MicroRNA-133a Regulates the Viability and Differentiation Fate of Bone Marrow Mesenchymal Stem Cells via MAPK/ERK Signaling Pathway by Targeting FGFR1

Dysfunction of bone marrow mesenchymal stem cells (BMSCs) is recognized critical in bone deteriorations of osteoporosis. However, the specific mechanisms that determine the fate of BMSCs remain elusive. MicroRNA-133a (miR-133a), a highly conserved microRNA, was investigated under both in vitro and in vivo conditions. In the in vitro study, cell proliferation, cell apoptosis, and osteoblast/adipocyte differentiation of BMSCs as a result of overexpression or knockdown of miR-133a was investigated. In the in vivo study, the ovariectomy (OVX) model was applied on mice, with further treatment of the models with BMSC-specific miR-133a antagomir through femur intramedullary injection. Microcomputed tomography scanning and histological analysis of the proximal and middle femur were performed to evaluate the morphological changes. The results revealed that overexpression of miR-133a suppressed cell proliferation, cell viability, and osteoblast differentiation of BMSCs, but increased adipocyte differentiation. We also found that FGFR1, an important upstream regulator of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signal pathway, was a major target of miR-133a. We also recorded that BMSC-specific knockdown of miR-133a attenuates bone loss in OVX mice. Our study suggested that miR-133a played an important role in maintaining the viability and balance between osteoblast and adipocyte differentiation of BMSCs through the MAPK/ERK signaling pathway by targeting FGFR1.

miR-133a silencing rescues glucocorticoid-induced bone loss by regulating the MAPK/ERK signaling pathway

BACKGROUND

Dysfunction of mesenchymal stem cells (MSCs) is recognized as critical to the pathogenesis of glucocorticoid-induced osteoporosis (GIO), suggesting the potential of MSC-targeting interventions for this disorder. As the miR-133a has been shown to play an important role in bone metabolism, we hypothesized that miR-133a may also be involved in GIO.

METHODS

In the in vitro study, we examined the effect of miR-133a antagomir on DEX-treated MSCs, including proliferation, apoptosis, osteoblast, and adipocyte differentiation, then, we explored the mechanism of these effects of miR-133a silencing through measuring the phosphorylation of ERK1/2 and its regulator FGFR1 via western blot and qRT-PCR. In the in vivo study, we developed a GIO rat model by injecting methylprednisolone and modulated the miR-133a expression in the femur by intramedullary injection of the miR-133a antagomir, and then micro-CT analyses and histological staining of the femurs were used to investigate the effect of miR-133a silencing on bone loss of the GIO rats.

RESULTS

qRT-PCR analysis indicated that glucocorticoid induced high miR-133a expression in MSCs and animal models. The in vitro study showed that miR-133a antagomir significantly promoted cell proliferation, viability, and osteoblast differentiation and inhibited adipocyte differentiation in DEX-treated MSCs. Furthermore, the expression of p-ERK1/2 and FGFR1 in DEX-treated MSCs was also upregulated by miR-133a antagomir. Then we investigated the effect of miR-133a silencing on the bone architecture of GIO models, micro-CT analysis showed that miR-133a antagomir attenuated the loss of bone mass and improved the trabecular and cortical parameters induced by methylprednisolone. Histological study showed that miR-133a silencing simultaneously increased bone formation and decreased marrow fat accumulation in GIO rats.

CONCLUSIONS

Our findings suggested that miR-133a is strongly associated with GIO and similar disorders induced by glucocorticoids in MSCs. Silencing miR-133a resulted in positive effects on GC-treated MSCs and on bone loss in GIO animal models. Moreover, the FGFR1-MAPK/ERK signaling may be involved in the protective effect of miR-133a silencing.

KDM5C Expedites Lung Cancer Growth and Metastasis Through Epigenetic Regulation of MicroRNA-133a

Background

KDM5C, a histone H3K4-specific demethylase, possess various biological functions in development of cancers. However, its relation to the microRNA (miRNA) regulation in lung cancer remains unknown. This study aims to study the regulatory role of KDM5C on modification of miR-133a in the progression of lung cancer.

