Citations

Mice lacking the membrane tyrosine kinase c-mer have been shown to have altered macro-phage cytokine production and defective phagocytosis of apoptotic cells despite normal phagocytosis of other particles. We show here that c-mer–deficient mice have impaired clearance of infused apoptotic cells and that they develop progressive lupus-like autoimmunity, with antibodies to chromatin, DNA, and IgG. The autoimmunity appears to be driven by endogenous antigens, with little polyclonal B cell activation. These mice should be an excellent model for studying the role of apoptotic debris as an immunogenic stimulus for systemic autoimmunity.

Exchange of information between the nucleus and cytosol depends on the metabolic state of the cell, yet the energy-supply pathways to the nuclear compartment are unknown. Here, the energetics of nucleocytoplasmic communication was determined by imaging import of a constitutive nuclear protein histone H1. Translocation of H1 through nuclear pores in cardiac cells relied on ATP supplied by mitochondrial oxidative phosphorylation, but not by glycolysis. Although mitochondria clustered around the nucleus, reducing the distance for energy transfer, simple nucleotide diffusion was insufficient to meet the energetic demands of nuclear transport. Rather, the integrated phosphotransfer network was required for delivery of high-energy phosphoryls from mitochondria to the nucleus. In neonatal cardiomyocytes with low creatine kinase activity, inhibition of adenylate kinase-catalyzed phosphotransfer abolished nuclear import. With deficient adenylate kinase, nucleoside diphosphate kinase, which secures phosphoryl exchange between ATP and GTP, was unable to sustain nuclear import. Up-regulation of creatine kinase phosphotransfer, to mimic metabolic conditions of adult cardiac cells, rescued H1 import, suggesting a developmental plasticity of the cellular energetic system. Thus, mitochondrial oxidative phosphorylation coupled with phosphotransfer relays provides an efficient energetic unit in support of nuclear transport.

PURPOSE: Radioimmunotherapy combines biologic and radiolytic mechanisms to target and destroy tumor cells, thus offering a needed therapeutic alternative for refractory non-Hodgkin’s lymphoma (NHL) patients. This phase III randomized study compares the novel radioimmunotherapy yttrium-90 (90Y) ibritumomab tiuxetan with a control immunotherapy, rituximab, in 143 patients with relapsed or refractory low-grade, follicular, or transformed CD20+transformed NHL.PATIENTS AND METHODS: Patients received either a single intravenous (IV) dose of90Y ibritumomab tiuxetan 0.4 mCi/kg (n = 73) or rituximab 375 mg/m2IV weekly for four doses (n = 70). The radioimmunotherapy group was pretreated with two rituximab doses (250 mg/m2) to improve biodistribution and one dose of indium-111 ibritumomab tiuxetan for imaging and dosimetry. The primary end point, overall response rate (ORR), was assessed by an independent, blinded, lymphoma expert panel.RESULTS: ORR was 80% for the90Y ibritumomab tiuxetan group versus 56% for the rituximab group (P = .002). Complete response (CR) rates were 30% and 16% in the90Y ibritumomab tiuxetan and rituximab groups, respectively (P = .04). An additional 4% achieved an unconfirmed CR in each group. Kaplan-Meier estimated median duration of response was 14.2 months in the90Y ibritumomab tiuxetan group versus 12.1 months in the control group (P = .6), and time to progression was 11.2 versus 10.1 months (P = .173) in all patients. Durable responses of ≥ 6 months were 64% versus 47% (P = .030). Reversible myelosuppression was the primary toxicity noted with90Y ibritumomab tiuxetan.CONCLUSION: Radioimmunotherapy with90Y ibritumomab tiuxetan is well tolerated and produces statistically and clinically significant higher ORR and CR compared with rituximab alone.

PURPOSE: To determine whether the source of autologous hematopoietic stem cells altered the clinical outcomes of patients undergoing high-dose chemotherapy and hematopoietic stem-cell transplantation (HSCT) for aggressive non-Hodgkin’s lymphoma (NHL). PATIENTS AND METHODS: Of 105 high-risk, persistent, or relapsed NHL patients slated for an autologous HSCT entered onto this trial, 93 eligible patients were randomized to receive cytokine-naive autologous bone marrow transplantation (ABMT) (n = 46) or mobilized peripheral-blood stem-cell transplantation (PBSCT) (n = 47). All patients received carmustine, etoposide, cytarabine, and cyclophosphamide as the conditioning regimen. PBSCT patients also received identical mobilization with granulocyte colony-stimulating factor (G-CSF) 10 μg/kg/d, and both groups received G-CSF 5 μg/kg/d after the infusion of the stem-cell product until neutrophil engraftment. RESULTS: PBSCT patients had significantly faster engraftment of all cell lineages: median time to absolute neutrophil count ≥ 500/μL, 10 days versus 13 days on the ABMT arm; median time to platelet count greater than 20,000/μL untransfused, 11 days versus 15 days on the ABMT arm; and median time to RBC transfusion independence, 8 days versus 16 days on the ABMT arm. The complete response rate was 72% for PBSCT and 54% for ABMT. The death rate before posttransplant day 100 was 2% on the ABMT arm and 6% on PBSCT arm. Event-free survival was 37% for PBSCT and 37% for ABMT. However, overall survival for PBSCT was 61% compared with 43% for ABMT. CONCLUSION: Patients with aggressive NHL receiving HSCT randomized to PBSCT demonstrated improved neutrophil engraftment and platelet and RBC transfusion independence. The complete response rate and EFS were not statistically different by randomization arm. Patients whose harvests were positive for minimal residual disease by molecular analysis had poorer EFS.

