miR-212 increases tumor necrosis factor-related apoptosis-inducing ligand sensitivity in non-small cell lung cancer by targeting the antiapoptotic protein PED

Significance of TRAIL/Apo-2 ligand and its death receptors in apoptosis and necroptosis signalling: Implications for cancer-targeted therapeutics

The human immune defensesystem routinely expresses the tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), which is the most prevalent element for antitumor immunity. TRAIL associates with its death receptors (DRs), DR4 (TRAIL-R1), and DR5 (TRAIL-R2), in cancer cells to initiate the intracellular apoptosis cascade. Accordingly, numerous academic institutions and pharmaceutical companies havetried to exploreTRAIL's capacity to kill tumourcells by producing recombinant versions of it (rhTRAIL) or TRAIL receptor agonists (TRAs) [monoclonal antibody (mAb), synthetic and natural compounds, etc.] and molecules that sensitize TRAIL signalling pathway for therapeutic applications. Recently, several microRNAs (miRs) have been found to activate or inhibit death receptor signalling. Therefore, pharmacological regulation of these miRs may activate or resensitize the TRAIL DRs signal, and this is a novel approach for developing anticancer therapeutics. In this article, we will discuss TRAIL and its receptors and molecular pathways by which it induces various cell death events. We will unravel potential innovative applications of TRAIL-based therapeutics, and other investigated therapeutics targeting TRAIL-DRs and summarize the current preclinical pharmacological studies and clinical trials. Moreover, we will also emphasizea few situations where future efforts may be addressed to modulate the TRAIL signalling pathway.

Training vs. Tolerance: The Yin/Yang of the Innate Immune System

For almost nearly a century, memory functions have been attributed only to acquired immune cells. Lately, this paradigm has been challenged by an increasing number of studies revealing that innate immune cells are capable of exhibiting memory-like features resulting in increased responsiveness to subsequent challenges, a process known as trained immunity (known also as innate memory). In contrast, the refractory state of endotoxin tolerance has been defined as an immunosuppressive state of myeloid cells portrayed by a significant reduction in the inflammatory capacity. Both training as well tolerance as adaptive features are reported to be accompanied by epigenetic and metabolic alterations occurring in cells. While training conveys proper protection against secondary infections, the induction of endotoxin tolerance promotes repairing mechanisms in the cells. Consequently, the inappropriate induction of these adaptive cues may trigger maladaptive effects, promoting an increased susceptibility to secondary infections—tolerance, or contribute to the progression of the inflammatory disorder—trained immunity. This review aims at the discussion of these opposing manners of innate immune and non-immune cells, describing the molecular, metabolic and epigenetic mechanisms involved and interpreting the clinical implications in various inflammatory pathologies.

Bortezomib Inhibits Multiple Myeloma Cells by Transactivating ATF3 to Trigger miR-135a-5p- Dependent Apoptosis

Multiple myeloma (MM) is a malignant cancer with an increasing in incidence that can be alleviated through bortezomib (BTZ) treatment. Activating transcription factor 3 (ATF3) plays a major role in cancer development. Moreover, microRNAs (miRNAs) regulate carcinogenic pathways, apoptosis, and programmed necrotic cell death. However, the detailed mechanism by which ATF3 modulates BTZ drug sensitivity/resistance remains elusive. In the current study, expression of ATF3 was significantly increased under BTZ treatment in a dose-dependent manner in MM cell lines. In addition, ATF3 could regulate cell apoptosis under BTZ treatment. The effect of ATF3 was negatively regulated by its binding miRNA, miR-135a-5p. When either ATF3 was silenced or miR-135a-5p mimics were added to MM cells, they partially lost sensitivity to BTZ treatment. This was accompanied by low levels of Noxa, CHOP, and DR5, and a decrease in mitochondrial membrane potential. These results revealed the combinatorial regulatory patterns of ATF3 and miR-135a-5p in the regulatory protein interactome, which indicated a clinical significance of the miR-135a-5p-ATF3 protein interaction network in BTZ therapy. This study provides potential evidence for further investigation into BTZ resistance.

Ginsenoside Rh7 Suppresses Proliferation, Migration and Invasion of NSCLC Cells Through Targeting ILF3-AS1 Mediated miR-212/SMAD1 Axis

It is reported that ginsenosides have a significant anti-tumor effect on a variety of tumors. However, the role and mechanism of Rh7 in non-small cell lung cancer (NSCLC) are unclear. In this study, we aimed to study the anti-tumor effect of Rh7 on the proliferation and progression of NSCLC. Bioinformatics analysis showed that ILF3-AS1 was regulated by ginsenoside Rh7 in NSCLC. Down-regulation of ILF3-AS1 could significantly inhibit the proliferation, metastasis and invasion of NSCLC. In addition, ILF3-AS1 negatively controlled miR-212, which in turn targeted SMAD1 expression, thereby regulating NSCLC cell viability and apoptosis. Our results indicate that ILF3-AS1 can be used as a diagnostic and therapeutic target for non-small cell lung cancer. It is discovered for the first time that ginsenoside Rh7 inhibits the expression of ILF3-AS1 and exerts antitumor effects.

Comparative microRNA Transcriptomes in Domestic Goats Reveal Acclimatization to High Altitude

High-altitude acclimatization is a representative example of vertebrates' acclimatization to harsh and extreme environments. Previous studies reported sufficient evidence for a molecular genetic basis of high-altitude acclimatization, and genomic patterns of genetic variation among populations and species have been widely elucidated in recent years. However, understanding of the miRNA role in high-altitude acclimatization have lagged behind, especially in non-model species. To investigate miRNA expression alterations of goats that were induced by high-altitude stress, we performed comparative miRNA transcriptome analysis on six hypoxia-sensitive tissues (heart, kidney, liver, lung, skeletal muscle, and spleen) in two goat populations from distinct altitudes (600 and 3000 m). We obtained the expression value of 1391 mature miRNAs and identified 138 differentially expressed (DE) miRNAs between high and low altitudes. Combined with tissue specificity analysis, we illustrated alterations of expression levels among altitudes and tissues, and found that there were coexisting tissue-specific and -conserved mechanisms for hypoxia acclimatization. Notably, the interplay between DE miRNA and DE target genes strongly indicated post-transcriptional regulation in the hypoxia inducible factor 1, insulin, and p53 signaling pathways, which might play significant roles in high-altitude acclimatization in domestic goats. It's also worth noting that we experimentally confirmed miR-106a-5p to have a negative regulation effect on angiogenesis by directly targeting FLT-1. These results provide insight into the complicated miRNA expression patterns and regulatory mechanisms of high-altitude acclimatization in domestic goats.

