MicroRNA-195 acts as a tumor suppressor by directly targeting Wnt3a in HepG2 hepatocellular carcinoma cells

miR-195b is required for proper cellular homeostasis in the elderly

Over the last decade we have witnessed an increasing number of studies revealing the functional role of non-coding RNAs in a multitude of biological processes, including cellular homeostasis, proliferation and differentiation. Impaired expression of non-coding RNAs can cause distinct pathological conditions, including herein those affecting the gastrointestinal and cardiorespiratory systems, respectively. miR-15/miR-16/miR-195 family members have been broadly implicated in multiple biological processes, including regulation of cell proliferation, apoptosis and metabolism within distinct tissues, such as heart, liver and lungs. While the functional contribution of miR-195a has been reported in multiple biological contexts, the role of miR-195b remains unexplored. In this study we dissected the functional role of miR-195b by generating CRISPR-Cas9 gene edited miR-195b deficient mice. Our results demonstrate that miR-195b is dispensable for embryonic development. miR-195b-/- mice are fertile and displayed no gross anatomical and/or morphological defects. Mechanistically, cell cycle regulation, metabolism and oxidative stress markers are distinctly impaired in the heart, liver and lungs of aged mice, a condition that is not overtly observed at midlife. The lack of overt functional disarray during embryonic development and early adulthood might be due to temporal and tissue-specific compensatory mechanisms driven by selective upregulation miR-15/miR-16/miR-195 family members. Overall, our data demonstrated that miR-195b is dispensable for embryonic development and adulthood but is required for cellular homeostasis in the elderly.

An epigenetic modulator with promising therapeutic impacts against gastrointestinal cancers: A mechanistic review on microRNA-195

Due to their high prevalence, gastrointestinal cancers are one of the key causes of cancer-related death globally. The development of drug-resistant cancer cell populations is a major factor in the high mortality rate, and it affects about half of all cancer patients. Because of advances in our understanding of cancer molecular biology, non-coding RNAs (ncRNAs) have emerged as critical factors in the initiation and development of gastrointestinal cancers. Gene expression can be controlled in several ways by ncRNAs, including through epigenetic changes, interactions between microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) and proteins, and the function of lncRNAs as miRNA precursors or pseudogenes. As lncRNAs may be detected in the blood, circulating ncRNAs have emerged as a promising new class of non-invasive cancer biomarkers for use in the detection, staging, and prognosis of gastrointestinal cancers, as well as in the prediction of therapy efficacy. In this review, we assessed the role lncRNAs play in the progression, and maintenance of colorectal cancer, and how they might be used as therapeutic targets in the future.

Carbon Monoxide-Releasing Molecule-3 Enhances Osteogenic Differentiation of Rat Bone Marrow Mesenchymal Stem Cells via miR-195-5p/Wnt3a Pathway

Purpose

Bone marrow-derived mesenchymal stem cells (BMSCs) are hopeful in promoting bone regeneration as their pluripotency in differentiation. Our previous study showed that carbon monoxide-releasing molecule-3 (CORM-3) increased the osteogenic differentiation of rat BMSCs in vitro. However, the mechanism remained unclear. MicroRNAs (miRNAs) play a very important role in modulating the osteogenic differentiation of BMSCs. Therefore, we researched the miRNAs involved in CORM-3-stimulated osteogenic differentiation.

Methods

The CORM-3-stimulated osteogenic differentiation of rat BMSCs was further studied in vivo. Based on the gene sequencing experiment, the rat BMSCs were transfected with miR-195-5p mimics and inhibitor, pcDNA3.1-Wnt3a and Wnt3a siRNA. The osteogenic differentiation of rat BMSCs was measured by quantitative real-time polymerase chain reaction, Western blot and alizarin red staining. Additionally, the targeting relationship between miR-195-5p and Wnt3a was confirmed by the dual-luciferase assay.

Results

MiR-195-5p was down-expressed during the CORM-3-stimulated osteogenic differentiation of rat BMSCs. CORM-3-stimulated osteogenic differentiation of rat BMSCs was inhibited with miR-195-5p overexpression, evidenced by significantly reduced mRNA and protein expressions of runt-related transcription factor 2 and osteopontin, and matrix mineralization demonstrated. On the contrary, the osteogenic differentiation was enhanced with inhibition of miR-195-5p. CORM-3-stimulated osteogenic differentiation of rat BMSCs was increased by overexpression of Wnt3a, while the opposite was observed in the Wnt3a-deficient cells. Moreover, the decreased osteogenic differentiation capacity by increased expression of miR-195-5p was rescued by Wnt3a overexpression, showing miR-195-5p directly targeted Wnt3a.

