INHIBITION OF TUMOR ANGIOGENESIS BY ROXITHROMYCIN, A 14-MEMBERED RINGMACROLIDE ANTIBIOTIC

We examined the effects of roxithromycin, a 14-membered ring macrolide antibiotic, on tumor angiogenesis using a mouse dorsal air sac model. The inhibitory effect of roxithromycin was dose-dependent and 100 mg/ kg of roxithromycin administered intraperitoneally twice a day reduced the dense capillary network area to about 20% of the control. However , at concentrations of up to 50 mu M, roxithromycin had no effect on l ung cancer cells and human vascular endothelial cell growth and lung c ancer cell production of the angiogenesis-inducing factors interleukin -8 and vascular endothelial growth factor. Roxithromycin at concentrat ions greater than 20 mu M inhibited endothelial cell migration and tub e formation. (C) 1998 Elsevier Science Ireland Ltd. All rights reserve d.