Evaluation of CisBio ELISA for Chromogranin A Measurement.

BACKGROUND: Chromogranin A (CgA) is a nonspecific marker for the presence of neuroendocrine tumors and neuroendocrine differentiation. The objective of this study was to evaluate the performance of the CisBio CgA ELISA. METHODS: Precision, linearity, limit of blank, and recovery of the CisBio CgA ELISA were evaluated. Seventy waste serum samples obtained from the clinical laboratory at Memorial Sloan Kettering Cancer Center were analyzed by the CisBio CgA ELISA. Results were compared to those obtained from a reference laboratory that used a proprietary ELISA for serum CgA measurement. Paired waste plasma samples were also collected from 24 of these patients to assess possible differences between CgA in serum and plasma. Finally, a preliminary reference range study was performed with samples from healthy volunteers in serum (n = 60) and plasma (n = 60). RESULTS: Within-run and between-run precision ranged from 3.0% to 5.1% and 4.8% to 12.9%, respectively. The limit of blank was 2.4 ng/mL. Recovery ranged from 88% to 102%. A statistically significant bias was observed when the CisBio CgA assay results were compared to those of a reference laboratory. Comparison of the 2 assays yielded a slope of 9.05, intercept of -18.0, and a correlation coefficient of 0.955. CgA values in serum correlated well to values measured in plasma. CONCLUSIONS: The analytical performance of the CisBio CgA ELISA was acceptable. However, CgA results are method-specific owing to lack of standardization and use of different antibodies. This lack of standardization results in several challenges for the clinical laboratory when evaluating a CgA assay.

Patient-reported Quality of Life Following Stereotactic Body Radiotherapy and Conventionally Fractionated External Beam Radiotherapy Compared with Active Surveillance Among Men with Localized Prostate Cancer.

BACKGROUND: Evidence supporting the efficacy of stereotactic body radiotherapy (SBRT) for localized prostate cancer is accumulating, but comparative studies of patient-reported quality of life (QOL) following SBRT versus conventionally fractionated external beam radiotherapy (EBRT) or active surveillance (AS) are limited. OBJECTIVE: To compare QOL of patients pursuing SBRT and EBRT versus AS. DESIGN, SETTING, AND PARTICIPANTS: A population-based cohort of 680 men with newly diagnosed localized prostate cancer was prospectively enrolled from 2011 to 2013. INTERVENTION: SBRT, EBRT without androgen deprivation therapy, or AS. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: QOL was prospectively assessed before treatment (baseline), and at 3, 12, and 24mo after treatment using the validated Prostate Cancer Symptom Indices, which contain four domains: sexual dysfunction, urinary obstruction/irritation, urinary incontinence, and bowel problems. Propensity weighting via logistic regression models was used to balance baseline characteristics, and the mean QOL scores of EBRT and SBRT patients were compared against AS patients as the control group. RESULTS AND LIMITATIONS: Compared with AS patients, EBRT patients had worse urinary obstructive/irritative symptoms and sexual dysfunction at 3mo, and worse bowel symptoms at 3 and 24mo. SBRT patients had similar scores as AS patients in all domains and across all time points; however, due to small sample size, worse sexual function and urinary incontinence in SBRT patients cannot be ruled out. Further research is needed to assess long-term outcomes. CONCLUSIONS: In a nonrandomized cohort of men with localized prostate cancer, SBRT appeared to result in favorable QOL results through 2yr of follow-up, but worse sexual function and urinary incontinence compared with AS cannot be ruled out completely. Larger studies with longer follow-up are needed to confirm these findings. PATIENT SUMMARY: Stereotactic body radiotherapy (SBRT) and active surveillance appear to have similar quality of life outcomes through 2yr, although worse sexual function and urinary incontinence from SBRT cannot be ruled out completely.

Myeloid Slc2a1-Deficient Murine Model Revealed Macrophage Activation and Metabolic Phenotype Are Fueled by GLUT1.

