Tumor suppressor properties of the splicing regulatory factor RBM10

RBM10 is an RNA binding protein and alternative splicing regulator frequently mutated in lung adenocarcinomas. Recent results indicate that RBM10 inhibits proliferation of lung cancer cells by promoting skipping of exon 9 of the gene NUMB, a frequent alternative splicing change in lung cancer genera...

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Detalles Bibliográficos
Autores: Hernández, Jordi, Bechara, Elias, Schlesinger, Doerte, Delgado Blanco, Javier, Serrano Pubull, Luis, 1982-, Valcárcel, J. (Juan)
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2016
País:España
Institución:Universitat Pompeu Fabra
Repositorio:Repositorio Digital de la UPF
OAI Identifier:oai:repositori.upf.edu:10230/26874
Acceso en línea:http://hdl.handle.net/10230/26874
http://dx.doi.org/10.1080/15476286.2016.1144004
Access Level:acceso abierto
Palabra clave:Pulmons -- Càncer
Lung cancer
NUMB
Notch
RBM10
Splicing
Descripción
Sumario:RBM10 is an RNA binding protein and alternative splicing regulator frequently mutated in lung adenocarcinomas. Recent results indicate that RBM10 inhibits proliferation of lung cancer cells by promoting skipping of exon 9 of the gene NUMB, a frequent alternative splicing change in lung cancer generating a negative regulator of Notch signaling. Complementing these observations, we show that knock down of RBM10 in human cancer cells enhances growth of mouse tumor xenografts, confirming that RBM10 acts as a tumor suppressor, while knock down of an oncogenic mutant version of RBM10 reduces xenograft tumor growth. A RBM10 mutation found in lung cancer cells, V354E, disrupts RBM10-mediated regulation of NUMB alternative splicing, inducing the cell proliferation-promoting isoform. We now show that 2 natural RBM10 isoforms that differ by the presence or absence of V354 in the second RNA Recognition Motif (RRM2), display similar regulatory effects on NUMB alternative splicing, suggesting that V354E actively disrupts RBM10 activity. Structural modeling localizes V354 in the outside surface of one α-helix opposite to the RNA binding surface of RBM10, and we show that the mutation does not compromise binding of the RRM2 domain to NUMB RNA regulatory sequences. We further show that other RBM10 mutations found in lung adenocarcinomas also compromise regulation of NUMB exon 9. Collectively, our previous and current results reveal that RBM10 is a tumor suppressor that represses Notch signaling and cell proliferation through the regulation of NUMB alternative splicing.