Curcumin Suppresses Tumor Growth and Angiogenesis in Human Glioma Cells Through Modulation of Vascular Endothelial Growth Factor/ Angiopoietin-2/Thrombospondin-1 Signaling

Purpose: To investigate the effect of curcumin on tumor growth and angiogenesis of human gliomas and identify the underlying molecular mechanisms. Methods: A mouse xenograft glioma model was established by subcutaneously inoculating tumor cell aggregates derived from the U87 cell line. Mice were treated with 0.01ml/g body weight of curcumin or saline. Tumor volume was measured. Microvessel density was assessed by CD34 immunostaining, and angiogenesis by immunohistochemical staining of vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2) and thrombospondin 1 (TSP-1). Results: At 28 days after treatment, tumor weights in the curcumin-treated group were much smaller than in the control group (0.23±0.11g vs 0.44±0.15g#140;p#156;0.05), resulting in a 45.8% inhibition of tumor growth. Curcumin also markedly inhibited microvessel density. Expression of VEGF and Ang-2 was inhibited by curcumin, whereas TSP-1 expression was up-regulated. Conclusion: This study shows that curcumin inhibits tumor growth by inhibiting VEGF/Ang-2/TSP-1- mediated angiogenesis in a xenograft glioma mouse model.