Systematic evaluation of cancer risk associated with rs2292832 in miR‑149 and rs895819 in miR‑27a: a comprehensive and updated meta‑analysis

Genetic Variation in miR-27a Is Associated with Fluoropyrimidine-Associated Toxicity in Patients with Dihydropyrimidine Dehydrogenase Variants after Genotype-Guided Dose Reduction

Dihydropyrimidine dehydrogenase (DPYD) is the rate-limiting enzyme involved in the metabolism of fluoropyrimidine-based chemotherapy. However, single-nucleotide variants (SNVs) in DPYD only partially explain fluoropyrimidine-induced toxicity. The expression of DPYD has previously been shown to be regulated by microRNA-27a (miR-27a) and a common miR-27a SNV (rs895819) has been associated with an increased risk of toxicity in patients harboring a DPYD variant who received standard fluoropyrimidine dosing. We investigated if the miR-27a rs895819 SNV was associated with toxicity in DPYD wildtype patients and carriers of DPYD variants who received a reduced dose. The regulation of DPYD using miR-27a was investigated in HepG2 cells utilizing a miR-27a mimic. miR-27a overexpression decreased DPYD mRNA expression compared to control cells (p < 0.0001). In a cohort of patients that received pre-emptive DPYD genotyping, 45 patients had a DPYD variant and 180 were wildtype. Patients heterozygous for rs895819 had an increased risk of toxicity, which was seen in both patients who were wildtype for DPYD variants (OR (95%CI) = 1.99 (1.00-3.99)) and DPYD variant carriers (OR (95%CI) = 8.10 (1.16-86.21)). Therefore, miR-27a rs895819 may be a clinically relevant predictor of fluoropyrimidine-associated toxicities. Furthermore, toxicity was more profound in DPYD variant carriers, even after DPYD genotype-guided dose reduction. This suggests that patients may benefit from miR-27a genotyping to guide fluoropyrimidine dosing.

Association of miR-149 T>C and miR-196a2 C>T Polymorphisms with Colorectal Cancer Susceptibility: A Case-Control Study

The principal aim of the current study was to investigate the relationship between miR-149 T>C (rs2292832) and miR-196a2 C>T (rs11614913) small non-coding RNA polymorphisms and the risk of developing CRC in the Azerbaijani population. The study included 120 patients diagnosed with CRC and 125 healthy individuals. Peripheral blood samples were collected from all the subjects in EDTA tubes and DNA extraction was performed by salting out. Polymorphisms were determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. While comparing without gender distinction no statistical correlation was found between the heterozygous TC (OR = 0.66; 95% CI = 0.37-1.15; p = 0.142), mutant CC (OR = 1.23; 95% CI = 0.62-2.45; p = 0.550), and mutant C (OR = 1.03; 95% CI = 0.72-1.49; p = 0.859) alleles of the miR-149 gene and the CT (OR = 1.23; 95% CI = 0.69-2.20; p = 0.485), mutant TT (OR = 1.29; 95% CI = 0.67-2.47; p = 0.452), and mutant T (OR = 1.17; 95% CI = 0.82-1.67; p = 0.388) alleles of the miR-196a2 gene and the risk of CRC. However, among women, miR-149 TC (OR = 0.43; 95% CI = 0.19-1.01; p = 0.048) correlated with a reduced risk of CRC, whereas miR-196a2 CT (OR = 2.77; 95% CI = 1.13-6.79; p = 0.025) correlated with an increased risk of CRC. Our findings indicated that miR-149 T>C (rs2292832) might play a protective role in the development of CRC in female patients, whereas the miR-196a2 (rs11614913) polymorphism is associated with an increased risk of CRC in women in the Azerbaijani population, highlighting the importance of gender dimorphism in cancer etiology.

