The differentiation stage of p53- and Rb-deficient bone marrow mesenchymal stem cells imposes the phenotype of in vivo sarcoma development (part II)

ABSTRACT: We have previously reported that the deficiency of p53 alone or in combination with Rb (Rb-/- p53-/-) in adipose-derived MSCs (ASCs) promotes leiomyosarcoma-like tumors in vivo. Here, we hypothesized that the source of MSCs and/or the cell differentiation stage could determine the phenotype of sarcoma development. To investigate whether there is a link between the source of MSCs and sarcoma phenotype, we generated p53-/- and Rb-/-p53-/- MSCs from bone marrow (BM-MSCs). Both genotypes of BM-MSCs initiated leiomyosarcoma formation similar to p53-/- and Rb-/-p53-/- ASCs. In addition, gene expression profiling revealed a link between p53- or Rb-p53-deficient BM-MSCs and ASCs and muscle-associated sarcomagenesis. These data suggest that the tissue source of MSC does not seem a crucial factor in the development of a particular sarcoma phenotype. To analyze whether the differentiation stage defines the sarcoma phenotype, BM-MSCs and ASCs were induced to differentiate towards the osteogenic lineage, and both p53 and Rb were excised using Cre-expressing adenovectors at different stages along osteogenic differentiation. Regardless of the level of osteogenic commitment, the inactivation of Rb and p53 in BM-MSC-derived, but not in ASC-derived, osteogenic progenitors gave rise to osteosarcoma-like tumors which could be serially transplanted. This indicates that the osteogenic differentiation stage of BM-MSCs imposes the phenotype of in vivo sarcoma development, and that BM-MSC-derived osteogenic progenitors rather than undifferentiated BM-MSCs, undifferentiated ASCs or ASC-derived osteogenic progenitors, represent the cell of origin for osteosarcoma development. To analyse whether the BM-MSC and Fat-MSC (ASC) differentiation stage may define the sarcoma phenotype, RbloxP/loxPp53loxP/loxP BM-MSCs and ASCs were induced to differentiate towards the osteogenic lineage and both Rb and p53 were excised with adenoviral vectors expressing the Cre-recombinase gene (Ad-CMV-Cre) at different stages (day 0 and 10) along osteogenic differentiation. NSG mice were inoculated subcutaneously with 5M-CM-^W10^6 mutant cells. Animals were killed when tumors reached 1 cm3 or 150 days after infusion. Some of the obtained tumors were mechanically disaggregated to establish ex vivo MSC-transformed cell lines. Gene expression analysis was performed using: WT BM-MSCs and ASCs, Rb-/-p53-/- BM-MSCs and ASCs previously differentiated to the osteogenic lineage for 10 days and a tumor cell line derived from p53-/-Rb-/- BM-MSC differentiated to the osteogenic lineage for 10 days.

ORGANISM(S): Mus musculus

SUBMITTER: Alberto Labarga 

PROVIDER: E-GEOD-43803 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress