The Mechanism Of Fullerenol C₆₀（OH）₂₂ On Angiogenesis

Background: Angiogenesis plays a crucial role in solid tumor growth andmetastasis, thus anti-angiogenesis therapy becomes an important method foroncotherapy. C60(OH)22nanoparticle has shown anti-tumor ability in vivo throughanti-angiogenesis and immunoregulation effect, while without obvious cytotoxicity invitro. However the mechanism of its anti-angiogenesis effect remains unclear.Previous studies demonstrate the C60derivatives can regulate histone deacetylase, andhistone deacetylase inhibitors have shown anti-angiogenesis activity throughinactivation of HIF-1α-VEGF signal in various tumors. The aim of this study is toexplore the anti-angiogenesis effect of C60(OH)22and further to understandmechanism.Materials and Methods: Human umbilical vein endothelial cells are treated withC60(OH)22or PBS (negative control). Cell viability is detected by MTT assay.Cellinvasion is detected by transwell assay. Tubulogenesis is evaluated by tube formationassay. The level of intracellular reactive oxygen species, the expression ofHDAC1,HDAC2, HIF-1α,VEGF,RECK and the enzymatic activity of MMP2,MMP9are measured using fluorescence microscope，western blot and gelatin zymographyassay respectively. Knockdown of HDAC1or HDAC2is performed to explorewhether C60(OH)22regulates angiogenesis by down-regulation of HDAC1or HDAC2.Matrigel plug model is employed to evaluate the anti-angiogenesis effect of C60(OH)22in vivo. Results: C60(OH)22inhibits cell invasion and tubulogenesis without significantcytotoxicity. Intracellular reactive oxygen species, the expression ofHDAC1,HDAC2,HIF-1α,VEGF and the enzyme activity of MMP2, MMP9aredecreased, while the expression of RECK is increased after C60(OH)22treatment.Knockdown of HDAC1or HDAC2both can inhibit cell invasion and tubulogenesis,decrease intracellular reactive oxygen species and the expression of HIF-1α and VEGFas well as the enzyme activity of MMP2,MMP9,while increase the expression ofRECK. The anti-angiogenesis effect of C60(OH)22is further validated in vivo.Conclusions: C60(OH)22suppresses angiogenesis through its inhibition onHDAC1and HDAC2.