Binding Site Polymorphism Research Articles

MiRNA-767 and its binding site polymorphism in the mTOR gene act as potential biomarkers for female reproductive cancers.

Aims: The present study aimed to understand the relationship between the mTOR gene SNP (rs2536) and reproductive cancer risk. The expression level of miRNA-767 was also assessed. Methods: 700 tumor samples (300 breast, 200 ovarian and 200 cervical cancers), along with adjacent uninvolved control tissue, were used. rs2536 was screened using Tetra-ARMS PCR and expression level of miRNA-767 was assessed using quantitative PCR. Results: The frequency of the homozygous mutant genotype of rs2536 was observed significantly higher in breast (p<0.04), ovarian (p<0.005) and cervical (p<0.003) cancers. Significant downregulation of miRNA-767 was observed in tumors compared with controls. Conclusion: The present study demonstrates that increased mutant frequency of rs2536 and deregulation of miRNA-767 are associated with increased reproductive cancer risk.

The IRF6 AP-2α binding site polymorphism relate to the severity of non-syndromic orofacial cleft of Indonesian patients.

IRF6 AP-2α binding site polymorphism is known as IRF6 rs642961. It has been associated with a nonsyndromic orofacial cleft (NS OFC). This study aimed to determine the IRF6 rs642961 as a risk factor associated with NS OFC and its phenotypes. The case-control design used for 264 subjects consists of 158 NS CLP subjects (42 CU CLP, 34 CB CLP, 33 CLO, 49 CPOs) and 106 healthy controls. The DNA is extracted from venous blood. The segment of IRF6 rs642961 amplified by polymerase chain reaction (PCR) followed by restriction fragment length of polymorphisms (RFLPs) used the MspI digestion enzyme. The qPCR method to identify the mRNA expression levels of the IRF6 gene rs642961 was analyzed by the Livak method. The study results show that in NS CB CLP phenotype as the most severe phenotype of NS OFC, the Odds Ratio (OR) of A mutant allele was 5.094 (CI=1.456-17.820; P=0.011) and the OR of AA homozygous mutant genotype was 13.481 (CI=2.648-68.635; P=0.001). There are different levels of mRNA expression changes from NS OFC and its phenotypes. It is substantial among the 2-ΔΔCt and the group of AA, GA, and GG genotypes (P<0.05); in the NS CPO phenotype, it shows IRF6 mRNA under-expression in GA, AA genotypes while in other phenotypes it shows IRF6 mRNA overexpression. The IRF6 AP-2α binding site polymorphism is strongly associated with the severity of NS OFC, and this polymorphism has a functional role in affecting IRF6 mRNA expression that is variable in each phenotype.

1110. AZD7442 (Tixagevimab/Cilgavimab) Demonstrates Potent In Vitro Activity Against SARS-CoV-2 Spike Variants Identified in Circulation and in Prophylaxis Clinical Studies

Abstract Background AZD7442 is a combination of extended–half-life SARS-CoV-2–neutralizing monoclonal antibodies (tixagevimab/cilgavimab) that bind to distinct epitopes on the SARS-CoV-2 spike protein. In the PROVENT study, a single 300 mg intramuscular dose of AZD7442 demonstrated 77% efficacy for prevention of COVID-19 vs placebo at primary analysis, with 83% efficacy through 6-months follow-up, and was well-tolerated. We report conservation of AZD7442 binding sites and neutralizing activity against pseudotyped virus-like particles (VLPs) harboring spike substitutions identified in surveillance, and clinical SARS-CoV-2 isolates from the PROVENT study. Methods Consensus SARS-CoV-2 whole genome sequences were analyzed from open source databases to identify prevalent spike substitutions within the AZD7442 binding site. Phenotypic analyses determined neutralization susceptibility of pseudotyped VLPs with identified spike substitutions. Genotypic analyses were also performed on SARS-CoV-2 spike sequences from PROVENT study (NCT04625725) participants with RT-PCR-positive symptomatic illness. Results Most residues in tixagevimab (13/17) and cilgavimab (13/19) binding sites were &amp;gt;99% conserved among global SARS-CoV-2 isolates (N=8,373,740 through Apr 19, 2022). In 2021, AZD7442 binding site polymorphisms emerged among circulating strains (prevalence: R346K, 11%; N440K, 22%; G446S, 15%; S477N, 28%; L452R, 43%; T478K, 70%; E484A, 27%; E484K, 3%; Q493R, 27%), but these did not affect AZD7442 in vitro neutralization potency. AZD7442 retained neutralization activity against variants of concern or interest tested, including Omicron BA.2, with moderate reduction observed for Omicron BA.1. By median 6-months follow-up (Aug 29, 2021, data cut-off) in the PROVENT study, there were no AZD7442-resistant substitutions observed in breakthrough SARS-CoV-2 illness visits. Conclusion AZD7442 retained neutralization activity against all SARS-CoV-2 variants of concern or interest evaluated. Binding site substitutions identified in circulation, and in breakthrough SARS-CoV-2 infections following a single 300 mg dose of AZD7442 in the PROVENT study, were not associated with AZD7442 escape. Disclosures Kevin M. Tuffy, MS, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Michael E. Abram, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Tiffany L. Roe, B.S., AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Bahar Ahani, BSC, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Tyler Brady, MS, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Nicolette Schuko, MS, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Lori Clarke, B.S., AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Carolina Caceres, MS, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Tara Kenny, MS, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Virginia Takahashi, B.S., AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Tianhui Zhang, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds David E. Tabor, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Gustavo H. Kijak, PharmD PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Elizabeth J. Kelly, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Katie Streicher, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds.

