title: In vivo dynamics and distinct functions of hypoxia in primary tumor growth and organotropic metastasis of breast cancer.
abstract: Tumor hypoxia is known to activate angiogenesis, anaerobic glycolysis, invasion, and metastasis. However, a comparative analysis of the potentially distinct functions of hypoxia in primary tumor growth and organ-specific metastasis has not been reported. Here, we show distinct hypoxia kinetics in tumors generated by the MDA-MB-231 breast cancer sublines with characteristically different primary tumor growth rates and organotropic metastasis potentials. Hypoxia-induced angiogenesis promotes both primary tumor growth and lung metastasis but is nonessential for bone metastasis. Microarray profiling revealed that hypoxia enhances the expression of a significant number of genes in the lung metastasis signature, but only activates a few bone metastasis genes, among which DUSP1 was functionally validated in this study. Despite the different mechanisms by which hypoxia promotes organ-specific metastasis, inhibition of HIF-1alpha with a dominant-negative form of HIF-1alpha or 2-methoxyestradiol reduced metastasis to both lung and bone. Consistent with the extensive functional overlap of hypoxia in promoting primary tumor growth and lung metastasis, a 45-gene hypoxia response signature efficiently stratifies breast cancer patients with low or high risks of lung metastasis, but not for bone metastasis. Our study shows distinct functions of hypoxia in regulating angiogenesis and metastasis in different organ microenvironments and establishes HIF-1alpha as a promising target for controlling organotropic metastasis of breast cancer.
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Lu
authors.forename: Carol H
authors.initials: CH
authors.lastname: Yan
authors.forename: Min
authors.initials: M
authors.lastname: Yuan
authors.forename: Yong
authors.initials: Y
authors.lastname: Wei
authors.forename: Guohong
authors.initials: G
authors.lastname: Hu
authors.forename: Yibin
authors.initials: Y
authors.lastname: Kang
mesh_terms: D000077584:2-Methoxyestradiol; D000818:Animals; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001859:Bone Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000556:secondary*; D001943:Breast Neoplasms / Q000098:blood supply / Q000473:pathology*; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D020869:Gene Expression Profiling; D005799:Genes, Dominant; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000556:secondary*; D051379:Mice; D009389:Neovascularization, Pathologic / Q000503:physiopathology*; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D015996:Survival Rate; D050257:Tubulin Modulators / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: D014408:Biomarkers, Tumor; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D050257:Tubulin Modulators; D004958:Estradiol; D000077584:2-Methoxyestradiol