| 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. |
- Wang, Hui, et al.
(författare)
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A coding IRAK2 variant compromises TLR signaling and is associated with colorectal cancer survival.
- 2014
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 289:33, s. 23123-23131
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Tidskriftsartikel (refereegranskat)abstract
- Within innate immune signaling pathways, Interleukin-1 receptor (IL-1R&)-associated kinases (IRAKs) fulfill key roles downstream of multiple Toll-like receptors (TLR) and the IL-1R. Whereas 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 TLR-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 uncovered a significant genetic association of rs35060588 with colorectal cancer survival. This for the first time firmly implicates human IRAK2 in human disease and highlights the R214G IRAK2 variant as a potential novel and broadly applicable biomarker for disease or as a therapeutic intervention point.
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