Gética 2020

38 VI FORO DE Inmunología Traslacional e INMUNOTERAPIA DEL CÁNCER H ormone receptor (HR) + breast cancer (BC) caus- esmost BC-related deaths, calling for the devel- opment of improved therapeutic approaches. Despite expectations, immune checkpoint blockers (ICBs) are poorly active in patients with HR + BC, in part reflecting the lack of preclinical models that re- capitulate disease progression in immunocompetent hosts. We demonstrate that mammary tumors driv- en by medroxyprogesterone acetate (M) and 7,12-di- methylbenz[a]anthracene (D) recapitulate several key features of human luminal B HR + HER2 - BC, in- cluding limited immune infiltration and poor sensitiv- ity to ICBs. M/D-driven oncogenesis is accelerated by immune defects, demonstrating that M/D-driven tu- mors are under immunosurveillance. Safe nutritional measures including nicotinamide (NAM) supplemen- tation efficiently delay M/D-driven oncogenesis by reactivating immunosurveillance. NAM also medi- Lorenzo Galluzzi Weill Cornell Medical College. Nueva York, Estados Unidos Cáncer de mama HR + . Efectos profilácticos y terapéuticos de la nicotinamida ates immunotherapeutic effects against established M/D-driven and transplantable BC, largely reflecting increased type I interferon secretion by malignant cells and direct immunostimulation of immune ef- fector cells. Our findings identify NAM as a potential strategy for the prevention and treatment of HR + BC.