Citations

Abstract T cell responses are compromised in the elderly. The B7-CD28 family receptors are critical in the regulation of immune responses. We evaluated whether the B7-family and CD28-family receptors were differentially expressed in dendritic cells, macrophages, and CD4+ and CD8+ T cells from young and old mice, which could contribute to the immune dysfunction in the old. Although most of the receptors were equally expressed in all cells, >85% of the old naive CD8+ T cells expressed B7-H1 compared with 25% in the young. Considering that B7-H1 negatively regulates immune responses, we hypothesized that expression of B7-H1 would downregulate the function of old CD8+ T cells. Old CD8+ T cells showed reduced ability to proliferate, but blockade of B7-H1 restored the proliferative capacity of old CD8+ T cells to a level similar to young CD8+ T cells. In vivo blockade of B7-H1 restored antitumor responses against the B7-H1− BM-185–enhanced GFP tumor, such that old animals responded with the same efficiency as young mice. Our data also indicate that old CD8+ T cells express lower levels of TCR compared with young CD8+ T cells. However, following antigenic stimulation in the presence of B7-H1 blockade, the levels of TCR expression were restored in old CD8+ T cells, which correlated with stronger T cell activation. These studies demonstrated that expression of B7-H1 in old CD8+ T cells impairs the proper activation of these cells and that blockade of B7-H1 could be critical to optimally stimulate a CD8 T cell response in the old.

Abstract Tissue injury triggers reparative processes that often involve endothelial progenitor cells (EPCs) recruitment. We hypothesized that atherosclerotic renal artery stenosis (ARAS) activates homing signals that would be detectable in both the kidney and EPCs, and attenuated on renal repair using selective cell-based therapy. Pigs were treated with intrarenal autologous EPC after 6 weeks of ARAS. Four weeks later, expression of homing-related signals in EPC and kidney, single kidney function, microvascular (MV) density, and morphology were compared with untreated ARAS and normal control pigs (n = 7 each). Compared with normal EPC, EPC from ARAS pigs showed increased stromal cell-derived factor (SDF)-1, angiopoietin-1, Tie-2, and c-kit expression, but downregulation of erythropoietin (EPO) and its receptor. The ARAS kidney released the c-kit-ligand stem cell factor, uric acid, and EPO, and upregulated integrin β2, suggesting activation of corresponding homing signaling. However, angiopoietin-1 and SDF-1/CXCR4 were not elevated. Administration of EPC into the stenotic kidney restored angiogenic activity, improved MV density, renal hemodynamics and function, decreased fibrosis and oxidative stress, and attenuated endogenous injury signals. The ARAS kidney releases specific homing signals corresponding to cognate receptors expressed by EPC. EPC show plasticity for organ-specific recruitment strategies, which are upregulated in early atherosclerosis. EPC are renoprotective as they attenuated renal dysfunction and damage in chronic ARAS, and consequently decreased the injury signals. Importantly, manipulation of homing signals may potentially allow therapeutic opportunities to increase endogenous EPC recruitment.

AbstractExperience with new‐born screening (NBS) for disorders of fatty‐acid oxidation (FAOD) is now becoming available from an increasing number of programs worldwide. The spectrum of FAOD differs widely between ethnic groups. Incidence calculations from reports from Australia, Germany, and the USA of a total of 5,256,999 newborns give a combined incidence of all FAOD of approximately 1:9,300. However, it appears to be much lower in Asians. Consequently, a significant prevalence and evidence for a clear benefit of NBS is proven for medium‐chain acyl‐CoA dehydrogenase deficiency (MCAD) only in countries with a high percentage of Caucasians, with very‐long‐chain acyl‐CoA dehydrogenase deficiency (VLCAD) and long‐chain 3‐hydroxy acyl‐CoA dehydrogenase deficiency (LCHAD) being additional candidates. The long‐term benefit for many disorders has still to be evaluated and will require international collaboration, especially for the rarest disorders. Short‐chain acyl‐CoA dehydrogenase deficiency (SCAD) [as well as Systemic carnitine transporter deficiency (CTD) and dienoyl‐CoA reductase deficiency (DE‐RED)] are conditions of uncertain clinical significance, but most FAOD have a spectrum of clinical presentations (healthy–death). Confirmatory diagnostic procedures should be agreed upon to ensure international comparability of results and evidence‐based modifications. The case of short‐chain acyl‐CoA dehydrogenase deficiency (SCAD) deficiency shows that even inclusion of conditions without a clearly known natural course may prove useful with respect to gain of knowledge and consecutive exclusion of a biochemical abnormality without clinical significance, although this line of argument implies the existence of structured follow‐up programs and bears ethical controversies. As a final conclusion, the accumulated evidence suggests all FAOD should to be included into tandem mass spectrometry (MS/MS)‐based NBS programs provided sufficient laboratory performance is guaranteed.

