Challenges and Prospects for Designer T and NK Cells in Glioblastoma Immunotherapy

Glioblastoma (GBM) is the most prevalent, aggressive primary brain tumour with a dismal prognosis. Treatment at diagnosis has limited efficacy and there is no standardised treatment at recurrence. New, personalised treatment options are under investigation, although challenges persist for heterogenous tumours such as GBM. Gene editing technologies are a game changer, enabling design of novel molecular-immunological treatments to be used in combination with chemoradiation, to achieve long lasting survival benefits for patients. Here, we review the literature on how cutting-edge molecular gene editing technologies can be applied to known and emerging tumour-associated antigens to enhance chimeric antigen receptor T and NK cell therapies for GBM. A tight balance of limiting neurotoxicity, avoiding tumour antigen loss and therapy resistance, while simultaneously promoting long-term persistence of the adoptively transferred cells must be maintained to significantly improve patient survival. We discuss the opportunities and challenges posed by the brain contexture to the administration of the treatments and achieving sustained clinical responses.publishedVersio

NK cells with KIR2DS2 immunogenotype have a functional activation advantage to efficiently kill glioblastoma and prolong animal survival

Glioblastomas (GBMs) are lethal brain cancers that are resistant to current therapies. We investigated the cytotoxicity of human allogeneic NK cells against patient-derived GBM in vitro and in vivo, as well as mechanisms mediating their efficacy. We demonstrate that KIR2DS2 immunogenotype NK cells were more potent killers, notwithstanding the absence of inhibitory killer Ig–like receptor (KIR)-HLA ligand mismatch. FACS-sorted and enriched KIR2DS2+ NK cell subpopulations retained significantly high levels of CD69 and CD16 when in contact with GBM cells at a 1:1 ratio and highly expressed CD107a and secreted more soluble CD137 and granzyme A. In contrast, KIR2DS2− immunogenotype donor NK cells were less cytotoxic against GBM and K562, and, similar to FACS-sorted or gated KIR2DS2− NK cells, significantly diminished CD16, CD107a, granzyme A, and CD69 when in contact with GBM cells. Furthermore, NK cell–mediated GBM killing in vitro depended upon the expression of ligands for the activating receptor NKG2D and was partially abrogated by Ab blockade. Treatment of GBM xenografts in NOD/SCID mice with NK cells from a KIR2DS2+ donor lacking inhibitory KIR-HLA ligand mismatch significantly prolonged the median survival to 163 d compared with vehicle controls (log-rank test, p = 0.0001), in contrast to 117.5 d (log-rank test, p = 0.0005) for NK cells with several inhibitory KIR-HLA ligand mismatches but lacking KIR2DS2 genotype. Significantly more CD56+CD16+ NK cells from a KIR2DS2+ donor survived in nontumor-bearing brains 3 wk after infusion compared with KIR2DS2− NK cells, independent of their proliferative capacity. In conclusion, KIR2DS2 identifies potent alloreactive NK cells against GBM that are mediated by commensurate, but dominant, activating signals.publishedVersio

Feasibility of deep learning-based tumor segmentation for target delineation and response assessment in grade-4 glioma using multi-parametric MRI

Background Tumor burden assessment is essential for radiation therapy (RT), treatment response evaluation, and clinical decision-making. However, manual tumor delineation remains laborious and challenging due to radiological complexity. The objective of this study was to investigate the feasibility of the HD-GLIO tool, an ensemble of pre-trained deep learning models based on the nnUNet-algorithm, for tumor segmentation, response prediction, and its potential for clinical deployment. Methods We analyzed the predicted contrast-enhanced (CE) and non-enhancing (NE) HD-GLIO output in 49 multi-parametric MRI examinations from 23 grade-4 glioma patients. The volumes were retrospectively compared to corresponding manual delineations by 2 independent operators, before prospectively testing the feasibility of clinical deployment of HD-GLIO-output to a RT setting. Results For CE, median Dice scores were 0.81 (95% CI 0.71–0.83) and 0.82 (95% CI 0.74–0.84) for operator-1 and operator-2, respectively. For NE, median Dice scores were 0.65 (95% CI 0.56–0,69) and 0.63 (95% CI 0.57–0.67), respectively. Comparing volume sizes, we found excellent intra-class correlation coefficients of 0.90 (P .01) for non-responders, and 0.80 (P = .05) for intermediate/mixed responders. Conclusions HD-GLIO was feasible for RT target delineation and MRI tumor volume assessment. CE/NE tumor-compartment growth correlation showed potential to predict clinical response to treatment.publishedVersio

