Recombinant human leukemia inhibitory factor is mitogenic for human bone-derived osteoblast-like cells

Recombinant human leukemia inhibitory factor (rhLIF) is mitogenic for human bone-derived osteoblast-like cells in vitro. [3H]-thymidine incorporation into DNA was stimulated dose-dependently in a prostaglandin E2-independent manner. rhLIF exerted no effect on either the basal or 1,25(OH)2D3-induced synthesis of osteocalcin or alkaline phosphatase (AP) activity. Following treatment with rhLIF, radiolabelled cell nuclei were co-localized with AP, indicating that the mitogenic effect of rhLIF occurs on cells of the osteogenic lineage. Local generation of LIF at the human bone surface may therefore serve as a potential autocrine/paracrine mitogen for progenitor cells of the osteoblastic lineage and so could correlate with the known bone forming properties of LIF.