A microRNA binding site polymorphism in the 3\u2032 UTR region of VEGF-A gene modifies colorectal cancer risk based on ethnicity: a meta-analysis

BackgroundVascular endothelial growth factor A (VEGF-A) plays an integral role in angiogenesis by contributing to growth, development, and metastasis of solid tumors. Recently, a single-nucleotide polymorphism +936C/T located in the VEGF-A 3′ untranslated region (UTR) facilitated the susceptibility of colorectal cancer. The association between VEGF-A gene polymorphism +936C/T and colorectal cancer risk has been widely studied in the last decade, but presently, the results furnished remain enigmatic. Hence, the study aimed to investigate the association between VEGF-A +936C/T miRNA binding site polymorphism and the risk of developing colorectal cancer.MethodsThis meta-analysis included 13 published case-control studies covering 3465 cases (colorectal cancer) and 3476 healthy controls. Publication bias was examined by means of Begg’s funnel plots and Egger’s regression tests. The quality of the studies included was evaluated using Newcastle-Ottawa scale. Subgroup analyses were performed in accordance to the various ethnicities of the study subjects and the study quality.ResultsFrom the data obtained, it is implied that VEGF-A +936C/T polymorphism did not correlate with elevated colorectal cancer risk in all genetic models. But the results acquired from the subgroup analysis in over dominant model (CT vs. CC + TT: OR = 1.5047, 95% CI = 1.19–1.90) suggest that VEGF-A +936C/T polymorphism leads to the raise in the risk of developing CRC among the East Asian population. No association was observed in Caucasian and South Asian population.ConclusionsOur results indicate that VEGF-A +936C/T polymorphism is not a risk factor for developing CRC in Caucasian and South Asian population. However, the East Asian population was related to an increased risk of developing colorectal cancer due to the presence of the minor allele.

Выделение и PBS-дифференциация изолятов Alternaria spp.

Abstract. The purpose of the study. Isolation of Alternaria sp. and their PBS differentiation. The article presents the results of isolation of phytopathogenic fungi of the genus Alternaria spp. from wheat plants and their genetic differentiation using iPBS (Inter Primer Binding Site Polymorphism) analysis. As a result of monitoring studies, it was shown that the fungi Alternaria spp. are the dominant component of the pathocomplex of fungi affecting the embryonic zone of seeds and ears of wheat in the northern regions of Kazakhstan. The pathocomplex of Alternaria is formed by isolates of A. alternata, A. infectoria, and A. tenuissima. Methods. Genetic differentiation of the isolates was performed using iPBS analysis. This method is based on the use of conserved sequences of tRNA binding sites (Primer Binding Sites) as PCR primers. This method is versatile and effective for the direct detection of polymorphism between individuals; therefore, PBS primers can be used in almost any organism, including fungi. Results. Analysis of the PBS primers showed that they all have high resolution in the differentiation of Alternaria spp. The obtained amplification products showed high variability among isolates, both within one species and at the interspecies level. The level of detectable polymorphism varied from 47.43 % to 80.81 %, with an average of 61 %. The size of the amplified PCR fragments ranged from 200 to 3000 bp; on average, amplification was observed from 5 to 15 bands per isolate. Practical significance. This work made it possible to obtain new data on the genetic diversity of Alternaria phytopathogenic fungi for the subsequent development of a strategy for plant protection against Alternaria.

