Phenotypic and Genotypic Changes in Metastatic Neuroblastoma

Objective: Children with neuroblastoma (NB) rarely die from primary disease but rather from recurrent, metastatic disease. It is critical to further characterize the biologic differences between the primary tumor and the... [ view full abstract ]

Objective: Children with neuroblastoma (NB) rarely die from primary disease but rather from recurrent, metastatic disease. It is critical to further characterize the biologic differences between the primary tumor and the metastatic cells. We hypothesize that cells derived from liver and bone marrow metastases in a murine model will be phenotypically and genotypically different when compared to the parental cell of origin.

Methods: Using the cell lines CHLA-255 and SH-SY5Y, multiple metastatic cell lines were created de novo from the bone marrow and liver of NSG mice utilizing a previously described metastatic mouse model of minimal residual disease. Response to increasing doses of chemotherapy (etoposide) was analyzed using DIMSCAN cell viability assay. Gene expression was characterized using a low-density metastatic pathway PCR microarray. The PCR-array was performed using the parental and metastatic cell lines from the neuroblastoma cell lines.

Results: Metastatic cell lines showed significantly decreased response to increasing doses of etoposide compared to the parental cell line (p<0.05). PCR array revealed numerous genes, which were upregulated in the metastatic cells compared to the parental. Numerous neuroblastoma associated genes appeared to be upregulated including APC, CCL2/7, FGFR4, MET and NR4A3. These genes play critical roles in cell adhesion, migration, proliferation and survival.

Conclusion: Metastatic neuroblastoma cells appear to have significantly different gene expression and response to standard chemotherapy. These data provide the background for further studies to elucidate the effects of novel treatments particularly on genes specific to metastatic disease in our novel murine model of minimal residual disease.