Functional variant in microRNA-196a2 contributes to the susceptibility of congenital heart disease in a Chinese population

A variant in microRNA-196a2 is associated with susceptibility to hepatocellular carcinoma in Chinese patients with cirrhosis

AIMS

Cirrhosis is an important risk factor for hepatocellular carcinoma (HCC) in China, while little is known of the genetic susceptibility to hepatocarcinogenesis. Traditional approaches to identification of novel genetic predisposition genes have focused on protein encoding genes. There is evidence to suggest that microRNAs (miRNA) may play an important role in tumorigenesis. Recent studies have implicated that the rs11614913 SNP in miR-196a2 may be associated with susceptibility to lung cancer, congenital heart disease, breast cancer, as well as reduced survival in non-small cell lung cancer. This study aims to assess whether this functional polymorphism can influence susceptibility to and the progression of cirrhosis-related HCC.

METHODS

532 patients with hepatic cirrhosis (310 patients with HCC and 222 patients without HCC) were enrolled. DNA was extracted from blood specimens, and miR-196a2 polymorphism was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In addition, tumour tissues of liver (n=59) were obtained from the studied HCC patients for measurement of miR-196a expression levels.

RESULTS

The frequency of the CC genotype among HCC patients was higher than that in the control group, implying that the cirrhotic patients with the CC genotype or C allele containing genotypes (CT and CC) may have a higher risk of HCC. However, in a subsequent analysis of the association between this polymorphism and clinicopathological characteristics, there was an association between rs11614913 genotype and tumour size (p=0.046), but not with tumour number, grade, stage, invasiveness or Child-Pugh grade. In a genotype-phenotype correlation analysis using 59 tumour tissues of liver, rs11614913 CC or carrying at least one C allele was associated with significantly increased mature miR-196a expression (p=0.006 or =0.002).

CONCLUSIONS

Our results suggest, for the first time, that miR-196a2 polymorphism may contribute to cirrhosis-related HCC susceptibility in Chinese patients through influencing mature miR-196a expression.

Common genetic polymorphisms in pre-microRNAs and risk of cervical squamous cell carcinoma

MicroRNAs (miRNAs) function as gene regulator and they participate in diverse biological pathways. Common single nucleotide polymorphisms (SNPs) in pre-microRNAs may change their property through altering miRNAs expression and/or maturation. We conducted a pilot study to test whether SNPs in pre-microRNAs were associated with cervical squamous cell carcinoma (CSCC). Genotypes of three SNPs in pre-miRNAs (hsa-miR-196a2 rs11614913 C/T, hsa-miR-499 rs3746444 A/G, and hsa-miR-146a rs2910164 G/C) in 226 CSCC patients and 309 control subjects were determined with the use of PCR-restriction fragment length polymorphism (RFLP) assay. Significantly increased CSCC risks were found to be associated with G allele of rs3746444 and G allele of rs2910164 (P = 0.017, OR = 1.454, and P = 0.016, OR = 1.355, respectively). Increased CSCC risks were associated with them in different genetic model (P = 0.0004, OR = 1.98 for rs3746444 in an overdominant model, and P = 0.024, OR = 2.10 for rs2910164 in a codominant model, respectively). Results of stratified analyses revealed that rs2910164 is associated with tumor differentiation and lymph node status (P = 0.043, OR = 2.08, and a borderline P = 0.057, OR = 0.41, respectively). No association between rs11614913 and CSCC risk was observed. The present study provides evidence that rs3746444 and rs2910164 are associated with CSCC, indicating that common genetic polymorphisms in pre-microRNAs contribute to the pathogenesis of CSCC.

Polymorphisms affecting micro-RNA regulation and associated with the risk of dietary-related cancers: a review from the literature and new evidence for a functional role of rs17281995 (CD86) and rs1051690 (INSR), previously associated with colorectal cancer

In this review, we focus on the genetic variations (single nucleotide polymorphisms, SNPs) known to occur in microRNAs and in their binding sites and the susceptibility to cancers of the gastro-intestinal (GI) tract in humans. Since the sequence complementarity and the thermodynamics of binding play an essential role in the interaction of miRNA with its target mRNA, sequence variations in the miRNA-binding seed regions or in miRNA genes (either within pre-, pri-, or mature miRNA regions) should reinforce, weaken, or disrupt the miRNA-mRNA interaction and affect the expression of mRNA targets. Indirect evidences supporting these hypotheses are reported in the literature, essentially coming from case-control association studies. Several studies have been published on the association between miR-SNPs or SNPs within their binding sites and the risk of oesophageal, gastric, or colorectal cancer. Unfortunately, functional studies are lacking. Besides reviewing the available literature, we present here for the first time two SNPs (rs17281995 in CD86 and rs1051690 in INSR) previously associated with the risk of CRC in a Czech population are also associated with the risk in a Spanish population. Moreover, we show for the first time that both these alleles regulate differentially the amount of a reporter gene (luciferase) in an in vitro assay on HeLa cells. These findings suggest that both these SNPs may have a functional role in regulating the expression of CD-86 and INSR proteins acting at the level of the 3'UTR. More functional studies are needed in order to better understand the role of polymorphic regulatory sequences at the 3'UTR of genes.

Association study of common genetic variants in pre-microRNAs in patients with ulcerative colitis

BACKGROUND

Common single-nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human diseases. We evaluated the associations of three SNPs (rs11614913, rs2910164, and rs3746444) in pre-miRNAs (miR-196a2, miR-146a, and miR-499) with the risk of ulcerative colitis (UC) in a Japanese population.

METHODS

The rs11614913 (T > C), rs2910164 (C > G), and rs3746444 (A > G) SNPs were genotyped in 170 UC and 403 control subjects.

RESULTS

The rs3746444 AG genotype was significantly higher among the UC group (odds ratio (OR) = 1.51, 95% CI = 1.03-2.21, p = 0.037). The rs3746444 AG genotype was associated with onset at an older age (OR = 1.70, 95% CI = 1.04-2.78, p = 0.035), left-sided colitis and pancolitis (left-sided colitis, OR = 2.10, 95% CI = 1.12-3.94, p = 0.024; pancolitis, OR = 1.81, 95% CI = 1.09-3.01, p = 0.028, left-sided colitis + pancolitis, OR = 1.91, 95% CI = 1.26-2.92, p = 0.003), higher number of times hospitalized (OR = 2.63, 95% CI = 1.22-5.69, p = 0.017), steroid dependence (OR = 2.63, 95% CI = 1.27-5.44, p = 0.014), and refractory phenotypes (OR = 2.76, 95% CI = 1.46-5.21, p = 0.002) while the rs3746444 AA genotype was inversely associated with the number of times hospitalized (2∼, OR = 0.36, 95% CI = 0.17-0.79, p = 0.012), steroid dependence (OR = 0.42, 95% CI = 0.21-0.88, p = 0.021), and refractory phenotypes (OR = 0.38, 95% CI = 0.20-0.72, p = 0.003). The rs1161913 TT genotype also held a significantly higher risk of refractory phenotype (T/T vs. T/C + C/C, OR = 2.21, 95% CI = 1.17-4.18, p = 0.016).

CONCLUSIONS

Our results provided the first evidence that rs3746444 SNP may influence the susceptibility to UC, and both rs3746444 and rs11614913 SNPs may influence the pathophysiological features of UC.

Association study of common genetic variants in pre-microRNAs in patients with ulcerative colitis

BACKGROUND

Common single-nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human diseases. We evaluated the associations of three SNPs (rs11614913, rs2910164, and rs3746444) in pre-miRNAs (miR-196a2, miR-146a, and miR-499) with the risk of ulcerative colitis (UC) in a Japanese population.

METHODS

The rs11614913 (T > C), rs2910164 (C > G), and rs3746444 (A > G) SNPs were genotyped in 170 UC and 403 control subjects.

RESULTS

The rs3746444 AG genotype was significantly higher among the UC group (odds ratio (OR) = 1.51, 95% CI = 1.03-2.21, p = 0.037). The rs3746444 AG genotype was associated with onset at an older age (OR = 1.70, 95% CI = 1.04-2.78, p = 0.035), left-sided colitis and pancolitis (left-sided colitis, OR = 2.10, 95% CI = 1.12-3.94, p = 0.024; pancolitis, OR = 1.81, 95% CI = 1.09-3.01, p = 0.028, left-sided colitis + pancolitis, OR = 1.91, 95% CI = 1.26-2.92, p = 0.003), higher number of times hospitalized (OR = 2.63, 95% CI = 1.22-5.69, p = 0.017), steroid dependence (OR = 2.63, 95% CI = 1.27-5.44, p = 0.014), and refractory phenotypes (OR = 2.76, 95% CI = 1.46-5.21, p = 0.002) while the rs3746444 AA genotype was inversely associated with the number of times hospitalized (2∼, OR = 0.36, 95% CI = 0.17-0.79, p = 0.012), steroid dependence (OR = 0.42, 95% CI = 0.21-0.88, p = 0.021), and refractory phenotypes (OR = 0.38, 95% CI = 0.20-0.72, p = 0.003). The rs1161913 TT genotype also held a significantly higher risk of refractory phenotype (T/T vs. T/C + C/C, OR = 2.21, 95% CI = 1.17-4.18, p = 0.016).

CONCLUSIONS

Our results provided the first evidence that rs3746444 SNP may influence the susceptibility to UC, and both rs3746444 and rs11614913 SNPs may influence the pathophysiological features of UC.

Common genetic polymorphisms in pre-microRNAs were associated with increased risk of dilated cardiomyopathy

BACKGROUND

Common single nucleotide polymorphisms (SNPs) in pre-microRNAs may change their property through altering microRNAs (miRNAs) expression and/or maturation, resulting diverse functional consequences. We conducted a pilot study to test whether SNPs in pre-microRNAs were associated with dilated cardiomyopathy (DCM).

METHODS

Genotypes of 3 SNPs in pre-miRNAs (has-mir-196a2 rs11614913 C/T, hsa-mir-499 rs3746444 A/G, hsa-mir-146a rs2910164 C/G) in 221 DCM patients and 321 control subjects were determined with the use of PCR-restriction fragment length polymorphism (RFLP) assay.

RESULTS

Significantly increased DCM risks were found to be associated with variant allele of has-mir-196a2 rs11614913 C/T (T allele) and hsa-mir-499 rs3746444 A/G (G allele) (P<0.0001, OR=1.730, 95% CI=1.345-2.227, and P<0.0001, OR=1.794, 95% CI=1.350-2.385, respectively). We found that increased DCM risk was statistically significantly associated with these 2 SNPs in a dominant model (P=0.0001 and P<0.0001 for rs11614913 and rs3746444, respectively). No association between DCM risk and hsa-mir-146a rs2910164 C/G was observed (P=0.451, OR=1.102, 95% CI=0.856-1.418).

CONCLUSIONS

Both the has-mir-196a2 rs11614913 C/T and hsa-mir-499 rs3746444 A/G, but not hsa-mir-146a rs2910164 C/G, are associated with a significantly increased risk of DCM, indicating that common genetic polymorphisms in pre-microRNAs are associated with DCM.

Association of a variant in MIR 196A2 with susceptibility to hepatocellular carcinoma in male Chinese patients with chronic hepatitis B virus infection

MicroRNAs (miRNAs) are small noncoding RNAs with regulatory functions as tumor suppressors and oncogenes. Recent studies have implicated that the rs11614913 SNP in MIR196A2 was associated with susceptibility of lung cancer, congenital heart disease, breast cancer and shortened survival time of nonsmall cell lung cancer. To assess whether this polymorphism is associated with susceptibility to and clinicopathologic characteristics of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), a total of 560 patients with chronic HBV infection and 391 healthy volunteers were enrolled, and MIR196A2 polymorphism was genotyped by polymerase chain reaction-ligation detection reaction (PCR-LDR). In our study group, there was no significant association between MIR196A2 polymorphism and the risk of HBV-related HCC in all subjects, however, the risk of HCC was significantly higher with MIR196A2 rs11614913 CC genotype or C allele compared with those with the TT genotype or T allele in male patients. Furthermore, in a subsequent analysis of the association between this polymorphism and clinicopathologic characteristics, there was still no significant difference in both the distribution of genotype or allelic frequency. However, we observed that the T allele was significantly more frequent in male HCC patients with lymphatic metastasis. Our results suggested that MIR196A2 polymorphism was associated with susceptibility to HBV-related HCC in a male Chinese population.

microRNAs in diseases: from candidate to modifier genes

Until recently, the search for genetic factors predisposing or causing Mendelian diseases focused almost exclusively on protein coding sequences. As essential components of the regulatory system of gene expression, microRNAs (miRNAs) hold great promises into elucidating a number of inherited diseases. The herein review focuses on the genetic variations, whether copy number variation (CNV) or single nucleotide polymorphism (SNP), alternatively at the levels of the miRNA gene itself and of its target genes. We consider miRNA as the candidate gene, or the regulator of a disease-causing gene, or the modifier gene. The best paradigms of the field are presented in both monogenic diseases and complex traits. The computational tools, which are essential into identifying miRNAs and characterizing miRNA targets, are overviewed.

Deciphering the molecular basis of venous thromboembolism: where are we and where should we go?

Venous thromboembolism (VTE) is a frequent disease that has a major genetic component of risk. However, known identified genetic risk factors account for <30% of idiopathic (without any environmental origin) VTE cases. This article aims to review the lessons learnt during recent decades in the field of the genetics of VTE, describe the present state-of-art methods and discuss promising themes for finding new susceptibility loci.