Functional studies of miR-130a on the inhibitory pathways of apoptosis in patients with chronic myeloid leukemia

Therapeutic advancements in targeting BCL-2 family proteins by epigenetic regulators, natural, and synthetic agents in cancer

Cancer is amongst the deadliest and most disruptive disorders, having a much higher death rate than other diseases worldwide. Human cancer rates continue to rise, thereby posing the most significant concerns for medical health professionals. In the last two decades, researchers have gone past several milestones in tackling cancer while gaining insight into the role of apoptosis in cancer or targeting various biomarker tools for prognosis and diagnosis. Apoptosis which is still a topic full of complexities, can be controlled considerably by B-cell lymphoma 2 (BCL-2) and its family members. Therefore, targeting proteins of this family to prevent tumorigenesis, is essential to focus on the pharmacological features of the anti-apoptotic and pro-apoptotic members, which will help to develop and manage this disorder. This review deals with the advancements of various epigenetic regulators to target BCL-2 family proteins, including the mechanism of several microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Similarly, a rise in natural and synthetic molecules' research over the last two decades has allowed us to acquire insights into understanding and managing the transcriptional alterations that have led to apoptosis and treating various neoplastic diseases. Furthermore, several inhibitors targeting anti-apoptotic proteins and inducers or activators targeting pro-apoptotic proteins in preclinical and clinical stages have been summarized. Overall, agonistic and antagonistic mechanisms of BCL-2 family proteins conciliated by epigenetic regulators, natural and synthetic agents have proven to be an excellent choice in developing cancer therapeutics.

Analysis of microRNAs in Exosomes of Breast Cancer Patients in Search of Molecular Prognostic Factors in Brain Metastases

Brain metastases are the most severe tumorous spread during breast cancer disease. They are associated with a limited quality of life and a very poor overall survival. A subtype of extracellular vesicles, exosomes, are sequestered by all kinds of cells, including tumor cells, and play a role in cell-cell communication. Exosomes contain, among others, microRNAs (miRs). Exosomes can be taken up by other cells in the body, and their active molecules can affect the cellular process in target cells. Tumor-secreted exosomes can affect the integrity of the blood-brain barrier (BBB) and have an impact on brain metastases forming. Serum samples from healthy donors, breast cancer patients with primary tumors, or with brain, bone, or visceral metastases were used to isolate exosomes and exosomal miRs. Exosomes expressed exosomal markers CD63 and CD9, and their amount did not vary significantly between groups, as shown by Western blot and ELISA. The selected 48 miRs were detected using real-time PCR. Area under the receiver-operating characteristic curve (AUC) was used to evaluate the diagnostic accuracy. We identified two miRs with the potential to serve as prognostic markers for brain metastases. Hsa-miR-576-3p was significantly upregulated, and hsa-miR-130a-3p was significantly downregulated in exosomes from breast cancer patients with cerebral metastases with AUC: 0.705 and 0.699, respectively. Furthermore, correlation of miR levels with tumor markers revealed that hsa-miR-340-5p levels were significantly correlated with the percentage of Ki67-positive tumor cells, while hsa-miR-342-3p levels were inversely correlated with tumor staging. Analysis of the expression levels of miRs in serum exosomes from breast cancer patients has the potential to identify new, non-invasive, blood-borne prognostic molecular markers to predict the potential for brain metastasis in breast cancer. Additional functional analyzes and careful validation of the identified markers are required before their potential future diagnostic use.

A Systematic Review of Candidate miRNAs, Its Targeted Genes and Pathways in Chronic Myeloid Leukemia-An Integrated Bioinformatical Analysis

