Single Nucleotide Polymorphisms In miRNA Binding Sites Research Articles

Comprehensive Characterization of the Coding and Non-Coding Single Nucleotide Polymorphisms in the Tumor Protein p63 (TP63) Gene Using In Silico Tools.

Single nucleotide polymorphisms (SNPs) help to understand the phenotypic variations in humans. Genome-wide association studies (GWAS) have identified SNPs located in the tumor protein 63 (TP63) locus to be associated with the genetic susceptibility of cancers. However, there is a lack of in-depth characterization of the structural and functional impacts of the SNPs located at the TP63 gene. The current study was designed for the comprehensive characterization of the coding and non-coding SNPs in the human TP63 gene for their functional and structural significance. The functional and structural effects of the SNPs were investigated using a wide variety of computational tools and approaches, including molecular dynamics (MD) simulation. The deleterious impact of eight nonsynonymous SNPs (nsSNPs) affecting protein stability, structure, and functions was measured by using 13 bioinformatics tools. These eight nsSNPs are in highly conserved positions in protein and were predicted to decrease protein stability and have a deleterious impact on the TP63 protein function. Molecular docking analysis showed five nsSNPs to reduce the binding affinity of TP63 protein to DNA with significant results for three SNPs (R319H, G349E, and C347F). Further, MD simulations revealed the possible disruption of TP63 and DNA binding, hampering the essential protein function. PolymiRTS study found five non-coding SNPs in miRNA binding sites, and the GTEx portal recognized five eQTLs SNPs in single tissue of the lung, heart (LV), and cerebral hemisphere (brain). Characterized nsSNPs and non-coding SNPs will help researchers to focus on TP63 gene loci and ascertain their association with certain diseases.

RegQTLs: Single nucleotide polymorphisms that modulate microRNA regulation of gene expression in tumors.

Genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) associated with trait diversity and disease susceptibility, yet their functional properties often remain unclear. It has been hypothesized that SNPs in microRNA binding sites may disrupt gene regulation by microRNAs (miRNAs), short non-coding RNAs that bind to mRNA and downregulate the target gene. While several studies have predicted the location of SNPs in miRNA binding sites, to date there has been no comprehensive analysis of their impact on miRNA regulation. Here we investigate the functional properties of genetic variants and their effects on miRNA regulation of gene expression in cancer. Our analysis is motivated by the hypothesis that distinct alleles may cause differential binding (from miRNAs to mRNAs or from transcription factors to DNA) and change the expression of genes. We previously identified pathways—systems of genes conferring specific cell functions—that are dysregulated by miRNAs in cancer, by comparing miRNA–pathway associations between healthy and tumor tissue. We draw on these results as a starting point to assess whether SNPs on dysregulated pathways are responsible for miRNA dysregulation of individual genes in tumors. Using an integrative regression analysis that incorporates miRNA expression, mRNA expression, and SNP genotype data, we identify functional SNPs that we term “regulatory QTLs (regQTLs)”: loci whose alleles impact the regulation of genes by miRNAs. We apply the method to breast, liver, lung, and prostate cancer data from The Cancer Genome Atlas, and provide a tool to explore the findings.

Rs15869 at miRNA binding site in BRCA2 is associated with breast cancer susceptibility.

BRCA1 and BRCA2 mutations confer an increased lifetime risk of breast cancer; however, the associations of microRNA (miRNA) binding site single nucleotide polymorphisms (SNPs) in 3' untranslated region (3'-UTR) of BRCA1 and BRCA2 with breast cancer (BC) risk were rarely reported. In this case-control study (498 BC patients and 498 matched controls), three SNPs (rs8176318, rs12516 and rs15869) were selected in the 3'-UTR of BRCA1 and BRCA2 genes, which were within miRNA-binding seed regions and might have potential function to regulate the expression of BRCA1/BRCA2. Unconditional logistic regression model was used to analyze the association between three SNPs and BC risk with adjustment of reproductive factors, and Student's t test was performed to assess relative expression of BRCA2 in human breast cancer cell lines. Multifactor dimensionality reduction method was applied to calculate gene-reproductive factors interactions. A novel finding showed that AC [odds ratio (OR) 1.524; 95% confidence interval (CI) 1.141-2.035] genotype of rs15869 in BRCA2 could increase the risk of BC and recombinant plasmid-pGenesil-1-miR-627 could negatively regulate the expression of BRCA2 in MCF-7 and MDA-MB-231 cells. Gene-reproductive factors interactions analysis revealed that rs15869 together with age at menarche and number of pregnancy could increase the risk of BC by 2.39-fold and TT genotype (OR 0.316; 95% CI 0.130-0.767) of rs8176318 had a significant association with progesterone receptor status in BC patients. Our findings suggest that the miRNA-binding SNPs in BRCA1/BRCA2 and their interaction with reproductive factors might contribute to BC risk, and miR-627 might down-regulate BRCA2 expression in MCF-7 and MDA-MB-231 cells.

