Clinical and molecular genetics association of polymorphisms in interleukin-17A genes with risk of Oral Lichen Planus (OLP) in an Azery population

Lichen Planus (LP) is a chronic disease that affects the skin and oral mucosa. Although the precise aetiology of LP is not known, it is thought to be comprised of, in majority, genetic and immunological factors. The objective of this study was to assess the association of interleukin-17A (IL-17A) with Oral LP (OLP). 22 adult patients with OLP and 40 healthy controls were genotyped by polymerase chain reaction (PCR) and DNA direct   sequence technology for the polymorphism of the IL-17A gene. The genotype frequencies of G1776A  (p.Arg29Ter rs139620979) and G3566A (rs7747909) in the IL-17A gene polymorphism were 9 and 13.6% in the OLP group and 0 and 40% in the controls, respectively. Although the proportion of detected polymorphisms did not differ between individuals, a higher prevalence of G3566A (rs7747909) homozygote polymorphism (4.5%) was observed in the OLP patients. Our results show no statistically significant difference in the IL-17A  genotype single nucleotide polymorphisms (SNPs) distribution amongst the two groups. Therefore, further  studies on a larger population and novel genetic variants are needed to better understand the pathobiology of OLP.Key words: Oral Lichen Planus (OLP), interleukin-17A (IL-17A) gene, single nucleotide polymorphisms (SNPs), direct sequencing

Microsatellite instability in colorectal cancer

Colorectal cancer (CRC) is a heterogeneous disease that is caused by the interaction of genetic and environmental factors. Although it is one of the most common cancers worldwide, CRC would be one of the most curable cancers if it is detected in the early stages. Molecular changes that occur in colorectal cancer may be categorized into three main groups: 1) Chromosomal Instability (CIN), 2) Microsatellite Instability (MSI), and 3) CpG Island Methylator phenotype (CIMP). Microsatellites, also known as Short Tandem Repeats (STRs) are small (1-6 base pairs) repeating stretches of DNA scattered throughout the entire genome and account for approximately 3 % of the human genome. Due to their repeated structure, microsatellites are prone to high mutation rate. Microsatellite instability (MSI) is a unique molecular alteration and hyper-mutable phenotype, which is the result of a defective DNA mismatch repair (MMR) system, and can be defined as the presence of alternate sized repetitive DNA sequences which are not present in the corresponding germ line DNA. The presence of MSI is found in sporadic colon, gastric, sporadic endometrial and the majority of other cancers. Approximately, 15-20 % of colorectal cancers display MSI. Determination of MSI status in CRC has prognostic and therapeutic implications. As well, detecting MSI is used diagnostically for tumor detection and classification. For these reasons, microsatellite instability analysis is becoming more and more important in colorectal cancer patients. The objective of this review is to provide the comprehensive summary of the update knowledge of colorectal cancer classification and diagnostic features of microsatellite instability

Detection of t(8;14) c-myc/IgH gene rearrangement by long-distance polymerase chain reaction in patients with diffuse large B-cell lymphoma

AbstractObjective/backgroundSpecific chromosomal translocations are found in human leukemias and lymphomas. These translocations are closely related to particular histological and immunological phenotypes. In Burkitt’s lymphoma, translocation t(8;14)(q24;q32), which involves the c-myc gene (8q24) and the immunoglobulin heavy-chain (IgH) locus (14q32), accounts for 90–95% of all chromosomal translocations. This translocation can be found in 2–5% of diffuse large B-cell lymphoma (DLBCL). Long-distance polymerase chain reaction (LD-PCR) assays, which can identify oncogene/Ig gene rearrangement, can detect these fusion genes. The objective of this study was to detect t(8;14) c-myc/IgH gene rearrangement by LD-PCR in patients with DLBCL.MethodsIn this study, 54 DLBCL cases were tested by LD-PCR with specific primers. LD-PCR was used for two breakpoints in both the IgH gene (joining region and γ switch region) and the myc gene (Exons 2 and 3).ResultsAs much as 1.85% of the samples were positive for the γ constant region and Exon 2 of the myc gene.ConclusionLD-PCR can be used for the detection of t(8;14) c-myc/IgH gene rearrangement in patients with DLBCL

