Abstract 1209: The association between the cell cycle control pathway and pediatric germ cell tumors

Abstract

Abstract Pediatric germ cell tumors (GCTs) account for approximately 6% of childhood cancers. GCTs are heterogeneous but are grouped together due to a common cell of origin, the primordial germ cell. GCTs are predicted to have high heritability, therefore, genetic association studies are paramount in understanding GCT etiology. Genome-wide association (GWA) studies commonly ignore the aggregate effect of SNPs/genes with weaker individual associations. Pathway-based approaches provide the opportunity to interrogate joint SNP effects in pathways of interest. The cell cycle control pathway is a plausible candidate pathway given the knowledge that alterations in the the mitotic-meiotic switch may lead to genetic instability and initiate GCT development. In this analysis we evaluated a set of 94 genes associated with cell cycle control using data from a case-parent triad study of pediatric GCT. Genes involved in cell cycle control were identified using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. We also included additional genes based on reports in the literature suggesting a role in cell cycle control in GCTs, including STRA832, 33, CYP26B134, CKS1B35, and E2F636. Variants within 25,000 base pairs upstream or downstream of the gene were selected for inclusion resulting in a total of 2,846 SNPs included in the analysis. Genotyping data were generated using the Illumina HumanCore Exome Array for 867 GCT cases and their unaffected parents. Preliminary results evaluating individual effects of SNPs in the pathway were conducted using the transmission disequilibrium test (TDT). We did not observe any individual SNP associations that reached genome-wide significance; however, suggestive associations were observed for SNPs located in CDKN2C (p=0.000208), MCM7 (p=0.000787), RB1 (p=0.000798), RBL2 (p=0.00250) and TP53 (p=0.00257). Replication of these findings will be conducted using data from a record linkage case-control study from neonatal biobanks in California and Michigan (N=837 cases and 1057 controls). In addition, we will utilize pathway-based approaches to jointly evaluate the effects of genes in this pathway, including Gene Set Enrichment Analysis for Genome wide association study (i-GSEA4GWAS), MetXcan for functional significance, and Family-based rare-variant association analysis (PedGene). In conclusion, our results suggest that genes within the cell-cycle control pathway play a role in the etiology of pediatric GCT. Citation Format: Aubrey K. Hubbard, Nathan Pankratz, Spencer T. Kelley, John J. Meredith, Jenny N. Poynter. The association between the cell cycle control pathway and pediatric germ cell tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1209.