p53 status of newly established acute myeloid leukaemia cell lines

We analysed the status of the p53 gene and protein in eight newly establish ed acute myeloid leukaemia (AML) cell lines representing blast cells of eit her de novo leukaemia patients in first remission or patients with relapsed and chemotherapy-resistant disease causing their death. There were no muta tions in the p53 gene in any of the cell lines as analysed by single-strand conformation polymorphism of amplified exons 5-8. However, the p53 protein was clearly and consistently expressed in all of these cell lines, as show n by immunohistochemistry, Western blotting and flow cytometry. The consist ently expressed p53 protein was located in both the nucleus and the cytopla sm of all the cell lines and, as shown by flow cytometry, it was mostly in a conformation typical of the mutated protein. These AML cell lines offer a tool for studying the production and function of the p53 protein and its p ossible role in cell cycle regulation and chemoresistance as well as in the regulation of apoptosis in AML.