Dual Pten/p53 suppression enhances Notch signaling and sarcoma progression

ABSTRACT: Soft tissue sarcomas (STS) are a heterogeneous group of tumors associated with poor clinical outcome. While a subset of STS are characterized by simple karyotypes and recurrent chromosomal translocations, the mechanisms driving cytogenetically complex sarcomas are largely unknown. Clinical evidence led us to partially inactivate Pten and p53 in the smooth muscle lineage of mice, which developed high-grade undifferentiated pleomorphic sarcomas (HGUPS), leiomyosarcomas (LMS) and carcinosarcomas (CS) that widely recapitulate the human disease, including the aberrant karyotype and metastatic behavior. Pten was found haploinsufficient whereas the wild-type allele of p53 invariably gained point mutations. Gene expression profile showed upregulated Notch signaling in PtenM-bM-^HM-^F/+p53M-bM-^HM-^F/+ tumors compared to Pten+/+p53M-bM-^HM-^F/+. Consistently, Pten silencing exacerbated the clonogenic and invasive potential of p53-deficient bone marrow-derived mouse mesenchymal stem cells and tumor cells, while activating the Notch pathway. Moreover, the increased oncogenic behavior of PtenM-bM-^HM-^F/+p53M-bM-^HM-^F/+ and shPten-transduced Pten+/+p53M-bM-^HM-^F/+ tumor cells was counteracted by treatment with a gamma secretase inhibitor (GSI), suggesting that the aggressiveness of those tumors can be attributed, at least in part, to enhanced Notch signaling. This study demonstrates a cooperative role for Pten and p53 suppression in complex karyotype sarcomas while establishing Notch as an important functional player in the crosstalk of these pathways during tumor progression. Our results highlight the importance of molecularly subclassifying high-grade sarcoma patients for targeted treatments. Compare PtenM-bM-^HM-^F/+p53M-bM-^HM-^F/+ to Pten+/+p53M-bM-^HM-^F/+ high-grade undifferentiated pleomorphic sarcomas (HGUPS) 4 PtenM-bM-^HM-^F/+p53M-bM-^HM-^F/+ were compared to 5 Pten+/+p53M-bM-^HM-^F/+ Keywords: Differential gene expression.

ORGANISM(S): Mus musculus

SUBMITTER: Jiri Zavadil 

PROVIDER: E-GEOD-42103 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress