Citations

Abstract The outcome of patients with multiple myeloma is dictated primarily by cytogenetic abnormalities and proliferative capacity of plasma cells. We studied the outcome after initial therapy with lenalidomide-dexamethasone among 100 newly diagnosed patients, risk-stratified by genetic abnormalities and plasma cell labeling index. A total of 16% had high-risk multiple myeloma, defined by the presence of hypodiploidy, del(13q) by metaphase cytogenetics, del(17p), IgH translocations [t(4;14), or t(14;16)] or plasma cell labeling index more than or equal to 3%. Response rates were 81% vs 89% in the high-risk and standard-risk groups, respectively. The median progression-free survival was shorter in the high-risk group (18.5 vs 36.5 months, P < .001), but overall survival was comparable. Because of unavailability of all tests for every patient, we separately analyzed 55 stringently classified patients, and the results were similar. In conclusion, high-risk patients achieve less durable responses with lenalidomide-dexamethasone compared with standard-risk patients; no significant differences in overall survival are apparent so far. These results need confirmation in larger, prospectively designed studies.

Abstract A proliferation-inducing ligand (APRIL), as well as its receptors transmembrane activator and calcium-modulating cyclophilin ligand (CAML) interactor (TACI) and B-cell maturation antigen (BCMA), has been shown to be important in B-cell biology, and overexpression of APRIL in mice results in development of lymphoma. Limited data are available on APRIL-specific signaling responses, but knockout models suggest that signaling through TACI is critical to B-cell homeostasis. To better understand the mechanism by which APRIL exerts its effects and how it may contribute to lymphomagenesis, we sought to characterize the outcome of APRIL-TACI interactions. In support of murine studies, we find that APRIL induces proliferation of human patient follicular lymphoma (FL) B cells in a TACI-dependent manner. This study also shows that APRIL is expressed within the tumor microenvironment and that, upon engagement with TACI, APRIL mediates activation of the phosphatidylinositol 3-kinase (PI3K) pathway. Activation of PI3K via APRIL results in phosphorylation of Akt and mammalian target of rapamycin (mTOR) and the mTOR-specific substrates p70S6 kinase and 4E-binding protein 1 in a TACI-dependent manner. APRIL-mediated signaling also results in phosphorylation of Rb and up-regulation of cyclin D1. These studies are the first to characterize APRIL-TACI–specific signaling and suggest a role for this ligand-receptor pair in FL B-cell growth.

ABSTRACTUnderstanding innate immunity is key to improving the safety of adenovirus (Ad) vectors for systemic gene therapy. Ad has been shown to activate complement in vitro, but activation of complement after Ad injection in vivo has not been directly measured. Using complement protein C3a as a marker of complement activation, we show that types 2 and 5 human Ads cause rapid complement activation after intravenous injection in mice. Unexpectedly, the mechanisms in vivo were different than those in vitro. Antibodies were critical for the activation of complement by Ad in vitro, but antibodies were not required in vivo. The classical pathway was required in vitro, whereas complement activation in vivo involved both classical and nonclassical pathways as well as the reticuloendothelial system. Remarkably, the entry-deficient Ad mutantts1 was completely unable to activate complement in vivo even though it was fully able to activate complement in vitro. This result demonstrates that the complement system senses intravenously injected Ad primarily by detecting the effects of Ad on cells rather than through direct interaction of complement with virions. Encouragingly, shielding Ad with polyethylene glycol was effective at reducing complement activation both in vitro and in vivo. In summary, intravenously injected Ad rapidly activates complement through multiple pathways, but these pathways are different than those identified by in vitro studies. In vitro studies are poorly predictive of in vivo mechanisms because Ad virions activate complement through indirect mechanisms in vivo.

Junctophilins (JPHs) are members of a junctional membrane complex protein family important for the physical approximation of plasmalemmal and sarcoplasmic/endoplasmic reticulum membranes. As such, JPHs facilitate signal transduction in excitable cells between plasmalemmal voltage-gated calcium channels and intracellular calcium release channels. To determine the molecular evolution of the JPH gene family, we performed a phylogenetic analysis of over 60 JPH genes from over 40 species and compared conservation across species and different isoforms. We found that JPHs are evolutionary highly conserved, in particular the membrane occupation and recognition nexus motifs found in all species. Our data suggest that an ancestral form of JPH arose at the latest in a common metazoan ancestor and that in vertebrates four isoforms arose, probably following two rounds of whole genome duplications. By combining multiple prediction techniques with sequence alignments, we also postulate the presence of new important functional regions and candidate sites for posttranslational modifications. The increasing number of available sequences yields significant insight into the molecular evolution of JPHs. Our analysis is consistent with the emerging concept that JPHs serve dual important functions in excitable cells: structural assembly of junctional membrane complexes and regulation of intracellular calcium signaling pathways.

Abstract Context: The association between acute pancreatitis and primary hyperparathyroidism (PHPT) is controversial. Objective: The aim of the study was to address the incidence and disease characteristics of acute pancreatitis in PHPT from a large inception cohort of community residents. Design and Setting: Patients with acute pancreatitis were identified in an Olmsted County, Minnesota, cohort of PHPT subjects diagnosed from 1965–2001 and compared to matched control subjects. Main Outcome Measures: The estimated rate of developing acute pancreatitis was calculated by person-years method. Cox models assessed the effect of PHPT disease status on the development of acute pancreatitis. Results: Of 684 patients with PHPT, 10 patients (1.5%) developed acute pancreatitis, compared to 32 of 1364 control patients (2.3%). The estimated rate of development of acute pancreatitis in PHPT was 114 per 100,000 person-years, compared to 140 per 100,000 person-years in control subjects (P = 0.56). The estimated hazard ratio of acute pancreatitis for PHPT relative to the control subjects was 0.84 (P = 0.89). The majority of subjects with PHPT and acute pancreatitis were women (n = 7), and the mean age was 70.6 yr at the time of acute pancreatitis. PHPT was present an average of 137 months before the development of acute pancreatitis, and contributing causes for acute pancreatitis were in identified in four patients. Maximal serum calcium levels in PHPT were not significantly associated with the development of acute pancreatitis. Conclusions: Acute pancreatitis was not increased in community patients with PHPT, and therefore, there does not appear to be a causal relationship between PHPT and acute pancreatitis.

