Alterations in the gene expression of organs in contact with the environment may signal exposure to toxins. To identify genes in lung tissue whose expression levels are altered by cigarette smoking, we compared the transcriptomes of lung tissue between 118 ever smokers and 58 never smokers. In all cases, the tissue studied was non-involved lung tissue obtained at lobectomy from patients with lung adenocarcinoma. Of the 17,097 genes analyzed, 357 were differentially expressed between ever smokers and never smokers (FDR < 0.05), including 290 genes that were up-regulated and 67 down-regulated in ever smokers. For 85 genes, the absolute value of the fold change was ≥2. The gene with the smallest FDR was MYO1A (FDR = 6.9 × 10−4) while the gene with the largest difference between groups was FGG (fold change = 31.60). Overall, 100 of the genes identified in this study (38.6%) had previously been found to associate with smoking in at least one of four previously reported datasets of non-involved lung tissue. Seven genes (KMO, CD1A, SPINK5, TREM2, CYBB, DNASE2B, FGG) were differentially expressed between ever and never smokers in all five datasets, with concordant higher expression in ever smokers. Smoking-induced up-regulation of six of these genes was also observed in a transcription dataset from lung tissue of non-cancer patients. Among the three most significant gene networks, two are involved in immunity and inflammation and one in cell death. Overall, this study shows that the lung parenchyma transcriptome of smokers has altered gene expression and that these alterations are reproducible in different series of smokers across countries. Moreover, this study identified a seven-gene panel that reflects lung tissue exposure to cigarette smoke.
Many single nucleotide polymorphisms (SNPs) have been associated with lung cancer but lack confirmation and functional characterization. We retested the association of 56 candidate SNPs with lung adenocarcinoma risk and overall survival in a cohort of 823 Italian patients and 779 healthy controls, and assessed their function as expression quantitative trait loci (eQTLs). In the replication study, eight SNPs (rs401681, rs3019885, rs732765, rs2568494, rs16969968, rs6495309, rs11634351, and rs4105144) associated with lung adenocarcinoma risk and three (rs9557635, rs4105144, and rs735482) associated with survival. Five of these SNPs acted as cis-eQTLs, being associated with the transcription of IREB2 (rs2568494, rs16969968, rs11634351, rs6495309), PSMA4 (rs6495309) and ERCC1 (rs735482), out of 10,821 genes analyzed in lung. For these three genes, we obtained experimental evidence of differential allelic expression in lung tissue, pointing to the existence of in-cis genomic variants that regulate their transcription. These results suggest that these SNPs exert their effects on cancer risk/outcome through the modulation of mRNA levels of their target genes.The study of genetic factors modulating an individual's predisposition to lung cancer is supported by strong epidemiological evidence obtained from various types of studies. Observational studies have consistently reported an increased risk of lung cancer in first-degree relatives of lung cancer patients 1-5 . Genome-wide association studies (GWAS) on population-based series identified three main susceptibility loci, at 5p15 6-8 , 6p21 6 , and 15q25. The locus at 15q25 harbors genes for three nicotinic acetylcholine receptor subunits (CHRNA3, CHRNA5, and CHRNB4) that have previously been associated with lung cancer risk and nicotine dependence 6,9,10 . Other GWAS found many single nucleotide polymorphisms (SNPs) that associated with lung cancer risk [11][12][13][14][15][16] . However, the results obtained in these studies have not generally been confirmed, even in a large consortium study 17 .Some genetic variants associated with lung cancer risk have also been associated with prognosis. For instance, a polymorphism (rs6495309) in the promoter of CHRNA3 gene has been reported to be associated with the overall survival of patients with early-stage non-small-cell lung cancer (NSCLC) 18 . Moreover, rs667282 in CHRNA5 has recently been proposed as a modifier of prognosis in advanced NSCLC 19 . Several other SNPs, found using a GWAS approach, were proposed to be associated with prognosis or survival of lung cancer patients in different populations [20][21][22][23] . However, these studies did not identify the same candidate polymorphisms, which may be due (at least in part) to the wide genetic heterogeneity of the human population.The GWAS cited here, which aimed to find SNPs associated with lung cancer risk or prognosis, identified mostly non-overlapping subsets of SNPs, hindering progress in lung cancer research. One limitation of these studies is that they investigate...
Introduction Atypical hemolytic uremic syndrome (aHUS) is mainly due to complement regulatory gene abnormalities with a dominant pattern but incomplete penetrance. Thus, healthy carriers can be identified in any family of aHUS patients, but it is unpredictable if they will eventually develop aHUS. Methods Patients are screened for 10 complement regulatory gene abnormalities and once a genetic alteration is identified, the search is extended to at-risk family members. The present cohort study includes 257 subjects from 71 families: 99 aHUS patients (71 index cases + 28 affected family members) and 158 healthy relatives with a documented complement gene abnormality. Results Fourteen families (19.7%) experienced multiple cases. Over a cumulative observation period of 7595 person-years, only 28 family members carrying gene mutations experienced aHUS (overall penetrance of 20%), leading to a disease rate of 3.69 events for 1000 person-years. The disease rate was 7.47 per 1000 person-years among siblings, 6.29 among offspring, 2.01 among parents, 1.84 among carriers of variants of uncertain significance, and 4.43 among carriers of causative variants. Conclusions The penetrance of aHUS seems a lot lower than previously reported. Moreover, the disease risk is higher in carriers of causative variants and is not equally distributed among generations: siblings and the offspring of patients have a much greater disease risk than parents. However, risk calculation may depend on variant classification that could change over time.
Read-through transcripts result from the continuous transcription of adjacent, similarly oriented genes, with the splicing out of the intergenic region. They have been found in several neoplastic and normal tissues, but their pathophysiological significance is unclear. We used high-throughput sequencing of cDNA fragments (RNA-Seq) to identify read-through transcripts in the non-involved lung tissue of 64 surgically treated lung adenocarcinoma patients. A total of 52 distinct read-through species was identified, with 24 patients having at least one read-through event, up to a maximum of 17 such transcripts in one patient. Sanger sequencing validated 28 of these transcripts and identified an additional 15, for a total of 43 distinct read-through events involving 35 gene pairs. Expression levels of 10 validated read-through transcripts were measured by quantitative PCR in pairs of matched non-involved lung tissue and lung adenocarcinoma tissue from 45 patients. Higher expression levels were observed in normal lung tissue than in the tumor counterpart, with median relative quantification ratios between normal and tumor varying from 1.90 to 7.78; the difference was statistically significant (P < 0.001, Wilcoxon's signed-rank test for paired samples) for eight transcripts: ELAVL1–TIMM44, FAM162B–ZUFSP, IFNAR2–IL10RB, INMT–FAM188B, KIAA1841–C2orf74, NFATC3–PLA2G15, SIRPB1–SIRPD, and SHANK3–ACR. This report documents the presence of read-through transcripts in apparently normal lung tissue, with inter-individual differences in patterns and abundance. It also shows their down-regulation in tumors, suggesting that these chimeric transcripts may function as tumor suppressors in lung tissue.
Background and purpose Salvage therapies for urothelial carcinoma are needed. A single-arm trial in patients with advanced or metastatic urothelial carcinoma refractive to other therapies found that alisertib, a selective inhibitor of aurora kinase A, maintained stable disease in a few cases, despite a low objective response rate. To better understand why some patients benefited from alisertib, we genotyped the 22 patients of this pilot trial for two single nucleotide polymorphisms (rs2273535 and rs1047972) in AURKA, the gene encoding aurora kinase A, and looked for associations with survival and treatment response. Results Carrier status for the minor allele of rs2273535 (T91A, p. F31I) was a favorable prognostic factor for progression-free survival (HR = 0.18; 95% CI, 0.039-0.81; P = 0.026) but not for overall survival (HR = 0.88; 95% CI, 0.26-2.9; P = 0.83). These results were confirmed in multivariable analyses, adjusting for sex, age and hemoglobin, for both progression-free survival (HR = 0.11; 95% CI, 0.018-0.69; P = 0.018) and overall survival. No association was found between rs1047972 and survival. Moreover, neither SNP was associated with treatment response. Conclusion In patients who received alisertib for advanced or metastatic urothelial carcinoma, longer progression-free survival was observed in carriers of the minor allele A of rs2273535 in AURKA than in patients who were homozygous for the major allele T. This finding, based on a small pilot trial, warrants further investigation.
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