Distinct molecular pathways mediate Mycn and Myc-regulated miR-17-92 microRNA action in Feingold syndrome mouse models.

ABSTRACT: Feingold syndrome is a skeletal dysplasia caused by loss-of-function mutations of either MYCN (type 1) or MIR17HG that encodes miR-17-92 microRNAs (type 2). Since miR-17-92 expression is transcriptionally regulated by MYC transcription factors, it has been postulated that Feingold syndrome type 1 and 2 may be caused by a common molecular mechanism. Here we show that Mir17-92 deficiency upregulates TGF-? signaling, whereas Mycn-deficiency downregulates PI3K signaling in limb mesenchymal cells. Genetic or pharmacological inhibition of TGF-? signaling efficiently rescues the skeletal defects caused by Mir17-92 deficiency, suggesting that upregulation of TGF-? signaling is responsible for the skeletal defect of Feingold syndrome type 2. By contrast, the skeletal phenotype of Mycn-deficiency is partially rescued by Pten heterozygosity, but not by TGF-? inhibition. These results strongly suggest that despite the phenotypical similarity, distinct molecular mechanisms underlie the pathoetiology for Feingold syndrome type 1 and 2.

SUBMITTER: Mirzamohammadi F 

PROVIDER: S-EPMC5893605 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature