The conservation (PhastCons and GERP) scores are from Exome Variant Server

The conservation (PhastCons and GERP) scores are from Exome Variant Server. == Implications of the miR-TS-SNPs in various cancer types and pharmacogenomics == The high-confidence miR-TS-SNPs predicted to deregulate the expression of proto-oncogenes represent a source of reliable candidates. cancer patients. Therefore, we developed a systematic computational pipeline that integrates data from well-established databases, followed stringent selection criteria and identified a Ezatiostat 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 Ezatiostat altogether these SNPs occur in proto-oncogenes enriched for kinase activities. We provide detailedin silicoevidence for the functional effect of these candidate SNPs in various types of cancer. == Introduction == Cancer is a complexgenetic disease that arises due to structural, functional, and expression abnormalities in two main categories of genes, namely tumor suppressors and oncogenes, which show loss-of-function and gain-of-function, respectively. Proto-oncogenes, the normal cellular genes involved in cell proliferation and differentiation can be activated into cancer-promoting oncogenes by mutation, DNA amplification, or increased expression (Torry and Cooper,1991). Apart from these classical mechanisms, a recent mode of oncogenic transformation occurs through loss of microRNA binding sites caused either by translocation of 3untranslated region (3UTR) or by use of alternative polyadenylation signals that shortens the 3UTR (Mayr and Bartel,2009; Mayr et al.,2007). MicroRNAs (miRNAs) are short (22 nt) endogenous noncoding RNAs derived by nuclear and cytoplasmic processing of longer RNA transcripts, and they regulate gene expression by binding to complementary sequencesmiRNA target sitespresent mostly in the 3UTR of mRNAs (Bartel,2004). In mammals, this binding is mediated usually through nucleotides spanning the position 2 to 7 at the 5 end of miRNAs (called miR-seed) to their target sequence by Watson-Crick base pairing, leading to translational inhibition or very rarely mRNA cleavage (Lai,2002; Lewis et al.,2003). Recent studies have demonstrated that a single nucleotide mismatch between miR-seed and its target site can abolish repression (Brennecke et al.,2005), thus establishing the requirement of stringent recognition between the two interacting sequences. Therefore, naturally occurring genetic variants or other genetic lesions at miRNA target sites can alter the efficacy and thermodynamics of miRNA binding and can significantly affect gene expression, leading to cancer and other diseases (Nicoloso et al.,2010; Ryan et al.,2010). Single Nucleotide Polymorphisms (SNPs) are the most abundant form of genetic variation (90%), occurring once every several hundred base pairs throughout Ezatiostat the human genome (Cargill et al.,1999). By definition, a SNP is a genomic locus where two or more alternative bases occur with an appreciable frequency of >1%. Our understanding of the contribution of SNPs to diversity among individuals, phenotypes, traits, and diseases has greatly been enhanced by several landmark studies (Altshuler et al.,2010; Shastry,2009; Thorisson and Stein,2003; 1000 Genomes Project Consortium,2010). Interestingly, results of The ENCODE Project Consortium illustrate that disease-associated SNPs are enriched within noncoding yet functional DNA elements (Bernstein et al.,2012). SNPs in coding regions of the genome can alter protein conformation or function as elucidated by a number of functional (Megaraj et al.,2011; Ueki et al.,2010), as well as molecular dynamic simulation studies (Huang et al.,2010; Kumar et al.,2013; Rajendran Rabbit Polyclonal to PEX10 et al.,2012), while those in noncoding regions can impair regulation of gene expression (Haraksingh Ezatiostat et al.,2013). To this end, SNPs occurring in miRNA target sites (miR-TS-SNPs) need special attention, as there is a rapid expansion of literature associating miRNAs (Vandenboom Ii et al.,2008) and miR-TS-SNPs (Landi et al.,2008; Manikandan et al.,2012; Saunders et al.,2007; Yu et al.,2007) to cancer progression and susceptibility. Given the wealth of data and sequence information that is currently available on the human genome, it is possible to locate genetic variations in miRNA target sites. Hence, using an integrative and systematic computational approach, we identified a panel of high.