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Author(s): R Spanagel; G Pendyala; C Abarca; T Zghoul; C Sanchis-Segura; M C Magnone; J Lascorz; M Depner; D Holzberg; M Soyka; S Schreiber; F Matsuda; M Lathrop; G Schumann; [...]

OBJECTIVE: Single-nucleotide polymorphisms (SNPs) of the tumor necrosis factor gene TNF at positions -238 and -308 have been associated with psoriasis vulgaris and psoriatic arthritis (PsA). The strong linkage disequilibrium (LD) at chromosome region 6p21, a region known to harbor risk factors for psoriasis susceptibility (PSORS1) other than just SNPs of the TNF gene, renders the interpretation of these findings difficult. The aim of this study was to analyze several SNPs of the TNF gene and its neighboring LTA gene for independent and dependent carriage of the PSORS1 risk allele. METHODS: SNPs in the promoter of the TNF (-238G/A, -308G/A, -857C/T, and -1031T/C), LTA (+252A/G), TNLFRSF1A (+36A/G), and TNLFRSF1B (+676T/G) genes were genotyped in 375 psoriasis patients, 375 PsA patients, and 376 controls. The Trp- Trp-Cys-Cys haplotype of the CCHCR1 gene (CCHCR1*WWCC) was used as an estimate of the risk allele PSORS1. RESULTS: Whereas we were able to confirm the previously described strong association of allele TNF*-238A with psoriasis, our study revealed that this association was completely dependent on carriage of the PSORS1 risk allele. For PsA, but not psoriasis vulgaris without joint involvement, a strong association with the allele TNF*-857T (odds ratio 1.956 [95% confidence interval 1.334-2.881]; corrected P = 0.0025) was also detected in patients negative for the PSORS1 risk allele. CONCLUSION: Our results indicate that there are genetic differences between psoriasis vulgaris patients with and without joint manifestations. While the previously reported association between TNF*-238A and psoriasis seems to primarily reflect LD with PSORS1, TNF*-857T may represent a risk factor for PsA that is independent of the PSORS1 allele. [ABSTRACT FROM AUTHOR]

Developing prolonged antigen delivery systems that mimic long-term exposure to pathogens appears as a promising but still poorly explored approach to reach durable immunities. In this study, we have used a simple technology by which His-tagged proteins can be assembled, assisted by divalent cations, as supramolecular complexes with progressive complexity, namely protein-only nanoparticles and microparticles. Microparticles produced out of nanoparticles are biomimetics of secretory granules from the mammalian hormonal system. Upon subcutaneous administration, they slowly disintegrate, acting as an endocrine-like secretory system and rendering the building block nanoparticles progressively bioavailable. The performance of such materials, previously validated for drug delivery in oncology, has been tested here regarding the potential for time-prolonged antigen release. This has been completed by taking, as a building block, a nanostructured version of p30, a main structural immunogen from the African swine fever virus (ASFV). By challenging the system in both mice and pigs, we have observed unusually potent pro-inflammatory activity in porcine macrophages, and long-lasting humoral and cellular responses in vivo, which might overcome the need for an adjuvant. The robustness of both innate and adaptive responses tag, for the first time, these dynamic depot materials as a novel and valuable instrument with transversal applicability in immune stimulation and vaccinology.

By following simple protein engineering steps, recombinant proteins with promising applications in the field of drug delivery can be assembled in the form of functional materials of increasing complexity, either as nanoparticles or nanoparticle-leaking secretory microparticles. Among the suitable strategies for protein assembly, the use of histidine-rich tags in combination with coordinating divalent cations allows the construction of both categories of material out of pure polypeptide samples. Such molecular crosslinking results in chemically homogeneous protein particles with a defined composition, a fact that offers soft regulatory routes towards clinical applications for nanostructured protein-only drugs or for protein-based drug vehicles. Successes in the fabrication and final performance of these materials are expected, irrespective of the protein source. However, this fact has not yet been fully explored and confirmed. By taking the antigenic RBD domain of the SARS-CoV-2 spike glycoprotein as a model building block, we investigated the production of nanoparticles and secretory microparticles out of the versions of recombinant RBD produced by bacteria ( Escherichia coli ), insect cells (Sf9), and two different mammalian cell lines (namely HEK 293F and Expi293F). Although both functional nanoparticles and secretory microparticles were effectively generated in all cases, the technological and biological idiosyncrasy of each type of cell factory impacted the biophysical properties of the products. Therefore, the selection of a protein biofabrication platform is not irrelevant but instead is a significant factor in the upstream pipeline of protein assembly into supramolecular, complex, and functional materials.