Abstract Epidermal growth factor receptor (EGFR) vIII is a mutated EGFR that is frequently overexpressed in glioblastomas and implicated in response to receptor tyrosine kinase inhibitors. In this study, we investigate the effect of ZD6474 (ZACTIMA, vandetanib), a dual inhibitor for vascular endothelial growth factor receptor 2 and EGFR on growth and angiogenesis of gliomas expressing EGFRvIII. We used two glioma xenograft models, U87MG cells overexpressing EGFRvIII and short-term cultured primary glioma GBM8 cells with EGFRvIII. ZD6474 inhibited tumor growth and angiogenesis and induced cell apoptosis in various brain gliomas. Moreover, significant inhibition of EGFRvIII-expressing U87MG and GBM8 gliomas was observed compared with their controls. Magnetic resonance imaging analysis using the apparent diffusion coefficient and three-dimensional T2*weighed measurements validated ZD6474 inhibition on tumor growth and angiogenesis in EGFRvIII-expressing GBM8 gliomas. Mechanistically, ZD6474 shows better inhibition of cell growth and survival of U87MG/EGFRvIII, GBM6, and GBM8 cells that express EGFRvIII than U87MG or GBM14 cells that have nondetectable EGFRvIII through attenuation of activated phosphorylation of signal transducer and activator of transcription 3, Akt, and Bcl-XL expression. Albeit in lesser extent, ZD6474 also displays suppressions of U87MG/EGFR and GBM12 cells that overexpress wild-type EGFR. Additionally, ZD6474 inhibits activation of extracellular signal-regulated kinase 1/2 in both types of cells, and expression of a constitutively active phosphoinositide 3-kinases partially rescued ZD6474 inhibition in U87MG/EGFRvIII cells. Taken together, these data show that ZD6474 significantly inhibited growth and angiogenesis of gliomas expressing EGFRvIII by specifically blocking EGFRvIII-activated signaling mediators, suggesting a potential application of ZD6474 in treatments for glioblastomas that overexpress EGFRvIII. Mol Cancer Ther; 9(4); 929–41. ©2010 AACR.

Purpose Patient adherence is critical in evaluating the effectiveness of an oral therapy. We sought to measure adherence among women randomly assigned to capecitabine in a preplanned substudy of a multicenter clinical trial. Patients and Methods Cancer and Leukemia Group B study CALGB 49907 was a randomly assigned trial comparing standard chemotherapy versus oral chemotherapy with capecitabine in patients age 65 years or older with early-stage breast cancer. We used microelectronic monitoring system (MEMS) caps on participants' capecitabine bottles to record pill bottle openings. Capecitabine was given in two divided daily doses for 14 consecutive days of a 21-day cycle for six cycles. Adherence was calculated as the number of doses taken divided by doses expected, taking into account toxicity-related dosing changes. A participant was defined as adherent if 80% or more of expected doses were recorded by MEMS. Results Overall, 161 patients were enrolled. Median age was 71 years (range, 65 to 89 years); 124 patients (83%) persisted with capecitabine to completion of planned protocol therapy. Adherence was 78% across all cycles, and adherence did not vary by cycle (P = .32). Twenty-five percent of participants took fewer than 80% of expected doses and were nonadherent. In a logistic regression model, participants with node-negative disease (P = .01) and mastectomy (P = .01) were more likely to be nonadherent. Adherence was not related to age, tumor stage, or hormone receptor status. Adherence was not significantly associated with relapse-free survival or grade 3 or 4 toxicity. Conclusion Most older women with early-stage breast cancer were adherent to short-term oral chemotherapy in a randomized clinical trial. Age was not associated with adherence.