microRNA-29a suppresses cell proliferation by targeting SPARC in hepatocellular carcinoma

MiR-29a-laden extracellular vesicles efficiently induced apoptosis through autophagy blockage in HCC cells

BACKGROUND

In spite of significant advancements in theraputic modalities for hepatocellular carcinoma (HCC), there is still a high annual mortality rate with a rising incidence. Major challenges in the HCC clinical managment are related to the development of therapy resistance, and evasion of tumor cells apoptosis which leading unsatisfactory outcomes in HCC patients. Previous investigations have shown that autophagy plays crucial role in contributing to drug resistance development in HCC. Although, miR-29a is known to counteract authophagy, increasing evidence revealed a down-regulation of miR-29a in HCC patients which correlates with poor prognosis. Beside, evidences showed that miR-29a serves as a negative regulator of autophagy in other cancers. In the current study, we aim to investigate the impact of miR-29a on the autophagy and apoptosis in HCC cells using extracellular vesicles (EVs) as a natural delivery system given their potential in the miRNA delivery both in vitro and in vivo.

METHOD

Human Wharton's Jelly mesenchymal stromal cell-derived extracellular vesicles were lately isolated through 20,000 or 110,000 × g centrifugation (EV20K or EV110K, respectively), characterized by western blot (WB), scanning electron microscopy (SEM), and dynamic light scattering (DLS). miR-29a was subsequently loaded into these EVs and its loading efficiency was evaluated via RT-qPCR. Comprehensive in vitro and in vivo assessments were then performed on Huh-7 and HepG2 cell lines.

RESULTS

EV20K-miR-29a treatment significantly induces cell apoptosis and reduces both cell proliferation and colony formation in Huh-7 and HepG2 cell lines. In addition, LC3-II/LC3-I ratio was increased while the expression of key autophagy regulators TFEB and ATG9A were downregulated by this treatment. These findings suggest an effective blockade of autophagy by EV20K-miR-29a leading to apoptosis in the HCC cell lines through concomitant targeting of critical mediators within each pathway.

The role of SPARC (secreted protein acidic and rich in cysteine) in the pathogenesis of obesity, type 2 diabetes, and non-alcoholic fatty liver disease

Secreted protein acidic and rich in cysteine (SPARC) is an extracellular matrix glycoprotein with pleiotropic functions, which is expressed in adipose, hepatic, muscular, and pancreatic tissue. Particularly, several studies demonstrated that SPARC is an important player in the context of obesity, diabetes, and fatty liver disease including advanced hepatic fibrosis and hepatocellular carcinoma. Evidence in murine and human samples indicates that SPARC is involved in adipogenesis, cellular metabolism, extracellular matrix modulation, glucose and lipid metabolism, among others. Furthermore, studies in SPARC knockout mouse model showed that SPARC contributes to adipose tissue formation, non-alcoholic fatty liver disease (NAFLD), and diabetes. Hence, SPARC may represent a novel and interesting target protein for future therapeutic interventions or a biomarker of disease progression. This review summarizes the role of SPARC in the pathophysiology of obesity, and extensively revised SPARC functions in physiological and pathological adipose tissue deposition, muscle metabolism, liver, and diabetes-related pathways.

SPARC: a potential target for functional nanomaterials and drugs

Secreted protein acidic and rich in cysteine (SPARC), also termed osteonectin or BM-40, is a matricellular protein which regulates cell adhesion, extracellular matrix production, growth factor activity, and cell cycle. Although SPARC does not perform a structural function, it, however, modulates interactions between cells and the surrounding extracellular matrix due to its anti-proliferative and anti-adhesion properties. The overexpression of SPARC at sites, including injury, regeneration, obesity, cancer, and inflammation, reveals its application as a prospective target and therapeutic indicator in the treatment and assessment of disease. This article comprehensively summarizes the mechanism of SPARC overexpression in inflammation and tumors as well as the latest research progress of functional nanomaterials in the therapy of rheumatoid arthritis and tumors by manipulating SPARC as a new target. This article provides ideas for using functional nanomaterials to treat inflammatory diseases through the SPARC target. The purpose of this article is to provide a reference for ongoing disease research based on SPARC-targeted therapy.

MicroRNA-29a and MicroRNA-124 as novel biomarkers for hepatocellular carcinoma

BACKGROUND

Numerous microRNAs (miRNAs) have been observed to be abnormally expressed in cancer. Therefore, miRNA signatures could be potential noninvasive diagnostic and prognostic biomarkers for hepatocellular carcinoma (HCC).

AIMS

To correlate miRNA-29a and miRNA-124 expression levels with the clinical features and survival rates of HCC patients.

METHODS

Serum miRNA expression in 150 samples (50 patients with HCC, 50 patients with liver cirrhosis, and 50 healthy controls) were quantified using real-time qRT-PCR.

RESULTS

The expression levels of serum miRNA-29a were higher and the levels of miRNA-124 were lower in patients with HCC than in patients with liver cirrhosis and controls. ROC curve analysis showed promising accuracy for both miRNAs in distinguishing patients with HCC from those with liver cirrhosis. Levels of miRNA-29a were related to tumor number, size, stage, and outcome, whereas levels of miRNA-124 were related to vascular invasion. The overall survival rate of patients with low miRNA-29a expression was significantly higher than that of patients with high expression. Additionally, the multivariate analysis identified miRNA-29a as an independent prognostic variable.

CONCLUSIONS

The investigated miRNAs showed acceptable accuracy in the diagnosis of HCC; therefore, both could be utilized as diagnostic biomarkers. Additionally, miRNA-29a could be used as a prognostic biomarker.

The Role of miR-29s in Human Cancers—An Update

MicroRNAs (miRNAs) are small non-coding RNAs that directly bind to the 3’ untranslated region (3’-UTR) of the target mRNAs to inhibit their expression. The miRNA-29s (miR-29s) are suggested to be either tumor suppressors or oncogenic miRNAs that are strongly dysregulated in various types of cancer. Their dysregulation alters the expression of their target genes, thereby exerting influence on different cellular pathways including cell proliferation, apoptosis, migration, and invasion, thereby contributing to carcinogenesis. In the present review, we aimed to provide an overview of the current knowledge on the miR-29s biological network and its functions in cancer, as well as its current and potential applications as a diagnostic and prognostic biomarker and/or a therapeutic target in major types of human cancer.

Novel Methylation Biomarkers for Colorectal Cancer Prognosis

Colorectal cancer (CRC) comprises the third most common cancer worldwide and the second regarding number of deaths. In order to make a correct and early diagnosis to predict metastasis formation, biomarkers are an important tool. Although there are multiple signaling pathways associated with cancer progression, the most recognized are the MAPK pathway, p53 pathway, and TGF-β pathway. These pathways regulate many important functions in the cell, such as cell cycle regulation, proliferation, differentiation, and metastasis formation, among others. Changes in expression in genes belonging to these pathways are drivers of carcinogenesis. Often these expression changes are caused by mutations; however, epigenetic changes, such as DNA methylation, are increasingly acknowledged to play a role in the deregulation of oncogenic genes. This makes DNA methylation changes an interesting biomarkers in cancer. Among the newly identified biomarkers for CRC metastasis INHBB, SMOC2, BDNF, and TBRG4 are included, all of which are highly deregulated by methylation and closely associated with metastasis. The identification of such biomarkers in metastasis of CRC may allow a better treatment and early identification of cancer formation in order to perform better diagnostics and improve the life expectancy.

Modeling the Adsorption of the miR-29a Cancer Biomarker on a Graphene Quantum Dot

MicroRNAs (miRNAs) are small noncoding RNA molecules associated with the regulation of gene expression in organisms. MiRNAs are focused on as potential cancer biomarkers due to their involvement in cancer development. New potential techniques for miRNA detection are rapidly developed, while there is a lack of effective extraction approaches, especially for miRNAs. Recently, graphene quantum dots (GQDs) have been involved in many disease biosensor platforms including miRNA detection, but no application in miRNA extraction is studied. To extract miRNAs, miRNA adsorption and desorption on GQDs are the key. Thus, in this work, the adsorption mechanism of miRNA on GQDs in solution is revealed using molecular dynamics simulations. The aim is to explore the possibility of using GQDs for miRNA extraction. The folded miR-29a molecule, one of the key cancer biomarkers, is used as a miRNA model. Two systems with one (1miR) and four (4miR) chains of miR-29a were set. MiR-29a molecules in all systems are simultaneously adsorbed on the GQD surface. Our finding highlights the ability of the GQD in collecting miRNAs in solution. In 1miR, the whole miR-29a chain sits on the GQD face, whereas all miR-29a molecules in 4miR show the "clamping" conformation. No "lying flat" orientation of miR-29a is observed due to the existence of the preserved hairpin region. Interestingly, the 5' end shows tighter binding than the 3' terminus. A design of complementary DNA with the recognition segment involving the sequences close to the 3' end can promote effective miR-29a desorption.

lncRNA KCNQ1OT1 reverses the effect of sevoflurane on hepatocellular carcinoma progression via regulating the miR-29a-3p/CBX3 axis

Sevoflurane (SEVO) is widely applied as an anesthetic, which exerts antitumor capacity in various cancers, including hepatocellular carcinoma (HCC). Previous studies indicated that long non-coding RNA KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) was upregulated, while microRNA-29a-3p (miR-29a-3p) was downregulated in HCC. Thus, we aimed to explore the roles of KCNQ1OT1 and miR-29a-3p in HCC cells exposed to SEVO. Cell proliferation, apoptosis, migration, and invasion were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and transwell assays, respectively. The levels of genes were determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Furthermore, the interaction between miR-29a-3p and KCNQ1OT1 or chromebox protein homolog 3 (CBX3) was predicted by Starbase or Targetscan, and then confirmed by dual-luciferase reporter assay. We found that the levels of KCNQ1OT1 and CBX3 were decreased, while miR-29a-3p was increased in SEVO-treated HCC cells. KCNQ1OT1 overexpression weakened the inhibitory effects of SEVO on HCC cell proliferation, apoptosis, migration, and invasion. Interestingly, KCNQ1OT1 bound to miR-29a-3p, and miR-29a-3p targeted CBX3. KCNQ1OT1 upregulated CBX3 level by repressing miR-29a-3p expression. Furthermore, KCNQ1OT1 exerted tumor promotion in HCC cells via suppressing miR-29a-3p to regulate CBX3 expression. Collectively, our findings demonstrated that KCNQ1OT1 regulated the antitumor effects of SEVO on HCC cells through modulating the miR-29a-3p/CBX3 axis, providing a theoretical basis for the treatment of HCC.

New Insights into the Role of miR-29a in Hepatocellular Carcinoma: Implications in Mechanisms and Theragnostics

Hepatocellular carcinoma (HCC) remains one of the most lethal human cancer globally. For advanced HCC, curable plan for advanced HCC is yet to be established, and the prognosis remains poor. The detail mechanisms underlying the progression of HCC tumorigenicity and the corruption of tumor microenvironment (TME) is complex and inconclusive. A growing body of studies demonstrate microRNAs (miRs) are important regulators in the tumorigenicity and TME development. Notably, mounting evidences indicate miR-29a play a crucial role in exerting hepatoprotective effect on various types of stress and involved in the progression of HCC, which elucidates their potential theragnostic implications. In this review, we reviewed the advanced insights into the detail mechanisms by which miR-29a dictates carcinogenesis, epigenetic program, and metabolic adaptation, and implicated in the sponging activity of competitive endogenous RNAs (ceRNA) and the TME components in the scenario of HCC. Furthermore, we highlighted its clinical significance in diagnosis and prognosis, as well as the emerging therapeutics centered on the activation of miR-29a.

MicroRNAs in the Pathogenesis of Hepatocellular Carcinoma: A Review

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most frequently occurring cancers, and the prognosis for late-stage HCC remains poor. A better understanding of the pathogenesis of HCC is expected to improve outcomes. MicroRNAs (miRNAs) are small, noncoding, single-stranded RNAs that regulate the expression of various target genes, including those in cancer-associated genomic regions or fragile sites in various human cancers. We summarize the central roles of miRNAs in the pathogenesis of HCC and discuss their potential utility as valuable biomarkers and new therapeutic agents for HCC.

Abstract

Hepatocellular carcinoma (HCC) is the seventh most frequent cancer and the fourth leading cause of cancer mortality worldwide. Despite substantial advances in therapeutic strategies, the prognosis of late-stage HCC remains dismal because of the high recurrence rate. A better understanding of the etiology of HCC is therefore necessary to improve outcomes. MicroRNAs (miRNAs) are small, endogenous, noncoding, single-stranded RNAs that modulate the expression of their target genes at the posttranscriptional and translational levels. Aberrant expression of miRNAs has frequently been detected in cancer-associated genomic regions or fragile sites in various human cancers and has been observed in both HCC cells and tissues. The precise patterns of aberrant miRNA expression differ depending on disease etiology, including various causes of hepatocarcinogenesis, such as viral hepatitis, alcoholic liver disease, or nonalcoholic steatohepatitis. However, little is known about the underlying mechanisms and the association of miRNAs with the pathogenesis of HCC of various etiologies. In the present review, we summarize the key mechanisms of miRNAs in the pathogenesis of HCC and emphasize their potential utility as valuable diagnostic and prognostic biomarkers, as well as innovative therapeutic targets, in HCC diagnosis and treatment.

Omics Analysis of Educated Platelets in Cancer and Benign Disease of the Pancreas

Pancreatic ductal adenocarcinoma (PDAC) is traditionally associated with thrombocytosis/hypercoagulation and novel insights on platelet-PDAC "dangerous liaisons" are warranted. Here we performed an integrative omics study investigating the biological processes of mRNAs and expressed miRNAs, as well as proteins in PDAC blood platelets, using benign disease as a reference for inflammatory noise. Gene ontology mining revealed enrichment of RNA splicing, mRNA processing and translation initiation in miRNAs and proteins but depletion in RNA transcripts. Remarkably, correlation analyses revealed a negative regulation on SPARC transcription by isomiRs involved in cancer signaling, suggesting a specific "education" in PDAC platelets. Platelets of benign patients were enriched for non-templated additions of G nucleotides (#ntaG) miRNAs, while PDAC presented length variation on 3' (lv3p) as the most frequent modification on miRNAs. Additionally, we provided an actionable repertoire of PDAC and benign platelet-ome to be exploited for future studies. In conclusion, our data show that platelets change their biological repertoire in patients with PDAC, through dysregulation of miRNAs and splicing factors, supporting the presence of de novo protein machinery that can "educate" the platelet. These novel findings could be further exploited for innovative liquid biopsies platforms as well as possible therapeutic targets.

Circular RNA MYLK Promotes Hepatocellular Carcinoma Progression Through the miR29a/KMT5C Signaling Pathway

Purpose

This study aimed to investigate the functions of the circular RNA circMYLK (hsa_circ_0002768) in the development of hepatocellular carcinoma (HCC) and to identify the underlying mechanisms of the circMYLK/miR29a/KMT5C axis.

Materials and Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to explore the expressions of circMYLK, miR-29a and KMT5C in HCC tissues and cells. A potential miRNA (miR-29a) regulated by circMYLK was also explored, and the target relationship between miR-29a and KMT5C was confirmed. FISH, qRT-PCR, Western blotting, and dual-luciferase reporter assays were used to examine the circMYLK/miR29a/KMT5C signaling pathways involved in HCC development. Additionally, HCC cells were implanted into nude mice subcutaneously to test the role of circMYLK in tumor growth.

Results

circMYLK was determined to be significantly upregulated in HCC tissues and cells. Suppression of circMYLK repressed HCC cell proliferation, migration, and invasion while increasing apoptosis. In addition, FISH, qRT-PCR, and Western blotting, as well as dual-luciferase reporter assays, revealed that circMYLK could bind to miR-29a. In rescue experiments, miR-29a had the potential to eliminate the inhibitory effect of circMYLK knockdown in HCC. Moreover, miR-29a was found to target the KMT5C gene, which was positively regulated by circMYLK. Finally, a nude mouse tumorigenicity assay showed that injection of circMYLK siRNA into nude mice drastically suppressed xenograft tumor formation in vivo.

Conclusion

Our current study demonstrated that circMYLK promotes HCC progression by acting as a competing endogenous RNA of miR-29a, which regulates the downstream oncogene KMT5C.

Traditional Chinese Medicine Xiaoai Jiedu Recipe Suppresses the Development of Hepatocellular Carcinoma via Regulating the microRNA-29a/Signal Transducer and Activator of Transcription 3 Axis

Objective

Hepatocellular carcinoma (HCC) is one of the most frequent and lethal tumors affecting human health worldwide. The aim of this study was to investigate the anti-cancer effects of Xiaoai Jiedu Recipe (XJR) on HCC development and its underlying mechanisms.

Methods

The expression of microRNA-29a (miR-29a) and signal transducer and activator of transcription 3 (STAT3) in HCC tissues and cells was determined by quantitative real-time polymerase chain reaction. The proliferation, migration, and invasion of HCC cells were measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, wound-healing, and transwell assays, respectively. The regulatory relationship between miR-29a and STAT3 in HCC was predicted by TargetScan and analyzed by luciferase reporter and RNA pull-down assays. The protein expression of matrix metalloproteinase (MMP)-2/9 and STAT3 was detected by Western blotting. A xenograft tumor mouse model was established, and tumor weight and volume were measured.

Results

The expression of miR-29a was significantly decreased in HCC tissues and cells compared with that in normal tissues and cells. The up-regulation of miR-29a was related with lymph node metastasis and tumor node metastasis stage. XJR treatment significantly increased the expression of miR-29a, decreased cell viability, migration, and invasion, and reduced the protein expression of MMP-2/9 in HCC cells in a concentration-dependent manner. The anti-tumor effect of XJR on HCC cells was reversed by treatment with miR-29a inhibitor. STAT3 was predicted as a target of miR-29a, and its expression was negatively regulated by miR-29a. Moreover, STAT3 knockdown suppressed the malignant behavior of HCC cells, and its anti-tumor function was reversed by treatment with miR-29a inhibitor. Furthermore, XJR treatment inhibited tumor growth in mice through elevating miR-29a expression and inhibiting STAT3 expression.

Conclusion

XJR suppressed the development of HCC via regulating miR-29a and STAT3.

The Emerging Role of MicroRNAs in NAFLD: Highlight of MicroRNA-29a in Modulating Oxidative Stress, Inflammation, and Beyond

Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease and ranges from steatosis to steatohepatitis and to liver fibrosis. Lipotoxicity in hepatocytes, elevated oxidative stress and the activation of proinflammatory mediators of Kupffer cells, and fibrogenic pathways of activated hepatic stellate cells can contribute to the development of NAFLD. MicroRNAs (miRs) play a crucial role in the dysregulated metabolism and inflammatory signaling connected with NAFLD and its progression towards more severe stages. Of note, the protective effect of non-coding miR-29a on liver damage and its versatile action on epigenetic activity, mitochondrial homeostasis and immunomodulation may improve our perception of the pathogenesis of NAFLD. Herein, we review the biological functions of critical miRs in NAFLD, as well as highlight the emerging role of miR-29a in therapeutic application and the recent advances in molecular mechanisms underlying its liver protective effect.

MiR-29a regulates the proliferation, aromatase expression, and estradiol biosynthesis of human granulosa cells in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility in reproductive-aged women; however, its etiology remains poorly understood. This study aimed to reveal the role of miR-29a in PCOS. MiR-29a levels were measured in the granulosa cells (GCs) of forty-seven PCOS patients and forty-seven controls. A receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic value of miR-29a in non-hyperandrogenism PCOS. MiR-29a was overexpressed in KGN and COV434 cells to examine its roles in proliferation, cell-cycle progression, and steroidogenesis. MiR-29a was significantly down-regulated in PCOS patients, and associated with an increased antral follicle count. The ROC curve showed a major separation between PCOS patients and controls. MiR-29a overexpression in KGN and COV434 cells inhibited cell proliferation, arrested cell-cycle progression, and decreased aromatase expression and estradiol production. These findings suggest that miR-29a is involved in GC proliferation and steroidogenesis, providing insights into PCOS pathogenesis.

A comparative characterization of the circulating miRNome in whole blood and serum of HCC patients

miRNAs are considered promising non-invasive biomarkers. Serum represents the major source of biomarkers, being readily accessible for many analytical tests. Recently, whole blood has drawn increasing interest in biomarker studies due to the presence of cancer-interacting cells and circulating cancer cells. Although Hepatocellular Carcinoma (HCC) is the seventh most frequent cancer worldwide, fragmented information exists regarding the miRNome characterization in blood and serum. We profiled the circulatory miRNome of paired serum and blood samples from 20 HCC patients, identifying 274 miRNA expressed in serum and 670 in blood, most of them still uncharacterized. 157 miRNA significantly differ between the two biofluids with 28 exclusively expressed in serum. Six miRNA clusters significantly characterize the two compartments, with the cluster containing miR-4484, miR-1281, miR-3178, miR-3613-3p, miR-4532, miR-4668-5p, miR-1825, miR-4487, miR-455-3p, miR-940 having the highest average expression in serum compared to blood. The ontological analysis revealed a role of these miRNAs in cancer progression, vascular invasion and cancer immune surveillance thought the regulation of DUSP1, PD-L1 and MUC1. Taken together, these results provide the most comprehensive contribution to date towards a complete miRNome profile of blood and serum for HCC patients. We show a consistent portion of circulatory miRNAs being still unknown.

MicroRNA-29a Disrupts DNMT3b to Ameliorate Diet-Induced Non-Alcoholic Steatohepatitis in Mice

MicroRNA-29 (miR-29) has been found to reduce liver inflammation and fibrosis following a liver injury. Meanwhile, DNA methyltransferase has been reported to participate in the development of non-alcoholic steatohepatitis (NASH). The aim of this study is to investigate the miR-29a regulation of methyltransferase signaling and epigenetic program in NASH progression. Methods: miR-29a transgenic mice (miR-29aTg mice) and wild-type littermates were subjected to the methionine-choline-deficient (MCD) diet-induced animal model of NASH. Primary hepatic stellate cells were transfected with a miR-29a mimic and antisense inhibitor. We then analyzed gene expressions with qRT-PCR, immunohistochemical stain, Western blot, and luciferase reporter assay. The results demonstrated that increased miR-29a alleviated the MCD diet-induced body weight loss and steatosis and decreased aspartate aminotransferase (AST) levels in mice. Furthermore, hepatic tissue in miR-29aTg mice displayed a weak fibrotic matrix, as shown with Sirius Red staining concomitant with low fibrotic α-SMA expression within affected tissues compared to the wild-type mice fed the MCD diet. Forced miR-29a expression reduced the MCD diet exaggeration of reactive oxygen species (ROS) production by immunohistochemically staining 8-OHdG. Increased miR-29a signaling also resulted in the downregulation of DNMT3b, TGF-β, IL-6, heme oxygenase-1 (HO-1), p-SMAD3, PI3K, and L3BII expression within the liver tissue. An in vitro luciferase reporter assay further confirmed that miR-29a mimic transfection reduced DNMT3b expression in primary HSCs. Our data provide new insights that miR-29a improves MCD diet-induced liver inflammation, steatosis and fibrosis, and highlight the potential of miR-29a targeted therapy for treating NASH.

