Second generation proteasome inhibitors: carfilzomib and immunoproteasome-specific inhibitors (IPSIs).
The ubiquitin-proteasome pathway (UPP) is an attractive chemotherapeutic target due to its intrinsically stringent regulation of cell cycle, pro-survival, and anti-apoptotic regulators that disproportionately favor survival and proliferation in malignant cells. A reversible first-in-class proteasome inhibitor, bortezomib, is Food and Drug Administration approved for multiple myeloma and relapsed/refractory mantle cell lymphoma and has proven to be extremely effective, both as a single agent and in combination. An irreversible second generation proteasome inhibitor, carfilzomib, has shown preclinical effectiveness against hematological and solid malignancies both in vitro and in vivo. Carfilzomib, a peptidyl-epoxyketone functions similarly to bortezomib through primary inhibition of chymotrypsin-like (ChT-L) activity at the b5 subunits of the core 20S proteasome. Carfilzomib is also currently achieving successful response rates within the clinical setting. In addition to conventional proteasome inhibitors, a novel approach may be to specifically target the hematological-specific immunoproteasome, thereby increasing overall effectiveness and reducing negative off-target effects. The immunoproteasome-specific inhibitor, IPSI-001, was shown to have inhibitory preference over the constitutive proteasome, and display enhanced efficiency of apoptotic induction of tumor cells from a hematologic origin. Herein, we discuss the preclinical and clinical development of carfilzomib and explore the potential of immunoproteasome-specific inhibitors, like IPSI-001, as a rational approach to exclusively target hematological malignancies.
The University of Texas M D Anderson Cancer Center, Department of Lymphoma & Myeloma, Division of Cancer Medicine, Houston, TX 77030-4009, USA. dkuhn@mdanderson.org
D J
DJ
Kuhn
R Z
RZ
Orlowski
C C
CC
Bjorklund
D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D009842:Oligopeptides / Q000627:therapeutic use*; D011480:Protease Inhibitors / Q000627:therapeutic use*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors
D000970:Antineoplastic Agents; D009842:Oligopeptides; D011480:Protease Inhibitors; D061988:Proteasome Inhibitors; C524865:carfilzomib; D046988:Proteasome Endopeptidase Complex