Role of H4 Receptor in Histamine-induced Inhibition of Human Breast Cancer Cell Proliferation

DIEGO MARTINEL LAMAS; PABLO BRENZONI; NOELIA MASSARI; MARIEL A NU&241EZZ; ROSA M BERGOC; ELENA S RIVERA; VANINA A MEDINA

Durham, Inglaterra

Congreso; European Histamine Research Society, XXXIX Annual Meeting; 2010

European Histamine Research Society

Histamine plays a critical role in growth regulation and differentiation during mammary gland development. Histamine H1, H2, H3 and H4 (H4R) receptors are expressed in different normal and malignant cell lines, and also in benign lesions and tumours derived from human mammary gland. We have reported that histamine regulates differentially signalling processes in normal and malignant breast cells. The aim of the present work was to investigate the biological responses triggered by histamine through the H4R in two breast cancer cell lines with different malignant characteristics. For that purpose in MDA-MB-231 [estrogen receptor (ER) a-] and MCF-7 (ERa+) breast cancer cell lines, we evaluated cell proliferation by the clonogenic assay, cell count and the incorporation of BrdU using H4R agonists [Clobenpropit (Clob) and VUF8430 (VUF)] and antagonists. Furthermore, cell senescence and differentiation were determined by â-galactosidase enzyme assay and lipid accumulation using Nile red staining and flow cytometry, respectively. Apoptosis was studied by Annexin-V staining and flow cytometry, and TUNEL assay while the mitochondrial transmembrane potential (Äøm) was investigated by DiOC6 staining and flow cytometry. In MDA-MB-231 cells, Clob and VUF treatments significantly decreased proliferation to 45.5±14.8% and to 76.7±5.3%, respectively. This effect was associated to a reduction in BrdU incorporation, an augment in Annexin-V and TUNEL positive cells (P<0.01), a decrease in the Äøm (81.5%) and a 2.5 fold increase in the cell senescence. In MCF-7 cells, H4R agonists inhibited proliferation by 50% increasing the exponential doubling time from 32.6 h to 46.4 h and 47.3 h in Clob and VUF treated cells, respectively. The negative effect on proliferation was related to an increase in Annexin-V and TUNEL positive cells (P<0.01), a decrease in the Äøm (59.5%) and a 2 fold increase in cell senescence. We conclude that the H4R is involved in the regulation of breast cancer cell proliferation, apoptosis and senescence.