microRNAs 424 and 503 are mediators of the anti-proliferative and anti-invasive action of the thyroid hormone receptor beta

The thyroid hormone receptors (TRs) mediate tumor suppressive effects in hepatocarcinoma and breast cancer cells. Here we show that incubation of hepatocarcinoma SK-hep1 cells expressing TRb with the thyroid hormone T3 induces transcription of the polycistronic message coding for microRNAs 424 and 5...

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Detalles Bibliográficos
Autores: Ruiz Llorente, Lidia, Ardila González, Soraya, Fanjul, Luisa F., Martínez Iglesias, Olaia, Aranda, Ana
Tipo de recurso: artículo
Fecha de publicación:2014
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/662320
Acceso en línea:http://hdl.handle.net/10486/662320
Access Level:acceso abierto
Palabra clave:Thyroid hormone receptor
MicroRNA-424
MicroRNA-503
Proliferation
Invasion
Hepatocarcinoma and breast cancer cells
Biología y Biomedicina / Biología
Descripción
Sumario:The thyroid hormone receptors (TRs) mediate tumor suppressive effects in hepatocarcinoma and breast cancer cells. Here we show that incubation of hepatocarcinoma SK-hep1 cells expressing TRb with the thyroid hormone T3 induces transcription of the polycistronic message coding for microRNAs 424 and 503. TRb binds to the promoter region of these miRNAs and T3 induces an exchange of corepressors and coactivators inducing histone acetylation and transcriptional stimulation. We have validated cell cycle components as targets of these miRNAs. Overexpression of miR-424 mimicked the repressive effect of T3 on cell proliferation, growth in suspension, migration and invasion. Knockdown of miR-424 or miR-503 reduced the inhibitory effect of the hormone. T3 increased miR-424 and miR-503 in breast cancer cells expressing TRb, and this induction is also involved in the antiinvasive effects of the hormone. Furthermore, miR-424 or miR-503 depletion enhanced extravasation to the lungs of hepatocarcinoma cells injected in the tail vein of mice. The levels of these miRNAs were reduced in xenograft tumors formed in hypothyroid nude mice that are more invasive. Therefore, miR-424 or miR-503 mediate antiproliferative and anti-invasive actions of TRb both in cultured cells and in vivo