Canine presumed glial brain tumours treated with radiotherapy: Is there an inferior outcome in tumours contacting the subventricular zone?

Post-treatment outcome in canine glial tumours is described with a broad range of survival times between 2 and 28 months. After surgery or radiation therapy, the tumours may progress locally or spread within the central nervous system. It is unknown if tumour- or patient-specific factors influence prognosis. In humans, glioblastoma involving the subventricular zone has been found to recur distantly, with shortened time to progression and overall survival. We included 32 dogs irradiated for a presumptive primary glial brain tumour in this retrospective cohort study. Tumours were grouped relative to subventricular zone contact and overt ventricular invasion assessing pre-treatment magnetic resonance images. Median time to progression (TTP) for all cases was 534 days (95%CI, 310–758), with a significantly shorter TTP in dogs with lesions at the subventricular zone (median TTP, 260 vs. 687 days; p =.049). Tumours at the subventricular zone progressed more often (p =.001), and more likely as CNS-metastasis (52.9% vs. 13.3%, p =.028). Median overall survival (OS) was 489 days (95%CI, 147–831) and median tumour-specific survival 609 days (95%CI, 382–835). Involvement of the subventricular zone was significantly associated with a shorter tumour-specific survival (median, 306 vs. 719 days; p =.044). Glial tumours contacting the subventricular zone in dogs have a shorter tumour-specific survival and a higher rate of progression and CNS-metastasis. Despite local tumour control, metastasis must be considered and should prompt further treatment approaches

Cell line-specific efficacy of thermoradiotherapy in human and canine cancer cells in vitro

Objective Aims were to investigate sensitivity of various human and canine cancer cell lines to hyperthermia and the influence of particular treatment conditions, and to analyze the DNA-damage response and mode of cell death in cell line radiosensitized by hyperthermia. Additionally, we were interested in the involvement of HSP70 in radiosensitization. Methods Radiosensitization by hyperthermia was determined in a panel of human and canine cancer cell lines using clonogenic cell survival assay, as well as levels of heat shock proteins (HSPs) using immunoblotting. The influence of the hyperthermia-radiotherapy time gap, different temperatures and the order of treatments on clonogenicity of hyperthermia-sensitive A549 cells was investigated. Additionally, DNA damage and cell death were assessed by Comet assay and an apoptosis/necrosis assay. Further we induced transient knockdown in A549 cells to test HSP70’s involvement in radiosensitization. Results Out of eight cell lines tested, only two (A549 and Abrams) showed significant decrease in clonogenic cell survival when pre-treated with hyperthermia at 42˚C. Strong induction of HSP70 upon thermoradiotherapy (HT-RT) treatment was found in all cell lines. Transient knockdown of HSP70 in A549 cells did not result in decrease of clonogenic cell survival in response to HT-RT. Conclusion Tumor cell-type, temperature and order of treatment play an important role in radiosensitization by hyperthermia. However, hyperthermia has limited potency to radiosensitize canine cancer cells grown in a 2D cell culture setting presented here. DNA damage and apoptosis/necrosis did not increase upon combined treatment and cytosolic levels of HSP70 appear not to play critical role in the radiosensitization of A549 cells

Risk adaptive planning with biology-based constraints may lead to higher tumor control probability in tumors of the canine brain: A planning study

Background: Classical radiation protocols are guided by physical dose delivered homogeneously over the target. Protocols are chosen to keep normal tissue complication probability (NTCP) at an acceptable level. Organs at risk (OAR) adjacent to the target volume could lead to underdosage of the tumor and a decrease of tumor control probability (TCP). The intent of our study was to explore a biology-based dose escalation: by keeping NTCP for OAR constant, radiation dose was to be maximized, allowing to result in heterogeneous dose distributions. Methods: We used computed tomography datasets of 25 dogs with brain tumors, previously treated with 10x4 Gy (40 Gy to PTV D50). We generated 3 plans for each patient: A) original treatment plan with homogeneous dose distribution, B) heterogeneous dose distribution with strict adherence to the same NTCPs as in A), and C) heterogeneous dose distribution with adherence to NTCP <5%. For plan comparison, TCPs and TCP equivalent doses (homogenous target dose which results in the same TCP) were calculated. To enable the use of the generalized equivalent uniform dose (gEUD) metric of the tumor target in plan optimization, the calculated TCP values were used to obtain the volume effect parameter a. Results: As intended, NTCPs for all OARs did not differ from plan A) to B). In plan C), however, NTCPs were significantly higher for brain (mean 2.5% (SD±1.9, 95%CI: 1.7,3.3), p<0.001), optic chiasm (mean 2.0% (SD±2.2, 95%CI: 1.0,2.8), p=0.010) compared to plan A), but no significant increase was found for the brainstem. For 24 of 25 of the evaluated patients, the heterogenous plans B) and C) led to an increase in target dose and projected increase in TCP compared to the homogenous plan A). Furthermore, the distribution of the projected individual TCP values as a function of the dose was found to be in good agreement with the population TCP model. Conclusion: Our study is a first step towards risk-adaptive radiation dose optimization. This strategy utilizes a biologic objective function based on TCP and NTCP instead of an objective function based on physical dose constraints. Keywords: Biologic objective function; Biology-based; Brain tumor; Dog; IMRT; Intensity-modulated radiation therapy; NTCP; Radiation therapy; Risk-adaptive optimization; TCP