Analysis of Methylation and Expression Profile of Foxp3 Gene in Patients with Behçet’s Syndrome

Forkhead box P3 (Foxp3) gene is an important means in the Treg cells function, in both maintenances of immune tolerance and regulation of response. Epigenetic modifications of the foxp3 gene at its regulatory regions control the chromatin accessibility for the transcription factors and other transcriptional regulators in order to control Foxp3 expression. In addition, the methylation status of CpG islands within the Foxp3 promoter and regulatory elements regulate the expression of Foxp3. This study was performed to assess the role of the foxp3 gene in patients with Behçet’s syndrome (BS). Venous blood samples were collected from all participants and peripheral blood mononuclear cells (PBMC) were extracted through Ficoll-Hypaque method. Genomic DNA was randomly sheared by sonication and immunoprecipitated with a monoclonal antibody. The status methylation of the foxp3 gene was estimated in 108 blood samples of active BS patients and healthy individuals (controls); using methylation DNA immunoprecipitation (MeDIP) technique. Expression analysis was carried out; using Real-time PCR. The expression of foxp3 gene in the patients' group (mean±SD: 1.79±1.12) was significantly lower than the healthy group (mean±SD: 2.73±1.33) (p<001). Also, the methylation levels of Foxp3 promoter showed that its level in patients (mean±SD: 2.3±1.16) was higher than the healthy group (mean±SD: 1.85±0.59). However, this increase was not statistically significant (p>0.05). Also, these results indicated that increasing the amount of methylation of the foxp3 gene by reducing its expression leads to an increase and intensifying of the disease. The decrease in Foxp3 expression is possibly associated with hypermethylation of the gene, and it can be considered as a risk factor for BS. Future studies may be needed to identify the capability of specific DNA methylation alterations in this syndrome

Evaluation of microsatellite instability in tumor and tumor marginal samples of sporadic colorectal cancer using mononucleotide markers

Microsatellite instability (MSI) is a unique molecular alteration that is due to a defective DNA mismatch repair (MMR) system. Approximately, 15-20 % of sporadic colorectal cancers (CRC) display MSI. Determination of MSI status in CRC has prognostic and predictive implications. Additionally, detecting MSI is used diagnostically for tumor detection and classification. The present study analyzed a panel of five mononucleotide markers, BAT- 25, BAT-26, NR-21, NR-22 and NR-27, amplified in a single multiplex PCR reaction to evaluate MSI status in CRC patients. Genomic DNA from 50 CRC and paired adjacent normal tissues was used for PCR-based MSI analysis. Our finding showed microsatellite instability in 36 % of specimens. Instability with differences in allele lengths was observed in the tumoral DNA compared to the tumor-free margin DNA sample. The frequency of instability in NR-21, BAT-26 and BAT-25 markers were more than others; their frequency were 35.48 %, 29.03 %, and 22.58 %, respectively. In conclusion, the NR-21, BAT-26, and BAT-25 were the most useful markers for discriminating cancer tissue from normal, therefore these markers have demonstrated promising potential for determining MSI status in patients with sporadic colorectal cancer

Differentially expressed alternatively spliced genes in Malignant Pleural Mesothelioma identified using massively parallel transcriptome sequencing