Methods

Differentially expressed miRNAs were filtered from 34 paired lung cancer and paracancerous tissues. The correlation between miR-133a expression and the prognosis of lung cancer patients was determined by a bioinformatics website. Furthermore, malignant aggressiveness of lung cancer cells was detected after miR-133a upregulation by CCK-8, flow cytometry, and Transwell assays and in vivo tumorigenesis and metastasis experiments. Subsequently, we analyzed mRNA downregulated in cells overexpressing miR-133a using m microarray analysis and expounded the upstream regulatory mechanism of miR-133a using bioinformatics website prediction and functional validation.

Results

miR-133a was reduced in lung cancer tissues, and patients with low expression of miR-133a have worse survival rates. miR-133a restoration curtailed growth and metastasis of lung cancer cells in vitro and in vivo. Moreover, miR-133a downregulated PTBP1 expression, whereas overexpression of PTBP1 attenuated the suppressive effect of miR-133a on lung cancer cell aggressiveness. The level of methylation modification of miR-133a was reduced in lung cancer cells. KDM5C inhibited the expression of miR-133a by promoting the demethylation modification of its promoter histone.

Conclusion

Histone demethylase KDM5C inhibits the expression of miR-133a by elevating the demethylation modification of the promoter histone of miR-133a, thereby promoting the expression of PTBP1, which finally accelerates lung cancer cell growth and metastasis.

The Expression and Role of microRNA-133a in Plasma of Patients with Kawasaki Disease

Kawasaki disease (KD)), also known as mucocutaneous lymph node syndrome (MCLS), is an autoimmune and systemic vasculitis syndrome. Its etiology and pathogenesis are still unclear. microRNAs (miRNA), a novel class of small non-coding RNAs, regulate the expression of multiple protein-encoding genes at the post-transcriptional level. We intend to study the change of miRNA-133a in the plasma of patients with KD, explore the role of miRNA-133a on HUVEC and define the pathogenesis of vascular dysfunction in KD. miRNA-133a expression and the mRNA and protein expression of protein phosphatase 2 catalytic subunit alpha (PPP2CA) were assessed by RT-qPCR and Western blot, respectively. The PPP2CA mRNA 3'UTR was predicted to be the potential target of miRNA-133a by using the miRNA databases and verified by the luciferase assay. The plasmids of miRNA-133a mimics and inhibitors were transfected into HUVEC cells. The plasma soluble vascular endothelial cadherin (sVE-cadherin, the excised extracellular part of VE-cadherin) levels were investigated by ELISA. The results suggested that miRNA-133a was increased by 3.8 times in the acute KD group and by 2.7 times in the convalescent KD group compared with the control group (both P = .000). PPP2CA is the target gene of miRNA-133a and its expression was inhibited by miRNA-133a acting on PPP2CA mRNA 3'UTR (P = .013). The plasma sVE-cadherin levels in the acute KD groups were increased compared with the control group (P = .024). The ROC curve analysis showed that the expression of miRNA-133a segregate acute KD patients from convalescent KD patients and healthy children. Our results suggest that miRNA-133a might be a new biomarker for KD.

Circulating microRNA-133a in Patients With Arterial Hypertension, Hypertensive Heart Disease, and Left Ventricular Diastolic Dysfunction

Aim: The aim of the work was to study the circulating microRNA-133a levels in blood plasma of patients with arterial hypertension (AH), hypertensive heart disease (HHD), and left ventricular (LV) diastolic dysfunction (DD). Materials and Methods: A total of 48 patients with grade 2-3 AH and HHD at the age of 52.23 ± 7.26 (23 patients had LV DD [main group] and 25 patients had normal LV diastolic function [comparison group]) and 21 practically healthy individuals of comparable gender and age were examined. Diagnosis of AH and HHD was carried out according to the 2018 ESC/ESH recommendations. LV DD was determined according to the 2016 ASE/EACVI recommendations. Plasma microRNA-133a level was obtained by polymerase chain reaction using the CFX96 Touch System (BioRad), ≪TaqMan microRNA Assay≫ and ≪TaqMan® Universal PCR Master Mix≫ reagent kits (Thermo Fisher Scientific, USA). Results: We have found that in patients from the main and comparison groups plasma microRNA-133a levels were significantly lower than in practically healthy individuals (0.094 [0.067, 0.147]) and (0.182 [0.102, 0.301]) vs. (0.382 [0.198,0.474]), p = 0.002 and p = 0.04, respectively. In all this among patients with AH, HHD, and LV DD, plasma microRNA-133a levels were significantly lower than in patients with AH, HHD, and normal diastolic function (p = 0.03). In the main and comparison groups there was a statistically significant negative relationship between plasma microRNA-133a level and left ventricular mass index (LVMI) (R = -0.40, p = 0.003 and R = -0.35, p = 0.04, respectively). Conclusions: The findings suggest the significant role of decreased microRNA-133a levels in blood plasma of patients with AH in the pathogenesis and development of both HHD and LV DD.

Diagnostic performance for declined microRNA-133a in pancreatic cancer

MicroRNA-133a (MiR-133a) is proven to exhibit a decreasing tendency in several cancers, as well as pancreatic cancer. Through the present study, we inspected performance for serum miR-133a in diagnosing pancreatic cancer. Serum samples were collected from 110 pancreatic cancer and 64 healthy persons. Relative messenger RNA level for miR-133a in serum specimens was gauged adopting quantitative real-time polymerase chain reaction (qRT-PCR), and compared betwixt two groups employing the Student t test. Receiver operating characteristics (ROC) analysis evaluated miR-133a performance in diagnosing pancreatic cancer. MiR-133a displayed a declining trend among pancreatic cancer samples, compared to the healthy controls (P < .001). The reduced miR-133a degree held strong relation to tumor dimension (P = .002), vessel invasion (P = .004), tumor lymph node metastasis stage (P = .002), and lymph node metastasis (P < .001). In addition, ROC analysis demonstrated that the area under the curve value was 0.893, accompanied by a sensitivity of 90.6% and a specificity of 87.2%, revealing fine execution for serum miR-133a in diagnosing cancer. The downregulation of miR-133a might possess a tight relation to hostile advancement in pancreatic cancer. Serum miR-133a could function as a potential diagnostic indicator for pancreatic cancer.

Elevated serum miR-133a predicts patients at risk of periprocedural myocardial injury after elective percutaneous coronary intervention

BACKGROUND

Periprocedural myocardial injury (PMI) is a frequent complication of percutaneous coronary intervention (PCI) associated with poor prognosis. However, no effective method has been found to identify patients at risk of PMI before the procedure. MicroRNA-133a (miR-133a) has been reported as a novel biomarker in various cardiovascular diseases. Herein, it was sought to determine whether circulating miR-133a could predict PMI before the procedure.

METHODS

Eighty patients with negative preoperative values of cardiac troponin T (cTnT) receiving elective PCI for stable coronary artery disease (CAD) were recruited. Venous serum samples were collected on admission and within 16-24 hours post-PCI for miRNA measurements. PMI was defined as a cTnT value above the 99% upper reference limit (URL) after the procedure. The association between miR-133a and PMI was further assessed.

RESULTS

Periprocedural myocardial injury occurred in 48 patients. The circulating level of miR-133a was significantly higher in patients with PMI before and after the procedure (both p < 0.001). Receiver operating characteristic curve analysis of the preoperative miR-133a level revealed an area under the curve (AUC) of 0.891, with a sensitivity of 93.8% and a specificity of 71.9% to predict PMI. Additionally, a decrease was found in fibroblast growth factor receptor 1 (FGFR1) in parallel with an increase in miR-133a levels in patients with PMI.

CONCLUSIONS

This study demonstrates for the first time that serum miR-133a can be used as a novel biomarker for early identification of stable CAD patients at risk of PMI undergoing elective PCI. The miR-133a-FGFR1 axis may be involved in the pathogenesis of PMI.

lncRNA XIST promotes glioma proliferation and metastasis through miR-133a/SOX4

Glioma is the most common malignant brain tumour in adults, and the aetiology and mechanism of this tumour remain largely unknown. Previous studies have demonstrated that the long non-coding RNA X-inactive specific transcript (XIST) is upregulated in many cancers, and a high expression level of XIST is associated with poor clinical outcome. In the present study, the expression and function of XIST were investigated in the glioma cell line U251. XIST and microRNA (miR)-133a levels in glioma cell lines were detected by reverse transcription-quantitative polymerase chain reaction. Small hairpin RNA XIST (sh-XIST) and mimics/inhibitor of miR-133a were transfected in glioma cell lines and cell proliferation, invasion, migration and epithelial-mesenchymal transition (EMT) were examined. Luciferase assays were used to verify the associations among XIST, miR-133a and SRY-box (SOX)4. When XIST was knocked down, the proliferation, metastasis and EMT of glioma cells decreased. Notably, downstream genes of SOX4 were also upregulated or downregulated upon sh-XIST treatment. Overexpression of miR-133a inhibited glioma proliferation, metastasis and EMT via reducing the expression of SOX4; in contrast, knockdown of miR-133a exhibited the opposite effect, which revealed that miR-133a negatively regulates glioma progression. Furthermore, using luciferase assays, it was demonstrated that XIST and SOX4 could bind miR-133a in the predicted binding site; XIST competed with SOX4 for miR-133a binding. In conclusion, a XIST/miR-133a/SOX4 axis and a mechanism of XIST glioma in promoting cell proliferation and metastasis were revealed. These findings revealed that XIST has an oncogenic role in the tumourigenesis of glioma and may serve as a potential therapeutic target for glioma.

Cryptotanshinone inhibits lung cancer invasion via microRNA-133a/matrix metalloproteinase 14 regulation

Cryptotanshinone inhibits the proliferative and colony formation abilities of human non-small cell lung cancer cells (NSCLCs). The present study reported that signal transducer and activator of transcription 3 is not the only target of cryptotanshinone during the inhibition of human NSCLCs. It was identified that cryptotanshinone upregulates the expression levels of microRNA (miR)-30d-5p, miR-126-3p, miR-133a, miR-338-3p and miR-451a, and downregulates miR-21-5p, miR-96-5p, miR-182-5p and miR-205-5p. Among these, miR-133a was the most significantly upregulated. miR-133a targets and downregulates the expression of matrix metalloproteinase (MMP)14; however, MMP15, MMP16 and MMP24 were determined to be unaffected. This process was identified to be independent of tissue inhibitor of metalloproteinases 2. Cryptotanshinone also suppresses the invasion of human NSCLCs, which may be due to the inhibited expression of MMP14. In conclusion, cryptotanshinone may serve as a potential therapeutic agent in the treatment of lung cancer.

Distal-less homeobox 3, a negative regulator of myogenesis, is downregulated by microRNA-133

Distal-less homeobox 3 (Dlx3), a member of the Dlx family of homeobox proteins, is a transcriptional activator of runt-related transcription factor 2 (Runx2) during osteogenic differentiation. It has been demonstrated that forced expression of Runx2 induces an osteogenic program and ectopic calcification in muscles. Therefore, it would be reasonable to predict that Dlx3 also affects myogenic differentiation. The relationship between Dlx3 and myogenesis, however, remains poorly understood. Therefore, in this study, the role and regulation of Dlx3 during myogenic differentiation were investigated. Expression level of Dlx3 was downregulated in human mesenchymal stem cells (MSCs), mouse MSCs, and C2C12 cells cultured in myogenic medium. Dlx3 level was inversely correlated with myogenic differentiation 1 and the muscle-specific microRNA, microRNA-133 (miR-133). The expression level of Runx2 was closely regulated by Dlx3 even under myogenic conditions. Overexpression of Dlx3 markedly downregulated expression levels of myogenic transcription factors and myotube formation in C2C12 cells, whereas Dlx3 knockdown enhanced myogenic differentiation. The Dlx3 3'-untranslated region (3'-UTR) has two potential binding sites for miR-133. Luciferase reporter assays demonstrated that Dlx3 is a direct target of miR-133a and miR-133b, and that the two target sites are redundantly active. Taken together, these results suggest that Dlx3 is a negative regulator of myogenic differentiation and that miR-133a and miR-133b enhance myogenic differentiation, partly through inhibition of Dlx3 expression via direct targeting of the Dlx3 3'-UTR.

