Description
The pim-1 oncogene encodes a serine/threonine kinase (Pim-1) involved in the transduction of cytokine triggered mitogenic signals. The pim-1 oncogene was originally identified as a genetic locus frequently activated by the proviral insertion of Moloney murine leukemia virus into mouse T cell lymphomas. The pim-1 oncogene has also been implicated in human hematopoietic malignancies, with its overexpression frequently detected in human hematopoietic cell lines as well as in fresh tumor cells from patients with leukemia. During embryonal development, the pim-1 gene is expressed mainly in developing fetal hematopoietic tissues. The pim-1 gene product (Pim-1), identified as a serine/threonine kinase, has been thought to play a critical role in the transduction of mitogenic signals from cytokines since Pim-1 expression is rapidly induced after cytokine stimulation, and the proliferative response to cytokines is impaired in cells from pim-1-deficient mice. When overexpressed, pim genes can efficiently cooperate with myc or bcl-2 oncogenes in lymphomagenesis. Pim-1 has been reported to protect thymocytes against glucocorticoid- induced apoptosis and to promote cell proliferation or survival in several IL-3- or IL-6-dependent hematopoietic cell lines