Placenta growth factor (PIGF) mRNA expression in brain tumors

To investigate the relationship between placenta growth factor (PlGF) and b rain tumor angiogenesis, we screened 36 primary and 3 metastatic brain tumo rs. We examined the expression of PlGF mRNA with respect to vasculature of various tumors which was determined by preoperative angiography. The expres sion of genes of the other angiogenic factors, vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) was also tested, a nd compared to that of PlGF. The primary tumors consisted of 16 meningiomas , 7 gliomas, 7 schwannomas, 4 pituitary adenomas, 1 germinoma, and 1 chorio carcinoma. Using a quantitative reverse transcription-polymerase chain reac tion, the mRNA for PlGF(149) and PlGF(170) were detected in 25 out of 39 (6 4.1%) brain tumors. In primary brain tumors, PlGF mRNA eras expressed in al l the hypervascular tumors, but only in 5 of 16 hypovascular tumors (31.3%) . None of the 3 metastatic hypervascular tumors expressed PIGF mRNA. The VE GF and bFGF mRNA expression was both detected in 87.2% of the tumors examin ed. We conducted hypoxic experiments with cultured U-251MG human glioma cel ls to determine the mechanism of PlGF gene regulation. As the atmospheric o xygen concentration was decreased, the PlGF mRNA level in the U-251MG cells was markedly increased. These results suggest that PlGF may contribute to the pathogenesis of brain tumor angiogenesis.