Inhibition of proliferation of Ehrlich ascites carcinoma cells in vitro and in vivo by halogeno analogues of long chain acyl- and alkylglycerols.

A series of halogeno (chloro or fluoro) analogues of phospholipid precursors has been checked for their cytostatic activity both in vitro and in vivo. The compounds included monoacyl-, diacyl-, monoalkyldeoxyhalogenoglycerols and other acylhalogenoalkanols. Analogues of monoacylglycerols or monoalkylglycerols were found to have a strong inhibitory activity on the proliferation of Ehrlich ascites carcinoma cells in suspension culture. The compounds were also effective in vivo. Tolerable doses (e.g. 1/10 of the LD50) given i.p. only once on the first day after transplantation of EAC cells reduced the cell number on day 7 by 99% or increased the survival time about 4-fold. The in vivo efficacy or the ether derivatives was higher than that of the corresponding esters. However, most of the compounds so far investigated had no effect on the survival time or cell number after s.c. application. Moreover, there was no prolongation of the survival time of leukemia L1210 or L184 bearing mice. This shows that the systemic effects of most of the compounds are low and that they have to come into direct contact with tumour cells during application in order to be active. It is discussed whether theese compounds interfere more with the structure of the membrane than with membrane biosynthesis. However, at least in comparison to Tween 80 (which is of poorer cytostatic activity) they show only very low lytic effects on red blood cells.