Inhibition of microRNA miR-92a induces apoptosis and inhibits cell proliferation in human acute promyelocytic leukemia through modulation of p63 expression

MicroRNAs involved in innate immunity regulation in the sea cucumber: A review

The sea cucumber is one of the most economically significant echinoderms. The immunity against exogenous stimulation of sea cucumber is of great academic and economic importance. MicroRNAs (miRNAs) are a class of short endogenous non-coding RNAs (ncRNAs) that are considered as vital regulators of both innate and adaptive immune responses in most eukaryotes. In sea cucumbers, some miRNAs (such as miR-133, miR-137, and miR-2008, among others) that participate in the regulation of innate immunity have been recently identified and characterized. This review focuses on those known miRNAs and their corresponding target genes that participate in the regulation of the complement system, Toll-like receptor (TLR) pathway, reactive oxygen species (ROS) production and apoptosis pathways in sea cucumbers. Moreover, we cover immune-related miRNA investigations in sea cucumbers that provide insights into developing more miRNA-based biomarkers and therapeutic strategies for sea cucumber diseases.

Retraction Note to: Inhibition of microRNA miR-92a induces apoptosis and inhibits cell proliferation in human acute promyelocytic leukemia through modulation of p63 expression

The Editor-in-Chief has decided to retract this article [1]. The article shows significant overlap with two prior publications by the same authors [2, 3], without providing the due citation and attribution.

Retraction Note to: Inhibition of microRNA miR-92a induces apoptosis and inhibits cell proliferation in human acute promyelocytic leukemia through modulation of p63 expression

The Editor-in-Chief has decided to retract this article [1]. The article shows significant overlap with two prior publications by the same authors [2, 3], without providing the due citation and attribution.

MicroRNAs in cancer cell death pathways: Apoptosis and necroptosis

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

MiR-19a as a prognostic indicator for cancer patients: a meta-analysis

MiR-19a was aberrantly expressed in various types of cancers and was observed to be potentially associated with the prognosis of cancer patients. The present analysis aims to elucidate its precise predictive value in various human malignancies. Online electronic searches of PubMed, Web of Science (WOS), Embase in English and VIP, Wanfang, SinoMed, and the China National Knowledge Infrastructure (CNKI) in Chinese up to September 8, 2018 were conducted. As a result, in overall analysis, a significant association was identified between miR-19a levels and OS (HRs = 2.31, CI: 1.11–4.83). The relation of miR-19a expression to OS was further recognized by fixed model within the studies of sample size less than 150 (HRs = 1.68, CI: 1.35–2.08), NOS scores greater than or equal to 8 (HRs = 1.53, CI: 1.13–2.06) or less than 8 (HRs = 1.89, CI: 1.58–2.27), specimen derived from tumor (HRs = 1.73, CI: 1.42–2.12) or blood (HRs = 1.87, CI: 1.46–2.40) and the patients of osteosarcoma (HRs = 7.17, CI: 5.04–10.21). Sensitivity analyses revealed no significant results. The association between miR-19a expression level and DFS was also found to be significant (HRs = 2.03, CI: 1.13–3.66). Correlations between miR-19a levels and clinicopathological features were examined and revealed that lymph node metastasis was significantly associated with miR-19a expression levels (OR = 0.565, CI: 0.346–0.921). Summarily, the over expression of miR-19a was an underlying risk of poor prognosis in many human malignancies, especially in osteosarcoma. Moreover, elevated miR-19a expression was linked to the potential of lymph node metastasis.

Inhibition of microRNA-92a increases blood vessels and satellite cells in skeletal muscle but does not improve duchenne muscular dystrophy-related phenotype in mdx mice

INTRODUCTION

The vasculature and blood flow in muscle are perturbed in Duchenne muscular dystrophy (DMD) and its mdx mouse model. MicroRNA-92a (miR-92a) is enriched in endothelial cells, especially during ischemic injury.

METHODS

Because antagonizing miR-92a was shown to result in increased proliferation and migration of endothelial cells and recovery from ischemia, we assessed the effects of Antagomir-92a in vitro in muscle stem cell culture and in vivo in mdx mice.

RESULTS

miR-92a was found to be highly expressed in muscle endothelial cells and satellite cells. Treatment with Antagomir-92a increased capillary density and tissue perfusion, which was accompanied by an increase in satellite cells. However, Antagomir-92a-treated mdx mice showed no histological improvement and had worse muscle function. Antagomir-92a suppressed myogenic differentiation in satellite cell culture.

DISCUSSION

AntagomiR-92a improves the vasculature but not the muscle in mdx mice, possibly due to its side effects on satellite cell differentiation. Muscle Nerve 59:594-594, 2019.

MicroRNA in leukemia: Tumor suppressors and oncogenes with prognostic potential

Leukemia is known as a progressive malignant disease, which destroys the blood-forming organs and results in adverse effects on the proliferation and development of leukocytes and their precursors in the blood and bone marrow. There are four main classes of leukemia including acute leukemia, chronic leukemia, myelogenous leukemia, and lymphocytic leukemia. Given that a variety of internal and external factors could be associated with the initiation and progression of different types of leukemia. One of the important factors is epigenetic regulators such as microRNAs (miRNAs) and long noncoding RNAs (ncRNA). MiRNAs are short ncRNAs which act as tumor suppressor (i.e., miR-15, miR-16, let-7, and miR-127) or oncogene (i.e., miR-155, miR-17-92, miR-21, miR-125b, miR-93, miR-143-p3, miR-196b, and miR-223) in leukemia. It has been shown that deregulation of these molecules are associated with the initiation and progression of leukemia. Hence, miRNAs could be used as potential therapeutic candidates in the treatment of patients with leukemia. Moreover, increasing evidence revealed that miRNAs could be used as diagnostic and prognostic biomarkers in monitoring patients in early stages of disease or after received chemotherapy regimen. It seems that identification and development of new miRNAs could pave to the way to the development new therapeutic platforms for patients with leukemia. Here, we summarized various miRNAs as tumor suppressor and oncogene which could be introduced as therapeutic targets in treatment of leukemia.