MicroRNA-29a activates a multi-component growth and invasion program in glioblastoma

Background

Glioblastoma is a malignant brain tumor characterized by rapid growth, diffuse invasion and therapeutic resistance. We recently used microRNA expression profiles to subclassify glioblastoma into five genetically and clinically distinct subclasses, and showed that microRNAs both define and contribute to the phenotypes of these subclasses. Here we show that miR-29a activates a multi-faceted growth and invasion program that promotes glioblastoma aggressiveness.

Methods

microRNA expression profiles from 197 glioblastomas were analyzed to identify the candidate miRNAs that are correlated to glioblastoma aggressiveness. The candidate miRNA, miR-29a, was further studied in vitro and in vivo.

Results

Members of the miR-29 subfamily display increased expression in the two glioblastoma subclasses with the worst prognoses (astrocytic and neural). We observed that miR-29a is among the microRNAs that are most positively-correlated with PTEN copy number in glioblastoma, and that miR-29a promotes glioblastoma growth and invasion in part by targeting PTEN. In PTEN-deficient glioblastoma cells, however, miR-29a nevertheless activates AKT by downregulating the metastasis suppressor, EphB3. In addition, miR-29a robustly promotes invasion in PTEN-deficient glioblastoma cells by repressing translation of the Sox4 transcription factor, and this upregulates the invasion-promoting protein, HIC5. Indeed, we identified Sox4 as the most anti-correlated predicted target of miR-29a in glioblastoma. Importantly, inhibition of endogenous miR-29a decreases glioblastoma growth and invasion in vitro and in vivo, and increased miR-29a expression in glioblastoma specimens correlates with decreased patient survival.

Conclusions

Taken together, these data identify miR-29a as a master regulator of glioblastoma growth and invasion.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1026-1) contains supplementary material, which is available to authorized users.

MicroRNA‑3653 inhibits the growth and metastasis of hepatocellular carcinoma by inhibiting ITGB1

microRNAs (miRNAs) play critical roles in hepatocellular carcinoma (HCC). However, the expression and biological function of miR-3653 in HCC remain unknown. The present study demonstrated that miR-3653 expression was significantly decreased in HCC tissues and cells using qRT-PCR. A decreased miR-3653 level was associated with unfavorable clinical features and poor prognosis of HCC patients. MTT, BrdU, Transwell and western blot assays showed that miR-3653 overexpression inhibited the growth, migration, invasion and epithelial-mesenchymal transition (EMT) of HCCLM3 cells while its knockdown promoted the growth and metastatic ability of Hep3B cells. In vivo experiments showed that miR-3653 overexpression inhibited the subcutaneous and the lung metastasis of HCCLM3 cells in nude mice. Mechanistically, integrin-β1 (ITGB1) was identified to be the downstream target of miR-3653 in HCC. ITGB1 overexpression reversed the inhibitory effects of miR-3653 on the growth, metastasis and EMT of HCCLM3 cells.

miR‑29a suppresses the growth and metastasis of hepatocellular carcinoma through IFITM3

The interferon-induced transmembrane protein 3 (IFITM3, also called 1-8U) gene represents dysregulated expression in various tumors and is involved in tumorigenesis and progression. However, the role of IFITM3 and its underlying mechanism in hepatocellular carcinoma (HCC) are still far from elucidated. MicroRNAs (miRNAs), a class of endogenous (approximately 22 nucleotides) small noncoding RNAs, can post-transcriptionally regulate gene expression by repressing protein translation or silencing the expression of target genes that play critical roles in various cancers. miR-29a was identified as being aberrantly expressed in a significant proportion of HCC. However, the correlation between IFITM3 and miR-29a has not been reported to date. In this study, we investigated the expression of IFITM3 in HCC and its effect on the biological behavior of HCC cells as well as the association between IFITM3 and miR-29a. We determined that IFITM3 was upregulated and miR-29a downregulated in HCC tissues and that they were associated with HCC tumor size, tumor multifocal, and venous invasion. The expression of IFITM3 in HCC tissues was negatively correlated with miR-29a expression. Additionally, IFITM3 overexpression and miR-29a nonoverexpression were related to poor prognosis of HCC patients. Knockdown of IFITM3 inhibited migration, invasion, proliferation and promoted apoptosis of HCC cells, which are consistent with the effects of upregulated miR-29a. Additionally, after upregulation of IFITM3, the invasion, migration and proliferation abilities of HL-7702 cells were increased, but the apoptosis rate was decreased. Furthermore, using a Dual-Luciferase reporter gene assay, we identified IFITM3 as a new functional target gene of miR-29a. In conclusion, our findings demonstrated that the migration, invasion, proliferation and apoptosis features of HCC cells could be regulated by miR-29a via IFITM3. Thus, the present study indicated that miR-29a and IFITM3 play critical roles in the development and progression of HCC, revealing that miR-29a and IFITM3 may be novel potential therapeutic targets for patients with HCC.

miR-129 inhibits tumor growth and potentiates chemosensitivity of neuroblastoma by targeting MYO10

Although the treatment strategies for neuroblastoma (NB) develop rapidly, a considerable number of patients could not benefit from chemotherapy. Here, we revealed a miR-129-MYO10 axis that regulated neuroblastoma growth and chemosensitivity. Mechanistically, MYO10 was up-regulated in neuroblastoma tissues and associated with poor overall survival. While overexpression of MYO10 enhanced tumor growth, genetic inhibition of MYO10 led to growth-inhibitory and chemopotentiating effects in neuroblastoma. MYO10 was further identified as a target of miR-129. Our data showed that miR-129 down-regulated MYO10 expression and subsequently suppressed cell growth. Re-expression of MYO10 significantly rescued miR129-mediated proliferation repression and chemosensitivity. In conclusion, our results demonstrated that miR-129 inhibited neuroblastoma growth and potentiated chemosensitivity by targeting MYO10, which may represent promising targets and rational therapeutic options for neuroblastoma.

Overexpression of miR-29a reduces the oncogenic properties of glioblastoma stem cells by downregulating Quaking gene isoform 6

Glioblastoma is the most common type of malignant primary brain tumor and has high recurrence and lethality rates. Glioblastoma stem cells (GSCs), a subpopulation of glioblastoma cells, may promote rapid tumor recurrence and therapy resistance. Because altered microRNA (miR) expression in GSCs may lead to glioblastoma progression, we assessed the effects of miR-29a expression on the oncogenic behavior of GSCs. MiR-29a expression was lower in GSCs than non-GSCs, and overexpression of miR-29a in GSCs inhibited cell proliferation, migration and invasion, but promoted apoptosis. MiR-29a directly inhibited the expression of Quaking gene isoform 6 (QKI-6) by binding to its 3'-UTR, and thus inhibited GSC malignant behavior. In addition, Wilms' tumor 1-associating protein (WTAP) was identified as a downstream target of QKI-6. Overexpression of miR-29a in GSCs inhibited expression of WTAP and suppressed both phosphoinositide 3-kinase/AKT and extracellular signal-related kinase pathways by downregulating QKI-6, thereby inhibiting cell proliferation, migration, and invasion but promoting apoptosis. We have characterized a novel miR-29a/QKI-6/WTAP axis in GSCs, which may provide theoretical support for the treatment of glioblastoma with miR-29a agomirs.

