Polymorphic Variation in NFKB1 and Other Aspirin-Related Genes and Risk of Hodgkin Lymphoma
CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION
Authors: Chang, Ellen T.; Birmann, Brenda M.; Kasperzyk, Julie L.; Conti, David V.; Kraft, Peter; Ambinder, Richard F.; Zheng, Tongzhang; Mueller, Nancy E.
Abstract
We found that regular use of aspirin may reduce the risk of Hodgkin lymphoma (HL), a common cancer of adolescents and young adults in the United States. To explore possible biological mechanisms underlying this association, we investigated whether polymorphic variation in genes involved in nuclear factor-kappa B (NF-kappa B) activation and inhibition, other inflammatory pathways, and aspirin metabolism influences HL risk. Twenty single nucleotide polymorphisms (SNP) in seven genes were genotyped in DNA from 473 classical HL cases and 373 controls enrolled between 1997 and 2000 in a population-based case-control study in the Boston, Massachusetts, metropolitan area and the state of Connecticut. We selected target genes and SNPs primarily using a candidate-SNP approach and estimated haplotypes using the expectation-maximization algorithm. We used multivariable logistic regression to estimate odds ratios (OR) for associations with HL risk. HL risk was significantly associated with rs1585215 in NFKB1 (AG versus AA: OR, 2.1; 95% confidence interval, 1.5-2.9; GG versus AA: OR, 3.5; 95% confidence interval, 2.2-5.7, P(trend) 1.7 X 10(-8)) and with NFKB1 haplotypes (P(global) = 6.0 X 10(-21)). Similar associations were apparent across categories of age, sex, tumor EBV status, tumor histology, and regular aspirin use, although statistical power was limited for stratified analyses. Nominally significant associations with HL risk were detected for SNPs in NFKBIA and CYP2C9. HL risk was not associated with SNPs in IKKA/CHUK, PTGS2/COX2, UDP1A6, or LTC4S. In conclusion, genetic variation in the NF-kappa B pathway seems to influence risk of HL. Pooled studies are needed to detect any heterogeneity in the association with NF-kappa B across HL subgroups, including aspirin users and nonusers. (Cancer Epidemiol Biomarkers Prev 2009;18(3):976-86)
Proteomic Analysis of miR-195 and miR-497 Replacement Reveals Potential Candidates that Increase Sensitivity to Oxaliplatin in MSI/P53wt Colorectal Cancer Cells
CELLS
Authors: Poel, Dennis; Boyd, Lenka N. C.; Beekhof, Robin; Schelfhorst, Tim; Pham, Thang, V; Piersma, Sander R.; Knol, Jaco C.; Jimenez, Connie R.; Verheul, Henk M. W.; Buffart, Tineke E.
Abstract
Most patients with advanced colorectal cancer (CRC) eventually develop resistance to systemic combination therapy. miR-195-5p and miR-497-5p are downregulated in CRC tissues and associated with drug resistance. Sensitization to 5-FU, oxaliplatin, and irinotecan by transfection with miR-195-5p and miR-497-5p mimics was studied using cell viability and clonogenic assays in cell lines HCT116, RKO, DLD-1, and SW480. In addition, proteomic analysis of transfected cells was implemented to identify potential targets. Significantly altered proteins were subjected to STRING (protein-protein interaction networks) database analysis to study the potential mechanisms of drug resistance. Cell viability analysis of transfected cells revealed increased sensitivity to oxaliplatin in microsatellite instable (MSI)/P53 wild-type HCT116 and RKO cells. HCT116 transfected cells formed significantly fewer colonies when treated with oxaliplatin. In sensitized cells, proteomic analysis showed 158 and 202 proteins with significantly altered expression after transfection with miR-195-5p and miR-497-5p mimics respectively, of which CHUK and LUZP1 proved to be coinciding downregulated proteins. Resistance mechanisms of these proteins may be associated with nuclear factor kappa-B signaling and G1 cell-cycle arrest. In conclusion, miR-195-5p and miR-497-5p replacement enhanced sensitivity to oxaliplatin in treatment naive MSI/P53 wild-type CRC cells. Proteomic analysis revealed potential miRNA targets associated with the cell-cycle which possibly bare a relation with chemotherapy sensitivity.