Targeting the Endothelin-A-Receptor Inhibits Breast Carcinoma Growth in Vivo

Previously we found Endothelin-A-receptor (ETAR) to be overexpressed in breast carcinomas and demonstrated its potential significance as a target for breast cancer treatment. In the present study, we investigated the antitumoral effects of the selective ETAR antagonist atrasentan (ABT-627; 10mg/kg/d i.p.) in a MCF-7 xenografted nude mouse breast cancer model (animals: n=40). Treatment was initiated 10 days after tumor cell implantation and atrasentan effects were compared to those of paclitaxel (20mg/kg i.p. q4d) either alone or in combination with atrasentan. Atrasentan showed significant tumor growth inhibitio…