INVESTIGADORES
GIULIANELLI Sebastian Jesus
congresos y reuniones científicas
Título:
The ratio of progesterone receptor isoforms predicts progestin and antiprogestin response: Interaction of PR with AIB1 or SMRT
Autor/es:
RIGGIO, MARINA; GIULIANELLI, SEBASTIÁN; WARGON, VICTORIA; NOVARO, VIRGINIA; LANARI, CLAUDIA
Lugar:
Washington
Reunión:
Congreso; AACR Annual Meeting 2013; 2013
Institución organizadora:
AACR
Resumen:
We have previously demonstrated in a mouse model of breast cancer that mammary carcinomas which are responsive to the antiprogestin mifepristone (MFP) express higher levels of isoform A of progesterone receptor (PRA) than isoform B (PRB). PRB is predominant in tumors with constitutive or acquired resistance to MFP, indicating that the PR isoform ratio might predict antiprogestin responsiveness. The aim of this study was to evaluate the effect of MFP and of medroxyprogesterone acetate (MPA) on the growth of human breast cancer xenografts showing different ratios of PR isoforms. We chose IBH-6 cells since they express hormone receptors and they give rise to tumor xenografts without the need of exogenous hormone supply. IBH-6 tumors express higher levels of PRB than PRA and they are not inhibited by antiprogestin treatment. We stably transfected these cells with PRA, PRB or empty vector and sc inoculated 106 transfected cells into the right flank of female nude (nu/nu) mice. When tumors reached a size of 9 mm2, animals were treated sc with MFP (10 mg/kg/day), MPA (20 mg depot) or vehicle. Interestingly, only tumors showing higher levels of PRA than PRB were inhibited with MFP treatment (p