Lif: A molecule with divergent actions on myeloid leukaemic cells and embryonic stem cells

Abstract

We have previously characterized, purified and cloned a novel murine and human regulator [leukaemia inhibitory factor, LIF] which induces the differentiation of certain murine and human myeloid leukaemic cells. Recently we have shown that there are specific LIF receptors on murine embryonic stem [ES] and embryonal carcinoma [EC] cells and that purified recombinant LIF can substitute for feeder cells and crude sources of differentiation inhibiting activity [DIA] [such as BRL-cell-conditioned medium] in the maintenance of ES cells in a pluripotential state in vitro. Furthermore, ES cells maintained in culture in recombinant LIF for a prolonged period can give rise to germline chimaeric mice. T..