A genetic variation in microRNA target site of ETS2 is associated with clinical outcomes of paclitaxel-cisplatin chemotherapy in non-small cell lung cancer.

The present study was performed to investigate the association of single nucleotide polymorphisms (SNPs) located in the miRNA target sites with the clinical outcomes of first line paclitaxel-cisplatin chemotherapy in advanced NSCLC. Eighty SNPs in miRNA binding sites of cancer related genes selected from 18,500 miRNA:target bindings in crosslinking, ligation, and sequencing of hybrids (CLASH) data were investigated in 379 advanced NSCLC patients using a sequenom mass spectrometry-based genotype assay. qRT-PCR and luciferase assay were conducted to examine functional relevance of potentially functional SNPs in miRNA binding sites. Of the 80 SNPs analyzed, 16 SNPs were significantly associated with the clinical outcomes after chemotherapy. Among these, ANAPC1 rs3814026C>T, ETS2 rs461155A>G, SORBS1 rs7081076C>A and POLR2A rs2071504C>T could predict both chemotherapy response and survival. Notably, ETS2 rs461155A>G was significantly associated with decreased ETS2 mRNA expression in both tumor and paired normal lung tissues (Ptrend = 4 × 10−7, and 3 × 10−4, respectively). Consistently, a decreased expression of the reporter gene for the G allele of rs461155 compared with the A allele was observed by luciferase assay. These findings suggest that the four SNPs, especially ETS2 rs461155A>G, could be used as biomarkers predicting the clinical outcomes of NSCLC patients treated with first-line paclitaxel-cisplatin chemotherapy.

MicroRNA related polymorphisms and breast cancer risk.

Genetic variations, such as single nucleotide polymorphisms (SNPs) in microRNAs (miRNA) or in the miRNA binding sites may affect the miRNA dependent gene expression regulation, which has been implicated in various cancers, including breast cancer, and may alter individual susceptibility to cancer. We investigated associations between miRNA related SNPs and breast cancer risk. First we evaluated 2,196 SNPs in a case-control study combining nine genome wide association studies (GWAS). Second, we further investigated 42 SNPs with suggestive evidence for association using 41,785 cases and 41,880 controls from 41 studies included in the Breast Cancer Association Consortium (BCAC). Combining the GWAS and BCAC data within a meta-analysis, we estimated main effects on breast cancer risk as well as risks for estrogen receptor (ER) and age defined subgroups. Five miRNA binding site SNPs associated significantly with breast cancer risk: rs1045494 (odds ratio (OR) 0.92; 95% confidence interval (CI): 0.88–0.96), rs1052532 (OR 0.97; 95% CI: 0.95–0.99), rs10719 (OR 0.97; 95% CI: 0.94–0.99), rs4687554 (OR 0.97; 95% CI: 0.95–0.99, and rs3134615 (OR 1.03; 95% CI: 1.01–1.05) located in the 3′ UTR of CASP8, HDDC3, DROSHA, MUSTN1, and MYCL1, respectively. DROSHA belongs to miRNA machinery genes and has a central role in initial miRNA processing. The remaining genes are involved in different molecular functions, including apoptosis and gene expression regulation. Further studies are warranted to elucidate whether the miRNA binding site SNPs are the causative variants for the observed risk effects.

A polymorphism at the microRNA binding site in the 3′ untranslated region of C14orf101 is associated with non-Hodgkin lymphoma overall survival

MicroRNAs (miRNAs) can bind to the 3' untranslated regions (UTRs) of messenger RNAs, where they interfere with translation and thereby regulate cell differentiation, apoptosis, and tumorigenesis. Genetic polymorphisms in the 3' UTRs targeted by miRNAs alter the strength of miRNA binding in a manner that affects the behavior of individual miRNAs. In this study, four miRNA binding-site single nucleotide polymorphisms (SNPs) located in the 3' UTR of RYR3 (rs1044129), C14orf101 (rs4901706), KIAA0423 (rs1053667), and GOLGA7 (rs11337) were genotyped in non-Hodgkin lymphoma (NHL) patients to assess their relationships with cancer risk and overall survival. rs4901706, located in the 3' UTR of C14orf101, was shown to be independently related to overall survival in NHL patients by multivariate analysis (relative risk, 1.770; 95% CI, 1.046-2.996; P = 0.033). The prognostic value of this SNP on tumor overall survival was supported in diffuse large B-cell lymphoma patients with a P value of 0.095 and validated in T-cell lymphoma patients with a P value of 0.037.

Single Nucleotide Polymorphisms in MicroRNA Binding Sites of Oncogenes: Implications in Cancer and Pharmacogenomics

Cancer, a complex genetic disease involving uncontrolled cell proliferation, is caused by inactivation of tumor suppressor genes and activation of oncogenes. A vast majority of these cancer causing genes are known targets of microRNAs (miRNAs) that bind to complementary sequences in 3' untranslated regions (UTR) of messenger RNAs and repress them from translation. Single Nucleotide Polymorphisms (SNPs) occurring naturally in such miRNA binding regions can alter the miRNA:mRNA interaction and can significantly affect gene expression. We hypothesized that 3'UTR SNPs in miRNA binding sites of proto-oncogenes could abrogate their post-transcriptional regulation, resulting in overexpression of oncogenic proteins, tumor initiation, progression, and modulation of drug response in cancer patients. Therefore, we developed a systematic computational pipeline that integrates data from well-established databases, followed stringent selection criteria and identified a panel of 30 high-confidence SNPs that may impair miRNA target sites in the 3' UTR of 54 mRNA transcripts of 24 proto-oncogenes. Further, 8 SNPs amidst them had the potential to determine therapeutic outcome in cancer patients. Functional annotation suggested that altogether these SNPs occur in proto-oncogenes enriched for kinase activities. We provide detailed in silico evidence for the functional effect of these candidate SNPs in various types of cancer.

Variation within 3′-UTRs of Base Excision Repair Genes and Response to Therapy in Colorectal Cancer Patients: A Potential Modulation of microRNAs Binding

Colorectal cancer is routinely treated with a 5-fluorouracil (5-FU)-based chemotherapy. 5-FU incorporates into DNA, and the base excision repair (BER) pathway specifically recognizes such damage. We investigated the association of single-nucleotide polymorphisms (SNP) in the 3'-untranslated regions (UTR) of BER genes, and potentially affecting the microRNA (miRNA) binding, on the risk of colorectal cancer, its progression, and prognosis. SNPs in miRNA-binding sites may modulate the posttranscriptional regulation of gene expression operated by miRNAs and explain interindividual variability in BER capacity and response to 5-FU. We tested 12 SNPs in the 3'-UTRs of five BER genes for colorectal cancer susceptibility in a case-control study (1,098 cases and 1,459 healthy controls). Subsequently, we analyzed the role of these SNPs on clinical outcomes of patients (866 in the Training set and 232 in the Replication set). SNPs in the SMUG1 and NEIL2 genes were associated with overall survival. In particular, SMUG1 rs2233921 TT carriers showed increased survival compared with those with GT/GG genotypes [HR, 0.54; 95% confidence interval (CI), 0.36-0.81; P = 0.003] in the Training set and after pooling results from the Replication set. The association was more significant following stratification for 5-FU-based chemotherapy (P = 5.6 × 10(-5)). A reduced expression of the reporter gene for the T allele of rs2233921 was observed when compared with the common G allele by in vitro assay. None of the genotyped BER polymorphisms were associated with colorectal cancer risk. We provide the first evidence that variations in miRNA-binding sites in BER genes 3'-UTR may modulate colorectal cancer prognosis and therapy response.

A miRNA Binding Site Single-Nucleotide Polymorphism in the 3′-UTR Region of the IL23R Gene Is Associated with Breast Cancer

BackgroundResearch into the etiology of breast cancer has recently focused on the role of the immunity and inflammation. Interleukin-23 and its receptor (IL23R) guide T cells towards the Th17 phenotype. IL23R single nucleotide polymorphisms (SNPs) have been shown to be associated with digestive system cancers. To evaluate the influences of IL23R gene polymorphisms on the risk of sporadic breast cancer, a case-control study was conducted in Chinese Han women.Methodology and Principal FindingsWe genotyped two tag SNPs (rs10889677 in the 3′-UTR region and nonsynonymous variants rs1884444 in exon 2) in IL23R gene of 491 breast cancer patients and 502 matched healthy controls. The genotypes were determined using the SNaPshot technique. The differences in the genotypic distribution between breast cancer patients and healthy controls were analyzed with the Chi-square test for trends. For rs10889677 in IL23R, the frequencies of the AA genotype and the A allele were statistical significant higher in breast cancer patients than in controls (P = 0.0084 and P = 0.0171, respectively), whereas the C allele was associated with an earlier age of breast cancer onset (50.6 years for AA, 48.7 years for AC and 46.0 years for CC (P = 0.0114)) in case-only study. The clinical features analysis demonstrated significant associations between rs1884444 in IL23R and human epidermal growth factor receptor 2 (Her-2) and tumor size status.Conclusions and SignificanceOur results suggest that a miRNA binding site SNP in the 3′-UTR region of the IL23R gene may be associated with the risk of breast cancer and contribute to the early development of breast cancer in Chinese women.

Abstract 2927: MicroRNA binding site polymorphisms influence ovarian cancer risk in the collaborative oncological gene-environment study

Abstract Mi(cro)RNAs are short non-coding RNA molecules that play a key role in carcinogenesis by regulating tumor suppressors and oncogenes. Published data has implicated miRNAs in ovarian cancer (OC) development and progression, and we hypothesize that single nucleotide polymorphisms (SNPs) in sites of miRNA: messenger RNA (mRNA) binding may influence OC risk by altering expression levels of targeted mRNAs. To evaluate associations between SNPs in miRNA binding sites and OC risk, we used bioinformatics tools and public databases to identify miRNA binding SNPs relevant to ovarian cancer. We then evaluated the frequency of approximately 1,100 SNPs in ∼20,000 epithelial OC cases and 20,000 controls represented in the international Collaborative Oncological Gene-environment Study. Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) between genotypes and case status, with adjustment for the first five principal components representing European ancestry. Log-additive genetic models were applied to each SNP, modeling the number of copies of the minor allele. Subgroup analysis was conducted for serous adenocarcinomas, the most predominant histologic subtype of epithelial OC. Preliminary analysis of 11,215 invasive epithelial OCs and 15,910 controls included four SNPs with P<10−6 and 1 SNP with P<10−5. Analysis of 6,215 invasive serous adenocarcinomas revealed two SNPs with P<10−7 and three SNPs with P<10−6. Noteworthy is rs6104808, a C>T SNP predicted to reside in a highly conserved miRNA binding site of BTBD3 (BTB POZ domain containing 3), a transcription factor suggested to be involved in cell proliferation, cancer progression, and response to platinum-based chemotherapy. rs6104808 was associated with a decreased risk of OC overall (OR (95% CI): 0.42 (0.28-0.62), P=1.26 x 10−5)), and the association was stronger among cases with serous adenocarcinoma (OR (95% CI): 0.30 (0.17-0.50), P=9.89 x 10−6)). This represents the largest, most comprehensive epidemiologic study to date to evaluate associations between miRNA binding site SNPs and OC susceptibility. Although based on a preliminary analysis, these data suggest a significant role and putative biological mechanism for common germline variants in miRNA binding sites leading to cancer development. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2927. doi:1538-7445.AM2012-2927

MicroRNA-related genetic variations as predictors for risk of second primary tumor and/or recurrence in patients with early-stage head and neck cancer

Second primary tumor (SPT) and/or recurrence negatively impact the prognosis of patients with curatively treated early-stage head and neck cancer. MicroRNAs (miRNAs) play important roles in cancer development. We explored whether the variations of miRNA-related pathway were associated with the risk of SPT/recurrence in patients with early-stage head and neck cancer. This study includes 150 early-stage head and neck cancer patients with SPT/recurrence and 300 patients without SPT/recurrence. Two hundred and thirty-five tagging and potentially functional single-nucleotide polymorphisms (SNPs) were genotyped from eight miRNA biogenesis pathway genes and 135 miRNA-targeted genes. Eighteen miRNA-related SNPs were significantly associated with the risk of SPT/recurrence. The most significant SNP was rs3747238, a miRNA-binding site SNP in SMC1B. The variant homozygous genotype of this SNP was associated with a 1.74-fold increased risk [95% confidence interval (CI) 1.19-2.54; P = 0.004]. Cumulative effect analysis showed joint effects for the number of unfavorable genotype in patients. Survival tree analysis further identified the high-order gene-gene interactions and categorized the study subjects into low-, medium- and high-risk groups. Patients in the high-risk group had a 4.84-fold increased risk (95% CI: 3.11-7.51; P = 2.45 × 10(-12)) and a shorter event-free median survival time of 37.9 months (log rank P = 2.28 × 10(-13)). Our results suggested that miRNA-related genetic polymorphisms may be used individually and jointly to predict the risk of SPT/recurrence of early-stage head and neck cancer patients.