Histamine receptor ligands as potential radiosensitizers of human breast cancer cells

D MARTINEL LAMAS; PG BRENZONI; MA NUñEZ; N MASSARI; ES RIVERA; VA MEDINA

Sochi

Congreso; European Histamine Research Society, XL Annual Meeting; 2011

European Histamine Research Society

We have previously demonstrated that histamine significantly protects healthy tissues against ionizing radiation damage in rodents. The aim of this work was to investigate whether histamine and its ligands could modulate in vitro radiosensitivity of two breast cancer cell lines, MDA-MB-231 [estrogen receptor (ER) -] and MCF-7 (ER+). For this purpose, we evaluated the response to gamma radiation using a Cesium 137 source (0 to 10 Gy). Cells were treated with histamine and/or specific ligands 24 h before irradiation and radiobiological parameters, including 2 Gy surviving fraction (SF2Gy), were obtained from the survival curves adjusted to the linear quadratic model [SF=e-(D+D2)]. Cell apoptosis was determined by the TUNEL assay and Annexin-V staining, while senescence was investigated through the activity of β-galactosidase after 2 Gy dose. Catalase activity and peroxide levels were measured spectrophotometrically and by flow cytometry, respectively. Result indicate that histamine increased radiosensitivity of MDA-MB-231 (SF2Gy 0.06±0.02 vs. 0.22±0.04, P