Pri-miR-124 rs531564 polymorphism and colorectal cancer risk

miRNA genetic variations associated with the predisposition of oral squamous cell carcinoma in central Indian population

The disease burden of Oral Squamous Cell Carcinoma (OSCC) is rising day-by-day and is expected to rise 62 % through 2035. The chewing of tobacco, areca nut, and betel leaf, poor oral hygiene, and chronic infection are common risk factors of OSCC, but genetic and epigenetic factors also contribute equally. MicroRNAs (miRNAs) are comprised of small, non-coding endogenous RNA that regulate a plethora of biological activities by targeting messenger RNA through degradation or inhibition. Single Nucleotide Polymorphisms (SNPs) in miRNA genes can regulate the development and progression of OSCC. The present study aimed to determine the association between SNPs in miRNA genes (miRSNPs) with the risk of OSCC. A case-control study involving 225 histo-pathologically confirmed OSCC cases and 225 healthy controls was conducted, where 25 miRSNPs were analyzed by iPLEX MassArray analysis. A SNP rs12220909 in MIR4293 showed a highly protective effect (CC vs GG, OR = 0.0431, 95%CI = 0.005-0.323, p = 3e-6). Whereas three SNPs, namely, rs4705342 in MIR143 (CC vs TT, OR = 2.25, 95%CI = 2.00-2.53, p = 0.0008), rs531564 in MIR124 (CC vs GG, OR = 24.18, 95%CI = 3.22-181.37, p = 3e-6), and rs3746444 in MIR499 (AA vs GG, OR = 2.01, 95%CI = 1.32-3.05, p = 0.001) were significantly associated with a higher risk of OSCC. Additionally, NanoString-based nCounter miRNA expression profiling revealed that miR-499a (Log2FC = -1.07), and miR-143 (Log2FC = -1.56) were aberrantly expressed in OSCC tissue. Taken together, the above miSNPs may contribute to the high incidence of OSCC in central India. However, further studies with large cohorts and ethnic stratification are required to validate our findings.

Single Nucleotide Polymorphisms in microRNA Genes and Colorectal Cancer Risk and Prognosis

There is growing interest in single nucleotide polymorphisms (SNPs) in the genes of microRNAs (miRNAs), which could be associated with susceptibility to colorectal cancer (CRC) and therefore for prognosis of the disease and/or treatment response. Moreover, these miRNAs-SNPs could serve as new, low-invasive biomarkers for early detection of CRC. In the present article, we performed a thorough review of different SNPs, which were investigated for a correlation with the CRC risk, prognosis, and treatment response. We also analyzed the results from different meta-analyses and the possible reasons for reported contradictory findings, especially when different research groups investigated the same SNP in a gene for a particular miRNA. This illustrates the need for more case-control studies involving participants with different ethnic backgrounds. According to our review, three miRNAs-SNPs-miR-146a rs2910164, miR-27a rs895819 and miR-608 rs4919510-appear as promising prognostic, diagnostic and predictive biomarkers for CRC, respectively.

ZO-2 favors Hippo signaling, and its re-expression in the steatotic liver by AMPK restores junctional sealing

ZO-2 is a peripheral tight junction (TJ) protein whose silencing in renal epithelia induces cell hypertrophy. Here, we found that in ZO-2 KD MDCK cells, in compensatory renal hypertrophy triggered in rats by a unilateral nephrectomy and in liver steatosis of obese Zucker (OZ) rats, ZO-2 silencing is accompanied by the diminished activity of LATS, a kinase of the Hippo pathway, and the nuclear concentration of YAP, the final effector of this signaling route. ZO-2 appears to function as a scaffold for the Hippo pathway as it associates to LATS1. ZO-2 silencing in hypertrophic tissue is due to a diminished abundance of ZO-2 mRNA, and the Sp1 transcription factor is critical for ZO-2 transcription in renal cells. Treatment of OZ rats with metformin, an activator of AMPK that blocks JNK activity, augments ZO-2 and claudin-1 expression in the liver, reduces the paracellular permeability of hepatocytes, and serum bile acid content. Our results suggest that ZO-2 silencing is a common feature of hypertrophy, and that ZO-2 is a positive regulator of the Hippo pathway that regulates cell size. Moreover, our observations highlight the importance of AMPK, JNK, and ZO-2 as therapeutic targets for blood-bile barrier dysfunction.

