Alternative Polyadenylation in Triple-Negative Breast Tumors Allows NRAS and c-JUN to Bypass PUMILIO Posttranscriptional Regulation.
Cancer Res
; 76(24): 7231-7241, 2016 12 15.
Article
em En
| MEDLINE
| ID: mdl-27758885
ABSTRACT
Alternative polyadenylation (APA) is a process that changes the posttranscriptional regulation and translation potential of mRNAs via addition or deletion of 3' untranslated region (3' UTR) sequences. To identify posttranscriptional-regulatory events affected by APA in breast tumors, tumor datasets were analyzed for recurrent APA events. Motif mapping of the changed 3' UTR regions found that APA-mediated removal of Pumilio regulatory elements (PRE) was unusually common. Breast tumor subtype-specific APA profiling identified triple-negative breast tumors as having the highest levels of APA. To determine the frequency of these events, an independent cohort of triple-negative breast tumors and normal breast tissue was analyzed for APA. APA-mediated shortening of NRAS and c-JUN was seen frequently, and this correlated with changes in the expression of downstream targets. mRNA stability and luciferase assays demonstrated APA-dependent alterations in RNA and protein levels of affected candidate genes. Examination of clinical parameters of these tumors found those with APA of NRAS and c-JUN to be smaller and less proliferative, but more invasive than non-APA tumors. RT-PCR profiling identified elevated levels of polyadenylation factor CSTF3 in tumors with APA. Overexpression of CSTF3 was common in triple-negative breast cancer cell lines, and elevated CSTF3 levels were sufficient to induce APA of NRAS and c-JUN. Our results support the hypothesis that PRE-containing mRNAs are disproportionately affected by APA, primarily due to high sequence similarity in the motifs utilized by polyadenylation machinery and the PUM complex. Cancer Res; 76(24); 7231-41. ©2016 AACR.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fatores de Transcrição
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Regulação Neoplásica da Expressão Gênica
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Proteínas de Ligação a RNA
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Proteínas Proto-Oncogênicas c-jun
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Neoplasias de Mama Triplo Negativas
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GTP Fosfo-Hidrolases
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Proteínas de Membrana
Tipo de estudo:
Prognostic_studies
Limite:
Female
/
Humans
Idioma:
En
Revista:
Cancer Res
Ano de publicação:
2016
Tipo de documento:
Article