Conclusion

These results demonstrate that CORM-3 promoted osteogenic differentiation of rat BMSCs via miR-195-5p/Wnt3a, which bodes well for the application of CORM-3 in the treatment of periodontal disease and other bone-defect diseases.

miRNAs inspirations in hepatocellular carcinoma: Detrimental and favorable aspects of key performers

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related deaths worldwide. HCC initiation, progression, and therapy failure are all influenced by various variables, including microRNAs (miRNAs). miRNAs are short non-coding RNA sequences that modulate target mRNA expression by deteriorating or repressing translation. miRNAs play an imperative role in HCC pathogenesis by triggering the induction of cancer stem cells (CSCs) and their proliferation, while also delaying apoptosis, sustaining the cell cycle, and inspiring angiogenesis, invasion, and metastasis. Additionally, miRNAs modulate crucial HCC-related molecular pathways such as the p53 pathway, the Wnt/β-catenin pathway, VEGFR2, and PTEN/PI3K/AKT pathway. Consequently, the goal of this review was to give an up-to-date overview of oncogenic and tumor suppressor (TS) miRNAs, as well as their potential significance in HCC pathogenesis and treatment responses, highlighting their underpinning molecular pathways in HCC initiation and progression. Similarly, the biological importance and clinical application of miRNAs in HCC are summarized.

Wnt/β-catenin signaling in cancers and targeted therapies

Wnt/β-catenin signaling has been broadly implicated in human cancers and experimental cancer models of animals. Aberrant activation of Wnt/β-catenin signaling is tightly linked with the increment of prevalence, advancement of malignant progression, development of poor prognostics, and even ascendence of the cancer-associated mortality. Early experimental investigations have proposed the theoretical potential that efficient repression of this signaling might provide promising therapeutic choices in managing various types of cancers. Up to date, many therapies targeting Wnt/β-catenin signaling in cancers have been developed, which is assumed to endow clinicians with new opportunities of developing more satisfactory and precise remedies for cancer patients with aberrant Wnt/β-catenin signaling. However, current facts indicate that the clinical translations of Wnt/β-catenin signaling-dependent targeted therapies have faced un-neglectable crises and challenges. Therefore, in this study, we systematically reviewed the most updated knowledge of Wnt/β-catenin signaling in cancers and relatively targeted therapies to generate a clearer and more accurate awareness of both the developmental stage and underlying limitations of Wnt/β-catenin-targeted therapies in cancers. Insights of this study will help readers better understand the roles of Wnt/β-catenin signaling in cancers and provide insights to acknowledge the current opportunities and challenges of targeting this signaling in cancers.

MicroRNA-195 controls MICU1 expression and tumor growth in ovarian cancer

MICU1 is a mitochondrial inner membrane protein that inhibits mitochondrial calcium entry; elevated MICU1 expression is characteristic of many cancers, including ovarian cancer. MICU1 induces both glycolysis and chemoresistance and is associated with poor clinical outcomes. However, there are currently no available interventions to normalize aberrant MICU1 expression. Here, we demonstrate that microRNA-195-5p (miR-195) directly targets the 3' UTR of the MICU1 mRNA and represses MICU1 expression. Additionally, miR-195 is under-expressed in ovarian cancer cell lines, and restoring miR-195 expression reestablishes native MICU1 levels and the associated phenotypes. Stable expression of miR-195 in a human xenograft model of ovarian cancer significantly reduces tumor growth, increases tumor doubling times, and enhances overall survival. In conclusion, miR-195 controls MICU1 levels in ovarian cancer and could be exploited to normalize aberrant MICU1 expression, thus reversing both glycolysis and chemoresistance and consequently improving patient outcomes.

MicroRNA dysregulation interplay with childhood abdominal tumors

Abdominal tumors (AT) in children account for approximately 17% of all pediatric solid tumor cases, and frequently exhibit embryonal histological features that differentiate them from adult cancers. Current molecular approaches have greatly improved the understanding of the distinctive pathology of each tumor type and enabled the characterization of novel tumor biomarkers. As seen in abdominal adult tumors, microRNAs (miRNAs) have been increasingly implicated in either the initiation or progression of childhood cancer. Moreover, besides predicting patient prognosis, they represent valuable diagnostic tools that may also assist the surveillance of tumor behavior and treatment response, as well as the identification of the primary metastatic sites. Thus, the present study was undertaken to compile up-to-date information regarding the role of dysregulated miRNAs in the most common histological variants of AT, including neuroblastoma, nephroblastoma, hepatoblastoma, hepatocarcinoma, and adrenal tumors. Additionally, the clinical implications of dysregulated miRNAs as potential diagnostic tools or indicators of prognosis were evaluated.

Long intergenic noncoding RNA SNHG16 interacts with miR-195 to promote proliferation, invasion and tumorigenesis in hepatocellular carcinoma

Long non-coding RNAs (lncRNAs) have been confirmed crucial regulators in tumorgenesis. Small nucleolar RNA host gene 16 (SNHG16) has been recently shown to be dysregulated, which uncovered to be a potential oncogene in some cancers. However, the biological function and potential mechanism of SNHG16 in hepatocellular carcinoma (HCC) remain unclear. In our study, our observations showed that the expression level of SNHG16 in HCC tissues and cell lines was upregulated compared with adjacent noncancerous tissues and normal cells. In vitro, loss-of-function experiments revealed that SNHG16 knockdown suppressed the proliferation and weakened invasion of SMMC7721 and HepG2 cells. miR-195 expression was significantly decreased in HCC tissues and negatively correlated with SNHG16 expression. Furthermore, RIP and dual luciferase reporter assays showed that SNHG16 acted as an endogenous sponge by directly binding to miR-195 and downregulated its expression. SNHG16 overexpression inverted the inhibitory effect of miR-195 on proliferation and invasion of SMMC7721 and HepG2 cells. Additionally, SNHG16 depletion resulted in lower tumor growth and weight loss, in vivo. In conclusion, our findings reported that the oncogenic role of SNHG16 in HCC tumorigenesis through a novel SNHG16-miR-195 axis, which provided a novel insight for HCC and helped to probe a potential therapeutic target for the deadly disease.

Role of Wnt3a in the pathogenesis of cancer, current status and prospective

The Wnt signaling pathway plays a critical role in initiation, progression, invasion and metastasis of cancer. Wnt3a as a canonical Wnt ligand is strongly implicated in the etiology and pathology of a number of diseases including cancer. Depending on cancer type, Wnt3a enhances or suppresses metastasis, cell proliferation and apoptosis of cancer cells. This review summarizes the role of Wnt3a in the pathogenesis of different cancers including colorectal, prostate, hepatocellular, lung and leukemia, for promoting greater understanding and clinical management of these diseases.

Screening of prognostic biomarkers for endometrial carcinoma based on a ceRNA network

Objective

This study aims to reveal the regulation network of lncRNAs-miRNAs-mRNA in endometrial carcinoma (EC), to investigate the underlying mechanisms of EC occurrence and progression, to screen prognostic biomarkers.

Methods

RNA-seq and miRNA-seq data of endometrial carcinoma were downloaded from the TCGA database. Edge.R package was used to screen differentially expressed genes. A database was searched to determine differentially expressed lncRNA-miRNA and miRNA-mRNA pairs, to construct the topological network of ceRNA, and to elucidate the key RNAs that are for a prognosis of survival.

Results

We screened out 2632 mRNAs, 1178 lncRNAs and 189 miRNAs that were differentially expressed. The constructed ceRNA network included 97 lncRNAs, 20 miRNAs and 73 mRNAs. Analyzing network genes for associations with prognosies revealed 169 prognosis-associated RNAs, including 92 lncRNAs, 16miRNAs and 61 mRNAs.

Conclusion

Our results reveal new potential mechanisms underlying the carcinogenesis and progression of endometrial carcinoma.

microRNAs: Key players in virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is known as one of the major health problems worldwide. Pathological analysis indicated that a variety of risk factors including genetical (i.e., alteration of tumor suppressors and oncogenes) and environmental factors (i.e., viruses) are involved in beginning and development of HCC. The understanding of these risk factors could guide scientists and clinicians to design effective therapeutic options in HCC treatment. Various viruses such as hepatitis B virus (HBV) and hepatitis C virus (HCV) via targeting several cellular and molecular pathways involved in HCC pathogenesis. Among various cellular and molecular targets, microRNAs (miRNAs) have appeared as key players in HCC progression. miRNAs are short noncoding RNAs which could play important roles as oncogenes or tumor suppressors in several malignancies such as HCC. Deregulation of many miRNAs (i.e., miR-222, miR-25, miR-92a, miR-1, let-7f, and miR-21) could be associated with different stages of HCC. Besides miRNAs, exosomes are other particles which are involved in HCC pathogenesis via targeting different cargos, such as DNAs, RNAs, miRNAs, and proteins. In this review, we summarize the current knowledge of the role of miRNAs and exosomes as important players in HCC pathogenesis. Moreover, we highlighted HCV- and HBV-related miRNAs which led to HCC progression.

MicroRNA-195: a review of its role in cancers

MicroRNAs (miRNAs) are small and highly conserved noncoding RNAs that regulate gene expression at the posttranscriptional level by binding to the 3′-UTR of target mRNAs. Recently, increasing evidence has highlighted their profound roles in various pathological processes, including human cancers. Deregulated miRNAs function as either oncogenes or tumor suppressor genes in multiple cancer types. Among them, miR-195 has been reported to significantly impact oncogenicity in various neoplasms by binding to critical genes and signaling pathways, enhancing or inhibiting the progression of cancers. In this review, we focus on the expression of miR-195 in regulatory mechanisms and tumor biological processes and discuss the future potential therapeutic implications of diverse types of human malignancies.

The intragenic mRNA-microRNA regulatory network during telogen-anagen hair follicle transition in the cashmere goat

It is widely accepted that the periodic cycle of hair follicles is controlled by the biological clock, but the molecular regulatory mechanisms of the hair follicle cycle have not been thoroughly studied. The secondary hair follicle of the cashmere goat is characterized by seasonal periodic changes throughout life. In the hair follicle cycle, the initiation of hair follicles is of great significance for hair follicle regeneration. To provide a reference for hair follicle research, our study compared differences in mRNA expression and microRNA expression during the growth and repose stages of cashmere goat skin samples. Through microRNA and mRNA association analysis, we found microRNAs and target genes that play major regulatory roles in hair follicle initiation. We further constructed an mRNA-microRNA interaction network and found that hair follicle initiation and development were related to MiR-195 and the genes CHP1, SMAD2, FZD6 and SIAH1.