MicroRNAs as important contributors in the pathogenesis of colorectal cancer

Colorectal cancer (CRC) is the third most fatal and fourth most frequently diagnosed neoplasm in the world. Numerous non-coding RNAs have been shown to contribute in the development of CRC. MicroRNAs (miRNAs) are among the mostly assessed non-coding RNAs in CRC. These transcripts influence expression and activity of TGF-β, Wnt/β-catenin, MAPK, PI3K/AKT and other CRC-related pathways. In the context of CRC, miRNAs interact with long non-coding RNAs to influence CRC course. Stool and serum levels of miRNAs have been used to distinguish CRC patients from healthy controls, indicating diagnostic roles of these transcripts in CRC. Therapeutic application of miRNAs in CRC has been assessed in animal models, yet has not been verified in clinical settings. In the current review, we have provided a recent update on the role of miRNAs in CRC development as well as diagnostic and prognostic approaches.

Role of MicroRNA-124 as a Prognostic Factor in Multiple Neoplasms: A Meta-Analysis

Objective

MicroRNA-124 (miR-124) was revealed to be an attractive prognostic tumour biomarker in recent studies. However, the results remain inconclusive. Hence, this meta-analysis was carried out to clarify the precise predictive value of miR-124.

Materials and Methods

Relevant studies were searched in PubMed, EMBASE, Web of Science, and the Cochrane Library up to October 2018. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were extracted from the selected studies.

Results

A total of 29 articles investigating the correlation between miR-124 expression and prognosis were initially identified. The pooled HR for overall survival (OS) of high miR-124 expression in multiple cancers was 0.55 (95%CI = 0.50–0.61). Disease-free survival (DFS)/progression-free survival (HR = 0.48, 95%CI = 0.38–0.61) revealed a protective role of increased miR-124 expression. Epigenetic hypermethylation of miR-124 mediated the silencing of its expression, which is correlated significantly with unfavourable survival (OS: HR = 2.06, 95%CI = 1.68–2.53; DFS/recurrence-free survival: HR = 2.77, 95%CI = 1.85–4.16).

Conclusions

Taken together, our results suggest that miR-124 plays an antioncogenic role in various tumors, such as lung cancer and colorectal cancer. If methylation of miR-124 could be prevented, progression and metastasis would be improved; thus, miR-124 may be a promising biomarker and novel therapeutic target. Further large-scale studies are needed to confirm this possible effect.

Correlation between pri-miR-124 (rs531564) polymorphism and congenital heart disease susceptibility in Chinese population at two different altitudes: a case-control and in silico study

The development of congenital heart disease (CHD) is a complicated process and affected by multiple environmental factors, as genetic factors, and the interactions among those factors. Previous studies have shown that intrauterine hypoxic environment exposure is a risk factor of CHD, but the genetic factors involved in the process are not clear. In this study, given that tetralogy of Fallot (TOF) is a CHD with hypoxemia as its primary pathophysiological manifestation, an in silico analysis was performed to reveal the relationship between potential target genes (miR-124) with the energy metabolism in non-syndromic TOF patients' cardiomyocyte. Furthermore, the study investigated the correlation between the primary miR-124 (rs531564) polymorphism and CHD susceptibility in 432 sporadic patients and 450 controls from two different altitude provinces (city) in China. Our study indicated that the minor C allele of rs531564 correlated with reduced risk of CHD in the low altitude city. Besides, the C allele has elevated frequency in the high-altitude group. Therefore, our findings suggest that the minor C allele of rs531564 SNP may be involved in the reduction of the risk of CHD in a way that interacts with the intrauterine hypoxic environmental factors.

Rs531564 polymorphism in microRNA-214 regulates interleukin-6R expression in anal fissure patients to affect the risk of anal abscess formation

BACKGROUND

Anal abscess is an important complication of anal fissure (AF), whereas interleukin-6R (IL-6R) has been implicated in the development of abscess. In this study, we aimed to explore the possible molecular mechanisms underlying the regulatory effects of miRNAs on IL-6R and other inflammatory factors related to the induction of anal abscess in AF.

METHODS

Bioinformatics analysis, luciferase assay, real-time polymerase chain reaction, and Western blot analysis were performed to identify the possible regulatory relationships between IL-6R and miR-124/miR-125a by comparing the differentiated expression of miR-125a, miR-124, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and IL-4 among different groups of AF patients.