Temozolomide is additive with cytotoxic effect of irradiation in canine glioma cell lines

Background: Similar to human glioblastoma patients, glial tumours in dogs have high treatment resistance and a guarded prognosis. In human medicine, the addition of temozolomide to radiotherapy leads to a favourable outcome in vivo as well as a higher antiproliferative effect on tumour cells in vitro. Objectives: The aim of the study was to determine the radio- and temozolomide-sensitivity of three canine glial tumour cell lines and to investigate a potential additive cytotoxic effect in combined treatment. Additionally, we wanted to detect the level of MGMT promoter methylation in these cell lines and to investigate a potential association between MGMT promoter methylation and treatment resistance. Methods: Cells were treated with various concentrations of temozolomide and/or irradiated with 4 and 8&nbsp;Gy. Radiosensitization by temozolomide was evaluated using proliferation assay and clonogenic assay, and MGMT DNA methylation was investigated using bisulfite next-generation sequencing. Results: In all tested canine cell lines, clonogenicity was inhibited significantly in combined treatment compared to radiation alone. All canine glial cell lines tested in this study were found to have high methylation levels of MGMT promoter. Conclusions: Hence, an additive effect of combined treatment in MGMT negative canine glial tumour cell lines in vitro was detected. This motivates to further investigate the association between treatment resistance and MGMT, such as MGMT promoter methylation status

Triple combination of lomustine, temozolomide and irradiation reduces canine glioma cell survival in vitro

BackgroundCombined chemoradiation offers a promising therapeutic strategy for dogs with glioma. The alkylating agents temozolomide (TMZ) and lomustine (CCNU) penetrate the blood‐brain barrier, and doses for dogs are established. Whether such combinations are clinically advantageous remains to be explored together with tumour‐specific markers.ObjectiveTo investigate if triple combination of lomustine, temozolomide and irradiation reduces canine glioma cell survival in vitro.MethodsWe evaluated the sensitising effect of CCNU alone and in combination with TMZ‐irradiation in canine glioma J3T‐BG cells and long‐term drug‐exposed subclones by using clonogenic survival and proliferation assays. Bisulphite‐SEQ and Western Blot were used to investigate molecular alterations.ResultsTMZ (200 μM) or CCNU alone (5 μM) reduced the irradiated survival fraction (4 Gy) from 60% to 38% (p = 0.0074) and 26% (p = 0.0002), respectively. The double‐drug combination reduced the irradiated survival fraction (4 Gy) more potently to 12% (p < 0.0001).After long‐term drug exposure, both subclones show higher IC$_{50}$ values against CCNU and TMZ. For CCNU‐resistant cells, both, single‐drug CCNU (p = 0.0006) and TMZ (p = 0.0326) treatment combined with irradiation (4 Gy) remained effective. The double‐drug‐irradiation combination reduced the cell survival by 86% (p < 0.0001), compared to 92% in the parental (nonresistant) cell line. For TMZ‐resistant cells, only the double‐drug combination with irradiation (4 Gy) reduced the cell survival by 88% (p = 0.0057) while single‐drug treatment lost efficacy.Chemoresistant cell lines demonstrated higher P‐gp expression while MGMT‐methylation profile analysis showed a general high methylation level in the parental and long‐term treated cell lines.ConclusionsOur findings indicate that combining CCNU with TMZ‐irradiation significantly reduces canine glioma cell survival. Such a combination could overcome current challenges of therapeutic resistance to improve overall patient survival

