Sensitizing human multiple myeloma cells to the proteasome inhibitor             bortezomib by novel curcumin analogs.
The proteasome plays a vital role in the degradation of proteins involved in several pathways including the cell cycle, cellular proliferation and apoptosis and is a validated target in cancer treatment. Bortezomib (Velcade®, PS-341) is the first US FDA approved proteasome inhibitor anticancer drug used in the treatment of refractory multiple myeloma. In spite of its improved efficacy compared to alternative therapies, about 60% of patients do not respond to bortezomib due to the emergence of resistance. We hypothesized that novel small molecules could enhance the proteasome-inhibitory and anticancer activities of bortezomib in resistant multiple myeloma cells in vitro and in vivo. The dietary polyphenol curcumin has been shown to exert anti-cancer activity in several cancer cell lines, but the effects of curcumin in solid tumors have been modest primarily due to poor water solubility and poor bioavailability in tissues remote from the gastrointestinal tract. Here we show that the water-soluble analog of curcumin #12, but not curcumin, in combination with bortezomib could enhance the proteasome-inhibitory effect in multiple myeloma cells. Furthermore, the sensitivity of the myeloma cells to cytotoxic killing in the presence of otherwise sublethal concentrations of bortezomib was enhanced by incubation with the curcumin analog #12. These findings justify further investigation into those combinations that may yield potential therapeutic benefit.
Barbara Ann Karmanos Cancer Institute, Department of Oncology, School of Medicine, Wayne State University, Detroit, MI 48201-2013, USA.
Taskeen
T
Mujtaba
Jyoti
J
Kanwar
Sheng Biao
SB
Wan
Tak Hang
TH
Chan
Q Ping
QP
Dou
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001897:Boronic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D000069286:Bortezomib; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003474:Curcumin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D004357:Drug Synergism; D006801:Humans; D015151:Immunoblotting; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors; D011719:Pyrazines / Q000008:administration & dosage / Q000494:pharmacology*
D001897:Boronic Acids; D061988:Proteasome Inhibitors; D011719:Pyrazines; D000069286:Bortezomib; D046988:Proteasome Endopeptidase Complex; D003474:Curcumin