👤 Kostas K Tsilidis

Numerous genetic variants have been identified by genome-wide association studies as being associated with colorectal cancer (CRC) risk. Metabolome-wide association analysis was performed for 187 CRC-associated genetic variants using genomic data and untargeted Show less

The role of lipid-perturbing medications in cancer risk is unclear. We employed cis-Mendelian randomization and colocalization to evaluate the role of 5 lipid-perturbing drug targets (ANGPTL3, ANGPTL4, APOC3, CETP, and PCSK9) in risk of 5 cancers (breast, colorectal, head and neck, ovarian, and prostate). We triangulated findings using pre-diagnostic protein measures in prospective analyses in EPIC (977 colorectal cancer cases, 4080 sub-cohort members) and the UK Biobank (860 colorectal cancer cases, 50 177 controls). To gain mechanistic insight into the role of ANGPTL4 in carcinogenesis, we examined the impact of the ANGPTL4 p. E40K loss-of-function variant on differential gene expression in normal colon tissue in BarcUVa-Seq. Finally, we evaluated the association of colon tumor ANGPTL4 expression with cancer-specific mortality in TCGA. In analysis of 78 473 cases and 107 143 controls, genetically proxied circulating ANGPTL4 inhibition was associated with reduced colorectal cancer risk (ORSD decrease = 0.76, 95% confidence interval [CI] = 0.66 to 0.89, P = 5.52 × 10-4, PPcolocalization = 0.83). This association was replicated using pre-diagnostic circulating ANGPTL4 concentrations in EPIC (hazard ratio [HR]log10 decrease = 0.91, 95% CI = 0.84 to 0.98, P = .01) and the UK Biobank (HRSD decrease = 0.93, 95% CI = 0.86 to 0.99, P = .03). In gene-set enrichment analysis of differential gene expression in 445 colon tissue samples, ANGPTL4 loss-of-function down-regulated several cancer-related biological pathways (PFDR < .05), including those involved in cellular proliferation, epithelial-to-mesenchymal transition, and bile acid metabolism. In analysis of 465 colon cancer patients, lower ANGPTL4 tumor expression was associated with reduced colorectal cancer-specific mortality risk (HRlog2 decrease = 0.66, 95% CI = 0.50 to 0.87, P = 2.92 × 10-3). Our integrative proteogenomic and observational analyses suggest a potential protective role of lower circulating ANGPTL4 concentrations in colorectal cancer risk. These findings support further evaluation of ANGPTL4 as a therapeutic target for colorectal cancer prevention. Show less

Fatty acid synthase (FAS) is the major enzyme of lipogenesis. It catalyzes the NADPH-dependent condensation of acetyl-CoA and malonyl-CoA to produce palmitic acid. Transcription of the FAS gene is controlled synergistically by the transcription factors ChREBP (carbohydrate response element-binding protein), which is induced by glucose, and SREBP-1 (sterol response element-binding protein-1), which is stimulated by insulin through the PI3K/Akt signal transduction pathway. We investigated whether the genetic variability of the genes encoding for ChREBP, SREBP and FAS (respectively, MLXIPL, SREBF1 and FASN) is related to breast cancer risk and body-mass index (BMI) by studying 1,294 breast cancer cases and 2,452 controls from the European Prospective Investigation on Cancer (EPIC). We resequenced the FAS gene and combined information of SNPs found by resequencing and SNPs from public databases. Using a tagging approach and selecting 20 SNPs, we covered all the common genetic variation of these genes. In this study we were not able to find any statistically significant association between the SNPs in the FAS, ChREBP and SREPB-1 genes and an increased risk of breast cancer overall and by subgroups of age, menopausal status, hormone replacement therapy (HRT) use or BMI. On the other hand, we found that two SNPs in FASN were associated with BMI. Show less