The oncogenic properties of EWS/WT1 of desmoplastic small round cell tumors are unmasked by loss of p53 in murine embryonic fibroblasts.
Journal Article (Journal Article)
BACKGROUND: Desmoplastic small round cell tumor (DSRCT) is characterized by the presence of a fusion protein EWS/WT1, arising from the t (11;22) (p13;q12) translocation. Here we examine the oncogenic properties of two splice variants of EWS/WT1, EWS/WT1-KTS and EWS/WT1 + KTS. METHODS: We over-expressed both EWS/WT1 variants in murine embryonic fibroblasts (MEFs) of wild-type, p53+/- and p53-/- backgrounds and measured effects on cell-proliferation, anchorage-independent growth, clonogenicity after serum withdrawal, and sensitivity to cytotoxic drugs and gamma irradiation in comparison to control cells. We examined gene expression profiles in cells expressing EWS/WT1. Finally we validated our key findings in a small series of DSRCT. RESULTS: Neither isoform of EWS/WT1 was sufficient to transform wild-type MEFs however the oncogenic potential of both was unmasked by p53 loss. Expression of EWS/WT1 in MEFs lacking at least one allele of p53 enhanced cell-proliferation, clonogenic survival and anchorage-independent growth. EWS/WT1 expression in wild-type MEFs conferred resistance to cell-cycle arrest after irradiation and daunorubicin induced apoptosis. We show DSRCT commonly have nuclear localization of p53, and copy-number amplification of MDM2/MDMX. Expression of either isoform of EWS/WT1 induced characteristic mRNA expression profiles. Gene-set enrichment analysis demonstrated enrichment of WNT pathway signatures in MEFs expressing EWS/WT1 + KTS. Wnt-activation was validated in cell lines with over-expression of EWS/WT1 and in DSRCT. CONCLUSION: In conclusion, we show both isoforms of EWS/WT1 have oncogenic potential in MEFs with loss of p53. In addition we provide the first link between EWS/WT1 and Wnt-pathway signaling. These data provide novel insights into the function of the EWS/WT1 fusion protein which characterize DSRCT.
Full Text
Duke Authors
Cited Authors
- Bandopadhayay, P; Jabbour, AM; Riffkin, C; Salmanidis, M; Gordon, L; Popovski, D; Rigby, L; Ashley, DM; Watkins, DN; Thomas, DM; Algar, E; Ekert, PG
Published Date
- December 9, 2013
Published In
Volume / Issue
- 13 /
Start / End Page
- 585 -
PubMed ID
- 24321497
Pubmed Central ID
- PMC4029184
Electronic International Standard Serial Number (EISSN)
- 1471-2407
Digital Object Identifier (DOI)
- 10.1186/1471-2407-13-585
Language
- eng
Conference Location
- England