MFTZ-1,a novel topoisomerase Ⅱ poison,reduces constitutive and inducible HIF-1α accumulation and VEGF secretion independent of its Top2 inhibition

【作者】 代梅； 缪泽鸿； 任萱； 童林江； 杨娜； 李婷； 林莉萍； 沈岳茅； 丁健；

【机构】 中国科学院上海药物研究所； 中国科学院研究生院； 中国科学院昆明植物研究所；

【摘要】 <正>Purpose:The macrolide compound MFTZ-1 has been identified as a novel topoisomeraseⅡ(Top2) inhibitor with potent in vitro and in vivo anti-tumor activities.This study was to further examine its effects on hypoxia-inducible factor-1α(HIF-1α) accumulation,vascular endothelial growth factor(VEGF) secretion and the possible mechanisms.Experimental Design: Western blotting,reverse transcription-PCR,real time-PCR,ELISA and small interference RNA (siRNA) analyses were used to investigate the impact of MFTZ-1 on HIF-1αaccumulation and on VEGF secretion and the possible mechanism.Angiogenesis inhibition was assessed by the human umbilical vascular cell(HUVEC) migration and tube formation.Results:MFTZ-1 reduced HIF-1αaccumulation driven by hypoxia or growth factors in human cancer cells.However, MFTZ-1 did not affect protein degradation or mRNA level of HIF-1α.By contrast,MFTZ-1 apparently inhibited both phosphatidylinositol-3-kinase(PI3K-Akt) and p42/p44 mitogen-activated protein kinase(MAPK) pathways.Further studies revealed that MFTZ-1 abrogated the HIF-1α-driven increase of VEGF mRNA and secretion.MFTZ-1 also lowered the basal level in VEGF secretion.The results reveal an important feature that MFTZ-1 can reduce VEGF secretion in a HIF-1α-dependent and HIF-1α-independent way.Moreover,MFTZ-1 disrupted tube formation of HUVEC stimulated by hypoxia or serum,and inhibited HUVEC migration and microvessel outgrowth from rat aortic ring.Furthermore,we showed that MFTZ-1 affected HIF-1αaccumulation and HUVECs tube formation independent of its Top2 inhibition. Conclusion:Our data collectively reveal that MFTZ-1 reduces constitutive and inducible HIF-1αaccumulation and VEGF secretion via PI3K-Akt and MAPK pathways,eliciting antiangiogenesis independently of its Top2 inhibition.更多还原

【Abstract】 Purpose:The macrolide compound MFTZ-1 has been identified as a novel topoisomeraseⅡ(Top2) inhibitor with potent in vitro and in vivo anti-tumor activities.This study was to further examine its effects on hypoxia-inducible factor-1α(HIF-1α) accumulation,vascular endothelial growth factor(VEGF) secretion and the possible mechanisms.Experimental Design: Western blotting,reverse transcription-PCR,real time-PCR,ELISA and small interference RNA (siRNA) analyses were used to investigate the impact of MFTZ-1 on HIF-1αaccumulation and on VEGF secretion and the possible mechanism.Angiogenesis inhibition was assessed by the human umbilical vascular cell(HUVEC) migration and tube formation.Results:MFTZ-1 reduced HIF-1αaccumulation driven by hypoxia or growth factors in human cancer cells.However, MFTZ-1 did not affect protein degradation or mRNA level of HIF-1α.By contrast,MFTZ-1 apparently inhibited both phosphatidylinositol-3-kinase(PI3K-Akt) and p42/p44 mitogen-activated protein kinase(MAPK) pathways.Further studies revealed that MFTZ-1 abrogated the HIF-1α-driven increase of VEGF mRNA and secretion.MFTZ-1 also lowered the basal level in VEGF secretion.The results reveal an important feature that MFTZ-1 can reduce VEGF secretion in a HIF-1α-dependent and HIF-1α-independent way.Moreover,MFTZ-1 disrupted tube formation of HUVEC stimulated by hypoxia or serum,and inhibited HUVEC migration and microvessel outgrowth from rat aortic ring.Furthermore,we showed that MFTZ-1 affected HIF-1αaccumulation and HUVECs tube formation independent of its Top2 inhibition. Conclusion:Our data collectively reveal that MFTZ-1 reduces constitutive and inducible HIF-1αaccumulation and VEGF secretion via PI3K-Akt and MAPK pathways,eliciting antiangiogenesis independently of its Top2 inhibition.更多还原