Augmented anti-tumour effect of lipopolysaccharide with G-CSF without enhancing body weight loss in mice bearing MH134 hepatoma.

BACKGROUND: Although lipopolysaccharide (LPS) is reported effective for cancer, developmental application as anti-tumour therapeutic agents have been prevented due to its severe toxicity. Since antitumour action of LPS was suggested to be partly related to the function of neutrophil, we investigated the effects of granulocyte colony stimulating factor (G-CSF), a cytokine enhancing neutrophil function, on antitumour activity of bacterial LPS against a murine syngeneic hepatoma MH134.

METHODS: Effect of G-CSF (30 μg/kg i.v. pretreatment, 4 days) and LPS (20μg/mouse) on tumor growth and survival days of mice bearing MH134 hepatoma were monitored.

RESULTS: 4 day treatment of G-CSF 30 μg/kg increased the neutrophil level with statistical significance. On the MH134 hepatoma bearing mice, LPS significantly inhibited the tumour growth. Although G-CSF pretreatment alone did not inhibit the growth, once combined with LPS, significant inhibition was observed compared with LPS group. Tumour regression was demonstrated in combination group (6/12 mice), and survival of the mice in the combination group exceeded those of the LPS monotherapy group without enhancing the body weight loss.

CONCLUSIONS: Combination of G-CSF and LPS prominently inhibit the tumour growth and elongated the survival days without enhancing a toxic response to LPS treatment.