Influence of Genetic Variations in miRNA and Genes Encoding Proteins in the miRNA Synthesis Complex on Toxicity of the Treatment of Pediatric B-Cell ALL in the Brazilian Amazon

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer in the world. Single nucleotide variants (SNVs) in miRNA and genes encoding proteins of the miRNA synthesis complex (SC) may affect the processing of drugs used in the treatment of ALL, resulting in treatment-related toxicities (TRTs). We investigated the role of 25 SNVs in microRNA genes and genes encoding proteins of the miRNA SC, in 77 patients treated for ALL-B from the Brazilian Amazon. The 25 SNVs were investigated using the TaqMan^® OpenArray™ Genotyping System. SNVs rs2292832 (MIR149), rs2043556 (MIR605), and rs10505168 (MIR2053) were associated with an increased risk of developing Neurological Toxicity, while rs2505901 (MIR938) was associated with protection from this toxicity. MIR2053 (rs10505168) and MIR323B (rs56103835) were associated with protection from gastrointestinal toxicity, while DROSHA (rs639174) increased the risk of development. The rs2043556 (MIR605) variant was related to protection from infectious toxicity. SNVs rs12904 (MIR200C), rs3746444 (MIR499A), and rs10739971 (MIRLET7A1) were associated with a lower risk for severe hematologic toxicity during ALL treatment. These findings reveal the potential for the use of these genetic variants to understand the development of toxicities related to the treatment of ALL in patients from the Brazilian Amazon region.

The association between genetic variation rs2292832 and the processing efficiency of pre-mir-149 affects the risk of breast cancer

BACKGROUND

microRNAs (miRNAs) play key roles in regulating cancer development, including breast cancer. Variation in miRNA genes can associate with the risk of cancer by alterations in the miRNA's processing and maturation. Therefore, human blood samples and breast cancer cell line (MCF7) were analyzed to study any possible association between the genetic variant (rs2292832) in the miR-149 precursor and breast cancer susceptibility.

METHODS

To study the role of rs2292832 polymorphism in breast cancer, the miR-149 gene variant was genotyped using PCR-RFLP. For evaluating the effect of SNP on function and expression levels of mature miR-149, we inserted pre-miR-149 and flanking region with CC or TT genotype into a pEGFPN1 expression vector, and qPCR was accomplished. Cell survival, proliferation, and migration properties investigated by MTT and wound healing assay. Statistical analysis was carried out for data analysis.

RESULTS

T allele in variant rs2292832 is associated with an increased risk of breast cancer. Such association was also obtained in co-dominant (OR = 2.5) and dominant (OR = 2.016) models. The variant allele led to reduced production of mature miR-149 and resulted in increased cell proliferation and migration of MCF7 cells.

CONCLUSION

These findings suggest that miR-149 suppresses tumor cell proliferation, and the pre-mir-149 polymorphism affects the processing of miR-149, causing an alteration in the abundance of the miRNA mature form, which can regulate tumor progression and metastasis.

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.

Characteristics of miRNA-SNPs in healthy Japanese subjects and non-small cell lung cancer, colorectal cancer, and soft tissue sarcoma patients

Single nucleotide polymorphisms in genes encoding microRNAs (miRNA-SNPs) may affect the maturation steps of miRNAs or target mRNA recognition, leading to changes in the expression of target mRNAs to cause gain- or loss-of-function changes. Several miRNA-SNPs are known to be associated with the risk of diseases such as cancer. The purpose of this study was to comprehensively determine the miRNA-SNPs in Japanese individuals to evaluate the differences in allele frequencies between ethnicities by comparing data from the global population in the 1000 Genomes Project and differences between healthy subjects and cancer patients. We performed next-generation sequencing targeting genes encoding 1809 pre-miRNAs. As a result, 403 miRNA-SNPs (146 miRNA-SNPs per subject on average) were identified in 28 healthy Japanese subjects. We observed significant differences in the allele frequencies between ethnicities in 33 of the 403 miRNA-SNPs. The numbers of miRNA-SNPs per subject in 44 non-small cell lung cancer (NSCLC), 33 colorectal cancer (CRC), and 15 soft tissue sarcoma (STS) patients were almost equal to those in healthy subjects. Significant differences in allele frequencies were observed for 14, 11, and 9 miRNA-SNPs in NSCLC, CRC, and STS patients compared with the frequencies in healthy subjects, suggesting that these SNPs can be biomarkers of risk for each type of cancer assessed. In summary, we comprehensively characterized miRNA-SNPs in Japanese individuals and found differences in allele frequencies of several miRNA-SNPs between ethnicities and between healthy subjects and cancer patients. Studies investigating a larger number of subjects should be performed to confirm the potential of miRNA-SNPs as biomarkers of cancer risk.

Role of miRNA gene variants in the susceptibility and pharmacogenetics of colorectal cancer

Colorectal cancer (CRC) is one of the most significant challenges in the field of cancer pathology. miRNAs are among the genetic factors associated with the disease. Although many studies have reviewed the expression patterns of various miRNAs in CRC, few studies have focused on different variants of miRNA. In the present review, miRNA variants have been categorized into three subgroups, including miRNA variants that predict susceptibility to CRC, miRNA variants that predict the clinical parameters of CRC and finally, miRNA variants that predict the pharmacological aspects of CRC. Moreover, a comprehensive review of potentially functional miRNA-associated SNPs as well as their importance as candidate cancer biomarkers are discussed.

Genetic variants in microRNAs are associated with cervical cancer risk

Because genetic variants in microRNAs (miRNAs) or their surrounding regions can alter miRNA processing, expression and final biological function, we investigated whether miRNA single-nucleotide polymorphisms (SNPs) are associated with cervical cancer (CC) susceptibility. Common miRNA SNPs (i.e. miR-146a rs2910164, miR-149 rs2292832, miR-196a2 rs11614913, miR-499 rs3746444, miR-605 rs2043556 and miR-618 rs2682818) were genotyped in the 954 patients and 1339 controls. The results showed that the miR-149 rs2292832 TC/CC genotypes were associated with a 21% increased risk of CC compared with the TT genotype [odds ratio (OR) = 1.21, 95% confidence interval (CI) = 1.00-1.47]. The association was more prominent among the subjects with age ≤ 48 years (OR = 1.55, 95% CI = 1.16-2.06), having history of abortion (OR = 1.44, 95% CI = 1.12-1.86), premenopausal status (OR = 1.41, 95% CI = 1.08-1.85) and patients with clinical stage II of CC (OR = 1.43, 95% CI = 1.08-1.90). The expression plasmids containing the pre-miR-149 sequence with C allele of rs2292832 transcribed higher amount of mature miR-149-5p/3p than these with T allele in the HeLa and SiHa cells. Therefore, the rs2292832 polymorphism might influence CC susceptibility through modulation of the procession of pre-miR-149 to mature miRNAs.

Single nucleotide alterations in MicroRNAs and human cancer-A not fully explored field

MicroRNAs are ~20 nt long small noncoding RNAs that are processed from stem-looped precursors and function mainly as posttranscriptional regulators of protein coding genes through binding to 3'-untranslated regions of messenger RNAs to inhibit the translation or cause RNA degradation. It is predicted microRNAs could regulate up to half of all human genes and are proved to play important roles in human diseases including cancer. They bind to target mRNAs based on complementary binding which is dominated by the so-called "seed" region which are the 5' 2-8 bases of the microRNA. Due to the small size in nature, even a single nucleotide variation in the precursor region especially those located in the seed regions could show big influence. Here, I summarized and reviewed the current knowledge of these single nucleotide alterations in microRNAs in human cancer including (i) common SNPs in the precursor region, (ii) isomiRs, (iii) somatic mutations of microRNAs. Briefly, this is an underexploited field and clearly, warrants further studies to reveal their biological and clinical significances. I believe they will be key to advancing personalized medicine.

rs895819 in microRNA-27a increase stomach neoplasms risk in China: A meta-analysis

BACKGROUND

Across the globe, gastric cancer is a significant public health problem. This meta-analysis was conducted to investigate the association of microRNA-27a (miRNA-27a) rs895819 with gastric cancer risk.

