Haemin promotes rapid neurite outgrowth in cultured mouse neuroblastoma cells

Abstract

MOUSE neuroblastoma cells grown in suspension culture are round and anaplastic, but when grown in culture attached to a surface and in the presence of various inducing agents such as dibutyryl cyclic AMP¹, bromodeoxyuridine², prostaglandin E₁ (ref. 3), cytosine arabinoside⁴, papaverine⁵, dimethyl sulphoxide (DMSO)^6,7, hexamethylene bisacetamide^6,7, or serum-free medium^8,9, the cells will extend neurites and assume a morphology resembling that of the mature neurone. The mechanism of neurite outgowth is unknown. Neurite outgrowth develops slowly in the presence of the defined agonists, usually requiring one to several days to attain the optimum outgrowth. Thus, the possible importance of cell-cycle associated events and cell division can complicate the interpretation of experimental results. And, with serum deprivation, nonspecific alterations may result from the removal of numerous factors in the complex mixture comprising serum. Therefore, the availability of a rapidly acting agonist effective in the presence of the normal complement of serum would be a useful tool. We report here that haemin can rapidly and reversibly induce neurite outgrowth in cultured mouse neuroblastoma cells and suggest that haemin may have a wider role in cells than previously thought.