IPBS-полиморфизм редких реликтовых и исчезающих видов Allium, произрастающих на территории Казахстанского Алтая

Abstract. The purpose of the study. The estimation of genetic polymorphism of Kazakhstan populations of rare relict and endemic Allium species. The novelty of the research is the use of the modern molecular genetic iPBS (Inter- Primer Binding Site Polymorphism) method of DNA amplification to assess the genetic diversity of different populations of Allium sp., collected in their natural habitats in the Kazakhstan Altai. Methods. Samples of medicinal relict and endangered species A. ledebourianum, A. altaicum, A. microdiction were collected in the places of their natural growth in the territory of the Kazakhstan Altai. DNA was isolated from 3–5 day sterile seedlings using lysis STAB buffer with RNaseA. PBS primers were used to assess the genetic diversity of different populations of Allium spp. The amplification results obtained using different PBS primers were evaluated in the GenAlex 6.5 macro program for Excel. Results. The polymorphism of 16 genotypes of the rare relict and endangered Allium sp. was analyzed using 7 PBS primers. Clearly distinguishable amplicons were obtained, the number of which varied depending on the primer used. The dendrogram, based on UPGMA analysis, grouped the studied genotypes into 2 main clusters, one of which included samples from the A. altaicum population, and the second cluster included samples from the A. ledebourianum population. A. microdiction represented by one sample did not enter any cluster, and formed a basal branch in the dendrogram. The results of the study have revealed a high degree of iPBS polymorphism and genetic diversity in rare relict and endangered Allium sp. Practical significance. The use of the molecular genetic iPBS method allows to identify a high level of polymorphism, which can serve as a basis for the identification of various genotypes of the Allium sp., which will significantly supplement traditional preservation methods of natural populations of this genus.

Frequency of MicroRNA Response Elements Identifies Pathologically Relevant Signaling Pathways in Triple-Negative Breast Cancer.

SummaryComplex interactions between mRNAs and microRNAs influence cellular functions. The mRNA-microRNA interactions also determine the post-transcriptional availability of mRNAs and unbound microRNAs. MicroRNAs binds to one or more microRNA response elements (MREs) located on the 3′UTR of mRNAs. In this study, we leveraged MREs and their frequencies in cancer and matched normal tissues to obtain insights into disease-specific interactions between mRNAs and microRNAs. We developed a bioinformatics method “ReMIx” that utilizes RNA sequencing (RNA-Seq) data to quantify MRE frequencies across the transcriptome. We applied ReMIx to triple-negative (TN) breast cancer tumor-normal adjacent pairs and identified MREs specific to TN tumors. ReMIx identified candidate mRNAs and microRNAs in the MAPK signaling cascade. Further analysis of MAPK gene regulatory networks revealed microRNA partners that influence and modulate MAPK signaling. In conclusion, we demonstrate a novel method of using MREs in the identification of functionally relevant mRNA-microRNA interactions in TN breast cancer.

COLIA1 + 1245 G > T Sp1 Binding Site Polymorphism is Not Associated with ACL Injury Risks Among Indian Athletes.

Type I collagen polypeptides contribute significantly to the structural composition of ligament tissue matrix. Since anterior cruciate ligament (ACL) tears account for roughly 50% of all knee injuries in sports, the objective of the study was to investigate association of Sp1-transcription factor binding site polymorphism COLIA1 Sp1 + 1245 G > T with ACL injury risk among Indian athletes. A total of 166 athletes (90 with ACL tears and 76 as control) were recruited and were genotyped for COLIA1 Sp1 + 1245 G > T polymorphism using allele-specific PCR (AS-PCR) method. Both the groups were matched for nature of sports, training regimen, and other demographic characteristics. We observed no significant difference between ACL cases and control group in GT or TT genotype frequency distribution (p = 0.967) and T-allele frequency distribution (p = 0.861) for COLIA1 Sp1 + 1245 G > T polymorphism. Also, the three models of inheritance of minor allele failed to show any statistical significance in the present study. COLIA1 Sp1 + 1245 G > T polymorphism has been studied in relation to many connective tissue pathologies. This is probably the first study to investigate the association of collagen protein genes with ACL injury risk on Indian athletes. Further studies with more SNPs in genes encoding fibril-forming collagen and large sample sizes are necessary to fully understand the genetic link to ACL injuries among athletes.

MicroRNA Binding Site Polymorphisms of the Long-Chain Noncoding RNA MALAT1 are Associated with Risk and Prognosis of Colorectal Cancer in Chinese Han Population

Background: The metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) gene's rs664589 locus is located within the binding site of the miRNA hsa-miR-194-5p for its cognate long-chain noncoding RNA (lncRNA) MALAT1. The aim of this study was to investigate the association between the rs664589 single nucleotide polymorphism (SNP) and the risk and prognosis of colorectal cancer (CRC) in the Chinese Han population. Methods: A cohort of 340 patients with CRC who underwent surgical resection and another group of 340 healthy subjects were enrolled in this study and analyzed for their rs664589 genotypes. In addition, quantitative real-time-polymerase chain reaction was used to detect the expression levels of the lncRNA MALAT1 and the hsa-miR-194-5p in cancer tissues and paracancerous normal tissues of CRC patients. Results: The risk of CRC in subjects carrying the G allele at the rs664589 locus in the 3' untranslated region of the MALAT1 gene was 1.81 times higher than for C allele carriers. The expression levels of the lncRNA MALAT1 in cancer tissues was significantly higher than that in paracancerous tissues, while the hsa-miR-194-5p expression level was significantly lower in cancerous tissues compared to cognate paracancerous tissues. The progression-free survival (PFS) rate for patients with the MALAT1 gene rs664589 locus GG genotype was significantly lower than that of CG genotype patients. Moreover, lncRNA MALAT1 inhibited the expression of hsa-miR-194-5p. Conclusion: The risk of CRC was relatively higher among MALAT1 rs664589 G allele carriers, and the CRC patients with a G allele had a lower PFS. The likely mechanism underlying these observations is that the rs664589 SNP affects the binding efficiency between the lncRNA MALAT1 and the miRNA has-miR-194-5p, although this awaits laboratory confirmation.

MicroRNA binding site polymorphism in inflammatory genes associated with colorectal cancer: literature review and bioinformatics analysis.

Inflammation, among environmental risk factors, is one of the most important contributors to colorectal cancer (CRC) development. In this way, studies revealed that the incidence of CRC in inflammatory bowel disease patients is up to 60% higher than the general population. MicroRNAs (miRNAs), small noncoding RNA molecules, have attracted excessive attention due to their fundamental role in various aspects of cellular biology, such as inflammation by binding to the 3'-untranslated regions (3'-UTR) of pro and anti-inflammatory genes. Based on multiple previous studies, SNPs at 3'-UTR can affect miRNA recognition elements by changing the thermodynamic features and secondary structure. This effect can be categorized, based on the number of changes, into four groups, including break, decrease, create, and enhance. In this paper, we will focus on functional variants in miRNA binding sites in inflammatory genes, which can modulate the risk of CRC by both investigating previous studies, regarding miRSNPs in inflammatory genes associated with CRC and recruiting in silico prediction algorithms to report putative miRSNPs in 176 inflammatory genes. In our analysis, we achieved 110 miRSNPs in 3'-UTR of 67 genes that seem good targets for future researches.

An Effective and Viable DNA Extraction Protocol for FFPE Tissues and its Effect on Downstream Molecular Application

Archival Formalin-Fixed Paraffin-Embedded (FFPE) tissues are a readily available source of DNA for retrospective studies including genetic predisposition. FFPE tissues present significant challenges for extraction of pure genomic DNA in adequate amounts due to the harsh fixation conditions and long-term storage associated with samples. The aim of the study is to propose a simple, in-expensive, viable protocol for the extraction of DNA from FFPE tissues and to optimize the same for the detection of 3’UTR miRNA binding site polymorphism in ADAMTS1 gene in colorectal cancer tissues and normal colonic mucosa archival tissues using Sanger sequencing and TaqMan SNP genotyping assay. Five different DNA extraction methods were compared and analyzed. NanoDrop quantification demonstrated that out of the various methods tested, highest quantity and pure DNA was obtained from Modified non heating extraction. When we further applied this method for colorectal cancer tissues and normal colonic mucosa archival tissues the NanoDrop readout indicated that the DNA was intact and pure. Intra samples comparison over a time period of 6 months revealed that the DNA was intact. The samples isolated with Modified non heating extraction were found suitable for downstream processes such as Sanger sequencing and TaqMan SNP genotyping assay. This cost effective and non-arduous protocol can successfully extract even minute quantities of DNA from FFPE tissues and facilitate the downstream molecular analysis of a large number of archival specimens for retrospective studies.

SMADs binding site polymorphisms rs9911630 is associated with susceptibility but not prognosis of gastric cancer: a case control study.

Background: Single nucleotide polymorphisms (SNPs) in transcription factor binding sites (TFBS) can change their binding strength, affecting the function of transcription factors (TFs). Small mother against decapentaplegic (SMAD) proteins are known as a family of TFs involved in tumorigenesis. We performed this study to investigate whether SNPs in SMADs binding sites affect the susceptibility or prognosis of gastric cancer (GC).Methods: Using bioinformatics tools, we focused on the association between rs9911630 polymorphism and GC. We performed this case-control study in 1275 GC patients and 1426 cancer-free subjects using TaqMan allelic discrimination method.Results: We found that rs9911630 A>G polymorphism was associate to an increased risk of gastric cancer (adjusted OR for additive model = 1.16; 95% CI = 1.03-1.30). Furthermore, we assess whether rs9911630 polymorphism affected the prognosis of GC. However, no significant association was discovered between rs9911630 A>G polymorphism and overall survival time of GC patients (HR for addictive model = 1.01; 95%CI = 0.88-1.15).Conclusions: Our results suggested that rs9911630 polymorphism in SMADs target site might influence susceptibility but not prognosis of gastric cancer.

Association between microRNA binding site polymorphisms in immunoinflammatory genes and recurrence risk of ischemic stroke

MicroRNA binding site polymorphisms in immunoinflammatory genes have been implicated as candidate biomarkers for prediction of complex human diseases. However, the roles of microRNA binding site polymorphisms in stroke onset and prognosis remain unclear. Thus, for the first time, five potential functional polymorphisms in immunoinflammatory genes (CXCR2 rs1126579, TLR4 rs11536889, ADIPOR2 rs12342, MMP-2 rs7201 and MMP-9 rs1056628) were genotyped in 657 patients with ischemic stroke. These five polymorphisms were not related with age onset of ischemic stroke. However, we found that ADIPOR2 rs12342 was significantly associated with a decreased recurrence risk, especially for the patients with small-vessel disease. Moreover, by using multivariate Cox regression, the variant genotype GG/GA of rs12342 was observed as an independent protective factor for stroke recurrence, even after Bonferroni correction. In addition, after the addition of rs12342 in the model with clinical factors, the new model showed the improved discriminatory ability to predict stroke recurrence. In short, our results suggested that ADIPOR2 rs12342 may be a novel genetic biomarker and therapeutic target for ischemic stroke recurrence. Further studies are required to replicate our findings and clarify the potential biological mechanism.

Habitat-related specifity of iPBS fingerprint in European populations of Hedera helix L.

Abstract Inter primer binding site (iPBS) polymorphism was investigated for common ivy (Hedera helix, L.) to obtain the knowledge on genetic diversity in this species. Actually, a very limited information exists about application of DNA markers in Hedera helix. Natural and planted European populations of ivy were analysed using an iPBS marker 5′ACCTGGCGTGCCA3′ with a total number of 238 fragments generated. Of these, 86% were polymorphic. There were determined certain attributes of this marker such as the diversity index (DI) and polymorphism information content (PIC). The value of the diversity index was 0.79 and the polymorphic information index was 0.78. The proportion of polymorphisms of the individual amplified loci ranged from 0.32% to 6.98%. Cluster analysis was performed to determine the relationships among the European ivy populations where the distribution in the dendrogram under the habitat specifity was found for the used iPBS marker. We concluded that iPBS was very efficient in analysing the genetic diversity in Hedera helix, L. and that this marker can serve as a suitable tool to find genomically specific fingerprints relevant to the factors influencing the distribution of genetic variation.