<p>Abstract</p> <p>Background</p> <p>Analyses of Expressed Sequence Tags (ESTs) databases suggest that most human genes have multiple alternative splice variants. The alternative splicing of pre-mRNA is tightly regulated during development and in different tissue types. Changes in splicing patterns have been described in disease states. Recently, we used whole-transcriptome shotgun pryrosequencing to characterize 4 malignant pleural mesothelioma (MPM) tumors, 1 lung adenocarcinoma and 1 normal lung. We hypothesized that alternative splicing profiles might be detected in the sequencing data for the expressed genes in these samples.</p> <p>Methods</p> <p>We developed a software pipeline to map the transcriptome read sequences of the 4 MPM samples and 1 normal lung sample onto known exon junction sequences in the comprehensive AceView database of expressed sequences and to count how many reads map to each junction. 13,274,187 transcriptome reads generated by the Roche/454 sequencing platform for 5 samples were compared with 151,486 exon junctions from the AceView database. The exon junction expression index (EJEI) was calculated for each exon junction in each sample to measure the differential expression of alternative splicing events. Top ten exon junctions with the largest EJEI difference between the 4 mesothelioma and the normal lung sample were then examined for differential expression using Quantitative Real Time PCR (qRT-PCR) in the 5 sequenced samples. Two of the differentially expressed exon junctions (ACTG2.aAug05 and CDK4.aAug05) were further examined with qRT-PCR in additional 18 MPM and 18 normal lung specimens.</p> <p>Results</p> <p>We found 70,953 exon junctions covered by at least one sequence read in at least one of the 5 samples. All 10 identified most differentially expressed exon junctions were validated as present by RT-PCR, and 8 were differentially expressed exactly as predicted by the sequence analysis. The differential expression of the AceView exon junctions for the ACTG2 and CDK4 genes were also observed to be statistically significant in an additional 18 MPM and 18 normal lung samples examined using qRT-PCR. The differential expression of these two junctions was shown to successfully classify these mesothelioma and normal lung specimens with high sensitivity (89% and 78%, respectively).</p> <p>Conclusion</p> <p>Whole-transcriptome shotgun sequencing, combined with a downstream bioinformatics pipeline, provides powerful tools for the identification of differentially expressed exon junctions resulting from alternative splice variants. The alternatively spliced genes discovered in the study could serve as useful diagnostic markers as well as potential therapeutic targets for MPM.</p

microRNA profiling in Epstein–Barr virus-associated B-cell lymphoma

The Epstein–Barr virus (EBV) is an oncogenic human Herpes virus found in ∼15% of diffuse large B-cell lymphoma (DLBCL). EBV encodes miRNAs and induces changes in the cellular miRNA profile of infected cells. MiRNAs are small, non-coding RNAs of ∼19–26 nt which suppress protein synthesis by inducing translational arrest or mRNA degradation. Here, we report a comprehensive miRNA-profiling study and show that hsa-miR-424, -223, -199a-3p, -199a-5p, -27b, -378, -26b, -23a, -23b were upregulated and hsa-miR-155, -20b, -221, -151-3p, -222, -29b/c, -106a were downregulated more than 2-fold due to EBV-infection of DLBCL. All known EBV miRNAs with the exception of the BHRF1 cluster as well as EBV-miR-BART15 and -20 were present. A computational analysis indicated potential targets such as c-MYB, LATS2, c-SKI and SIAH1. We show that c-MYB is targeted by miR-155 and miR-424, that the tumor suppressor SIAH1 is targeted by miR-424, and that c-SKI is potentially regulated by miR-155. Downregulation of SIAH1 protein in DLBCL was demonstrated by immunohistochemistry. The inhibition of SIAH1 is in line with the notion that EBV impedes various pro-apoptotic pathways during tumorigenesis. The down-modulation of the oncogenic c-MYB protein, although counter-intuitive, might be explained by its tight regulation in developmental processes

Therapeutic Effects of Myeloid Cell Leukemia-1 siRNA on Human Acute Myeloid Leukemia Cells

Purpose: Up-regulation of Mcl-1, a known anti-apoptotic protein, is associated with the survival and progression of various malignancies including leukemia. The aim of this study was to explore the effect of Mcl-1 small interference RNA (siRNA) on the proliferation and apoptosis of HL-60 acute myeloid leukemia (AML) cells. Methods: siRNA transfection was performed using Lipofectamine™2000 reagent. Relative mRNA and protein expressions were quantified by quantitative real-time PCR and Western blotting, respectively. Trypan blue assay was performed to assess tumor cell proliferation after siRNA transfection. The cytotoxic effect of Mcl-1 siRNA on leukemic cells was measured using MTT assay. Apoptosis was detected using ELISA cell death assay. Results: Mcl-1 siRNA clearly lowered both Mcl-1 mRNA and protein levels in a time-dependent manner, leading to marked inhibition of cell survival and proliferation. Furthermore, Mcl-1 down-regulation significantly enhanced the extent of HL-60 apoptotic cells. Conclusion: Our results suggest that the down-regulation of Mcl-1 by siRNA can effectively trigger apoptosis and inhibit the proliferation of leukemic cells. Therefore, Mcl-1 siRNA may be a potent adjuvant in AML therapy