RESULTS

IL-6R messenger RNA (mRNA) was identified as a target gene of miR-124 because the luciferase activity in cells cotransfected with wild-type IL-6R and miR-124 mimics was significantly reduced. In addition, the expression of IL-6R mRNA and protein was significantly inhibited in the presence of miR-124 or an IL-6R inhibitor, confirming the presence of a negative regulatory relationship between miR-124 and IL-6R. Moreover, miR-124 and inflammatory factors were differentially expressed in AF patients carrying different genotypes of rs531564 polymorphism.

CONCLUSIONS

miR-124 and inflammatory factors TNF-α, IFN-γ, and IL-4 may be used as indicators of anal abscess development in AF patients. In addition, miR-124 polymorphism rs531564 is involved with the pathogenesis of anal abscess in AF patients, and the presence of rs531564 may increase the incidence of anal abscess via upregulating the expression of IL-6R, TNF-α, IFN-γ, and IL-4.

The microRNApolymorphisms inmiR-150 and miR-1179 are associated with risk of idiopathic recurrent pregnancy loss

RESEARCH QUESTION

Are single nucleotide polymorphisms of microRNAs (miRNAs) and risk of idiopathic recurrent pregnancy loss (RPL) associated?

DESIGN

A total 375 patients with idiopathic RPL (age, mean ± standard deviation [SD] 33.02 ± 4.24 years; body mass index [BMI], mean ± SD, 21.57 ± 3.70 kg/m²) and 276 control participants (age, mean ± SD, 33.01 ± 5.27 years; BMI, mean ± SD, 21.58 ± 3.20) were recruited. Pregnancy loss was diagnosed using human chorionic gonadotrophin concentrations, ultrasonography and/or physical examination prior to 20 weeks of gestation. The genotype of the participants was determined by polymerase chain reaction restriction fragment length polymorphism analysis. Statistical analysis was performed to investigate the differences in frequencies between the control and RPL genotypes RESULTS: The miR-150G>A heterozygous genotype was significantly associated with increased risk of RPL (adjusted odds ratio 2.502, 95% confidence interval 1.555-4.025; P = 0.0002). The miR-1179A>T heterozygous genotype was significantly associated with decreased risk of RPL (adjusted odds ratio 0.633, 95% confidence interval 0.454-0.884; P = 0.007). Some allele combinations that included miR-150A or miRNA-1179T resulted in an increase or decrease in risk of RPL, respectively.

CONCLUSIONS

The miR-150G>A and miR-1179A>T polymorphisms were more frequently associated with RPL compared with controls.

miR-124, a potential therapeutic target in colorectal cancer

Recently, miR-124 has been regarded as a critical modulator of colorectal cancer. We here summarize the studies on the role and mechanism of miR-124 in colorectal cancer. They indicate that miR-124 is methylated during carcinogenesis and functions as a tumor-suppressor in colorectal cancer. miR-124 might serve as a potential diagnostic biomarker and therapeutic target in colorectal cancer in the foreseeable future.

Epigenetic Regulation by lncRNAs: An Overview Focused on UCA1 in Colorectal Cancer

Colorectal cancers have become the second leading cause of cancer-related deaths. In particular, acquired chemoresistance and metastatic lesions occurring in colorectal cancer are a major challenge for chemotherapy treatment. Accumulating evidence shows that long non-coding (lncRNAs) are involved in the initiation, progression, and metastasis of cancer. We here discuss the epigenetic mechanisms through which lncRNAs regulate gene expression in cancer cells. In the second part of this review, we focus on the role of lncRNA Urothelial Cancer Associated 1 (UCA1) to integrate research in different types of cancer in order to decipher its putative function and mechanism of regulation in colorectal cancer cells. UCA1 is highly expressed in cancer cells and mediates transcriptional regulation on an epigenetic level through the interaction with chromatin modifiers, by direct regulation via chromatin looping and/or by sponging the action of a diversity of miRNAs. Furthermore, we discuss the role of UCA1 in the regulation of cell cycle progression and its relation to chemoresistance in colorectal cancer cells.