The Role of MicroRNAs in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers, leading to the second cancer-related death in the global. Although the treatment of HCC has greatly improved over the past few decades, the survival rate of patients is still quite low. Thus, it is urgent to explore new therapies, especially seek for more accurate biomarkers for early diagnosis, treatment and prognosis in HCC. MicroRNAs (miRNAs), small noncoding RNAs, are pivotal participants and regulators in the development and progression of HCC. Great progress has been made in the studies of miRNAs in HCC. The key regulatory mechanisms of miRNAs include proliferation, apoptosis, invasion, metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, drug resistance and autophagy in HCC. And exosomal miRNAs also play important roles in proliferation, invasion, metastasis, and drug resistance in HCC by regulating gene expression in the target cells. In addition, some miRNAs, including exosomal miRNAs, can be as potential diagnostic and prediction markers in HCC. This review summarizes the latest researches development of miRNAs in HCC in recent years.

MiR-195 suppresses colon cancer proliferation and metastasis by targeting WNT3A

MicroRNAs (miRNAs) are a novel class of diagnostic and therapeutic target in cancer. Here, we aimed to explore the effects and mechanism of miR-195 regulation in colon cancer. The expressions of several putative miRNAs in colon tumors, compared to those in normal tissues, were investigated by bioinformatical analysis of a Gene Expression Omnibus database. Quantitative real-time PCR analysis (qRT-PCR) was used to validate the identified changes in normal tissues, primary tumors, and metastatic tumors. MTT, soft agar colony formation, and transwell assays were used to evaluate the effects of miR-195 overexpression or inhibition on cell viability, proliferation, migration, and invasion. Targets of miR-195 were identified by TargetScan, and subsequently verified by qRT-PCR and Western blot. The role of miR-195 in the β-catenin pathway was also studied using RT-PCR and Western blot. MiR-195 expression was downregulated in colon carcinoma tissues and negatively correlated with the metastatic potential. While transfecting miR-195 mimics decreased the proliferation, migration, and invasion of colon cancer cells, miR-195 inhibition exerted opposing effects. WNT3A was identified as a direct target of miR-195. β-catenin was also downregulated by miR-195 in colon cancers. MiR-195 downregulation is associated with the enhanced proliferation, migration, and invasion of colon cancer. MiR-195 directly downregulates WNT3A. Our results indicate that miR-195 is a potential diagnostic marker and therapeutic target for improving the clinical management of colon cancer.

MiR-195 Suppresses Cervical Cancer Migration and Invasion Through Targeting Smad3

OBJECTIVE

MicroRNAs (miRNAs) play crucial roles in cervical cancer development and progression. The purposes of this study were to investigate the role of miR-195 in cervical cancer and clarify the regulation of Smad3 by miR-195.

METHODS

Quantitative real-time polymerase chain reaction was used to examine miR-195 expression in cervical cancer tissues and cell lines. The clinicopathological significance of miR-195 down-regulation was further analyzed. Transwell migration and invasion assays were performed. A luciferase reporter assay was conducted to confirm the target gene of miR-195, and the results were validated in cervical cancer tissues and cell lines.

RESULTS

MiR-195 was significantly decreased in clinical tissues and cervical cancer cell lines. The low miR-195 level was significantly correlated with higher International Federation of Gynecology and Obstetrics stage, node metastasis, and deep stromal invasion. Up-regulation of miR-195 suppressed cell migration and invasion in vitro. Smad3 was verified as a direct target of miR-195, which was further confirmed by the inverse expression of miR-195 and Smad3 in patients' specimens.

CONCLUSIONS

The newly identified miR-195/Smad3 pathway provides an insight into cervical cancer metastasis and may represent a novel therapeutic target.

MicroRNA‑195 inhibits cell proliferation, migration and invasion in laryngeal squamous cell carcinoma by targeting ROCK1

Laryngeal carcinoma is the second most common malignancy of the head and neck cancers. The most common type of laryngeal carcinoma comprises laryngeal squamous cell carcinoma (LSCC), which accounts for ~95% of laryngeal carcinoma cases. Despite great progress in diagnostic and therapeutic techniques over the last few decades, the prognosis for patients with LSCC remains poor. A number of studies reported that various miRNAs are dysregulated in LSCC and serve critical roles in LSCC tumorigenesis and tumor development. The present study aimed to evaluate the expression level of microRNA (miR)‑195 and its possible roles in LSCC. Briefly, miR‑195 was downregulated in LSCC tissues and cell lines. In addition, low miR‑195 expression was significantly correlated with lymph node metastasis and TNM stage of LSCC patients. Further study has demonstrated that miR‑195 overexpression suppressed cell proliferation, migration and invasion of LSCC. Moreover, rho‑associated kinase 1 (ROCK1) was identified as a direct target gene of miR‑195. Downregulation of ROCK1 exerted similar roles to that of miR‑195 overexpression in LSCC, suggesting ROCK1 was a direct downstream target of miR‑195. These findings elucidated a novel molecular mechanism for the pathogenic mechanism in LSCC carcinogenesis and progression, and may have a potential role in the treatment of patients with LSCC.

