| 1. |
- Klimosch, Sascha N., et al.
(författare)
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Functional TLR5 Genetic Variants Affect Human Colorectal Cancer Survival
- 2013
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Ingår i: Cancer Research. - 1538-7445. ; 73:24, s. 7232-7242
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Tidskriftsartikel (refereegranskat)abstract
- 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-1 beta 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. (C)2013 AACR.
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| 2. |
- Lascorz, Jess, et al.
(författare)
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Association study identifying polymorphisms in CD47 and other extracellular matrix pathway genes as putative prognostic markers for colorectal cancer
- 2013
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Ingår i: International Journal of Colorectal Disease. - : Springer Science and Business Media LLC. - 1432-1262 .- 0179-1958. ; 28:2, s. 173-181
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Tidskriftsartikel (refereegranskat)abstract
- 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. 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. 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). 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.
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| 3. |
- Siegert, Sabine, et al.
(författare)
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Genome-wide investigation of gene-environment interactions in colorectal cancer
- 2013
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Ingår i: Human Genetics. - : Springer Science and Business Media LLC. - 1432-1203 .- 0340-6717. ; 132:2, s. 219-231
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC), one of the most frequent neoplasias worldwide, has both genetic and environmental causes. As yet, however, gene-environment (G x 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 x 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 x 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 x E analysis.
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