The association between two common polymorphisms in MicroRNAs and hepatocellular carcinoma risk in Asian population

MicroRNA polymorphism: A target for diagnosis and prognosis of hepatocellular carcinoma?

Hepatocellular carcinoma (HCC) is a life-threatening cancer of the digestive system, with complex pathogenesis affected by a broad spectrum of genetic and epigenetic factors. Among several factors, microRNAs (miRNAs), which are considered regulators of the post-transcriptional gene expression, play important roles in determining the malignant phenotype of HCC. In recent years, the advances in molecular genetics have resulted in the characterization of complex genetic factors and in the identification of epigenetic mechanisms of diseases. Accumulating data have suggested that miRNA polymorphisms are involved in tumorigenesis and prognosis, suggesting that the miRNAs may serve as a target for HCC with regard to pathogenesis and prognosis. In the present review, a comprehensive and detailed literature search was conducted and the role of miRNA polymorphisms in the pathogenesis and prognosis of HCC is summarized. The data proposed the use of miRNAs as targets for the diagnosis and treatment of HCC.

Investigation of the Association of miRNA-499, miRNA-146a, miRNA-196a2 Loci with Hepatocellular Carcinoma Risk: A Case-Control Study Involving 1507 Subjects

microRNAs' (miRNAs) loci may influence hepatocellular carcinoma (HCC) development. Many recent studies have assessed the relationship between miRNA-499, miRNA-146a, and miRNA-196a2 loci and HCC risk. However, the observed results are conflicting. A total of 584 HCC patients and 923 age- and sex-matched controls were recruited. The correlation of miRNA-499 rs3746444, miRNA-146a rs2910164, and miRNA-196a2 rs11614913 with HCC development was assessed. In the <53-year-old subgroup, a correlation of the rs2910164 locus with HCC risk was found (GG/CG vs. CC: adjusted p = 0.011, GG vs. CC: adjusted p = 0.021 and CG vs. CC: adjusted p = 0.027). The association between miRNA-146a rs2910164 and the risk of HCC was also found in the never smoking (GG/CG vs. CC: adjusted p = 0.011 and CG vs. CC: adjusted p = 0.018). Using false-positive report probability method and power value, we identified that miRNA-146a rs2910164 conferred a risk to HCC in the <53-year-old and never-smoking subgroups. In conclusion, this study indicates rs2910164 may be a risk factor for HCC, especially in the <53-year-old and never-smoking subgroups.

[Assessment of external risk factors of hepatocellular cancer development and markers of genetic predisposition to its development in the ethnic group of yakut - men]

AIM

To establish the main external and genetically determined risk factors for the development of hepatocellular cancer in the ethnic group of male Yakuts living in the Republic of Sakha (Yakutia) [RS (Y)] in the epidemiologically unfavorable conditions of the incidence of viral hepatitis.

MATERIALS AND METHODS

A total of 97 male Yakuts were examined, including 44 people diagnosed with hepatocellular cancer and 53 people diagnosed with chronic viral hepatitis. HCC risk factors were identified by analyzing medical records and questioning patients. In the experimental and control groups, genetic studies of single nucleotide polymorphisms of genes mapped on the X-chromosome and involved in the activation of antiviral immunity along the TLR7 signaling pathway were performed.

RESULTS AND DISCUSSION

In 100% of patients with hepatocellular cancer, infection with hepatitis B, C, D viruses or co - infection with these agents was detected. Every fourth patient with HCC in the RS (Y) was infected with hepatitis D. The course of hepatocellular cancer associated with HDV was characterized by rapid progression of liver cirrhosis, development of portal hypertension, bleeding from varicose veins of the stomach and esophagus (36.4%) and edematous ascitic syndrome (63.6%). In addition to viral agents, additional risk factors for liver cancer were identified, such as alcohol abuse, overweight, diabetes mellitus, and smoking. Among the studied variation sites of genes localized on the X-chromosome and encoding the reaction of innate antiviral immunity, no genetic marker was found with a sufficient degree of confidence determining the likelihood of hepatocellular cancer developing.

CONCLUSIONS

The high incidence of hepatocellular carcinoma of the male population in the RS (Y) is due to the widespread prevalence of parenteral viral hepatitis, especially viral hepatitis D. Due to the introduction of mass vaccination of the population against hepatitis B in the Russian Federation in the foreseeable future in the RS (Y) we should see a decrease in the proportion of hepatocellular cancer associated with hepatitis B and D viruses, and therefore the focus should be on the treatment and prevention of hepatitis C virus and non - infectious risk factors.

Association of MicroRNA Polymorphisms With Hepatocellular Carcinoma in an Iranian Population

Background

Single nucleotide polymorphisms (SNPs) can modulate various biological processes by influencing microRNA (miRNA) biogenesis and altering target selection. Common SNPs may alter the processing of miRNA and may be associated with hepatocellular carcinoma (HCC). We investigated the relationship between miR-499A>G, miR-149C>T, miR-196a2T>C, and miR-146aG>C and HCC susceptibility, examining the interaction of the miRNAs with hepatitis B virus (HBV).

Methods

We evaluated the associations of miR-499A>G (rs3746444), miR-149C>T (rs2292832), miR-196a2T>C (rs11614913), and miR-146aG>C (rs2910164) with HCC susceptibility in 100 HCC patients (70 males and 30 females) and 120 healthy controls (70 males and 50 females), using the PCR-restriction fragment length polymorphism method.

Results

For miR-499A>G, the frequencies of the AG genotype and G allele were higher in female HCC patients than in female controls (P=0.02 and 0.045, respectively). The frequency of the A allele was higher in HBV-positive HCC patients than in controls (P=0.019). For miR-149C>T, the frequency of the CC genotype was higher in female HCC patients than in female controls (P=0.009). For miR-196a2T>C, the frequencies of the CT and CC genotypes and the C allele were higher in HBV-positive HCC patients than in controls (P<0.001, P=0.009, and P<0.001, respectively). The frequencies of miR-146aG>C polymorphisms did not differ between HCC patients and controls.

Conclusions

miR-499A>G, miR-149C>T, and miR-196a2T>C were associated with the development of HCC in women and/or that of HBV-related HCC. They can be considered genetic risk factors for the development of HCC among Iranians.

Comprehensive Review of Genetic Association Studies and Meta-Analysis on polymorphisms in microRNAs and Urological Neoplasms Risk

Gene expression is negatively regulated by microRNAs (miRNAs), which commonly act as tumor oncogenes or suppressors. Previous results were inconsistent concerning the relationship between polymorphisms in miRNAs and risk of urological neoplasms. Here, we conducted a comprehensive literature research on diverse databases aiming at enrolling all eligible studies up to August 31, 2016. A total of 13 publications comprising 29 case-control studies were enrolled for three polymorphisms in three miRNAs. Overall analyses suggested significant associations between miR-146a rs2910164 polymorphism and urological neoplasms risk in allelic, homozygote and recessive models. In the stratified analysis by ethnicity, we uncovered a significant association between rs2910164 polymorphism and risk of urological neoplasms in Asian populations in allelic, homozygote and recessive models. Highlighted, when stratified analysis was conducted by cancer type, rs2910164 polymorphism was also significantly associated with an increased risk of bladder cancer in allelic, homozygote and recessive models. Although for rs11614913 and rs3746444 polymorphisms, overall analyses suggested negative results, for rs11614913 polymorphism, when subgroup analysis was conducted by cancer type, a significantly decreased risk of renal cell cancer was identified in recessive model. In brief, current work indicated that miR-146a rs2910164 polymorphism is a risk factor for urological neoplasms, particularly for bladder cancer.