A reproducible brain tumour model established from human glioblastoma biopsies

Background: Establishing clinically relevant animal models of glioblastoma multiforme (GBM) remains a challenge, and many commonly used cell line-based models do not recapitulate the invasive growth patterns of patient GBMs. Previously, we have reported the formation of highly invasive tumour xenografts in nude rats from human GBMs. However, implementing tumour models based on primary tissue requires that these models can be sufficiently standardised with consistently high take rates. Methods: In this work, we collected data on growth kinetics from a material of 29 biopsies xenografted in nude rats, and characterised this model with an emphasis on neuropathological and radiological features. Results: The tumour take rate for xenografted GBM biopsies were 96% and remained close to 100% at subsequent passages in vivo, whereas only one of four lower grade tumours engrafted. Average time from transplantation to the onset of symptoms was 125 days ± 11.5 SEM. Histologically, the primary xenografts recapitulated the invasive features of the parent tumours while endothelial cell proliferations and necrosis were mostly absent. After 4-5 in vivo passages, the tumours became more vascular with necrotic areas, but also appeared more circumscribed. MRI typically revealed changes related to tumour growth, several months prior to the onset of symptoms. Conclusions: In vivo passaging of patient GBM biopsies produced tumours representative of the patient tumours, with high take rates and a reproducible disease course. The model provides combinations of angiogenic and invasive phenotypes and represents a good alternative to in vitro propagated cell lines for dissecting mechanisms of brain tumour progression.publishedVersio

Gamma knife surgery as monotherapy with clinically relevant doses prolongs survival in a Human GBM Xenograft Model

Object. Gamma knife surgery (GKS) may be used for recurring glioblastomas (GBMs). However, patients have then usually undergone multimodal treatment, which makes it difficult to specifically validate GKS independent of established treatments. Thus, we developed an experimental brain tumor model to assess the efficacy and radiotoxicity associated with GKS. Methods. GBM xenografts were implanted intracerebrally in nude rats, and engraftment was confirmed with MRI. The rats were allocated to GKS, with margin doses of 12Gy or 18Gy, or to no treatment. Survival time was recorded, tumor sections were examined, and radiotoxicity was evaluated in a behavioral open field test. Results. In the first series, survival from the time of implantation was 96 days in treated rats and 72 days in controls ( < 0.001). In a second experiment, survival was 72 days in the treatment group versus 54 days in controls ( < 0.006). Polynuclear macrophages and fibrosis was seen in groups subjected to GKS. Untreated rats with GBM xenografts displayed less mobility than GKS-treated animals in the open field test 4 weeks after treatment ( = 0.04). Conclusion.GKS administered with clinically relevant doses prolongs survival in rats harboringGBMxenografts, and the associated toxicity is mild.publishedVersio

A reproducible brain tumour model established from human glioblastoma biopsies

<p>Abstract</p> <p>Background</p> <p>Establishing clinically relevant animal models of glioblastoma multiforme (GBM) remains a challenge, and many commonly used cell line-based models do not recapitulate the invasive growth patterns of patient GBMs. Previously, we have reported the formation of highly invasive tumour xenografts in nude rats from human GBMs. However, implementing tumour models based on primary tissue requires that these models can be sufficiently standardised with consistently high take rates.</p> <p>Methods</p> <p>In this work, we collected data on growth kinetics from a material of 29 biopsies xenografted in nude rats, and characterised this model with an emphasis on neuropathological and radiological features.</p> <p>Results</p> <p>The tumour take rate for xenografted GBM biopsies were 96% and remained close to 100% at subsequent passages <it>in vivo</it>, whereas only one of four lower grade tumours engrafted. Average time from transplantation to the onset of symptoms was 125 days ± 11.5 SEM. Histologically, the primary xenografts recapitulated the invasive features of the parent tumours while endothelial cell proliferations and necrosis were mostly absent. After 4-5 <it>in vivo </it>passages, the tumours became more vascular with necrotic areas, but also appeared more circumscribed. MRI typically revealed changes related to tumour growth, several months prior to the onset of symptoms.</p> <p>Conclusions</p> <p><it>In vivo </it>passaging of patient GBM biopsies produced tumours representative of the patient tumours, with high take rates and a reproducible disease course. The model provides combinations of angiogenic and invasive phenotypes and represents a good alternative to <it>in vitro </it>propagated cell lines for dissecting mechanisms of brain tumour progression.</p

Targeting the NG2/CSPG4 Proteoglycan Retards Tumour Growth and Angiogenesis in Preclinical Models of GBM and Melanoma