Noncoding RNAs: the shot callers in tumor immune escape

Immunotherapy, designed to exploit the functions of the host immune system against tumors, has shown considerable potential against several malignancies. However, the utility of immunotherapy is heavily limited due to the low response rate and various side effects in the clinical setting. Immune escape of tumor cells may be a critical reason for such low response rates. Noncoding RNAs (ncRNAs) have been identified as key regulatory factors in tumors and the immune system. Consequently, ncRNAs show promise as targets to improve the efficacy of immunotherapy in tumors. However, the relationship between ncRNAs and tumor immune escape (TIE) has not yet been comprehensively summarized. In this review, we provide a detailed account of the current knowledge on ncRNAs associated with TIE and their potential roles in tumor growth and survival mechanisms. This review bridges the gap between ncRNAs and TIE and broadens our understanding of their relationship, providing new insights and strategies to improve immunotherapy response rates by specifically targeting the ncRNAs involved in TIE.

miR-23a-3p and miR-23a-5p target CiGadd45ab to modulate inflammatory response and apoptosis in grass carp

Ctenopharyngodon idella growth arrest and DNA damage-inducible 45 ab (CiGadd45ab) is a subtype of the Gadd45a gene of the Gadd45 family in grass carp. There is increasing evidence that microRNAs (miRNAs) are involved in the regulation of inflammatory and apoptotic responses. However, little is known about the regulatory effects of miRNAs on CiGadd45ab expression. In the present study, CiGadd45ab was identified as a target gene of miR-23a-3p and miR-23a-5p, based on miRNA expression profiling and a dual-luciferase reporter assay. In addition, miR-23a-3p and miR-23a-5p were both confirmed to be involved in the inflammatory response following infection with Aeromonas hydrophila by targeting CiGadd45ab. Transfection with miR-23a-3p and miR-23a-5p mimics and inhibitor altered proinflammatory gene expression and apoptosis rate, thereby suggesting that miRNAs regulate immune response and anti-apoptosis by targeting CiGadd45ab in grass carp. Our results provide a theoretical basis for exploring the molecular mechanisms by which miR-23a-3p and miR-23a-5p target CiGadd45ab to regulate inflammation and apoptosis against bacterial infection in grass carp.

The functions and targets of miR-212 as a potential biomarker of cancer diagnosis and therapy

Cancer is a major health problem worldwide. An increasing number of researchers are studying the diagnosis, therapy and mechanisms underlying the development and progression of cancer. The study of noncoding RNA has attracted a lot of attention in recent years. It was found that frequent alterations of miRNA expression not only have various functions in cancer but also that miRNAs can act as clinical markers of diagnosis, stage and progression of cancer. MiR-212 is an important example of miRNAs involved in cancer. According to recent studies, miR-212 may serve as an oncogene or tumour suppressor by influencing different targets or pathways during the oncogenesis and the development and metastasis of cancer. Its deregulation may serve as a marker for the diagnosis or prognosis of cancer. In addition, it was recently reported that miR-212 was related to the sensitivity or resistance of cancer cells to chemotherapy or radiotherapy. Here, we summarize the current understanding of miR-212 functions in cancer by describing the relevant signalling pathways and targets. The role of miR-212 as a biomarker and its therapeutic potential in cancer is also described. The aim of this review was to identify new methods for the diagnosis and treatment of human cancers.

Synergistic Autophagy Effect of miR-212-3p in Zoledronic Acid-Treated In Vitro and Orthotopic In Vivo Models and in Patient-Derived Osteosarcoma Cells

Osteosarcoma (OS) originates from osteoid bone tissues and is prone to metastasis, resulting in a high mortality rate. Although several treatments are available for OS, an effective cure does not exist for most patients with advanced OS. Zoledronic acid (ZOL) is a third-generation bisphosphonate that inhibits osteoclast-mediated bone resorption and has shown efficacy in treating bone metastases in patients with various types of solid tumors. Here, we sought to clarify the mechanisms through which ZOL inhibits OS cell proliferation. ZOL treatment inhibited OS cell proliferation, viability, and colony formation. Autophagy inhibition by RNA interference against Beclin-1 or ATG5 inhibited ZOL-induced OS cell death. ZOL induced autophagy by repressing the protein kinase B/mammalian target of rapamycin/p70S6 kinase pathway and extracellular signal-regulated kinase signaling-dependent autophagy in OS cell lines and patient-derived OS cells. Microarrays of miRNA showed that ZOL increased the levels of miR-212-3p, which is known to play an important role in autophagy, in OS in vitro and in vivo systems. Collectively, our data provided mechanistic insight into how increased miR-212-3p through ZOL treatment induces autophagy synergistically in OS cells, providing a preclinical rationale for conducting a broad-scale clinical evaluation of ZOL + miR-212-3p in treating OS.

Potential and Challenges of Aptamers as Specific Carriers of Therapeutic Oligonucleotides for Precision Medicine in Cancer

Due to the progress made in the area of precision and personalized medicine in the field of cancer therapy, strategies to selectively and specifically identify target molecules causative of the diseases are urgently needed. Efforts are being made by a number of different laboratories, companies, and researchers to develop therapeutic molecules that selectively recognize the tissues and the cells of interest, exhibit few or no off-target and side effects, are non-immunogenic, and have a strong action. Aptamers, artificially selected single-stranded DNA or RNA oligonucleotides, are promising molecules satisfying many of the requirements needed for diagnosis and precision medicine. Aptamers can also couple to their native mechanism of action the delivery of additional molecules (oligonucleotides, siRNAs, miRNAs) to target cells. In this review, we summarize recent progress in the aptamer-mediated strategy for the specific delivery of therapeutic oligonucleotides.

Effects of AntagomiRs on Different Lung Diseases in Human, Cellular, and Animal Models

INTRODUCTION

MiRNAs have been shown to play a crucial role among lung cancer, pulmonary fibrosis, tuberculosis (TBC) infection, and bronchial hypersensitivity, thus including chronic obstructive pulmonary disease (COPD) and asthma. The oncogenic effect of several miRNAs has been recently ruled out. In order to act on miRNAs turnover, antagomiRs have been developed.

MATERIALS AND METHODS

The systematic review was conducted under the PRISMA guidelines (registration number is: CRD42019134173). The PubMed database was searched between 1 January 2000 and 30 April 2019 under the following search strategy: (((antagomiR) OR (mirna antagonists) OR (mirna antagonist)) AND ((lung[MeSH Terms]) OR ("lung diseases"[MeSH Terms]))). We included original articles, published in English, whereas exclusion criteria included reviews, meta-analyses, single case reports, and studies published in a language other than English.

RESULTS AND CONCLUSIONS

A total of 68 articles matching the inclusion criteria were retrieved. Overall, the use of antagomiR was seen to be efficient in downregulating the specific miRNA they are conceived for. The usefulness of antagomiRs was demonstrated in humans, animal models, and cell lines. To our best knowledge, this is the first article to encompass evidence regarding miRNAs and their respective antagomiRs in the lung, in order to provide readers a comprehensive review upon major lung disorders.

Upregulation of MiR-212 Inhibits Migration and Tumorigenicity and Inactivates Wnt/β-Catenin Signaling in Human Hepatocellular Carcinoma

BACKGROUND

MicroRNAs are involved in hepatocellular carcinoma metastasis, a principal cause of hepatocellular carcinoma-related death in patients worldwide. MiR-212 is a microRNA that has been identified in several types of cancers and is postulated to influence cell signaling and subsequent malignant pathogenesis. Despite emerging reports suggesting that miR-212 plays a significant role in the onset, progression, and migration of these types of malignant tumors, its involvement in the development of hepatocellular carcinoma has not been fully elucidated.

MATERIALS AND METHODS

Quantitative reverse transcription polymerase chain reaction, wound healing, transwell migration and invasion assays, Western blotting, and xenograft tumor growth models were performed to test the expression levels and functions of miR-212 in hepatocellular carcinoma. Luciferase reporter assay, quantitative reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry were used to identify and verify the target of miR-212.

RESULTS

In this study, we identify significant repression of miR-212 in hepatocellular carcinoma and demonstrate that overexpression of miR-212 inhibits the migration of hepatocellular carcinoma cells in vitro and in vivo. Furthermore, we identify forkhead box M1, whose expression is inversely related to that of miR-212, as a direct target of miR-212. Additionally, reexpression of forkhead box M1 rescues the miR-212-mediated inhibition of cell migration. We observed that inhibition of miR-212 activates forkhead box M1 but inhibits the Wnt/β-catenin pathway by suppressing Wnt, LEF-1, c-Myc, and nuclear β-catenin. Finally, in vivo studies confirmed the inhibitory effect of miR-212 on hepatocellular carcinoma growth.

CONCLUSION

Our present findings indicate that miR-212 is a potential prognostic biomarker of hepatocellular carcinoma and that the miR-212/forkhead box M1 regulatory axis may represent a new therapeutic objective for hepatocellular carcinoma treatment.

Next-Generation Sequencing Reveals the Role of Epigallocatechin-3-Gallate in Regulating Putative Novel and Known microRNAs Which Target the MAPK Pathway in Non-Small-Cell Lung Cancer A549 Cells

Lung cancer constitutes 85% of non-small cell lung cancer diagnosed cases. MicroRNAs are novel biomarkers that are capable of modulating multiple oncogenic pathways. Epigallocatechin-3-gallate (EGCG) is a potent chemopreventive and chemotherapeutic agent for cancer. We aimed to identify important known and putative novel microRNAs modulated by EGCG in A549 cells using next-generation sequencing and identify their gene targets. Preliminary analysis revealed an IC50 value of 309 μM with G0/G1 phase arrest at 40 μM EGCG treatment. MicroRNA profiling identified 115 known and 4 putative novel microRNAs in 40 μM and 134 known and 3 putative novel microRNAs in 100 μM EGCG-treated A549 cells. The top 10 up-expressed microRNAs were similar between the untreated control and EGCG-treated A549 cells. An up-expression in oncogenic microRNAs, which belong to broadly conserved seed families, were observed in untreated control and EGCG-treated A549 cells. Kyoto Encyclopedia of Genes and Genomes and Protein Analysis Through Evolutionary Relationships pathway analyses of the validated microRNA targeting genes strengthened the hypothesis that EGCG treatment can modulate microRNAs that play a significant role in the MAPK signaling pathway. Expression profile of microRNAs was validation by quantitative real time PCR of randomly selected microRNAs. This study identified signature microRNAs that can be used as novel biomarkers for lung cancer diagnosis.

MicroRNA-212 promotes the recovery function and vascular regeneration of endothelial progenitor cells in mice with ischemic stroke through inactivation of the notch signaling pathway via downregulating MMP9 expression

Ischemic stroke is a refractory disease caused by cerebral ischemic injury, which results in brain dysfunction. This study intends to investigate the effects of microRNA-212 (miR-212) on the recovery function and vascular regeneration of endothelial progenitor cells (EPCs) by inactivation of the Notch signaling pathway by binding to matrix metallopeptidase 9 (MMP9) in mice with ischemic stroke. According to the results of database retrieval systems and data analysis, MMP9 was predicted as a gene related to ischemic stroke and miR-212 is a potential regulating mRNA of MMP9. All 72 healthy adult C57BL6 mice were selected for middle cerebral artery occlusion (MCAO) establishment. Cerebral infarction was observed under triphenyltetrazolium chloride staining. A series of inhibitors, activators, and siRNAs were introduced to the verified regulatory functions for miR-212 governing MMP9 in ischemic stroke. Cell proliferation was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and tube-forming ability by tubule formation test. Reverse transcription quantitative polymerase chain reaction and Western blot analysis were used to detect the expressions of miR-212, MMP9, Hes-1, and Notch-1. The corresponding results demonstrated that the area of cerebral infarction and the number of neuronal necrosis increased in the MCAO group in contrast to the sham group. Meanwhile, upregulation of miR-212 or downregulation of MMP9 decreases the expressions of MMP9, Hes-1 Notch-1, increases cell proliferation and tube-forming ability and improves the pathological conditions of EPCs. Our study suggests that miR-212 promotes recovery function and vascular regeneration of EPCs through negative regulation of the Notch signaling pathway via downregulating expression of MMP9, thus provides a clinical theoretical basis for ischemic stroke therapy.

Delivery of miR-212 by chimeric peptide-condensed supramolecular nanoparticles enhances the sensitivity of pancreatic ductal adenocarcinoma to doxorubicin

Pancreatic ductal adenocarcinoma (PDAC) is a destructive cancer with poor prognosis. Both novel therapeutic targets and approaches are needed to improve the overall survival of PDAC patients. MicroRNA-212 (miR-212) has been reported as a tumor suppressor in multiple cancers, but its definitive role and exact mechanism in the progression of pancreatic cancer is unclear. In this study, we developed a new chimeric peptide (PL-1) composed of plectin-1-targeted PDAC-specific and arginine-rich RNA-binding motifs which could condense miRNA to self-assemble supramolecular nanoparticles. These nanoparticles could deliver miR-212 into PDAC cells specifically and efficiently which also showed good stability in RNase and serum. Moreover, we demonstrated that PL-1/miR-212 nanoparticles could dramatically enhance the chemotherapeutic effect of doxorubicin for PDAC both in vitro and in vivo. In terms of mechanism, combined miR-212 intervention by PL-1/miR-212 nanoparticles resulted in obvious decrease of USP9X expression (ubiquitin specific peptidase 9, X-linked, USP9X) and eventually enhanced the doxorubicin induced apoptosis and autophagy of PDAC cells. These findings provide a new promising anti-cancer strategy via PL-1/miR-212 nanoparticles and identify miR-212/USP9X as a new potential target for future systemic therapy against human PDAC.

