Charcterization of a Newly Established Megakaryo/Erythroid Leukemia Cell Line, JAS-R.

A few leukemic cell lines which express megakaryo/erythroid markers are available. We recently established a new cell line, designated JAS-R, from a 64-year-old patient with acute megakaryocytic leukemia (AML M7). Immunophenotyping showed that JAS-R cells were positive for CD4, CD7, CD13, CD33, CD41, CD61 and glycophorin A. Chromosome analysis was composite karyotype, but no major translocation abnormalities were observed. Electron-microscope examination disclosed that JAS-R had bleb like surface margin and a-granules in cytoplasm. Major four proteins which exist in a-granule were expressed high levels in JAS-R by RT-PCR. To further characterize JAS-R from four other megakaryo/erythroid cell lines (MEG-01, CMK, K562 and KU812), the comparison of gene expression profiling was studied by using oligo-DNA array. JAS-R was categorized as most different cell line among them. Of note, JAS-R secreted erythropoietin and expressed erythropoietin-receptor. But erythropoietin-neutralizing antibody failed to inhibit the growth of JAS-R cells. JAS-R may be useful for the further understanding of megakaryo and erythroid regulation and for the study of megakaryo/erythroid leukemogenesis.