Polymorphisms in non-coding RNAs and risk of colorectal cancer: A systematic review and meta-analysis

Colorectal cancer (CRC) has been regarded as a common cancer due to its prevailing incidence in both males and females. Recently, non-coding RNAs used as biomarkers for screening, diagnosis and prognosis of different cancers have been under the focus of attention. As a result of this, the aim of this study was to systematically review articles that investigated the SNPs in genes related to microRNAs and long non-coding RNAs to assess the genetic susceptibility of colorectal cancer risk. The outcome is presented as the results of a meta-analysis. We systematically searched PubMed, Web of Science, and Scopus to identify relevant studies published up to 20/5/2017. These included eligible studies consisting of 23,581 patients and 22,697 controls. The conferred risk was estimated and presented using odds ratios (ORs) and 95% confidence intervals (CI). The Hardy-Weinberg equilibrium (HWE) was assessed by the goodness-of-fit chi-square test in all studies. The power of each study was also calculated based on the available results. Out of 27 different microRNAs which had published results, although most of the studies were under powered, miR-146a and miR-196a were amongst the most studied microRNAs. For five miRNAs (miR-196a, miR-146a, miR-27a, miR-499 and miR-149) which we performed a meta-analysis, miR-27a and miR-149 gene polymorphisms were associated with susceptibility to CRC. Other miRNAs did not show any effect on the CRC risk. Overall, significant association between miR-149 rs2292832 and susceptibility to cancer was identified in a recessive genetic model, TT/ (TC + CC) (OR = 1.19, 95% CI = 1.02-1.39, P = 0.02). On the other hand, rs895819 (miR-27a) GG carriers were more susceptible to CRC (OR = 1.47, 95% CI = 1.21-1.78, P = <0.05) in a recessive genetic model. Analysis of the data based on race revealed that rs2910164 (miR-146a) polymorphism may decrease the risk of CRC among Europeans, in a co dominant model [OR = 0.81, 95% CI 0.66-0.99, p = 0.04], but not among Asians. In conclusion, certain miRNAs (miR-27a and miR-149) may affect the CRC risk and can be regarded as genetic markers amongst different populations. LncRNAs still have to be studied more to reach a conclusion for their association with CRC risk.

Influence of single nucleotide polymorphisms in pri-miR-124-1 and STAT3 genes on gastric cancer susceptibility

INTRODUCTION

MicroRNAs (miRNAs) are small ribonucleic acids that modulate the expression of downstream target genes. There is considerable evidence of their involvement in many malignancies, such as oesophageal and gastric. We hypothesised altered expressions of pri-miR-124-1 rs531564 and STAT3 rs1053023 polymorphisms in gastric cancer.

MATERIALS AND METHODS

Genomic DNA was extracted from peripheral blood of 250 patients with gastric cancer and 310 healthy individuals. The RFLP method was applied for determination of pri-miR-124 polymorphism and the AS-PCR method for STAT3 polymorphism.

RESULTS

The distribution of rs531564 genotypes in cases and controls was different: the G allele carriers had a reduced gastric cancer risk (OR = 0.62; 95%CI = 0.49-0.80, P = 0.0002). Presence of the minor allele of STAT3 (rs1053023) was linked with higher risk of gastric cancer (OR = 2.29; 95% CI = 1.79-2.93, P < 0.0001). Compared with the most frequent haplotype C-G [the SNP order was pri-miR-124-1 (rs531564) and STAT3 (rs1053023)] in controls, C-A haplotype was associated with a significantly increased risk of gastric cancer (OR = 2.28; 95%CI = 1.64-3.09, P < 0.0001).

CONCLUSION

There is a strong link between pri-miR-124-1 rs531564 and STAT3 rs1053023 and gastric cancer that may be pathogenic, and so worthy of further investigation.

Comprehensive Assessment of the Relationship Between MicroRNA-124 and the Prognostic Significance of Cancer

BACKGROUND

Numerous studies have demonstrated the presence of microRNA-124 abnormalities involving gene expression, methylation, and single nucleotide polymorphism (SNP) in multiple and diverse cancers, but the prognostic value of these abnormalities in cancer remains inconclusive.

OBJECTIVE

The aim of this study is to determine the prognostic value of miR-124 in cancer.

