BACKGROUND: Secreted protein acidic and rich in cysteine (SPARC), a 
matricellular glycoprotein, modulates cellular interaction with the 
extracellular matrix and is capable of altering the growth of various cancers. 
We therefore sought to determine the effect of SPARC expression on 
medulloblastoma tumour growth and angiogenesis.
METHODS: To this extent, we selected three SPARC full-length cDNA overexpressed 
clones (Daoy-SP). Consequences of SPARC overexpression were studied in terms of 
cell growth, angiogenesis using co-culture assay in vitro, dorsal skin-fold 
chamber assay in vivo, PCR Array for human angiogenic genes, as well as western 
blotting for angiogenic molecules and tumour growth, in an orthotopic tumour 
model.
RESULTS: The SPARC protein and mRNA levels were increased by approximately 
three-fold in Daoy-SP cells compared with parental (Daoy-P) and vector (Daoy-EV) 
controls. Daoy-SP clones reduced tumour cell-induced angiogenesis in vitro and 
in vivo, and formed small tumours with fewer blood vessels when compared with 
controls. Matrix metalloprotease-9 (MMP-9) and vascular endothelial growth 
factor (VEGF) expression were decreased in Daoy-SP clones. Further, inhibition 
of MMP-9 expression caused SPARC-mediated inhibition of angiogenesis and tumour 
growth as MMP-9 rescued SPARC-mediated anti-angiogenic effect in vitro and 
tumour growth inhibition in vivo.
CONCLUSION: Overexpression of SPARC decreases angiogenesis, which leads to 
decreased tumour growth. Further, the role of MMP-9 could be attributed to the 
anti-angiogenic effect of SPARC.