miRNA genetic variants: As potential diagnostic biomarkers for oral cancer

MicroRNAs (miRNAs) comprise a novel class of small, non-coding endogenous RNAs that have a role in the plethora of regulatory activities by directing their target mRNAs for degradation or translational repression. Single nucleotide polymorphisms (SNPs) in miRNA genes can lead to alteration in mRNA expression, resulting in serious consequences. Detection of miRNA-polymorphisms can potentially improve diagnosis, treatment, prognosis in patients and has extreme implications in the fields of pharmacogenomics and personalization of medicine. The aim of this study is to investigate the association between miR-499 A/G and miR-149 C/T polymorphisms with susceptibility to development of Oral Squamous Cell Carcinoma (OSCC). 200 histopathologically diagnosed and confirmed samples from OSCC patients and 200 control samples from the general population were recruited for the study. All OSCC patients were graded based on their differentiation, and genetic analysis was performed by PCR-RFLP and sequencing. qRT-PCR was carried out to compare the expression of miR-499 and miR-149 in different grades of various stages of OSCC patients concerning to the controls. Further Immunohistochemistry (IHC) was performed to study the target gene of miR-499. The study shows a probable association of miR-499 A/G and miR-149 C/T with susceptibility of OSCC. Random sequencing analysis and Immunohistochemistry contribute to the result that miR-499 A/G increases the susceptibility of OSCC by targeting SOX-6. PCR- Restriction Fragment Length Polymorphism (RFLP) and multivariable logistic analysis revealed that there is a significant association between miR-149 CT+TT and CT and susceptibility of OSCC. Our study suggests that miR-499 A/G and miR-149 C/T polymorphisms may play crucial roles in susceptibility and development of OSCC in Indian population.

miR-149 promotes human osteocarcinoma progression via targeting bone morphogenetic protein 9 (BMP9)

OBJECTIVES

To investigate the roles of miR-149 in the progression of human osteosarcoma (OS).

RESULTS

miR-149 level was upregulated in tissues from OS patients more than in normal subjects. Cell proliferation and apoptosis assays revealed that miR-149 increased cell proliferation and inhibited cell apoptosis in OS cell line (MG63). An increase of Bcl-2 gene expression and a decrease of cleaved-caspase-3, and cleaved-PARP expression were observed in MG63 cells with transfection of miR-149. Additionally, bone morphogenetic protein 9 (BMP9) was identified as a target of miR-149 in MG63 cells, and BMP9 expression was negatively correlated with miR149 level in OS clinical samples. Co-overexpression of BMP9 with miR-149 in MG63 cells prohibited miR-149-mediated promotive effects on OS progression. Importantly, overexpression of miR-149 conferred chemoresistance in MG63 cells.

CONCLUSIONS

miR-149 promotes OS progression via targeting BMP9.

Anti-inflammatory effects of millet bran derived-bound polyphenols in LPS-induced HT-29 cell via ROS/miR-149/Akt/NF-κB signaling pathway

The pro-inflammatory and anti-inflammatory maladjustment has been acknowledged as one of the chief causations of inflammatory diseases and even cancers. Previous studies showed that plant-derived polyphenolic compounds were the most potent anti-oxidant and anti-inflammatory agents among all natural compounds. The present study indicates that bound polyphenols of inner shell (BPIS) from foxtail millet bran can display anti-inflammatory effects in LPS-induced HT-29 cells and in nude mice. Mechanistically, BPIS restrained the level of various pro-inflammatory cytokines (IL-1β, IL-6, IL-8), and enhanced the expression level of anti-inflammatory cytokine (IL-10) by blocking the nuclear factor-kappaB (NF-κB)-p65 nuclear translocation. Further, we found the elevated miR-149 expression by BPIS-induced ROS accumulation, directly targeted the Akt expression to block NF-κB nuclear translocation. Taken together, these novel findings provide new insights into the development of BPIS as an anti-inflammatory agent via the signaling cascade of ROS/miR-149/Akt/NF-κB axis.

Association of MiR-149 (RS2292832) Variant with the Risk of Coronary Artery Disease

Background

Coronary artery disease (CAD) is the most common cause of mortality and disability from incommunicable disease in the world. Although the association between the single nucleotide polymorphisms (SNPs) in protein-coding genes and the risk of CAD has been investigated extensively, very few heart-disease associated studies concerning the SNPs in miRNA genes have been reported. The present study was performed to elucidate the association between the pre-microRNA-149 (miR-149) SNP rs2292832 and the risk of CAD in an Iranian population.

Methods

Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were performed to identify the genotypes of the miR-149 SNP rs2292832 in 421 unrelated subjects (272 with CAD and 149 controls).

Results

Our analysis revealed that the TT genotype was more frequent in CAD patients than control subjects (P=0.02) implying that TT genotype should be considered as a risk factor in CAD development (TT vs. TC+CC p=0.02, OR=1.88).

Conclusions

The present study suggests that rs2292832-TT in pre-miR-149 is associated with CAD in an Iranian population.

Effect of SMYD3 on the microRNA expression profile of MCF-7 breast cancer cells

SET and MYND domain containing 3 (SMYD3) is a histone methyltransferase (HMT) and transcription factor, which serves important roles in carcinogenesis. Numerous downstream target genes of SMYD3 have been identified in previous studies. However, the downstream microRNA (miRNA) s regulated by SMYD3 are yet to be elucidated. In the present study, the results of miRNA microarray demonstrated that 30 miRNA expression profiles were upregulated, whilst 24 miRNAs were downregulated by >2.0-fold in the SMYD3-overexpressed MCF-7 breast cancer cells. The HMT activity was demonstrated to be essential for SMYD3-mediated transactivation of miR-200c-3p and the overexpression of miR-200c-3p inhibited the transactivation effects of SMYD3 on myocardin-related transcription factor-A-dependent migration-associated genes. To our best knowledge, the current study is the first to report on the transcriptional regulation of SMYD3 on miRNAs, and miR-200c may be a downstream negative regulator of the SMYD3-mediated pathway in the migration of breast cancer cells. These results may provide a novel theoretical basis to understand the mechanisms underlying the initiation, progression, diagnosis, prevention and therapy of breast cancer.

EphB3-targeted regulation of miR-149 in the migration and invasion of human colonic carcinoma HCT116 and SW620 cells

microRNAs play key roles during various crucial cell processes such as proliferation, migration, invasion and apoptosis. Also, microRNAs have been shown to possess oncogenic and tumor‐suppressive functions in human cancers. Here, we describe the regulation and function of miR‐149 in colorectal cancer cell lines. miR‐149 expression patterns were detected in human colorectal cell lines and tissue samples, and then focused on its role in regulation of cell growth, migration, invasion, and its target gene identification. Furthermore, the function of the target gene of miR‐149 was analyzed in vitro and in vivo. miR‐149 expression was downregulated in human colorectal cancer HCT116 and SW620 cell lines compared to the normal colon epithelial NCM460 cell line using quantitative real‐time polymerase chain reaction methods. Further studies indicated that introduction of miR‐149 was able to suppress cell migration and invasion. Then, EphB3 was identified as a direct target gene of miR‐149 in colorectal cancer cells. Moreover, experiments in vitro showed that knockdown expression of EphB3 could suppress cell proliferation and invasion, and ectopic expression of EphB3 restored the phenotypes of CRC cell lines transfected with miR149. In addition, silencing of EphB3 significantly affected cycle progression distribution and increased apoptosis in CRC cell lines. Finally, in vivo results demonstrated that knockdown of EphB3 by siRNA inhibited tumor growth. In conclusion,the important role of miR‐149 in colorectal cancer progression suggesting that miR‐149 may serve as a therapeutic target for colorectal cancer treatment.

MicroRNA-149 is associated with clinical outcome in human neuroblastoma and modulates cancer cell proliferation through Rap1 independent of MYCN amplification

PURPOSE

We evaluated the clinical relevance of microRNA-149 (miR-149) in neuroblastoma (NB) and its functional roles in regulating NB proliferation in vitro.