PURPOSE: The gastrointestinal Intergroup studied postoperative adjuvant chemotherapy and radiation therapy in patients with T3/4 and N+ rectal cancer after potentially curative surgery to try to improve chemotherapy and to determine the risk of systemic and local failure. PATIENTS AND METHODS: All patients had a potentially curative surgical resection and were treated with two cycles of chemotherapy followed by chemoradiation therapy and two additional cycles of chemotherapy. Chemotherapy regimens were bolus fluorouracil (5-FU), 5-FU and leucovorin, 5-FU and levamisole, and 5-FU, leucovorin, and levamisole. Pelvic irradiation was given to a dose of 45 Gy to the whole pelvis and a boost to 50.4 to 54 Gy. RESULTS: One thousand six hundred ninety-five patients were entered and fully assessable, with a median follow-up of 7.4 years. There was no difference in overall survival (OS) or disease-free survival (DFS) by drug regimen. DFS and OS decreased between years 5 and 7 (from 54% to 50% and 64% to 56%, respectively), although recurrence-free rates had only a small decrease. The local recurrence rate was 14% (9% in low-risk [T1 to N2+] and 18% in high-risk patients [T3N+, T4N]). Overall, 7-year survival rates were 70% and 45% for the low-risk and high-risk groups, respectively. Males had a poorer overall survival rate than females. CONCLUSION: There is no advantage to leucovorin- or levamisole-containing regimens over bolus 5-FU alone in the adjuvant treatment of rectal cancer when combined with irradiation. Local and distant recurrence rates are still high, especially in T3N+ and T4 patients, even with full adjuvant chemoradiation therapy.

PURPOSE: To evaluate the value of thymidylate synthase (TS), Ki-67, and p53 as prognostic markers in patients with Dukes’ B2 and C colon carcinoma. METHODS: We conducted a retrospective analysis to evaluate the prognostic value of TS, Ki-67, and p53 in 465 patients with Dukes’ B2 (220 patients) or Dukes’ C (245 patients) colon carcinoma. Patients represent a nonrandom subset obtained from five randomized phase III trials and were treated with either surgery alone (151 patients) or surgery plus fluorouracil-based chemotherapy (314 patients). All three markers were assayed using immunohistochemical techniques. RESULTS: With a minimum follow-up of 5 years, our retrospective analysis failed to demonstrate a consistent and significant association between TS, Ki-67, or p53 and either disease-free survival or overall survival. Exploratory analyses did not reveal a convincing explanation for these results that are in conflict with the published literature. Notable interactions were observed. In particular, high Ki-67 levels were associated with increased (decreased) survival in patients with low (high) TS intensity. Patients whose tumors stained positively for p53 seemed to benefit substantially from the use of adjuvant chemotherapy compared with those who were not treated (P = .05). CONCLUSION: This retrospective investigation failed to demonstrate a significant association between TS, Ki-67, or p53 staining and clinical outcome.

Background — Obstructive sleep apnea (OSA) has been increasingly linked to cardiovascular and cerebrovascular disease. Inflammatory processes associated with OSA may contribute to cardiovascular morbidity in these patients. We tested the hypothesis that OSA patients have increased plasma C-reactive protein (CRP). Methods and Results — We studied 22 patients (18 males and 4 females) with newly diagnosed OSA, who were free of other diseases, had never been treated for OSA, and were taking no medications. We compared CRP measurements in these patients to measurements obtained in 20 control subjects (15 males and 5 females) who were matched for age and body mass index, and in whom occult OSA was excluded. Plasma CRP levels were significantly higher in patients with OSA than in controls (median [range] 0.33 [0.09 to 2.73] versus 0.09 [0.02 to 0.9] mg/dL, P <0.0003). In multivariate analysis, CRP levels were independently associated with OSA severity (F=6.8, P =0.032). Conclusions — OSA is associated with elevated levels of CRP, a marker of inflammation and of cardiovascular risk. The severity of OSA is proportional to the CRP level.

