Protein-protein interactions are vital for a wide range of biological processes.The interactions between the hypoxia-inducible factor and von Hippel Lindau(VHL)are attractive drug targets for ischemic heart disease.In...Protein-protein interactions are vital for a wide range of biological processes.The interactions between the hypoxia-inducible factor and von Hippel Lindau(VHL)are attractive drug targets for ischemic heart disease.In order to disrupt this interaction,the strategy to target VHL binding site using a hydroxyproline-like(pro-like)small molecule has been reported.In this study,we focused on the inhibition mechanism between the pro-like inhibitors and the VHL protein,which were investigated via molecular dynamics simulations and binding free energy calculations.It was found that pro-like inhibitors showed a strong binding affinity toward VHL.Binding free energy calculations and free energy decompositions suggested that the modification of various regions of pro-like inhibitors may provide useful information for future drug design.展开更多
AIM:To investigate whether hypoxia induces dedifferentiation of non-small cell lung cancer(NSCLC) cells and whether a hypoxia-inducible factor(HIF) inhibitor is able to suppress the process.METHODS:Human lung adenocar...AIM:To investigate whether hypoxia induces dedifferentiation of non-small cell lung cancer(NSCLC) cells and whether a hypoxia-inducible factor(HIF) inhibitor is able to suppress the process.METHODS:Human lung adenocarcinoma A549 cells and squamous carcinoma QG56 cells were cultured under normoxic(21%O_2) or hypoxic(4%or 1%O_2) conditions.The expression of the following genes were examined by reverse transcription-polymerase chain reaction,Western blotting and/or immunofluorescence:HIF-1α and HIF-2αsubunits;differentiation marker genes,namely surfactant protein C(SP-C)(type Ⅱ alveolar cell marker),CC10(type I alveolar cell marker) and aquaporin 5(AQP5)(Clara cell marker);and stem cell-associated genes,namely CD133,0CT4,and Musashi-1(MSI1).The tumor sphere-forming ability of the cells was evaluated by culturing them in serum-free growth factor-rich medium containing epidermal growth factor(EGF) and fibroblast growth factor(FGF).CD133 expression in hypoxic regions in A549 tumors was examined by double-immunostaining of tissue cryosections with an anti-2-nitroimidazole EF5 antibody and an anti-CD133 antibody.The metastatic ability of A549 cells was examined macroscopically and histologically after injecting them into the tail vein of immunocompromised mice.RESULTS:A549 cells primarily expressed SP-C,and QG56 cells expressed CC10 and AQP5.Exposure of A549 cells to hypoxia resulted in a marked downregulation of SP-C and upregulation of CD133,OCT4,and MSI1 in a time-dependent manner.Moreover,hypoxia mimetics,namely desferrioxamine and cobalt chloride,elicited similar effects.Ectopic expression of the constitutively active HIF-la subunit also caused the downregulation of SP-C and upregulation of CD133 and MSI1 but not OCT4,which is a direct target of HIF-2.Hypoxia enhanced the sphere-forming activity of A549 cells in serum-free medium containing EGF and FGF.Similarly,hypoxia downregulated the expression of CC10 and AQP5 genes and upregulated CD133,OCT4,and MSI1 genes in QG56 cells.TX-402(3-amino-2-quinoxalinecarbonitrile 1,4-dioxide),which is a small molecule inhibitor of the expression of HIF-1α and HIF-2αsubunits under hypoxic conditions,inhibited the upregulation of SP-C'and hypoxia-induced down-regulation of CD133,OCT4,and MSI1.Notably,TX-402 significantly suppressed the hypoxia-enhanced lung-colonizing ability of A549 cells.CONCLUSION:Hypoxia induces the de-differentiation of NSCLC cells into cancer stem cell-like cells,and HIF inhibitors are promising agents to prevent this process.展开更多
目的研究缺氧诱导因子抑制剂对卵巢切除(ovariectomized,OVX)雌性Sprague-Dawley大鼠的治疗效果,比较缺氧诱导因子抑制剂对骨密度的影响。方法在大鼠卵巢切除12周后,使用缺氧诱导因子抑制剂进行治疗。治疗8周后,在实验结束时将大鼠进行...目的研究缺氧诱导因子抑制剂对卵巢切除(ovariectomized,OVX)雌性Sprague-Dawley大鼠的治疗效果,比较缺氧诱导因子抑制剂对骨密度的影响。方法在大鼠卵巢切除12周后,使用缺氧诱导因子抑制剂进行治疗。治疗8周后,在实验结束时将大鼠进行安乐死处理,获取大鼠血清、股骨和胫骨。通过生物力学测试,Micro-CT扫描和血清生化分析进行评估。结果与未给药的OVX大鼠相比,缺氧诱导因子抑制剂的全身给药显著降低了骨代谢指标Ⅰ型前胶原氨基末端前肽(type I collagen N terminal peptide,PINP)和Ⅰ型胶原羧基端肽(type I collagen carboxy-terminal peptide,CTX-I),增加了大鼠胫骨骨密度(bone mineral density, BMD),增强了股骨极限载荷、能量和刚度,差异比较有统计学意义(P<0.05)。结论缺氧诱导因子抑制剂能有效改善OVX诱导的骨质疏松症。展开更多
基金supported by the National Natural Science Foundation of China(No.21973064)the Post-Doctor Research Project,West China Hospital,Sichuan University(No.2021HXBH017)。
文摘Protein-protein interactions are vital for a wide range of biological processes.The interactions between the hypoxia-inducible factor and von Hippel Lindau(VHL)are attractive drug targets for ischemic heart disease.In order to disrupt this interaction,the strategy to target VHL binding site using a hydroxyproline-like(pro-like)small molecule has been reported.In this study,we focused on the inhibition mechanism between the pro-like inhibitors and the VHL protein,which were investigated via molecular dynamics simulations and binding free energy calculations.It was found that pro-like inhibitors showed a strong binding affinity toward VHL.Binding free energy calculations and free energy decompositions suggested that the modification of various regions of pro-like inhibitors may provide useful information for future drug design.
基金Supported by Grant-in-Aid from the Ministry of Education,Culture,Sports,Science and Technology,(No.18590280)the Foundation for the Promotion of Cancer Research in Japan+1 种基金Grant-in-Aid for Japan Arteriosclerosis Research FoundationShimane University"S-TAKUMI Medical Nanotechnology"Project
文摘AIM:To investigate whether hypoxia induces dedifferentiation of non-small cell lung cancer(NSCLC) cells and whether a hypoxia-inducible factor(HIF) inhibitor is able to suppress the process.METHODS:Human lung adenocarcinoma A549 cells and squamous carcinoma QG56 cells were cultured under normoxic(21%O_2) or hypoxic(4%or 1%O_2) conditions.The expression of the following genes were examined by reverse transcription-polymerase chain reaction,Western blotting and/or immunofluorescence:HIF-1α and HIF-2αsubunits;differentiation marker genes,namely surfactant protein C(SP-C)(type Ⅱ alveolar cell marker),CC10(type I alveolar cell marker) and aquaporin 5(AQP5)(Clara cell marker);and stem cell-associated genes,namely CD133,0CT4,and Musashi-1(MSI1).The tumor sphere-forming ability of the cells was evaluated by culturing them in serum-free growth factor-rich medium containing epidermal growth factor(EGF) and fibroblast growth factor(FGF).CD133 expression in hypoxic regions in A549 tumors was examined by double-immunostaining of tissue cryosections with an anti-2-nitroimidazole EF5 antibody and an anti-CD133 antibody.The metastatic ability of A549 cells was examined macroscopically and histologically after injecting them into the tail vein of immunocompromised mice.RESULTS:A549 cells primarily expressed SP-C,and QG56 cells expressed CC10 and AQP5.Exposure of A549 cells to hypoxia resulted in a marked downregulation of SP-C and upregulation of CD133,OCT4,and MSI1 in a time-dependent manner.Moreover,hypoxia mimetics,namely desferrioxamine and cobalt chloride,elicited similar effects.Ectopic expression of the constitutively active HIF-la subunit also caused the downregulation of SP-C and upregulation of CD133 and MSI1 but not OCT4,which is a direct target of HIF-2.Hypoxia enhanced the sphere-forming activity of A549 cells in serum-free medium containing EGF and FGF.Similarly,hypoxia downregulated the expression of CC10 and AQP5 genes and upregulated CD133,OCT4,and MSI1 genes in QG56 cells.TX-402(3-amino-2-quinoxalinecarbonitrile 1,4-dioxide),which is a small molecule inhibitor of the expression of HIF-1α and HIF-2αsubunits under hypoxic conditions,inhibited the upregulation of SP-C'and hypoxia-induced down-regulation of CD133,OCT4,and MSI1.Notably,TX-402 significantly suppressed the hypoxia-enhanced lung-colonizing ability of A549 cells.CONCLUSION:Hypoxia induces the de-differentiation of NSCLC cells into cancer stem cell-like cells,and HIF inhibitors are promising agents to prevent this process.
文摘目的研究缺氧诱导因子抑制剂对卵巢切除(ovariectomized,OVX)雌性Sprague-Dawley大鼠的治疗效果,比较缺氧诱导因子抑制剂对骨密度的影响。方法在大鼠卵巢切除12周后,使用缺氧诱导因子抑制剂进行治疗。治疗8周后,在实验结束时将大鼠进行安乐死处理,获取大鼠血清、股骨和胫骨。通过生物力学测试,Micro-CT扫描和血清生化分析进行评估。结果与未给药的OVX大鼠相比,缺氧诱导因子抑制剂的全身给药显著降低了骨代谢指标Ⅰ型前胶原氨基末端前肽(type I collagen N terminal peptide,PINP)和Ⅰ型胶原羧基端肽(type I collagen carboxy-terminal peptide,CTX-I),增加了大鼠胫骨骨密度(bone mineral density, BMD),增强了股骨极限载荷、能量和刚度,差异比较有统计学意义(P<0.05)。结论缺氧诱导因子抑制剂能有效改善OVX诱导的骨质疏松症。