MicroRNA-195 inhibits the proliferation and invasion of pancreatic cancer cells by targeting the fatty acid synthase/Wnt signaling pathway

Emerging evidence suggests that microRNAs are critical regulators of cancer development and progression. MicroRNA-195 has been reported as a cancer-related microRNA in many human cancers. However, the role of microRNA-195 in pancreatic cancer remains largely unknown. Here, we show that microRNA-195 is downregulated in pancreatic cancer tissues and cell line. Also, we show that overexpression of microRNA-195 inhibits the proliferation and invasion of pancreatic cancer cells, whereas suppression of microRNA-195 promotes proliferation and invasion. We show that microRNA-195 directly targets the fatty acid synthase enzyme and negatively regulates the expression of fatty acid synthase. Also, we show that fatty acid synthase expression is inversely correlated with microRNA-195 expression in pancreatic cancer tissues. Moreover, our results show that microRNA-195 inhibits Wnt signaling in pancreatic cancer cells. By restoring fatty acid synthase expression, we were able to reverse the antitumor effects of microRNA-195 in pancreatic cancer cells. Taken together, our findings show that microRNA-195 inhibits pancreatic cancer cell proliferation and invasion by regulating the fatty acid synthase/Wnt signaling pathway, suggesting a tumor suppressive role for microRNA-195 in the development and progression of pancreatic cancer. Thus, inhibiting fatty acid synthase by microRNA-195 may serve as a novel therapeutic approach for the treatment of pancreatic cancer.

MicroRNA-195 inhibits the behavior of cervical cancer tumors by directly targeting HDGF

MicroRNAs (miRNAs/miRs) are a class of conserved non-coding endogenous small regulatory RNAs that regulate target gene expression by binding to the 3′-untranslated region of target mRNAs in a base-pairing manner, resulting in repression of transcription or degradation of target mRNAs. It has been demonstrated previously that the abnormal expression of miRNAs is involved in the carcinogenesis and progression of cervical cancer. The aim of the present study was to investigate the expression, biological functions and underlying molecular mechanisms of miR-195 in cervical cancer. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression level of miR-195 in cervical cancer tissues and cell lines. Following transfection, an MTT assay, cell migration and invasion assays, western blot analysis and a dual-luciferase reporter assay were performed in human cervical cancer cells. In the present study, it was identified that miR-195 was downregulated in cervical cancer tissues and cell lines. Additionally, upregulation of miR-195 and knockdown of hepatoma-derived growth factor (HDGF) inhibited proliferation, migration and invasion of cervical cancer cells. Furthermore, a dual-luciferase reporter assay identified that HDGF was a direct target gene of miR-195. RT-qPCR and western blot analysis demonstrated that miR-195 mimic inhibited HDGF expression at the mRNA and protein levels, whereas miR-195 inhibitor enhanced HDGF expression at the mRNA and protein levels. These results indicated that miR-195 targeted HDGF to inhibit the behavior of tumors in cervical cancer. These results also suggested that miR-195 was a potential therapeutic biomarker of cervical cancer.

Platelet microparticles infiltrating solid tumors transfer miRNAs that suppress tumor growth

Platelet-derived microparticles (PMPs) are associated with enhancement of metastasis and poor cancer outcomes. Circulating PMPs transfer platelet microRNAs (miRNAs) to vascular cells. Solid tumor vasculature is highly permeable, allowing the possibility of PMP-tumor cell interaction. Here, we show that PMPs infiltrate solid tumors in humans and mice and transfer platelet-derived RNA, including miRNAs, to tumor cells in vivo and in vitro, resulting in tumor cell apoptosis. MiR-24 was a major species in this transfer. PMP transfusion inhibited growth of both lung and colon carcinoma ectopic tumors, whereas blockade of miR-24 in tumor cells accelerated tumor growth in vivo, and prevented tumor growth inhibition by PMPs. Conversely, Par4-deleted mice, which had reduced circulating microparticles (MPs), supported accelerated tumor growth which was halted by PMP transfusion. PMP targeting was associated with tumor cell apoptosis in vivo. We identified direct RNA targets of platelet-derived miR-24 in tumor cells, which included mitochondrial mt-Nd2, and Snora75, a noncoding small nucleolar RNA. These RNAs were suppressed in PMP-treated tumor cells, resulting in mitochondrial dysfunction and growth inhibition, in an miR-24-dependent manner. Thus, platelet-derived miRNAs transfer in vivo to tumor cells in solid tumors via infiltrating MPs, regulate tumor cell gene expression, and modulate tumor progression. These findings provide novel insight into mechanisms of horizontal RNA transfer and add multiple layers to the regulatory roles of miRNAs and PMPs in tumor progression. Plasma MP-mediated transfer of regulatory RNAs and modulation of gene expression may be a common feature with important outcomes in contexts of enhanced vascular permeability.

