Dl-alpha-tocopherol, a potent inhibitor of phorbol ester induced shape change of erythro- and megakaryoblastic leukemia cells

Synthetic vitamin E, dl-α-tocopherol, added to a human erythroleukemia HEL and a megakaryoblastic leukemia, Meg-01, cell culture produced potent dose-dependent inhibition of phorbol ester-induced adhesion and of the morphologic changes accompanying it. The inhibition was reversible by withdrawal of supplemental vitamin E from the medium. dl-α-Tocopherol also inhibited protein kinase C activity both at baseline and after phorbol ester...