Macrophages (MΦs) are heterogeneous and metabolically flexible, with metabolism strongly affecting immune activation. A classic response to proinflammatory activation is increased flux through glycolysis with a downregulation of oxidative metabolism, whereas alternative activation is primarily oxidative, which begs the question of whether targeting glucose metabolism is a viable approach to control MΦ activation. We created a murine model of myeloid-specific glucose transporter GLUT1 (Slc2a1) deletion. Bone marrow-derived MΦs (BMDM) from Slc2a1M-/- mice failed to uptake glucose and demonstrated reduced glycolysis and pentose phosphate pathway activity. Activated BMDMs displayed elevated metabolism of oleate and glutamine, yet maximal respiratory capacity was blunted in MΦ lacking GLUT1, demonstrating an incomplete metabolic reprogramming. Slc2a1M-/- BMDMs displayed a mixed inflammatory phenotype with reductions of the classically activated pro- and anti-inflammatory markers, yet less oxidative stress. Slc2a1M-/- BMDMs had reduced proinflammatory metabolites, whereas metabolites indicative of alternative activation-such as ornithine and polyamines-were greatly elevated in the absence of GLUT1. Adipose tissue MΦs of lean Slc2a1M-/- mice had increased alternative M2-like activation marker mannose receptor CD206, yet lack of GLUT1 was not a critical mediator in the development of obesity-associated metabolic dysregulation. However, Ldlr-/- mice lacking myeloid GLUT1 developed unstable atherosclerotic lesions. Defective phagocytic capacity in Slc2a1M-/- BMDMs may have contributed to unstable atheroma formation. Together, our findings suggest that although lack of GLUT1 blunted glycolysis and the pentose phosphate pathway, MΦ were metabolically flexible enough that inflammatory cytokine release was not dramatically regulated, yet phagocytic defects hindered MΦ function in chronic diseases.

Imaging glioma initiation in vivo through a polished and reinforced thin-skull cranial window.

Glioma is the one of the most lethal forms of human cancer. The most effective glioma therapy to date-surgery followed by radiation treatment-offers patients only modest benefits, as most patients do not survive more than five years following diagnosis due to glioma relapse (1,2). The discovery of cancer stem cells in human brain tumors holds promise for having an enormous impact on the development of novel therapeutic strategies for glioma (3). Cancer stem cells are defined by their ability both to self-renew and to differentiate, and are thought to be the only cells in a tumor that have the capacity to initiate new tumors (4). Glioma relapse following radiation therapy is thought to arise from resistance of glioma stem cells (GSCs) to therapy (5-10). In vivo, GSCs are shown to reside in a perivascular niche that is important for maintaining their stem cell-like characteristics (11-14). Central to the organization of the GSC niche are vascular endothelial cells (12). Existing evidence suggests that GSCs and their interaction with the vascular endothelial cells are important for tumor development, and identify GSCs and their interaction with endothelial cells as important therapeutic targets for glioma. The presence of GSCs is determined experimentally by their capability to initiate new tumors upon orthotopic transplantation (15). This is typically achieved by injecting a specific number of GBM cells isolated from human tumors into the brains of severely immuno-deficient mice, or of mouse GBM cells into the brains of congenic host mice. Assays for tumor growth are then performed following sufficient time to allow GSCs among the injected GBM cells to give rise to new tumors-typically several weeks or months. Hence, existing assays do not allow examination of the important pathological process of tumor initiation from single GSCs in vivo. Consequently, essential insights into the specific roles of GSCs and their interaction with the vascular endothelial cells in the early stages of tumor initiation are lacking. Such insights are critical for developing novel therapeutic strategies for glioma, and will have great implications for preventing glioma relapse in patients. Here we have adapted the PoRTS cranial window procedure (16)and in vivo two-photon microscopy to allow visualization of tumor initiation from injected GBM cells in the brain of a live mouse. Our technique will pave the way for future efforts to elucidate the key signaling mechanisms between GSCs and vascular endothelial cells during glioma initiation.