Human lactoferrin inhibits growth of solid tumors and development of experimental metastases in mice.
The antitumor effects of the multifunctional iron-binding glycoprotein, lactoferrin (Lf), were investigated. Lf inhibited growth in mice of transplantable solid tumors induced by v-ras transformed fibroblasts and a methylcholanthrene-induced fibrosarcoma. Lf also substantially reduced lung colonization (experimental metastasis) by B16-F10 melanoma cells in syngeneic mice. Iron-saturated and apo-Lf exhibited comparable levels of tumor inhibition and antimetastatic activity. Transferrin, a related iron-binding protein, had no effect on lung colonization. In the B16-F10 system, elimination of natural killer cell activity by pretreatment of mice with anti-asialo GM1 antibody abrogated the effects of Lf, whereas inhibition of macrophage function with silica did not. The results demonstrate a novel activity for Lf and suggest a potentially important role for this molecule in the primary defense against tumorigenesis.
Bezault
J
J
New York University, Department of Biology, New York 10003.
Bhimani
R
R
Wiprovnick
J
J
Furmanski
P
P
D016475:3T3 Cells / Q000473:pathology*; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D005260:Female; D005350:Fibroma / Q000139:chemically induced / Q000473:pathology*; D006801:Humans; D007781:Lactoferrin / Q000494:pharmacology*; D008748:Methylcholanthrene; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis; D014407:Tumor Cells, Cultured
D008748:Methylcholanthrene; D007781:Lactoferrin