Post-translational modification by Small Ubiquitin-like Modifier (SUMO) proteins regulates numerous cellular processes. This modification involves the covalent and reversible attachment of SUMO to target proteins through an isopeptide bond, using a cascade of E1, E2 and E3 SUMOylation enzymes. Most functions of SUMO depend on the establishment of non-covalent protein-protein interactions between SUMOylated substrates and their binding partners. The vast majority of these interactions involve a conserved surface in the SUMO protein and a SUMO interacting motif (SIM), a short stretch of hydrophobic amino acids and an acidic region, in the interactor protein. Despite single SUMO-SIM interactions are relatively weak, they can have a huge impact at different levels, altering the activity, localization and stability of proteins, triggering the formation of macromolecular assemblies or inducing phase separation. Moreover, SUMO-SIM interactions are ubiquitous in most enzymes of the SUMO pathway, and play essential roles in SUMO conjugation and deconjugation. Here, we analyze the role of SUMO-SIM contacts in SUMO enzymes and targets and discuss how this humble interaction participates in SUMOylation reactions and mediates the outcome of this essential post-translational modification., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Post-translational modification of proteins by ubiquitin and ubiquitin-like modifiers, such as SUMO, are key events in protein homeostasis or DNA damage response. Smc5/6 is a nuclear multi-subunit complex that participates in the recombinational DNA repair processes and is required in the maintenance of chromosome integrity. Nse2 is a subunit of the Smc5/6 complex that possesses SUMO E3 ligase activity by the presence of a SP-RING domain that activates the E2~SUMO thioester for discharge on the substrate. Here we present the crystal structure of the SUMO E3 ligase Nse2 in complex with an E2-SUMO thioester mimetic. In addition to the interface between the SP-RING domain and the E2, the complex reveals how two SIM (SUMO-Interacting Motif) -like motifs in Nse2 are restructured upon binding the donor and E2-backside SUMO during the E3-dependent discharge reaction. Both SIM interfaces are essential in the activity of Nse2 and are required to cope with DNA damage., (© 2021. The Author(s).)

The small ubiquitin-like modifier (SUMO) is a post-translational modifier that can regulate the function of hundreds of proteins inside the cell. SUMO belongs to the ubiquitin-like family of proteins that can be attached to target proteins by a dedicated enzymatic cascade pathway formed by E1, E2 and E3 enzymes. SUMOylation is involved in many cellular pathways, having in most instances essential roles for their correct function. In this review, we want to highlight the latest research on the molecular mechanisms that lead to the formation of the isopeptidic bond between the lysine substrate and the C-terminus of SUMO. In particular, we will focus on the recent discoveries on the catalytic function of the SUMO E3 ligases revealed by structural and biochemical approaches. Also, we will discuss important questions regarding specificity in SUMO conjugation, which it still remains as a major issue due to the small number of SUMO E3 ligases discovered so far, in contrast with the large number of SUMO conjugated proteins in the cell., (© 2019 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

The aggregation propensity of each particular protein seems to be shaped by evolution according to its natural abundance in the cell. The production and downstream processing of recombinant polypeptides implies attaining concentrations that are orders of magnitude above their natural levels, often resulting in their aggregation; a phenomenon that precludes the marketing of many globular proteins for biomedical or biotechnological applications. Therefore, there is a huge interest in methods aimed to increase the proteins solubility above their natural limits. Here, we demonstrate that an updated version of our AGGRESCAN 3D structural aggregation predictor, that now takes into account protein stability, allows for designing mutations at specific positions in the structure that improve the solubility of proteins without compromising their conformation. Using this approach, we have designed a highly soluble variant of the green fluorescent protein and a human single-domain VH antibody displaying significantly reduced aggregation propensity. Overall, our data indicate that the solubility of unrelated proteins can be easily tuned by in silico-designed nondestabilizing amino acid changes at their surfaces.

Modification of chromosomal proteins by conjugation to SUMO is a key step to cope with DNA damage and to maintain the integrity of the genome. The recruitment of SUMO E3 ligases to chromatin may represent one layer of control on protein sumoylation. However, we currently do not understand how cells upregulate the activity of E3 ligases on chromatin. Here we show that the Nse2 SUMO E3 in the Smc5/6 complex, a critical player during recombinational DNA repair, is directly stimulated by binding to DNA Activation of sumoylation requires the electrostatic interaction between DNA and a positively charged patch in the ARM domain of Smc5, which acts as a DNA sensor that subsequently promotes a stimulatory activation of the E3 activity in Nse2. Specific disruption of the interaction between the ARM of Smc5 and DNA sensitizes cells to DNA damage, indicating that this mechanism contributes to DNA repair. These results reveal a mechanism to enhance a SUMO E3 ligase activity by direct DNA binding and to restrict sumoylation in the vicinity of those Smc5/6-Nse2 molecules engaged on DNA., (© 2018 The Authors.)