MiR-146a and miR-196a-2 polymorphisms are associated with hepatitis virus-related hepatocellular cancer risk: a meta-analysis

Previous studies have investigated the role of miR-146a rs2910164 and miR-196a-2 rs11614913 polymorphisms in hepatocellular carcinoma (HCC) susceptibility, but the results are contradictory and few specifically studied hepatitis virus-related HCC. Therefore, we conducted a meta-analysis to evaluate the association between these two polymorphisms and hepatitis virus-related HCC risk. We performed a systematical search in EMBASE, PubMed, Web of Science, CNKI and Wanfang databases as of 25th November, 2016. Finally, we assessed 14 studies involving 3852 cases and 5275 controls. Our results suggest that rs2910164 has a significant association with increased hepatitis virus-related HCC risk in allelic, homozygous, heterozygous, and dominant models (CG+GG vs. CC: OR=1.22, 95% CI=1.06-1.39, P=0.004), particularly in Chinese and HBV-related HCC subgroups. Conversely, rs11614913 was associated with lower hepatitis virus-related HCC risk in the overall analysis under allelic (T vs. C: OR=0.85, 95% CI=0.74-0.98, P=0.02), homozygous, dominant and recessive models. Subgroup analyses showed decreased risk in Chinese, HBV- and HCV-related HCC. In conclusion, miR-146a C>G (rs2910164) can increase HBV-related HCC risk while miR-196a-2 C>T (rs11614913) may decrease the risk of HBV- and HCV-related HCC, especially in the Chinese population. Further, large-scale studies including other races are required to confirm these findings.

Functional genetic variants in pre-miR-146a and 196a2 genes are associated with risk of lung cancer in North Indians

Objective: To find the association of two pre-miRNA polymorphisms with risk of lung cancer in North Indians. Materials & methods: Genotyping of 250 cases and 255 controls for miR-146a and miR-196a2 using PCR-RFLP. Results: Heterozygous subjects showed a risk toward lung cancer (LC), especially for adenocarcinoma (OR: 1.82; 95% CI: 1.04–3.20; p = 0.03) in miR-146a gene. TT genotype for miR-196a2 gene also showed 3.2-fold risk toward LC and the risk was fivefold higher for squamous cell carcinoma. Survival rate was significantly lower in subjects with TT genotype as compared with the CC genotype in miR-196a2. Conclusion: Both the single nucleotide polymorphism variants showed a positive association toward risk of lung cancer.

Association between single nucleotide polymorphisms in miRNA196a-2 and miRNA146a and susceptibility to hepatocellular carcinoma in a Chinese population

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers in the world and deeply threatens people's health, especially in China. Techniques of early diagnosis, prevention and prediction are still being discovered, among which the approaches based on single nucleotide polymorphisms in microRNA genes (miRNA SNPs) are newly proposed and show prospective potential. In particular, the association between SNPs in miRNA196a-2 (rs11614913) and miRNA146a (rs2910164) and HCC has been investigated. However, the conclusions made were conflicting, possibly due to insufficient sample size or population stratification. Further confirmations in well-designed large samples are still required. In this study, we verified the association between these two SNPs and the susceptibility to HCC by MassARRAY assay in a 2,000 large Chinese case-control sample. Significant association between rs11614913 and HCC was confirmed. Subjects with the genotype of CT+TT or T allele in rs11614913 were more resistant to HCC (CT+TT: OR (95% CI)=0.73 (0.57-0.92), P=0.01; T allele: OR (95% CI)=0.85 (0.75-0.97), P=0.02) and HBV-related HCC (CT+TT: OR (95% CI)=0.69 (0.53-0.90), P=0.01; T allele: OR (95% CI)=0.82 (0.71-0.95), P=0.01). The affected carriers of CT or TT also tended to have lower levels of serum AFP (P=0.01). This study demonstrated a role of rs11614913 in the etiology of HCC. Further research should focus on the clinical use of this miRNA SNP, so as to facilitate conquering HCC.