OncomiR or antioncomiR: Role of miRNAs in Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) is a hematopoietic progenitor/stem cell disorder in which neoplastic myeloblasts are stopped at an immature stage of differentiation and lost the normal ability of proliferation and apoptosis. MicroRNAs (miRNAs) are small noncoding, single-stranded RNA molecules that can mediate the expression of target genes. While miRNAs mean to contribute the developments of normal functions, abnormal expression of miRNAs and regulations on their corresponding targets have often been found in the developments of AML and described in recent years. In leukemia, miRNAs may function as regulatory molecules, acting as oncogenes or tumor suppressors. Overexpression of miRNAs can down-regulate tumor suppressors or other genes involved in cell differentiation, thereby contributing to AML formation. Similarly, miRNAs can down-regulate different proteins with oncogenic activity as tumor suppressors. We herein review the current data on miRNAs, specifically their targets and their biological function based on apoptosis in the development of AML.

MicroRNA-92a antagonism attenuates lipopolysaccharide (LPS)-induced pulmonary inflammation and injury in mice through suppressing the PTEN/AKT/NF-κB signaling pathway

Overwhelming lung inflammation is a key feature of acute lung injury (ALI). MicroRNAs (miRNAs) have been implicated in the regulation diverse cellular processes including the inflammatory response. However, little is known about their functions and molecular involvement in regulating the inflammatory process in ALI. Herein, we established a lipopolysaccharide (LPS)-induced ALI mouse model and used miRNA microarray analysis to investigate and compare the miRNA expression profiles in mouse lung tissues. We found that miR-92a was markedly upregulated in the lung tissues of ALI mice compared with that in normal lung tissues. This upregulation of miR-92a in LPS-induced ALI mice was further confirmed in lung tissues, splenocytes and bronchoalveolar lavage fluid (BALF) by quantitative real-time PCR. Inhibition of miR-92a by injection with antagomir-92a markedly reduced LPS-induced pathological changes associated with lung inflammation, and reduces lung wet/dry ratio (W/D ratio), and Evans blue dye extravasation (an indicator of lung epithelial permeability). Moreover, inhibition of miR-92a ameliorated the inflammatory response by reducing the repression of proinflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 in lung tissues. In addition, we identified that miR-92a inhibited the phosphatase and tensin homolog on chromosome ten (PTEN) by binding to its 3'-UTR in RAW264.7 murine macrophage cells. Western blot analysis demonstrated that inhibition of miR-92a may ameliorate inflammatory response through blocking PTEN/AKT/NF-κB signaling pathway in ALI mice. Collectively, these results have revealed a significant role of miR-92a in the lung inflammatory response associated with ALI in mice, and suggest that miR-92a may have potential as a prognostic indicator and novel therapeutic target for the treatment of ALI in future.

Antiproliferative effect of upregulation of hsa-let-7c-5p in human acute erythroleukemia cells

New achievements in the field of cancer treatment are results of recent advances in molecular medicine and gene therapy. Usage of microRNAs (miRNAs) which are small noncoding RNAs is one of the molecular research lines for the diagnosis and treatment of cancers. miRNAs have an important role in post-transcriptional regulation of the gene expression and are involved in cellular activities such as growth, differentiation, cell death and cancer development. One of the miRNAs that showed downregulation in human acute erythroleukemia is hsa-let-7c-5p. Down-regulation of hsa-let-7c-5p has been reported in in vitro studies of different cancers. In the present study, upregulation of hsa-let-7c-5p is performed in human acute erythroleukemia cell line (KG-1) using miRNA mimic. qRT-PCR, MTT assay, Annexin-V, and propidium iodide staining at different time points after miRNA mimic transfection were accomplished to assess the expression level of hsa-let-7c-5p, cell viability, apoptosis and late apoptosis. In addition, the expression level of PBX2 oncogene, a validated target gene of hsa-let-7c-5p, is evaluated by RT-qPCR to show the effectivity of this approach on erythroleukemia cancer cells. Our results can be used in translational medicine for future investigation in acute erythroleukemia and to approach treatment based on miRNA mimic therapy.

Retracted: MicroRNA-92a promotes tumor growth and suppresses immune function through activation of MAPK/ERK signaling pathway by inhibiting PTEN in mice bearing U14 cervical cancer

