Poster Presentation Advances in Neuroblastoma Research Congress 2016

Characterization of patient-derived xenograft neuroblastoma cells (#234)

Camilla Persson 1 , My Merselius 1 , Daniel Bexell 1 , David Gisselsson 2 3 , Noémie Braekeveldt 1 , Siv Beckman 1 , Sofie Mohlin 1 , Sven Påhlman 1 , Caroline Wigerup 1
  1. Translational Cancer Research, Lund University, Lund, Sweden
  2. Department of Clinical Genetics, Lund University, Lund, Sweden
  3. Department of Pathology, University and Regional Laboratories, Lund, Sweden

We recently established a neuroblastoma patient-derived xenograft (PDX) model from which we have isolated cells and established PDX sublines. The PDX cells express common neuroblastoma markers and retain patient-specific genomic aberrations over several passages. We believe that PDX cells are relevant models for identifying new treatment targets in neuroblastoma since they retain in vivo tumorigenic and metastatic capacity, including to bone marrow.

The PDX cells are grown in serum-free, stem-cell promoting medium as spheres in order to maintain an immature phenotype. Serum induces spontaneous differentiation of neural stem cells, which results in loss of stem-like properties. By culturing PDX cells in the presence of serum, we observed a trend towards a more differentiated phenotype as cells started to adhere, proliferate slower and increased their expression of known differentiation markers. Thus, culturing PDX cells in serum-free conditions is important for maintaining a more undifferentiated phenotype.

Furthermore, the PDX cells express Hypoxia Inducible Factor 2α (HIF-2α) at normoxia. We have previously shown that presence of HIF-2α positive neuroblastoma cells in a perivascular niche associates with poor prognosis. Moreover, these cells seem to have a less differentiated phenotype. It has also been shown that HIF-2α is expressed in sympathetic neuroblasts during early sympathetic nervous system development/embryogenesis (w6.5) in humans. This might suggest that the PDX cells are arrested in an early developmental stage.

Finally, for future drug screening, we grew PDX cells as a monolayer culture on laminin since sphere culturing is more cumbersome. PDX cells grown on laminin showed a differentiated morphology and increased expression of various differentiation markers. An increased survival was also observed in laminin-cultured cells. Although laminin seems to promote differentiation, PDX cells grown on laminin retained tumorigenic and metastatic capacity in vivo and formed spheres in vitro after short-term laminin culture.