Heparanase (<i>HPSE</i>) expression was identified in 50% of GBM tumours by immunostaining, and was characterised by a high intratumoural heterogeneity of the presence of the HPSE protein.
Together, we report that TGLI1 is a novel mediator of glioblastoma angiogenesis and that heparanase is a novel transcriptional target of TGLI1, shedding new light on the molecular pathways that support tumor angiogenesis and aggressive growth.
We found that heparanase promoters are differentially methylated among three glioblastoma cell lines; however, all these cells expressed baseline levels of heparanase.
The authors found that heparanase mRNA is greatly increased in gliomas including oligodendroglioma (9 samples), anaplastic astrocytoma (11 samples), and GBM (13 samples) as compared with healthy brain mRNA (3 samples).
These results indicate that the expression of heparanase was downregulated in GBM in vivo, which rarely metastasizes to distant organs outside the central nervous system.