MicroRNA in lung cancer: role, mechanisms, pathways and therapeutic relevance

Lung cancer is the cardinal cause of cancer-related deaths with restricted recourse of therapy throughout the world. Clinical success of therapies is not very promising due to - late diagnosis, limited therapeutic tools, relapse and the development of drug resistance. Recently, small ∼20-24 nucleotides molecules called microRNAs (miRNAs) have come into the limelight as they play outstanding role in the process of tumorigenesis by regulating cell cycle, metastasis, angiogenesis, metabolism and apoptosis. miRNAs essentially regulate gene expression via post-transcriptional regulation of mRNA. Nevertheless, few studies have conceded the role of miRNAs in activation of gene expression. A large body of data generated by numerous studies is suggestive of their tumor-suppressing, oncogenic, diagnostic and prognostic biomarker roles in lung cancer. They have also been implicated in regulating cancer cell metabolism and resistance or sensitivity towards chemotherapy and radiotherapy. Further, miRNAs have also been convoluted in regulation of immune checkpoints - Programmed death 1 (PD-1) and its ligand (PD-L1). These molecules play a significant role in tumor immune escape leading to the generation of a microenvironment favouring tumor growth and progression. Therefore, it is imperative to explore the expression of miRNA and understand its relevance in lung cancer and development of anti-cancer strategies (anti - miRs, miR mimics and micro RNA sponges). In view of the above, the role of miRNA in lung cancer has been dissected and the associated mechanisms and pathways are discussed in this review.

Nicotine upregulates FGFR3 and RB1 expression and promotes non-small cell lung cancer cell proliferation and epithelial-to-mesenchymal transition via downregulation of miR-99b and miR-192

BACKGROUND

Tobacco smoke is by far the greatest risk factor for non-small-cell lung cancer (NSCLC). Nicotine, an active alkaloid in tobacco, is unable to initiate tumorigenesis in humans and rodents, but can promote the growth and metastasis of various tumors, including NSCLC, initiated by tobacco carcinogens. Recently, cigarette smoke is reported to downregulate 24 miRNAs more than 3-fold in the lungs of rats, and most of these downregulated miRNAs are associated with NSCLC initiation and development. Nicotine as the major tobacco component might be associated with the expression changes of some miRNAs.

METHODS

qRT-PCR was performed to determine the miRNA and mRNA expression, and western blot was conducted to measure protein expression. MTT assay was used to detect cell proliferation.

RESULTS

The effects of nicotine on the expression of 24 miRNAs in NSCLC cell lines were determined, and the results showed that nicotine treatment decreased miR-99b and miR-192 expression. Cell proliferation and epithelial-to-mesenchymal transition (EMT) detection showed that nicotine promoted NSCLC cell proliferation and EMT, and restoration of miR-99b or miR-192 expression relieved the effects of nicotine on NSCLC cell proliferation and EMT. Subsequently, fibroblast growth factor receptor 3 (FGFR3) and retinoblastoma 1 (RB1) were confirmed to be the targets of miR-99b and miR-192, respectively, and were upregulated by nicotine in NSCLC cells. In addition, FGFR3 or RB1 knockdown inhibited NSCLC cell proliferation and EMT.

CONCLUSION

This study, for the first time, elucidates nicotine-miR-99b/miR-192-FGFR3/RB1 regulatory network that nicotine promotes NSCLC cell proliferation and EMT by downregulating miR-99b and miR-192, and upregulating their targets FGFR3 and RB1. These findings offer novel insights into the understanding of underlying molecular mechanisms of NSCLC related with the nicotine effects.

MicroRNA, epigenetic machinery and lung cancer

Lung cancer is the leading cause of cancer deaths worldwide and over 80% of lung cancer patients are classified as having non-small cell lung cancer. Although there have been technological advancements in the early detection and standard treatment of lung cancer, it is often diagnosed at an advanced stage and is chemoresistant to most available drugs. A number of studies have demonstrated that microRNA is able to modulate various tumorigenic processes, including progression and metastasis, in various mechanisms. In this review we examine the most recent achievements in microRNA and lung cancer treatment and summarize the research progress on the reciprocal regulation between microRNA and epigenetic modifications, as both have been intensively studied in lung cancer. Epigenetic modifications on the human genome regulate gene and microRNA expression at the transcriptional level; inversely, microRNA can also transcriptionally cleave and/or translationally repress the expression of several key enzymes involved in epigenetic processes such as DNA methylation and histone modification. Better understanding of reciprocal regulation between microRNA and epigenetic modifications will underlie the development of novel microRNA orientated diagnostic and therapeutic strategies relating to lung cancer in the near future.

MicroRNA-212 activates hepatic stellate cells and promotes liver fibrosis via targeting SMAD7

There has been an increasing number of researches about microRNAs (miRNAs) in the progression of liver fibrosis from the point of their comprehensive functions in regulating the activation of hepatic stellate cells (HSCs). Among them, it has been reported that miR-212 is up-regulated in activated rat primary HSCs. However, its mechanism has not been determined yet. Here, we confirmed that the level of miR-212-3p was up-regulated in livers of carbon tetrachloride (CCl₄)-treated mice compared with the normal control, which is a classical model of chronically damaged fibrotic liver. In vitro, we demonstrated that TGF-β, a master fibrogenic cytokine, could induce the level of miR-212. In turn, overexpression of miR-212 could induce the activation marker of HSC including α-smooth muscle actin (α-SMA) and collagens by activating TGF-β signaling pathway. Furthermore, SMAD7, a dominant suppressor of TGF-β pathway, was identified as a direct target of miR-212-3p. Our results indicate that miR-212-3p facilitates the activation of HSCs and TGF-β pathway by targeting SMAD7, highlighting that it can be served as a novel biomarker or therapeutic target for liver fibrosis.

