BRG1 loss in MiaPaCa2 cells induces an altered cellular morphology and disruption in the organization of the actin cytoskeleton

Rosson, Gary B.; Bartlett, Christopher S.; Reed, William; Weissman, Bernard E.

doi:10.1002/jcp.20397

Cited by 40 publications

(39 citation statements)

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“…In that respect, it is worth mentioning that the SWI/SNF ATPase subunit has already been involved in the regulation of cell morphology and cytoskeleton organization (35,36). Indeed, NIH-3T3 cells expressing dominant-negative ATPase-deficient BRG1 exhibit a larger size and attachment area (35), an observation in agreement with the increased size of hSNF5/INI1-deficient MRT, 293T, or MCF7 cells.…”

Section: Discussionsupporting

confidence: 67%

“…Indeed, NIH-3T3 cells expressing dominant-negative ATPase-deficient BRG1 exhibit a larger size and attachment area (35), an observation in agreement with the increased size of hSNF5/INI1-deficient MRT, 293T, or MCF7 cells. Similarly, pancreatic adenocarcinoma cells, in which the expression of BRG1 was inhibited, exhibit a change in hSNF5/INI1 Inhibits Migration www.aacrjournals.org morphology and alterations of the actin cytoskeleton organization (36). Although they were not studied in the aforementioned reports, it will be of strong interest to document whether RhoA activation and altered cell motility are common features of the various systems with loss-of-function alterations of subunits of the SWI/ SNF complex.…”

Section: Discussionmentioning

confidence: 99%

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RhoA-Dependent Regulation of Cell Migration by the Tumor Suppressor hSNF5/INI1

2008

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Malignant rhabdoid tumors (MRT) are extremely aggressive pediatric tumors caused by the inactivation of the hSNF5/INI1 tumor suppressor gene, which encodes a core member of the SWI/SNF chromatin remodeling complex. Roles for hSNF5/ INI1 in cell cycle and differentiation have been documented. Based on the observation that MRTs are highly invasive, we investigated a role for hSNF5/INI1 in cell migration. MRT cell lines exhibit high migration properties that are dramatically reduced upon hSNF5/INI1 expression. This effect is associated with the disorganization of the actin stress fiber network and is mediated by the inhibition of the activity of the small GTPase RhoA, through a nuclear, SWI/SNF-dependent transcriptional mechanism. We further show that the knockdown of hSNF5/INI1 in epithelial 293T or MCF7 cells results in increased cell size, loss of cell-cell adhesions, and enhanced migration, associated with an increased RhoA activity. Finally, we show that the SNF5 homology domain is required for hSNF5/INI1-mediated inhibition of migration, and that a missense mutation (S284L) associated with cancer is sufficient to impair hSNF5/INI1 function in migration. We conclude that the inhibition of migration is another crucial tumor suppressor function of hSNF5/INI1, in addition to its previously described functions in proliferation and differentiation, and that its loss-of-function in MRTs may account for the high invasiveness and metastatic potential of these tumors. [Cancer Res 2008;68(15):6154-61]

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Section: Discussionsupporting

confidence: 67%

Section: Discussionmentioning

confidence: 99%

RhoA-Dependent Regulation of Cell Migration by the Tumor Suppressor hSNF5/INI1

2008

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“…Indeed, previous studies have shown that BRG1 loss induces an altered cellular morphology and disruption in the organization of the actin cytoskeleton (20), and mutations in the SWI/SNF complex resulted in changes in cell size and attachment area (21). Our results suggest that ADNP functionality plays a role in these changes.…”

Section: Discussionsupporting

confidence: 59%

Activity-dependent Neuroprotective Protein Constitutes a Novel Element in the SWI/SNF Chromatin Remodeling Complex

Mandel¹,

Gozes

2007

Journal of Biological Chemistry

127

111

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Complete deficiency in activity-dependent neuroprotective protein (ADNP), a heterochromatin 1-binding protein, results in dramatic changes in gene expression, neural tube closure defects, and death at gestation day 9 in mice. To further understand the cellular roles played by ADNP, the HEK293 human embryonic kidney cell line that allows efficient transfection with recombinant DNA was used as a model for the identification of ADNP-interacting proteins. Recombinant green fluorescent protein (GFP)-ADNP was localized to cell nuclei. When nuclear extracts were subjected to immunoprecipitation with specific GFP antibodies followed by polyacrylamide gel electrophoresis, several minor protein bands were observed in addition to GFP-ADNP. In-gel protein digests followed by mass spectrometry identified BRG1, BAF250a, and BAF170, all components of the SWI/SNF (mating type switching/sucrose nonfermenting) chromatin remodeling complex, as proteins that co-immunoprecipitate with ADNP. These results were verified utilizing BRG1 antibodies. ADNP short hairpin RNA down-regulation resulted in microtubule reorganization and changes in cell morphology including reduction in cell process formation and cell number. These morphological changes are closely associated with the SWI/SNF complex multifunctionality. Taken together, the current study uncovers a molecular basis for the essential function of the ADNP gene and protein.Activity-dependent neuroprotective protein (ADNP 3 (1)) was originally discovered as a gene product associated with neuroprotection/neuroglia interactions (2). ADNP immunoreactivity was shown to localize to the astrocyte nucleus as well as to the cytoplasm and to the extracellular space, where the protein enhances neuronal survival (3, 4). Further studies suggested very high gene conservation in mammals including humans, increased expression in malignant cells, and close association with cellular survival (5). In the mature brain, ADNP expression was modulated by injury, suggesting a potential protective effect for the protein in vivo (6, 7). Additionally, ADNP expression shows sexual dichotomy and is modulated during the estrous cycle in the arcuate nucleus of the hypothalamus (8) and in the vagina (9), suggesting a potential neurotrophic/plasticity-associated effect for the protein.Importantly, complete deficiency in ADNP results in neural tube closure defects and death at gestation day 9 in mice (10). ADNP-deficient embryos exhibit dramatic increases in gene transcripts associated with lipid metabolism coupled to a reduction in organogenesis/neurogenesis related transcripts (11). In pluripotent P19 cells, ADNP was shown to interact with specific chromatin regions in the neuro-differentiated state, which was associated with binding to heterochromatin protein 1 (11). To further understand ADNP function, the HEK293 human embryonic kidney cell line that allows efficient transfection with recombinant DNA was used as a model for the identification of ADNP-interacting proteins and cellular function, suggesting that ADN...

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“…4 By knocking down BRG1 expression in the BRM deficient MiaPaca2 cell line using shRNA, they observed that loss of SWI/SNF complex activity resulted in a dramatic change in cellular morphology accompanied by altered actin cytoskeletal organization. 5 Similar observations were made in a HeLa cell derivative D98oR. Knockdown of either BRM or BRG1 alone by stable expression of RNA did not apparently affect cellular morphology.…”

Section: Genetic and Epigenetic Determinants Of Tumor Progressionsupporting

confidence: 67%