title: Blockade of ubiquitin-conjugating enzyme CDC34 enhances anti-myeloma activity of Bortezomib/Proteasome inhibitor PS-341.
abstract: The ubiquitin-conjugating enzyme CDC34 (UBC3) is linked to cell cycle progression in diverse cell types; however, its role in multiple myeloma (MM) pathogenesis is unclear. Here, we show that CDC34 is highly expressed in patient MM cells and MM cell lines versus normal cells. Blocking CDC34 using a dominant-negative strategy enhances the anti-MM activity of Bortezomib/Proteasome inhibitor PS-341, dexamethasone (Dex) and 2-Methoxyestradiol (2ME2). The expression of wild-type CDC34 reduces Dex-induced cytotoxicity in MM cells. Moreover, inhibition of CDC34 enzymatic activity abrogates interleukin-6-induced protection against Dex-induced apoptosis. Together, these findings provide evidence that (1) CDC34 expression is associated with growth and survival of MM cells and (2) blocking CDC34 activity not only enhances anti-MM activity of Bortezomib and 2ME2 but also overcomes IL-6-triggered Dex-resistance.
authors.affiliation: Department of Medical Oncology, Harvard Medical School, The Jerome Lipper Multiple Myeloma Center, Dana Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA.
authors.forename: Dharminder
authors.initials: D
authors.lastname: Chauhan
authors.forename: Guilan
authors.initials: G
authors.lastname: Li
authors.forename: Teru
authors.initials: T
authors.lastname: Hideshima
authors.forename: Klaus
authors.initials: K
authors.lastname: Podar
authors.forename: Reshma
authors.initials: R
authors.lastname: Shringarpure
authors.forename: Constantine
authors.initials: C
authors.lastname: Mitsiades
authors.forename: Nikhil
authors.initials: N
authors.lastname: Munshi
authors.forename: P Renee
authors.initials: PR
authors.lastname: Yew
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Anderson
mesh_terms: D064173:Anaphase-Promoting Complex-Cyclosome; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001897:Boronic Acids / Q000494:pharmacology*; D000069286:Bortezomib; D003907:Dexamethasone / Q000494:pharmacology; D006801:Humans; D009101:Multiple Myeloma / Q000188:drug therapy*; D011719:Pyrazines / Q000494:pharmacology*; D044763:Ubiquitin-Conjugating Enzymes; D043743:Ubiquitin-Protein Ligase Complexes / Q000037:antagonists & inhibitors*
chemical_list: D000970:Antineoplastic Agents; D001897:Boronic Acids; D011719:Pyrazines; D000069286:Bortezomib; D003907:Dexamethasone; C577447:CDC34 protein, human; D044763:Ubiquitin-Conjugating Enzymes; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome