Bioligical pathways of Hsp90 inhibitors in adult T cell leukemia cell lines

Heat shock protein 90 (Hsp90) is essential for the stability and the function of many client proteins, such as ERB2, C-RAF, CDK4, HIF-1 aplha and AKT. Recent reports demonstrated that inhibition of Hsp90 modulates multiple functions required for survival of human cancer, such as myeloma (Mitsiades et al, Blood:107, 1092, 2006), The aim of this study is evaluate the effect of Hsp90 inhibition, and to identify molecular pathways responsible for anti-proliferative effect on ATL cells. For Hsp90 inhibition, Geldanamycin derivates, 17AAG (17-allylamino -17-demethoxygeldanamycin) and 17DMAG (17-(dimethylaminoethylamino) 17-demethoxygeldanamycin) were used in this study. Interleukin 2-independent ATL cell lines (MT-2 and MT-4) and an interleukin 2-dependent ATL cell line (TaY-E10) were incubated, with or without Hsp90 inhibitors. Three ATL cell lines(TaY-E10, MT-2, and MT-4) were cultured in the presence or absence of Hsp90 inhibitors(17-AAG and 17-DMAG).