PWE-177 The functional relevance of toll-like receptor 4 mutations in oesophageal adenocarcinoma

摘要: Introduction Altered innate immune signalling may disrupt host-microbe homeostasis and promote an inflammatory microenvironment that favours tumourigenesis. The aim of this project was to assess whether somatic mutations in oesophageal adenocarcinoma (OAC) could interfere with Toll-like receptor (TLR) signalling, a specific focus on TLR4. Method We interrogated the mutational profiles TLR genes 170 OAC samples, which had undergone whole genome sequencing as part ICGC study. performed site-directed mutagenesis created 13 plasmids expressing mutant TLR4 CMV promoter (12 single nucleotide variants (SNVs), one plasmid combined two SNVs). Luciferase reporter gene assays were HEK293 cells stimulated synthetic monophosphoryl lipid A (MPLA) how mutants altered downstream activation nuclear factor kappa B (NF-κB). Two taken forward for transfection into cell line OE33, ELISA used measure cytokine secretion after stimulation MPLA. Results pathway appeared be recurrently mutated missense 23/170 (13.5%) tumour including TLR1 (1.2%), TLR2 (0.6%), (4.7%), TLR5 TLR7 (1.8%), TLR9 MYD88 (1.5%). Based our data another recent study by Dulak et al . 1 , most frequent (5.4% data). One sample contained mutations, E439G F703C. Interestingly, mutation identified both dataset Furthermore, silico modelling suggested disrupts hydrogen bonds binding site LPS MD2. use NF-κB luciferase demonstrated significant decrease ligand-dependent 8/12 tested cells. double F703C revealed further signalling. Similarly, concentration IL-8 lower E439G+F703C transfected OE33 MPLA, comparison wild-type Conclusion is OAC, majority these showed decreased response ligand stimulation, biological relevance relation carcinogenesis being explored. Disclosure interest None Declared. Reference AM, Exome whole-genome esophageal identifies recurrent driver events complexity. Nat Genet. 2013;45(5):478–486.