An inhibitor of HIF-αsubunit expression suppresses hypoxiainduced dedifferentiation of human NSCLC into cancer stem cell-like cells

• 作者: Hideko Nagasawa Hitoshi Hori Keizo Takenaga Miho Akimoto Yoshihiro Uto Yoshio Honma
• 来源期刊: 世界医学遗传学杂志
• 学科: 医学
• 关键词: Non-small cell lung CANCER Tumor microenvironment HYPOXIA Hypoxia-inducible FACTOR Differentiation CANCER stem CELLS Hypoxia-inducible FACTOR INHIBITOR
• 年，卷（期）: sjyxycxzz_2013,（4）
• 页码范围: 41-54
• 页数: 14页
• 分类号: R457

摘要

ferentiation 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%O2)or hypoxic(4%or 1%O2)conditions.The expression of the following genes were examined by reverse transcription-polymerase chain reaction,Western blotting and/or immunofluorescence:HIF-1αand HIF-2αsubunits;differentiation marker genes,namely surfactant protein C(SP-C)(typeⅡalveolar cell marker),CC10(typeⅠalveolar cell marker)and aquaporin 5(AQP5)(Clara cell marker);and stem cell-associated genes,namely CD133,OCT4,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-1αsubunit 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 th