DNA methylation mapping identifies gene regulatory effects in patients with systemic lupus erythematosus
ANNALS OF THE RHEUMATIC DISEASES
Authors: Imgenberg-Kreuz, Juliana; Almlof, Jonas Carlsson; Leonard, Dag; Alexsson, Andrei; Nordmark, Gunnel; Eloranta, Maija-Leena; Rantapaa-Dahlqvist, Solbritt; Bengtsson, Anders A.; Jonsen, Andreas; Padyukov, Leonid; Gunnarsson, Iva; Svenungsson, Elisabet; Sjowall, Christopher; Ronnblom, Lars; Syvanen, Ann-Christine; Sandling, Johanna K.
Abstract
Objectives Systemic lupus erythematosus (SLE) is a chronic autoimmune condition with heterogeneous presentation and complex aetiology where DNA methylation changes are emerging as a contributing factor. In order to discover novel epigenetic associations and investigate their relationship to genetic risk for SLE, we analysed DNA methylation profiles in a large collection of patients with SLE and healthy individuals. Methods DNA extracted from blood from 548 patients with SLE and 587 healthy controls were analysed on the Illumina HumanMethylation 450 k BeadChip, which targets 485 000 CpG sites across the genome. Single nucleotide polymorphism (SNP) genotype data for 196 524 SNPs on the Illumina ImmunoChip from the same individuals were utilised for methylation quantitative trait loci (cis-meQTLs) analyses. Results We identified and replicated differentially methylated CpGs (DMCs) in SLE at 7245 CpG sites in the genome. The largest methylation differences were observed at type I interferon-regulated genes which exhibited decreased methylation in SLE. We mapped cis-meQTLs and identified genetic regulation of methylation levels at 466 of the DMCs in SLE. The meQTLs for DMCs in SLE were enriched for genetic association to SLE, and included seven SLE genome-wide association study (GWAS) loci: PTPRC (CD45), MHC-class III, UHRF1BP1, IRF5, IRF7, IKZF3 and UBE2L3. In addition, we observed association between genotype and variance of methylation at 20 DMCs in SLE, including at the HLADQB2 locus. Conclusions Our results suggest that several of the genetic risk variants for SLE may exert their influence on the phenotype through alteration of DNA methylation levels at regulatory regions of target genes.
Prognostication of a 13-immune-related-gene signature in patients with early triple-negative breast cancer
BREAST CANCER RESEARCH AND TREATMENT
Authors: Kim, Ji-Yeon; Jung, Hae Hyun; Sohn, Insuk; Woo, Sook Young; Cho, Hyun; Cho, Eun Yoon; Lee, Jeong Eon; Kim, Seok Won; Nam, Seok Jin; Park, Yeon Hee; Ahn, Jin Seok; Im, Young-Hyuck
Abstract
Purpose We investigated the expression profiles of immune genes in patients with triple-negative breast cancer (TNBC) to identify the prognostic value of immune genes and their clinical implications. Methods NanoString nCounter Analysis of 770 immune-related genes was used to measure immune gene expression in patients with TNBC who underwent curative surgery followed by adjuvant chemotherapy at Samsung Medical Center between 2000 and 2004. Statistical analyses were conducted to identify the associations between gene expression and distant recurrence-free survival (DRFS). Results Of 1189 patients who underwent curative BC surgery, 200 TNBC patients were included and stage was the only clinical factor predictive of DRFS. In terms of immune genes, 155 of 770 genes were associated with DRFS (p < 0.01). Further multivariate analysis revealed that 13 genes,CD1B,CD53,CT45A1,GTF3C1,IL11RA,IL1RN,LRRN3,MAPK1,NEFL,PRKCE,PTPRC,SPACA3andTNFSF11, were associated with patient prognosis (p < 0.05). The prognostic value of stage and expression levels of 13 immune genes was analyzed and the area under the receiver operating characteristic curve (AUC) was 0.923. Based on the AUC, we divided patients into three genetic risk groups and DRFS rate was significantly different according to genetic risk groups, even in the same stage (p < 0.001). Conclusions In this study, a 13-gene expression profile in combination with stage precisely predicted distant recurrence of early TNBC. Therefore, this 13-immune-gene signature could help predict TNBC prognosis and provide guidance for treatment as well as the opportunity to develop new targets for immunotherapy in TNBC patients.