title: GATA6 is an astrocytoma tumor suppressor gene identified by gene trapping of mouse glioma model.
abstract: Malignant astrocytomas are the most common and lethal adult primary brain tumor. Retroviral gene trapping of nontransformed neonatal astrocytes from a glial fibrillary acidic protein (GFAP):(V12)Ha-Ras murine astrocytoma model led to isolation of the transcription factor Gata6. Loss of Gata6 resulted in enhanced proliferation and transformation of astrocytes. Human malignant astrocytoma cell lines, explant xenografts, and operative specimens demonstrated loss of GATA6 expression. Loss-of-function GATA6 mutations with loss of heterozygosity of the GATA6 locus were found in human malignant astrocytoma specimens but not in lower-grade astrocytomas or normal adult astrocytes. Knockdown of Gata6 expression in (V12)Ha-Ras or p53-/- astrocytes, but not in parental murine or human astrocytes, led to acceleration of tumorgenesis. Knockin GATA6 expression in human malignant astrocytoma cells reduced their tumorgenic growth with decreased VEGF expression. Collectively, these data demonstrate that GATA6, isolated from a murine astrocytoma model, is a novel tumor suppressor gene that is a direct target of mutations during malignant progression of murine and human astrocytomas. This work also demonstrates the utility of random mutagenesis strategies, such as gene trapping, on murine cancer models toward discovery of novel genetic alterations in corresponding human cancers.
authors.affiliation: The Arthur and Sonia Labatts Brain Tumor Research Centre, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada M5G 1X8.
authors.forename: Deepak
authors.initials: D
authors.lastname: Kamnasaran
authors.forename: Baoping
authors.initials: B
authors.lastname: Qian
authors.forename: Cynthia
authors.initials: C
authors.lastname: Hawkins
authors.forename: William L
authors.initials: WL
authors.lastname: Stanford
authors.forename: Abhijit
authors.initials: A
authors.lastname: Guha
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D001254:Astrocytoma / Q000235:genetics*; D004195:Disease Models, Animal; D050993:GATA6 Transcription Factor / Q000235:genetics* / Q000502:physiology; D016147:Genes, Tumor Suppressor; D005910:Glioma / Q000235:genetics*; D006801:Humans; D019656:Loss of Heterozygosity; D051379:Mice; D008822:Mice, Transgenic; D012190:Retroviridae / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D050993:GATA6 Transcription Factor; C494759:GATA6 protein, human; C494760:Gata6 protein, mouse