Background — Despite the common occurrence of aortic stenosis, the cellular causes of the disorder are unknown, in part because of the absence of experimental models. We hypothesized that atherosclerosis and early bone matrix expression in the aortic valve occurs secondary to experimental hypercholesterolemia and that treatment with atorvastatin modifies this transformation. Methods and Results — To test this hypothesis, we developed an experimental hypercholesterolemic rabbit model. New Zealand White rabbits (n=48) were studied: group 1 (n=16), normal diet; group 2 (n=16), 1% (wt/wt) cholesterol diet; and group 3 (n=16), 1% (wt/wt) cholesterol diet plus atorvastatin (3 mg/kg per day). The aortic valves were examined with hematoxylin and eosin stain, Masson trichrome, macrophage (RAM 11), proliferation cell nuclear antigen (PCNA), and osteopontin immunostains. Cholesterol and highly sensitive C-reactive protein (hsCRP) serum levels were obtained by standard assays. Computerized morphometry and digital image analysis were performed for quantifying PCNA (% area). Electron microscopy and immunogold labeling were performed for osteopontin. Semiquantitative RT-PCR was performed for the osteoblast bone markers [alkaline phosphatase, osteopontin, and osteoblast lineage-specific transcription factor ( Cbfa-1 )]. There was an increase in cholesterol, hsCRP, PCNA, RAM 11, and osteopontin and osteoblast gene markers (alkaline phosphatase, osteopontin, and Cbfa-1 ) in the cholesterol-fed rabbits compared with control rabbits. All markers except hsCRP were reduced by atorvastatin. Conclusions — These findings of increased macrophages, PCNA levels, and bone matrix proteins in the aortic valve during experimental hypercholesterolemia provide evidence of a proliferative atherosclerosis–like process in the aortic valve associated with the transformation to an osteoblast-like phenotype that is inhibited by atorvastatin.

Rituximab is a chimeric murine/human monoclonal antibody that binds to CD20 on B lymphocytes. Although binding of the Fab domain may induce apoptosis, the Fc domain recruits immune effector functions to mediate cell lysis. Interleukin-12 (IL-12) facilitates cytolytic T-cell responses, enhances the lytic activity of natural killer (NK) cells, and induces the secretion of interferon γ (IFN-γ) by both T and NK cells. Therefore, the hypothesis was considered that combining IL-12 with rituximab would augment the immune-mediated cell lysis induced by rituximab. A phase 1 study of IL-12 in combination with rituximab was conducted in 43 adults with B-cell lymphoma to determine the optimal immunologic dose of this combination. Rituximab was administered at a dose of 375 mg/m2 by intravenous infusion weekly for 4 weeks, and IL-12 was given subcutaneously twice weekly. The starting dose of IL-12 was 30 ng/kg and this was escalated to 500 ng/kg. Constitutional symptoms and liver enzyme elevations at 500 ng/kg of IL-12 were dose limiting. A greater than 20-fold increase in the serum levels of IFN-γ and a 2.5- to 5-fold increase in inducible protein 10 (IP-10) levels was seen at IL-12 doses of 100 ng/kg or greater. Objective responses occurred in 29 of the 43 patients (69%), with 8 of 11 complete responses seen at IL-12 doses of 300 ng/kg or greater. The optimal immunologic dose of IL-12 in combination with rituximab was determined to be 300 ng/kg subcutaneously twice weekly starting on day 2. These data suggest that IL-12 and rituximab is an active combination and further studies of this combination in B-cell non-Hodgkin lymphoma are warranted.

Primary systemic amyloidosis (AL) is a plasma cell (PC) dyscrasia with clinical similarities to multiple myeloma (MM) and monoclonal gammopathy of undetermined significance (MGUS), but its molecular basis is poorly understood. Translocations at the immunoglobulin heavy-chain (IgH) locus, 14q32, are likely early genetic events in both MM and MGUS and involve several nonrandom, recurrent, partner chromosomes such as 11q13, 16q23, and 4p16.3. Given the similarities between MM, MGUS, and AL, bone marrow clonal PCs were evaluated in 29 patients with AL using interphase fluorescence in situ hybridization (FISH) combined with immunofluorescence detection of the cytoplasmic light-chain (cIg-FISH) for the presence of 14q32 translocations and the t(11;14)(q13;q32). Of 29 patients studied, 21 (72.4%) showed results compatible with the presence of a 14q32 translocation, and 16 (76.2%) of those had translocation (11;14)(q13;q32) for an overall prevalence of the abnormality of 55%. IgH translocations are common in AL, especially the t(11;14)(q13;q32).