Overall, 12.5%, 17.7%, and 71.9% of the tumors stained positive for DCN, SPARC and stabilin-1 respectively and correlated to age, stage and N-MYC status in 96 children and adolescents with neuroblastoma.
We observed that overexpression of SPARC in SK-N-BE(2) and NB1691 cells reduced radiation induced angiogenesis in an in vivo mouse dorsal skin model and an ex vivo chicken CAM (chorioallantoic-membrane) model and also reduced tumor size in subcutaneous mouse tumor models of NB.
Here, we developed a novel in vivo model of stroma-rich neuroblastoma using non-tumorigenic SHEP cells with modulated levels of SPARC, mixed with tumorigenic KCNR cells.
Taken together, these results illustrate the critical role of ER stress in regulating autophagy-mediated apoptosis in SPARC-overexpressed neuroblastoma cells and radiation treatment.
Its divergent actions reflect the complexity of this protein, because in certain types of cancers, such as melanomas and gliomas, SPARC is associated with a highly aggressive tumor phenotype, while in others, mainly ovarian, neuroblastomas and colorectal cancers, SPARC may function as a tumor suppressor.