Presenilin1/γ-secretase protects neurons from glucose deprivation-induced death by regulating miR-212 and PEA15

Reduced cerebral glucose utilization is found in aged individuals and often is an early sign of neurodegeneration. Here, we show that under glucose deprivation (GD) conditions, decreased expression of presenilin 1 (PS1) results in decreased neuronal survival, whereas increased PS1 increases neuronal survival. Inhibition of γ-secretase also decreases neuronal survival under GD conditions, which suggests the PS1/γ-secretase system protects neurons from GD-induced death. We also show that neuronal levels of the survival protein, phosphoprotein enriched in astrocytes at ∼15 kDa (PEA15), and its mRNA are regulated by PS1/γ-secretase. Furthermore, down-regulation of PEA15 decreases neuronal survival under reduced glucose conditions, whereas exogenous PEA15 increases neuronal survival even in the absence of PS1, which indicates that PEA15 promotes neuronal survival under GD conditions. The absence or reduction of PS1, as well as γ-secretase inhibitors, increases neuronal miR-212, which targets PEA15 mRNA. PS1/γ-secretase activates the transcription factor, cAMP response element-binding protein, regulating miR-212, which targets PEA15 mRNA. Taken together, our data show that under conditions of reduced glucose, the PS1/γ-secretase system decreases neuronal losses by suppressing miR-212 and increasing its target survival factor, PEA15. These observations have implications for mechanisms of neuronal death under conditions of reduced glucose and may provide targets for intervention in neurodegenerative disorders.-Huang, Q., Voloudakis, G., Ren, Y., Yoon, Y., Zhang, E., Kajiwara, Y., Shao, Z., Xuan, Z., Lebedev, D., Georgakopoulos, A., Robakis, N. K. Presenilin1/γ-secretase protects neurons from glucose deprivation-induced death by regulating miR-212 and PEA15.

MicroRNA-212/ABCG2-axis contributes to development of imatinib-resistance in leukemic cells

BCR-ABL-independent resistance against tyrosine kinase inhibitor is an emerging problem in therapy of chronic myeloid leukemia. Such drug resistance can be linked to dysregulation of ATP-binding cassette (ABC)-transporters leading to increased tyrosine kinase inhibitor efflux, potentially caused by changes in microRNA expression or DNA-methylation. In an in vitro-imatinib-resistance model using K-562 cells, microRNA-212 was found to be dysregulated and inversely correlated to ABC-transporter ABCG2 expression, targeting its 3'-UTR. However, the functional impact on drug sensitivity remained unknown. Therefore, we performed transfection experiments using microRNA-mimics and -inhibitors and investigated their effect on imatinib-susceptibility in sensitive and resistant leukemic cell lines. Under imatinib-treatment, miR-212 inhibition led to enhanced cell viability (p = 0.01), reduced apoptosis (p = 0.01) and cytotoxicity (p = 0.03). These effects were limited to treatment-naïve cells and were not observed in cells, which were resistant to various imatinib-concentrations (0.1 μM to 2 μM). Further analysis in treatment-naïve cells revealed that miR-212 inhibition resulted in ABCG2 upregulation and increased ABCG2-dependent efflux. Furthermore, we observed miR-212 promoter hypermethylation in 0.5 and 2 μM IM-resistant sublines, whereas ABCG2 methylation status was not altered. Taken together, the miR-212/ABCG2-axis influences imatinib-susceptibility contributing to development of imatinib-resistance. Our data reveal new insights into mechanisms initiating imatinib-resistance in leukemic cells.

MicroRNA-212 inhibits the proliferation, migration and invasion of renal cell carcinoma by targeting X-linked inhibitor of apoptosis protein (XIAP)

MicroRNAs have been found to be critical regulator of cancer cell biology. MicroRNA-212 (miR-212) was identified to be a critical cancer-associated microRNA playing either oncogenic functions or tumor suppressive roles in different types of human cancers. In this study, we found that the level of miR-212 in renal cell carcinoma (RCC) tissues was significantly lower than that in adjacent non-tumor tissues. Decreased level of miR-212 was associated with advanced T stage and TNM stage of RCC. The expression of miR-212 was decreased in RCC cell lines as compared with the HK-2 cell line. Overexpression of miR-212 inhibited cell viability, proliferation, migration and invasion of CAKI-2 cells. Knockdown of miR-212 increased cell viability and proliferation, migration and invasion of ACHN cells. In vivo experiments showed that miR-212 inhibited the proliferation and promoted the apoptosis of ACHN cells in nude mice and thus inhibited the in vivo tumor growth of CAKI-2 cells. Furthermore, we confirmed that X-linked inhibitor of apoptosis protein (XIAP) was the downstream target of miR-212. The expression level of miR-212 was negatively correlated with XIAP expression in RCC tissues. Moreover, XIAP mediated the tumor suppressive roles of miR-212 in RCC. Finally, we demonstrated that the aberrant expression of miR-212 and XIAP was evidently correlated with poor prognosis of RCC patients. In all, miR-212 can act as a prognostic biomarker for RCC patients and inhibits the growth and metastasis of RCC cells by inhibiting XIAP.

miR-133a Promotes TRAIL Resistance in Glioblastoma via Suppressing Death Receptor 5 and Activating NF-κB Signaling

Recombinant tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), as a novel cancer therapeutic, is being tested in phase II and III clinical trials; however, TRAIL resistance remains a big obstacle preventing its clinical application. Considering that TRAIL-induced apoptosis through death receptors DR4 and DR5, their activation may be an alternative pathway to suppress TRAIL resistance. In this study, a negative correlation between DR5 expression and TRAIL resistance was observed, and miR-133a was predicted to be the most promising candidate to suppress DR5 expression. Further investigation demonstrated that miR-133a knockdown dramatically suppressed TRAIL resistance in glioblastoma in vitro and in vivo. An NF-κB family member, phosphorylated IκBα (P-IκBα), was shown to be stimulated by miR-133a, leading to the activation of this signaling. Finally, miR-133a was found to be inversely correlated with DR5 expression in human clinical specimens. In conclusion, our data demonstrate that miR-133a promotes TRAIL resistance in glioblastoma by suppressing DR5 expression and activating NF-κB signaling.

Next-Generation CDK2/9 Inhibitors and Anaphase Catastrophe in Lung Cancer

Background

The first generation CDK2/7/9 inhibitor seliciclib (CYC202) causes multipolar anaphase and apoptosis in lung cancer cells with supernumerary centrosomes (known as anaphase catastrophe). We investigated a new and potent CDK2/9 inhibitor, CCT68127 (Cyclacel).

Methods

CCT68127 was studied in lung cancer cells (three murine and five human) and control murine pulmonary epithelial and human immortalized bronchial epithelial cells. Robotic CCT68127 cell-based proliferation screens were used. Cells undergoing multipolar anaphase and inhibited centrosome clustering were scored. Reverse phase protein arrays (RPPAs) assessed CCT68127 effects on signaling pathways. The function of PEA15, a growth regulator highlighted by RPPAs, was analyzed. Syngeneic murine lung cancer xenografts (n = 4/group) determined CCT68127 effects on tumorigenicity and circulating tumor cell levels. All statistical tests were two-sided.