Roles of MicroRNA-195 in cardiomyocyte apoptosis induced by myocardial ischemia-reperfusion injury

This study aims to investigate microRNA-195 (miR-195) expression in myocardial ischaemia-reperfusion (I/R) injury and the roles of miR-195 in cardiomyocyte apoptosis though targeting Bcl-2. A mouse model of I/R injury was established. MiR- 195 expression levels were detected by real-time quantitative PCR (qPCR), and the cardiomyocyte apoptosis was detected by TUNEL assay. After cardiomyocytes isolated from neonatal rats and transfected with miR-195 mimic or inhibitor, the hypoxia/reoxygenation (H/R) injury model was established. Cardiomyocyte apoptosis and mitochondrial membrane potential were evaluated using flow cytometry. Bcl-2 and Bax mRNA expressions were detected by RT-PCR. Bcl-2, Bax and cytochrome c (Cyt-c) protein levels were determined by Western blot. Caspase-3 and caspase-9 activities were assessed by luciferase assay. Compared with the sham group, miR-195 expression levels and rate of cardiomyocyte apoptosis increased significantly in I/R group (both P < 0.05). Compared to H/R + negative control (NC) group, rate of cardiomyocyte apoptosis increased in H/R + miR-195 mimic group while decreased in H/R + miR-195 inhibitor group (both P <0.05). MiR-195 knockdown alleviated the loss of mitochondrial membrane potential (P <0.05). MiR-195 overexpression decreased Bcl-2 mRNA and protein expression, increased BaxmRNA and protein expression, Cyt-c protein expression and caspase-3 and caspase-9 activities (all P <0.05).While, downregulated MiR-195 increased Bcl-2 mRNA and protein expression, decreased Bax mRNA and protein expression, Cyt-c protein expression and caspase-3 and caspase-9 activities (all P < 0.05). Our study identified that miR-195 expression was upregulated in myocardial I/R injury, and miR-195 overexpression may promote cardiomyocyte apoptosis by targeting Bcl-2 and inducing mitochondrial apoptotic pathway.

Expression of Long Non-Coding RNA (lncRNA) Small Nucleolar RNA Host Gene 1 (SNHG1) Exacerbates Hepatocellular Carcinoma Through Suppressing miR-195

Background

Aberrant expression of lncRNA has been suggested to have an association with tumorigenesis. Our study was designed to reveal the underlying connection between lncRNA SNHG1 and hepatocellular carcinoma (HCC) pathogenesis.

Material/Methods

A total of 122 pairs of HCC tissues (case group) and matched adjacent non-tumor liver tissues (control group) were collected for this study. RT-PCR and in situ hybridization were conducted to investigate differences in lncRNA SNHG1 expression between the case and control group. The expression levels of lncRNA SNHG1 and miR-195 in HepG2 cells transfected with SNHG1-mimic and SNHG1-inhibitor were measured by RT-PCR. The proliferation, invasion, and migration status of HepG2 cells after transfection were assessed through MTT assay, wound healing assay, and Transwell assay, respectively. Whether miR-195 is a direct downstream target of lncRNA SNHG1 was verified by both bioinformatics target gene prediction and dual-luciferase report assay.

Results

The expression level of lncRNA SNHG1 was remarkably upregulated in HCC tissues and cell lines compared with normal tissues and cell lines. High expression of lncRNA SNHG1 contributed to the downregulation of miR-195 in HepG2 cells. Also, lncRNA SNHG1 exacerbated HCC cell proliferation, invasion, and migration in vitro through the inhibition of miR-195. This suggests that miR-195 is a direct downstream target of lncRNA SNHG1.

Conclusions

lncRNA SNHG1 may contribute to the aggravation of HCC through the inhibition of miR-195.

miR-195a inhibits adipocyte differentiation by targeting the preadipogenic determinator Zfp423

MicroRNAs (miRNAs) play essential roles in various cellular processes including proliferation and differentiation. In this study, we identified miRNA-195a (miR-195a) as a regulator of adipocyte differentiation. Differential expression of miR-195a in preadipocytes and adipocytes suggests its role in lipid accumulation and adipocyte differentiation. Forced expression of miR-195a mimics suppressed lipid accumulation and inhibited expression of adipocyte markers such as PPARγ and aP2 in 3T3-L1 and C3H10T1/2 cells. Conversely, downregulation of miR-195a by anti-miR-195a increased lipid accumulation and expression of adipocyte markers. Target prediction analysis suggested zinc finger protein 423 (Zfp423), a preadipogenic determinator, as a potential gene recognized by miR-195a. In line with this, mimicked expression of miR-195a reduced the expression of Zfp423, whereas anti-miR-195a increased its expression. Predicted targeting sequences in Zfp423 3'UTR, but not mutated sequences fused to luciferase, were regulated by miR-195a. Ectopic Zfp423 expression in 3T3-L1 cells increased lipid accumulation and expression of adipocyte markers, consistent with the observation that miR-195a targets Zfp423, resulting in suppressed adipocyte differentiation. In addition, miR-195a and Zfp423 were inversely correlated in obese fat tissues, raising the possibility of miRNA's role in obesity. Together, our data show that miR-195a is an anti-adipogenic regulator, which acts by targeting Zfp423, and further suggest the roles of miR-195a in obesity and metabolic diseases.

miR-15b-5p induces endoplasmic reticulum stress and apoptosis in human hepatocellular carcinoma, both in vitro and in vivo, by suppressing Rab1A

In human hepatocellular carcinoma (HCC), aberrant expression of miRNAs correlates with tumor cell proliferation, apoptosis, invasion, and migration by targeting downstream proteins. miR-15b levels are reported increased in HCC tissues; however, they negatively correlate to HCC recurrence. Our aim was to understand the reason for this phenomenon. We used the reverse transcription-polymerase chain reaction (RT-PCR) to measure miR-15b-5p expression in both HCC tissues and HCC cell lines. Our results were consistent with the report. Using bioinformatics and luciferase reporter assays, we identified Rab1A as a novel and direct target of miR-15b-5p. Inhibiting the function of Rab1A with shRab1A also inhibited the growth of HCC cells and induced endoplasmic reticulum stress (ERS) and apoptosis. Similarly, suppressing Rab1A by overexpression of miR-15b-5p also inhibited cell growth and induced ERS and apoptosis. Moreover, re-expression of Rab1A rescued the miR-15b-5p -induced ERS, apoptosis, and growth inhibition in HCC cells. In vivo assays were further performed to testify them. Taken together, our data suggest that miR-15b-5p induces ERS, apoptosis, and growth inhibition by targeting and suppressing Rab1A, acting as a tumor suppressor gene in HCC. This finding suggests a novel relation among Rabs, miRNAs, and apoptosis.

Dysregulated miRNA in progression of hepatocellular carcinoma: A systematic review

Hepatocellular carcinoma (HCC) is the fifth most frequent cancer and the third cause of cancer-related mortality worldwide. The primary risk factor for HCC is liver cirrhosis secondary to persistent infection with hepatitis B virus or hepatitis C virus. Although a number of cellular phenomena and molecular events have been reported to facilitate tumor initiation, progression and metastasis, the exact etiology of HCC has not yet been fully uncovered. miRNA, a class of non-coding RNA, negatively regulate post-transcriptional processes that participate in crucial biological processes, including development, differentiation, apoptosis and proliferation. In the liver, specific miRNA can be negative regulators of gene expression. Recent studies have uncovered the contribution of miRNA to cancer pathogenesis as they can function as oncogenes or tumor suppressor genes. In addition, other studies have demonstrated their potential value in the clinical management of patients with HCC as some miRNA may be used as prognostic or diagnostic markers. In this review, we summarize the current knowledge about the roles of miRNA in the carcinogenesis and progression of HCC.

Apoptosis-related microRNA changes in the right atrium induced by remote ischemic perconditioning during valve replacement surgery

We previously found that remote ischemic perconditioning (RIPerc) was effective in attenuating myocardial injury during cardiac surgery. Given that microRNAs (miRs) act as an important player in ischemic/reperfusion (I/R) injury and apoptosis, this study aimed to investigate whether RIPerc reduces apoptosis in atrial myocardium and which apoptosis-related miRs are involved during valve replacement surgery. Here, we demonstrated that RIPerc inhibited apoptosis in atrial myocardium during cardiac ischemia and that 17 miRs showed at least a 1.5-fold change in expression after ischemia. Of the 17 miRs, 9 miRs, including miR-1, miR-21, miR-24, and miR-195, which are related to apoptosis, exhibited different expression patterns in the RIPerc group compared with the control. Using qRT-PCR and Western blotting, we demonstrated that miR-1 and miR-195 were downregulated and that their common putative target gene Bcl-2 was upregulated in the RIPerc group. However, the differences in miR-21 and miR-24 expression, together with programmed cell death 4 (PDCD4), which is the target gene of miR-21, were not significant. These findings provide some insight into the role of miRs in the cardioprotective effects induced by RIPerc.