MicroRNA-133a downregulated EGFR expression in human non-small cell lung cancer cells via AKT/ERK signaling

MicroRNAs (miRNAs) may serve important roles in the regulation of human non-small cell lung cancer (NSCLC) cell growth and apoptosis. To the best of our knowledge, the present study was the first to explore the role of miRNA-133a/epidermal growth factor receptor (EGFR) in regulating NSCLC cell growth and apoptosis via the AKT/extracellular signal-regulated kinase (ERK) signaling pathway. It was determined that miRNA-133a expression was lower in NSCLC tissue than in the adjacent mucosae. Additionally, EGFR expression in the NSCLC tissue was higher compared with in the adjacent mucosae. Furthermore, the upregulation of miRNA-133a in NSCLC cells suppressed cell growth and induced apoptosis. Upregulating miRNA-133a also increased caspase-3 protein expression, while suppressing that of EGFR, phosphorylated (p)-AKT and p-ERK in NSCLC cells. Therefore, the results of the current study demonstrated that miRNA-133a downregulates EGFR expression in NSCLC via the AKT/ERK signaling pathway. These findings provide insights into the function of miRNA-133a in NSCLC, as well as into the molecular mechanisms underlying the miRNA-133a-mediated downregulation of the EGFR/AKT/ERK signaling pathway in NSCLC.

Reversine promotes browning of white adipocytes by suppressing miR-133a

Brown adipocytes are characterized by a high number of uncoupling protein 1 (UCP1)-positive mitochondrial content and increased thermogenic capacity. As UCP1-enriched cells can consume lipids by generating heat, browning of white adipocytes is now highlighted as a promising approach for the prevention of obesity and obesity-associated metabolic diseases. Upon cold exposure or β-adrenergic stimuli, downregulation of microRNA-133 (miR-133) elevates the expression levels of PR domain containing 16 (Prdm16), which has been shown to be a brown adipose determination factor, in brown adipose tissue and subcutaneous white adipose tissues (WAT). Here, we show that treatment of reversine to white adipocytes induces browning via suppression of miR-133a. Reversine treatment promoted the expression of brown adipocyte marker genes, such as Prdm16 and UCP1, increasing the mitochondrial content, while decreasing the levels of miR-133a and white adipocyte marker genes. Ectopic expression of miR-133a mimic reversed the browning effects of the reversine treatment. Moreover, intraperitoneal administration of reversine in mice upregulated thermogenesis and resulted in resistance to high-fat diet-mediated weight gain as well as browning of subcutaneous and epididymal WAT. Taken together, we found a novel way to promote browning of white adipocytes through downregulation of miR-133a followed by activation of Prdm16, with a synthetic chemical, reversine.

SLC6A1-miR133a-CDX2 loop regulates SK-OV-3 ovarian cancer cell proliferation, migration and invasion

The present study assessed the expression of solute carrier 6 member 1 (SLC6A1) in ovarian cancer (OC) tissues and evaluated the effect of silencing SLC6A1 or caudal type homeobox 2 (CDX2) on the proliferation, migration, and invasion of SK-OV-3 OC cells. The levels of caudal type homeobox 2 (CDX2) and SLC6A1 mRNA were also examined in OC SK-OV-3, OVCAR3 and A2780 cell lines. The mRNA levels of CDX2 and SLC6A1 in SK-OV-3 OC cells were assessed following transection with microRNA (miR) 133a mimics; the mRNA and protein levels of SLC6A1 were determined following the silencing of CDX2, and the mRNA expression of CDX2 was gauged following the silencing of SLC6A1. A luciferase reporter assay was performed to assess the effect of miR133a on the CDX2 and SLC6A1 3′-untranslated regions (3′UTRs). The proliferation, migration and invasion rate of SK-OV-3 cells were then examined following the silencing of CDX2 or SLC6A1. The expression of SLC6A1 was increased in OC compared with adjacent tissue. The expression of CDX2 and SLC6A1 in SK-OV-3 and OVCAR3 cells was increased compared with A2780 cells (P<0.05). The level of CDX2 and SLC6A1 mRNA in SK-OV-3 cells decreased when the cells were transected with the miR133a mimics, compared with a negative control (P<0.05). Transfection with the miR133a mimics significantly reduced the luciferase activity of reporter plasmids with the SLC6A1 or CDX2 3′UTRs (P<0.05). The mRNA level of CDX2 was decreased subsequent to the silencing of SLC6A1; the mRNA and protein level of SLC6A1 were decreased when CDX2 was silenced (P<0.05). The proliferation, migration, and invasion of SK-OV-3 cells were significantly reduced following the silencing of CDX2 or SLC6A1 (P<0.05). CDX2 may therefore be inferred to promote the proliferation, migration and invasion in SK-OV-3 OC cells, acting as a competing endogenous RNA.

RETRACTED: The in vitro and in vivo effects of microRNA-133a on intervertebral disc destruction by targeting MMP9 in spinal tuberculosis

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figure 4 A+C, which appear to have a similar phenotype as seen in many other publications, as detailed here: https://pubpeer.com/publications/0D0667F09124C7911264C51064AF20; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. The journal requested that the corresponding author comment on these concerns and provide the raw data. The authors did not respond to this request and therefore the Editor-in-Chief decided to retract the article.

microRNA-133a attenuates cardiomyocyte hypertrophy by targeting PKCδ and Gq

During the past decade, microRNAs have continuously been suggested as a promising therapeutic tool due to their beneficial effects, such as their multi-targets and multi-functions in pathologic conditions. As a pathologic phenotype is generally regulated by multiple signaling pathways, in this study we identified a microRNA regulating multiple target genes within cardiac hypertrophic signaling pathways. microRNA-133a is known to play a crucial role in cardiac hypertrophy. However, the role of microRNA-133a, which may regulate several signaling pathways in norepinephrine-induced cardiac hypertrophy via multi-targeting, has not been investigated. In the current study, we showed that microRNA-133a can protect cardiomyocyte hypertrophy against norepinephrine stimulation in neonatal rat ventricular cardiomyocytes via new targets, PKCδ and Gq, all of which are related to downstream signaling pathways of the α₁-adrenergic receptor. Taken together, these results suggest the advantages of the therapeutic use of microRNAs as an effective potential drug regulating multiple signaling pathways under pathologic conditions.

Aging-associated changes in microRNA expression profile of internal anal sphincter smooth muscle: Role of microRNA-133a

A comprehensive genomic and proteomic, computational, and physiological approach was employed to examine the (previously unexplored) role of microRNAs (miRNAs) as regulators of internal anal sphincter (IAS) smooth muscle contractile phenotype and basal tone. miRNA profiling, genome-wide expression, validation, and network analyses were employed to assess changes in mRNA and miRNA expression in IAS smooth muscles from young vs. aging rats. Multiple miRNAs, including rno-miR-1, rno-miR-340-5p, rno-miR-185, rno-miR-199a-3p, rno-miR-200c, rno-miR-200b, rno-miR-31, rno-miR-133a, and rno-miR-206, were found to be upregulated in aging IAS. qPCR confirmed the upregulated expression of these miRNAs and downregulation of multiple, predicted targets (Eln, Col3a1, Col1a1, Zeb2, Myocd, Srf, Smad1, Smad2, Rhoa/Rock2, Fn1, Tagln v2, Klf4, and Acta2) involved in regulation of smooth muscle contractility. Subsequent studies demonstrated an aging-associated increase in the expression of miR-133a, corresponding decreases in RhoA, ROCK2, MYOCD, SRF, and SM22α protein expression, RhoA-signaling, and a decrease in basal and agonist [U-46619 (thromboxane A₂ analog)]-induced increase in the IAS tone. Moreover, in vitro transfection of miR-133a caused a dose-dependent increase of IAS tone in strips, which was reversed by anti-miR-133a. Last, in vivo perianal injection of anti-miR-133a reversed the loss of IAS tone associated with age. This work establishes the important regulatory effect of miRNA-133a on basal and agonist-stimulated IAS tone. Moreover, reversal of age-associated loss of tone via anti-miR delivery strongly implicates miR dysregulation as a causal factor in the aging-associated decrease in IAS tone and suggests that miR-133a is a feasible therapeutic target in aging-associated rectoanal incontinence.

Prognostic value of decreased microRNA-133a in solid cancers: a meta-analysis

OBJECTIVE

Increasing evidence indicates that the decreased expression of microRNA-133a (miR-133a) may be correlated with poor survival for cancer patients. Thus, we performed this meta-analysis to evaluate the prognostic value of decreased miR-133a in solid cancers.

METHODS

Eligible studies were gathered by searching on PubMed, Web of Science, and Embase. Using the STATA 12.0 software, the pooled hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) for total and subgroup analyses were calculated to investigate the possible correlation between decreased miR-133a and overall survival (OS) of patients with cancer.

RESULTS

Ten studies were enrolled in this meta-analysis. The pooled result showed that decreased expression of miR-133a predicted poor OS in solid cancer patients (HR =1.62, 95% CI: 1.16-2.24, P=0.004). Compared with the total pooled HR, further analyses indicated that the subgroups of digestive system neoplasms (HR =1.73, 95% CI: 1.20-2.51, P=0.003), frozen tissue preservation (HR =1.89, 95% CI: 1.41-2.53, P<0.001), and multivariate analysis (HR =2.07, 95% CI: 1.42-3.02, P<0.001) exhibited stronger connection between decreased miR-133a expression and OS outcome.

CONCLUSION

This meta-analysis suggested that decreased miR-133a was associated with poor OS in patients with solid cancer. Because of the data in our study are limited, additional studies are required to verify the poor prognosis of decreased miR-133a in solid tumors.

MicroRNA-133a suppresses colorectal cancer cell invasion by targeting Fascin1

MicroRNAs (miRs) are a type of small non-coding RNA molecule that are involved in gene silencing and the regulation of cancer progression; miR-133a in particular has been implicated in colorectal cancer, although its specific role and underlying mechanism have yet to be determined. In the present study, the expression level of miR-133a was significantly downregulated in a number of colorectal cancer cell lines, as well as in colorectal cancer tissues compared with the normal adjacent tissues. Furthermore, the Fascin1 (FSCN1) gene was identified as a direct target of miR-133a, and the protein expression level of FSCN1 was negatively regulated by miR-133a in colorectal cancer cells. Additionally, restoration of miR-133a expression and downregulation of FSCN1 protein expression suppressed colorectal cancer cell invasion, while overexpression of FSCN1 reversed the inhibitory effect of miR-133a upregulation on colorectal cancer cell invasion. Thus, the present data indicates that miR-133a may at least partially suppress colorectal cancer cell invasion, possibly via the inhibition of FSCN1 expression. The present study highlights the important role of miR-133a in the progression of colorectal cancer.

Role of microRNA-133a in epithelial ovarian cancer pathogenesis and progression

It has been demonstrated that microRNA (miR)-133a is downregulated in a number of human malignancies and is closely associated with the progression of tumors. The present study was conducted to investigate the contribution of miR-133a to the initiation and malignant progression of human epithelial ovarian cancer (EOC). Quantitative polymerase chain reaction was employed to detect the expression of miR-133a in the human EOC OVCAR-3 cell line, normal human ovarian surface epithelial (tsT) cells and 96 tissue samples, including 70 EOC tissues and 26 normal ovarian tissue sections. Additionally, analysis of the correlation between miR-133a levels and clinicopathological characteristics was carried out. The effect of miR-133a on cell viability, apoptosis, invasion and migration was investigated following transfection with miR-133a mimics and negative control small interfering RNA in OVCAR-3 cells. Marked downregulation of miR-133a was observed in the OVCAR-3 cell line and primary tumor samples, and it was found that reduced miR-133a expression significantly correlated with advanced clinical stages, poor histological differentiation and lymph node metastasis. Furthermore, OVCAR-3 cell viability, invasion and migration were significantly inhibited, while cell apoptosis was increased, following transfection of miR-133a mimics. The present study reveals the critical role that miR-133a plays in EOC pathogenesis and development, indicating that it may act as a promising biomarker for predicting EOC progression and as a potential target for gene therapy.