BRCA1 and p53 regulate critical prostate cancer pathways

• Autores: De Luca, P.; Moiola, C.P.; Zalazar, F.; Gardner, K.; Vazquez, E.S.; De Siervi, A.
• Año de publicación: 2013
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Prostate Cancer Prostatic Dis. 2013;16(3):233-238
• Materia: BRCA1; DNA damage; GADD153; p53; beta catenin; Bloom syndrome helicase; BRCA1 protein; BRCA2 protein; cyclin D1; cyclin dependent kinase inhibitor 1; fibronectin; growth arrest and DNA damage inducible protein 153; luciferase; protein p53; protein Patched 1; sonic hedgehog protein; transcription factor Gli1; transcription factor Slug; transcription factor Snail; uvomorulin; vimentin; actin B gene; animal experiment; animal model; animal tissue; article; beta catenin gene; BLM gene; CCNB2 gene; cell cycle regulation; cell strain LNCaP; chromatin immunoprecipitation; controlled study; Cyclin D1 gene; DDB2 gene; DNA damage; E cadherin gene; enzyme assay; epithelial mesenchymal transition; FEN1 gene; fibronectin gene; GADD153 gene; Gadd45a gene; gene; gene expression; GLI1 gene; H3F3B gene; in vivo study; male; mouse; nonhuman; p21 WAF1 CIP1 gene; patch1 gene; priority journal; prostate cancer; protein expression; quantitative analysis; reverse transcription polymerase chain reaction; SHH gene; Slug gene; Snail gene; transcription regulation; tumor suppressor gene; Vimentin gene; Western blotting; Animals; BRCA1 Protein; Cell Cycle; Cell Line, Tumor; DNA Damage; Hedgehogs; Heterografts; Humans; Male; Mice; Prostatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Transcription Factor CHOP; Transcription, Genetic; Tumor Suppressor Protein p53
• Institución: Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales

Background:Loss or mutations of the BRCA1 gene are associated with increased risk of breast and ovarian cancers and with prostate cancer (PCa) aggressiveness. Previously, we identified GADD153 as a target of BRCA1 protein, which increases doxorubicin sensitivity in human p53 -/- PCa cells (PC3). Considering that p53 is a crucial target in cancer therapy, in this work we investigated p53 role in the regulation of transcription of GADD153.Methods:We performed reverse transcription quantitative PCR (RT-qPCR), western blot and luciferase assays to analyze GADD153 and/or BRCA1 expression in response to ultraviolet or doxorubicin exposure in PC3 p53 stable-transfected cells and LNCaP (p53+/+) cells. BRCA1 protein recruitment to GADD153 promoter was studied by chromatin immunoprecipitation-qPCR. To assess expression of BRCA1 and/or p53 target genes, we used a panel of stable-transfected PCa cell lines. We finally analyzed these genes in vivo using BRCA1-depleted PCa xenograft models.Results:We found that GADD153 was highly induced by doxorubicin in PC3 cells; however, this response was totally abolished in LNCaP (p53wt) and in p53-restituted PC3 cells. Furthermore, BRCA1 protein associates to GADD153 promoter after DNA damage in the presence of p53. Additionally, we demonstrated that BRCA1 and/or p53 modulate genes involved in DNA damage and cell cycle regulation (cyclin D1, BLM, BRCA2, DDB2, p21 WAF1/CIP1, H3F3B, GADD153, GADD45A, FEN1, CCNB2), EMT (E-cadherin, β-catenin, vimentin, fibronectin, slug, snail) and Hedgehog pathways (SHH, IHH, DHH, Gli1, PATCH1). Furthermore, xenograft studies demonstrated that BRCA1 knockdown in PC3 cells increased tumor growth and modulated these genes in vivo.Conclusions:Although BRCA1 induces GADD153 in a p53 independent manner, p53 abolished GADD153 induction in response to DNA damage. In addition, several important PCa targets are modulated by BRCA1 and p53. Altogether, these data might be important to understand the therapy response of PCa patients.© 2013 Macmillan Publishers Limited All rights reserved.
Fil:De Luca, P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Moiola, C.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Vazquez, E.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:De Siervi, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.