Within innate immune signaling pathways, interleukin-1 receptor-associated kinases (IRAKs) fulfill key roles downstream of multiple Toll-like receptors and the interleukin-1 receptor. Although human IRAK4 deficiency was shown to lead to severe immunodeficiency in response to pyogenic bacterial infection during childhood, little is known about the role of human IRAK2. We here identified a non-synonymous IRAK2 variant, rs35060588 (coding R214G), as hypofunctional in terms of NF-κB signaling and Toll-like receptor-mediated cytokine induction. This was due to reduced ubiquitination of TRAF6, a key step in signal transduction. IRAK2 rs35060588 occurs in 3-9% of individuals in different ethnic groups, and our studies suggested a genetic association of rs35060588 with colorectal cancer survival. This for the first time implicates human IRAK2 in a human disease and highlights the R214G IRAK2 variant as a potential novel and broadly applicable biomarker for disease or as a therapeutic intervention point., (© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.)

Genome-wide association studies (GWASs) may help to understand the effects of genetic polymorphisms on breast cancer (BC) progression and survival. However, they give only a focused view, which cannot capture the tremendous complexity of this disease. Therefore, we investigated data from a previously conducted GWAS on BC survival for enriched pathways by different enrichment analysis tools using the two main annotation databases Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The goal was to identify the functional categories (GO terms and KEGG pathways) that are consistently overrepresented in a statistically significant way in the list of genes generated from the single nucleotide polymorphism (SNP) data. The SNPs with allelic p-value cut-offs 0.005 and 0.01 were annotated to the genes by excluding or including a 20 kb up-and down-stream sequence of the genes and analyzed by six different tools. We identified eleven consistently enriched categories, the most significant ones relating to cell adhesion and calcium ion binding. Moreover, we investigated the similarity between our GWAS and the enrichment analyses of twelve published gene expression signatures for breast cancer prognosis. Five of them were commonly used and commercially available, five were based on different aspects of metastasis formation and two were developed from meta-analyses of published prognostic signatures. This comparison revealed similarities between our GWAS data and the general and the specific brain metastasis gene signatures as well as the Oncotype DX signature. As metastasis formation is a strong indicator of a patient's prognosis, this result reflects the survival aspect of the conducted GWAS and supports cell adhesion and calcium signaling as important pathways in cancer progression.

Toll-like receptors (TLR) are overexpressed on many types of cancer cells, including colorectal cancer cells, but little is known about the functional relevance of these immune regulatory molecules in malignant settings. Here, we report frequent single-nucleotide polymorphisms (SNP) in the flagellin receptor TLR5 and the TLR downstream effector molecules MyD88 and TIRAP that are associated with altered survival in a large cohort of Caucasian patients with colorectal cancer (n = 613). MYD88 rs4988453, a SNP that maps to a promoter region shared with the acetyl coenzyme-A acyl-transferase-1 (ACAA1), was associated with decreased survival of patients with colorectal cancer and altered transcriptional activity of the proximal genes. In the TLR5 gene, rs5744174/F616L was associated with increased survival, whereas rs2072493/N592S was associated with decreased survival. Both rs2072493/N592S and rs5744174/F616L modulated TLR5 signaling in response to flagellin or to different commensal and pathogenic intestinal bacteria. Notably, we observed a reduction in flagellin-induced p38 phosphorylation, CD62L shedding, and elevated expression of interleukin (IL)-6 and IL-1β mRNA in human primary immune cells from TLR5 616LL homozygote carriers, as compared with 616FF carriers. This finding suggested that the well-documented effect of cytokines like IL-6 on colorectal cancer progression might be mediated by TLR5 genotype-dependent flagellin sensing. Our results establish an important link between TLR signaling and human colorectal cancer with relevance for biomarker and therapy development., (©2013 AACR.)

Inflammatory responses play a vital role at different stages of colorectal carcinogenesis. C-type lectins mediate inflammatory/immune responses and participate in immune escape of pathogens and tumors. Our study aimed to evaluate the correlation between polymorphisms in three C-type lectin genes, CD209, MBL2 and REG4, and colorectal cancer (CRC) risk and clinical outcome. We genotyped 15 potentially functional single nucleotide polymorphisms (SNPs) and assessed their associations with CRC risk in a case-control study of 1353 CRC cases and 767 healthy controls from the Czech Republic. We also analyzed these SNPs in relation to overall and event-free survival in 414 patients. Two CD209 SNPs were associated with CRC risk after adjustment for multiple comparison. Minor allele carriers of the promoter SNP rs2287886 had an increased risk of CRC (OR 1.30, 95% CI 1.08-1.56), while minor allele carriers of the 3'UTR SNP, rs7248637, had a decreased risk (OR 0.74, 95% CI 0.60-0.91). Multivariate survival analyses, including age, gender, TNM stage and grade, showed that patients without distant metastasis at the time of diagnosis and carrying the rs2994809 T allele had a decreased overall and event-free survival (HR 2.11, 95% CI 1.20-3.72 and HR 2.00, 95% CI 1.18-3.39, respectively). We show that SNPs in CD209 may affect CRC risk, while a SNP in REG4 may be a useful marker for CRC progression., (Copyright © 2013 UICC.)

Nasopharyngeal carcinoma (NPC) is a rare malignancy in most parts of the world. It is an Epstein-Barr virus-associated malignancy with an unusual racial and geographical distribution. The host innate immune sensor genes play an important role in infection recognition and immune response against viruses. Therefore, we examined the association between polymorphisms in genes within a group of pattern recognition receptors (including families of Toll-like receptors, C-type lectin receptors, and retinoic acid-inducible gene I-like receptors) and NPC susceptibility. Twenty-six single-nucleotide polymorphisms (SNPs) in five pattern-recognition genes were genotyped in 492 North African NPC cases and 373 frequency-matched controls. TLR3_rs3775291 was the most significantly associated SNP (odds ratio [OR] 1.49; 95% confidence interval [95% CI] 1.11-2.00; P = 0.008; dominant model). The analysis showed also that CD209_rs7248637 (OR 0.69; 95% CI 0.52-0.93; P = 0.02; dominant model) and DDX58_rs56309110 (OR 0.70; 95% CI 0.51-0.98; P = 0.04) were associated with the risk of NPC. An 18% increased risk per allele was observed for the five most significantly associated SNPs, TLR3_rs3775291, CD209_rs7248637, DDX58_rs56309110, CD209_rs4804800, and MBL2_rs10824792, (ptrend = 8.2 × 10(-4)). Our results suggest that genetic variation in pattern-recognition genes is associated with the risk of NPC. These preliminary findings require replication in larger studies.

Colorectal cancer (CRC), one of the most frequent neoplasias worldwide, has both genetic and environmental causes. As yet, however, gene-environment (G × E) interactions in CRC have been studied mostly for a small number of candidate genes only. Therefore, we investigated the possible interaction, in CRC etiology, between single-nucleotide polymorphisms (SNPs) on the one hand, and overweight, smoking and alcohol consumption on the other, at a genome-wide level. To this end, we adopted a two-tiered approach comprising a case-only screening stage I (314 cases) and a case-control validation stage II (259 cases, 1,002 controls). Interactions with the smallest p value in stage I were verified in stage II using multiple logistic regression analysis adjusted for sex and age. In addition, we specifically studied known CRC-associated SNPs for possible G × E interactions. Upon adjustment for sex and age, and after allowing for multiple testing, however, only a single SNP (rs1944511) was found to be involved in a statistically significant interaction, namely with overweight (multiplicity-corrected p = 0.042 in stage II). Several other G × E interactions were nominally significant but failed correction for multiple testing, including a previously reported interaction between rs9929218 and alcohol consumption that also emerged in our candidate SNP study (nominal p = 0.008). Notably, none of the interactions identified in our genome-wide analysis was with a previously reported CRC-associated SNP. Our study therefore highlights the potential of an "agnostic" genome-wide approach to G × E analysis.

Purpose: We identified recently the extracellular matrix (ECM) receptor interaction pathway as a consistently overrepresented category among gene expression profiling studies on colorectal cancer (CRC) prognosis., Methods: Putative regulatory single nucleotide polymorphisms (SNPs) in genes from the ECM pathway were genotyped in 613 CRC patients from Northern Germany (PopGen cohort) and tested for association with disease progression and survival., Results: The eSNP (SNP associated with expression) rs12695175 in CD47 associated with CRC specific survival (HR = 2.18, 95 % CI 1.10-4.33, CC versus AA) and with overall survival (HR = 1.99, 95 % CI 1.04-3.81, CC versus AA). This association remained significant after adjustment for age at diagnosis, tumour stage (T) and lymph node status (N). Three polymorphisms in CD47 were associated with distant metastasis in a dominant model: rs9879947 and rs3206652 in the 3'-UTR (OR = 1.64, 95 % CI 1.01-2.64 and OR = 1.88, 95 % CI 1.27-2.80, respectively) and the eSNP rs3804639 (OR = 1.73, 95 % CI 1.17-2.57)., Conclusions: The novel associations of eSNPs in CD47 with worse survival and distant metastasis should be confirmed by additional studies, since increased expression of this gene has recently been shown to be an indicator of poor prognosis in cancer patients.

Background: Clock genes govern circadian rhythms and shape the effect of alcohol use on the physiological system. Exposure to severe negative life events is related to both heavy drinking and disturbed circadian rhythmicity. The aim of this study was 1) to extend previous findings suggesting an association of a haplotype tagging single nucleotide polymorphism of PER2 gene with drinking patterns, and 2) to examine a possible role for an interaction of this gene with life stress in hazardous drinking., Methods: Data were collected as part of an epidemiological cohort study on the outcome of early risk factors followed since birth. At age 19 years, 268 young adults (126 males, 142 females) were genotyped for PER2 rs56013859 and were administered a 45-day alcohol timeline follow-back interview and the Alcohol Use Disorders Identification Test (AUDIT). Life stress was assessed as the number of severe negative life events during the past four years reported in a questionnaire and validated by interview., Results: Individuals with the minor G allele of rs56013859 were found to be less engaged in alcohol use, drinking at only 72% of the days compared to homozygotes for the major A allele. Moreover, among regular drinkers, a gene x environment interaction emerged (p = .020). While no effects of genotype appeared under conditions of low stress, carriers of the G allele exhibited less hazardous drinking than those homozygous for the A allele when exposed to high stress., Conclusions: These findings may suggest a role of the circadian rhythm gene PER2 in both the drinking patterns of young adults and in moderating the impact of severe life stress on hazardous drinking in experienced alcohol users. However, in light of the likely burden of multiple tests, the nature of the measures used and the nominal evidence of interaction, replication is needed before drawing firm conclusions.

Background: Currently, the TNM classification of malignant tumours based on clinicopathological staging remains the standard for colorectal cancer (CRC) prognostication. Recently, we identified the mitochondrial oxidative phosphorylation chain as a consistently overrepresented category in the published gene expression profiling (GEP) studies on CRC prognosis., Methods: We evaluated associations of putative regulatory single nucleotide polymorphisms (SNPs) in genes from the oxidative phosphorylation chain with survival and disease prognosis in 613 CRC patients from Northern Germany (PopGen cohort)., Results: Two SNPs in the 3' untranslated region of UQCRB (complex III), rs7836698 and rs10504961, were associated with overall survival (HR = 0.52, 95% CI 0.32-0.85 and HR = 0.64, 95% CI 0.42-0.99, for TT carriers). These associations were restricted to the group of patients with cancer located in the colon (HR = 0.42, 95% CI 0.22-0.82 and HR = 0.46, 95% CI 0.25-0.83). Multivariate analysis indicated that both markers might act as independent prognostic markers. Additionally, the TT carriers were ~2 times more likely to develop tumours in the colon than in the rectum. Two SNPs in COX6B1 (complex IV) were associated with lymph node metastasis in a dominant model (rs6510502, OR = 1.75, 95% CI 1.20-2.57; rs10420252, OR = 1.68, 95% CI 1.11-2.53); rs6510502 was associated also with distant metastasis (OR = 1.67, 95% CI 1.09-2.56 in a dominant model)., Conclusions: This is the first report suggesting that markers in genes from the mitochondrial oxidative chain might be prognostic factors for CRC. Additional studies replicating the presented findings are needed.

The 20q13 region is frequently amplified/overexpressed in breast tumours. However, the nature of this amplification/overexpression is unknown. Here, we investigated genetic variation in five 20q13 amplicon genes (MYBL2, AURKA, ZNF217, STK4 and PTPN1) and its impact on breast cancer (BC) susceptibility and clinical outcome. As a novel finding, four polymorphisms in STK4 (rs6017452, rs7271519) and AURKA (rs2273535, rs8173) associated with steroid hormone receptor status both in a Swedish population-based cohort of 783 BC cases and in a Polish familial/early onset cohort of 506 BC cases. In the joint analysis, the minor allele carriers of rs6017452 had more often hormone receptor positive tumours (OR 0.57, 95% CI 0.40-0.81), while homozygotes for the minor allele of rs7271519, rs2273535 and rs8173 had more often hormone receptor negative tumours (2.26, 1.30-3.39; 2.39, 1.14-5.01; 2.39, 1.19-4.80, respectively) than homozygotes for the common allele. BC-specific survival analysis of AURKA suggested that the Swedish carriers of the minor allele of rs16979877, rs2273535 and rs8173 might have a worse survival compared with the major homozygotes. The survival probabilities associated with the AURKA genotypes depended on the tumour phenotype. In the Swedish case-control study, associations with BC susceptibility were observed in a dominant model for three MYBL2 promoter polymorphisms (rs619289, P = 0.02; rs826943, P = 0.03 and rs826944, P = 0.02), two AURKA promoter polymorphisms (rs6064389, P = 0.04 and rs16979877, P = 0.02) and one 3'UTR polymorphism in ZNF217 (rs1056948, P = 0.01). In conclusion, our data confirmed the impact of the previously identified susceptibility locus and provided preliminary evidence for novel susceptibility variants in BC. We provided evidence for the first time that genetic variants at 20q13 may affect hormone receptor status in breast tumours and influence tumour aggressiveness and survival of the patients. Future studies are needed to confirm the prognostic value of our findings in the clinic.

Background: A large number of gene expression profiling (GEP) studies on prognosis of colorectal cancer (CRC) has been performed, but no reliable gene signature for prediction of CRC prognosis has been found. Bioinformatic enrichment tools are a powerful approach to identify biological processes in high-throughput data analysis., Principal Findings: We have for the first time collected the results from the 23 so far published independent GEP studies on CRC prognosis. In these 23 studies, 1475 unique, mapped genes were identified, from which 124 (8.4%) were reported in at least two studies, with 54 of them showing consisting direction in expression change between the single studies. Using these data, we attempted to overcome the lack of reproducibility observed in the genes reported in individual GEP studies by carrying out a pathway-based enrichment analysis. We used up to ten tools for overrepresentation analysis of Gene Ontology (GO) categories or Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in each of the three gene lists (1475, 124 and 54 genes). This strategy, based on testing multiple tools, allowed us to identify the oxidative phosphorylation chain and the extracellular matrix receptor interaction categories, as well as a general category related to cell proliferation and apoptosis, as the only significantly and consistently overrepresented pathways in the three gene lists, which were reported by several enrichment tools., Conclusions: Our pathway-based enrichment analysis of 23 independent gene expression profiling studies on prognosis of CRC identified significantly and consistently overrepresented prognostic categories for CRC. These overrepresented categories have been functionally clearly related with cancer progression, and deserve further investigation.

Background: A large number of gene expression profiling (GEP) studies on colorectal carcinogenesis have been performed but no reliable gene signature has been identified so far due to the lack of reproducibility in the reported genes. There is growing evidence that functionally related genes, rather than individual genes, contribute to the etiology of complex traits. We used, as a novel approach, pathway enrichment tools to define functionally related genes that are consistently up- or down-regulated in colorectal carcinogenesis., Materials and Methods: We started the analysis with 242 unique annotated genes that had been reported by any of three recent meta-analyses covering GEP studies on genes differentially expressed in carcinoma vs normal mucosa. Most of these genes (218, 91.9%) had been reported in at least three GEP studies. These 242 genes were submitted to bioinformatic analysis using a total of nine tools to detect enrichment of Gene Ontology (GO) categories or Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. As a final consistency criterion the pathway categories had to be enriched by several tools to be taken into consideration., Results: Our pathway-based enrichment analysis identified the categories of ribosomal protein constituents, extracellular matrix receptor interaction, carbonic anhydrase isozymes, and a general category related to inflammation and cellular response as significantly and consistently overrepresented entities., Conclusions: We triaged the genes covered by the published GEP literature on colorectal carcinogenesis and subjected them to multiple enrichment tools in order to identify the consistently enriched gene categories. These turned out to have known functional relationships to cancer development and thus deserve further investigation.

Psoriatic arthritis (PsA) is an inflammatory joint disease that is distinct from other chronic arthritides and which is frequently accompanied by psoriasis vulgaris (PsV) and seronegativity for rheumatoid factor. We conducted a genome-wide association study in 609 German individuals with PsA (cases) and 990 controls with replication in 6 European cohorts including a total of 5,488 individuals. We replicated PsA associations at HLA-C and IL12B and identified a new association at TRAF3IP2 (rs13190932, P = 8.56 × 10⁻¹⁷). TRAF3IP2 was also associated with PsV in a German cohort including 2,040 individuals (rs13190932, P = 1.95 × 10⁻³). Sequencing of the exons of TRAF3IP2 identified a coding variant (p.Asp10Asn, rs33980500) as the most significantly associated SNP (P = 1.13 × 10⁻²⁰, odds ratio = 1.95). Functional assays showed reduced binding of this TRAF3IP2 variant to TRAF6, suggesting altered modulation of immunoregulatory signals through altered TRAF interactions as a new and shared pathway for PsA and PsV.

To identify new susceptibility loci for psoriasis, we undertook a genome-wide association study of 594,224 SNPs in 2,622 individuals with psoriasis and 5,667 controls. We identified associations at eight previously unreported genomic loci. Seven loci harbored genes with recognized immune functions (IL28RA, REL, IFIH1, ERAP1, TRAF3IP2, NFKBIA and TYK2). These associations were replicated in 9,079 European samples (six loci with a combined P < 5 × 10⁻⁸ and two loci with a combined P < 5 × 10⁻⁷). We also report compelling evidence for an interaction between the HLA-C and ERAP1 loci (combined P = 6.95 × 10⁻⁶). ERAP1 plays an important role in MHC class I peptide processing. ERAP1 variants only influenced psoriasis susceptibility in individuals carrying the HLA-C risk allele. Our findings implicate pathways that integrate epidermal barrier dysfunction with innate and adaptive immune dysregulation in psoriasis pathogenesis.

Genetic susceptibility accounts for approximately 35% of all colorectal cancer (CRC). Ten common low-risk variants contributing to CRC risk have been identified through genome-wide association studies (GWASs). In our GWAS, 610 664 genotyped single-nucleotide polymorphisms (SNPs) passed the quality control filtering in 371 German familial CRC patients and 1263 controls, and replication studies were conducted in four additional case-control sets (4915 cases and 5607 controls). Known risk loci at 8q24.21 and 11q23 were confirmed, and a previously unreported association, rs12701937, located between the genes GLI3 (GLI family zinc finger 3) and INHBA (inhibin, beta A) [P = 1.1 x 10(-3), odds ratio (OR) 1.14, 95% confidence interval (CI) 1.05-1.23, dominant model in the combined cohort], was identified. The association was stronger in familial cases compared with unselected cases (P = 2.0 x 10(-4), OR 1.36, 95% CI 1.16-1.60, dominant model). Two other unreported SNPs, rs6038071, 40 kb upstream of CSNK2A1 (casein kinase 2, alpha 1 polypeptide) and an intronic marker in MYO3A (myosin IIIA), rs11014993, associated with CRC only in the familial CRC cases (P = 2.5 x 10(-3), recessive model, and P = 2.7 x 10(-4), dominant model). Three software tools successfully pointed to the overrepresentation of genes related to the mitogen-activated protein kinase (MAPK) signalling pathways among the 1340 most strongly associated markers from the GWAS (allelic P value < 10(-3)). The risk of CRC increased significantly with an increasing number of risk alleles in seven genes involved in MAPK signalling events (P(trend) = 2.2 x 10(-16), OR(per allele) = 1.34, 95% CI 1.11-1.61).

Variants in two genes of the IL-23 receptor (R) pathway have recently been shown to be associated with psoriasis vulgaris (PV). We were interested whether the risk conferred by these variants differs between psoriatic skin and joint disease. Four variants of the IL12B and IL23R genes were analyzed in 1,114 PV patients, 748 patients with psoriatic arthritis (PA) and 937 healthy controls before and after stratification for the major psoriasis risk allele at psoriasis susceptibility locus 1 (PSORS1). For both PA and PV, we detected the strongest association with two IL12B single-nucleotide polymorphisms and the corresponding haplotype as reflected by minimal P-values of 10(-7) and highest odds ratios of 1.50 (1.28-1.75) for rs6887695 in PA patients and 1.50 (1.27-1.76) for rs3212227 in the PV cohort, respectively. For IL23R, only rs11209026 showed an association. The results remained significant after correction for multiple testing. No difference was observed after stratification for the PSORS1 risk allele. While confirming recent reports on variants of the IL-23R pathway as susceptibility factors for PV, our study is the first to extend analysis of both genes to PA. However, our results indicate that these variants are not specific risk factors for arthritis, but relevant for susceptibility to psoriasis in general.

Psoriasis is a common inflammatory skin disease with a strong genetic component. We analyzed the genomic copy number polymorphism of the beta-defensin region on human chromosome 8 in 179 Dutch individuals with psoriasis and 272 controls and in 319 German individuals with psoriasis and 305 controls. Comparisons in both cohorts showed a significant association between higher genomic copy number for beta-defensin genes and risk of psoriasis.

Psoriasis vulgaris and atopic dermatitis share a number of features such as chronic cutaneous inflammation and disturbed epidermal barrier function. Genome-wide scans have revealed a conspicuous overlap of susceptibility loci for both diseases involving chromosomal regions 1q21, 3q21, 17q25, and 20p12. Recently, two loss-of-function variants in the gene encoding filaggrin at 1q21 were shown to be strongly associated with atopic dermatitis. In view of a possible genetic overlap of the two skin diseases, we investigated 375 patients suffering from psoriasis vulgaris, 375 patients with psoriatic arthritis, and 376 control probands. Moreover we directly studied expression of filaggrin in 10 patients suffering from psoriasis vulgaris. Our immunohistochemical analysis revealed a checkered pattern with alternating positive broadened or almost absent filaggrin expression. However, no association was found for the two variants of filaggrin (FLG). We conclude that despite a markedly altered filaggrin expression in psoriatic skin, loss-of-function variants of the FLG gene are neither associated with psoriasis vulgaris nor with psoriatic arthritis. The abnormal staining might reflect the altered epidermal differentiation. Our findings imply that the genetic background underlying the epidermal barrier defect in psoriasis is distinct from that found in atopic dermatitis.

The gene for solute carrier family 12 member A8 has recently been proposed as a candidate gene for psoriasis susceptibility (PSORS5) on chromosome 3q based on association of five single nucleotide polymorphisms (SNP) in Swedish patients. To investigate whether this locus is relevant for German psoriasis vulgaris (PsV) patients, we analyzed a group of 210 trios and a case-control group including 375 patients. Based on our investigation of the linkage disequilibrium (LD) structure of SLC12A8, we assayed 35 haplotype tag SNP and grouped them into nine LD-blocks. In the case-control study, we detected an association for six SNP and three LD-based haplotypes. Association was strongest for ss35527511 (chi2 = 11.224, p = 0.0008) and haplotype E-2 (chi2 = 11.788, p = 0.00059) and independent of the presence of an HLA-associated PSORS1 risk allele. Through extended haplotype analysis, we could show that two independent association signals exist in SLC12A8, suggesting allelic heterogeneity. None of the SNP showed association in trios, apart from a weak association of rs2228674 (transmission disequilibrium test statistics p = 0.048), probably due to insufficient power. We conclude that SLC12A8 is a susceptibility locus for PsV. In order to establish the exact nature of this association, efforts to identify the disease-causing variants are ongoing.

Period (Per) genes are involved in regulation of the circadian clock and are thought to modulate several brain functions. We demonstrate that Per2(Brdm1) mutant mice, which have a deletion in the PAS domain of the Per2 protein, show alterations in the glutamatergic system. Lowered expression of the glutamate transporter Eaat1 is observed in these animals, leading to reduced uptake of glutamate by astrocytes. As a consequence, glutamate levels increase in the extracellular space of Per2(Brdm1) mutant mouse brains. This is accompanied by increased alcohol intake in these animals. In humans, variations of the PER2 gene are associated with regulation of alcohol consumption. Acamprosate, a drug used to prevent craving and relapse in alcoholic patients is thought to act by dampening a hyper-glutamatergic state. This drug reduced augmented glutamate levels and normalized increased alcohol consumption in Per2(Brdm1) mutant mice. Collectively, these data establish glutamate as a link between dysfunction of the circadian clock gene Per2 and enhanced alcohol intake.

A DNA variant, rs734232, altering a RUNX1 binding site was recently reported as susceptibility allele at PSORS2 (17q25) in cohorts of psoriasis patients from the US. A testing of this variant in psoriasis patients from Germany did not confirm this association in 300 trios nor in two case-control studies with 281 patients with psoriasis vulgaris and 375 patients with psoriatic arthritis, respectively. These results fail to support rs734232 as a psoriasis susceptibility factor in German psoriasis patients.

Background: Decreased sensitivity to and increased tolerance for the effects of alcohol is a phenotype, which was shown to be associated with an increased risk for alcoholism in humans and was observed in protein tyrosine kinase (PTK) fyn knockout mice., Methods: We performed an association study of genetic variations of PTK fyn in 430 alcohol-dependent patients and 365 unrelated control subjects from two independent samples., Results: In a combined analysis, we found an association of alcohol dependence with the single nucleotide polymorphism (SNP) T137346C in the 5' untranslated region (UTR) of the gene. A relevant association could be excluded for the remaining two informative SNPs. Selection by phenotype showed that a high number of withdrawal symptoms, high amount of alcohol intake, and high maximum number of drinks compared with unrelated control subjects was associated with the SNP in the 5'-UTR region but not with the remaining SNPs., Conclusions: Our results indicate a possible association of alcohol dependence with a genotype of the SNP T137346C of the PTK fyn, with C being the risk allele.