Serum microRNAs as predictors of risk for non-muscle invasive bladder cancer

MicroRNAs (miRNAs) are implicated in the development of nearly all cancers and may function as promising biomarkers for early detection, diagnosis and prognosis. We sought to investigate the role of serum miRNAs as potential diagnostic biomarkers or biomarkers of risk for early-stage bladder cancer. First, we profiled global serum miRNAs in a pilot set of 10 non-muscle invasive bladder cancer (NMIBC) cases and 10 healthy controls matched on age, gender and smoking status. Eighty nine stably detectable miRNAs were selected for further testing and quantification by high-throughput Taqman analysis using the Fluidigm BioMark HD System to assess their association with NMIBC risk in both discovery and validation sets totaling 280 cases and 278 controls. We found miR-409-3p and six miRNAs expression ratios were significantly associated with risk of bladder cancer in both discovery and validation sets. Interestingly, we identified expression of miR-409-3p and miR-342-3p inversely correlated with age and age of onset of NMIBC. A risk score was generated based on the combination of three miRNA ratios (miR-29a-3p/miR-222-3p, miR-150-5p/miR-331-3p, miR-409-3p/miR-423-5p). In dichotomized analysis, we found individuals with high risk score showed increased risk of bladder cancer in the discovery, validation, and combined sets. Pathway enrichment analyses suggested altered miRNAs and cognate target genes are linked to the retinoid acid receptor (RAR) signaling pathway. Overall, these results suggested specific serum miRNA signatures may serve as noninvasive predictors of NMIBC risk. Biological insights underlying bladder cancer development based on the pathway enrichment analysis may reveal novel therapeutic targets for personalized medicine.

MiR-29a: a potential therapeutic target and promising biomarker in tumors

MiRNAs, small non-coding RNA molecules, were recognized to be associated with the incidence and development of diverse neoplasms. MiRNAs were small non-coding RNAs that could regulate post-transcriptional level by binding to 3'-UTR of target mRNAs. Amongst which, miR-29a was demonstrated that it had significant impact on oncogenicity in various neoplasms through binding to critical genes which enhanced or inhibited the progression of cancers. MiR-29a participated in kinds of physiological and pathological processes, including virus replication, cell proliferation, differentiation, apoptosis, fibrosis, angiogenesis, tumorigenicity, metastasis, drug-resistance, and so on. According to its sufficient sensitivity and specificity, many studies showed that miR-29a might serve as a potential therapeutic target and promising biomarker in various tumors. In this review, we discussed the functions of miR-29a and its potential application in the diagnosis, treatment and stages of carcinoma, which could provide additional insight to develop a novel therapeutic strategy.

Plasma MicroRNA-21, 26a, and 29a-3p as Predictive Markers for Treatment Response Following Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma

BACKGROUND

We investigated an association between the levels of plasma microRNA (miRNA)-21, -26a, and -29a-3p and treatment outcomes following transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC).

METHODS

A total of 198 patients with TACE-treated HCC were followed up for TACE refractoriness and liver transplantation (LT)-free survival. Pretreatment plasma miRNA-21, -26a, and -29a-3p levels were measured using quantitative real-time polymerase chain reaction.

RESULTS

During the mean follow-up of 22.3 (range, 0.7-79) months, 118 (59.6%) patients exhibited TACE refractoriness. Multivariate analyses showed that expression of a specific combination of miRNAs (miRNA-21 ≥ 2.5, miRNA-26a ≥ 1.5, and miRNA-29a-3p < 0.4) was associated with early TACE refractoriness (within 1 year; hazard ratio [HR], 2.32; 95% confidence interval [CI], 1.08-4.99; P = 0.031) together with tumor size (HR, 4.62; 95% CI, 1.50-14.21; P = 0.008), and macrovascular invasion (HR, 3.80; 95% CI, 1.19-12.20; P = 0.025). However, miRNA-21, -26a, and -29a-3p levels were not significantly associated with overall TACE refractoriness or LT-free survival. Additionally, large tumor size and macrovascular invasion were common predictive factor of overall TACE refractoriness and survival.

CONCLUSION

Combination of plasma miRNA-21, -26a, and -29a-3p expression could predict early TACE refractoriness in patients with TACE-treated HCC.

MicroRNA-29a induces loss of 5-hydroxymethylcytosine and promotes metastasis of hepatocellular carcinoma through a TET-SOCS1-MMP9 signaling axis

Ten eleven translocation (TET) enzymes convert 5-methylcytosine (5-mC) to 5-hydroxy-methylcytosine (5-hmC) and have crucial roles in biological and pathological processes by mediating DNA demethylation, however, the functional role of this epigenetic mark and the related enzymes in hepatocellular carcinoma (HCC) progression remains unknown. Here, we demonstrated that TET-family enzymes downregulation was one likely mechanism underlying 5-hmC loss in HCC. We found that miR-29a overexpression increased DNA methylation of suppressor of cytokine signaling 1 (SOCS1) promoter was associated with HCC metastasis in vitro and in vivo. Furthermore, miR-29a silenced anti-metastatic SOCS1 through direct TET-family targeting, resulting in SOCS1 promoter demethylation inhibition. Chromatin immunoprecipitation analyses confirmed that TET1 regulated SOCS1 expression through binding to the promoter region of SOCS1. Finally, miR-29a overexpression correlated with poor clinical outcomes and TET-SOCS1-matrix metalloproteinase (MMP) 9 axis silencing in HCC patients. In conclusion, our findings demonstrate that 5-hmC loss is an epigenetic hallmark of HCC, and miR-29a is an important epigenetic modifier, promoting HCC metastasis through TET-SOCS1-MMP9 axis silencing. The results offer a new strategy for epigenetic cancer therapy.

MicroRNA-29a functions as a potential tumor suppressor through directly targeting CDC42 in non-small cell lung cancer

The expression and function of microRNA-29a (miR-29a) have been investigated in various types of cancer. In the present study, the expression, function and underlying molecular mechanism of miR-29a were investigated in non-small cell lung cancer (NSCLC). The expression level of miR-29a in NSCLC was determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, migration and invasion ability were determined using Cell Counting Kit-8, cell migration and invasion assays, respectively. Bioinformatics analysis and dual-luciferase reporter assays were performed to determine whether cell division cycle 42 (CDC42) is a direct target gene of miR-29a. To assess CDC42 mRNA and protein expression following transfection with miR-29a, RT-qPCR and western blotting were performed. Following knockdown of CDC42, functional assays were performed to investigate the roles of CDC42 in NSCLC. The results demonstrated that miR-29a was downregulated in NSCLC and the decreased expression level of miR-29a was significantly associated with advanced tumor-node-metastasis classification and metastasis. In addition, upregulation of miR-29a inhibited cell proliferation, migration and invasion in NSCLC, whereas downregulation of miR-29a had the opposite effects. Furthermore, CDC42 was identified as a direct target gene of miR-29a in vitro. miR-29a was demonstrated to function as a tumor suppressor in NSCLC by directly targeting CDC42 and may be investigated further as a target therapy for NSCLC.

Low levels of circulating microRNA-26a/29a as poor prognostic markers in patients with hepatocellular carcinoma who underwent curative treatment

BACKGROUND/AIMS

We evaluated the prognostic implication of circulating microRNA (miR)-21, miR-26a, and miR-29a in hepatocellular carcinoma (HCC) patients who underwent curative treatment.

METHODS

The study included 120 hepatitis B virus-related HCC patients who underwent hepatic resection (n=63) or radiofrequency ablation (n=57). MiR-21, miR-26a, and miR-29a expression levels in pretreatment plasma and several clinical variables were analyzed to identify prognostic bio-markers.

