Expression of multidrug resistance (mdr-1) and p53 genes in hematologic cell systems: Implications for biology and gene therapy

Expression of multidrug resistance and loss of mutation of the p53 gene are well-known characteristics of some cancers. Our understanding of the regulation and function of both genes is incomplete, yet both are expressed in normal hematopoiesis. Further study may help us understand both normal and leukemic drug resistance and hematopoiesis and may reveal opportunities to employ both genes in gene therapy. In this brief review, we describe hybrid techniques involving high-speed fluorescence-activated cell sorting and molecular analysis, which allow us to begin to isolate and study high-purity populations of cells with different hematologic lineages and degrees of differentiation. This ability not only wiill aid our understanding of hematopoiesis but also will enable us to purify populations of normal cells or cells transfected with genes such as that for multidrug resistance, which may be used in therapy.