Thalidomide (Thd), a potent teratogen, was shown to have therapeutic potential in cancer, primarily in multiple myeloma (MM), yet its mechanism of action has not been elucidated. It was recently suggested that its teratogenicity is derived from interference in expression of genes regulated by GC-rich promoters by blocking the binding of SP1 transcription factor to its motif. We explored the val...

Constitutive B-cell lymphoma 6 (Bcl-6) expression was undetectable in multiple myeloma (MM) cell lines, except U266 cells. However, it was up-regulated by coculture with bone marrow (BM) stromal cell-culture supernatant (SCCS). Bcl-6 expression in patient MM cells in the BM was positive. Anti-interleukin-6 (IL-6)-neutralizing antibody significantly blocked SCCS-induced Bcl-6 in MM cells. Indeed...

Specific intracellular signals mediated by interleukin-6 (IL-6) receptor complexes, such as signal transducer and activator of transcription 3 (STAT 3) and extracellular signal-regulated kinase (ERK) 1/2, are considered to be responsible for inducing a variety of cellular responses. In multiple myeloma, IL-6 only enhanced the proliferation of CD45+ tumor cells that harbored the IL-6-independent...

Using in vitro-growing myeloma cell lines, we studied the growth factors involved in human multiple myeloma, and particularly the potential of autocrine secretion and response to B-cell growth factor (BCGF) of RPMI 8226, the best-documented Epstein-Barr virus-negative human myeloma cell line. We found that three myeloma cell lines (RPMI 8226, U266, and IM9) produce an autostimulatory growth fac...

Multiple myeloma is a B-cell malignancy for which no curative therapies exist to date, despite enormous research efforts. The remarkable activity of the proteasome inhibitor bortezomib (PS-341, Velcade) observed in clinical trials of patients with relapsed refractory myeloma has led to investigations of the role of the ubiquitin-proteasome pathway in the pathogenesis of myeloma. Here we report ...

Multiple myeloma (MM) is an incurable hematological disorder characterized by dysregulated proliferation of terminally differentiated plasma cells. Aberrant histone acetylation has been observed in the development of numerous malignancies. Histone deacetylase inhibitors such as valproic acid (VPA) are promising drugs for cancer therapy since they have been reported to have antiproliferative eff...

The specific 26S proteasome inhibitor bortezomib (BZ) potently induces autophagy, endoplasmic reticulum (ER) stress and apoptosis in multiple myeloma (MM) cell lines (U266, IM-9 and RPMI8226). The macrolide antibiotics including concanamycin A, erythromycin (EM), clarithromycin (CAM) and azithromycin (AZM) all blocked autophagy flux, as assessed by intracellular accumulation of LC3B-II and p62....

Results IGN004 unfused antibody bound to the majority of tumor cell lines and primary tumors assessed. Against tumor antigen-positive cells in anti-proliferation experiments, IGN004 demonstrated enhanced potency compared to unfused IFNa while reduced potency was observed in cells lacking antigen expression. IGN004 treatment upregulated MHC class I, PD-L1, and OX-40L on tumor cells. In an in vit...

BACKGROUND Histone acetylation in chromatin structures plays a key role in regulation of gene transcription and is strictly controlled by histone acetyltransferase (HAT) and deacetylase (HDAC) activities. HDAC deregulation has been reported in several cancers. MATERIALS AND METHODS The expression of 10 HDACs (including HDAC class I and II) was studied by quantitative reverse transcriptionPCR ...