METHODS

The search of databases updated on October 10, 2018 included Pubmed, Embase, Cochrane Library and Web of science. Odds ratio (ORs) and 95% confidence interval (CIs) were calculated to assess the risk of tumor.

RESULTS

Overall meta-analysis suggested the miRNA-27a rs895819 was not related to the gastric carcinogenesis among all model including allele contrast (G vs A, pooled OR: 1.096, 95% CI: 0.962-1.249, P = 0.196), codominant model (GG vs AA, pooled OR: 1.124, 95% CI: 0.794-1.592, P = 0.590; AG vs AA, pooled OR: 1.101, 95% CI: 0.966-1.217, P = 0.060), dominant model (AG + GG vs AA, pooled OR: 1.123, 95% CI: 0.964-1.307, P = 0.136) and recessive model (GG vs AG + AA, pooled OR: 0.927, 95% CI: 0.673-1.278, P = 0.644). Interestingly, among different ethnicity group, significant relation between rs895819 and gastric cancer was observed in co-dominant model among Chinese population (AG vs AA, pooled OR: 1.158, 95% CI: 1.038-1.291, P = 0.008) but not some regions of European population (AG vs AA, pooled OR: 0.852, 95% CI: 0.632-1.148, P = 0.179).

CONCLUSIONS

Our results find that rs895819 contributed to occurrence of gastric cancer in co-dominant model in Chinese population.

Breast Cancer and miR-SNPs: The Importance of miR Germ-Line Genetics

Recent studies in cancer diagnostics have identified microRNAs (miRNAs) as promising cancer biomarkers. Single nucleotide polymorphisms (SNPs) in miRNA binding sites, seed regions, and coding sequences can help predict breast cancer risk, aggressiveness, response to stimuli, and prognosis. This review also documents significant known miR-SNPs in miRNA biogenesis genes and their effects on gene regulation in breast cancer, taking into account the genetic background and ethnicity of the sampled populations. When applicable, miR-SNPs are evaluated in the context of other patient factors, including mutations, hormonal status, and demographics. Given the power of miR-SNPs to predict patient cancer risk, prognosis, and outcomes, further study of miR-SNPs is warranted to improve efforts towards personalized medicine.

Association of mir-196a-2 rs11614913 and mir-149 rs2292832 Polymorphisms With Risk of Cancer: An Updated Meta-Analysis

Background: Accumulating evidence suggests that functional dysregulations of miRNAs, especially miR-196a-2 and miR-149, in cancers could be attributed to polymorphisms in miRNA sequences. This study was aimed at clarifying the association of mir-196a-2 rs11614913 and mir-149 rs2292832 with cancer risk by performing an updated meta-analysis of genetic association studies.

Methods: PubMed, Embase, Scopus, and ScienceDirect databases were searched until 9 April 2018 to identify eligible studies. Studies should meet the following criteria to be included in the meta-analysis: evaluation of genetic association between rs11614913 and/or rs2292832 and susceptibility to cancer; A case-control design; Written in English; Availability of sufficient data for estimating odds ratio (OR) and its 95% confidence interval (95%CI). Studies that met the following criteria were excluded: review articles, meta-analysis, abstracts or conference papers; duplicate publications; studies on animals or cell-lines; studies without a case-control design; studies that did not report genotype frequencies. Pooled ORs and 95% CIs were estimated using a total of 111 studies (41,673 cases and 49,570 controls) for mir-196a rs11614913 and 44 studies (15,954 cases and 19,594 controls) for mir-149 rs2292832. Stratified analysis according to quality scores, genotyping method, ethnicity, broad cancer category and cancer type was also performed.

Results: Mir-196a-2 rs11614913 T allele was associated with decreased cancer risk in overall population. The association was only significant in Asians but not Caucasians. In subgroup analysis, significant associations were found in high quality studies, gynecological cancers, ovarian, breast, and hepatocellular cancer. Mir-149 rs2292832 was not associated with cancer risk in overall population and there were no differences between Asians and Caucasians. However, the T allele was associated with a decrease risk of gastrointestinal tract cancers under the heterozygote model and an increased risk of colorectal cancer under the recessive model.