Results

CCT68127 inhibited growth up to 88.5% (SD = 6.4%, P < .003) at 1 μM, induced apoptosis up to 42.6% (SD = 5.5%, P < .001) at 2 μM, and caused G1 or G2/M arrest in lung cancer cells with minimal effects on control cells (growth inhibition at 1 μM: 10.6%, SD = 3.6%, P = .32; apoptosis at 2 μM: 8.2%, SD = 1.0%, P = .22). A robotic screen found that lung cancer cells with KRAS mutation were particularly sensitive to CCT68127 ( P = .02 for IC 50 ). CCT68127 inhibited supernumerary centrosome clustering and caused anaphase catastrophe by 14.1% (SD = 3.6%, P < .009 at 1 μM). CCT68127 reduced PEA15 phosphorylation by 70% (SD = 3.0%, P = .003). The gain of PEA15 expression antagonized and its loss enhanced CCT68127-mediated growth inhibition. CCT68127 reduced lung cancer growth in vivo ( P < .001) and circulating tumor cells ( P = .004). Findings were confirmed with another CDK2/9 inhibitor, CYC065.

Conclusions

Next-generation CDK2/9 inhibition elicits marked antineoplastic effects in lung cancer via anaphase catastrophe and reduced PEA15 phosphorylation.

The biological functions and mechanism of miR‑212 in prostate cancer proliferation, migration and invasion via targeting Engrailed-2

Accumulating evidence indicates that Engrailed-2 (EN-2), which is a homeobox-containing transcription factor, act as a candidate oncogene in prostate cancer (PCa). Even though there are some treatments targeting EN-2, however, it is limited because the mechanism of EN-2 upregulation in PCa cells is still unknown. In this study, we investigate the role of miR‑212 on EN-2 expression and explored the mechanism of prostate cancer survival and metastasis. The relative expression levels of miR‑212 and EN-2 in PCa samples and adjacent normal tissues as well as in PCa cell lines were detected by using quantitative real-time PCR. CCK-8, TUNEL and Transwell assays were used to analyze cell proliferation, apoptosis and invasion, respectively. EN-2 was identified as a direct target of miR‑212 via luciferase reporter and western blot assays. Results showed that the expression level of miR‑212 was downregulated in both PCa samples and PCa cell lines when compared with prostate epithelial cells and the adjacent no tumor tissues. Moreover, we found that overexpression of miR‑212 suppressed PCa cell proliferation and invasion, promoted PCa cell apoptosis. EN-2 was identified as a direct target gene of miR‑212 by using luciferase reporter and western blot assays. Also, the expression of EN-2 and miR‑212 in the PCa cells had an opposite correlation. The critical role of miR‑212 in inhibiting prostate tumor growth was verified in xenograft models of prostate cancer. These findings highlighted the role of miR‑212 in PCa progression. More importantly, we speculate that EN-2 is a direct target gene of miR‑212.

A new insight on reciprocal relationship between microRNA expression and epigenetic modifications in human lung cancer

Lung cancer stands among the leading causes of cancer-related death in the world. Although the molecular network implicated in lung cancer development is extensively revealed, the mortality rate is only slightly improved. MicroRNAs are small, endogenous single-stranded evolutionary conserved non-coding RNAs which involve in a wide variety of biological processes including cell growth, proliferation, metabolism, and differentiation. MicroRNAs, as novel biomarkers, have multiple functions in normal lung tissue development, and aberrant expression profiles of certain microRNAs could induce lung tumorigenesis. Similar to that of protein-coding genes, microRNA expression and function are regulated by multiple factors as well as the epigenetic network including DNA methylation and histone modification mechanisms. Furthermore, microRNAs can themselves regulate key enzymes which drive epigenetic modifications and have a pivotal effect on the cell biology. In this review, we will look into the regulatory loop linkage between microRNA expression and epigenetic modifications, and then, we will discuss the effects of epigenetics on the miRNome, as well as the role of epi-microRNAs in controlling the epigenome in human lung cancer. Better knowledge of reciprocal connection between microRNAs and epigenome will help to develop novel microRNA-orientated diagnostic, prognostic and therapeutic strategies related to human lung cancer in future.

MicroRNA-212 inhibits the metastasis of nasopharyngeal carcinoma by targeting SOX4

MicroRNAs are important factors in the pathogenic processes of human types of cancers including nasopharyngeal carcinoma (NPC). In the present study, we confirmed that the microRNA-212 expression level was significantly decreased both in NPC tissues and NPC cell lines. Decreased expression of miR-212 was associated with advanced tumor-node-metastasis (TNM) stage and metastasis of NPC. Patients with a lower level of miR-212 had significantly decreased rates of overall and disease-free survival. Functional experiments showed that forced expression of miR-212 inhibited the migration and invasion of NPC cells while inhibition of miR-212 increased the migration and invasion of NPC cells. Furthermore, the results of luciferase assay, qRT-PCR and western blotting showed that SOX4 was the direct downstream target of miR-212 in NPC cells. In addition, we further confirmed that miR-212 exerted its inhibitory influence on the migration and invasion of NPC cells by targeting SOX4.

microRNA-664 enhances proliferation, migration and invasion of lung cancer cells

Altered microRNA (miR) expression serves an important role in the development and progression of lung cancer. In the present study, the effect of miR-664 on proliferation, migration and invasion of lung cancer cells was assessed. The proliferation of lung cancer cells with an overexpression of miR-664 was examined via MTT assay. The Caspase-Glo3/7 assay was used to examine the effect of miR-664 on cisplatin-induced apoptosis in lung cancer cells. The migration and invasion of lung cancer cells were assessed by Transwell migration and matrigel invasion assays. Western blot analysis was used to examine the protein expression levels. miR-664 improved the proliferation of lung cancer cells and inhibited cisplatin-induced apoptosis of A549 and A427 cells. Furthermore, altered expression of miR-664 affected migration and invasion of lung cancer cells. In addition, a miR-664 mimic decreased E-cadherin expression and increased vementin and Snail expression in lung cancer cells. Notably, the expression level of protein kinase B in A549 cells was changed following altered expression of miR-664. The results of the present study suggest that miR-664 serves an essential role in tumor development and progression in lung cancer.