RESULTS

Old age, low albumin level, low platelet count, advanced tumor stage (modified Union for International Cancer Control stages III, IV), low miR-26a (hazard ratio [HR]=1.72; 95% confidence interval [CI]=1.04-2.83; P=0.035), and low miR-29a (HR=1.75; 95% CI=1.04-2.94; P=0.035) were identified as independent risk factors for predicting poor disease-free survival. Low miR-21, miR-26a, and miR-29a were associated with poor liver transplantation (LT)-free survival in the univariate analysis. Multivariate Cox regression analysis showed that low miR-26a (HR=3.41; 95% CI=1.32-8.82; P=0.011) and low miR-29a (HR=2.75; 95% CI=1.10-6.85; P=0.030), low platelet count, and advanced tumor stage were significantly associated with poor LT-free survival. Remarkable correlation was found between miR-26a and miR-29a (Spearman's rho=0.734, P<0.001).

CONCLUSION

Pretreatment levels of circulating miR-26a and miR-29a are independent prognostic markers for poor disease-free survival and LT-free survival in hepatitis B virus-related HCC patients.

Knockdown of KLK11 inhibits cell proliferation and increases oxaliplatin sensitivity in human colorectal cancer

It has been reported that kallikrein 11 (KLK11) is crucially involved in the development and progression of various types of cancer. However, the molecular mechanisms that underlie the involvement of KLK11 in aberrant colorectal cancer (CRC) cell growth remain largely unclear. The aim of the present study was to investigate the role of KLK11 and the effects of KLK11 on oxaliplatin (L-OHP) chemosensitivity by knocking down KLK11 in LOVO and HCT-8 cells. Loss-of-function assays revealed KLK11 inhibition significantly inhibited growth and induced apoptosis of CRC cells in vitro. Notably, further experiments found that knockdown of KLK11 expression increased the L-OHP chemosensitivity of CRC cells. KLK11 inhibition of increased L-OHP-induced apoptosis may be associated with activation of caspase-3 cleavage and the apoptosis signaling pathway. The present results indicated that KLK11 may be an potential target of interest for future research into therapies for CRC.

MiRNA-203 suppresses cell proliferation, migration and invasion in colorectal cancer via targeting of EIF5A2

While it is known that miR-203 is frequently downregulated in many types of human cancer, little is known regarding its expression and functional role in colorectal cancer (CRC). In this study, we aimed to investigate the expression and the potential mechanisms of miR-203 in colorectal cancer. MiR-203 was significantly downregulated in CRC tissues compared with matched normal adjacent tissues. Our clinical data show that decreased miR-203 was associated with an advanced clinical tumor-node-metastasis stage, lymph node metastasis, and poor survival in CRC patients. Furthermore, externally induced expression of miR-203 significantly inhibited CRC cell proliferation and invasion in vitro and in vivo. Mechanistically, we identified EIF5A2 as a direct and functional target of miR-203. The levels of miR-203 were inversely correlated with levels of the EIF5A2 in the CRC tissues. Restoration of EIF5A2 in the miR-203-overexpressing CRC cells reversed the suppressive effects of miR-203. Our results demonstrate that miR-203 serves as a tumor suppressor gene and may be useful as a new potential therapeutic target in CRC.

MiRNA-211 suppresses cell proliferation, migration and invasion by targeting SPARC in human hepatocellular carcinoma

Previous studies have shown that the expression of miR-211 was downregulated in hepatocellular carcinoma (HCC). However, the molecular function and mechanism of miR-211 in HCC growth and invasion are largely unclear. We found that miR-211 is downregulated in HCC tissues and cell lines, respectively. Further results showed that low miR-211 associated with TNM stage, vein invasion status, and poor prognosis. Ectopic expression of miR-211 effectively suppressed HCC cell proliferation, migration and invasion both in vitro and in vivo. We identified SPARC as a bona fide target of miR-211, and overexpression of miR-211 decreased the mRNA and protein expression of SPARC. Finally, we confirmed that the overexpression of SPARC in miR-211-expressing HCC cells can partially restore the inhibitory effect of miR-211. Taken together, our results demonstrated that loss of miR-211 expression and thus uncontrolled SPARC overexpression might drive progression of HCC, which may provide a novel therapeutic strategy for the treatment of HCC.

The 'SPARC' of life: Analysis of the role of osteonectin/SPARC in pancreatic cancer (Review)

Pancreatic ductal adenocarcinoma (PDAC) is one of the most clinically challenging cancers to manage. An estimated 48,960 people will be diagnosed with pancreatic cancer in 2015, of that population, 94% are projected to perish within 5 years. These dismal survival rates can be attributed, in part, to an advanced diagnosis occurring in 80% of cases. The heterogeneous and dynamic microenvironment of pancreatic cancer, and the lack of both specific risk factors and efficacious screening tools contribute to the challenge of diagnosing pancreatic cancer in its early stages. These clinical challenges have directed research into the unique characteristics that define PDAC. Recently, there has been an increased focus on the interaction of tumor cells with their microenvironment in the hope of identifying new therapeutic targets. One of the most promising avenues in this new vein of research is targeting protein communication between the cancer cells and the extracellular matrix. The secreted protein acidic and rich in cysteine (SPARC) is one such extracellular matrix protein that has shown potential as a therapeutic target due to its influence on PDAC invasion and metastasis. In this review, we discuss the complex interaction of SPARC with PDAC cells and its potential to guide treatment and eventually improve the survival of patients diagnosed with this devastating disease.

MicroRNA-let-7f-1 is induced by lycopene and inhibits cell proliferation and triggers apoptosis in prostate cancer

Previous studies have suggested that lycopene has cytotoxic effects in a variety of types of human cancer. An improved understanding of the mechanisms underlying the anticancer effects of lycopene may provide novel therapeutic targets for cancer treatment. PC3 cells were treated with different concentrations of lycopene for 24 and 48 h, the level of protein kinase B (AKT2) was detected by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blotting. Additionally, the expression levels of microRNA (miR)‑let‑7f‑1 were measured using RT‑qPCR. miR‑let‑7f‑1 function was analyzed using cell proliferation and apoptosis assays in gain‑ and loss‑of‑function experiments. It was observed that lycopene downregulated the expression of AKT2 and upregulated the expression of miR‑let‑7f‑1 in PC3 cells. Re‑introduction of miR‑let‑7f‑1 into PC3 cells was able to inhibit cell proliferation and induce apoptosis. Further investigation indicated that miR‑let‑7f‑1 targeted AKT2 in PC3 cells and upregulation of AKT2 could attenuate the effects induced by miR‑let‑7f‑1. The results of the current study indicate that miR‑let‑7f‑1 is involved in the anticancer effects of lycopene and serves an important role in the inhibition of prostate cancer progression through the downregulation of AKT2.

Coordinate regulation of microenvironmental stimuli and role of methylation in bone metastasis from breast carcinoma

The pathogenesis of bone metastasis is unclear, and much focus in metastatic biology and therapy relays on epigenetic alterations. Since DNA-methyltransferase blockade with 5-aza-2'-deoxycytidine (dAza) counteracts tumour growth, here we utilized dAza to clarify whether molecular events undergoing epigenetic control were critical for bone metastatization. In particular, we investigated the patterns of secreted-protein acidic and rich in cysteine (SPARC) and of Endothelin 1, affected by DNA methyltransferases in tumours, with the hypothesis that in bone metastasis a coordinate function of SPARC and Endothelin 1, if any occurs, was orchestrated by DNA methylation. To this purpose, we prepared a xenograft model with the clone 1833, derived from human-MDA-MB231 cells, and dAza administration slowed-down metastasis outgrowth. This seemed consequent to the reductions of SPARC and Endothelin 1 at invasive front and in the bone marrow, mostly due to loss of Twist. In the metastasis bulk Snail, partly reduced by dAza, might sustain Endothelin 1-SPARC cooperativity. Both SPARC and Endothelin 1 underwent post-translational control by miRNAs, a molecular mechanism that might explain the in vivo data. Ectopic miR29a reduced SPARC expression also under long-term dAza exposure, while Endothelin 1 down-regulation occurred in the presence of endogenous-miR98 expression. Notably, dAza effects differed depending on in vivo and in vitro conditions. In 1833 cells exposed to 30-days dAza, SPARC-protein level was practically unaffected, while Endothelin 1 induction depended on the 3'-UTR functionality. The blockade of methyltransferases leading to SPARC reduction in vivo, might represent a promising strategy to hamper early steps of the metastatic process affecting the osteogenic niche.

Tissue microRNA-126 expression level predicts outcome in human osteosarcoma

Background

MicroRNA-126 has been found to be consistently under-expressed in osteosarcoma tissues and cell lines compared with normal bone tissues and normal osteoblast cells, respectively. The purpose of the present study was to detect the expression levels of miR-126 in osteosarcoma patients and to further investigate the clinicopathological, and prognostic value of miR-126.

Methods

We recruited 122 patients with osteosarcomas from the Department of Orthopedic Surgery, Yantaishan Hospital between May 2008 and April 2013. The expression level of miR-126 was determined by qRT-PCR. Associations between miR-126 expression and various clinicopathological characteristics were analyzed using the χ² test. Survival rate was determined with Kaplan-Meier and statistically analyzed with the log-rank method between groups. Survival data were evaluated through multivariate Cox regression analysis.

Results

miR-126 expression was significantly decreased in osteosarcoma tissues compared to adjacent normal bone tissues (2.421 ± 1.250 vs. 6.212 ± 1.843, P = 0.001). We found that low miR-126 expression had significant association with advanced TNM stage (P <0.001), distant metastasis (P <0.001), and higher tumor grade (P = 0.001). Kaplan-Meier survival analysis showed that the miR-126 low-expression group had significantly shorter overall survival time than those with high-expression (log-rank test, P = 0.008). Furthermore, multivariate Cox proportional hazards model analysis showed that miR-126 expression was independently associated with overall survival of patients with osteosarcoma (HR = 3.102, 95 % CI: 1.113–9.023, P = 0.018).

Conclusions

This is the first study revealing that miR-126 down-expression may be related to the prediction of poor prognosis for osteosarcoma patients, suggesting that miR-126 may serve as a prognostic marker for the optimization of clinical treatments.

Role of gelsolin in cell proliferation and invasion of human hepatocellular carcinoma cells

OBJECTIVE

Gelsolin (GSN), one of the most important actin structure regulating proteins, has been implicated in the oncogenesis of some cancers. In this study, we investigated the expression of GSN in hepatocellular carcinoma (HCC) and revealed its potential mechanisms. The mRNA and protein levels of GSN were overexpressed in HCC cells and HCC tissues compared to adjacent noncancerous tissues. GSN expression was correlated with venous invasion (P=0.0199) and Edmonson grading (P=0.0344) expression in HCC. Overexpression of GSN in Huh7 and SMMC-7721 cells significantly promoted cell proliferation and the number of Matrigel™-invading cells compared with control cells, with increased expression of matrix metalloproteinase MCL-1, MMP-2 and MMP-9, a key regulator of growth and invasion. In contrast, knockdown of GSN expression with small interfering RNA (siRNA) in MHCC-97L and MHCC-97H cell lines resulted in decreased cell viability and cell invasion. Our findings indicated that GSN expression promoted tumor-associated phenotypes by facilitating proliferative and invasive capacities of HCC cells, which might serve as a potential therapeutic target for HCC treatment.

MicroRNAs dysregulation in hepatocellular carcinoma: Insights in genomic medicine

Hepatocellular carcinoma (HCC) is the leading primary liver cancer and its clinical outcome is still poor. MicroRNAs (miRNAs) have demonstrated an interesting potential to regulate gene expression at post-transcriptional level. Current findings suggest that miRNAs deregulation in cancer is caused by genetic and/or epigenetic, transcriptional and post-transcriptional modifications resulting in abnormal expression and hallmarks of malignant transformation: aberrant cell growth, cell death, differentiation, angiogenesis, invasion and metástasis. The important role of miRNAs in the development and progression of HCC has increased the efforts to understand and develop mechanisms of control overt this single-stranded RNAs. Several studies have analyzed tumoral response to the regulation and control of deregulated miRNAs with good results in vitro and in vivo, proving that targeting aberrant expression of miRNAs is a powerful anticancer therapeutic. Identification of up and/or down regulated miRNAs related to HCC has led to the discovery of new potential application for detection of their presence in the affected organism. MiRNAs represent a relevant new target for diagnosis, prognosis and treatment in a wide variety of pathologic entities, including HCC. This manuscript intends to summarize current knowledge regarding miRNAs and their role in HCC development.

MicroRNA Expression Profiling in Clear Cell Renal Cell Carcinoma: Identification and Functional Validation of Key miRNAs

OBJECTIVE

This study aims to profile dysregulated microRNA (miRNA) expression in clear cell renal cell carcinoma (ccRCC) and to identify key regulatory miRNAs in ccRCC.

METHODS AND RESULTS

miRNA expression profiles in nine pairs of ccRCC tumor samples at three different stages and the adjacent, non-tumorous tissues were investigated using miRNA arrays. Eleven miRNAs were identified to be commonly dysregulated, including three up-regulated (miR-487a, miR-491-3p and miR-452) and eight down-regulated (miR-125b, miR-142-3p, miR-199a-5p, miR-22, miR-299-3p, miR-29a, miR-429, and miR-532-5p) in tumor tissues as compared with adjacent normal tissues. The 11 miRNAs and their predicted target genes were analyzed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and three key miRNAs (miR-199a-5p, miR-22 and miR-429) were identified by microRNA-gene network analysis. Dysregulation of the three key miRNAs were further validated in another cohort of 15 ccRCC samples, and the human kidney carcinoma cell line 786-O, as compared with five normal kidney samples. Further investigation showed that over-expression of miR-199a-5p significantly inhibited the invasion ability of 786-O cells. Luciferase reporter assays indicated that miR-199a-5p regulated expression of TGFBR1 and JunB by directly interacting with their 3' untranslated regions. Transfection of miR-199a-5p successfully suppressed expression of TGFBR1 and JunB in the human embryonic kidney 293T cells, further confirming the direct regulation of miR-199a-5p on these two genes.

CONCLUSIONS

This study identified 11 commonly dysregulated miRNAs in ccRCC, three of which (miR-199a-5p, miR-22 and miR-429) may represent key miRNAs involved in the pathogenesis of ccRCC. Further studies suggested that miR-199a-5p plays an important role in inhibition of cell invasion of ccRCC cells by suppressing expression of TGFBR1 and JunB.

miR-29a/b enhances cell migration and invasion in nasopharyngeal carcinoma progression by regulating SPARC and COL3A1 gene expression

Nasopharyngeal carcinoma (NPC) is a malignant tumor associated with a genetic predisposition, Epstein-Barr virus infection and chromosomal abnormalities. Recently, several miRNAs have been shown to target specific mRNAs to regulate NPC development and progression. However, the involvement of miRNAs in processes leading to NPC migration and invasion remains to be elucidated. We predicted that miR-29a/b are associated with dysregulated genes controlling NPC through an integrated interaction network of miRNAs and genes. miR-29a/b over-expression in NPC cell lines had no significant effect on proliferation, whereas miR-29b mildly increased the percentage of cells in the G1 phase with a concomitant decrease in the percentage of cells in S phase. Furthermore, we demonstrated that miR-29a/b might be responsible for increasing S18 cell migration and invasion, and only COL3A1 was identified as a direct target of miR-29b despite the fact that both SPARC and COL3A1 were inhibited by miR-29a/b over-expression. Meanwhile, SPARC proteins were increased in metastatic NPC tissue and are involved in NPC progression. Unexpectedly, we identified that miRNA-29b expression was elevated in the serum of NPC patients with a high risk of metastasis. The 5-year actuarial overall survival rates in NPC patients with high serum miR-29b expression was significantly shorter than those with low serum miR-29b expression; therefore, serum miR-29b expression could be a promising prognostic marker.