Conclusions: The present meta-analysis suggests that mir-196a-2 rs11614913 may contribute to the risk of cancer especially in Asians. Mir-149 rs2292832 may modulate the risk of gastrointestinal tract cancers especially colorectal cancer. This study had some limitations such as significant heterogeneity in most contrasts, limited number of studies enrolling Africans or Caucasians ancestry and lack of adjustment for covariates and environmental interactions.

Functional polymorphism within miR-23a∼27a∼24-2 cluster confers clinical outcome of breast cancer in Pakistani cohort

AIM

MicroRNAs (miRNAs) are small regulatory RNA molecules that control gene activity by base pairing with target messenger RNA leading to their cleavage or translational repression. Previous studies show an involvement of miRNAs in various diseases including cancer. Members of the Mir-23a cluster (MIR23A, MIR24-2 and MIR27A) are involved in breast cancer (BC).

METHODS

In the present study, miR-23a/24-2/27a cluster was screened for genetic mutation in BC patients.

RESULTS

Heterozygous (A/G allele) as well as homozygous (G/G allele) variants were found in mir-27a gene in screened BC patients. RNA structural analysis revealed that the single nucleotide polymorphism (SNP) effects the size of the terminal loop in the precursor miRNA (pre-miRNA).

CONCLUSION

The altered (G allele) hairpin structure observed was two bases longer than the reference (A allele) hairpin.

miR-149-5p inhibits cell growth by regulating TWEAK/Fn14/PI3K/AKT pathway and predicts favorable survival in human osteosarcoma

MicroRNAs (miRNAs) as small non-coding RNAs act as either tumor suppressors or oncogenes in human cancers, of which miR-149-5p (miR-149) is involved in tumor growth and metastasis, but its role and molecular mechanisms underlying osteosarcoma growth are poorly understood. The correlation of miR-149 expression with clinicopathological characteristics and prognosis in patients with sarcoma was analyzed by The Cancer Genome Atlas (TCGA) RNA-sequencing data. Osteosarcoma cell growth affected by miR-149 was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays. As a result, we found that the expression level of miR-149 was markedly downregulated in human sarcoma samples and were negatively associated with tumor size, acting as an independent prognostic factor for overall survival of the sarcoma patients. Restoration of miR-149 expression suppressed osteosarcoma cell growth, while its knockdown reversed these effects. Furthermore, we identified TNFRSF12A (TNF receptor superfamily member 12A), also called fibroblast growth factor–inducible 14 (Fn14) as a direct target of miR-149, and TNFRSF12A and its ligand TNFSF12 (TNF superfamily member 12), also called tumor necrosis factor–related weak inducer of apoptosis (TWEAK), were both negatively correlated with miR-149 expression in sarcoma samples. Knockdown of TNFRSF12A suppressed cell growth, but its overexpression weakened the antiproliferative effects of miR-149 via the PI3K/AKT (AKT serine/threonine kinase) signaling pathway. Altogether, our findings show that miR-149 functions as a tumor suppressor in osteosarcoma via inhibition of the TWEAK–Fn14 axis and represents a potential therapeutic target in patients with osteosarcoma.

MicroRNA and Human Bone Health

The small non‐coding microRNAs (miRNAs) are post‐transcription regulators that modulate diverse cellular process in bone cells. Because optimal miRNA targeting is essential for their function, single‐nucleotide polymorphisms (SNPs) within or proximal to the loci of miRNA (miR‐SNPs) or mRNA (PolymiRTS) could potentially disrupt the miRNA‐mRNA interaction, leading to changes in bone metabolism and osteoporosis. Recent human studies of skeletal traits using miRNA profiling, genomewide association studies, and functional studies started to decipher the complex miRNA regulatory network. These studies have indicated that miRNAs may be a promising bone marker. This review focuses on human miRNA studies on bone traits and discusses how genetic variants affect bone metabolic pathways. Major ex vivo investigations using human samples supported with animal and in vitro models have shed light on the mechanistic role of miRNAs. Furthermore, studying the miRNAs’ signatures in secondary osteoporosis and osteoporotic medications such as teriparatide (TPTD) and denosumab (DMab) have provided valuable insight into clinical management of the disease. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research

Association of two microRNA polymorphisms miR-27 rs895819 and miR-423 rs6505162 with the risk of cancer

Many studies have been conducted to investigate the association between miR-27 rs895819 A > G and miR-423 rs6505162 C > A and cancer risk; however, the results are not consistent. In order to acquire a more precise assessment of the correlation, we performed this meta-analysis. We searched PubMed, EMBASE and Web of Science databases to identify eligible studies. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were applied to evaluate the correlation of these two microRNA polymorphisms with cancer risk. Forty-five eligible studies from thirty-five articles were included in our analysis. The results showed that rs895819 was associated with a decreased cancer risk in Caucasians (AG vs. AA: OR = 0.87, 95% CI = 0.79-0.96; GG+AG vs. AA: OR = 0.89, 95% CI = 0.81-0.98). When grouped by ethnicity, an increased risk was observed in colorectal cancer (G vs. A: OR = 1.19, 95% CI = 1.08-1.32; GG vs. AA: OR = 1.58, 95% CI = 1.28-1.96; GG vs. AG+AA: OR = 1.58, 95% CI = 1.29-1.93), while a decreased risk was found in breast cancer (G vs. A: OR = 0.93, 95% CI = 0.87-0.99; GG+AG vs. AA: OR = 0.91, 95% CI = 0.83-0.99). For rs6505162, a significantly decreased cancer risk was observed in lung cancer under all five genetic models. To summarize, our results indicated that rs895819 was a protective factor for cancer in Caucasians and could increase colorectal cancer risk but decrease breast cancer risk. Moreover, rs6505162 was a protective factor for lung cancer.

Quantitative assessment of CD44 genetic variants and cancer susceptibility in Asians: a meta-analysis

CD44 is a well-established cancer stem cell marker playing a crucial role in tumor metastasis, recurrence and chemo-resistance. Genetic variants of CD44 have been shown to be associated with susceptibility to various cancers; however, the results are confounding. Hence, we performed a meta-analysis to clarify these associations more accurately. Overall, rs13347 (T vs. C: OR=1.30, p=<0.004, p_corr=0.032; CT vs. CC: OR=1.29, p=0.015, p_corr=0.047; TT vs. CC: OR=1.77, p=<0.000, p_corr=0.018; CT+TT vs. CC: OR=1.34, p=<0.009, p_corr=0.041) and rs187115 (GG vs. AA: OR=2.34, p=<0.000, p_corr=0.025; AG vs. AA: OR=1.59, p=<0.000, p_corr=0.038; G vs. A allele OR=1.56, p=0.000, p_corr=0.05; AG+GG vs. AA: OR=1.63, p=<0.000, p_corr=0.013) polymorphisms were found to significantly increase the cancer risk in Asians. On the other hand, rs11821102 was found to confer low risk (A vs. G: OR=0.87, p=<0.027, p_corr=0.04; AG vs. GG: OR=0.85, p=<0.017, p_corr=0.01; AG+AA vs. GG: OR=0.86, p=<0.020, p_corr=0.02). Based on our analysis, we suggest significant role of CD44 variants (rs13347, rs187115 and rs11821102) in modulating individual's cancer susceptibility in Asians. Therefore, these variants may be used as predictive genetic biomarkers for cancer predisposition in Asian populations. However, more comprehensive studies involving other cancers and/or populations, haplotypes, gene-gene and gene-environment interactions are necessary to delineate the role of these variants in conferring cancer risk.

miR-149 in Human Cancer: A Systemic Review

MicroRNAs (miRNAs) are small noncoding RNAs that regulate post-transcriptional gene expression via binding to the 3'-untranslated region (3'-UTR) of targeted mRNAs. They are reported to play important roles in tumorigenesis and progression of various cancers. Among them, miR-149 was confirmed to be aberrantly regulated in various tumors. In this review, we provide a complex overview of miR-149, particularly summarize the critical roles of it in cancers and expect to lay the foundation for future works on this important microRNA.