Associations between three common MicroRNA polymorphisms and hepatocellular carcinoma risk in Chinese

AIM

Associations between polymorphisms in miR-146aG>C, miR-196a2C>T and miR-499A>G and risk of HCC, and interaction with HBV infection in a Chinese population, were the target of the present research.

METHODS

The duplex polymerase-chain-reaction with confronting-two-pair primers (PCR-RFLP) was performed to determine the genotypes of the miR-146aG>C, miR-196a2C>T and miR-499A>G genotypes. Associations of polymorphisms with the risk of HCC were estimated by conditional logistic regression analysis.

RESULTS

Drinking, family history of cancer, HBsAg and HCV were risk factors for HCC. Multivariate regression analyses showed that subjects carrying the miR-196a2 CC genotype had significantly increased risk of HCC, with an adjusted OR (95% CI) of 2.18 (1.23-3.80). In addition, cases carrying the miR-196a2 C allele had a 1.64-fold increase in the risk for HCC (95%CI=1.03-2.49). The miR-196a CT and TT genotypes greatly significantly increased the risk of HCC in subjects with HBV infection, with adjusted ORs (95% CI) of 2.02 (1.12-3.68) and 2.69 (1.28-5.71), respectively.

CONCLUSION

Our results demonstrate that miR-196a2 CC genotype and C allele have an important role in HCC risk in Chinese, especially in patients with HBV infection.

Association of Pre-miR-146a rs2910164 Polymorphism with Papillary Thyroid Cancer

The incidence rate of papillary thyroid cancer (PTC) has increased over the past decades, but the pathogenesis remains unclear. rs2910164, located in pre-miR-146a, has been studied in PTCs with different ethnicity, but the results were inconsistent. Here we evaluate the association between rs2910164 polymorphism and PTC and investigate the effect of this polymorphism on patients' clinicopathological characteristics. 1238 PTC patients and 1275 controls, all Han population, from Northern China, were included in our study. rs2910164 was genotyped using Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS). Analysis of inheritance model was performed using the SNPStats program. Strength of association was assessed by odds ratio (OR) and 95% confidence interval (CI). Overall, no statistical difference in rs2910164 genotype distribution and allelic frequencies between cases and controls was found, and patients with different genotypes had similar clinicopathological characteristics in terms of stage, location, concurrent of benign thyroid tumor, and thyroiditis, while, as the number of G alleles increased, proportion of patients aged ≥45 years and those without metastasis increased (P trend < 0.001 and P trend = 0.003, resp.). However, no association remained significant after Bonferroni correction under any model of inheritance. Our results suggest no association between rs2910164 polymorphism with PTC and patients' clinicopathological characteristics.

Meta-analysis of Hsa-mir-499 polymorphism (rs3746444) for cancer risk: evidence from 31 case-control studies

BACKGROUND

MicroRNAs (miRNAs) are a family of endogenous, small and non-coding RNAs that regulate gene expression negatively at the post-transcriptional level by suppressing translation or degrading target mRNAs, and are involved in diverse biological and pathological processes. Single nucleotide polymorphisms (SNPs) which are located in the miRNA-coding genes may participate in the process of development and diseases by altering the expression of mature miRNA. Recent studies investigating the association between hsa-mir-499 polymorphism (rs3746444) and cancer risk have yielded conflicting results.

METHODS

In this meta-analysis, we conducted a search of case-control studies on the associations of SNP rs3746444 with susceptibility to cancer in electronic databases. A total of 31 studies involving 12799 cases and 14507 controls were retrieved and the strength of the association was estimated by pooled odds ratios (ORs) and 95% confidence intervals (CIs). Hardy-Weinberg equilibrium (HWE) was assessed by the goodness-of-fit chi-square test in controls. Subgroup analyses were done by racial descent and cancer type. Publication bias of literatures was evaluated by visual inspection of funnel plots and the linear regression asymmetry test by Egger et al. Sensitivity analysis was conducted by excluding one study at a time to examine the influence of individual data set on the pooled ORs.

RESULTS

Overall, significant association between rs3746444 polymorphism and susceptibility to cancer was identified in TC versus TT and TC/CC versus TT (dominant) models. In the stratified analyses, increased risks were found in Asians, but not in Caucasians in all comparison models tested. Moreover, significant association with an increased risk was found in Chinese population. Also, much higher significant association with increased cancer risks were found in Iranian population. In different cancer types, a decreased risk was found in esophageal cancer.

CONCLUSION

Our meta-analysis suggested that hsa-mir-499 rs3746444 T > C polymorphism is associated with the risk of cancer in Asians, mainly in Iranian and Chinese population. However, rs3746444 T > C polymorphism is negatively associated with the risk of esophageal cancer.

High-resolution melting analysis reveals genetic polymorphisms in microRNAs confer hepatocellular carcinoma risk in Chinese patients

BACKGROUND

Although several single-nucleotide polymorphisms in microRNA (miRNA) genes have been associated with primary hepatocellular carcinoma, published findings regarding this relationship are inconsistent and inconclusive.

METHODS

The high-resolution melting (HRM) analysis was used to determine whether the occurrence of the SNPs of miR-146a C > G (rs2910164), miR-196a2 C > T (rs11614913), miR-301b A > G (rs384262), and miR-499 C > T (rs3746444) differs in frequency-matched 314 HCC patients and 407 controls by age and sex.

RESULTS

The groups' genotype distributions of miR-196a2 C > T and miR-499 C > T differed significantly (P < 0.01), both of them increased the risk of HCC in different dominant genetic models (P < 0.01); compared with individuals carrying one or neither of the unfavorable genotypes, individuals carrying both unfavorable genotypes (CT + CC) had a 3.11-fold higher HCC risk (95% confidence interval (CI), 1.89-5.09; P = 7.18 × 10-6). Moreover, the allele frequency of miR-499 C > T was significantly different between the two groups, and the HCC risk of carriers of the C allele was higher than that of carriers of the T allele (odds ratio, 1.53; 95% CI, 1.15-2.03; P = 0.003). Further, we found that the activated partial thromboplastin time (APTT) in HCC patients with miR-196a2 CC genotype was longer than patients with TT genotypes (P < 0.05), and HCC patients with miR-499 C allele had higher serum levels of direct bilirubin, globulin, γ-glutamyltranspeptidase, alkaline phosphatase, and lower serum cholinesterase (P < 0.05).

CONCLUSIONS

Our findings suggest that the SNPs in miR-196a2 C > T and miR-499 C > T confer HCC risk and that affect the clinical laboratory characteristics of HCC patients.

Association between four common microRNA polymorphisms and the risk of hepatocellular carcinoma and HBV infection

microRNAs (miR/miRNAs) have been demonstrated to function as tumor suppressors and oncogenes, and miRNA polymorphisms may have a role in cancer development. The present study aimed to investigate the association between the miR-146aG>C, miR-149C>T, miR-196a2C>T and miR-499A>G polymorphisms and the risk of hepatocellular carcinoma (HCC) and hepatitis B virus (HBV) infection. A total of 271 patients with HCC and 532 healthy control participants were enrolled in the present study. miR-146aG>C, miR-149C>T, miR-196a2C>T and miR-499A>G polymorphisms were genotyped using the polymerase chain reaction-restriction fragment length polymorphism method. A significant difference was identified in the genotype frequency of miR-196a2C>T in the patients in the case group compared with the control group (χ²=6.88; P=0.032). Compared with the CC genotype, the miR-196a2 TT genotype was associated with a significantly reduced risk of HCC [odds ratio (OR), 0.62; 95% confidence interval (CI), 0.38–0.99], and a significantly reduced risk was also found in the dominant (OR, 0.69; 95% CI, 0.49–0.98) and recessive (OR, 0.70; 95% CI, 0.46–1.02) models. Moreover, individuals with HBV who were carrying the miR-196a2 CT and TT genotypes had a significantly reduced risk of HCC (OR, 0.62; 95% CI, 0.41–0.95; and OR, 0.39; 95% CI, 0.20–0.73, respectively). In conclusion, the present study found that the miR-196a2C>T polymorphism has a protective effect in patients with HCC, particularly in those with HBV infection.

