Autocrine stimulation via coexpression of hepatocyte growth factor (HGF) and its receptor (Met) has been reported in many human sarcomas, but few in carcinomas. In this report, we found that one gastric cancer cell line, SNU-484, among 11 gastric cell lines tested has an autocrine HGF- Met stimulation. RT-PCR, ELISA and scattering assay using MDCK cells revealed that SNU-484 cells secreted a significant amount of active HGF (about 1.25 +/- 0.41 ng/24 h/106 cells) into conditioned medium. Resultantly, Met in this cell line was constitutively phosphorylated. Neutralizing antibodies against HGF reduced the tyrosine phosphorylation of Met, resulting in the inhibition of cell proliferation and migration (P <0.005). To the best of our knowledge, this is the first report on autocrine HGF-Met signaling in a gastric cancer cell line. Our observations with SNU-484 cells suggest that HGF is involved in the development and/or progression of some gastric carcinoma through an autocrine mechanism.
Animals ; Antibodies, Neoplasm/immunology ; *Autocrine Communication ; *Cell Movement ; Cell Proliferation ; Culture Media, Conditioned/pharmacology ; Dogs ; Enzyme-Linked Immunosorbent Assay ; Hepatocyte Growth Factor/immunology/*pharmacology ; Neutralization Tests ; Phosphorylation ; Proto-Oncogene Protein c-met/genetics/*metabolism ; Research Support, Non-U.S. Gov't ; Reverse Transcriptase Polymerase Chain Reaction ; Stomach Neoplasms/*immunology/metabolism/pathology ; Tumor Cells, Cultured ; Tyrosine/metabolism

To observe the effects of hepatocyte growth factor (HGF) on graft-versus-host disease (GVHD) and Th1/Th2 related cytokines in mice with acute lymphoblastic leukemia (ALL) after allogenic bone marrow transplantation (allo-BMT), BALB/c mice were conditioned by total body irradiation with 11 Gy and then were transplanted with allogeneic bone marrow after establishing ALL model. BALB/c mice were divided into groups A and B. The mice of group A were injected subcutaneously with HGF from day 0 to 7 after allo-BMT, and the mice of group B were injected subcutaneously with PBS from day 0 to 7 after allo-BMT. The symptoms of GVHD and the GVHD pathological changes of liver and small intestine and skin were observed. The serum levels of both IFN-gamma and IL-4 were determined by ELISA. The results showed that the score of GVHD in group A was lower than that in group B (P < 0.05). The levels of IFN-gamma in both groups A and B were all higher than that in normal group (P < 0.05 and P < 0.001, respectively), However, the level of IFN-gamma in group A was lower than that in group B (P < 0.01). The levels of IL-4 in both group A and B were all lower than that in normal group (P < 0.05), but the level of IL-4 in group A was higher than that in group B (P < 0.05). It is concluded that HGF can alleviates the severity of GVHD, because of its balancing the Th1/Th2-related cytokines after allo-BMT.
Animals ; Bone Marrow Transplantation ; adverse effects ; methods ; Cytokines ; blood ; Enzyme-Linked Immunosorbent Assay ; Female ; Graft vs Host Disease ; immunology ; prevention & control ; Hepatocyte Growth Factor ; pharmacology ; Interferon-gamma ; blood ; Interleukin-4 ; blood ; Male ; Mice ; Mice, Inbred BALB C ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; blood ; immunology ; surgery ; Th1 Cells ; immunology ; Th2 Cells ; immunology ; Transplantation, Homologous

OBJECTIVETo investigate the effect of hepatocyte growth factor (HGF) on graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) after allogeneic bone marrow transplantation (allo-BMT) and related mechanism in acute lymphoblastic leukemia (ALL) mice.

METHODSTwenty nude mice were randomly divided into control (group A) and test (group B) groups for monitoring relapse, and 20 BALB/c mice into control (group C) and test (group D) groups for GVHD. HGF as injected from day 0 to day 7 after BMT for groups B and D, while PBS for A and C. CD4(+) and CD8(+) T cell were evaluated by flow cytometry. The survival of mice after BMT was recorded. The level of tumor necrosis factor-alpha (TNF-alpha) was evaluated by ELISA.

RESULTSThe median past-BMT survival were 7.00 +/- 1.58, 9.00 +/- 1.58, 11.00 +/- 3.95 and 24.00 +/- 13.44 days for groups A, B, C, D, respectively, being prolonged in group D. HGF could decrease the quantity of CD4(+) T cells [group D (10.39 +/- 1.15)% vs group C (13.50 +/- 1.80)%, P < 0.01] and increase CD8(+) T cell [group D (12.25 +/- 2.85)% vs group C (6.12 +/- 1.99)%, P < 0.01], decrease the level of TNF-alpha in transplanted ALL mice [group D (112.10 +/- 18.99) pg/ml vs group C (143.90 +/- 25.35) pg/ml, P < 0.01] and reduce the degree of GVHD.

CONCLUSIONHGF could alleviate post-allo-BMT GVHD but retain GVL effect.

Animals ; Bone Marrow Transplantation ; Disease Models, Animal ; Female ; Graft vs Host Disease ; prevention & control ; Graft vs Leukemia Effect ; drug effects ; Hepatocyte Growth Factor ; pharmacology ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; immunology ; surgery ; Random Allocation ; Transplantation, Homologous