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.

Association between Polymorphisms in MicroRNAs and Risk of Urological Cancer: A Meta-Analysis Based on 17,019 Subjects

Accumulating evidence has demonstrated that some single nucleotide polymorphisms (SNPs) existing in miRNAs correlate with the susceptibility to urological cancers. However, a clear consensus still not reached due to the limited statistical power in individual study. Thus, we concluded a meta-analysis to systematically evaluate the association between microRNA SNPs and urological cancer risk. Eligible studies were collected from PubMed, Embase, Web of Science, and CNKI databases. Pooled odds ratio (OR) and corresponding 95% confidence interval (95% CI) were calculated to assess the strength of the relationships between three SNPs (miR-196a2, C>T rs11614913; miR-146a, G>C rs2910164; and miR-499, A>G rs3746444) and the risk of urological cancers. In addition, the stability of our analysis was evaluated by publication bias, sensitivity and heterogeneity analysis. Overall, a total of 17,019 subjects from 14 studies were included in this meta-analysis. We found that CT (miR-196a2, C>T rs11614913) was a risk factor for renal cell carcinoma (CT vs. CC: OR = 1.72, 95%CI = 1.05-2.80, P = 0.03, I² = 66%), especially in Asian population (CT vs. CC: OR = 1.17, 95%CI = 1.04-1.32, P < 0.01, I² = 0%). miR-146a G>C rs2910164 was a protective factor of urological cancers (C vs. G: OR = 0.87, 95%CI = 0.81-0.93, P < 0.01, I² = 0%), especially for bladder cancer. miR-499 A>G rs3746444 was correlated with an increased risk of urological cancers, specifically in Asian population. In conclusion, our meta-analysis suggests that polymorphisms in microRNAs, miR-196a2, C>T rs11614913, miR-146a G>C rs2910164 and miR-499 A>G rs3746444, may be associated with the development of urological cancers and the risks mainly exist in Asian populations.

Distinct effects of rs895819 on risk of different cancers: an update meta-analysis

Previous studies have indicated an association between the genetic variant in pre-miR-27a rs895819 with A->G transition and cancer risk; however, the results remain inconsistent and somehow conflicting in different cancers. Therefore, to obtain a more reliable conclusion, we performed an update meta-analysis by searching PubMed database or other databases. Odds ratio (ORs) and 95% confidence interval (CIs) were calculated to evaluate cancer risk. A total of 34 case-control studies involving 15,388 cases and 18,704 controls were included. The results showed that rs895819 was associated with an increased cancer risk (GG vs. AA/AG: OR = 1.15, 95% CI = 1.02-1.29). Furthermore, stratification analyses revealed an association of rs895819 with increased cancer risk among Asians (GG vs. AA: OR = 1.17, 95% CI = 1.01-1.36; GG vs. AA/AG: OR = 1.18, 95% CI = 1.03-1.35), but not Caucasians. Interestingly, the [G] allele of rs895819 was significantly associated with decreased risk of breast cancer (G vs. A: OR = 0.91, 95% CI = 0.86-0.97). However, rs895819 was associated with increased risk of colorectal cancer (GG vs. AA: OR = 1.56, 95% CI = 1.31-1.85; GG vs. AA/AG: OR = 1.53, 95% CI = 1.30-1.79; G vs. A: OR = 1.19, 95% CI = 1.09-1.30) and lung cancer (GG vs. AA/AG: OR = 1.43, 95% CI = 1.00-2.04). In addition, no association was found between rs895819 and risk of gastric cancer or esophageal cancer. In conclusion, our findings suggest distinct effects of rs895819 on risk of different cancers, and future well-designed studies with large samples are required to further validate our results.