METHODS

QRT-PCR was used to evaluate miR-149 expression in NB cell lines and primary NB tumors. Association between endogenous miR-149 expression in primary NB tumors and their host patients' clinicopathological factors and overall survival (OS) were statistically evaluated. In SH-SY5Y, an MYCN-non-amplified, and LAN5, an MYCN-amplified NB cell lines, miR-149 was either upregulated or downregulated by lentiviral transduction, to evaluate its effect on NB proliferation in vitro. Possible downstream target of miR-149, Ras-related protein 1 (Rap1), was evaluated by qRT-PCR and western blot in lentiviral-transduced NB cells. Moreover, Rap1 was either upregulated or downregulated in lentiviral-transduced NB cells to further evaluate its effect on miR-149-mediated NB proliferation in vitro.

RESULTS

MiR-149 is markedly downregulated in both in vitro NB cell lines and in vivo NB primary tumors. Low miR-149 expression is predominantly associated with Stage 3 or 4 primary NB tumors, and poor OS among NB patients. In SH-SY5Y and LAN5 cells, lentivirus-induced miR-149 upregulation inhibited, whereas miR-149 downregulation promoted NB proliferation in vitro, despite MYCN-amplification status. Rap1 expression, at both mRNA and protein levels, was inversely associated with miR-149 in NB. In addition, Rap1 upregulation or downregulation reversely regulated miR-149-mediated NB proliferation in vitro.

CONCLUSION

MiR-149 is downregulated in NB and closely associated with NB patients' clinical outcome. MiR-149 also functionally modulates NB cell proliferation in vitro, possibly through inverse-regulation on Rap1.

miR-149 represses metastasis of hepatocellular carcinoma by targeting actin-regulatory proteins PPM1F

microRNAs have been implicated in hepatocellular carcinoma (HCC) metastasis, which is predominant cause of high mortality in these patients. Although an increasing body of evidence indicates that miR-149 plays an important role in the growth and metastasis of multiple types of cancers, its role in the progression of HCC remains unknown. Here, we demonstrated that miR-149 was significantly down-regulated in HCC, which was correlated with distant metastasis and TNM stage with statistical significance. A survival analysis showed that decreased miR-149 expression was correlated with a poor prognosis of HCC as well. We found that over-expression of miR-149 suppressed migration and invasion of HCC cells in vitro. In addition, we identified PPM1F (protein phosphatase, Mg(2+)/Mn(2+)-dependent, 1F) as a direct target of miR-149 whose expression was negatively correlated with the expression of miR-149 in HCC tissues. The re-expression of PPM1F rescued the miR-149-mediated inhibition of cell migration and invasion. miR-149 regulated formation of stress fibers to inhibit migration, and re-expression of PPM1F reverted the miR-149-mediated loss of stress fibers. Moreover, we demonstrated that over-expression of miR-149 reduced pMLC2, a downstream effector of PPM1F, in MHCC-97H cells. In vivo studies confirm inhibition of HCC metastasis by miR-149. Taken together, our findings indicates that miR-149 is a potential prognostic biomarker of HCC and that the miR-149/PPM1F regulatory axis represents a novel therapeutic target for HCC treatment.

The clinicopathological significance of miR-149 and PARP-2 in hepatocellular carcinoma and their roles in chemo/radiotherapy

Hepatocellular carcinomas (HCC) are commonly diagnosed at an advanced stage with unresectable tumors. Although numerous non-surgical approaches have been developed to treat HCC, the prognosis of patients with HCC is still poor. This study investigated the expression of miR-149 and PARP-2 in HCC tumor tissues and their roles in sensitizing chemo/radiotherapy. The expression of miR-149 was measured by real-time PCR, and PARP-2 protein was measured by immunohistochemistry and Western blot. The xenograft HCC mouse model was established by inoculating Hep G2 cells. Increased PARP-1 and decreased miR-149 expression was observed in HCC tissues compared to peritumoral tissues. Positive PARP-2 and low miR-149 expression correlated with larger tumor mass size (P < 0.001), capsular and vascular invasion (P < 0.001), lymph node metastasis (P = 0.02), high histological grade (P < 0.001), TNM (P < 0.001), and BCLC grade (P = 0.001). The Kaplan-Meier survival analysis showed a negative correlation between high PARP-2 expression or low miR-149 expression in HCC tissues with the survival of patients. High PARP-2 and low miR-149 correlated with a low 5-year survival rate and are poor prognosis factors. Overexpression of miR-149 or inhibition of PARP-2 expression could inhibit tumor growth but was more effective in sensitizing chemotherapy and radiotherapy in xenograft HCC animal models. Increased PARP-2 expression and loss of miR-149 expression are involved in the pathogenesis of HCC and are poor prognosis factors in patients with HCC. Although both miR-149 overexpression and PARP-2 inhibitor exert some antitumoral effect, PARP-2 inhibitor is a chemo/radio sensor and can be used to enhance chemotherapy and radiotherapy in patients with HCC.