miR-195 Inhibits EMT by Targeting FGF2 in Prostate Cancer Cells

Prostate cancer (PCa) is one of the leading causes of deaths in America. The major cause of mortality can be attributed to metastasis. Cancer metastasis involves sequential and interrelated events. miRNAs and epithelial-mesenchymal transition (EMT) are implicated in this process. miR-195 is downregulated in many human cancers. However, the roles of miR-195 in PCa metastasis and EMT remain unclear. In this study, data from Memorial Sloan Kettering Cancer Center (MSKCC) prostate cancer database were re-analysed to detect miR-195 expression and its roles in PCa. miR-195 was then overexpressed in castration-resistant PCa cell lines, DU-145 and PC-3. The role of miR-195 in migration and invasion in vitro was also investigated, and common markers in EMT were evaluated through Western blot analysis. A luciferase reporter assay was conducted to confirm the target gene of miR-195; were validated in PCa cells. In MSKCC data re-analyses, miR-195 was poorly expressed in metastatic PCa; miR-195 could be used to diagnose metastatic PCa by measuring the corresponding expression. Area under the receiver operating characteristic curve (AUC-ROC) was 0.705 (P = 0.017). Low miR-195 expression was characterised with a shorter relapse-free survival (RFS) time. miR-195 overexpression suppressed cell migration, invasion and EMT. Fibroblast growth factor 2 (FGF2) was confirmed as a direct target of miR-195. FGF2 knockdown also suppressed migration, invasion and EMT; by contrast, increased FGF2 partially reversed the suppressive effect of miR-195. And data from ONCOMINE prostate cancer database showed that PCa patients with high FGF2 expression showed shorter RFS time (P = 0.046). Overall, this study demonstrated that miR-195 suppressed PCa cell metastasis by downregulating FGF2. miR-195 restoration may be considered as a new therapeutic method to treat metastatic PCa.

miR-195 is a key regulator of Raf1 in thyroid cancer

Proto-oncogene Raf1 serves as a part of the mitogen-activated protein kinases/extracellular signal-regulated kinase signal transduction pathway and regulates cell migration, apoptosis, and differentiation. Although a large number of studies have shown that Raf1 is overexpressed in various kinds of cancer, little is known about the association between Raf1 and miRNAs in thyroid carcinoma. This study proves that Raf1 is overexpressed in thyroid cancer, which has been confirmed by many other studies. Besides, we identify that Raf1 is a direct target of miR-15a/b, miR-16, and miR-195 by dual luciferase reporter assay. We also find that the expression of miR-195 is downregulated in 50 pairs of thyroid tumor tissues compared to the adjacent nontumor tissues, while there is no difference in the expression of miR-15a/b and miR-16 between the groups. Furthermore, exogenous overexpression of miR-195 significantly inhibits the protein expression of Raf1 and blocks the thyroid cancer cell proliferation. Our findings delineate a novel mechanism for the regulation of Raf1 in thyroid cancer, which may help to provide a new direction for the treatment of thyroid cancer.

HepatomiRNoma: The proposal of a new network of targets for diagnosis, prognosis and therapy in hepatocellular carcinoma

The diagnosis and treatment of hepatocellular carcinoma (HCC) underwent a huge advancement in the last years. Recently, microRNAs (miRNAs) have been also studied to provide a new tool for early diagnosis of high risk patients, for prognostic classification to identify those patients who benefit cancer treatment and for predictive definition to select the right targeted drug. In this review we revised all the available data obtained to explore the role of miRNAs in HCC. This analysis led to identification of miRNAs which could gain a diagnostic, prognostic or predictive role. The results of studies on miRNAs involved in HCC are initial and far from providing scientific evidences to translate into clinical practice. We propose a classification of these miRNAs, that we could name HepatomiRNoma as a whole. Anyway prospective studies have to be designed to clarify the real clinical impact of this new tool.

MicroRNAs involved with hepatocellular carcinoma (Review)

Hepatocellular carcinoma (HCC) is one of the most common malignancies, which accounts for 90% of primary liver cancer. HCC usually presents with poor outcomes due to the high rates of tumor recurrence and widespread metastasis. However, the underlying mechanism of HCC initiation and progression, which significantly hindered the development of valid approaches for early detection and treatment remain to be elucidated. As a group of small non-coding RNAs, microRNAs (miRNAs) have been demonstrated to be involved in many types of diseases especially human malignancies. Numerous miRNAs are deregulated in HCC, which may shed some light on current investigations. Since miRNAs are stable and detected easily, their ectopic expression has been reported in HCC tissues, serum/plasma and cell lines. As previously described, miRNAs serve as tumor suppressors or oncogenes, indicating that miRNAs may be useful as diagnostic, therapeutic and prognostic markers of HCC. In the present review, we assessed the latest data regarding dysregulated miRNAs in HCC and reviewed the reported functions of these miRNAs as they apply to the diagnosis and prognosis of HCC.

microRNA-195 inhibits the proliferation, migration and invasion of cervical cancer cells via the inhibition of CCND2 and MYB expression

The functions of microRNAs (miRNA/miR) in the development of cervical cancer remain largely undefined. The present study investigated the role of miR-195 in cervical cancer development. The expression of miR-195 mimics in the cervical cancer HeLa cell line significantly decreased the cell proliferation, migration and invasion capacities in vitro. Using miRNA target prediction algorithms and reporter assays, cyclin D2 (CCND2) and v-myb avian myeloblastosis viral oncogene homolog (MYB) were identified as direct targets of miR-195. Moreover, miR-195 repressed the expression of CCND2 and MYB in the HeLa cells at the mRNA and protein levels. Finally, the expression of miR-195 was downregulated in cervical cancer tissues compared with normal tissues. Together, these data suggest that miR-195 is a tumor suppressor in cervical cancer.