Abstract 4374: The role of glycine decarboxylase in neuroblastoma

Abstract Neuroblastoma is the most common cancer in infants. While the low and intermediate risk groups of neuroblastoma patients have ≥90% five-year-survival rates, the high-risk group has only 40-50% five-year-survival rates despite multimodal therapies. Genomic amplification of the oncogene MYCN (a member of the MYC family of transcription factors) is a major cause of high-risk neuroblastoma and is strongly correlated with poor prognosis. A key function of MYCN is to promote cell growth and proliferation, which requires increased cellular metabolism to meet the biosynthetic demand for growth. Serine-Glycine-One-Carbon (SGOC) metabolism is particularly important in sustaining cell proliferation by producing amino acids for protein synthesis and one-carbon units for nucleotide production. We investigated the role of glycine decarboxylase (GLDC) in neuroblastoma. GLDC catalyzes the first reaction in glycine cleavage, which generates one-carbon unit and reduced NADH. Analysis of gene expression data from two cohorts of neuroblastoma patients showed that GLDC expression is correlated with advanced stages, high-risk disease and poor prognosis in neuroblastoma. We found that GLDC is required for neuroblastoma cell proliferation as silencing GLDC expression by shRNA induced G1 cell cycle arrest. Consistent with this observation, microarray gene expression profiling revealed that GLDC knockdown resulted in a significant decrease in the expression of E2F target genes. In addition, we obtained evidence that GLDC is a direct target gene of MYCN. Knockdown of MYCN expression reduced GLDC mRNA and protein expression, and overexpression of MYCN increased GLDC mRNA and protein levels. Moreover, chromatin immunoprecipitation with quantitative PCR demonstrated that MYCN binds to the GLDC promoter region. These findings suggest an important role of GLDC in driving neuroblastoma cell proliferation, which could be exploited as a therapeutic strategy against high-risk neuroblastoma with MYCN amplification. Citation Format: Ahmet Alptekin, Jane Ding, Bingwei Ye, Han-Fei Ding. The role of glycine decarboxylase in neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4374.