title: Forkhead transcription factor foxq1 promotes epithelial-mesenchymal transition and breast cancer metastasis.
abstract: Epithelial-mesenchymal transition (EMT) promotes cancer invasion and metastasis, but the integrative mechanisms that coordinate these processes are incompletely understood. In this study, we used a cross-species expression profiling strategy in metastatic cell lines of human and mouse origin to identify 22 up-regulated and 12 down-regulated genes that are part of an essential genetic program in metastasis. In particular, we identified a novel function in metastasis that was not previously known for the transcription factor Forkhead Box Q1 (Foxq1). Ectopic expression of Foxq1 increased cell migration and invasion in vitro, enhanced the lung metastatic capabilities of mammary epithelial cells in vivo, and triggered a marked EMT. In contrast, Foxq1 knockdown elicited converse effects on these phenotypes in vitro and in vivo. Neither ectopic expression nor knockdown of Foxq1 significantly affected cell proliferation or colony formation in vitro. Notably, Foxq1 repressed expression of the core EMT regulator E-cadherin by binding to the E-box in its promoter region. Further mechanistic investigation revealed that Foxq1 expression is regulated by TGF-β1, and that Foxq1 knockdown blocked TGF-β1-induced EMT at both morphological and molecular levels. Our findings highlight the feasibility of cross-species expression profiling as a strategy to identify metastasis-related genes, and they reveal that EMT induction is a likely mechanism underlying a novel metastasis-promoting function of Foxq1 defined here in breast cancer.
authors.affiliation: Breast Cancer Biology Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan, USA.
authors.forename: Haijun
authors.initials: H
authors.lastname: Zhang
authors.forename: Fanyan
authors.initials: F
authors.lastname: Meng
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.forename: Feng
authors.initials: F
authors.lastname: Wu
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Ethier
authors.forename: Fred
authors.initials: F
authors.lastname: Miller
authors.forename: Guojun
authors.initials: G
authors.lastname: Wu
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D004285:Dogs; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics* / Q000502:physiology; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009362:Neoplasm Metastasis; D014183:Transplantation, Heterologous
chemical_list: C484579:FOXQ1 protein, human; D051858:Forkhead Transcription Factors