outstanding amount of resources has been used in research on manipulation of human stem cells, especially mesenchymal stem cells (MSCs), for various clinical applications. However, human MSCs have not been fully utilized in clinical applications due to restrictions with regard to their certain biosafety and bioefficacy concerns, for example, genetic abnormality, tumor formation, induction of host immune response and failure of homing and engraftment. This review summarizes the biosafety and bioefficacy assessment of human MSCs in terms of genetic stability, tumorigenicity, immunogenicity, homing and engraftment. The strategies used to reduce the biosafety concerns and improve the bioefficacy of human MSCs are highlighted. In addition, the approaches that can be implemented to improve their biosafety and bioefficacy assessment are briefly discussed.

Krüppel-like factor 4 (KLF4) regulates the miR-183~96~182 cluster under physiologic and pathologic conditions

MicroRNAs (miRNAs) are a class of endogenous non-coding small RNAs that post-transcriptionally control the translation and stability of target mRNAs in a sequence-dependent manner. MiRNAs are essential for key cellular processes including proliferation, differentiation, cell death and metabolism, among others. Consequently, alterations of miRNA expression contribute to developmental defects and a myriad of diseases.The expression of miRNAs can be altered by several mechanisms including gene copy number alterations, aberrant DNA methylation, defects of the miRNA processing machinery or unscheduled expression of transcription factors. In this work, we sought to analyze the regulation of the miR-182 cluster, located at the 7q32 locus, which encodes three different miRNAs that are abundantly expressed in human embryonic stem cells and de-regulated in cancer. We have found that the Krüppel-like factor 4 (KLF4) directly regulates miR-182 cluster expression in human embryonic stem cells (hESCs) and in melanoma tumors, in which the miR-182 cluster is highly expressed and has a pro-metastatic role. Furthermore, higher KLF4 expression was found to be associated with metastatic progression and poor patient outcome. Loss of function experiments revealed that KLF4 is required for melanoma cell maintenance. These findings provide new insights into the regulation of the miR-182 cluster expression and new opportunities for therapeutic intervention in tumors in which the KLF4-miR-182 cluster axis is deregulated.

Protection of macrophages from intracellular pathogens by miR-182-5p mimic-a gene expression meta-analysis approach

The goals of this study were to (a) define which host genes are of particular importance during the interactions between macrophages and intracellular pathogens, and (b) use this knowledge to gain fresh, experimental understanding of how macrophage activities may be manipulated during host defense. We designed an in silico method for meta-analysis of microarray gene expression data, and used this to combine data from 16 different studies of cells in the monocyte-macrophage lineage infected with seven different pathogens. Three thousand four hundred ninety-eight genes were identified, which we call the macrophage intracellular pathogen response (macIPR) gene set. As expected, the macIPR gene set showed a strong bias toward genes previously associated with the immune response. Predicted target sites for miR-182-5p (miR-182) were strongly over-represented among macIPR genes, indicating an unexpected role for miR-182-regulatable genes during intracellular pathogenesis. We therefore transfected primary human alveolar macrophage-like monocyte-derived macrophages from multiple different donors with synthetic miR-182, and found that miR-182 overexpression (a) increases proinflammatory gene induction during infection with Francisella tularensis live vaccine strain (LVS), (b) primes macrophages for increased autophagy, and (c) enhances macrophage control of both gram negative F. tularensisLVS and gram positive Bacillus anthracisANR-1 spores. These data therefore suggest a new application for miR-182 in promoting resistance to intracellular pathogens.

miR-182 Regulates Slit2-Mediated Axon Guidance by Modulating the Local Translation of a Specific mRNA

During brain wiring, cue-induced axon behaviors such as directional steering and branching are aided by localized mRNA translation. Different guidance cues elicit translation of subsets of mRNAs that differentially regulate the cytoskeleton, yet little is understood about how specific mRNAs are selected for translation. MicroRNAs (miRNAs) are critical translational regulators that act through a sequence-specific mechanism. Here, we investigate the local role of miRNAs in mRNA-specific translation during pathfinding of Xenopus laevis retinal ganglion cell (RGC) axons. Among a rich repertoire of axonal miRNAs, miR-182 is identified as the most abundant. Loss of miR-182 causes RGC axon targeting defects in vivo and impairs Slit2-induced growth cone (GC) repulsion. We find that miR-182 targets cofilin-1 mRNA, silencing its translation, and Slit2 rapidly relieves the repression without causing miR-182 degradation. Our data support a model whereby miR-182 reversibly gates the selection of transcripts for fast translation depending on the extrinsic cue.

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Small RNA-seq analysis reveals that miR-182 is the most abundant miRNA in RGC axons

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miR-182 regulates Slit2-mediated axon guidance of RGCs in vitro and in vivo

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miR-182 silences cofilin-1 local protein synthesis in growth cones

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Slit2 rapidly lifts miR-182-mediated repression of cofilin-1 without degrading it

miR-146a and miR-146b in the diagnosis and prognosis of papillary thyroid carcinoma

The present study investigated the relationship between the expression of miR-146a and miR-146b with the occurrence and prognosis of papillary thyroid carcinoma. Experiments in vitro were also used to explore the effect of the knocked down expression of the miRNAs on growth and migration of papillary thyroid carcinoma cells. A total of 73 patients with papillary thyroid carcinoma admitted to Yidu Central Hospital of Weifang from September 2013 to September 2015 were enrolled in the study. Carcinoma samples were obtained from each patient, and adjacent tissues were used as control samples to determine expression levels of miR-146a and miR146b by semi-quantitative RT-PCR. An analysis was conducted to find possible correlations between the miRNAs expression levels and clinicopathological features in the patients followed up for one year after diagnosis. Additionally, to examine the function of miR-146a and miR-146b on TPC-1 cells, the expression of miRNAs was knocked down using specific siRNAs. MTT and Transwell assays were used to evaluate cell proliferation and migration, respectively, in the miRNA cell lines. Finally, western blot analysis was used to analyze the expression of IRAK1 in PTC cancer cells. Our results showed that the expression levels of miR-146a and miR-146b in carcinoma tissues were significantly higher than the levels in cancer-free tissues (P<0.01). The relative expression levels of miR-146a and miR-146b in cancerous tissues could be associated with the pathological type and presence or absence of lymph node metastasis (P<0.05). Compared with the siRNA-control cell, MTT and Transwell assays showed that the cell growth and migration of TPC-1 cells were decreased in miR-146a and miR-146b low expression cells (P<0.01). Western blot analysis showed that the expression of IRAK1 in papillary thyroid carcinoma was higher than in adjacent tissue (P<0.01). Based on our findings, the expression of miR-146a and miR-146b correlates with the occurrence and prognosis of papillary thyroid carcinoma, and the expression levels of miR-146a and miR-146b seem to affect the cell proliferation and migration and regulate the expression of IRAK1 protein in cancer cells. Further studies are needed to validate our results to provide new targets for prevention and treatment of papillary thyroid carcinoma.

miR-33a inhibits cell proliferation and invasion by targeting CAND1 in lung cancer

BACKGROUND

Lung cancer continues to be one of the top five causes of cancer-related mortality. This study aims to identify down- and upregulated miRNAs and mRNA which can be used as potential biomarkers and/or therapeutic targets for lung cancer.

METHODS

Integrated analysis of differential expression profiles of miRNA and mRNA in lung cancer was performed by searching Gene Expression Omnibus datasets. Based on miRNA expression profiles, direct mRNA targets of miRNAs with experimental support were identified through miRTarBase. The levels of representative miRNAs and mRNAs were confirmed through qualitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR).

RESULTS

The miR-33a was decreased in non-small cell lung cancer (NSCLC) tissues compared with the para-carcinoma tissues, whereas its target mRNA of cullin-associated NEDD8-dissociated protein 1 (CAND1) was increased in NSCLC tissues. Further research has shown that miR-33a can inhibit lung cancer cell proliferation, cell cycle progression, and migration by targeting CAND1. Moreover, the CAND1 knockout lung cancer cells showed similar results as cells transfected with miR-33a mimic.

CONCLUSIONS

These results suggested that the data mining based on online databases was an effective method in finding novel target in cancer research, and the miR-33a and CAND1 played an important role in lung cancer proliferation and cell migration.

miR-182 aids in receptive endometrium development in dairy goats by down-regulating PTN expression

Increasing evidence has shown that miRNAs play important roles in endometrium development during the menstrual cycle in humans and many other animals. Our previous data indicated that miR-182 levels increase 15.55-fold and pleiotrophin (PTN) levels decrease 20.97-fold in the receptive endometrium (RE, D15) compared with the pre-receptive endometrium (PE, D5) in dairy goats. The present study shows that miR-182 is widely expressed in different tissues of dairy goats and that its expression levels are regulated by E2 and P4 in endometrial epithelium cells (EECs). We confirmed that PTN is a target of miR-182 and that miR-182 regulates the protein levels of AKT, Bcl-2, FAS, MAPK, Caspase-3 and SP1 in EECs. Furthermore, miR-182 up-regulates or maintains the expression levels of osteopontin (OPN), cyclooxygenase-2 (COX-2) and prolactin receptor (PRLR) in EECs, suggesting that miR-182 is an important regulatory factor in the construction of endometrial receptivity in dairy goats. In conclusion, miR-182 participates in the development of endometrial receptivity by down-regulating PTN and affecting the expression of select apoptosis-related genes and increasing or maintaining the expression levels of OPN, COX-2 and PRLR in the EECs of dairy goats.

Circulating microRNA as a marker for predicting liver disease progression in patients with chronic hepatitis B

INTRODUCTION

Hepatitis B virus (HBV) constitutes an important risk factor for cirrhosis and hepatocellular carcinoma (HCC). The link between circulating microRNAs and HBV has been previously reported, although not as a marker of liver disease progression in chronic hepatitis B (CHB). The aim of this study was to characterize miRNA expression profiles between CHB with and without cirrhosis or HCC.

METHODS:

A total of 12 subjects were recruited in this study. We employed an Affymetrix Gene Chip miRNA 3.0 Array to provide universal miRNA coverage. We compared microRNA expression profiles between CHB with and without cirrhosis/HCC to discover possible prognostic markers associated with the progression of CHB.

RESULTS:

Our results indicated 8 differently expressed microRNAs, of which miRNA-935, miRNA-342, miRNA-339, miRNA-4508, miRNA-3615, and miRNA-3200 were up-regulated, whereas miRNA-182 and miRNA-4485 were down-regulated in patients with CHB who progressed to cirrhosis/HCC as compared to those without progression.

CONCLUSIONS:

We demonstrated the differential expression of miRNA-935, miRNA-342, miRNA-339, miRNA-4508, miRNA-3615, miRNA-3200, miRNA-182, and miRNA-4485 between patients with HBV without cirrhosis/HCC and those who had progressed to these more severe conditions. These miRNAs may serve as novel and non-invasive prognostic markers for early detection of CHB-infected patients who are at risk of progression to cirrhosis and/or HCC.

Posttranscriptional regulation of FOXO expression: microRNAs and beyond

Forkhead box, class O (FOXO) transcription factors are major regulators of diverse cellular processes, including fuel metabolism, oxidative stress response and redox signalling, cell cycle progression and apoptosis. Their activities are controlled by multiple posttranslational modifications and nuclear-cytoplasmic shuttling. Recently, post-transcriptional regulation of FOXO synthesis has emerged as a new regulatory level of their functions. Accumulating evidence suggests that this post-transcriptional mode of regulation of FOXO activity operates in response to stressful stimuli, including oxidative stress. Here, we give a brief overview on post-transcriptional regulation of FOXO synthesis by microRNAs (miRNAs) and by RNA-binding regulatory proteins, human antigen R (HuR) and quaking (QKI). Aberrant post-transcriptional regulation of FOXOs is frequently connected with various disease states. We therefore discuss characteristic examples of FOXO regulation at the post-transcriptional level under various physiological and pathophysiological conditions, including oxidative stress and cancer. The picture emerging from this summary points to a diversity of interactions between miRNAs/miRNA-induced silencing complexes and RNA-binding regulatory proteins. Better insight into these complexities of post-transcriptional regulatory interactions will add to our understanding of the mechanisms of pathological processes and the role of FOXO proteins.

LINKED ARTICLES

This article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc.

Relationship between miR-21 and miR-182 levels in peripheral blood and gastric cancer tissue

The relationship between miR-21 and miR-182 gene expression in peripheral blood and gastric cancer tissue was investigated, exploring the relationship between the levels of miR-21 and miR-182 and prognosis of gastric cancer patients, and determining the effects of these two genes on the growth and migration of gastric cancer cells. Fifty gastric cancer patients who were treated in the 254th Hospital of PLA, from July 2012 to July 2014 were selected. Peripheral blood samples were drawn from patients, and 50 healthy subjects were studied as controls. The levels of the miR-21 and miR-182 genes were detected by semi-quantitative PCR, and the correlation between miR-21 and miR-182 expression and clinicopathological features was explored. Moreover, the effects of miR-21 and miR-182 expression on the survival time and prognosis of patients were investigated. siRNA was used to downregulate miR-21 and miR-182 gene expression in MGC-803 gastric cancer cells, and MTT and Transwell assays were conducted. As a result, the relative expression levels of miR-21 and miR-182 in peripheral blood of gastric cancer patients were significantly higher than in healthy subjects (p<0.01) and the relative expression of miR-182 was closely related to the clinicopathological features of gastric cancer patients (p<0.05); high expression of miR-21 and miR-182 was associated with reduced survival time of patients (p<0.05); MGC-803 cells with low expression of miR-21 and miR-182 were analyzed, showing that miR-182 promoted cell proliferation and migration (p<0.01). In conclusion, the relative levels of miR-21 and miR-182 in peripheral blood of patients with gastric cancer are significantly increased; low expression of miR-182 can significantly reduce the proliferation and migration of gastric cancer cells. Moreover, miR-182 expression, which is closely related to the clinicopathological features of gastric cancer, can serve as a target for the clinical treatment of gastric cancer.

Computational Analysis of Specific MicroRNA Biomarkers for Noninvasive Early Cancer Detection

Cancer is a complex disease residing in various tissues of human body, accompanied with many abnormalities and mutations in genomes, transcriptome, and epigenome. Early detection plays a crucial role in extending survival time of all major cancer types. Recent advances in microarray and sequencing techniques have given more support to identifying effective biomarkers for early detection of cancer. MicroRNAs (miRNAs) are more and more frequently used as candidates for biomarkers in cancer related studies due to their regulation of target gene expression. In this paper, the comparative analysis is used to discover miRNA expression patterns in cancer versus normal samples on early stage of eight prevalent cancer types. Our work focuses on the specific miRNAs biomarkers identification and function analysis. Several identified miRNA biomarkers in this paper are matched well with those reported in existing researches, and most of them could serve as potential candidate indicators for clinical early diagnosis applications.