The role of miRNA genes participating in VHL-HIF1α in clear cell renal cell carcinoma

Introduction. Much attention in ccRCC development is paid to VHL-HIF1α pathway genes. Numerous genes involved in the pathogenesis of ccRCC are targets for miRNA. Alteration in the nature of interaction with miRNA binding site as a result of a single nucleotide substitution may promote change the expression of target genes involved in the genesis and development of tumors.Purpose of research. Analysis of the role of polymorphic variants in the miRNA binding sites of the VHL-HIF1α gene pathways in ccRCC development.Materials and methods. We used 225 DNA samples isolated from the venous blood of ccRCC patients who are hospitalized to the Clinic of the Bashkir State Medical University, and 298 healthy individuals. The genotyping of miRNA binding site polymorphisms in VHL-HIFα-dependent pathway genes (rs10982724 of the DEC1 gene, rs406271 of the TFRC gene, rs10491534 of the TSC1 gene, rs1642742 of the VHL gene, rs3025033 of the VEGFA gene) was performed using Taq-man assays.Results. The frequency distribution of alleles and genotypes of rs1642742 of the VHL gene showed that rs1642742 *GG is a marker of the increased risk for ccRCC. In addition, rs10491534 * C allele was found to be the marker for severe ccRCC (p = 0.044; OR = 1.72 (CI = 1.012-2.911)), and rs10491534 * TT genotype (p = 0.044; OR = 0.55; (95% CI = 0.31–0.98)) of the TSC1 gene was shown to be a protective marker for ccRCC of severe duration.Conclusions. The study indicated the association of miRNA binding sites polymorphisms with the risk of ccRCC development and severity of disease. However, further studies of the genes are needed to establish their functional significance and role in the pathogenesis of ccRCC.

Estimation of genomic instability and DNA methylation due to aluminum (Al) stress in wheat ( Triticum aestivum L.) using iPBS and CRED-iPBS analyses

Aluminum (Al) toxicity is a serious factor restricting crop productivity in acid soil, and Al is the major cause of phytotoxicity. However, the role of Al toxicity in interprimer binding site (iPBS) polymorphism, genomic instability, and DNA methylation has not been fully investigated. In the current study, the effects of different Al concentrations on iPBS polymorphism, genomic instability, and DNA methylation were investigated in seedlings of three wheat cultivars: Haymana 79, Kilciksiz, and Bezostaja 1. A higher aluminum concentration increased the polymorphism rate of the iPBS profile, but decreased genomic template stability in all cultivars . A higher Al concentration was found to cause DNA methylation. Furthermore, the coupled restriction enzyme digestion-iPBS technique was used to detect DNA cytosine methylation level, which could help in understanding the epigenetic mechanism. The occurrence of hypermethylation and hypomethylation was observed with respect to Al stress treatment, and Al was found to cause DNA methylation. Polymorphism in the CRED-iPBS profile and DNA methylation can be correlated to evaluate epigenetic changes under stress.

A miR-18a binding-site polymorphism in CDC42 3′UTR affects CDC42 mRNA expression in placentas and is associated with litter size in pigs

Increasing evidence suggests that miRNA binding-site polymorphism in the 3'-untranslated region (3'UTR) of a target gene could affect that gene's expression, and can be associated with a variety of complex traits. In this study, we find that miR-18a and cell division cycle 42 (CDC42) mRNA, whose expression was inversely correlated, are differentially expressed in porcine placentas during critical stages of placental development. rs55618224 (T>C), a SNP in the 3'UTR region of CDC42 that is perfectly complementary to the miR-18a seed could influence miR-18a-related regulation of CDC42 gene by altering their binding affinity. In addition, CDC42 mRNA was found to have higher expression level in the homozygous TT placentas as compared to those homozygous CC placentas in pigs. Furthermore, we identified a significant association between rs55618224 and total number born per litter. These results suggest the miR-18a binding-site polymorphism in CDC42 3'UTR may impact litter size by regulation of CDC42 gene in porcine placentas.

Promoter expression of HERV-K (HML-2) provirus-derived sequences is related to LTR sequence variation and polymorphic transcription factor binding sites

BackgroundIncreased transcription of the human endogenous retrovirus group HERV-K (HML-2) is often seen during disease. Although the mechanism of its tissue-specific activation is unclear, research shows that LTR CpG hypomethylation alone is not sufficient to induce its promoter activity and that the transcriptional milieu of a malignant cell contributes, at least partly, to differential HML-2 expression.ResultsWe analyzed the relationship between LTR sequence variation and promoter expression patterns in human breast cancer cell lines, finding them to be positively correlated. In particular, two proviruses (3q12.3 and 11p15.4) displayed increased activity in almost all tumorigenic cell lines sampled. Using a transcription factor binding site prediction algorithm, we identified two unique binding sites in each 5′ LTR that appeared to be associated with inducing promoter activity during neoplasia. Genomic analysis of the homologous proviruses in several non-human primates indicated post-integration genetic drift in two transcription factor binding sites, away from the ancestral sequence and towards the active form. Based on the sequences of 2504 individuals from the 1000 Genomes Project, the active form of the 11p15.4 site was found to be polymorphic within the human population, with an allele frequency of 51%, whereas the activating mutation in the 3q12.3 provirus was fixed in humans but not present in the orthologous provirus in chimpanzees or gorillas.ConclusionsThese data suggest that stage-specific transcription factors at least partly contribute to LTR promoter activity during transformation and that, in some cases, transcription factor binding site polymorphisms may be responsible for the differential HML-2 expression often seen between individuals.

Functional Polymorphism Located in the microRNA Binding Site of the Insulin Receptor (INSR) Gene Confers Risk for Type 2 Diabetes Mellitus in the Bangladeshi Population.

Bangladesh has the second largest number of adults with diabetes in South Asia. Compelling evidence suggest that miRNAs contribute to the etiology of Type 2 diabetes mellitus (T2DM) by regulating many aspects of glucose homeostasis. Hence, we hypothesized that genetic polymorphisms in the diabetes-related miRNA target-binding sites could be associated with the risk of T2DM in Bangladesh. The reference Single nucleotide polymorphism (SNP) data from the Insulin Receptor (INSR) gene were downloaded from the ENSEMBL genome browser release 88 and further analyzed in silico for identifying SNPs with deleterious effect and clinical relationships. Further, case-control study using the microRNA-binding site polymorphism rs1366600 (T > C) located at the 3' UTR of the INSR gene was carried out in 217 T2DM patients and 237 healthy controls from Bangladesh. Genotyping was performed using the real time PCR based allele discrimination method. The results showed that the minor allele 'C' is associated with increased risk of T2DM [Odds ratio (OR) 1.87; 95% confidence intervals (CI) 1.28-2.74; P = 0.0010]. When we dissected our analysis to include the dominant model (CC + TC genotype against the TT genotype), we found that the CC and TC genotypes were associated with increased risk of T2DM in Bangladeshi population (OR 2.01; 95% CI 1.31-3.07; P = 0.0012). However, in recessive model (CC vs TT + TC); the effect was not statistically significant (OR 2.23; 95% CI 0.66-7.51; P = 0.1848). Stratification of our data based on the gender of the cases and controls showed similar degree of risk association with respect to different genotypes and alleles. Our study showed that the miRNA binding site polymorphism rs1366600 located at the 3'-UTR region of the INSR gene is associated with increased risk of T2DM in Bangladeshi individuals.

Genotype and allele frequencies of TYMS rs2790 A > G polymorphism in a Chinese paediatric population with acute lymphoblastic leukaemia.

Thymidylate synthase (TYMS) is an important target for methotrexate (MTX). Genetic variations in the TYMS gene contribute to the differences in treatment responses to MTX. The aim of this study was to investigate the distribution of a microRNA (miRNA) binding site polymorphism (rs2790 A>G) in the 3'-untranslated region (3'-UTR) of TYMS and its association with MTX concentration and haematological toxicity in Chinese paediatric patients with acute lymphoblastic leukaemia (ALL). The Sequenom MassARRAY system was used for TYMS rs2790 A>G genotyping in 118 children with ALL. Serum MTX concentrations were measured by a fluorescence polarization immunoassay. Clinical data were extracted from the electronic medical records. The minor allele frequency noted in this study (39.8%) was significantly higher than those in the CEU (Utah residents with northern and western Europe ancestry; 16.2%) and YRI (Yoruba in Ibadan, Nigeria; 25.0%) samples reported in the 1000 Genomes Project (P<.01). The frequency of MTX level >40μmol/L at 24hours in patients with the AA genotype (36.6%) was significantly higher than that in GG genotype carriers (5.9%, P<.05). However, the incidence rates of haematological toxicity were similar in the three genotype groups. Whereas there was evidence of higher blood levels in the A homozygotes, the evidence for this translating to higher toxicity was lacking. A larger study would be required to answer this. The results of this study confirmed the significant ethnic differences in the distributions of the TYMS rs2790 A>G polymorphism. Whereas there was evidence of differences in MTX blood levels according to genotype, our study was not powered to show whether this would lead to more haematological toxicity.