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The molecular pathways implicated in multiple myeloma (MM) development are rather unknown. We studied epigenetic and DNA damage response (DDR) signals at selected model loci (N-ras, p53, d-globin) in bone marrow plasma cells and peripheral blood mononuclear cells (PBMCs) from patients with monoclonal gammopathy of undetermined significance (MGUS; n=20), smoldering/asymptomatic MM (SMM; n=29) and MM (n=18), as well as in healthy control-derived PBMCs (n=20). In both tissues analyzed, a progressive, significant increase in the looseness of local chromatin structure, gene expression levels and DNA repair efficiency from MGUS to SMM and finally to MM was observed (all P<0.002). Following ex vivo treatment with melphalan, a gradual suppression of the apoptotic pathway occurred in samples collected at different stages of myelomagenesis, with the severity and duration of the inhibition of RNA synthesis, p53 phosphorylation at serine15 and induction of apoptosis being higher in MGUS than SMM and lowest in MM patients (all P<0.0103). Interestingly, for all endpoints analyzed, a strong correlation between plasma cells and corresponding PBMCs was observed (all P<0.0003). We conclude that progressive changes in chromatin structure, transcriptional activity and DDR pathways during myelomagenesis occur in malignant plasma cells and that these changes are also reflected in PBMCs. [ABSTRACT FROM AUTHOR]

We prospectively evaluated the effect of bortezomib, thalidomide and dexamethasone (VTD) consolidation on bone metabolism of 42 myeloma patients who underwent an autologous stem cell transplantation (ASCT). VTD started on day 100 post ASCT; patients received four cycles of VTD (first block), were followed without treatment for 100 days and then received another four VTD cycles (second block). During this 12-month period, bisphosphonates were not administered. Best response included stringent complete remission (sCR) in 15 (35.7%) patients, complete response (CR) in 13 (30.9%), vgPR in 7 (16.6%), PR in 4 (9.5%), while 3 (7.1%) patients developed a progressive disease (PD). Importantly, 33.3% and 47.6% of patients improved their status of response after the first and second VTD block, respectively. VTD consolidation resulted in a significant reduction of circulating C-terminal cross-linking telopeptide of collagen type I (CTX), soluble receptor activator of the nuclear factor-kappa B ligand (sRANKL) and osteocalcin (OC), whereas bone-specific alkaline phosphatase (bALP) remained stable compared with pre-VTD values. During the study period, only one patient with a PD developed a skeletal-related event (that is, radiation to bone). The median time to progression (TTP) after ASCT was 34 months and the median time of next treatment was 40 months. We conclude that VTD consolidation post ASCT reduces bone resorption and is associated with a very low incidence of skeletal-related events (SREs) despite the absence of bisphosphonates; the later do not appear to be necessary in this context. [ABSTRACT FROM AUTHOR]

Multiple myeloma is a hematological cancer of plasma B cells and remains incurable. Two major subtypes of myeloma, hyperdiploid MM (HMM) and non-hyperdiploid MM (NHMM), have distinct chromosomal alterations and different survival outcomes. Transcription factors (TrFs) have been implicated in myeloma oncogenesis, but their dysregulation in myeloma subtypes are less studied. Here, we developed a TrF-pathway coexpression analysis to identify altered coexpression between two sample types. We apply the method to the two myeloma subtypes and the cell cycle arrest pathway, which is significantly differentially expressed between the two subtypes. We find that TrFs MYC, nuclear factor-κB and HOXA9 have significantly lower coexpression with cell cycle arrest in HMM, co-occurring with their overactivation in HMM. In contrast, TrFs ESR1 (estrogen receptor 1), SP1 and E2F1 have significantly lower coexpression with cell cycle arrest in NHMM. SP1 chromatin immunoprecipitation targets are enriched by cell cycle arrest genes. These results motivate a cooperation model of ESR1 and SP1 in regulating cell cycle arrest, and a hypothesis that their overactivation in NHMM disrupts proper regulation of cell cycle arrest. Cotargeting ESR1 and SP1 shows a synergistic effect on inhibiting myeloma proliferation in NHMM cell lines. Therefore, studying TrF-pathway coexpression dysregulation in human cancers facilitates forming novel hypotheses toward clinical utility. [ABSTRACT FROM AUTHOR]

Asymptomatic multiple myeloma (AMM) is characterized by a constant risk of progression to symptomatic myeloma. To evaluate previously recognized risk factors and to identify high-risk features we analyzed 96 patients with AMM and at least 18 months of follow-up. The progression rate at 1,2, and 3 years was 8%, 15% and 26%, respectively, and the projected 5-year progression rate was 38%. Extensive bone marrow (BM) infiltration, abnormal free light chain (FLC) ratio and serum monoclonal (M)-protein3 gr/dl were the most significant factors for progression, whereas the type of heavy (IgG vs IgA) or light chain or immunoparesis of the uninvolved immunoglobulins were not. Abnormal marrow signal of magnetic resonance imaging of the spine was associated with a significant risk of progression (median 15 months, P=0.001). Extensive BM infiltration 60% (hazard ratio, HR: 13.7, P<0.001) and FLC ratio100 (HR: 9, P=0.003) independently identified a 'very high-risk' group, which included 12.5% of patients with AMM and who progressed 18 months from initial diagnosis. Development of anemia and/or lytic bone lesions were the most common features of symptomatic progression. In conclusion, there is a subgroup of patients who have a substantial risk of progression to symptomatic disease that can be detected at diagnosis (either by extensive BM infiltration60% or FLC ratio100) and may be considered for immediate treatment. [ABSTRACT FROM AUTHOR]

The role of thalidomide, bortezomib and lenalidomide in multiple myeloma patients presenting with renal impairment was evaluated in 133 consecutive newly diagnosed patients who were treated with a novel agent-based regimen. A significant improvement of renal function (renalPR (renal partial response)) was observed in 77% of patients treated with bortezomib, in 55% with thalidomide and in 43% with lenalidomide (P=0.011). In multivariate analysis, bortezomib-based therapy was independently associated with a higher probability of renal response compared with thalidomide- or lenalidomide-based therapy. Other important variables included eGFR (estimated glomerular filtration rate) 30 ml/min, age 65 years and myeloma response. Patients treated with bortezomib achieved at least renalPR in a median of 1.34 months vs 2.7 months for thalidomide and >6 months for lenalidomide-treated patients (P=0.028). In multivariate analysis bortezomib-based therapy, higher doses of dexamethasone (160 mg during the first month of treatment), an eGFR 30 ml/min and age 65 years were independently associated with shorter time to renal response. In conclusion, bortezomib-based therapies may be more appropriate for the initial management of patients with myeloma-related renal failure; however, thalidomide and lenalidomide are also associated with significant probability of improvement of their renal function. [ABSTRACT FROM AUTHOR]

We prospectively studied the impact of several cytogenetic abnormalities (CAs) in patients with relapsed/refractory myeloma who received lenalidomide and dexamethasone (RD) with or without the addition of bortezomib (V). On the basis of the presence of previous neuropathy, 50 patients were treated with RD and 49, without preexisting neuropathy, with VRD. The overall response rate was 63%, similar for RD and VRD. Poor risk cytogenetics were associated with lower response rates in RD (P=0.01), but not in VRD (P=0.219). The median progression-free survival (PFS) was similar for RD (9 months) and VRD (7 months). The median overall survival (OS) for all patients was 16 months, with no differences between RD or VRD regimens. Poor risk cytogenetics, especially del17p, resistance to previous thalidomide, elevated lactate dehydrogenase (LDH) and presence of extramedullary disease were associated with inferior response to therapy and shorter PFS and OS. The impact of other CAs on OS was more pronounced in RD. In conclusion, the presence of CAs is an important adverse prognostic factor for patients with relapsed/refractory myeloma, but resistance to previous thalidomide, elevated LDH and presence of extramedullary disease remain of major prognostic importance. The outcome of patients with del17p remains extremely poor even with VRD combination. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in the response of the article "Diffuse MRI marrow pattern correlates with increased angiogenesis, advanced disease features and poor prognosis in newly diagnosed myeloma treated with novel agents," in April 29, 2010 issue.