Identifying novel biomarkers of gastric cancer through integration analysis of single nucleotide polymorphisms and gene expression profile
INTERNATIONAL JOURNAL OF BIOLOGICAL MARKERS
Authors: Wang, Tao; Xu, Yan; Hou, Peng
Abstract
Purpose: Single nucleotide polymorphisms (SNPs) are an important cause of functional variation in proteins leading to tumorigenesis. We aimed to identify candidate biomarkers with polymorphisms in gastric cancer (GC). Methods: The SNP microarray profile GSE29996 including 50 GC samples and 50 normal controls, and gene expression data GSE56807 consisting of 5 GC samples and 5 controls were downloaded from the Gene Expression Omnibus database. After preprocessing of raw data, GC-associated SNPs were identified using the Cochran-Armitage trend test, and differentially expressed genes (DEGs) were screened out using the limma package in R. Significant DEGs with risk associated SNP loci were screened using the Fisher combination test. Gene ontology function and pathway enrichment analyses were performed for DEGs with risk associated SNP loci by GenCLip online tool. Transcriptional regulatory analysis was also conducted for transcription factor and target DEGs. Results: A total of 79 DEGs with risk associated SNP loci were identified from GC samples compared with normal controls. These DEGs were mainly enriched in anatomical structure development, including embryo development. Additionally, DEGs were significantly involved in the NO1 pathway, including actin, alpha 1, skeletal muscle (ACTA1). In the regulatory network, transcription factor forkhead box L1 (FOXL1) regulated 26 DEGs with risk associated SNP loci, including Iroquois homeobox 1 (IRX1) rs11134044, sex determining region Y (SRY)-box1 (SOX1) rs9549447 and msh homeobox 1 (MSX1) rs41451149. Conclusions: IRX1, SOX1 and MSX1 with risk associated SNP loci may serve as candidate biomarkers for diagnosis and prognosis of GC.
Duplication events downstream of IRX1 cause North Carolina macular dystrophy at the MCDR3 locus
SCIENTIFIC REPORTS
Authors: Cipriani, Valentina; Silva, Raquel S.; Arno, Gavin; Pontikos, Nikolas; Kalhoro, Ambreen; Valeina, Sandra; Inashkina, Inna; Audere, Mareta; Rutka, Katrina; Puech, Bernard; Michaelides, Michel; van Heyningen, Veronica; Lace, Baiba; Webster, Andrew R.; Moore, Anthony T.
Abstract
Autosomal dominant North Carolina macular dystrophy (NCMD) is believed to represent a failure of macular development. The disorder has been linked to two loci, MCDR1 (chromosome 6q16) and MCDR3 (chromosome 5p15-p13). Recently, non-coding variants upstream of PRDM13 (MCDR1) and a duplication including IRX1 (MCDR3) have been identified. However, the underlying disease-causing mechanism remains uncertain. Through a combination of sequencing studies on eighteen NCMD families, we report two novel overlapping duplications at the MCDR3 locus, in a gene desert downstream of IRX1 and upstream of ADAMTS16. One duplication of 43 kb was identified in nine families (with evidence for a shared ancestral haplotype), and another one of 45 kb was found in a single family. Three families carry the previously reported V2 variant (MCDR1), while five remain unsolved. The MCDR3 locus is thus refined to a shared region of 39 kb that contains DNAse hypersensitive sites active at a restricted time window during retinal development. Publicly available data confirmed expression of IRX1 and ADAMTS16 in human fetal retina, with IRX1 preferentially expressed in fetal macula. These findings represent a major advance in our understanding of the molecular genetics of NCMD and provide insights into the genetic pathways involved in human macular development.