Abstract
Tyrosine 177 and the Src homology 2 (SH2) domain play important roles in linking p185Bcr-Abl to downstream pathways critical for cell growth and survival. However, a mutant p185(Y177FR552L) (p185(YR)), in which tyrosine 177 and arginine 552 in the SH2 domain are mutated, is still capable of transforming hematopoietic cells in vitro. Transplant of these cells into syngeneic mice also leads to leukemogenesis, albeit with a phenotype distinct from that produced by wild-type p185Bcr-Abl (p185(wt))-transformed cells. Here we show that G-protein coupled receptor 34 (Gpr34) expression is markedly up-regulated in p185(YR)-transformed cells compared to those transformed by p185(wt). Knockdown of Gpr34 in p185(YR) cells is sufficient to suppress growth factor-independent proliferation and survival in vitro and attenuate leukemogenesis in vivo. The Erk and phosphatidylinositol 3-kinase/Akt pathways are activated in p185(YR) cells and the activation is dependent on Gpr34 expression. These studies identify Gpr34 as an alternative pathway that may mediate p185Bcr-Abl-induced transformation and leukemogenesis.
Keywords:
Bcr–Abl; Gpr34; IL-3; Leukemogenesis; PI3K/Akt pathway; apoptosis.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Adult
-
Animals
-
Apoptosis
-
Blotting, Western
-
Cell Cycle
-
Cell Proliferation
-
Cell Transformation, Neoplastic / genetics
-
Cell Transformation, Neoplastic / pathology*
-
Drug Resistance, Neoplasm
-
Extracellular Signal-Regulated MAP Kinases / genetics
-
Extracellular Signal-Regulated MAP Kinases / metabolism*
-
Female
-
Fusion Proteins, bcr-abl / genetics
-
Fusion Proteins, bcr-abl / metabolism*
-
Humans
-
Immunoenzyme Techniques
-
Leukemia / genetics
-
Leukemia / metabolism
-
Leukemia / pathology*
-
Male
-
Mice
-
Mice, Inbred BALB C
-
Middle Aged
-
Mutation / genetics
-
Phosphatidylinositol 3-Kinase / genetics
-
Phosphatidylinositol 3-Kinase / metabolism*
-
Phosphorylation
-
Proto-Oncogene Proteins c-akt / genetics
-
Proto-Oncogene Proteins c-akt / metabolism*
-
RNA, Messenger / genetics
-
Real-Time Polymerase Chain Reaction
-
Receptors, Lysophospholipid / genetics
-
Receptors, Lysophospholipid / metabolism*
-
Reverse Transcriptase Polymerase Chain Reaction
-
Signal Transduction
-
Tumor Cells, Cultured
Substances
-
G-protein-coupled receptor 34
-
RNA, Messenger
-
Receptors, Lysophospholipid
-
Phosphatidylinositol 3-Kinase
-
Fusion Proteins, bcr-abl
-
Proto-Oncogene Proteins c-akt
-
Extracellular Signal-Regulated MAP Kinases