SummaryRecent reports show that 5-amino-4-imidazole carboxamide riboside (AICAR), a pharmacological activator of AMP-activated protein kinase (AMPK), inhibits the lipopolysaccharide (LPS)-induced production of proinflammatory cytokines. MRL/MPJ-Faslpr (MRL/lpr) mice show an intrinsic decreased threshold for the production of inflammatory mediators when stimulated. In our current studies, we sought to determine if AMPK activation would inhibit inflammatory mediator production in stimulated kidney mesangial cells. Cultured mesangial cells from MRL/lpr mice were treated with AICAR and stimulated with LPS/interferon (IFN)-γ. AICAR decreased dose-dependently inducible nitric oxide synthase (iNOS), cyclooxygenase-2 and interleukin-6 production in LPS/IFN-γ-stimulated mesangial cells. Mechanistically, AICAR inhibited the LPS/IFN-γ-stimulated PI3K/Akt signalling inflammatory cascade but did not affect LPS/IFN-γ-mediated inhibitory kappa B phosphorylation or nuclear factor (NF)-κB (p65) nuclear translocation. Treatment with the adenosine kinase inhibitor 5′-iodotubercidin blocked the ability of AICAR to activate AMPK and prevented AICAR from inhibiting the LPS/IFN-γ-stimulated PI3K/Akt pathway and attenuating iNOS expression. Taken together, these observations suggest that AICAR inhibits LPS/IFN-γ-induced Akt phosphorylation through AMPK activation and may serve as a potential therapeutic target in inflammatory diseases.

Mycophenolate mofetil (MMF) is effective in the treatment of patients with active systemic lupus erythematosus (SLE). We sought to evaluate its efficacy in reducing the number of disease flares in adults with SLE. For this retrospective study, all patients seen at our institution over a six year period, 1999–2005, with the diagnosis of SLE treated with MMD were identified. Data regarding lupus flare was obtained for patients at least one and up to two years prior to starting MMF. The number of flares prior to MMF therapy was compared to the number of lupus flares in the one to two year period after starting MMF. Clinical assessment was performed with the SELENA-SLEDAI instrument. Differences between groups were compared using the signed rank test. The rate of flares (flares per person-year), before and after the introduction of MMF were compared assuming the occurrence of flares followed a Poisson distribution. In the evaluable 67 patients, the mean time period of followup prior to starting MMF was 14.1 months (range 0.3–24), mean time period of follow-up after starting MMF was 14.8 months (range 1.5–24); and mean MMF dose was 1328 mg/day (range 250–3000). The mean flare rate was reduced from 8.9 to 5.3 per 10 personyears and the mean prednisone dose was reduced on average 7.3 mg/day after starting MMF therapy. MMF treatment significantly reduced the total number of lupus flares and prednisone requirements. Even with the reduction in mean daily prednisone dose, both the SLEDAI and physican global assessment also improved during MMF therapy.

ABSTRACT Planktonic and sessile susceptibilities to micafungin were determined for 30 clinical isolates of Candida albicans obtained from blood or other sterile sites. Planktonic and sessile MIC 90 s for micafungin were 0.125 and 1.0 μg/ml, respectively.

Purpose Vorinostat, a histone deacetylase inhibitor, represents a rational therapeutic target in glioblastoma multiforme (GBM). Patients and Methods Patients with recurrent GBM who had received one or fewer chemotherapy regimens for progressive disease were eligible. Vorinostat was administered at a dose of 200 mg orally twice a day for 14 days, followed by a 7-day rest period. Results A total of 66 patients were treated. Grade 3 or worse nonhematologic toxicity occurred in 26% of patients and consisted mainly of fatigue (17%), dehydration (6%), and hypernatremia (5%); grade 3 or worse hematologic toxicity occurred in 26% of patients and consisted mainly of thrombocytopenia (22%). Pharmacokinetic analysis showed lower vorinostat maximum concentration and area under the curve (0 to 24 hours) values in patients treated with enzyme-inducing anticonvulsants, although this did not reach statistical significance. The trial met the prospectively defined primary efficacy end point, with nine of the first 52 patients being progression-free at 6 months. Median overall survival from study entry was 5.7 months (range, 0.7 to 28+ months). Immunohistochemical analysis performed in paired baseline and post-vorinostat treatment samples in a separate surgical subgroup of five patients with recurrent GBM showed post treatment increase in acetylation of histones H2B and H4 (four of five patients) and of histone H3 (three of five patients). Microarray RNA analysis in the same samples showed changes in genes regulated by vorinostat, such as upregulation of E-cadherin (P = .02). Conclusion Vorinostat monotherapy is well tolerated in patients with recurrent GBM and has modest single-agent activity. Histone acetylation analysis and RNA expression profiling indicate that vorinostat in this dose and schedule affects target pathways in GBM. Additional testing of vorinostat in combination regimens is warranted.