Cervical cancer is known as the possible outcome of genital infection, while the molecular mechanisms of initiation, development, and metastasis of cervical cancer have not yet been fully elucidated. Our study aims to investigate the effects of microRNA-92a (miR-92a) on tumor growth and immune function by targeting PTEN via the MAPK/ERK signaling pathway in tumor-bearing mice. C57BL/6 female mice were used for tumor-bearing mouse models and their tumor and adjacent normal tissues were collected, and normal cervical tissues were obtained from normal mice. Serum levels of tumor necrosis factor-α (TNF-α) and soluble interleukin-2 receptor (sIL-2R) were detected by ELISA. The cells were divided into the normal, blank, negative control (NC), miR-92a mimic, miR-92a inhibitor, siRNA-PTEN, and miR-92a inhibitor + siRNA-PTEN groups. Dual-luciferase reporter assay was adopted to determine the relationship between PTEN and miR-92a. Expressions of miR-92a, PTEN, TNF-α, sIL-2R, ERK1, and ERK2 were tested by RT-qPCR and Western blotting. Cell proliferation was detected by cell count kit-8 (CCK-8); cell cycle and apoptosis were detected by flow cytometry. Compared with the normal cervical tissues and adjacent normal tissues, the cervical cancer tissues exhibited increased expressions of miR-92a, p-ERK1/2, and serum levels of TNF-α and sIL-2R while decreased PTEN expression. PTEN was confirmed to be the target gene of miR-92a. As compared with the blank and NC groups, expressions of miR-92a, ERK1 and ERK2 increased, and expressions of PTEN decreased in the miR-92a mimic group. The miR-92a mimic group exhibited increased expression levels of TNF-α and sIL-2R, cell proliferation, and cell number in S phase but decreased cell apoptosis, and cell number in G0/G1 phase, while the miR-92a inhibitor group followed opposite trends. miR-92a promotes tumor growth and suppresses immune function by inhibiting PTEN via activation of the MAPK/ERK signaling pathway in mice bearing U14 cervical cancer.

Signal pathways, diseases, and functions associated with the miR-19a/92a cluster and the use of berberine to modulate the expression of this cluster in multiple myeloma cells

BACKGROUND

Berberine downregulated miR-19a/92a cluster expression in multiple myeloma (MM) cells.

METHODS

The cell viability of MM cells after berberine treatment was measured by CCK8 assay. qRT-PCR assay validated miR-19a/92a expression in multiple myeloma cells. TAM database analyzed miR-19a/92a-associated disease. miREnvironment database revealed that effects of environmental factors on the miR-19a/92a cluster. By targeting the seed region in the miRNA, the role of t-anti-miR-19a/92a cluster was evaluated by cell proliferation, migration, and colony formation.

RESULTS

Berberine inhibited the cell viability of MM cells and downregulated the expression of miR-19a/92a. Seven kinds of hematological malignancies are closely associated with miR-19a/92a expression. By targeting the seed region of the miRNA, t-anti-miR-19a/92a significantly inhibits multiple myeloma cell proliferation, migration, and colony formation.

CONCLUSION

Our findings may exhibit that miR-19a/92a cluster is a therapeutic target for MM and provide new mechanistic insight into the anti-MM effects of certain compounds in traditional Chinese herbal medicines.

Exosomal miRNAs as novel cancer biomarkers: Challenges and opportunities

A biomarker with high specificity and sensitivity, is a basic requirement for non-invasive cancer diagnosis. Exosomes are a type of lipid bilayer extracellular vesicles (EVs), containing different components, including proteins, lipids, DNA, messenger RNA (mRNA), and non-coding RNAs. Increasing evidence indicates that nucleic acids are protected by exosome lipid membrane. These vesicles are almost released from all cell types, into biological fluids. In cancer, the expression of microRNAs (miRNAs), located in the tumor cell-derived exosomes, is deregulated and it could be led to metastasis and therapy resistance. Due to the presence of exosomes in various body fluids and the stability of miRNAs in exosomes, exosomal miRNAs can provide a new class of biomarkers for early and minimally invasive cancer diagnosis. In this article, we review the miRNAs and their roles in cancer. Furthermore, we explain the different types of EVs, especially exosomes, and their functional roles in cancer. At the end, we discuss about the importance of exosomal miRNAs for cancer diagnosis. As well as, we briefly summarize the exosome isolation techniques and obstacles, limiting the clinical applications of exosomal miRNAs.

miR-218 inhibits acute promyelocytic leukemia cell growth by targeting BMI-1

Acute promyelocytic leukemia (APL) is a subtype of acute myelocytic leukemia. Previous studies have reported a number of functions and therapeutic roles of microRNAs (miRs) in APL, and have suggested that miR-218 acts as a tumor suppressor in a number of types of human cancer; however, its role in APL remains unclear. In the present study, the expression of miR-218 and its effects on the viability and proliferation of HL-60 cells was investigated. Reverse transcription-quantitative polymerase chain reaction analysis demonstrated that miR-218 was frequently downregulated in APL marrow tissues compared with normal marrow tissues. Overexpression of miR-218 significantly inhibited cell proliferation, arrested the cell cycle in the G₀/G₁ phase and induced apoptosis. In addition, B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) mRNA expression was negatively associated with miR-218 expression; BMI-1 mRNA and protein expression were downregulated following transfection with miR-218 mimic. These results indicate that miR-218 functions as tumor suppressor in APL, and the miR-218/BMI-1 signaling axis may be a potential novel diagnostic marker and therapeutic target for the treatment of APL.

miR-92a regulates coelomocytes apoptosis in sea cucumber Apostichopus japonicus via targeting Aj14-3-3ζ in vivo

miR-92a, a well-documented oncogene, was previously found to be differentially expressed in diseased sea cucumber Apostichopus japonicus by high-throughput sequencing. In this study, we identified Aj14-3-3ζ as a novel target of miR-92a in this species and investigated their regulatory roles in vivo. The negative expression profiles between miR-92a and Aj14-3-3ζ protein were detected in both LPS-exposed primary coelomocytes and Vibrio splendidus-challenged sea cucumbers. Over-expression of miR-92a by injection of miR-92a agomir significantly depressed the mRNA and protein expression of Aj14-3-3ζ and promoted coelomocytes apoptosis with 5.04-fold increase in vivo, which was consistent with those from siRNA-mediated Aj14-3-3ζ knockdown assay. In contrast, miR-92a antagomir significantly elevated the mRNA and protein expression of Aj14-3-3ζ and decreased coelomocytes apoptosis. Taken together, our result confirmed that miR-92a is involved in apoptotic signaling pathway regulation perhaps via targeting Aj14-3-3ζ in sea cucumbers, which will enhance our understanding of miR-92a regulatory roles in sea cucumber pathogenesis.

Current Status and Perspectives Regarding LNA-Anti-miR Oligonucleotides and microRNA miR-21 Inhibitors as a Potential Therapeutic Option in Treatment of Colorectal Cancer

Colorectal cancer (CRC) is among the leading causes of cancer-related death, principally due to its metastatic spread and multifactorial chemoresistance. The therapeutic failure can also be explained by inter- or intra-tumor genetic heterogeneity and tumor stromal content. Thus, the identification of novel prognostic biomarkers and therapeutic options are warranted in the management of CRC patients. There are data showing that microRNA-21 is elevated in different types of cancer, particularly colon adenocarcinoma and that this is association with a poor prognosis. This suggests that microRNA-21 may be of value as a potential therapeutic target. Furthermore, locked nucleic acid (LNA)-modified oligonucleotides have recently emerged as a therapeutic option for targeting dysregulated miRNAs in cancer therapy, through antisense-based gene silencing. Further work is required to identify innovative anticancer drugs that improve the current therapy either through novel combinatorial approaches or with better efficacy than conventional drugs. We aimed to provide an overview of the preclinical and clinical studies targeting key dysregulated signaling pathways in CRC as well as the therapeutic application of LNA-modified oligonucleotides, and miR inhibitors in the treatment of CRC patients. J. Cell. Biochem. 118: 4129-4140, 2017. © 2017 Wiley Periodicals, Inc.

Effective Integration of Targeted Tumor Imaging and Therapy Using Functionalized InP QDs with VEGFR2 Monoclonal Antibody and miR-92a Inhibitor

Rapid diagnosis and targeted drug treatment require agents that possess multiple functions. Nanomaterials that facilitate optical imaging and direct drug delivery have shown great promise for effective cancer treatment. In this study, we first modified near-infrared fluorescent indium phosphide quantum dots (InP QDs) with a vascular endothelial growth factor receptor 2 (VEGFR2) monoclonal antibody to afford targeted drug delivery function. Then, a miR-92a inhibitor, an antisense microRNA that enhances the expression of tumor suppressor p63, was attached to the VEGFR2-InP QDs via electrostatic interactions. The functionalized InP nanocomposite (IMAN) selectively targets tumor sites and allows for infrared imaging in vivo. We further explored the mechanism of this active targeting. The IMAN was endocytosed and delivered in the form of microvesicles via VEGFR2-CD63 signaling. Moreover, the IMAN induced apoptosis of human myelogenous leukemia cells through the p63 pathway in vitro and in vivo. These results indicate that the IMAN may provide a new and promising chemotherapy strategy against cancer cells, particularly by its active targeting function and utility in noninvasive three-dimensional tumor imaging.

Inhibition of microRNA-21 via locked nucleic acid-anti-miR suppressed metastatic features of colorectal cancer cells through modulation of programmed cell death 4

Colorectal cancer is among the most lethal of malignancies, due to its propensity to metastatic spread and multifactorial-chemoresistance. The latter property supports the need to identify novel therapeutic approaches for the treatment of colorectal cancer. MicroRNAs are endogenous non-coding small RNA molecules that function as post-transcriptional regulators of gene expression. Recently, programmed cell death 4 has been identified as a protein that increases during apoptosis. This gene is among the potential targets of miR-21 (OncomiR). Locked nucleic acid-modified oligonucleotides have recently emerged as a potential therapeutic option for targeting microRNAs. The aim of this study was to explore the functional role of locked nucleic acid-anti-miR-21 in the LS174T cell line in vitro and in vivo models. LS174T cells were treated with locked nucleic acid-anti-miR-21 for 24, 48, and 72 h in vitro. The expression of miR-21 and PDCD4 at messenger RNA (mRNA) level was evaluated by quantitative real-time polymerase chain reaction, while the protein level of PDCD4 was determined by Western blotting. Cell migratory behavior and the cluster-forming ability of cells were assessed before and after therapy. The disseminated tumor cells were assessed in the chick chorioallantoic membrane model by Alu quantitative polymerase chain reaction. Locked nucleic acid-anti-miR-21 was transfected successfully into the LS174T cells and inhibited the expression of miR-21. Locked nucleic acid-anti-miR-21 inhibited the migration and the number of cells forming clusters. Moreover, we found that locked nucleic acid-anti-miR-21 transfection was associated with a significant reduction in metastatic properties as assessed by the in ovo model. Our findings demonstrated the novel therapeutic potential of locked nucleic acid-anti-miR-21 in colon adenocarcinoma with high miR-21 expression.

