The pan-histone deacetylase inhibitor CR2408 disrupts cell cycle progression, diminishes proliferation and causes apoptosis in multiple myeloma cells.

In view of the fact that histone deacetylases (HDACs) are promising targets for myeloma therapy, we investigated the effects of the HDAC inhibitor CR2408 on multiple myeloma (MM) cells in vitro. CR2408 is a direct pan-HDAC inhibitor and inhibits all known 11 HDACs with a 50% inhibitory concentration (IC(50) ) of 12 nmol/l (HDAC 6) to 520 nmol/l (HDAC 8). Correspondingly, CR2408 induces hyperacetylation of histone H4, inhibits cell growth and strongly induces apoptosis (IC(50) =0.

Simultaneous targeting of PI3K and mTOR with NVP-BGT226 is highly effective in multiple myeloma.

Multiple myeloma is still uncurable. Myeloma cells become resistant to common drugs and patients eventually die of tumour progression. Therefore, new targets and drugs are urgently needed.

Peripheral T-cell lymphoma with progression to a clonally related, Epstein Barr virus+, cytotoxic aggressive T-cell lymphoma: evidence for secondary EBV infection of an established malignant T-cell clone.

We report a case of primary Epstein Barr virus (EBV) negative peripheral T-cell lymphoma (PTCL) NOS in a 56-year-old female who-after an initially indolent course - simultaneously developed an aggressive, EBV+ cytotoxic large T-cell lymphoma, clonally related to the primary PTCL, and an EBV+, clonal large B-cell lymphoproliferation. The initial, EBV-negative PTCL had shown some features of angioimmunoblastic T-cell lymphoma and had responded well to steroid therapy. Two years later, rapidly fatal, progressive disease with multivisceral involvement developed.

The novel inhibitor of histone deacetylase resminostat (RAS2410) inhibits proliferation and induces apoptosis in multiple myeloma (MM) cells.

Inhibition of histone deacetylase (HDAC) is a promising mechanism for novel, anti-myeloma agents. We investigated the effects of the novel HDAC inhibitor resminostat on multiple myeloma (MM) cells in vitro. Resminostat is a potent inhibitor of HDACs 1, 3 and 6 [50% inhibitory concentration (IC50)=43-72 nmol/l] representing HDAC classes I and II and induces hyperacetylation of histone H4 in MM cells.

The novel, proteasome-independent NF-kappaB inhibitor V1810 induces apoptosis and cell cycle arrest in multiple myeloma and overcomes NF-kappaB-mediated drug resistance.

Evidence is increasing that aberrant NF-kappaB activation is crucial for multiple myeloma pathophysiology and a promising target for new antimyeloma therapies. In this study, we assessed the in vitro antimyeloma activity of the novel NF-kappaB inhibitor V1810. Pharmacokinetics and toxicity were studied in vivo.

Myeloma cell growth inhibition is augmented by synchronous inhibition of the insulin-like growth factor-1 receptor by NVP-AEW541 and inhibition of mammalian target of rapamycin by Rad001.

Multiple myeloma is still incurable. Myeloma cells become resistant to common drugs and patients eventually die of tumour progression. Therefore, new targets and drugs are needed immediately.

Dihydroorotate dehydrogenase inhibitor A771726 (leflunomide) induces apoptosis and diminishes proliferation of multiple myeloma cells.

Multiple myeloma is still an incurable disease; therefore, new therapeutics are urgently needed. A771726 is the active metabolite of the immunosuppressive drug leflunomide, which is currently applied in the treatment of rheumatoid arthritis, BK virus nephropathy, and cytomegaly viremia. Here, we show that dihydroorotate dehydrogenase (DHODH) is commonly expressed in multiple myeloma cell lines and primary multiple myeloma cells.

The peptide-semicarbazone S-2209, a representative of a new class of proteasome inhibitors, induces apoptosis and cell growth arrest in multiple myeloma cells.

Bortezomib is the first approved member of a new class of anti-myeloma agents, the proteasome inhibitors. Further proteasome inhibitors are needed to optimise this promising treatment option. S-2209 [1-[1-{1-[(2,4-Dioxo-imidazolidin-1-ylimino)-methyl]-2-phenyl-ethylcarbamoyl}-2-(1H-indol-3-yl)-ethylcarbamoyl]-2-(1H-indol)] inhibits the chymotryptic activity of the human 20S proteasome (half maximal effective concentration, IC(50) approximately 220 nmol/l) which was determined by a proteasome inhibition assay.

The novel orally bioavailable inhibitor of phosphoinositol-3-kinase and mammalian target of rapamycin, NVP-BEZ235, inhibits growth and proliferation in multiple myeloma.

NVP-BEZ235 is a new inhibitor of phosphoinositol-3-kinase (PI3 kinase) and mammalian target of rapamycin (mTOR) whose efficacy in advanced solid tumours is currently being evaluated in a phase I/II clinical trial. Here we show that NVP-BEZ235 inhibits growth in common myeloma cell lines as well as primary myeloma cells at nanomolar concentrations in a time and dose dependent fashion. Further experiments revealed induction of apoptosis in three of four cell lines.

