Macrocyclic lathyrane diterpenes as antitumor promoters.

Human cytomegalovirus (CMV) preferentially infects tumor tissues and the accumulated CMV immediate-early (IE) antigen may lead to tumor promotion and progression. The development of strategies to inhibit human CMV IE antigen expression and/or function is an important goal to prevent and treat certain forms of cancers associated with human CMV. The aim of this study was to search for antitumor promoters from plant sources. The effect of six macrocyclic lathyrane-type diterpenoids, latilagascenes A-E (1-5) and jolkinol B (6), isolated from the methanol extract of Euphorbia lagascae, on the expression of IE antigen in lung cancer cells (A549) infected by CMV was studied. All the compounds, except latilagascene D (4), decreased IE antigen expression of CMV.