AffiliationUniv Arizona, Ctr Canc
KeywordsReceptor tyrosine kinase
Hematopoietic stem cells
Hematopoietic progenitor cells
MetadataShow full item record
PublisherBIOMED CENTRAL LTD
CitationPim1 kinase regulates c-Kit gene translation 2016, 5 (1) Experimental Hematology & Oncology
Rights© The Author(s) 2016. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License.
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AbstractBackground: Receptor tyrosine kinase, c-Kit (CD117) plays a pivotal role in the maintenance and expansion of hematopoietic stem/progenitor cells (HSPCs). Additionally, over-expression and/or mutational activation of c-Kit have been implicated in numerous malignant diseases including acute myeloid leukemia. However, the translational regulation of c-Kit expression remains largely unknown. Methods and results: We demonstrated that loss of Pim1 led to specific down-regulation of c-Kit expression in HSPCs of Pim1(-/-)mice and Pim1(-/-)2(-/-)3(-/-) triple knockout (TKO) mice, and resulted in attenuated ERK and STAT3 signaling in response to stimulation with stem cell factor. Transduction of c-Kit restored the defects in colony forming capacity seen in HSPCs from Pim1 (-/-) and TKO mice. Pharmacologic inhibition and genetic modification studies using human megakaryoblastic leukemia cells confirmed the regulation of c-Kit expression by Pim1 kinase: i.e., Pim1-specific shRNA knockdown down-regulated the expression of c-Kit whereas overexpression of Pim1 up-regulated the expression of c-Kit. Mechanistically, inhibition or knockout of Pim1 kinase did not affect the transcription of c-Kit gene. Pim1 kinase enhanced c-Kit S-35 methionine labeling and increased the incorporation of c-Kit mRNAs into the polysomes and monosomes, demonstrating that Pim1 kinase regulates c-Kit expression at the translational level. Conclusions: Our study provides the first evidence that Pim1 regulates c-Kit gene translation and has important implications in hematopoietic stem cell transplantation and cancer treatment.
NoteOpen Access Journal.
VersionFinal published version
SponsorsMUSC Hollings Cancer Center Startup Fund, Hollings Cancer Center ACS IRG; ASCO Conquer Cancer Foundation Career Development Award; NHLBI [K08HL103780]; NCI [P30CA138313-01S3, R01CA197792, R01CA173200, R01CA172495]; DOD [W81XWH-15-1-0507]