Loss of p53 exacerbates multiple myeloma phenotype by facilitating the reprogramming of hematopoietic stem/progenitor cells to malignant plasma cells by MAFB

Abstract

Multiple myeloma (MM) is a serious, mostly incurable human cancer of malignant plasma cells. Chromosomal translocations afecting MAFB are present in a signifcant percentage of multiple myeloma patients. Genetically engineered Sca1-MafB mice, in which MafB expression is limited to hematopoietic stem/progenitor cells (HS/p-Cs), display the phenotypic features of MM. Contrary to many other types of cancer, it is not yet known if the p53 gene plays any essential role in the pathogenesis of this disease. Here, we show, taking advantage of the Sca1-MafB MM mouse model, that loss of p53 does not rescue the multiple myeloma disease, but instead accelerates its development and exacerbates the MM phenotype. therefore, the efciency of the MafB-induced MM reprogramming of normal HS/p-Cs to terminally diferentiated malignant plasma cells is enhanced by p53 defciency, in analogy to what happens in reprogramming to pluripotency. these results raise caution about interfering with p53 function when treating multiple myeloma. © 2012 Landes Bioscience.