Hypoxia is a common feature of tumors that occurs across a wide variety of malignancies. Multiple myeloma is an incurable malignant disorder of plasma cells in the bone marrow. Although bone marrow hypoxia is crucial for normal hematopoiesis, the effect of hypoxia on multiple myeloma is poorly understood. In this study, we demonstrated that cobalt...

YM155, a novel small molecule inhibitor of survivin, shows broad anticancer activity. Here, we have focused on the cytotoxic activity of YM155 against multiple myeloma (MM) including cytokinetically quiescent (G0/G1) cells and bortezomib resistant cells. YM155 strongly inhibited the growth of MM cell lines with the IC50 value of below 10 nM. YM155 also showed potent anti-myeloma activity in mou...

Purpose: The variable regions of Ig (idiotype, Id) expressed by malignant B cells can be used as tumorspecific antigens that induce humoral and cellular immunity. However, epitopes derived from Id that stimulate human CD8þ T-cell immunity are incompletely characterized. Experimental Design: The clonal Ig VL of human myeloma cell line U266 and five primary B-cell tumors were sequenced, and pepti...

Thalidomide (Thal), a novel agent in the treatment of multiple myeloma, is presumed to act through a variety of mechanisms. In the present study, we examined the relationship between fibroblast growth factor receptor 3 (FGFR3) expression and the therapeutic effect of Thal. The DNA synthesis of KMS-11 clone, which overexpresses FGFR3, was inhibited by Thal in a dose-dependent manner; whereas U26...

Background: Beta-hydroxyisovalerylshikonin (beta-HIVS) is a compound isolated from the traditional oriental medicinal herb lithospermum radix. This drug exerts a role as an ATP non-competitive inhibitor of Protein-Tyrosine Kinases (PTKs) and shows great potential for induction of apoptosis against human cancer cells. We investigated the effect of beta-HIVS on multiple myeloma U266 cells and cla...

Despite great advance in multiple myeloma (MM) treatment since 2000s, it is still an incurable disease and novel therapies are welcome. Therefore, the purpose of this study was to explore MM plasma cells' (MM-PC) proteome, in comparison with their normal counterparts (derived from palatine tonsils of normal donors, ND-PC), in order to find potential therapeutic targets expressed on the surface ...

In this study, 2-aminophenoxazine-3-one (Phx-3) exhibited a potent cell growth inhibitory effect with apoptotic features in a dose-dependent manner in various cancer cell lines tested. Comparison of the expression profiles of endoplasmic reticulum (ER) stress-related genes in U266 multiple myeloma cells after treatment with Phx-3 and the ER stress inducers tunicamycin (TNM) and thapsigargin (TP...

Bortezomib (BZ), a first line 26S proteasome inhibitor, induces a potent cytocidal effect with caspase-3 activation in multiple myeloma (MM) cell lines. Since IκBα is a substrate of the proteasome, the initial rationale for using BZ in MM has been to inhibit NF-κB. However, BZ rather activated NF-κB activity in U266 cells. BZ induces autophagy as well as endoplasmic reticulum (ER) stress in var...

Interactions between UCN-01 and HMG-CoA reductase inhibitors (ie, statins) have been examined in human leukemia and myeloma cells. Exposure of U937 and U266 cells to minimally toxic concentrations of UCN-01 and various statins (eg, lovastatin, simvastatin, or fluvastatin) dramatically increased mitochondrial dysfunction, caspase activation, and apoptosis. Comparable effects were observed in oth...

Sorcin is a penta-EF hand calcium binding protein, which is involved in the resistance to chemotherapeutics in cancer cells, and is overexpressed in various cancer cells. However, tumor relapse combined with the development of drug resistance remains a significant problem. Here, we demonstrated that silencing of Sorcin in chemotherapy resistance myeloma U266/ADM and KM3/DDP cell lines resulted ...