Abstract 3977: Molecular reprogramming in high-risk progressive neuroblastoma

Abstract High risk disease in infants with neuroblastoma significantly contributes to the pediatric cancer death. We investigated the molecular reprogramming in neuroblastoma cells that drives favorable neuroblastoma to aggressive disease. For this, multi-site aggressive tumors from animals that received parental (SH-SY5Y) cell xenotransplantation were assayed and compared to the animals with subtle non-metastatic xenografts. Establishment of highly malignant neuroblastoma cell line (NBP4) and its comparative (with SH-SY5Y) cytogenetic/phenotypic physiognomies were reported elsewhere. Ex vivo whole genome gene expression identified a total of 33 genes upregulated and another 33 genes downregulated (>40 fold change) in NBP4 cells as opposed to parental SH-SY5Y cells. QPCR analysis revealed a conforming upregulation of SEMA3D, MEGF10, GRB10 and suppression of RD3 in multi-site aggressive tumors. Tissue microarray (72 core) constructed with aggressive multiple tumors and non-progressive controls coupled with immunohistochemistry showed robust levels of SEMA3D, GRB10, MEGF10 and complete loss of KCNQ2, KRTAP1-1 and RD3. Consistently, translational modifications of SEMA3D, GRB10, MEGF10, KCNQ2 and RD3 in multi-site aggressive tumors were validated with immunoblotting. More importantly, selective knockdown of KCNQ2 or KRTAP1-1 in parental SH-SY5Y cells robustly modified the cellular phenotype and significantly increased the tumorosphere formation. Conversely, discrete muting of GRB10, KIAA2022, MEGF10 or SEMA3D ex vivo (in aggressive NBP4 cells) endorsed the cellular differentiation, adherence and resulted in complete regulation of tumorosphere formation. Together, these data suggests that the milieu based molecular reprograming of the neuroblastoma cells drives the development of high-risk disease and further implies that GRB10, KIAA2022, MEGF10, SEMA3D, RD3 and KCNQ2 may concert and orchestrate the disease progression. Signal flow-through and molecular driver(s) that orchestrate favorable to high-risk disease are yet to be understood and are currently in progress in our laboratory. Citation Format: Vijayabaskar Pandian, Faizan H. Khan, Satish K. Ramraj, Sheeja Aravindan, Mohan Natarajan, Terence S. Herman, Natarajan Aravindan. Molecular reprogramming in high-risk progressive neuroblastoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3977. doi:10.1158/1538-7445.AM2014-3977