No abstract

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 DHODH inhibitor A771726 inhibits cell growth in common myeloma cell lines at clinically achievable concentrations in a time-and dose-dependent manner. Annexin V-FITC/ propidium iodide staining revealed induction of apoptosis of multiple myeloma cell lines and primary multiple myeloma cells. The 5-bromo-2 ¶-deoxyuridine cell proliferation assay showed that inhibition of cell growth was partly due to inhibition of multiple myeloma cell proliferation. A771726 induced G 1 cell cycle arrest via modulation of cyclin D2 and pRb expression. A771726 decreased phosphorylation of protein kinase B (Akt), p70S6K, and eukaryotic translation initiation factor 4E-binding protein-1 as shown by Western blotting experiments. Furthermore, we show that the stimulatory effect of conditioned medium of HS-5 bone marrow stromal cells on multiple myeloma cell growth is completely abrogated by A771726. In addition, synergism studies revealed synergistic and additive activity of A771726 together with the genotoxic agents melphalan, treosulfan, and doxorubicin as well as with dexamethasone and bortezomib. Taken together, we show that inhibition of DHODH by A771726/leflunomide is effective in multiple myeloma. Considering the favorable toxicity profile and the great clinical experience with leflunomide in rheumatoid arthritis, this drug represents a potential new candidate for targeted therapy in multiple myeloma. [Mol Cancer Ther 2009;8(2):366 -75]

Individual QoL as assessed by the SEIQoL-DW is unrelated to standard health-status measures such as the EORTC QLQ-C30 or the Karnofsky index. Patient-perceived iQoL in PBSCT seems to depend largely on areas others than health and physical functioning, with the family playing a prominent role.

Differentiating between positive and problematic interactions prior to PBSCT helps to recognise detrimental forms of social support. Future research should investigate the clinical implications and help tailor psychotherapeutic intervention.

In vitro statins overcome cell adhesion-mediated drug resistance at non-toxic concentrations that are achievable in humans by standard dose simvastatin. A pilot phase-II trial was initiated to determine feasibility and antimyeloma efficacy. In six myeloma patients refractory to two cycles of bortezomib or bendamustine simvastatin was concomitantly administered during further two cycles. The therapy was well tolerated without grade 3/4 toxicity. Intrapatient (cycles I/II vs. III/IV) and interpatient comparison (vs. ten patients without simvastatin) showed reduction of drug resistance by inhibition of HMG-CoA-reductase. In summary, this is the first phase II experience to study antimyeloma activity of statins in humans.