Chronic myeloid leukaemia is blood cancer due to a reciprocal translocation, resulting in a BCR-ABL1 oncogene. Although tyrosine kinase inhibitors have been successfully used to treat CML, there are still cases of resistance. The resistance occurred mainly due to the mutation in the tyrosine kinase domain of the BCR-ABL1 gene. However, there are still many cases with unknown causes of resistance as the etiopathology of CML are not fully understood. Thus, it is crucial to figure out the complete pathogenesis of CML, and miRNA can be one of the essential pathogeneses. The objective of this study was to systematically review the literature on miRNAs that were differentially expressed in CML cases. Their target genes and downstream genes were also explored. An electronic search was performed via PubMed, Scopus, EBSCOhost MEDLINE, and Science Direct. The following MeSH (Medical Subject Heading) terms were used: chronic myeloid leukaemia, genes and microRNAs in the title or abstract. From 806 studies retrieved from the search, only clinical studies with in-vitro experimental evidence on the target genes of the studied miRNAs in CML cells were included. Two independent reviewers independently scrutinised the titles and abstracts before examining the eligibility of studies that met the inclusion criteria. Study design, sample size, sampling type, and the molecular method used were identified for each study. The pooled miRNAs were analysed using DIANA tools, and target genes were analysed with DAVID, STRING and Cytoscape MCODE. Fourteen original research articles on miRNAs in CML were included, 26 validated downstream genes and 187 predicted target genes were analysed and clustered into 7 clusters. Through GO analysis, miRNAs’ target genes were localised throughout the cells, including the extracellular region, cytosol, and nucleus. Those genes are involved in various pathways that regulate genomic instability, proliferation, apoptosis, cell cycle, differentiation, and migration of CML cells.

Downregulation of miR-142a Contributes to the Enhanced Anti-Apoptotic Ability of Murine Chronic Myelogenous Leukemia Cells

Background

Leukemic stem cell (LSC) is thought to be responsible for chronic myelogenous leukemia (CML) initiation and relapse. However, the inherent regulation of LSCs remains largely obscure. Herein, we integratedly analyzed miRNA and gene expression alterations in bone marrow (BM) Lin^-Sca1⁺c-Kit⁺ cells (LSKs) of a tet-off inducible CML mouse model, Scl/tTA-BCR/ABL (BA).

Methods

Scl/tTA and TRE-BA transgenic mice were crossed in the presence of doxycycline to get double transgenic mice. Both miRNA and mRNA expression profiles were generated from BM LSKs at 0 and 3 weeks after doxycycline withdrawal. The target genes of differentially expressed miRNAs were predicted, followed by the miRNA-mRNA network construction. In vitro and in vivo experiments were further performed to elucidate their regulation and function in CML progression.

Results

As a result of the integrated analysis and experimental validation, an anti-apoptotic pathway emerged from the fog. miR-142a was identified to be downregulated by enhanced ERK-phosphorylation in BA-harboring cells, thereby relieving its repression on Ciapin1, an apoptosis inhibitor. Moreover, miR-142a overexpression could partially rescue the abnormal anti-apoptotic phenotype and attenuate CML progression.

Conclusion

Taken together, this study explored the miRNA-mRNA regulatory networks in murine CML LSKs and demonstrated that ERK-miR-142a-Ciapin1 axis played an essential role in CML pathogenesis.

Targeting Bcl-2 for cancer therapy

Apoptosis deficiency is one of the most important features observed in neoplastic diseases. The Bcl-2 family is composed of a subset of proteins that act as decisive apoptosis regulators. Research and clinical studies have both demonstrated that the hyperactivation of Bcl-2-related anti-apoptotic effects correlates with cancer occurrence, progression and prognosis, also having a role in facilitating the radio- and chemoresistance of various malignancies. Therefore, targeting Bcl-2 inactivation has provided some compelling therapeutic advantages by enhancing apoptotic sensitivity or reversing drug resistance. Therefore, this pharmacological route turned into one of the most promising routes for cancer treatment. This review discusses some of the well-defined and emerging roles of Bcl-2 as well as its potential clinical value in cancer therapeutics.

