Finally, elevated expression of IGF-1R and IGF2 in gliomas associated with poor patient survival and tumor expression levels of IGFBP6 directly correlated with overall survival time in patients with GBM.
IGFBP-6 showed significantly decreased expression in 170 out of 263 patients based on IHC data and this was associated with a larger tumor size (P<0.001) and poorly-differentiated adenocarcinoma (P=0.001), as well as with palliative gastrectomy (P=0.015).
Here, we report that hypoxia induced the expression of insulin-like growth factor binding protein-6 (IGFBP-6), a tumor repressor, in human and rodent vascular endothelial cells (VECs) via a hypoxia-inducible factor (HIF)-mediated mechanism.
Therefore, increased induction of IGFBP6 gene or protein expression in oral tumors could be regarded as a potential predictive marker of tumor sensitivity and could be used for prognostic purposes, since a significant correlation could be observed between increased induction of apoptotic cell death and elevated levels of IGFBP6 in these tumors.
In small IGFBP-6-expressing xenografts where tumour development had apparently been arrested, haematoxylin--eosin and TUNEL staining revealed numerous apoptotic cells.