THE ANTI-TUMORAL ACTIVITY OF HUMAN GLYCOPROTEIN HGP.92 - A STUDY WITHTHE MOUSE LEWIS-LUNG-TUMOR CELL

The ability of a purified human glycoprotein (HGP.92) to exert anti-tu mor activity was investigated in a mouse model using long-term readout assays. In vitro, in the presence of inflammatory mouse macrophages i ncubated with HGP.92, the growth of the mouse Lewis-lung-tumor cells ( 3LL) was decreased. This effect was concentration-dependent and requir ed direct contact between tumor targets and HCP.92-treated macrophages . In addition, if the macrophage monolayer was depleted of HGP.92 befo re addition of the target cells, no more cytostatic effect was observe d. This anti-tumor activity of HGP.92-treated mouse macrophage was par tially abrogated by addition of catalase in the culture medium, but no t by superoxide dismutase or scavengers of the hydroxyl radical and si nglet oxygen. Moreover, this tumor-cell growth reduction was not depen dent on nitric oxide. In vivo, multiple i.v. injections of HGP.92 (5 t imes, 3 days apart) during the first week and a half exerted significa nt anti-tumor activity, as assessed by the reduction of both the numbe r and the size of the lung nodules 3 weeks after i.v. inoculation of 3 LL cells. (C) 1997 Wiley-Liss, Inc.