miRNAs mediated drug resistance in hematological malignancies

Despite improvements in the therapeutic approaches for hematological malignancies in the last decades, refractory disease still occurs, and cancer drug resistance still remains a major hurdle in the clinical management of these cancer patients. The investigation of this problem has been extensive and different mechanism and molecules have been associated with drug resistance. MicroRNAs (miRNAs) have been described as having an important action in the emergence of cancer, including hematological tumors, and as being major players in their progression, aggressiveness and response to treatments. Moreover, miRNAs have been strongly associated with cancer drug resistance and with the modulation of the sensitivity of cancer cells to a wide array of anticancer drugs. Furthermore, this role has also been reported for miRNAs packaged into extracellular vesicles (EVs-miRNAs), which in turn have been described as essential for the horizontal transfer of drug resistance to sensitive cells. Several studies have been suggesting the use of miRNAs as biomarkers for drug response and clinical outcome prediction, as well as promising therapeutic tools in hematological diseases. Indeed, the combination of miRNA-based therapeutic tools with conventional drugs contributes to overcome drug resistance. This review addresses the role of miRNAs in the pathogenesis of hematological malignances, namely multiple myeloma, leukemias and lymphomas, highlighting their important action (either in their cell-free circulating form or within circulating EVs) in drug resistance and their potential clinical applications.

The Value of Serum MicroRNA Expression Signature in Predicting Refractoriness to Bortezomib-Based Therapy in Multiple Myeloma Patients

Bortezomib is the first-in-class proteasome inhibitor, commonly used in the treatment of multiple myeloma (MM). The mechanisms underlying acquired bortezomib resistance in MM are poorly understood. Several cell-free miRNAs have been found to be aberrantly regulated in MM patients. The aim of this pilot study was to identify a blood-based miRNA signature that predicts bortezomib-based therapy efficacy in MM patients. Thirty MM patients treated with bortezomib-based regimens were studied, including 19 with refractory disease and 11 who were bortezomib sensitive. Serum miRNA expression patterns were identified with miRCURY LNA miRNA miRNome PCR Panels I+II (Exiqon/Qiagen). Univariate analysis found a total of 21 miRNAs to be differentially expressed in patients with MM according to bortezomib sensitivity. Multivariate logistic regression was created and allowed us to discriminate refractory from sensitive patients with a very high AUC of 0.95 (95%CI: 0.84-1.00); sensitivity, specificity and accuracy were estimated as 0.95, 0.91, and 0.93. The model used expression of 3 miRNAs: miR-215-5p, miR-181a-5p and miR-376c-3p. This study is the first to demonstrate that serum expression of several miRNAs differs between patients who are bortezomib refractory and those who are sensitive which may prove useful in studies aimed at overcoming drug resistance in MM treatment.

Downregulated miR‑130a enhances the sensitivity of acute myeloid leukemia cells to Adriamycin

MicroRNA (miR)-130a has been reported to promote cancer growth; however, its role during acute myeloid leukemia (AML) is not completely understood. In the present study, the effects of miR-130a on the sensitivity of AML cells to Adriamycin (Adr) were investigated. 5-Aza-2′-deoxycytidine (5-Aza-dC) was used to stimulate Adr resistance in AML cells, and cell viability and miR-130a expression were determined using the Cell Counting Kit-8 (CCK-8) assay and reverse transcription-quantitative PCR, respectively. miR-130a overexpression and knockdown in Adr-resistant AML cells was performed to investigate the proliferative and invasive abilities of the cells using CCK-8 and Transwell assays, respectively. Furthermore, the effects of miR-130a on the expression of epithelial-mesenchymal transition (EMT)-related proteins in Adr-resistant AML cells were detected using western blot analysis. Pre-treatment with 5-Aza-dC enhanced the cell viability and miR-130a expression of Adr-treated AML cells. Adr and miR-130a expression showed a dose-dependent relationship, with miR-130a expression decreasing with increasing Adr concentrations. Moreover, miR-130a overexpression alleviated the inhibitory effects of Adr on cell viability and invasion, while miR-130a knockdown enhanced the sensitivity of AML cells to Adr. Furthermore, Adr exerted an inhibitory effect on EMT in AML cells, which was rescued by miR-130a overexpression and enhanced by miR-130a knockdown. miR-130a knockdown also increased the sensitivity of AML cells to Adr by decreasing cell viability, invasion and EMT. Therefore, miR-130a knockdown is a potential therapeutic strategy for Adr-resistant AML.