IP modeling of the survivable hop constrained connected facility location problem

Abstract We consider a generalized version of the rooted connected facility location problem which occurs in planning of telecommunication networks with both survivability and hop-length constraints. Given a set of client nodes, a set of potential facility nodes including one predetermined root facility, a set of optional Steiner nodes, and the set of the potential connections among these nodes, that task is to decide which facilities to open, how to assign the clients to the open facilities, and how to interconnect the open facilities in such a way, that the resulting network contains at least λ edge-disjoint paths, each containing at most H edges, between the root and each open facility and that the total cost for opening facilities and installing connections is minimal. We study two IP models for this problem and present a branch-and-cut algorithm based on Benders decomposition for finding its solution. Finally, we report computational results

Cloud mask algorithm from the EarthCARE Multi-Spectral Imager: the M-CM products

The EarthCARE (Earth Clouds, Aerosols and Radiation Explorer) satellite mission will provide new insights into aerosol–cloud–radiation interactions by means of synergistic observations of the Earth's atmosphere from a collection of active and passive remote sensing instruments, flying on a single satellite platform. The Multi-Spectral Imager (MSI) will provide visible and infrared images in the cross-track direction with a 150 km swath and a pixel sampling at 500 m. The suite of MSI cloud algorithms will deliver cloud macro- and microphysical properties complementary to the vertical profiles measured from the Atmospheric Lidar (ATLID) and the Cloud Profiling Radar (CPR) instruments. This paper provides an overview of the MSI cloud mask algorithm (M-CM) being developed to derive the cloud flag, cloud phase and cloud type products, which are essential inputs to downstream EarthCARE algorithms providing cloud optical and physical properties (M-COP) and aerosol optical properties (M-AOT). The MSI cloud mask algorithm has been applied to simulated test data from the EarthCARE end-to-end simulator and satellite data from the Moderate Resolution Imaging Spectroradiometer (MODIS) as well as from the Spinning Enhanced Visible InfraRed Imager (SEVIRI). Verification of the MSI cloud mask algorithm to the simulated test data and the official cloud products from SEVIRI and MODIS demonstrates a good performance of the algorithm. Some discrepancies are found, however, for the detection of thin cirrus clouds over bright surfaces like desert or snow. This will be improved by tuning of the thresholds once real observations are available.</p

Nicotinamide Riboside Augments Human Macrophage Migration via SIRT3-Mediated Prostaglandin E2 Signaling.

(i) NR supplementation protocol (NCT02812238) and (ii) healthy volunteer blood were obtained from the NIH Clinical Center Blood Bank. We thank and acknowledge the assistance of Dan Yan and Natalia Dmitrieva from Manfred Boehm’s group (NHLBI) for the IncuCyte live-cell analysis. We also thank Yun-Wei A. Hsu for her support with the metabolomics analysis at the Northwest Metabolomics Research Center (NIH grant 1S10OD021562-01).Peer reviewe

The oncofetal RNA-binding protein IGF2BP1 is a druggable, post-transcriptional super-enhancer of E2F-driven gene expression in cancer

The IGF2 mRNA-binding protein 1 (IGF2BP1) is a non-catalytic post-transcriptional enhancer of tumor growth upregulated and associated with adverse prognosis in solid cancers. However, conserved effector pathway(s) and the feasibility of targeting IGF2BP1 in cancer remained elusive. We reveal that IGF2BP1 is a post-transcriptional enhancer of the E2F-driven hallmark in solid cancers. IGF2BP1 promotes G1/S cell cycle transition by stabilizing mRNAs encoding positive regulators of this checkpoint like E2F1. This IGF2BP1-driven shortening of the G1 cell cycle phase relies on 3′UTR-, miRNA- and m6A-dependent regulation and suggests enhancement of cell cycle progression by m6A-modifications across cancers. In addition to E2F transcription factors, IGF2BP1 also stabilizes E2F-driven transcripts directly indicating post-transcriptional 'super'-enhancer role of the protein in E2F-driven gene expression in cancer. The small molecule BTYNB disrupts this enhancer function by impairing IGF2BP1-RNA association. Consistently, BTYNB interferes with E2F-driven gene expression and tumor growth in experimental mouse tumor models