Chaperone-mediated autophagy substrate proteins in cancer

All intracellular proteins undergo continuous synthesis and degradation. Chaperone-mediated autophagy (CMA) is necessary to maintain cellular homeostasis through turnover of cytosolic proteins (substrate proteins). This degradation involves a series of substrate proteins including both cancer promoters and suppressors. Since activating or inhibiting CMA pathway to treat cancer is still debated, targeting to the CMA substrate proteins provides a novel direction. We summarize the cancer-associated substrate proteins which are degraded by CMA. Consequently, CMA substrate proteins catalyze the glycolysis which contributes to the Warburg effect in cancer cells. The fact that the degradation of substrate proteins based on the CMA can be altered by posttranslational modifications such as phosphorylation or acetylation. In conclusion, targeting to CMA substrate proteins develops into a new anticancer therapeutic approach.

Targetting PED/PEA-15 for diabetes treatment

INTRODUCTION

PED/PEA-15 is an ubiquitously expressed protein, involved in the regulation of proliferation and apoptosis. It is commonly overexpressed in Type 2 Diabetes (T2D) and in different T2D-associated comorbidities, including cancer and certain neurodegenerative disorders. Areas covered: In mice, Ped/Pea-15 overexpression impairs glucose tolerance and, in combination with high fat diets, further promotes insulin resistance and T2D. It also controls β-cell mass, altering caspase-3 activation and the expression of pro- and antiapoptotic genes. These changes are mediated by PED/PEA-15-PLD1 binding. Overexpression of PLD1 D4 domain specifically blocks Ped/Pea-15-PLD1 interaction, reverting the effect of Ped/Pea-15 in vivo. D4α, a D4 N-terminal peptide, is able to displace Ped/Pea-15-PLD1 binding, but features greater stability in vivo compared to the entire D4 peptide. Here, we review early mechanistic studies on PED/PEA-15 relevance in apoptosis before focusing on its role in cancer and T2D. Finally, we describe potential therapeutic opportunities for T2D based on PED/PEA-15 targeting. Expert opinion: T2D is a major problem for public health and economy. Thus, the identification of new molecules with pharmacological activity for T2D represents an urgent need. Further studies with D4α will help to identify smaller pharmacologically active peptides and innovative molecules of potential pharmacological interest for T2D treatment.

MicroRNA-132/212 Upregulation Inhibits TGF-β-Mediated Epithelial-Mesenchymal Transition of Prostate Cancer Cells by Targeting SOX4

BACKGROUND

MicroRNAs (miRNAs) are noncoding RNAs that are important for embryonic stem cell development and epithelial to mesenchymal transition (EMT). Accumulating evidence indicates that miRNAs play critical roles in prostate cancer (PCa) metastasis and have potential use as therapeutic targets. Although dysregulated miR-132/212 have been suggested to be directly involved in the proliferation and invasion of multiple malignancies, the exact role of miR-132/212 in PCa has not yet been fully understood.

METHODS

Real-time quantitative PCR (RT-qPCR) and bioinformatics analysis were used to validate the expression levels of miR-132/212 in PCa cell lines as well as in prostatic tissues. The biological function of miR-132/212 was evaluated by MTS, transwell, and wound healing assays, respectively. RT-qPCR and Western blot were used to study the transcript and protein expression levels. Bioinformatics tools and luciferase reporter assay were utilized to identify the molecular target of miR-132/212. Immunohistochemistry (IHC) was used to detect the expression of SOX4.

RESULTS

miR-132 and miR-212 from the same gene cluster are downregulated in human PCa tissues when compared with benign prostatic hyperplasia tissues (both P < 0.05). Functionally, upregulation of miR-132/212 inhibits the migration and invasive capacity of Vcap and Lncap cells by wound-healing and transwell assays, respectively. Notably, overexpression of miR-132/212 could inhibit TGF-β (transforming growth factor-β)-induced EMT in Vcap and Lncap cells at both the mRNA and protein expression levels. SOX4 gene, an important EMT regulator of PCa, was identified as the target of miR-132/212 by bioinformatics tools and luciferase reporter assay. Clinically, miR-132/212 expression levels were adversely correlated with Gleason score (P < 0.001) and SOX4 expression by IHC and RT-qPCR in PCa tissues.

CONCLUSION

Our data suggested that miR-132/212 may act as tumor suppressors in PCa progression through disrupting EMT process by directly targeting SOX4. Prostate 76:1560-1570, 2016. © 2016 Wiley Periodicals, Inc.

Developmental transcription factor NFIB is a putative target of oncofetal miRNAs and is associated with tumour aggressiveness in lung adenocarcinoma

Genes involved in fetal lung development are thought to play crucial roles in the malignant transformation of adult lung cells. Consequently, the study of lung tumour biology in the context of lung development has the potential to reveal key developmentally relevant genes that play critical roles in lung cancer initiation/progression. Here, we describe for the first time a comprehensive characterization of miRNA expression in human fetal lung tissue, with subsequent identification of 37 miRNAs in non-small cell lung cancer (NSCLC) that recapitulate their fetal expression patterns. Nuclear factor I/B (NFIB), a transcription factor essential for lung development, was identified as a potential frequent target for these 'oncofetal' miRNAs. Concordantly, analysis of NFIB expression in multiple NSCLC independent cohorts revealed its recurrent underexpression (in ∼40-70% of tumours). Interrogation of NFIB copy number, methylation, and mutation status revealed that DNA level disruption of this gene is rare, and further supports the notion that oncofetal miRNAs are likely the primary mechanism responsible for NFIB underexpression in NSCLC. Reflecting its functional role in regulating lung differentiation, low expression of NFIB was significantly associated with biologically more aggressive subtypes and, ultimately, poorer survival in lung adenocarcinoma patients. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

MicroRNA expression profiles predict progression and clinical outcome in lung adenocarcinoma

Lung cancer is one of the leading causes of cancer death worldwide. Accumulating evidence has indicated that microRNAs (miRNAs) can be proposed as promising diagnostic and prognostic markers for various cancers. The current study analyzed the miRNA expression profiles of 418 lung adenocarcinoma (LUAD) cases obtained from The Cancer Genome Atlas dataset, with the aim to investigate the relationship of miRNAs with progression and prognosis of LUAD. A total of 185 miRNAs were found to be differentially expressed between LUAD tumor tissues and adjacent normal tissues. Among them, 13, 10, 0, and 10 miRNAs were discovered to be associated with pathologic T, N, M, and Stage, respectively. Interestingly, mir-200 family (mir-200a, mir-200b, and mir-429) was shown to play a critical role in the progression of LUAD. In the multivariate Cox regression analysis, mir-1468 (P=0.009), mir-212 (P=0.026), mir-3653 (P=0.012), and mir-31 (P=0.002) were significantly correlated with recurrence-free survival. With regard to overall survival, mir-551b (P=0.011), mir-3653 (P=0.016), and mir-31 (P=0.001) were proven as independent prognostic markers. In summary, this study identified the cancer-specific miRNAs that may predict the progression and prognosis of LUAD.

