Wnt1-induced mammary tumor from Rarb KO mice vs. those from Rarb wt (control)
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ABSTRACT: Previously we have demonstrated that inactivation of retinoic acid receptor beta (Rarb) in the mouse results in a protective effect against ErbB2-induced mammary gland tumorigenesis although Rarb has been reported as a tumor suppressor before. In the current study, we further confirmed that ablation of Rarb has a very similar impact on Wnt1-induced mammary gland tumorigenesis as those on ErbB2-induced mammary gland tumorigenesis. Nevertheless, the mechanisms by which Rarb confers its effects on tumor progression is quite different although both involving in tumor microenvironment (TME) remodeling. In the Wnt1 tumors, ectopic wnt1 produced by malignant luminal cells activates nearby stromal cells by a paracrine manner. In return, the stromal cells secreted IGF1 to regulate the growth of tumor cells. There is a need of Rarb expression in this interaction. Deletion of Rarb inhibits both wnt1/β-catenin signaling and IGF1/Akt axis in the myoepithelial tumor cells which results in the suppression of epithelial-mesenchymal transition (EMT) in these tumors. Since wnt1 tumors resemble basal-like breast cancer with a poor clinical prognosis in which EMT is one of the most important way for tumor cells to survive against standard treatment and to go to metastasis, we propose that (1) the stromal gene expression signature of Rarb ablation in wnt1 tumors could have some clinical value in predicting the breast cancer outcome; and (2) Rarb antagonist might be a potential therapeutic strategy in EMT-driven aggressive cancers such as basal-like breast cancer.
ORGANISM(S): Mus musculus
PROVIDER: GSE56391 | GEO | 2014/10/23
SECONDARY ACCESSION(S): PRJNA243292
REPOSITORIES: GEO
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