METHODS

We scrutinized the electronic databases and estimate the association between miR-124 expression, methylation and single nucleotide polymorphisms (SNPs), and prognosis in cancers. The pooled hazard ratios with 95% confidence intervals (CIs) for overall survival (OS), and disease-free survival/recurrence-free survival (RFS)/progression-free survival (PFS) were calculated to estimate the effects of miR-124 expression, methylation, and SNPs on cancer prognosis. The Quality in Prognosis Studies and Newcastle-Ottawa Scale were utilized to assess the quality of included studies.

RESULTS

A total of 20 studies involving 3,574 participants were analyzed in evidence synthesis. Our findings showed that the low expression of miR-124 was significantly associated with poor OS (HR = 2.37, 95% CI: 1.91-2.94, P = 0.00; HR = 3.10, 95% CI: 2.04-4.70, P = 0.00) and PFS/RFS (HR = 2.21, 95% CI: 1.50-3.26, P = 0.00; HR = 2.12, 95% CI: 1.20-3.74, P = 0.00). The hyper-methylation of miR-124 was associated with poor OS (HR = 2.09, 95% CI: 1.48-2.95, P = 0.00) and PFS (HR = 3.70, 95% CI: 1.72-7.97, P = 0.00) (Table 3). The patients carrying with Allele C of miR-124 rs5315649 had a worse OS (HR = 1.50, 95% CI: 1.09-2.07, P = 0.00) and PFS (HR = 1.67, 95% CI: 1.20-2.33, P = 0.00) than the carriers with Allele G.

CONCLUSION

The low expression and hyper-methylation of miR-124 was strongly associated with poor prognosis, and genetic variations of miR-124 rs531564 affected prognosis in cancer patients.

Association between miR-124-1 rs531564 polymorphism and risk of cancer: An updated meta-analysis of case-control studies

Many studies examined the association between miR-124-1 rs531564 polymorphism and the risk of some human cancers, but the findings remain controversial. This update meta-analysis aimed to validate the association between rs531564 polymorphism of miR-124-1 and cancer risk. Eligible studies including 6,502 cancer cases and 7,213 controls were documented by searching Web of Science, PubMed, Scopus, and Google scholar databases. Pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were estimated to quantitatively evaluate the association between rs531564 variant and cancer risk. The results indicated that rs531564 variant significantly decreased the risk of cancer in homozygous codominant (OR=0.54, 95 % CI=0.43-0.69, p<0.00001, GG vs CC), dominant (OR=0.84, 95 % CI=0.72-0.99, p=0.03, CG+GG vs CC), recessive (OR=0.65, 95 % CI=0.54-0.78, p<0.00001, GG vs CG+CC), and allele (OR=0.84, 95 % CI=0.73-0.96, p=0.008, G vs C) genetic model. Stratified analysis by cancer type revealed that rs531564 variant was associated with gastric cancer, cervical cancer, esophageal squamous cell carcinoma and colorectal cancer risk. In summary, the findings of this meta-analysis support an association between miR-124-1 rs531564 polymorphism and cancer risk. Larger and well-designed studies are required to estimate this association in detail.

mRNA-miRNA bipartite network reconstruction to predict prognostic module biomarkers in colorectal cancer stage differentiation

Biomarker detection is one of the most important and challenging problems in cancer studies. Recently, non-coding RNA based biomarkers such as miRNA expression levels have been used for early diagnosis of many cancer types. In this study, a systems biology approach was used to detect novel miRNA based biomarkers for CRC diagnosis in early stages. The mRNA expression data from three CRC stages (Low-grade Intraepithelial Neoplasia (LIN), High-grade Intraepithelial Neoplasia (HIN) and Adenocarcinoma) were used to reconstruct co-expression networks. The networks were clustered to extract co-expression modules and detected low preserved modules among CRC stages. Then, the experimentally validated mRNA-miRNA interaction data were applied to reconstruct three mRNA-miRNA bipartite networks. Twenty miRNAs with the highest degree (hub miRNAs) were selected in each bipartite network to reconstruct three bipartite subnetworks for further analysis. The analysis of these hub miRNAs in the bipartite subnetworks revealed 30 distinct important miRNAs as prognostic markers in CRC stages. There are two novel CRC related miRNAs (hsa-miR-190a-3p and hsa-miR-1277-5p) in these 30 hub miRNAs that have not been previously reported in CRC. Furthermore, a drug-gene interaction network was reconstructed to detect potential candidate drugs for CRC treatment. Our analysis shows that the hub miRNAs in the mRNA-miRNA bipartite network are very essential in CRC progression and should be investigated precisely in future studies. In addition, there are many important target genes in the results that may be critical in CRC progression and can be analyzed as therapeutic targets in future research.

Association of microRNA-423 rs6505162 C>A polymorphism with susceptibility and metastasis of colorectal carcinoma

Studies have evaluated the association between the SNP miRNA-423 rs6505162 C>A and cancer risk in several cancers with contradictory outcomes. It was reported that miRNA-423 rs6505162 C>A polymorphism was associated with the overall survival and the recurrence-free survival of colorectal carcinoma. However, no studies have reported the association between miRNA-423 rs6505162 C>A polymorphism and susceptibility of colorectal carcinoma.In this study, we investigated the association between miRNA-423 polymorphism with risk and clinicopathological parameters of colorectal carcinoma. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to genotype 117 colorectal carcinoma patients and 84 healthy controls.Our data indicated the frequencies of rs6505162 genotypes and alleles were significantly different between colorectal carcinoma patients and controls. Compared with CC homozygote, the AC heterozygote exhibited a significantly decreased risk of colorectal carcinoma; and the combination of AC and AA genotype was associated with decreased risk of colorectal carcinoma. The allele distribution of rs6505162 was significantly different between cases and controls. Furthermore, miR-423 rs6505162 C>A genotype showed a significant association with metastasis in patients (P = .022).Our study suggested that miR-423 rs6505162 C>A polymorphism was associated with the susceptibility and metastasis of colorectal carcinoma, and that miR-423 rs6505162 C>A polymorphism might be a potential biomarker for colorectal carcinoma.

A Genetic Variant in miR-124 Decreased the Susceptibility to Esophageal Squamous Cell Carcinoma in a Chinese Kazakh Population

AIMS

Esophageal squamous cell carcinoma (ESCC) is characterized by high prevalence and mortality worldwide, and it is very highly prevalent in China. ESCC is caused by various factors, including microRNAs (miRNAs) whose expression have been shown to play a major role in tumor generation. Single nucleotide polymorphisms (SNPs) in miRNAs could affect susceptibility to numerous cancers. This study aimed to evaluate the relationship between SNPs in miR-124 and ESCC risk in the Chinese Kazakh population.

METHODS

A total of 239 Chinese Kazakh patients with ESCC and 227 healthy Chinese Kazakh individuals were recruited in this study. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to analyze the miR-124 rs531564 genotype.

RESULTS

Allele G of the miR-124 rs531564 polymorphism significantly reduced the risk of ESCC in the Chinese Kazakh population [odds ratio (OR) = 0.711; 95% confidence interval (CI): 0.508-0.996; p = 0.047]. The dominant model indicated that the CG+GG genotypes were associated with significantly decreased ESCC risk compared to the CC genotype (adjusted OR = 0.586; 95% CI: 0.396-0.867; p = 0.007). Stratification analyses showed that compared with the CC genotype, the CG and CG+GG genotypes manifested reduced ESCC risks in the female group [CG vs. CC: OR = 0.472; 95% CI: 0.255-0.872; p = 0.016; (CG+GG) vs. CC: OR = 0.472; 95% CI: 0.255-0.872; p = 0.016] and the age group of <57 years old [CG vs. CC: OR = 0.456; 95% CI: 0.258-0.806; p = 0.006; (CG+GG) vs. CC: OR = 0.456; 95%CI: 0.258-0.806; p = 0.006]. The miR-124 rs531564 polymorphism showed no significant association with histological stage, lymph node metastasis, depth of invasion, or tumor/node/metastasis stage.

CONCLUSIONS

Our findings are the first to be reported that the miR-124 rs531564 polymorphism decreased ESCC risk in the Chinese Kazakh population.

Polymorphisms in MIR122, MIR196A2, and MIR124A Genes are Associated with Clinical Phenotypes in Inflammatory Bowel Diseases

BACKGROUND

Inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis (UC), are multifactorial disorders that result from a dysregulated inflammatory response to environmental factors in genetically predisposed individuals. Recently, microRNAs (miRNAs) have been shown to be involved in the development of IBDs.

AIMS

We investigated common variants in five miRNA genes in a cohort of Italian IBD patients, to evaluate their possible role in the disease's susceptibility and phenotype manifestations.

METHODS

The analysis included 267 CD patients, 207 UC patients, and 298 matched healthy controls. Polymorphisms in the MIR122, MIR499, MIR146A, MIR196A2, and MIR124A genes were evaluated by allelic discrimination assay.

RESULTS

We did not find associations between mir polymorphisms and IBD susceptibility. In both diseases, rs17669 and rs11614913 (MIR122 and MIR196A2) seem to contribute to clinical phenotypes: ileal location in CD (odds ratio [OR] = 1.82, p = 0.03; OR = 0.51, p = 0.01), and left-sided extent in UC (OR = 0.43, p = 0.05; OR = 0.28, p = 0.002). In CD, the MIR124A polymorphism (rs531564) contributed to colon location (p = 0.03, OR = 2.74). Finally, the variant allele of rs11614913 was associated with early age at onset in both diseases (p = 0.05 and p = 0.02).

CONCLUSIONS

We showed for the first time that polymorphisms in MIR122, MIR196A2, and MIR124A could play a role in clinical phenotype modulation in IBD.

Lentivirus-mediated microRNA-124 gene-modified bone marrow mesenchymal stem cell transplantation promotes the repair of spinal cord injury in rats

Our study aims to explore the effects of lentivirus-mediated microRNA-124 (miR-124) gene-modified bone marrow mesenchymal stem cell (BMSC) transplantation on the repair of spinal cord injury (SCI) in rats. BMSCs were isolated from the bone marrow of rats. The target gene miR-124 was identified using a luciferase-reporter gene assay. Seventy-two rats were selected for construction of the SCI model, and the rats were randomly divided into the blank group, sham group, SCI group, negative control (NC) group, overexpressed miR-124 group and si-PDXK group. The mRNA expression of miR-124 and the mRNA and protein expression of pyridoxal kinase (PDXK) were detected by quantitative real-time polymerase chain reaction and western blotting. The locomotor capacity of the rats was evaluated using the Basso, Beattie and Bresnahan (BBB) scale. Brdu, neuron-specific enolase (NSE), neurofilament (NF) and microtubule-associated protein 2 (MAP2) were detected using immunohistochemistry. The expression levels of thyrotropin-releasing hormone (TRH), prostacyclin (PGI2) and gangliosides (GM) were measured using an enzyme-linked immunosorbent assay. PDXK was identified as the target gene of miR-124. The overexpressed miR-124 group exhibited higher miR-124 expression than the SCI, NC and si-PDXK groups. Compared with the SCI and NC groups, the PDXK expression was downregulated in the overexpressed miR-124 and si-PDXK groups, and the BBB scores were significantly increased 7, 21 and 35 days after transplantation. The double-labeled positive cell densities (Brdu+NSE/NF/MAP2) and the expression levels of TRH, PGI2 and GM in the overexpressed miR-124 group were significantly higher than those in the NC and SCI groups. These results indicated that miR-124 targeted PDXK to accelerate the differentiation of BMSCs into neurocytes and promote SCI repair.

Pri-microRNA-124 rs531564 polymorphism minor allele increases the risk of pulmonary artery hypertension by abnormally enhancing proliferation of pulmonary artery smooth muscle cells

MicroRNA-124 (miR-124) has been reported to be downregulated in the cells exposed to hypoxia, which was confirmed in our study. We then used online microRNA target prediction tools to identify GRB2, SMAD5, and JAG1 as the candidate target genes of miR-124, and we next validated GRB2 as a direct gene by using luciferase reporter system. We also established the regulatory relationship between miR-124 and GRB2 by showing the negative linear relationship between GRB2 and miR-124 expression. Furthermore, we investigated the miR-124 and GRB2 expression levels of different genotypes including CC (n=30), GC (n=18), and GG (n=4), which supported the hypothesis that the presence of minor allele (C) of rs531564 polymorphism compromised the expression of miR-124. Meanwhile, we also conducted real-time polymerase chain reaction and Western blot analysis to study the expression of GRB2 among different genotypes or pulmonary artery smooth muscle cells (PASMCs) treated with miR-124 mimics, GRB2 small interfering RNA, and miR-124 inhibitors, respectively, and found that introduction of miR-124 or GRB2 small interfering RNA could reduce the expression of GRB2 and inhibit the proliferation of PASMCs, while miR-124 upregulated the expression of GRB2 and promoted the proliferation of PASMCs. A total of 412 COPD patients with PAH (n=182) or without PAH (n=230) were recruited in this study, and more individuals carrying at least one minor allele of rs531564 were found in the COPD patients with PAH than in those without PAH (odds ratio: 0.61, 95% confidence interval: 0.41–0.91; P=0.166). In conclusion, the presence of rs531564 minor allele may increase the risk of PAH in COPD by reducing miR-124 expression, increasing GRB2 expression, and promoting the proliferation of PASMCs.

