Project description:Background: It is well-established that cancer treatment substantially increases risk of long-term adverse health outcomes among childhood cancer survivors. However, there is limited research on the underlying mechanisms. To elucidate the pathophysiology and a possible causal pathway from treatment exposures to cardiometabolic conditions, we conducted epigenome-wide association studies (EWAS) to identify DNA methylation (DNAm) sites associated with cancer treatment exposures and examined whether treatment-associated DNAm sites mediate associations between specific treatments and cardiometabolic conditions. Methods: We included 2,052 survivors (median age 33.7 years) of European ancestry from the St. Jude Lifetime Cohort Study, a retrospective hospital-based study with prospective clinical follow-up. Cumulative doses of chemotherapy and region-specific radiation were abstracted from medical records. Seven cardiometabolic conditions were clinically assessed. DNAm profile was measured using MethylationEPIC BeadChip with blood-derived DNA. Results: By performing multiple treatment-specific EWAS, we identified 935 5’-cytosine-phosphate-guanine-3′ (CpG) sites mapped to 538 genes/regions associated with one or more cancer treatments at epigenome-wide significance level (P<9×10-8). Among the treatment-associated CpGs, 8 were associated with obesity, 63 with hypercholesterolemia, and 17 with hypertriglyceridemia (False-Discovery-Rate-Adjusted P<0.05). We observed substantial mediation by methylation at four independent CpGs (cg06963130, cg21922478, cg22976567, cg07403981) for association between abdominal field radiotherapy (abdominal-RT) and risk of hypercholesterolemia (70.3%) and by methylation at three CpGs (cg19634849, cg13552692, cg09853238) for association between abdominal-RT and hypertriglyceridemia (54.6%). In addition, three CpGs (cg26572901, cg12715065, cg21163477) partially mediated the association between brain-RT and obesity with 32.9% mediation effect and two CpGs mediated the association between corticosteroids and obesity (cg22351187, 14.2%) and between brain-RT and hypertriglyceridemia (cg13360224, 10.5%). Notably, several mediator CpGs reside in the proximity of well-established dyslipidemia genes: cg21922478 (ITGA1) and cg22976567 (LMNA). Conclusions: In childhood cancer survivors, cancer treatment exposures are associated with DNAm patterns present decades following the exposure. Treatment-associated DNAm sites may mediate the causal pathway from specific treatment exposures to certain cardiometabolic conditions, suggesting the utility of DNAm sites as risk predictors and potential mechanistic targets for future intervention studies.

Project description:Background: Increased epigenetic age acceleration (EAA) in survivors of childhood cancer is associated with specific treatment exposures, unfavorable health behaviors, and presence of certain chronic health conditions. To better understand inter-individual variability, we investigated the genetic basis underlying EAA. Methods: Genome-wide association studies of EAA based on multiple epigenetic clocks (Hannum, Horvath, PhenoAge, and GrimAge) were performed. MethylationEPIC BeadChip array and whole-genome sequencing data were generated with blood-derived DNA from participants in the St. Jude Lifetime Cohort Study (discovery: 2,138 pre-existing and 502 newly generated data, all survivors; exploratory: 282 community controls). Linear regression models were fit for each epigenetic age against allelic dose of each genetic variant, adjusting for age at sampling, sex, and cancer treatment exposures. Fixed-effects meta-analysis was used to combine summary statistics from two discovery data sets. LD (Linkage disequilibrium) score regression was used to estimate single-nucleotide polymorphism (SNP)-based heritability. Results: For EAA-Horvath, a genome-wide significant association was mapped to SELP gene with the strongest SNP rs732314 (meta-GWAS: β=0.57, P=3.30×10-11). Moreover, the stratified analysis of the association between rs732314 and EAA-Horvath showed substantial heterogeneity between children and adults (meta-GWAS: β=0.97 vs. 0.51, I2=73.1%) as well as between survivors with and without chest/abdominal/pelvic-RT exposure (β=0.64 vs. 0.31, I2=66.3%). For EAA-Hannum, an association was mapped to HLA locus with the strongest SNP rs28366133 (meta-GWAS: β=0.78, P=3.78×10-11). There was no genome-wide significant hit for EAA-PhenoAge or EAA-GrimAge. Interestingly, among community controls, rs732314 was associated with EAA-Horvath (β=1.09, P=5.43×10-5), whereas rs28366133 was not associated with EAA-Hannum (β=0.21, P=0.49). The estimated heritability was 0.33 (SE=0.20) for EAA-Horvath and 0.17 (SE=0.23) for EAA-Hannum, but close to zero for EAA-PhenoAge and EAA-GrimAge. Conclusions: We identified novel genetic variants in SELP gene and HLA region associated with EAA-Horvath and EAA-Hannum, respectively, among survivors of childhood cancer. The new genetic variants in combination with other replicated known variants can facilitate identification of survivors at higher risk in developing accelerated aging, and potentially inform drug targets for future intervention strategies among vulnerable survivors.

