Cloning and mapping of the MEIS1 gene, the human homolog of a murine leukemogenic gene.

he mammalian homeobox genes encode a family of transcription factors that are important in a wide range of cellular processes, including hematopoiesis. Aberrant expression of some homeobox genes is known to be oncogenic. We report the cloning and initial characterization of a human homeobox gene, MEIS1, identified in a survey of homeobox genes expressed in the human fetal liver. The complete cDNA sequence shows that MEIS1 is likely to be the human homolog of Meis1, a mouse gene that is known to be activated in myeloid leukemia by retroviral insertion. We found that the MEIS1 gene is expressed at low levels in normal immunohematopoietic tissues, including the fetal liver. However, consistent with its possible role in myeloid leukemogenesis, MEIS1 was expressed in a subset of myeloid leukemia cell lines, with the highest expression seen in those with a megakaryocytic-erythroid phenotype. The gene is also expressed at high levels in the cerebellum. The gene is located on human chromosome region 2p13-p14 and contains the previously identified anonymous markers D2S134 and NIB1519. Whether this gene, which is leukemogenic in mice, also plays a leukemogenic role in humans will require further study.