Association between miR-146aG>C and miR-196a2C>T polymorphisms and the risk of hepatocellular carcinoma in a Chinese population

MicroRNAs have been demonstrated to have a role in susceptibility and prognosis of various types of human cancer. We investigated the association between polymorphisms in miR-146aG>C, miR-196a2C>T, and miR-499A>G and hepatocellular carcinoma (HCC) risk and interaction with HCC and hepatitis B virus (HBV) infection. Two hundred sixty-six cases with HCC and 281 health controls were enrolled in the present study. Genotyping of the miR-146aG>C, miR-196a2C>T, and miR-499A>G genotypes was conducted by duplex polymerase chain reaction with the confronting two-pair primer (PCR-RFLP). Subjects with miR-146a GG and G allele had an increased risk of HCC compared with the homozygote CC genotype. Similarly, HCC patients carrying microRNA (miRNA)-196a2 computed tomography, TT, and T allele significantly decreased the risk of HCC relative to the CC genotype. Stratified analysis indicated that miR-196a2C>T polymorphism was associated with reduced risk of HBV-related HCC, but not in hepatitis C virus- and nonviral-related HCC cases. In conclusion, miR-146aG>C and miR-196a2C>T polymorphism are associated with risk of HCC patients in China, especially in patients with HBV infection. SNPs in miRNA sequences can be used as a diagnostic biomarker for HCC.

Association between rs2910164, a single nucleotide polymorphism in miRNA-146a, and susceptibility to hepatocellular carcinoma: A Meta-analysis

AIM: To accurately evaluate the association between the miRNA-146a rs2910164 polymorphism and susceptibility to hepatocellular carcinoma by Meta-analysis.

METHODS: An electronic search of PubMed, Excerpta Medica Database (Embase), Chinese Biomedical Literature Database (CBM), the Cochrane Library, Weipu and Wanfang database for relevant articles was conducted. The difference of miRNA-146a rs2910164 genotypes (G vs C, GG vs CC, GG vs GC, GC vs CC, GG + GC vs CC, and GG vs GC + CC) between cases and controls was analyzed through Meta-analysis.

RESULTS: A total of 8 studies involving 5968 subjects were found to be eligible for our meta-analysis. There was evidence of association between miR-146a rs2910164 polymorphism and the risk of hepatocellular carcinoma in the overall analysis (GC vs CC: OR = 1.15; 95%CI: 1.02-1.92, P = 0.02; GG + GC vs CC: OR = 1.15; 95%CI: 1.03-1.29, P = 0.01). In the subgroup analysis by ethnicity, similar results could be found among Asians (GC vs CC: OR = 1.15, 95%CI = 1.02-1.29, P = 0.02).

CONCLUSION: Our Meta-analysis suggested that the rs2910164 polymorphism in miR-146a was more likely to be associated with hepatocellular carcinoma risk. Besides, the CC genotype of rs2910164 might be associated with a reduced risk for hepatocellular carcinoma.

Association between two common polymorphisms and risk of hepatocellular carcinoma: evidence from an updated meta-analysis

Background. Recent studies suggested that two common polymorphisms, miR-146a G>C and miR-196a2 C>T, may be associated with individual susceptibility to hepatocellular carcinoma (HCC). However, the results remain conflicting rather than conclusive. Object. The aim of this study was to assess the association between miR-146a G>C and miR-196a2 C>T polymorphisms and the risk of HCC. Methods. A meta-analysis of 17 studies (10938 cases and 11967 controls) was performed. Odds ratios and 95% confidence intervals were used to evaluate the strength of the association. Results. For miR-146a G>C, the variant genotypes were associated with a decreased risk of HCC (CC versus GG: OR = 0.780 and 95% CI 0.700–0.869; GC/CC versus GG: OR = 0.865 and 95% CI 0.787–0.952; CC versus GC/GG: OR = 0.835 and 95% CI 0.774–0.901). For miR-196a2 C>T, significant association was also observed (TT versus CC: OR = 0.783, 95% CI: 0.649–0.943, and P = 0.010; CT versus CC: OR = 0.831, 95% CI 0.714–0.967, and P = 0.017; CT/TT versus CC: OR = 0.817, 95% CI 0.703–0.949, and P = 0.008). Conclusion. The two common polymorphisms miR-146a G>C and miR-196a2 C>T were associated with decreased HCC susceptibility, especially in Asian population.

Expression and clinicopathological significance of miR-146a in hepatocellular carcinoma tissues

BACKGROUND

Aberrant expression of microRNA-146a (miR-146a) has been found in several classes of cancers. However, its expression and clinicopathological contribution in hepatocellular carcinoma (HCC) has not been fully elucidated.

OBJECTIVE

To explore the clinicopathological significance of the miR-146a level in HCC formalin-fixed paraffin-embedded (FFPE) tissue.

METHODS

Eighty-five HCC samples and their para-cancerous normal liver tissues were collected. Total mRNA including miRNA was extracted, and miR-146a expression was determined using real-time RT-PCR. Furthermore, the correlation between the miR-146a expression and clinicopathological parameters was investigated.

RESULTS

MicroRNA-146a expression in HCC tissues was lower compared with that in adjacent non-cancerous hepatic tissues. MicroRNA-146a expression was also related to clinical TNM stage, metastasis, portal vein tumor embolus, and number of tumor nodes.

CONCLUSIONS

Down-regulation of miR-146a is related to HCC carcinogenesis and deterioration of HCC. MicroRNA-146a may act as a suppressor miRNA of HCC, and it is therefore a potential prognostic biomarker for HCC patients.

Association between microRNA polymorphisms and cancer risk based on the findings of 66 case-control studies

MicroRNAs (miRNAs) are small non-coding RNA molecules, which participate in diverse biological processes and may regulate tumor suppressor genes or oncogenes. Single nucleotide polymorphisms (SNPs) in miRNA may contribute to diverse functional consequences, including cancer development, by altering miRNA expression. Numerous studies have shown the association between miRNA SNPs and cancer risk; however, the results are generally debatable and inconclusive, mainly due to limited statistical power. To assess the relationship between the five most common SNPs (miR-146a rs2910164, miR-196a2 rs11614913, miR-499 rs3746444, miR-149 rs2292832, and miR-27a rs895919) and the risk cancer development, we performed a meta-analysis of 66 published case-control studies. Crude odds ratios at 95% confidence intervals were used to investigate the strength of the association. No association was observed between rs2910164 and cancer risk in the overall group. However, in stratified analysis, we found that either the rs2910164 C allele or the CC genotype was protective against bladder cancer, prostate cancer, cervical cancer, and colorectal cancer, whereas it was a risk factor for papillary thyroid carcinoma and squamous cell carcinoma of the head and neck (SCCHN). Further, rs11614913 was found to be significantly associated with decreased cancer risk, in particular, for bladder cancer, gastric cancer, and SCCHN. For miR-499, a significant association was found between the rs3746444 polymorphism and cancer risk in pooled analysis. In subgroup analysis, similar results were mainly observed for breast cancer. Finally, no association was found between rs2292832 and rs895919 polymorphisms and cancer risk in the overall group and in stratified analysis. In summary, miR-196a2 rs11614913, miR-146a rs2910164, and miR-499 rs3746444 are risk factors for cancer development, whereas mir-149 rs2292832 and miR-27a rs895919 are not associated with cancer risk.