• The incidence of mutations within the MAPK pathway, the CRBN pathway, and TP53 is significantly increased in drug-refractory MM.• Mutations in CRBN might contribute to IMiD resistance in drug-refractory MM.In this study, targeted sequencing to screen 50 multidrug refractory multiple myeloma (rMM) patients was performed by using the Multiple Myeloma Mutation Panel. Patients were pretreated with both immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs), and 88%, 78%, and 68% were refractory to an IMiD, a PI, or both, respectively. The majority of patients had progressive (82%) or refractory (78%) disease immediately before sampling, with 43% being IMiD refractory and 46% being PI refractory in the most recent line of therapy. Compared with newly diagnosed MM, an increased prevalence of mutations in the Ras pathway genes KRAS, NRAS, and/or BRAF (72%), as well as TP53 (26%), CRBN (12%), and CRBN pathway genes (10%) was observed. Longitudinal analyses performed in 3 patients with CRBN mutations at time of IMiD resistance confirmed that these mutations were undetectable at earlier, IMiD-sensitive time points. Furthermore, the functional introduction of these mutations in MM cells conferred lenalidomide resistance in vitro. These data indicate a differential genetic landscape in rMM associated with drug response. (Blood. 2016;128(9):1226-1233

We aimed at demonstrating non-inferiority of bortezomib/cyclophosphamide/dexamethasone (VCD) compared to bortezomib/doxorubicin/dexamethasone (PAd) induction therapy with respect to very good partial response rates or better (⩾VGPR) in 504 newly diagnosed, transplant-eligible multiple myeloma patients. VCD was found to be non-inferior to PAd with respect to ⩾VGPR rates (37.0 versus 34.3%, P=0.001). The rates of progressive disease (PD) were 0.4% (VCD) versus 4.8% (PAd; P=0.003). In the PAd arm, 11 of 12 patients with PD had either renal impairment (creatinine ⩾2 mg/dl) at diagnosis or the cytogenetic abnormality gain 1q21, whereas no PD was observed in these subgroups in the VCD arm. Leukocytopenia/neutropenia (⩾3°) occurred more frequently in the VCD arm (35.2% versus 11.3%, P<0.001). Neuropathy rates (⩾2°) were higher in the PAd group (14.9 versus 8.4%, P=0.03). Serious adverse events, both overall and those related to thromboembolic events, were higher in the PAd group (32.7 versus 24.0%, P=0.04 and 2.8 versus 0.4%, P=0.04). Stem cell collection was not impeded by VCD. VCD is as effective as PAd in terms of achieving ⩾VGPR rates with fewer PD and has a favorable toxicity profile. Therefore, VCD is preferable to PAd as induction therapy.

The aim of this study was to investigate the effect of inhibiting a v b 3 /a v b 5 integrins by cilengitide in experimentally induced breast cancer bone metastases using noninvasive imaging techniques. For this purpose, nude rats bearing established breast cancer bone metastases were treated with cilengitide, a small molecule inhibitor of a v b 3 and a v b 5 integrins (75 mg/kg, five days per week; n 5 12 rats) and compared to vehicle-treated control rats (n 5 12). In a longitudinal study, conventional magnetic resonance imaging (MRI) and flat panel volumetric computed tomography were used to assess the volume of the soft tissue tumor and osteolysis, respectively, and dynamic contrast-enhanced (DCE-) MRI was performed to determine functional parameters of the tumor vasculature reflecting blood volume and blood vessel permeability. In rats treated with cilengitide, VCT and MRI showed that osteolytic lesions and the respective bone metastatic soft tissue tumors progressed more slowly than in vehicle-treated controls. DCE-MRI indicated a decrease in blood volume and an increase in vessel permeability and immunohistology revealed increased numbers of immature vessels in cilengitide-treated rats compared to vehicle controls. In conclusion, treatment of experimental breast cancer bone metastases with cilengitide resulted in pronounced antiresorptive and antitumor effects, suggesting that a v b 3 /a v b 5 inhibition may be a promising therapeutic approach for bone metastases.Bone metastases occur frequently in many human malignancies including breast, prostate and lung carcinoma. The stimulation of osteoclasts by tumor cells proliferating within the bone marrow is a feature of the pathogenesis of bone metastases, and both the tumor and the bone microenvironment must be considered when strategies for therapy of bone metastases are developed.1 Bisphosphonates are potent inhibitors of osteoclast function that have been used over the last decades to treat patients with bone metastases. However, they do not induce regression of bone metastases. This, together with the adverse effects associated with bisphosphonate therapy such as osteonecrosis of the jaw and renal toxicity, emphasize the urgent need for the development of novel therapies that can be applied alternatively and as combination partners to target bone metastases more effectively.Integrins are a family of 24 transmembrane proteins that integrate extracellular and intracellular activities. Besides their role in promoting physical adhesion, integrin signaling can induce cell spreading, migration, survival, proliferation and differentiation.2 The a v b 3 integrin interacts with several extracellular matrix (ECM) proteins including vitronectin, fibronectin, osteopontin, bone sialoprotein (BSP) and fibrinogen. 3,4 It is strongly expressed on activated tumor endothelial cells, whereas on resting endothelial cells in nondiseased tissues, its expression is generally low. [5][6][7] In the pathogenesis of bone metastases, osteoclasts too express a v b 3 integrin, and selec...

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Summary Enzyme promiscuity, a common property of many uridine diphosphate sugar‐dependent glycosyltransferases (UGTs) that convert small molecules, significantly hinders the identification of natural substrates and therefore the characterization of the physiological role of enzymes. In this paper we present a simple but effective strategy to identify endogenous substrates of plant UGTs using LC‐MS‐guided targeted glycoside analysis of transgenic plants. We successfully identified natural substrates of two promiscuous Nicotiana benthamiana UGTs (NbUGT73A24 and NbUGT73A25), orthologues of pathogen‐induced tobacco UGT (TOGT) from Nicotiana tabacum, which is involved in the hypersensitive reaction. While in N. tabacum, TOGT glucosylated scopoletin after treatment with salicylate, fungal elicitors and the tobacco mosaic virus, NbUGT73A24 and NbUGT73A25 produced glucosides of phytoalexin N‐feruloyl tyramine, which may strengthen cell walls to prevent the intrusion of pathogens, and flavonols after agroinfiltration of the corresponding genes in N. benthamiana. Enzymatic glucosylation of fractions of a physiological aglycone library confirmed the biological substrates of UGTs. In addition, overexpression of both genes in N. benthamiana produced clear lesions on the leaves and led to a significantly reduced content of pathogen‐induced plant metabolites such as phenylalanine and tryptophan. Our results revealed some additional biological functions of TOGT enzymes and indicated a multifunctional role of UGTs in plant resistance.

Previous studies demonstrated the relevance of focal lesions (FL) in whole-body magnetic resonance imaging (wb-MRI) at the initial workup of patients with smoldering multiple myeloma (SMM). The aim of this study was to assess the effects of longitudinal wb-MRIs on progression into multiple myeloma (MM). Sixty-three patients with SMM were analyzed who received at least two wb-MRIs for follow-up before progression into MM. Radiological progressive disease (MRI-PD) was defined as detection of new FL or increase in diameter of existing FL and a novel or progressive diffuse infiltration. Radiological stable disease (MRI-SD) was defined by no change compared with the prior MRI. Patients were followed-up every 3-6 months, including a serological and clinical evaluation. One Hundred and eighty-two wb-MRIs were analyzed. MRI-PD occurred in 31 patients (49%), and 25 (40%) patients developed MM. MRI-PD was highly significantly associated with progression into MM, regardless of findings at the initial MRI. In multivariate analysis, MRI-PD remained a risk factor, independent of relevant baseline parameters like serum monoclonal protein or ⩾95% aberrant plasma cells in the bone marrow. Patients with MRI-SD had no higher risk of progression, even when FL were present at the initial MRI. Therefore, MRI is suitable for the follow-up of patients with SMM.

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Purpose: The aim of this study was to assess the antiangiogenic treatment effects of zoledronic acid (ZA) and sunitinib malate (SM) noninvasively in experimental breast cancer bone metastases by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and vessel size imaging.Experimental Design: Nude rats bearing bone metastases after inoculation of MDA-MB-231 breast cancer cells were treated with ZA (40 μg/kg weekly; n = 8 rats), SM (20 mg/kg daily; n = 8 rats), or their combination (ZA and SM; n = 8 rats) and compared with sham-treated controls (n = 10 rats). Vascular changes in bone metastases were longitudinally imaged in vivo using DCE-MRI [amplitude (A) and exchange rate coefficient (k ep )] and vessel size imaging [blood volume (BV) and vessel size index (VI)]. In addition, antiresorptive and antitumor changes were assessed in these lesions by flat-panel volumetric computed tomography as well as morphologic MRI and diffusion-weighted imaging.Results: In bone metastases, significant changes in A, k ep , BV, and VI in accordance with decreased blood volume and vessel permeability as well as with increased mean vessel diameters were observed after application of ZA and SM as compared with controls. In this longitudinal study, antiangiogenic changes preceded the inhibition of osteolysis and antitumor effects after treatment.Conclusions: These results indicate vessel remodeling in breast cancer bone metastases on ZA and SM treatment and implicate substantial effects on imaging and treatment of malignant bone lesions. Clin Cancer Res; 16(12); 3215-25. ©2010 AACR.