Polymorphisms in genes related to one-carbon metabolism are not related to pancreatic cancer in PanScan and PanC4

PURPOSE

The evidence of a relation between folate intake and one-carbon metabolism (OCM) with pancreatic cancer (PanCa) is inconsistent. In this study, the association between genes and single-nucleotide polymorphisms (SNPs) related to OCM and PanCa was assessed.

METHODS

Using biochemical knowledge of the OCM pathway, we identified thirty-seven genes and 834 SNPs to examine in association with PanCa. Our study included 1,408 cases and 1,463 controls nested within twelve cohorts (PanScan). The ten SNPs and five genes with lowest p values (<0.02) were followed up in 2,323 cases and 2,340 controls from eight case-control studies (PanC4) that participated in PanScan2. The correlation of SNPs with metabolite levels was assessed for 649 controls from the European Prospective Investigation into Cancer and Nutrition.

RESULTS

When both stages were combined, we observed suggestive associations with PanCa for rs10887710 (MAT1A) (OR 1.13, 95 %CI 1.04-1.23), rs1552462 (SYT9) (OR 1.27, 95 %CI 1.02-1.59), and rs7074891 (CUBN) (OR 1.91, 95 %CI 1.12-3.26). After correcting for multiple comparisons, no significant associations were observed in either the first or second stage. The three suggested SNPs showed no correlations with one-carbon biomarkers.

CONCLUSIONS

This is the largest genetic study to date to examine the relation between germline variations in OCM-related genes polymorphisms and the risk of PanCa. Suggestive evidence for an association between polymorphisms and PanCa was observed among the cohort-nested studies, but this did not replicate in the case-control studies. Our results do not strongly support the hypothesis that genes related to OCM play a role in pancreatic carcinogenesis.

Association of IL10 and other immune response- and obesity-related genes with prostate cancer in CLUE II

BACKGROUND

Chronic intra-prostatic inflammation and obesity are thought to influence prostate carcinogenesis. Thus, variants in genes in these pathways could be associated with prostate cancer risk.

METHODS

We genotyped 17 common single nucleotide polymorphisms (SNPs) in RNASEL, TLR4, IL1B, IL6, IL8, IL10, TNF, CRP, ADIPOQ, LEP, PPARG, and TCF7L2 in 258 white prostate cancer cases and 258 matched controls nested in CLUE II. Single-locus analyses were conducted using conditional logistic regression. TagSNPs were selected in IL10, CRP, and TLR4 and haplotype analyses were done.

RESULTS

The A allele of IL10 -1082G>A (rs1800896), known to result in lower levels of this anti-inflammatory cytokine, was positively associated with risk (AG vs. GG, OR = 1.69, 95% CI: 1.10-2.60; AA vs. GG, OR = 1.81, 95% CI: 1.11-2.96; P (trend) = 0.02). Associations of IL10 haplotypes with prostate cancer were explained by high linkage disequilibrium between two tagSNPs (rs1800890 and rs3024496) and -1082G>A. A TLR4 candidate SNP (rs4986790; AG/GG vs. AA, OR = 0.60, 95% CI: 0.33-1.08; P(trend) = 0.09), known to have decreased expression and be associated with lower circulating levels of inflammatory mediators, and tagSNP (rs10116253; CC vs. TT, OR = 3.05, 95% CI: 1.11-8.41), but not haplotypes, were associated with risk. None of the other candidate SNPs or haplotypes was statistically significantly associated with risk.

CONCLUSION

Our prospective study suggests that genetic variation in IL10 and possibly TLR4 is associated with prostate cancer risk. Although none of the SNPs in the obesity genes tested was associated, this does not rule out a complex role of obesity and its metabolic consequences in prostate cancer etiology.