Alkylating agents induce activation of NFkappaB in multiple myeloma cells.

Multiple myeloma is still not curable and drug combination strategies are currently being evaluated in order to achieve high remission rates with tolerable toxicity. Bortezomib has been shown to exert inhibitory effects on NFkappaB activity. NFkappaB in turn is known to be activated by cytokines, growth factors and by cellular adhesion to bone marrow stromal cells and represents an important mediator of primary and secondary drug resistance in multiple myeloma that confers to proliferation and survival.

Inhibitors of protein kinase C sensitise multiple myeloma cells to common genotoxic drugs.

Objectives: Despite high dose treatment regimes multiple myeloma (MM) disease is still not curable. Patients become resistant to cytotoxic drugs and die of disease progression. Therefore, besides new cytotoxic compounds drug sensitisers are urgently needed.

Inhibition of lymphocyte function associated antigen 1 by LFA878 induces apoptosis in multiple myeloma cells and is associated with downregulation of the focal adhesion kinase/phosphatidylinositol 3 kinase/Akt pathway.

Multiple myeloma (MM) is still an incurable disease and adhesion of MM cells to bone marrow stromal cells is one of the hallmarks of the disease. Lymphocyte function associated antigen 1 (LFA-1) is an adhesion molecule that mediates lymphocyte adhesion, but its role in MM is only poorly understood. The aim of the presented study was to improve knowledge on LFA-1 and associated pathways in MM for the development of molecular targeted therapies.

Activation of adenosine monophosphate activated protein kinase inhibits growth of multiple myeloma cells.

The role of adenosine monophosphate activated protein kinase (AMPK) in regulating multiple myeloma (MM) cell growth is not yet clear. In this study, we show that the AMPK activators 5-aminoimidazole-4-carboxamide riboside (AICAr) and D942 inhibit cell growth in MM cell lines. AICAr also induced an S-phase cell cycle arrest in all four tested cell lines and led to phosphorylation and thus activation of AMPK.

Bendamustine induces G2 cell cycle arrest and apoptosis in myeloma cells: the role of ATM-Chk2-Cdc25A and ATM-p53-p21-pathways.

Purpose: Multiple myeloma is a fatal hematological disease caused by malignant transformation of plasma cells. Bendamustine has been proven to be a potent alternative to melphalan in phase 3 studies, yet its molecular mode of action is still poorly understood.

Methods: The four-myeloma cell lines NCI-H929, OPM-2, RPMI-8226, and U266 were cultured in vitro.

Inhibition of adenosine monophosphate-activated protein kinase induces apoptosis in multiple myeloma cells.

In this study, we show that adenosine monophosphate-activated protein kinase (AMPK) is expressed and activated in multiple myeloma cells. The inhibition of AMPK induced growth arrest and reduction of cell viability in the cell viability assay using the water-soluble tetrazolium salt 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1 assay). Induction of apoptosis was determined by annexin-V and propidium iodide staining.

Different mechanisms of cyclin D1 overexpression in multiple myeloma revealed by fluorescence in situ hybridization and quantitative analysis of mRNA levels.

The t(11;14)(q13;q32) is the most common translocation in multiple myeloma (MM), resulting in up-regulation of cyclin D1. We used a segregation fluorescence in situ hybridization (FISH) assay to detect t(11;14) breakpoints in primary MM cases and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify cyclin D1 and MYEOV (myeloma overexpressed) expression, another putative oncogene located on chromosome 11q13. High levels of cyclin D1 mRNA (cyclin D1/TBP [TATA box binding protein] ratio > 95) were found exclusively in the presence of a t(11;14) translocation (11/48 cases; P <.

Discordant bone marrow involvement in diffuse large B-cell lymphoma: comparative molecular analysis reveals a heterogeneous group of disorders.

Discordant bone marrow (BM) involvement in patients with a diagnosis of large-cell non-Hodgkin's lymphoma (NHL) is characterized by marrow infiltrates predominantly composed of small lymphoid cell, cytologically compatible with low-grade NHL. Although this phenomenon is well described morphologically, molecular data concerning the relationship of the two lesions are lacking. The aim of the study was to investigate the clonal relationship of discordant lymphoma manifestations by using immunoglobulin heavy chain gene (IgH), as well as bcl-2 rearrangements, as molecular markers.

Vascular endothelial growth factor production and regulation in human peritoneal mesothelial cells.

Background: Vascular endothelial growth factor (VEGF) was recently found in peritoneal effluents of peritoneal dialysis (PD) patients. It was suggested that human peritoneal mesothelial cells (HMC) contribute to the intraperitoneal production of VEGF, which may augment vascular permeability, vasodilation and neoangiogenesis in the peritoneal membrane. The present study was designed to assess the influence of proinflammatory cytokines, thrombin, d-glucose and glycated albumin in the regulation of VEGF synthesis in primary HMC cultures.