MicroRNA-212 suppresses tumor growth of human hepatocellular carcinoma by targeting FOXA1

MicroRNA-212 (miR-212) has been reported to play oncogenic or tumor suppressive role in different human malignancies. Here, we demonstrated that the mean level of miR-212 in hepatocellular carcinoma (HCC) tissues was significantly lower than that in matched tumor-adjacent tissues. Similarly, the expression of miR-212 was obviously reduced in HCC cell lines as compared with a nontransformed hepatic cell line. Ectopic expression of miR-212 inhibited cell viability and proliferation, and induced apoptosis in HepG2 cells. In contrast, down-regulation of miR-212 increased cell viability and proliferation, and suppressed apoptosis in Bel-7402 cells. In vivo studies showed that miR-212 inhibited tumor growth of HCC via suppressing proliferation and inducing apoptosis. Furthermore, we confirmed that Forkhead box protein A1 (FOXA1) was a direct target of miR-212, and it abrogated the function of miR-212 in HCC. Finally, we disclosed that the aberrant expression of miR-212 and FOXA1 was evidently correlated with poor prognostic features of HCC. MiR-212, FOXA1 and their combination were valuable prognostic markers for predicting survival of HCC patients. In conclusion, miR-212 may serve as a prognostic indicator for HCC patients and exerts tumor suppressive role, at least in part, by inhibiting FOXA1.

Aptamer-miRNA-212 Conjugate Sensitizes NSCLC Cells to TRAIL

TNF-related apoptosis-inducing ligand (TRAIL) is a promising antitumor agent for its remarkable ability to selectively induce apoptosis in cancer cells, without affecting the viability of healthy bystander cells. The TRAIL tumor suppressor pathway is deregulated in many human malignancies including lung cancer. In human non-small cell lung cancer (NSCLC) cells, sensitization to TRAIL therapy can be restored by increasing the expression levels of the tumor suppressor microRNA-212 (miR-212) leading to inhibition of the anti-apoptotic protein PED/PEA-15 implicated in treatment resistance. In this study, we exploited a previously described RNA aptamer inhibitor of the tyrosine kinase receptor Axl (GL21.T) expressed on lung cancer cells, as a means to deliver miR-212 into human NSCLC cells expressing Axl. We demonstrate efficient delivery of miR-212 following conjugation of the miR to GL21.T (GL21.T-miR212 chimera). We show that the chimera downregulates PED and restores TRAIL-mediate cytotoxicity in cancer cells. Importantly, treatment of Axl+ lung cancer cells with the chimera resulted in (i) an increase in caspase activation and (ii) a reduction of cell viability in combination with TRAIL therapy. In conclusion, we demonstrate that the GL21.T-miR212 chimera can be employed as an adjuvant to TRAIL therapy for the treatment of lung cancer.

MicroRNA-212 inhibits hepatocellular carcinoma cell proliferation and induces apoptosis by targeting FOXA1

MircroRNA-212 (miR-212) is proposed as a novel tumor-related miRNA and has been found to be significantly deregulated in human cancers. In this study, the miR-212 expression was found to be obviously downregulated in hepatocellular carcinoma (HCC) tissues as compared with adjacent nontumor tissues. Clinical association analysis indicated that low expression of miR-212 was prominently correlated with poor prognostic features of HCC, including high AFP level, large tumor size, high Edmondson-Steiner grading, and advanced tumor-node-metastasis tumor stage. Furthermore, the miR-212 expression was an independent prognostic marker for predicting both 5-year overall survival and disease-free survival of HCC patients. Our in vitro studies showed that upregulation of miR-212 inhibited cell proliferation and induced apoptosis in HepG2 cells. On the contrary, downregulation of miR-212 promoted cell proliferation and suppressed apoptosis in Huh7 cells. Interestingly, we found that upregulation of miR-212 decreased FOXA1 expression in HepG2 cells. Significantly, FOXA1 was identified as a direct target of miR-212 in HCC. FOXA1 was downregulated in HCC tissues as compared with noncancerous tissues. An inverse correlation between FOXA1 and miR-212 expression was observed in HCC tissues. Notably, FOXA1 knockdown inhibited cell proliferation and induced apoptosis in HepG2 cells. In conclusion, miR-212 is a potent prognostic marker and may suppress HCC tumor growth by inhibiting FOXA1 expression.

MicroRNA-148a reduces tumorigenesis and increases TRAIL-induced apoptosis in NSCLC

Nonsmall cell lung cancer (NSCLC) is one of the leading causes of death worldwide. TNF-related apoptosis-inducing ligand (TRAIL) has been shown to induce apoptosis in malignant cells without inducing significant toxicity in normal cells. However, several carcinomas, including lung cancer, remain resistant to TRAIL. MicroRNAs (miRNAs) are small noncoding RNAs of ∼ 24 nt that block mRNA translation and/or negatively regulate its stability. They are often aberrantly expressed in cancer and have been implicated in increasing susceptibility or resistance to TRAIL-induced apoptosis by inhibiting key functional proteins. Here we show that miR-148a is down-regulated in cells with acquired TRAIL-resistance compared with TRAIL-sensitive cells. Enforced expression of miR-148a sensitized cells to TRAIL and reduced lung tumorigenesis in vitro and in vivo through the down-modulation of matrix metalloproteinase 15 (MMP15) and Rho-associated kinase 1 (ROCK1). These findings suggest that miR-148a acts as a tumor suppressor and might have therapeutic application in the treatment of NSCLC.

miR-212/132 downregulates SMAD2 expression to suppress the G1/S phase transition of the cell cycle and the epithelial to mesenchymal transition in cervical cancer cells

MicroRNAs (miRNAs), a class of small noncoding RNAs that regulate target gene expression, play an important role in cancer initiation, progression, and metastasis. However, the role of many miRNAs in cervical cancer is not fully understood. In this study, we found that miR-212 and miR-132 from the same gene cluster are downregulated in human cervical cancer tissues when compared with adjacent noncancerous tissues. The overexpression of miR-212/132 not only led to a delay in the G1/S phase transition and repressed cell proliferation but also resulted in an increase in E-cadherin expression and a decrease in vimentin, suppressing the epithelial to mesenchymal transition and migration and invasion in cervical cancer cells. Subsequently, SMAD2 was identified as a common target of miR-212/132 and was found to be negatively regulated by miR-212/132 at the mRNA and protein levels. Furthermore, SMAD2 silencing led to the same effect on cervical cancer cells as miR-212/132 overexpression. Importantly, SMAD2 overexpression partially reversed the cellular phenotypes induced by miR-212/132 overexpression. In conclusion, our study indicated that miR-212/132 functions as tumor suppressor by targeting SMAD2 in cervical cancer.