CELF4 Variant and Anthracycline-Related Cardiomyopathy: A Children's Oncology Group Genome-Wide Association Study

Abstract

Purpose: Interindividual variability in the dose-dependent association between anthracyclines and cardiomyopathy suggests that genetic susceptibility could play a role. The current study uses an agnostic approach to identify genetic variants that could modify cardiomyopathy risk.

Methods: A genome-wide association study was conducted in childhood cancer survivors with and without cardiomyopathy (cases and controls, respectively). Single-nucleotide polymorphisms (SNPs) that surpassed a prespecified threshold for statistical significance were independently replicated. The possible mechanistic significance of validated SNP(s) was sought by using healthy heart samples.

Results: No SNP was marginally associated with cardiomyopathy. However, SNP rs1786814 on the CELF4 gene passed the significance cutoff for gene-environment interaction (Pge = 1.14 × 10(-5)). Multivariable analyses adjusted for age at cancer diagnosis, sex, anthracycline dose, and chest radiation revealed that, among patients with the A allele, cardiomyopathy was infrequent and not dose related. However, among those exposed to greater than 300 mg/m(2) of anthracyclines, the rs1786814 GG genotype conferred a 10.2-fold (95% CI, 3.8- to 27.3-fold; P < .001) increased risk of cardiomyopathy compared with those who had GA/AA genotypes and anthracycline exposure of 300 mg/m(2) or less. This gene-environment interaction was successfully replicated in an independent set of anthracycline-related cardiomyopathy. CUG-BP and ETR-3-like factor proteins control developmentally regulated splicing of TNNT2, the gene that encodes for cardiac troponin T (cTnT), a biomarker of myocardial injury. Coexistence of more than one cTnT variant results in a temporally split myofilament response to calcium, which causes decreased contractility. Analysis of TNNT2 splicing variants in healthy human hearts suggested an association between the rs1786814 GG genotype and coexistence of more than one TNNT2 splicing variant (90.5% GG v 41.7% GA/AA; P = .005).

Conclusion: We report a modifying effect of a polymorphism of CELF4 (rs1786814) on the dose-dependent association between anthracyclines and cardiomyopathy, which possibly occurs through a pathway that involves the expression of abnormally spliced TNNT2 variants.

Trial registration: ClinicalTrials.gov NCT00082745.

Conflict of interest statement

Authors' disclosures of potential conflicts of interest are found in the article online at www.jco.org. Author contributions are found at the end of this article.

© 2016 by American Society of Clinical Oncology.

Figures

Fig 1.

P values of gene-by-environment interactions for the gene CELF4 region. Gene CELF4 and adjacent genes in the region are shown in the lower panel, and the unbroken blue line indicates the recombination rate within the region. Each filled circle represents the P value of a gene-by-environment interaction for one single-nucleotide polymorphism (SNP) in the non-Hispanic whites discovery set. SNPs in the region were colored according to their degrees of correlation (r2) with rs1786814, which was estimated internally by LocusZoom38 on the basis of Utah residents of Northern and Western European ancestry (EUR) haplotypes of 1,000 genomes.

Fig 2.

Risk of cardiomyopathy by anthracycline dose and genotype status (AA, GA, GG). Odds ratios (ORs) were calculated based on model 2, which treated anthracycline dose as a continuous variable (reference group: AA genotype with no anthracycline exposure).

Fig 3.

Proposed pathogenesis of anthracycline-related cardiomyopathy. cTnT, cardiac troponin T; Dox-, doxorubicin; HA, hyaluronic acid; IRP1, iron regulatory protein 1; NAD(P)H, nicotinamide adenine dinucleotide phosphate hydrogen; ROS, reactive oxygen species.