Inducing cell proliferative prevention in human acute promyelocytic leukemia by miR-182 inhibition through modulation of CASP9 expression

MicroRNAs (miRNAs) are one class of endogenous non-coding RNAs that involved in post-transcriptional regulation of the gene. MiRNAs through interaction with messenger RNA (mRNA) involved in several biological processes such as cell cycle, differentiation, growth, metabolism, aging and apoptosis. MiRNAs may act as an oncogene or a tumor suppressor via up or down regulation in cancerous cells. MiR-182 located in a miR-183/-96/-182 cluster, this is the highly conserved cluster to have an important role in cancer development and tumorigenesis. Abnormal expression of miR-182 in a variety of human cancers has reported. Oncogenic features of miR-182 confirmed through negative regulation of various tumor suppressor genes. In this study, miR-182 inhibition in acute promyelocytic leukemia (APL) cell line (HL60) was performed by locked nucleic acid (LNA) anti-miR. MTT assay in three-time points 24, 48 and 72h after LNA-anti-miR-182 transfection was performed. Our study demonstrated inhibition of miR-182 can expansively decrease cell proliferation of APL cells. The Western blotting analysis presents that CASP9 expression associated with inhibition of miR-182. CASP9 protein has an important role in the mitochondrial cell death pathway as the initiator of apoptosis. These results can offer a way for inhibition of APL cells proliferates and produce translational medicine based on microgenomics and antisense therapy.

The role of exosomes and miRNAs in drug-resistance of cancer cells

Chemotherapy, one of the principal approaches for cancer patients, plays a crucial role in controlling tumor progression. Clinically, tumors reveal a satisfactory response following the first exposure to the chemotherapeutic drugs in treatment. However, most tumors sooner or later become resistant to even chemically unrelated anticancer agents after repeated treatment. The reduced drug accumulation in tumor cells is considered one of the significant mechanisms by decreasing drug permeability and/or increasing active efflux (pumping out) of the drugs across the cell membrane. The mechanisms of treatment failure of chemotherapeutic drugs have been investigated, including drug efflux, which is mediated by extracellular vesicles (EVs). Exosomes, a subset of EVs with a size range of 40-150 nm and a lipid bilayer membrane, can be released by all cell types. They mediate specific cell-to-cell interactions and activate signaling pathways in cells they either fuse with or interact with, including cancer cells. Exosomal RNAs are heterogeneous in size but enriched in small RNAs, such as miRNAs. In the primary tumor microenvironment, cancer-secreted exosomes and miRNAs can be internalized by other cell types. MiRNAs loaded in these exosomes might be transferred to recipient niche cells to exert genome-wide regulation of gene expression. How exosomal miRNAs contribute to the development of drug resistance in the context of the tumor microenvironment has not been fully described. In this review, we will highlight recent studies regarding EV-mediated microRNA delivery in formatting drug resistance. We also suggest the use of EVs as an advancing method in antiresistance treatment.

Apoptosis-inducing and antiproliferative effect by inhibition of miR-182-5p through the regulation of CASP9 expression in human breast cancer

Recent advances in molecular medicine and gene therapy have offered new effective achievements in the treatment of cancers. One of the molecular research lines for the diagnosis and treatment of cancer is the use of microRNAs (miRNAs), which are single-stranded noncoding RNAs. miRNAs are involved in the post-transcriptional regulation of gene expression and have a role in the growth, differentiation, cell death and cancer development. One of the miRNAs that showed upregulation in breast cancer is miR-182-5p. Oncogenic features of miR-182-5p in some cancers were confirmed. In the present study, blockage of miR-182-5p was performed in human breast cancer cell line (MCF-7) using locked nucleic acid (LNA)-anti-miR. MTT (3-[4,5 dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay and annexin/propidium iodide staining at different time points after LNA-anti-miR-182-5p transfection were accomplished. Our results showed that miR-182-5p inhibition can reduce the viability of MCF-7 cells because of apoptosis induction, probably through the upregulation of CASP9. A western blot analysis revealed that the expression of CASP9 protein is associated with miR-182-5p inhibition. The CASP9 protein acts as an initiator caspase of apoptosis in the mitochondrial cell death pathway. Our results can be used in translational medicine for future investigation in breast cancer and approach treatment based on antisense therapy.

ΔNp63α and microRNAs: leveraging the epithelial-mesenchymal transition

The epithelial-mesenchymal transition (EMT) is a cellular reprogramming mechanism that is an underlying cause of cancer metastasis. Recent investigations have uncovered an intricate network of regulation involving the TGFβ, Wnt, and Notch signaling pathways and small regulatory RNA species called microRNAs (miRNAs). The activity of a transcription factor vital to the maintenance of epithelial stemness, ΔNp63α, has been shown to modulate the activity of these EMT pathways to either repress or promote EMT. Furthermore, ΔNp63α is a known regulator of miRNA, including those directly involved in EMT. This review discusses the evidence of ΔNp63α as a master regulator of EMT components and miRNA, highlighting the need for a deeper understanding of its role in EMT. This expanded knowledge may provide a basis for new developments in the diagnosis and treatment of metastatic cancer.

Elevated expression of microRNA-19a predicts a poor prognosis in patients with osteosarcoma

MicroRNA (miR)-19a, a member of the miR-17-92 cluster, functions as an oncomiRNA in multiple kinds of cancers. However, its involvement in human osteosarcomas remains unclear. In this study, to analyze the expression pattern of miR-19a and to investigate its clinical implication in human osteosarcomas, quantitative reverse-transcription polymerase chain reaction was performed to detect expression levels of miR-19a in 166 self-pairs of osteosarcoma and noncancerous bone tissues. Associations between miR-19a expression and various clinicopathological parameters and patients' prognosis of osteosarcomas were further evaluated. As a results, miR-19a expression in osteosarcoma tissues was significantly higher than that in corresponding noncancerous bone tissues (P<0.001). Osteosarcoma patients with high miR-19a expression more frequently had large tumor size (P=0.03), advanced clinical stage (P=0.01), positive distant metastasis (P=0.008) and poor response to chemotherapy (P=0.01) than those with low miR-19a expression. Additionally, kaplan-Meier analysis showed that both overall and disease-free survivals of osteosarcoma patients with high miR-19a expression were shorter than those with low miR-19a expression (both P<0.001). Further multivariate analysis identified miR-19a expression as an independent prognostic factor for both overall (P=0.001) and disease-free (P=0.006) survivals. In conclusion, the aberrant expression of miR-19a may play a crucial role in development and progression of human osteosarcomas. MiR-19a may act as a novel prognostic marker for patients with this malignancy.