MLK3 promotes melanoma proliferation and invasion and is a target of microRNA-125b

BACKGROUND

Metastatic melanoma is a disease with high mortality and limited therapeutic options. MicroRNAs (miRNAs) can be used to classify melanoma stage.

METHODS

Expression of the miRNA miR-125b and serine/threonine kinase mixed lineage kinase (MLK)3 was assessed in primary malignant melanoma tissues and several melanoma cell lines by quantitative reverse transcription PCR. The effect of MLK3 and miR-125b on cell proliferation was evaluated by MTS assay, and cell invasion was evaluated by Transwell invasion assays. Targeting of MLK3 by miR-125b was evaluated using luciferase reporter assay and western blotting.

RESULTS

We found significantly increased levels of MLK3 in metastatic primary malignant melanomas and melanoma cell lines, with levels being especially high in metastatic lines. To investigate the functional significance of MLK3, we used knockdown MLK3, which was found to suppress cell growth and invasion. Using bioinformatics, we identified MLK3 as one potential target of miR-125b. miRNA transfection and luciferase assay confirmed that MLK3 was regulated by miR-125b at both the transcriptional and translational levels. Cell proliferation and cell invasion was inhibited by overexpression of miR-125b.

CONCLUSIONS

MLK3 is upregulated in metastatic melanoma, and regulates cell proliferation and invasion in melanoma cells. MLK3 is a direct target of miR-125b.

miRNA in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. Despite improvements in HCC therapy, the prognosis for HCC patients remains poor due to a high incidence of recurrence. An improved understanding of the pathogenesis of HCC development would facilitate the development of more effective outcomes for the diagnosis and treatment of HCC at earlier stages. miRNA are small, endogenous, non-coding, ssRNA that are 21-30 nucleotides in length and modulate the expression of various target genes at the post-transcriptional and translational levels. Aberrant expression of miRNA is common in various human malignancies and modulates cancer-associated genomic regions or fragile sites. As for the relationship between miRNA and HCC, several studies have demonstrated that the aberrant expression of specific miRNA can be detected in HCC cells and tissues. However, little is known about the mechanisms of miRNA-related cell proliferation and development. In this review, we summarize the central and potential roles of miRNA in the pathogenesis of HCC and elucidate new possibilities that may be useful as diagnostic and prognostic markers, as well as novel therapeutic targets in HCC.

MiR-451 inhibits cell growth and invasion by targeting CXCL16 and is associated with prognosis of osteosarcoma patients

Recent studies have shown that microRNA-451 (miR-451) was significantly decreased in osteosarcoma tissues and was identified as a tumor suppressor in other types of human cancers. However, its clinical significance and molecular mechanisms in osteosarcoma are still not well understood. MiR-451 levels are evaluated by quantitative reverse transcription-polymerase chain reaction (RT-PCR) in osteosarcoma cell lines and in 68 pairs of osteosarcoma and adjacent noncancerous tissues. Then, the associations of miR-451 expression with clinicopathological features of patients were determined. The effects of miR-451 in osteosarcoma cells were examined by MTT and Matrigel invasion assay. The functional target of miR-451 were determined by bioinformatics analysis and validated by luciferase reporter analyses and Western blot assay. Our results showed that the expression of miR-451 was significantly downregulated in osteosarcoma tissues compared with corresponding noncancerous tissues (P < 0.01). Particularly, statistical analysis of primary human osteosarcoma indicated that decreased expression of miR-451 was correlated with metastasis and recurrence. Moreover, the miR-451 force-expression suppressed cell proliferation and invasion in vitro. Based on bioinformatics analysis, we found that chemokine ligand 16 (CXCL16) was identified as a direct functional target of miR-451. Consistent with the effects of miR-451, silencing CXCL16 could phenocopy the effects of miR-451 on phenotypes of osteosarcoma cells. Furthermore, CXCL16 expression was upregulated in osteosarcoma tissues and inversely associated with miR-451 in human osteosarcoma tissues. Our data reveal a downregulated expression of miR-451 in osteosarcoma tissues, which is inversely associated with CXCL16 levels. These observations demonstrated that miR-451 may play an important role in tumor growth and metastasis in osteosarcoma.

miR-29a activates Hes1 by targeting Nfia in esophageal carcinoma cell line TE-1

MicroRNA (miR)-29a has been associated with carcinogenesis in humans; however, its functional significance in esophageal squamous cell carcinoma (ESCC) is yet to be determined. In the present study, the expression of miR-29a was markedly downregulated in ESCC tissue and the ESCC TE-1 cell line, compared with normal esophageal tissue and cells. Furthermore, the present study identified that the forced expression of miR-29a in TE-1 cells significantly reduced cell proliferation and migration. miR-29a overexpression did not affect the expression of Notch1, however, it did increase the gene expression levels of hairy and enhancer of split 1 (Hes1), which is the key effector of the Notch signaling pathway. Direct targeting by miR-29a resulted in the downregulation of nuclear factor 1 A (Nfia), which represses the transcriptional activity of the Hes1 promoter. Furthermore, knockdown of Nfia increased Hes1 expression and inhibited cell growth in TE-1 cells. These results indicate that a low level of miR-29a expression is involved in ESCC tumorigenesis, and exogenous expression of miR-29a may repress cancer cell growth by downregulating Nfia and activating the Notch signaling pathway.

Re-sensitization of 5-FU resistance by SPARC through negative regulation of glucose metabolism in hepatocellular carcinoma

Secreted protein, acidic and rich in cysteine (SPARC), a calcium-binding matricellular glycoprotein, is implicated in the progression of many cancers. Currently, there is growing evidence for important functions of SPARC in a variety of cancers and its role in cancer depends on tumor types. In this study, we reported SPARC negatively regulated glucose metabolism in hepatocellular carcinoma (HCC). Overexpression of SPARC inhibited glucose uptake and lactate product through downregulation of key enzymes of glucose metabolism. On the other hand, knock down of SPARC reversed the phenotypes. Meanwhile, exogenous expression of SPARC in HepG2 cells resulted in tolerance to low glucose and was correlated with AMPK pathway. Interestingly, the 5-fluorouracil (5-FU)-resistant HepG2 cells showed increased glucose metabolism and downregulated SPARC levels. Finally, we reported the overexpression of SPARC re-sensitize 5-FU-resistant cells to 5-FU through inhibition of glycolysis both in vitro and in vivo. Our study proposed a novel function of SPARC in the regulation of glucose metabolism in hepatocellular carcinoma and will facilitate the development of therapeutic strategies for the treatments of liver tumor patients.

The role of miR-29 in pulmonary fibrosis

Pulmonary fibrosis is a pathological condition in which lungs become scarred due to the excess extracellular matrix (ECM) deposition and structural alterations in the interstitium of lung parenchyma. Many patients with interstitial lung diseases (ILDs) caused by long-term exposure to toxic substances, chronic infections, or autoimmune responses develop fibrosis. Etiologies for many ILDs are unknown, such as idiopathic pulmonary fibrosis (IPF), a devastating, relentless form of pulmonary fibrosis with a median survival of 2-3 years. Despite several decades of research, factors that initiate and sustain the fibrotic response in lungs remain unclear and there is no effective treatment to block progression of fibrosis. Here we summarize recent findings on the antifibrotic activity of miR-29, a small noncoding regulatory RNA, in the pathogenesis of fibrosis by regulating ECM production and deposition, and epithelial-mesenchymal transition (EMT). We also describe interactions of miR-29 with multiple profibrotic and inflammatory pathways. Finally, we review the antifibrotic activity of miR-29 in animal models of fibrosis and highlight miR-29 as a promising therapeutic reagent or target for the treatment of pulmonary fibrosis.