Transformation of hemopoietic cells by raf and myc oncogenes: a new perspective on lineage commitment.

The effects of the raf and myc oncogenes on murine hemopoietic cells are quite distinct. The raf-1 gene, which encodes a serine/threonine kinase that is involved in signal transduction, preferentially transforms erythroid cells, whereas myc, which encodes a DNA-binding protein, induces lymphoid and myeloid neoplasms. Together, raf and myc form a potent leukemogenic combination and they act synergistically to transform cells from all hemopoietic lineages. Strikingly, the expression of exogenous raf and myc in lymphoid and erythroid cells enables these cells to change lineages and become myeloid cells, an observation that raises interesting questions concerning commitment to specific lineages.