miR-149 controls non-alcoholic fatty liver by targeting FGF-21

Non‐alcoholic fatty liver disease (NAFLD), a lipid metabolism disorder characterized by the accumulation of intrahepatic fat, has emerged as a global public health problem. However, its underlying molecular mechanism remains unclear. We previously have found that miR‐149 was elevated in NAFLD induced by high‐fat diet mice model, whereas decreased by a 16‐week running programme. Here, we reported that miR‐149 was increased in HepG2 cells treated with long‐chain fatty acid (FFA). In addition, miR‐149 was able to promote lipogenesis in HepG2 cells in the absence of FFA treatment. Moreover, inhibition of miR‐149 was capable of inhibiting lipogenesis in HepG2 cells in the presence of FFA treatment. Meanwhile, fibroblast growth factor‐21 (FGF‐21) was identified as a target gene of miR‐149, which was demonstrated by the fact that miR‐149 could negatively regulate the protein expression level of FGF‐21, and FGF‐21 was also responsible for the effect of miR‐149 inhibitor in decreasing lipogenesis in HepG2 cells in the presence of FFA treatment. These data implicate that miR‐149 might be a novel therapeutic target for NAFLD.

Association between single nucleotide polymorphism in miR-499, miR-196a2, miR-146a and miR-149 and prostate cancer risk in a sample of Iranian population

MicroRNAs (miRNAs) play an important role in regulating gene expression at the post-transcriptional level and are involved in numerous physiological processes. Accumulating evidence suggests that single-nucleotide polymorphisms (SNPs) in human miRNA genes may affect miRNA biogenesis pathway and influence the susceptibility to several diseases such as cancer. The present study aimed to evaluate the impact of miR-499 rs3746444, miR-196a2 rs11614913, miR-149 rs2292832, and miR-146a rs2910164 polymorphisms on prostate cancer (PCa) risk in a sample of Iranian population. This case-control study was done on 169 patients with pathologically confirmed PCa and 182 benign prostatic hyperplasia (BPH). The genotyping assays were done using T-ARMS-PCR or PCR-RFLP methods. The findings indicated that CC genotype of miR-499 rs3746444 polymorphism increased the risk of PCa (OR = 1.76, 95% CI = 1.12-2.79, P = 0.019) compared to TT genotype. No statistically significant association was found between miR-196a2 rs11614913, miR-149 rs2292832, and miR-146a rs2910164 polymorphisms and PCa risk. In summary, the findings indicated that miR-499 rs3746444 polymorphism increased the risk of PCa in an Iranian population. Further studies with larger sample sizes and different ethnicities are necessary to verify the findings of the present study.

A Meta-Analysis of the Association between Polymorphisms in MicroRNAs and Risk of Ischemic Stroke

Ischemic stroke (IS) is responsible for a high death rate and for adult disability worldwide. MiR-146a (rs2910164), miR-149 (rs2292832), miR-196a2 (rs11614913) and miR-499 (rs3746444) are found to be associated with ischemic stroke. However, the results were inconsistent and inconclusive. The present study performed a meta-analysis to get a more precise and comprehensive estimation of the association between the four polymorphisms and IS risk. The databases Pubmed, Embase, Cochrane Central Register of Controlled Trials, Chinese National Knowledge Infrastructure, and Chinese Biomedical Literature Database were searched for related studies. A total of five studies including 2230 cases and 2229 controls were identified for the meta-analysis. The results indicate that TT genotype and T allele of miR-149 (rs2292832) are associated with significantly lower risks of IS in a homozygous model (OR = 0.70) and an allelic model (OR = 0.86). No significant associations were found between miR-146a (rs2910164), miR-196a2 (rs11614913), miR-499 (3746444) and IS susceptibility in any of the studies. However, subgroup analysis by sample size indicates a significant decrease in risks of IS for CC genotype and C allele of miR-146a (rs2910164) in the large sample size group. Therefore, miR-149 (rs2292832) might be recommended as a predictor for IS risk, while miR-146a (rs2910164), miR-196a2 (rs11614913), miR-499 (3746444) are not.

The miR-149 rs2292832 T/C polymorphism may decrease digestive cancer susceptibility: an updated meta-analysis

MicroRNAs (miRNAs) are a class of short non-coding, single stranded RNAs, which perform post-transcriptional regulatory functions as tumor suppressors or oncogenes. Single nucleotide polymorphisms (SNPs) in miRs genes are currently being identified for contributing to cancer risk, prognosis and survival, however, an association between miR-149 rs2292832 T/C SNP and cancer risk is uncertain. Therefore, we performed an updated meta-analysis of all currently publications to clarify this relationship. From PubMed and Chinese language (WanFang) databases, we located articles published up to June 1, 2015, obtaining 21 case-control studies from 20 different articles containing 8913 cases and 9944 controls based on search criteria for cancer susceptibility related to the miR-149 rs2292832 T/C SNP. Odds ratios (OR) and 95% confidence intervals (CI) revealed association strengths. There had no association between this SNP and whole cancer risk. At the same time, in several subgroups, also no association was found in ethnicity, sex and smoking status. Nevertheless, poorly significant association was detected in cancer type (Digestive cancer: OR = 0.90, 95% CI = 0.81-1.00, Pheterogeneity = 0.142 for CT vs. TT) and source of control (population-based: OR = 1.15, 95% CI = 1.00-1.32, Pheterogeneity = 0.427 for CC vs. CT+TT) subgroups. The miR-149 rs2292832 T/C SNP may poorly decrease digestive cancer risk. Studies with larger samples and gene-environment interactions are warranted to understand the role of miR-149 polymorphisms, especially rs2292832 T/C SNP, in whole cancer risk.

Low MiR-149 expression is associated with unfavorable prognosis and enhanced Akt/mTOR signaling in glioma

MicroRNAs (miRs) play critical roles in the progression of glioma. Previous in vitro studies have described the anti-tumor role of miR-149 in cancer cells including glioma. In this study, we aimed to investigate whether miR-149 is associated with the prognosis of glioma patients. A total of 163 glioma patients who underwent tumor resection were included in our follow-up study. We found that the miR-149 expression was significantly lower in tumor tissues compared with that in normal tissues (P<0.05). Kaplan-Meier and analysis showed that the miR-149 expression status was significantly associated with the survival duration (logrank test, P<0.001), and multivariate Cox regression revealed that patients with low miR-149 expression were exposed to a 1.825 fold higher death risk (HR=1.825, 95% CI=1.031-3.229, P=0.039) compared with those with high miR-149 expression. Further study showed that Akt/mTOR signaling was hyperactive in low miR-149 expressing tissues. Our study thus demonstrates that miR-149 expression in glioma tissues is critically associated with the prognosis of patients, suggesting its potential clinical significance.

Pre-miR-149 rs71428439 polymorphism is associated with increased cancer risk and AKT1/cyclinD1 signaling in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common lethal malignancies in the world, and the current knowledge on the molecular and genetic basis of HCC is still limited. Previous study has shown miR-149 plays a tumor suppressive role in HCC, here we aimed to investigate the association between rs71428439 polymorphism, which located in the pre-miR-149, and the risk of HCC in a Chinese Han population. A total of 177 HCC patients and 103 healthy controls were genotyped, by a multivariate logistic regression, we found that individuals with GG genotype have significantly higher risk of HCC (adjusted OR=3.397, 95% CI=1.565-7.375, P=0.002) compared with those with AA genotype, similar results were also observed in recessive model (adjusted OR=2.563, 95% CI=1.300-5.054, P=0.007) and dominant model (adjusted OR=2.074, 95% CI=1.147-3.752, P=0.016). We further observed that tumor tissues in patients with GG genotype expressed lower level of miR-149 compared with those with AA or AG genotype, and consequently, AKT1, a pre-validated miR-149 target in vitro, was found to have higher expression level in tumors with GG genotype. In summary, our data indicated that rs71428439 may be a genetic risk factor of HCC in the Chinese Han population, and its mechanism possibly involves downregulated miR-149 expression and upregulated AKT1 expression.

