The heat shock protein 90 inhibitor 17-AAG induces cell cycle arrest and apoptosis in mantle cell lymphoma cell lines by depleting cyclin D1, Akt, Bid and activating caspase 9

Mantle cell lymphoma (MCL), a distinct type of non-Hodgkin lymphoma, is characterised by the overexpression of cyclin D1. Heat shock protein 90 (HSP90) is a molecular chaperon to proteins that regulate cell cycle and survival. 17-allylamino-17-demethoxy-geldanamycin (17-AAG), a HSP90 small molecule inhibitor, induced G_0/1 cell cycle arrest and cell death in a dose- and time-dependent manner in MCL cell lines. This effect was associated with the downregulation of cyclin D1, cdk4 and Akt, depletion of Bid, and activation of the intrinsic/mitochondrial caspase pathway. These data suggest that 17-AAG may have a potential therapeutic value in patients with MCL.