Comparison of effects of CH50 on macrophage activation and its anti-tumor activity with those of lipopolysaccharides.
OBJECTIVE
To investigate the characterization of pharmacological action & of CH50, a recombinant polypeptide of human fibronectin, by comparing the effects of CH50 on macrophage activation and its anti-tumor activity with those of lipopolysaccharides (LPS).


METHODS
The production of nitric oxide (NO) as an index macrophage activation was determined by colorimetric assay. The interferon-gamma (IFN-gamma) transfection was performed with coprecipitation of calcium phosphate and DNA. The melanoma B16 cells were inoculated into abdominal cavity of mice and the number of tumor nodes was recorded.


RESULTS
At lower concentrations or when given alone in vitro, CH50 produced ten times less NO than LPS (P < 0.01). But at concentrations higher than 1 mg.L-1, CH50 activated the IFN-gamma-primed macrophages to produce NO to the same extent as LPS (P > 0.05). There was no synergism between CH50 and LPS. Both CH50 and LPS alone could reduce the number of tumor nodes in abdominal cavity of mice but CH50 had a stronger inhibitory effect on the growth of tumor in vivo as compared to LPS (P < 0.01). CH50/IFN-gamma had also a better inhibitory effect on tumor growth in vivo than LPS/IFN-gamma did.


CONCLUSIONS
In the presence of IFN-gamma, the ability of CH50 to activate macrophages is the same as that of LPS. But CH50 has better antitumorogenic effects in vivo against mouse melanoma as compared to LPS.
Zhang
G M
GM
Department of Medical Molecular Biology, Tongji Medical University, Wuhan 430030, China.
Feng
Z H
ZH
Li
D
D
Zhang
H
H
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D005353:Fibronectins / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects*; D017737:Macrophages, Peritoneal; D008297:Male; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D009368:Neoplasm Transplantation; D009569:Nitric Oxide / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D005353:Fibronectins; D008070:Lipopolysaccharides; D011993:Recombinant Fusion Proteins; D009569:Nitric Oxide