Methylation-regulated miR-149 modulates chemoresistance by targeting GlcNAc N-deacetylase/N-sulfotransferase-1 in human breast cancer

Dysregulation of microRNA is strongly implicated in the chemoresistance of cancer. In this study, we found that miR-149 was downregulated and involved in chemoresistance in adriamycin (ADM)-resistant human breast cancer cells (MCF-7/ADM). Downregulation of miR-149 was related to hypermethylation of its 5'-UTR; this methylation also affected the expression of the glypican 1 gene, which is both the host and the target gene of miR-149. Furthermore, we found that miR-149 modulated chemoresistance through targeting the expression of GlcNAc N-deacetylase/N-sulfotransferase-1 (NDST1). With downregulated miR-149, NDST1 expression was increased in chemoresistant MCF-7/ADM cells versus control MCF-7 wild-type cells. The increased NDST1 then activated a heparan sulfate-related pathway involving activation of heparanase. Finally, expression of miR-149 and NDST1 was confirmed in clinical chemoresistant samples of breast cancers receiving anthracycline/taxane-based chemotherapies. The high expression of NDST1 was also an unfavorable predictor for distant relapse-free survival in Her2 and basal breast cancers. Taken together, our findings demonstrate that miR-149 is regulated by methylation, and is a modulator of cancer chemoresistance by targeting NDST1.

Autoregulation of glypican-1 by intronic microRNA-149 fine tunes the angiogenic response to FGF2 in human endothelial cells

MicroRNA-149 (miR-149) is located within the first intron of the glypican-1 (GPC1) gene. GPC1 is a low affinity receptor for fibroblast growth factor (FGF2) that enhances FGF2 binding to its receptor (FGFR1), subsequently promoting FGF2-FGFR1 activation and signaling. Using bioinformatic approaches, both GPC1 and FGFR1 were identified and subsequently validated as targets for miR-149 (both the mature strand, miR-149, and the passenger strand, miR-149*) in endothelial cells (ECs). As a consequence of their targeting activity towards GPC1 and FGFR1, both miR-149 and miR-149* regulated FGF2 signaling and FGF2-induced responses in ECs, namely proliferation, migration and cord formation. Moreover, lentiviral overexpression of miR-149 reduced in vivo tumor-induced neovascularization. Importantly, FGF2 transcriptionally stimulated the expression of miR-149 independently of its host gene, therefore assuring the steady state of FGF2-induced responses through the regulation of the GPC1-FGFR1 binary complex in ECs.

Association study between miR-149 gene polymorphism and nasopharyngeal carcinoma

Association studies between single-nucleotide polymorphism (SNP) rs2292832 on miR-149 gene and cancer risk have been previously analyzed in several types of cancer. The aim of this study was to evaluate the association between miR-149 polymorphism and risk of nasopharyngeal carcinoma (NPC). miR-149 gene polymorphism was genotyped using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) in 158 patients with NPC and 242 healthy individuals. Associations with cancer risk and clinicopathological characteristics were analyzed by χ² test. No significant difference was observed for miR-149 gene polymorphism in NPC patients and healthy controls in either genotype (P=0.427 for CC vs. CT vs. TT, P=0.247 for CT vs. TT and P=0.323 for CC vs. TT, respectively) or allelic analysis (P=0.216). No significant difference was noted between the genotypes and the clinicopathological parameters examined with the exception of clinical stage. A significantly higher CC distribution in clinical stage I-II compared with III-IV was observed under the dominant model (CC vs. CT vs. TT, P=0.026) and the co-dominant model (CC vs. TT, P=0.030). The results of this study suggested that the CC genotype of miR-149 contributes to the progression and development, rather than the initiation of NPC.