Resveratrol Inhibits Proliferation, Invasion, and Epithelial-Mesenchymal Transition by Increasing miR-200c Expression in HCT-116 Colorectal Cancer Cells

OBJECTIVE

colorectal cancer (CRC) is one of the most common malignancies, associated with high rates of relapse. A notable challenge in treatment is low response rate to current therapies for advanced CRC. The miR-200c plays an essential role in tumor suppression by inhibiting epithelial-mesenchymal transition (EMT). Resveratrol, a natural compound found in red wine, reveals anti-cancer properties in several types of cancers such as CRC. The aim of current study was to evaluate the effects of resveratrol on proliferation, apoptosis, and invasion of HCT-116 cells and also expression of EMT-related genes in presences or absence of miR-200c.

METHODS

the effect of resveratrol on viability was examined by MTT assay. LNA-anti-miR-200c transfection of HCT-116 cells was carried out in a time dependent manner. Then, the expression of miR-200c and EMT-related genes were quantified by qRT-PCR. Further, expression of EMT-related proteins, apoptosis, and invasion were analyzed by Western blot, Annexin V/PI staining and scratch test, respectively.

RESULTS

resveratrol could significantly inhibit viability of HCT-116 cells. LNA-anti-miR-200c suppressed the endogenous miR-200c in transfected cells compared with the control. qRT-PCR and Western blot analysis of LNA-anti-miR-200c transfected cells revealed a considerable increase in vimentin and ZEB-1 expression, with a concomitant reduction in E-cadherin expression level. Migration of HCT-116 cells increased, and apoptosis significantly reduced in transfected cells. While, resveratrol could entirely reverse these changes by modulation of miR-200c expression.

CONCLUSION

our findings revealed a major role of resveratrol in apoptosis, invasion, and switching of EMT to MET phenotype through upregulation of miR-200c in CRC. J. Cell. Biochem. 118: 1547-1555, 2017. © 2016 Wiley Periodicals, Inc.

From conventional therapy toward microRNA-based therapy in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a hematopoietic malignancy that is known with its special cytogenetic feature. Several studies have surveyed expression signature of microRNAs (miRNAs) in APL patients, especially patients who are treated with conventional therapy of this disease. Using miRNAs as diagnostic or prognostic biomarkers in various cancers has been widely studied. Currently, most studies are focusing on exploiting miRNAs as therapeutic tools, and promising progress has been achieved in this field. Recently, studies in the field of miRNA-based therapy in APL have been started.

Locked nucleic acid anti-miR-21 inhibits cell growth and invasive behaviors of a colorectal adenocarcinoma cell line: LNA-anti-miR as a novel approach

Colorectal cancer (CRC) is the third leading cause of cancer-related death and has an extremely poor prognosis. Dysregulation of microRNAs (miRNAs) has been shown to be involved in the pathogenesis and progression of many malignancies. Recent data suggest that microRNA-21 (miR-21) is significantly elevated in different types of cancer, especially colon adenocarcinoma. Against this background, locked nucleic acid (LNA)-modified oligonucleotides have recently been suggested as a novel approach for targeting miRNAs as antisense-based gene silencing. The aim of the current study was to explore the functional role of LNA-anti-miR-21 in a colon adenocarcinoma LS174T cell line. LS174T cells were transfected with LNA-anti-miR-21 for 24, 48 and 72 h. Quantitative real-time reverse transcriptase-PCR (qRT-PCR) was performed to assess miR-21 expression by LNA-anti-miR-21. The viability of the cells was evaluated by MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) assay and Annexin V/propidium iodide staining assay was used to detect apoptosis. Moreover, invasive behavior of the cells was evaluated before and after therapy by transwell assay. LNA-anti-miR-21 was successfully transfected in human LS174T cells and suppressed the endogenous miR-21. LNA-anti-miR-21 inhibited the cells' growth followed by induction of apoptosis. LNA-anti-miR-21 (50 pmol/μl) reduced the invasive behaviors of LS174T cells after 24 h, compared with untreated cells and scrambled LNA-transfected cells. However, this effect was more pronounced after 72 h. Our findings suggest the therapeutic potential of LNA-anti-miR-21 in a colon adenocarcinoma for targeting miR-21 expression. Further studies are warranted to investigate the molecular mechanisms underlying this novel inhibitor in colorectal cancer to establish its potential value for treatment of CRC patients with high miR-21 expression.

