Effect of rosiglitazone on N-nitroso-N-methylurea-induced mammary tumors in rat.

NUÑEZ MARIEL; MARTIN GABRIELA; COCCA CLAUDIA; MOHAMAD NORA; GUTIERREZ ALICIA; CRICCO GRACIELA; MEDINA VANINA; RIVERA ELENA; CROCI MAXIMO; CRESCENTI ERNESTO; BERGOC ROSA

ANTICANCER RESEARCH

J.G. Delinassios, Anticancer Research

Lugar: Grecia; Año: 2006 vol. 26 p. 2113 - 2122

0250-7005

The objective of this study was to evaluate the in vivo antitumor action of rosiglitazone (Rosi) alone or in combination with tamoxifen (Tam) on experimental mammary tumors induced by N-nitroso-N-methylurea (NMU) in Sprague-Dawley rats. Animals bearing mammary tumors were treated with 0.06 mg/kg/day or 0.12 mg/kg/day of Rosi orally, 1 mg/kg/day of Tam s.c., or with the combined treatment (Rosi+Tam). After 25 days of treatment, the following responses were observed: 45% of tumors were responsive to 0.06 mg/kg/day of Rosi treatment, while 55% of tumors under Tam treatment responded. The results of the combined Rosi+Tam treatment indicated that 75% of tumors were responsive. Similar results were obtained with 0.12 mg/kg/day of Rosi. Apoptosis, necrosis and glandular hypersecretion were observed in Rosi-treated tumors. In all cases, the combined Rosi+Tam treatment potentiated the antitumor effect of Tam alone. No side-effects were observed after treatment at any assayed dose.