Project description:Background: Mechanisms by which prior tuberculosis (TB) increases long-term risk for cancer, cardiovascular, and neurological disorders remain unclear, particularly in people with HIV (PWH). This study investigated DNA methylation (DNAm) patterns and associated pathways in PWH with and without prior TB infection. Methods: DNAm was analyzed in blood samples from 30 PWH (10 with prior latent TB infection [LTBI], 10 with previous successfully treated active TB, and 10 with no TB) using the Illumina MethylationEPIC BeadChip covering over 850,000 CpG sites. Epigenetic age was estimated, and age acceleration was calculated. Differentially methylated CpGs (dmCpGs) and regions (DMRs) were identified, and functional enrichment analyses for Gene Ontology, KEGG pathways, PANTHER database, and gene set enrichment analysis (DisGeNET, dbGaP) were performed. Statistical significance was set at a false discovery rate (FDR) of <0.05. Results: PWH exhibited significant epigenetic age acceleration, with a mean of 19.32 ± 10.82 years greater than chronological age. This accelerated aging was more pronounced in individuals with any prior TB infection (21.60 ± 12.03 years) compared to those without TB (17.42 ± 9.38 years). In the prior active TB vs. no TB comparison, 7,461 dmCpGs were identified, corresponding to 150 DMRs (p<0.05), with top associated genes including GRAMD1C (hypomethylation), DPP6 (hypermethylation), and HDAC4 (hypomethylation). In the LTBI vs. no TB comparison, 8,598 dmCpGs were observed, corresponding to 39 DMRs (p<0.05), associated with genes such as PLEKHG5 (hypermethylation), STK32C (hypermethylation), and SPATC1L. When comparing any prior TB (active or latent) to no TB, 71,774 dmCpGs and 14 DMRs were identified, including genes like PLEKHG5, KCNN3, and BRSK2. Pathway analyses of prior TB (active or latent) vs. no TB revealed enrichment in neurogenesis, neuron differentiation, axon guidance, and neuroactive ligand signaling. Additional enriched pathways included those related to platelet activation, vascular muscle contraction, and chemokine signaling. Cancer-related pathways such as proteoglycans in cancer, small cell lung cancer, prostate cancer, breast cancer, hepatocellular carcinoma, and thyroid cancer were also enriched. PANTHER analysis showed consistent enrichment in the Wnt signaling pathway and inflammation-mediated pathways across compared groups. DisGeNET analysis linked prior TB DNAm patterns to lymphoid leukemia, while dbGaP analysis identified associations with phenotypes like asthma, body mass index, tunica media, and lymphocyte count Conclusion: Prior TB infection in PWH is associated with distinct DNAm changes in pathways related to neural function, cardiovascular health, and cancer risk, and is linked to more pronounced epigenetic age acceleration, suggesting epigenetic mechanisms for TB-related long-term complications.

Dataset Information

Epigenome-wide DNA Methylation Profiling in the Investigation of Treatment and Life-Course Exposures and Adverse Health Outcomes in Survivors of Childhood Cancer from the St. Jude Lifetime Cohort

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets