Quantitative expression of serum biomarkers involved in angiogenesis and inflammation, in patients with glioblastoma multiforme: Correlations with clinical data

Glioblastoma multiforme (GBM) represents a very aggressive brain tumor. Angiogenesis is the formation of a network of new blood vessels, from preexisting ones. It plays an important role in the formation of the tumor, as it supplies it with oxygen and nutrients. Angiogenesis and inflammation play essential roles in glioblastoma development. These processes are regulated by the balance of a few molecules, acting as pro- or antiangiogenic and pro- or anti-inflammatory factors. The purpose of our study was to evaluate the expression of 7 markers involved in angiogenesis and inflammation pathways in patients with glioblastoma. VEGF, PDGF-bb, IGF-1, TGF-beta, TNF-alpha, IL-6 and IL-8 levels were measured using the ELISA method, in the preoperative sera of 14 patients with histopathologically confirmed glioblastoma multiforme and 32 healthy patients. Serum levels of PDGF-bb, IGF-1 and IL-8 were significantly higher in patients with GBM, compared to the control group (p-value < 0.01). A statistically significant correlation has been found between IGF-1 and IL-6 levels (rho - -0.53, p-value < 0.05) and also between TNF-alpha and IL-6 levels (rho = 0.60, p-value < 0.05). Statistically significant associations have been found between the presence of low levels of IL-8 and the development of coagulation necrosis (p-value < 0.05), high levels of VEGF and development of ischemic necrosis (p-value < 0.01) and high levels of IL-8 and the development of endothelial hyperplasia (p-value < 0.05). We have observed no statistically significant associations between the serum levels of the markers and the survival rates.