Quantitative mRNA expression of genes involved in angiogenesis, coagulation and inflammation in multiforme glioblastoma tumoral tissue versus peritumoral brain tissue: lack of correlation with clinical data

Glioblastoma multiforme is a very aggressive brain tumor. Angiogenesis, the formation of new blood vessels from pre-existing ones, is a process that plays an essential role in cancer development. The evolution of this process depends upon several proangiogenic factors as well as inhibitors of angiogenesis. Coagulation and inflammation also play an important role in tumorigenesis. Their expression is controlled by over- or under-expression of certain genes. The objective of our study was to evaluate the expression, in tissue samples, of a set of six genes involved in tumoral angiogenesis. The study concerned a group of 14 patients with pathologically-confirmed glioblastoma multiforme. Samples of tumoral and peritumoral brain tissue were taken during surgery. We used RT-PCR to evaluate the expression of six genes involved in angiogenesis: VEGF, PDGF, EPCR, TNF, ICAM-1 and CTGF. Gene expression was calculated by comparing the values obtained for the tumoral tissue with those obtained for the peritumoral tissue. Increased transcription of VEGF, PDGF and ICAM-1 genes were observed in glioblastoma tumoral tissues compared with peritumoral brain tissues. Correlations were observed between transcription of the CTGF and TNF genes (rho = 0.54, p-value = 0.05) and PDGF and ICAM-1 genes (rho = 0.54, p-value = 0.05). Under-expression of CTGF, EPCR and TNF genes was observed in glioblastoma tumoral tissue in comparison with peritumoral brain tissue. The association between gene expression and histopathological results (endothelial hyperplasia, coagulation necrosis and ischemic necrosis) was evaluated. No statistically significant associations were observed between gene expression and survival rates.