A selective c-met inhibitor blocks an autocrine hepatocyte growth factor growth loop in ANBL-6 cells and prevents migration and adhesion of myeloma cells.
OBJECTIVE
We wanted to examine the role of the hepatocyte growth factor (HGF) receptor c-Met in multiple myeloma by applying a novel selective small molecule tyrosine kinase inhibitor, PHA-665752, directed against the receptor.


METHODS
Four biological sequels of HGF related to multiple myeloma were studied: (1) proliferation of myeloma cells, (2) secretion of interleukin-11 from osteogenic cells, (3) migration of myeloma cells, and (4) adhesion of myeloma cells to fibronectin. We also examined effects of the c-Met inhibitor on intracellular signaling pathways in myeloma cells.


RESULTS
PHA-665752 effectively blocked the biological responses to HGF in all assays, with 50% inhibition at 5 to 15 nmol/L concentration and complete inhibition at around 100 nmol/L. PHA-665752 inhibited phosphorylation of several tyrosine residues in c-Met (Tyr(1003), Tyr(1230/1234/1235), and Tyr(1349)), blocked HGF-mediated activation of Akt and p44/42 mitogen-activated protein kinase, and prevented the adaptor molecule Gab1 from complexing with c-Met. In the HGF-producing myeloma cell line ANBL-6, PHA-665752 revealed an autocrine HGF-c-Met-mediated growth loop. The inhibitor also blocked proliferation of purified primary myeloma cells, suggesting that autocrine HGF-c-Met-driven growth loops are important for progression of multiple myeloma.


CONCLUSIONS
Collectively, these findings support the role of c-Met and HGF in the proliferation, migration, and adhesion of myeloma cells and identify c-Met kinase as a therapeutic target for treatment of patients with multiple myeloma.
Hov
Håkon
H
Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Holt
Randi Utne
RU
Rø
Torstein Baade
TB
Fagerli
Unn-Merete
UM
Hjorth-Hansen
Henrik
H
Baykov
Vadim
V
Christensen
James G
JG
Waage
Anders
A
Sundan
Anders
A
Børset
Magne
M
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D017228:Hepatocyte Growth Factor / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D015151:Immunoblotting; D007211:Indoles / Q000494:pharmacology*; D017370:Interleukin-11 / Q000378:metabolism; D009101:Multiple Myeloma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D019859:Proto-Oncogene Proteins c-met / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013450:Sulfones / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism
C480541:5-((2,6-dichlorobenzyl)sulfonyl)-3-((3,5-dimethyl-4-((2-(pyrrolidin-1-ylmethyl)pyrrolidin-1-yl)carbonyl)-1H-pyrrol-2-yl)methylene)-1,3-dihydro-2H-indol-2-one; D007211:Indoles; D017370:Interleukin-11; D013450:Sulfones; D016212:Transforming Growth Factor beta; D014443:Tyrosine; D017228:Hepatocyte Growth Factor; D019859:Proto-Oncogene Proteins c-met