HEPATOCYTE GROWTH-FACTOR AND ITS RECEPTOR C-MET IN MULTIPLE-MYELOMA

We have examined whether the hepatocyte growth factor (HGF)/c-met rece ptor-ligand pair is expressed in freshly isolated and highly purified myeloma cells and whether HGF can be found in the sera of myeloma pati ents. Myeloma cells were purified with an immunomagnetic method using the syndecan 1-specific antibody B-B4, HGF and c-met mRNA in these cel ls were examined by reverse transcriptase-polymerase chain reaction (R T-PCR). HGF and c-met proteins were defected by enzyme-linked immunoso rbent assay (ELISA) tend Western blot, respectively. Serum from 13 mye loma patients was obtained at diagnosis and the levels of HGF were det ermined by ELISA, HGF and c-met mRNA were expressed in all examined sa mples (n = 7), HGF was detected in the supernatants of 17 of 20 primar y cultures of myeloma cells, whereas bone marrow mononuclear cells fro m normal controls did not produce detectable amounts of HGF (n = 3). T he mean HGF level in serum of myeloma patients at diagnosis was more t han fourfold higher than the mean level in normal controls. Possible i mplications of HGF/c-met expression for the pathophysiology of multipl e myeloma are discussed. (C) 1996 by The American Society of Hematolog y.