Role of non-coding RNA networks in leukemia progression, metastasis and drug resistance

Early-stage detection of leukemia is a critical determinant for successful treatment of the disease and can increase the survival rate of leukemia patients. The factors limiting the current screening approaches to leukemia include low sensitivity and specificity, high costs, and a low participation rate. An approach based on novel and innovative biomarkers with high accuracy from peripheral blood offers a comfortable and appealing alternative to patients, potentially leading to a higher participation rate.

Recently, non-coding RNAs due to their involvement in vital oncogenic processes such as differentiation, proliferation, migration, angiogenesis and apoptosis have attracted much attention as potential diagnostic and prognostic biomarkers in leukemia. Emerging lines of evidence have shown that the mutational spectrum and dysregulated expression of non-coding RNA genes are closely associated with the development and progression of various cancers, including leukemia. In this review, we highlight the expression and functional roles of different types of non-coding RNAs in leukemia and discuss their potential clinical applications as diagnostic or prognostic biomarkers and therapeutic targets.

MiR-130a-3p Inhibits PRL Expression and Is Associated With Heat Stress-Induced PRL Reduction

MicroRNAs (MiRNAs) play critical roles in the regulation of pituitary function. MiR-130a-3p has previously been found to be down-regulated in prolactinoma, but its roles in prolactin (PRL) regulation and the underlying mechanisms are still unclear. Heat stress has been shown to induce alteration of endocrine hormones and miRNAs expressions. However, there is limited information regarding the emerging roles of miRNAs in heat stress response. In this study, we transfected miR-130a-3p mimic into the pituitary adenoma cells (GH3 cells) to investigate the function of miR-130a-3p in regulating PRL. Our results showed that miR-130a-3p overexpression significantly decreased the PRL expression at both mRNA and protein levels. Subsequently, estrogen receptor α (ERα) was identified as a direct target of miR-130a-3p by bioinformatics prediction, luciferase reporter assay and western blotting assay. Furthermore, the inhibition of ERα caused by estrogen receptor antagonist significantly reduced the PRL expression. Overexpression of ERα rescued the suppressed expression of PRL caused by miR-130a-3p mimic. Besides, we also studied the effect of heat stress on PRL and miRNAs expressions. Interestingly, we found that heat stress reduced PRL and ERα expressions while it increased miR-130a-3p expression both in vitro and in vivo. Taken together, our results indicate that miR-130a-3p represses ERα by targeting its 3'UTR leading to a decrease in PRL expression, and miR-130a-3p is correlative with heat stress-induced PRL reduction, which provides a novel mechanism that miRNAs are involved in PRL regulation.

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.

LncRNA FENDRR attenuates adriamycin resistance via suppressing MDR1 expression through sponging HuR and miR-184 in chronic myelogenous leukaemia cells

Chemotherapy is a major anticancer therapeutic modality, however, multidrug resistance (MDR) is frequently observed and hinders treatment efficacy. Here, we investigated the role and potential mechanism of the long noncoding RNA (lncRNA) FENDRR in adriamycin resistance of chronic myeloid leukaemia (CML) cells. FENDRR overexpression attenuates adriamycin resistance, as shown by increased Rhodamine 123 accumulation, promotion of cell apoptosis in vitro and suppression of tumour growth in vivo. Mechanistically, we identified that FENDRR reduces the interaction of the RNA-binding protein HuR with MDR1 via acting as a sponge, and miR-184 competitively binds to FENDRR with HuR. Thus, the HuR/FENDRR/miR-184 interaction contributes to MDR1 activity. These findings indicate that FENDRR is a potential target for reversing adriamycin resistance.

miR-130a-3p regulated TGF-β1-induced epithelial-mesenchymal transition depends on SMAD4 in EC-1 cells

Metastasis and invasion are the primary causes of malignant progression in esophageal squamous cell carcinoma (ESCC). Epithelial‐mesenchymal transition (EMT) is crucial step of acquisition of "stemness" properties in tumor cells. However, the mechanism of esophageal cancer metastasis remains unclear. This research was designed to explore the role and mechanism of SMAD4 and miR‐130a‐3p in the progression of transforming growth factor‐β (TGF‐β)‐induced EMT in vivo and in vitro. The expression of miR‐130a‐3p in ESCC cell line and normal esophageal epithelial cell was determined by RT‐qPCR. The protein expression levels of TGF‐β‐induced changes in EMT were analyzed by western blotting and immunofluorescence. Dual‐luciferase report assays were used to validate the regulation of miR‐130a‐3p‐SMAD4 axis. The effect of miR‐130a‐3p and SMAD4 in TGF‐β‐induced migration, invasion in the ESCC cell line EC‐1 was investigated by wound healing assays and Transwell assays. Here we found that knocked down SMAD4 could partially reverse TGF‐β‐induced migration, invasion, and EMT progression in the ESCC cell line EC‐1. miR‐130a‐3p, which directly targets SMAD4, is down‐regulated in ESCC. miR‐130a‐3p inhibits the migration and invasion of EC‐1 cells both in vitro and in vivo. Finally, miR‐130a‐3p inhibits TGF‐β‐induced EC‐1 cell migration, invasion, and EMT progression in a SMAD4‐dependent way. In conclusion, this study provides new insights into the mechanism underlying ESCC metastasis. The TGF‐β/miR‐130a‐3p/SMAD4 pathway could be potential targets for clinical treatment of ESCC.

MicroRNA-221 sensitizes chronic myeloid leukemia cells to imatinib by targeting STAT5

MicroRNAs (miRNAs) are involved in various processes from the development to drug resistance of tumors, including chronic myeloid leukemia (CML). In this study, we examined the STAT5-related miRNA-expression profile in CML cell lines (K562 and imatinib-resistant K562/G) by quantitative real-time reverse-transcriptase polymerase chain reactions. MiR-221 expression was markedly decreased in K562/G cells and peripheral blood mononuclear cells from patients with treatment failure, when compared to imatinib-sensitive CML cells and patients with optimal responses respectively. We also observed the expression of STAT5 inversely correlated with miR-221 expression in K562 and KBM5 cells. Additionally, STAT5 was validated as a direct target of miR-221 in dual-luciferase reporter vector assays. MiR-221 restoration and STAT5 knockdown in K562/G cells increased the sensitivity of CML cells to imatinib by reducing the Bcl2: Bax ratio. Collectively, our data suggested that miR-221-STAT5 axis played crucial roles in controlling the sensitivity of CML cells to imatinib.

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.

Complex role of miR-130a-3p and miR-148a-3p balance on drug resistance and tumor biology in esophageal squamous cell carcinoma

miRNAs play a crucial role in cancer development and progression. However, results on the impact of miRNAs on drug sensitivity and tumor biology vary, and most studies to date focussed on either increasing or decreasing miRNA expression levels. Therefore, the current study investigated the role of different expression levels of miR-130a-3p and miR-148a-3p on drug resistance and tumor biology in four esophageal squamous cell carcinoma cell lines. Interestingly, up- and downregulation of both miRNAs significantly increased sensitivity towards chemotherapy. MiRNA modulation also reduced adherence and migration potential, and increased apoptosis rates. Target analyses showed that up- and downregulation of both miRNAs activated the apoptotic p53-pathway via increased expression of either BAX (miR-148a-3p) or Caspase 9 (miR-130a-3p). miR-148a-3p downregulation seemed to mediate its effects primarily via regulation of Bim rather than Bcl-2 levels, whereas we found the opposite scenario following miR-148a-3p upregulation. A similar effect was observed for miR-130a-3p regulating Bcl-2 and XIAP. Our data provide the first evidence that miRNA modulation in both directions may lead to similar effects on chemotherapy response and tumor biology in esophageal squamous cell carcinoma. Most interestingly, up- and downregulation seem to mediate their effects via modulating the balance of several validated or predicted targets.

Abnormal microRNA expression in the course of hematological malignancies

Research on the carcinogenesis process is currently focused primarily on understanding its genetic basis and molecular abnormalities that may be predictive factors and therapeutic targets. It was clearly confirmed recently that microRNAs are involved in the mechanisms of leukocyte development, differentiation, and apoptosis, as well as in the pathogenesis of proliferative diseases of the hematopoietic system. Currently, research strategies allow determination of the deregulation of microRNA profiles in relation to other cytogenetic aberrations, as well as prognostic factors and primary end points. The problem of the possibility of their use as therapeutic targets is also increasingly discussed. In this article, we analyze literature data on abnormalities in microRNA expression in proliferative diseases of the hematopoietic system in the context of classic cytogenetic and molecular aberrations.

MicroRNA-130a-3p suppresses cell migration and invasion by inhibition of TBL1XR1-mediated EMT in human gastric carcinoma

MiR-130a-3p was found to play tumor suppressor role in most human cancers, except for gastric cancer. However, in this study, we demonstrated that miR-130a-3p was significantly down-regulated in gastric carcinoma (GC) tissues compared with adjacent non-neoplastic tissues, and decreased miR-130a-3p expression was associated with shorter overall survival (OS) and was an independent prognostic factor for OS in GC patients. Over-expression of miR-130a-3p remarkably inhibited not only GC cell migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro, but also tumorigenesis and lung metastasis in the chick embryo chorioallantoic membrane (CAM) assay in vivo. Conversely, inhibition of miR-130a-3p resulted in opposite phenotype changes in GC cells. Furthermore, TBL1XR1 was identified as a direct target of miR-130a-3p, and reintroduction of TBL1XR1 into miR-130a-3p-transfected MGC-803 cells reversed the inhibitory effects of miR-130a-3p on GC cell migration, invasion and EMT. Taken together, our data suggested that miR-130a-3p suppressed aggressive phenotype of GC cells partially by direct targeting and decreasing TBL1XR1 and subsequent EMT process.

miR-130a Deregulates PTEN and Stimulates Tumor Growth

H-RasV12 oncogene has been shown to promote autophagic cell death. Here, we provide evidence of a contextual role for H-RasV12 in cell death that is varied by its effects on miR-130a. In E1A-immortalized murine embryo fibroblasts, acute expression of H-RasV12 promoted apoptosis, but not autophagic cell death. miRNA screens in this system showed that miR-130a was strongly downregulated by H-RasV12 in this model system. Enforced expression of miR-130a increased cell proliferation in part via repression of PTEN. Consistent with this effect, miR-130a overexpression in human breast cancer cells promoted Akt phosphorylation, cell survival, and tumor growth. In clinical specimens of multiple human cancers, expression of miR-130 family members correlated inversely with PTEN expression. Overall, our results defined miR-130a as an oncogenic miRNA that targets PTEN to drive malignant cell survival and tumor growth. Cancer Res; 77(22); 6168-78. ©2017 AACR.

Downregulation of miR-130a promotes cell growth and epithelial to mesenchymal transition by activating HMGB2 in glioma

Aberrant expression of miR-130a is usually found in cancer studies; however, the role of miR-130a has seldom been reported in glioma. We explored miR-130a's function and the underlying mechanism in glioma. It was found that miR-130a expression was significantly down-regulated in glioma tissues and cell lines. Overexpression of miR-130a decreased glioma cell growth and invasion both in vitro and in vivo. We identified the oncogene HMGB2 as a downstream target of miR-130a by using luciferase and western blot assays. Knockdown of HMGB2 mimicked the effect of miR-130a in glioma cells. Taken together, our study demonstrate that miR-130a may function as a tumor suppressor in glioma and suggest that miR-130a is a potential therapeutic target for glioma patients.