Inhibition of MicroRNA miR-222 with LNA Inhibitor Can Reduce Cell Proliferation in B Chronic Lymphoblastic Leukemia

MicroRNAs (miRNAs) are small regulatory molecules that negatively regulate gene expression by base-pairing with their target mRNAs. miRNAs have contribute significantly to cancer biology and recent studies have demonstrated the oncogenic or tumor-suppressing role in cancer cells. In many tumors up-regulation miRNAs has been reported especially miR-222 has been shown to be up-regulated in B chronic lymphocytic leukemia (B-CLL). In this study we assessed the effected inhibition of miR-222 in cell viability of B-CLL. We performed inhibition of mir-222 in B-CLL cell line (183-E95) using locked nucleic acid (LNA) antagomir. At different time points after LNA-anti-mir-222 transfection, miR-222 quantitation and cell viability were assessed by qRT-real time polymerase chain reaction and MTT assays. The data were analyzed by independent t test and one way ANOVA. Down-regulation of miR-222 in B-CLL cell line (183-E95) with LNA antagomir decreased cell viability in B-CLL. Cell viability gradually decreased over time as the viability of LNA-anti-mir transfected cells was <47 % of untreated cells at 72 h post-transfection. The difference in cell viability between LNA-anti-miR and control groups was statistically significant (p < 0.042). Based on our findings, the inhibition of miR-222 speculate represent a potential novel therapeutic approach for treatment of B-CLL.

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

MicroRNAs (miRNAs) are a type of small noncoding RNAs that have a vital role in basic biological processes such as cellular growth, division and apoptosis. A change in the expression of miRNAs can induce many diseases. Recently, the role of miRNA in some of the cancers as a tumor suppressor and oncogene has been recognized. Several studies have proved that miR-92a-3p acts as an oncogene in colorectal cancer (CRC). We studied CRC by inhibiting miR-92a-3p in SW48 cells (human colorectal cancer cell line) that were transfected with locked nucleic acid (LNA). At different times, the expression level of miR-92a-3p, cell vitality, apoptosis and necrosis were studied by qRT-PCR, MTT, Annexin-V and propidiumiodide. Our results showed that the expression of miR-92a-3p and proliferation of SW48 cells were decreased, and also a high percentage of SW48 cells were exposed to apoptosis and necrosis (P⩽0.005). Our study showed that the inhibition of miR-92a-3p with LNA inhibited cell proliferation and induced apoptosis and necrosis in CRC.

Onco-microRNA miR-130b promoting cell growth in children APL by targeting PTEN

OBJECTIVE

To study the expression of microRNA-130b (miR-130b) in children acute promyelocytic leukemia (APL) and its role for regulating PTEN expression.

METHODS

A total of 50 children APL marrow tissues and 15 normal marrow tissues between January and December in 2012 were collected into our study. The expression of miR-130b in APL and normal marrow tissues were detected by quantitative real-time polymerase chain reaction. MiR-130b inhibitor was transfected into HL-60 cells. Cell Counting Kit-8 assay and flow cytometry were used to measure cell proliferation and apoptosis, respectively. The expression of PTEN, a potential target of miR-130b, and its downstream genes, Bcl-2 and Bax, in transformed cells were detected by quantitative real-time polymerase chain reaction and western-blot.

RESULTS

The expression of miR-130b was significantly higher in children APL marrow tissues than in normal marrow tissues (P < 0.05). Down-regulation of miR-130b could significantly suppress cell proliferation and induce apoptosis in HL-60 cells (P < 0.05). PTEN expression was upregulated when miR-130b was knocking-down (P < 0.05). As downstream genes of PTEN, the expression of Bcl-2 and Bax were regulated as well.

CONCLUSIONS

MiR-130b is overexpressed in children APL marrow tissues and associated with cell growth. MiR-130b may promote children APL progression by inducing cell proliferation and inhibiting apoptosis.

Blockage of miR-92a-3p with locked nucleic acid induces apoptosis and prevents cell proliferation in human acute megakaryoblastic leukemia

MicroRNAs (miRNAs) are non-coding RNAs involved in post-transcriptional regulation of gene expression. In many cancers, up- or downregulation of different miRNAs is reported. In acute myeloid leukemia, upregulation of miR-92a-3p was reported in human in vitro studies. We performed blockage of miR-29a-3p in human acute megakaryoblastic leukemia cell line (M-07e) by using locked nucleic acid (LNA) and cell proliferation; apoptosis and necrosis were assessed. At different time points after LNA-anti-miR92a-3p transfection, miR-92a-3p quantitation was assessed by qRT-real-time PCR, MTT assay and annexin/propidium iodide staining were performed. The data were processed using the ANOVA test. At all three time points, the expression of miR-92a-3p was lower in the LNA-anti-miR group compared with the control groups. Cell viability between LNA-Anti-miR and the control group was statistically significant. Blockage of miR-92a-3p was associated with increment of the ratio of apoptotic cells in the LNA-anti-miR group was higher than the other group. The ratio of necrotic cells in the LNA-antimiR group was higher than the other groups. These assessments indicate that miR-92a-3p blockage can decrease the viability of M-07e cells, which is mainly due to induction of apoptosis and necrosis. Our findings could open up a path to a miRNA based therapeutic approach for treatment of acute megakaryoblastic leukemia.

Presence and function of microRNA-92a in chondrogenic ATDC5 and adipose-derived mesenchymal stem cells

The aim of the present study was to investigate the presence and biological function of microRNA-92a (miR-92a) in chondrogenesis and cartilage degeneration. Human adipose-derived mesenchymal stem cells (hADSCs) in micromass and chondrocyte-like ATDC5 cells were induced to chondrogenesis, and primary human/mouse chondrocytes (PHCs/PMCs) and chondrogenic ATDC5 cells were stimulated with interleukin-1β (IL-1β). An miR-92a mimic/inhibitor was transfected into the ATDC5 cells using lipofectamine 2000. Gene expression was analyzed using reverse transcription-quantitative polymerase chain reaction. Alcian blue was used to stain the cartilage nodules and chondrogenic micromass. The potential target genes, signaling pathways and functions of miR-92a were examined using miRanda, miRDB, CLIP-Seq, TargetScan and Kyoto Encyclopedia of Genes and Genomes. The expression of miR-92a was elevated in the chondrogenic ATDC5 cells and hADSCs, and also in the IL-1β-induced ATDC5 cells, PMCs and PHCs. Forced expression of miR-92a enhanced the expression levels of col9a2 and aggrecan. A total of 279 genes were predicted as potential target genes of miR-92a. The phosphoinositide 3-kinase/PI3K)-Akt, ErbB and focal adhesion kinase pathways, extracellular matrix (ECM)-receptor interaction and the mammalian target of rapamycin (mTOR) signaling pathway were suggested to mediate the effects of miR-92a on chondrogenesis and cartilage degeneration. These results demonstrated that miR-92a was involved in chondrogenesis and the chondrocyte response induced by IL-1β. miR-92a positively contributed to the expression of col9a2 and of aggrecan.

A molecular model for neurodevelopmental disorders

Genes implicated in neurodevelopmental disorders (NDDs) important in cognition and behavior may have convergent function and several cellular pathways have been implicated, including protein translational control, chromatin modification, and synapse assembly and maintenance. Here, we test the convergent effects of methyl-CpG binding domain 5 (MBD5) and special AT-rich binding protein 2 (SATB2) reduced dosage in human neural stem cells (NSCs), two genes implicated in 2q23.1 and 2q33.1 deletion syndromes, respectively, to develop a generalized model for NDDs. We used short hairpin RNA stably incorporated into healthy neural stem cells to supress MBD5 and SATB2 expression, and massively parallel RNA sequencing, DNA methylation sequencing and microRNA arrays to test the hypothesis that a primary etiology of NDDs is the disruption of the balance of NSC proliferation and differentiation. We show that reduced dosage of either gene leads to significant overlap of gene-expression patterns, microRNA patterns and DNA methylation states with control NSCs in a differentiating state, suggesting that a unifying feature of 2q23.1 and 2q33.1 deletion syndrome may be a lack of regulation between proliferation and differentiation in NSCs, as we observed previously for TCF4 and EHMT1 suppression following a similar experimental paradigm. We propose a model of NDDs whereby the balance of NSC proliferation and differentiation is affected, but where the molecules that drive this effect are largely specific to disease-causing genetic variation. NDDs are diverse, complex and unique, but the optimal balance of factors that determine when and where neural stem cells differentiate may be a major feature underlying the diverse phenotypic spectrum of NDDs.

Phenotypic characterization of miR-92a-/- mice reveals an important function of miR-92a in skeletal development

MicroRNAs (miRNAs, miRs) emerged as key regulators of gene expression. Germline hemizygous deletion of the gene that encodes the miR-17∼92 miRNA cluster was associated with microcephaly, short stature and digital abnormalities in humans. Mice deficient for the miR-17∼92 cluster phenocopy several features such as growth and skeletal development defects and exhibit impaired B cell development. However, the individual contribution of miR-17∼92 cluster members to this phenotype is unknown. Here we show that germline deletion of miR-92a in mice is not affecting heart development and does not reduce circulating or bone marrow-derived hematopoietic cells, but induces skeletal defects. MiR-92a^−/− mice are born at a reduced Mendelian ratio, but surviving mice are viable and fertile. However, body weight of miR-92a^−/− mice was reduced during embryonic and postnatal development and adulthood. A significantly reduced body and skull length was observed in miR-92a^−/− mice compared to wild type littermates. µCT analysis revealed that the length of the 5^th mesophalanx to 5^th metacarpal bone of the forelimbs was significantly reduced, but bones of the hindlimbs were not altered. Bone density was not affected. These findings demonstrate that deletion of miR-92a is sufficient to induce a developmental skeletal defect.

MicroRNA-92a inhibition attenuates hypoxia/reoxygenation-induced myocardiocyte apoptosis by targeting Smad7

Background

MicroRNAs (miRNAs) regulate a lot of physiological and pathological processes, including myocardial ischemia/reperfusion. Recent studies reported that knockdown of miR-92a could attenuate ischemia/reperfusion-induced myocardial injury. In the present study, we examined the potential anti-apoptotic effects of miR-92a in a rat myocardiocyte cell line, and the possible role of Smad7 in such actions.

Methodology and Results

In a preliminary bioinformatic analysis, we identified SMAD family member 7 (Smad7) as a potential target for miR-92a. A luciferase reporter assay indeed demonstrated that miR-92a could inhibit Smad7 expression. Myocardial ischemia/reperfusion was simulated in rat H9c2 cells with 24-h hypoxia followed by 12-h reoxygenation. Prior to hypoxia/reoxygenation, cells were transfected by miR-92a inhibitor. In some experiments, cells were co-transfected with siRNA-Smad7. The miR-92a inhibitor dramatically reduced the release of lactate dehydrogenase and malonaldehyde, and attenuated cardiomyocyte apoptosis. The miR-92a inhibitor increased SMAD7 protein level and decreased nuclear NF-κB p65 protein. Effects of the miR-92a inhibitor were attenuated by co-transfection with siRNA-Smad7.

Conclusion

Inhibiting miR-92a can attenuate myocardiocyte apoptosis induced by hypoxia/reoxygenation by targeting Smad7.