Validation of microRNA pathway polymorphisms in esophageal adenocarcinoma survival

Polymorphisms in miRNA and miRNA pathway genes have been previously associated with cancer risk and outcome, but have not been studied in esophageal adenocarcinoma outcomes. Here, we evaluate candidate miRNA pathway polymorphisms in esophageal adenocarcinoma prognosis and attempt to validate them in an independent cohort of esophageal adenocarcinoma patients. Among 231 esophageal adenocarcinoma patients of all stages/treatment plans, 38 candidate genetic polymorphisms (17 biogenesis, 9 miRNA targets, 5 pri-miRNA, 7 pre-miRNA) were genotyped and analyzed. Cox proportional hazard models adjusted for sociodemographic and clinicopathological covariates helped assess the association of genetic polymorphisms with overall survival (OS) and progression-free survival (PFS). Significantly associated polymorphisms were then evaluated in an independent cohort of 137 esophageal adenocarcinoma patients. Among the 231 discovery cohort patients, 86% were male, median diagnosis age was 64 years, 34% were metastatic at diagnosis, and median OS and PFS were 20 and 12 months, respectively. GEMIN3 rs197412 (aHR = 1.37, 95%CI: [1.04-1.80]; P = 0.02), hsa-mir-124-1 rs531564 (aHR = 0.60, 95% CI: [0.53-0.90]; P = 0.05), and KIAA0423 rs1053667 (aHR = 0.51, 95% CI: [0.28-0.96]; P = 0.04) were found associated with OS. Furthermore, GEMIN3 rs197412 (aHR = 1.33, 95% CI: [1.03-1.74]; P = 0.03) and KRT81 rs3660 (aHR = 1.29, 95% CI: [1.01-1.64]; P = 0.04) were found associated with PFS. Although none of these polymorphisms were significant in the second cohort, hsa-mir-124-1 rs531564 and KIAA0423 rs1053667 had trends in the same direction; when both cohorts were combined together, GEMIN3 rs197412, hsa-mir-124-1 rs531564, and KIAA0423 rs1053667 remained significantly associated with OS. We demonstrate the association of multiple miRNA pathway polymorphisms with esophageal adenocarcinoma prognosis in a discovery cohort of patients, which did not validate in a separate cohort but had consistent associations in the pooled cohort. Larger studies are required to confirm/validate the prognostic value of these polymorphisms in esophageal adenocarcinoma.

Single nucleotide polymorphism of hsa-miR-124a affects risk and prognosis of osteosarcoma

OBJECTIVE

To study the correlation between single nucleotide polymorphism (SNP) of hsa-miR-124a and risk and prognosis of osteosarcoma (OS).

METHODS

OS patients (n = 174) hospitalized at The Second Affiliated Hospital of Harbin Medical University from January 2010 to March 2012 were selected as case group by inclusion and exclusion criteria, and healthy people (n = 150) receiving physical examination at the same duration were recruited as control group. Polymerase chain reaction-ligase detection reaction (PCR-LDR) was performed for genotyping of hsa-miR-124a rs531564.

RESULTS

There were significant differences in the frequency distribution of genotypes and alleles of hsa-miR-124a rs531564 in the case and control group (all P < 0.05); the individuals carrying with CG + GG genotype showed significantly decreased risk for OS. The clinical pathological characteristics were significantly different in the patients with CC genotype and CG + GG genotype, including tumor size, tumor differentiation grading, Enneking staging, operation manner, time of chemotherapy and metastasis (all P < 0.05). The 5-year survival rate of the cases with CC genotype was significantly lower than that of the ones with CG + GG genotype (P < 0.05). CG + GG genotype, Enneking staging and operation manner were independent risk factors for prognosis of OS (all P < 0.05).

CONCLUSIONS

CG +$ GG genotype of hsa-miR-124a rs531564 had decreased risk for OS and affected prognosis of OS.