MicroRNA-130a is upregulated in colorectal cancer and promotes cell growth and motility by directly targeting forkhead box F2

Colorectal cancer (CRC) is one of the most prevalent cancers among males and females worldwide. Despite progress in diagnostic and therapeutic strategies for CRC patients, the prognosis for patients with advanced CRC remains poor. MicroRNAs (miRNAs/miRs) are a class of highly conserved short, endogenously expressed and single‑stranded non‑coding RNAs. In recent years, increasing studies have demonstrated that dysregulation of miRNAs is closely associated with CRC carcinogenesis and progression. The aim of the present study was to explore the expression, roles and underlying molecular mechanism of miR‑130a in CRC. The results indicated that miR‑130a was significantly upregulated in CRC, and that miR‑130a expression levels were correlated with TNM stage and lymph node metastasis of CRC. Inhibition of miR‑130a markedly suppressed colorectal cancer cell proliferation, migration and invasion. Furthermore, forkhead box F2 (FOXF2) was identified as a direct downstream target gene of miR‑130a in colorectal cancer. Downregulation of FOXF2 could partially reverse the functions induced by miR‑130a under‑expression in CRC cells. These findings suggested that miR‑130a can regulate FOXF2 and function as an oncogene in CRC. Therefore, miR‑130a may serve as a useful therapeutic agent for miRNA‑based CRC targeted therapy.

Anti-leukemic activity of microRNA-26a in a chronic lymphocytic leukemia mouse model

Dysregulation of microRNAs (miRNAs) plays an important role in the pathogenesis of chronic lymphocytic leukemia (CLL). The Eμ-TCL1 transgenic mouse develops a form of leukemia that is similar to the aggressive type of human B-CLL, and this valuable model has been widely used for testing novel therapeutic approaches. Here, we adopted this model to investigate the potential effects of miR-26a, miR-130an and antimiR-155 in CLL therapy. Improved delivery of miRNA molecules into CLL cells was obtained by developing a novel system based on lipid nanoparticles conjugated with an anti-CD38 monoclonal antibody. This methodology has proven to be highly effective in delivering miRNA molecules into leukemic cells. Short- and long-term experiments showed that miR-26a, miR-130a and anti-miR-155 increased apoptosis after in vitro and in vivo treatment. Of this miRNA panel, miR-26a was the most effective in reducing leukemic cell expansion. Following long-term treatment, apoptosis was readily detectable by analyzing cleavage of PARP and caspase-7. These effects could be directly attributed to miR-26a, as confirmed by significant downregulation of its proven targets, namely cyclin-dependent kinase 6 and Mcl1. The results of this study are relevant to two distinct areas. The first is related to the design of a technical strategy and to the selection of CD38 as a molecular target on CLL cells, both consenting efficient and specific intracellular transfer of miRNA. The original scientific finding inferred from the above approach is that miR-26a can elicit in vivo anti-leukemic activities mediated by increased apoptosis.

Mechanism of Mongolian medical warm acupuncture in treating insomnia by regulating miR-101a in rats with insomnia

MicroRNAs (miRNAs or miRs) and the target genes before and after warm acupuncture at the genetic level were assessed, and the cytokines and neurotransmitters related to insomnia were studied. Male Sprague-Dawley rats were used to create PCPA insomnia rat models and randomly divided into the normal, model, warm acupuncture, and drug groups. The Dinghui Acupoint, Heyi Acupoint, and Xin Acupoint were inserted in the Mongolian medicine warm acupuncture group. The differential expression profile of microRNA in the brain tissue of the insomnia rats was determined before and after Mongolian medicine warm acupuncture for establishment of miR-101a mimics and inhibitor. qPCR was used to detect the expression level of miR-101a. Western blotting was used to detect the expression level of PAX8. The rats receiving Mongolian medicine warm acupuncture had 141 miRNAs with differential expression compared with the normal rats. The expression level of miR-101a in the cells of the hippocampus of the insomnia rats transfected with miR-101a mimics increased significantly at 72 h (P<0.05). The activity of the neuronal cells transfected with miR-101a inhibitor increased significantly at 72 h (P<0.05). The western blotting result indicated that the expression of the PAX8 protein in the neuronal cells of the insomnia model rats was inhibited and downregulated significantly at 72 h after addition of miR-101a mimics compared with that in the scramble added group (P<0.01). The levels of the interleukins IL-1, IL-2, and IL-6 and the tumor necrosis factor-α in the hypothalamus, hippocampus, and prefrontal cortex decreased significantly compared with those in the blank control group (P<0.05). The levels of noradrenaline, dopamine, and glutamic decreased significantly following warm acupuncture or western medicine treatment (P<0.05). In conclusion, this study demonstrates that the upregulation of miR-101a in the rats treated with warm acupuncture is directly associated with PAX8 regulation.

Clinical significance of microRNAs in chronic and acute human leukemia

Small non-coding microRNAs (miRNAs) are epigenetic regulators that target specific cellular mRNA to modulate gene expression patterns and cellular signaling pathways. miRNAs are involved in a wide range of biological processes and are frequently deregulated in human cancers. Numerous miRNAs promote tumorigenesis and cancer progression by enhancing tumor growth, angiogenesis, invasion and immune evasion, while others have tumor suppressive effects (Hayes, et al., Trends Mol Med 20(8): 460-9, 2014; Stahlhut and Slack, Genome Med 5 (12): 111, 2013). The expression profile of cancer miRNAs can be used to predict patient prognosis and clinical response to treatment (Bouchie, Nat Biotechnol 31(7): 577, 2013). The majority of miRNAs are intracellular localized, however circulating miRNAs have been detected in various body fluids and represent new biomarkers of solid and hematologic cancers (Fabris and Calin, Mol Oncol 10(3):503-8, 2016; Allegra, et al., Int J Oncol 41(6): 1897-912, 2012). This review describes the clinical relevance of miRNAs, lncRNAs and snoRNAs in the diagnosis, prognosis and treatment response in patients with chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML), acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML) and acute adult T-cell leukemia (ATL).

Transcription Factor HBP1 Enhances Radiosensitivity by Inducing Apoptosis in Prostate Cancer Cell Lines

Radiotherapy for prostate cancer has been gradually carried out in recent years; however, acquired radioresistance often occurred in some patients after radiotherapy. HBP1 (HMG-box transcription factor 1) is a transcriptional inhibitor which could inhibit the expression of dozens of oncogenes. In our previous study, we showed that the expression level of HBP1 was closely related to prostate cancer metastasis and prognosis, but the relationship between HBP1 and radioresistance for prostate cancer is largely unknown. In this study, the clinical data of patients with prostate cancer was compared, and the positive correlation was revealed between prostate cancer brachytherapy efficacy and the expression level of HBP1 gene. Through research on prostate cancer cells in vitro, we found that HBP1 expression levels were negatively correlated with oncogene expression levels. Furthermore, HBP1 overexpression could sensitize prostate cancer cells to radiation and increase apoptosis in prostate cancer cells. In addition, animal model was employed to analyze the relationship between HBP1 gene and prostate cancer radiosensitivity in vivo; the result showed that knockdown of HBP1 gene could decrease the sensitivity to radiation of xenograft. These studies identified a specific molecular mechanism underlying prostate cancer radiosensitivity, which suggested HBP1 as a novel target in prostate cancer radiotherapy.

MiR-130b inhibits proliferation and induces apoptosis of gastric cancer cells via CYLD

A role of microRNA-130b (miR-130b) in the carcinogenesis of gastric cancer remains undetermined. In this study, we studied the effects and mechanism of miR-130b to the gastric cell proliferation and apoptosis. We found that the levels of miR-130b significantly up-regulated in gastric cancer tissue, compared to the paired adjacent non-tumor gastric tissue. The miR-130b levels in gastric cancer cell lines were significantly higher than those in control normal gastric tissues. Transfection with the miR-130b mimic enhanced the cell proliferation and suppressed cell apoptosis in gastric cancer cells, while transfection with the anti-sense of miR-130b (anti-miR-130b) suppressed cell proliferation and induced cell apoptosis in gastric cancer cells. Bioinformatics analyses showed that cylindromatosis gene (CYLD) was a potential target gene of miR-130b. The luciferase activity assay and western blot verified that miR-130b targeted CYLD messenger RNA (mRNA) to modulate its protein levels. Together, our study suggests that aberrantly expressed miR-130b may regulate cell apoptosis and proliferation of human gastric cancer cells via CYLD, which appears to be a promising therapeutic target for gastric cancer.