Characteristics and Outcomes of De Novo Genitourinary Malignancy in Solid Organ Transplant Recipients at the University of Minnesota.

BACKGROUND: Studies examining outcomes of genitourinary malignancy (GU) in the solid organ transplant (SOT) population predominantly focus on renal transplant recipients and consist of relatively small cohorts. We aimed to expand knowledge of the characteristics and outcomes of de novo GU malignancies in all patients with SOT at a large tertiary center. METHODS: The SOT database was queried for recipients with de novo bladder, renal cell, and prostate malignancy, and a retrospective chart review was performed. Descriptive statistics and Kaplan-Meier survival estimates were calculated. Cox proportional hazards regression was used for multivariate modeling of predictive factors in the development of GU malignancy. RESULTS: Solid organ transplant recipients with de novo bladder malignancy comprised 64.3% with high grade and 38.1% with advanced stage (≥T2) disease at initial diagnosis. Only 3.7% of patients with de novo renal cell carcinoma presented with metastatic disease, and 13.6% with localized disease developed recurrences. The most common stage in de novo prostate cancer patients was pT3 (52.2%). Kaplan-Meier estimates (95% CI) for 5-year overall (OS) and cancer-specific survival (CSS) were 44.12% (31.13-62.52) and 80.80% (68.85-94.81) for bladder, 78.90% (68.93-90.30) and 96.61% (92.10-100.00) for renal cell, and 81.18% (72.01-91.51) and 96.16% (90.95-100.00) for prostate cancer, respectively. Age at transplant and time from transplant to cancer diagnosis were predictive of de novo bladder cancer OS (P = .042 and .021, respectively). CONCLUSION: To our knowledge, this is the largest single-center cohort examined for GU malignancy after SOT. Bladder and renal cell cancer had worse OS but similar CSS as historical rates for nontransplant patients. De novo prostate cancer had similar CSS.

Predicting Glioblastoma Cellular Motility from In Vivo MRI with a Radiomics Based Regression Model.

Characterizing the motile properties of glioblastoma tumor cells could provide a useful way to predict the spread of tumors and to tailor the therapeutic approach. Radiomics has emerged as a diagnostic tool in the classification of tumor grade, stage, and prognosis. The purpose of this work is to examine the potential of radiomics to predict the motility of glioblastoma cells. Tissue specimens were obtained from 31 patients undergoing surgical resection of glioblastoma. Mean tumor cell motility was calculated from time-lapse videos of specimen cells. Manual segmentation was used to define the border of the enhancing tumor T1-weighted MR images, and 107 radiomics features were extracted from the normalized image volumes. Model parameter coefficients were estimated using the adaptive lasso technique validated with leave-one-out cross validation (LOOCV) and permutation tests. The R-squared value for the predictive model was 0.60 with p-values for each individual parameter estimate less than 0.0001. Permutation test models trained with scrambled motility failed to produce a model that out-performed the model trained on the true data. The results of this work suggest that it is possible for a quantitative MRI feature-based regression model to non-invasively predict the cellular motility of glioblastomas.

The effect of simulation training on resident proficiency in thoracolumbar pedicle screw placement using computer-assisted navigation.

OBJECTIVE: Residency work-hour restrictions necessitate efficient, reproducible training. Simulation training for spinal instrumentation placement shows significant benefit to learners' subjective and objective proficiency. Cadaveric laboratories are most effective but have high cost and low availability. The authors' goal was to create a low-cost, efficient, reproducible spinal instrumentation placement simulation curriculum for neurosurgery and orthopedic surgery residents using synthetic models and 3D computer-assisted navigation, assessing subjective and objective proficiency with placement of thoracolumbar pedicle screws. METHODS: Fifteen neurosurgery and orthopedic surgery residents participated in a standardized curriculum with lecture followed by two separate sessions of thoracolumbar pedicle screw placement in a synthetic spine model utilizing 3D computer-assisted navigation. Data were collected on premodule experience, time and accuracy of screw placement, and both subjective and objective ratings of proficiency. RESULTS: Fifteen of 15 residents demonstrated improvement in subjective (Physician Performance Diagnostic Inventory Scale [PPDIS]) and 14 in objective (Objective Structured Assessment of Technical Skills [OSATS]) measures of proficiency in navigated screw placement with utilization of this curriculum (p < 0.001 for both), regardless of the number of cases of previous experience using thoracolumbar spinal instrumentation. Fourteen of 15 residents demonstrated decreased time per screw placement from session 1 to session 2 (p = 0.006). There was no significant difference in pedicle screw accuracy between session 1 and session 2. CONCLUSIONS: A standardized curriculum using synthetic simulation training for navigated thoracolumbar pedicle screw placement results in significantly improved resident subjective and objective proficiency. Development of a nationwide competency curriculum using simulation training for spinal instrumentation placement should be considered for safe, efficient resident training.

Inflammation-induced iron transport and metabolism by brain microglia.

Microglia are immune cells of the central nervous system and are implicated in brain inflammation. However, how brain microglia modulate transport and metabolism of the essential metal iron in response to pro- and anti-inflammatory environmental cues is unclear. Here, we characterized uptake of transferrin (Tf)-bound iron (TBI) and non-Tf-bound iron (NTBI) by immortalized microglial (IMG) cells. We found that these cells preferentially take up NTBI in response to the proinflammatory stimulus lipopolysaccharide (LPS) or ß-amyloid (Aß). In contrast, the anti-inflammatory cytokine interleukin 4 (IL-4) promoted TBI uptake. Concordant with these functional data, levels of the Tf receptor (TfR) in IMG cells were up-regulated in response to IL-4, whereas divalent metal transporter-1 (DMT1) and ferritin levels increased in response to LPS or Aß. Similar changes in expression were confirmed in isolated primary adult mouse microglia treated with pro- or anti-inflammatory inducers. LPS-induced changes in IMG cell iron metabolism were accompanied by notable metabolic changes, including increased glycolysis and decreased oxidative respiration. Under these conditions, the extracellular acidification rate was increased, compatible with changes in the cellular microenvironment that would support the pH-dependent function of DMT1. Moreover, LPS increased heme oxygenase-1 (HO1) expression in IMG cells, and iron released because of HO1 activity increased the intracellular labile free-iron pool. Together, this evidence indicates that brain microglia preferentially acquire iron from Tf or from non-Tf sources, depending on their polarization state; that NTBI uptake is enhanced by the proinflammatory response; and that under these conditions microglia sequester both extra- and intracellular iron.

Immune and viral therapies for malignant primary brain tumors.

INTRODUCTION: Glioblastoma multiforme (GBM) is a primary brain tumor with great lethality. Current standard of care with surgery, radiation therapy, and chemotherapy are ineffective in curing this disease. Recent advancements in biological therapies show promise in treating brain tumors. Areas covered: This article provides a review of: the peripheral activation of antigen presenting cells such as dendritic cells to stimulate T cells to recognize and destroy tumor cells within the brain; the ex vivo expansion and transfer of dendritic cells, T cells, and engineered T cells expressing chimeric antigen receptors to target cells bearing specific tumor antigens as well as monoclonal antibodies as immune check point inhibitors. Gene therapy approaches have also been utilized to employ viral vectors in transducing cells to express cytokines for activating immune responses to brain tumors. Finally, the article reviews engineering of viruses for oncolytic targeting and destruction of malignant tumors within the brain. Expert opinion: The ultimate goal of immune and viral approaches for treating malignant brain tumors is to cure this disease. Preclinical and clinical studies utilizing these biological therapeutic approaches for treating brain tumors have the potential to augment the current standard of care to provide potential curative therapies.

Characterization of a novel adult murine immortalized microglial cell line and its activation by amyloid-beta.

BACKGROUND: Alzheimer's disease is associated with amyloid-beta (Aß)-induced microglia activation. This pro-inflammatory response promotes neuronal damage, and therapies are sought to limit microglial activation. Screening efforts to develop new pharmacological inhibitors require a robust in vitro cell system. Current models lack significant responses to Aß, and their use in examining age-related neurodegenerative diseases is questionable. For example, the commonly used BV-2 microglial line was derived from embryonic mononuclear cells and its activation by various stimuli is limited. To this end, we have established a new immortalized microglial (IMG) cell line from adult murine brain. The objective of this study was to characterize Aß-induced activation of IMG cells, and here, we demonstrate the ability of cannabinoids to significantly reduce this inflammatory response. METHODS: Microglial cells derived from adult murine brain were immortalized via infection with the v-raf/v-myc retrovirus under conditions that selectively promote microglia growth. The presence or absence of markers CD11b and F4/80 (microglial), NeuN (neuronal), and GFAP (astrocytic) was assessed by immunofluorescence microscopy and western blotting. Using IMG and BV-2 cells, levels of pro- and anti-inflammatory transcripts in response to extracellular stimuli were determined by quantitative PCR (qPCR). Phagocytosis of fluorescent beads and fluorescein isothiocyanate (FITC)-labeled Aß oligomers was assessed using flow cytometry and fluorescence microscopy. FITC-Aß uptake was quantified using a fluorescence plate reader. The ability of cannabinoids to mitigate Aß-induced expression of inducible nitric oxide synthase (iNOS) was evaluated. RESULTS: IMG cells express the microglial markers CD11b and F4/80 but not NeuN or GFAP. Relative to BV-2 cells, IMG cells increased iNOS (>200-fold) and Arg-1 (>100-fold) in response to pro- and anti-inflammatory stimuli. IMG cells phagocytose foreign particles and Aß oligomers, with the latter trafficked to phagolysosomes. Aß-induced activation of IMG cells was suppressed by delta-9-tetrahydrocannabinol and the CB2-selective agonist JWH-015 in a time- and concentration-dependent manner. CONCLUSIONS: IMG cells recapitulate key features of microglial cell activation. As an example of their potential pharmacological use, cannabinoids were shown to reduce activation of Aß-induced iNOS gene expression. IMG cells hold promising potential for drug screening, mechanistic studies, and functional investigations directed towards understanding how Aß interacts with microglia.

The small molecule ferristatin II induces hepatic hepcidin expression in vivo and in vitro.

Previous studies have shown that administration of ferristatin II to rats is associated with decreased serum iron, reduced transferrin saturation, and increased hepatic hepcidin expression. BMP and IL-6 signaling act via Smad and Stat3 transcription factors, respectively, to increase expression of hepcidin, the master regulator of iron metabolism. In this study, we aimed to explore the underlying mechanism of ferristatin II action on hepcidin production. We found that ferristatin II greatly increased hepcidin expression both in vivo and in vitro. In the rat liver, ferristatin II treatment decreased expression of Smad downstream targets Smad7 and Id1 and increased expression of Stat3 downstream targets α-2-macroglobulin, α-1-acid glycoprotein, and C-reactive peptide. Ferristatin II also increased Stat3 phosphorylation in the rat liver without affecting serum or hepatic IL-6 levels. It is unclear whether the Stat3 activation observed in vivo is a cause or a consequence to hepcidin induction. Reporter gene expression studies demonstrated that ferristatin II synergized with BMP6 and IL-6 to enhance hepcidin expression in vitro. However, this synergy was not due to activation of either Smad or Stat3 signaling, raising the possibility that ferristatin II may activate a novel pathway for hepcidin regulation.