Aberrant expression of the progenitor marker Neuron-glia 2 (NG2/CSPG4) or melanoma proteoglycan on cancer cells and angiogenic vasculature is associated with an aggressive disease course in several malignancies including glioblastoma multiforme (GBM) and melanoma. Thus, we investigated the mechanism of NG2 mediated malignant progression and its potential as a therapeutic target in clinically relevant GBM and melanoma animal models. Xenografting NG2 overexpressing GBM cell lines resulted in increased growth rate, angiogenesis and vascular permeability compared to control, NG2 negative tumours. The effect of abrogating NG2 function was investigated after intracerebral delivery of lentivirally encoded shRNAs targeting NG2 in patient GBM xenografts as well as in established subcutaneous A375 melanoma tumours. NG2 knockdown reduced melanoma proliferation and increased apoptosis and necrosis. Targeting NG2 in two heterogeneous GBM xenografts significantly reduced tumour growth and oedema levels, angiogenesis and normalised vascular function. Vascular normalisation resulted in increased tumour invasion and decreased apoptosis and necrosis. We conclude that NG2 promotes tumour progression by multiple mechanisms and represents an amenable target for cancer molecular therapy

Expression of the progenitor marker NG2/CSPG4 predicts poor survival and resistance to ionising radiation in glioblastoma

Glioblastoma (GBM) is a highly aggressive brain tumour, where patients respond poorly to radiotherapy and exhibit dismal survival outcomes. The mechanisms of radioresistance are not completely understood. However, cancer cells with an immature stem-like phenotype are hypothesised to play a role in radioresistance. Since the progenitor marker neuron-glial-2 (NG2) has been shown to regulate several aspects of GBM progression in experimental systems, we hypothesised that its expression would influence the survival of GBM patients. Quantification of NG2 expression in 74 GBM biopsies from newly diagnosed and untreated patients revealed that 50% express high NG2 levels on tumour cells and associated vessels, being associated with significantly shorter survival. This effect was independent of age at diagnosis, treatment received and hypermethylation of the O6-methylguanine methyltransferase (MGMT) DNA repair gene promoter. NG2 was frequently co-expressed with nestin and vimentin but rarely with CD133 and the NG2 positive tumour cells harboured genetic aberrations typical for GBM. 2D proteomics of 11 randomly selected biopsies revealed upregulation of an antioxidant, peroxiredoxin-1 (PRDX-1), in the shortest surviving patients. Expression of PRDX-1 was associated with significantly reduced products of oxidative stress. Furthermore, NG2 expressing GBM cells showed resistance to ionising radiation (IR), rapidly recognised DNA damage and effectuated cell cycle checkpoint signalling. PRDX-1 knockdown transiently slowed tumour growth rates and sensitised them to IR in vivo. Our data establish NG2 as an important prognostic factor for GBM patient survival, by mediating resistance to radiotherapy through induction of ROS scavenging enzymes and preferential DNA damage signalling

Transnasjonal aktivisme mot tortur: Norske psykologer og psykiatere og traumebehandling av flyktninger

Denne oppgaven undersøker hvordan og hvorfor norske psykologer og psykiatere ble opptatt av traumebehandling av flyktninger. Gjennom 1970-tallet utviklet det seg fra spredte og personlig initiativ til å bli etablert et statlig Psykososialt team for flyktninger i 1986. I arbeidet med oppgaven har det pekt seg ut tre hovedtema. For det første hadde psykologene og psykiaterne et personlig initiativ og et solidaritetsengasjement. Dette engasjementet ble formet av personlige opplevelser og internasjonale hendelser. For det andre ble det et stort fokus på tortur på 1970-tallet. Dette fokuset ble særlig drevet av menneskerettighetsorganisasjoner som knyttet til seg helsepersonell for å dokumentere tortur og overgrep. I dette samarbeidet ble følgene av tortur tydeliggjort og det ble utviklet verktøy som ble viktige i traumebehandlingen. Til sist ble psykologene og psykiaterne på 1980-tallet del av et transnasjonalt nettverk som utvekslet kunnskap og erfaringer i internasjonale og regionale forum. Denne kunnskapsutvekslingen ble essensiell for utviklingen av et traumebehandlingstilbud i Norge

Challenges and Prospects for Designer T and NK Cells in Glioblastoma Immunotherapy

Glioblastoma (GBM) is the most prevalent, aggressive primary brain tumour with a dismal prognosis. Treatment at diagnosis has limited efficacy and there is no standardised treatment at recurrence. New, personalised treatment options are under investigation, although challenges persist for heterogenous tumours such as GBM. Gene editing technologies are a game changer, enabling design of novel molecular-immunological treatments to be used in combination with chemoradiation, to achieve long lasting survival benefits for patients. Here, we review the literature on how cutting-edge molecular gene editing technologies can be applied to known and emerging tumour-associated antigens to enhance chimeric antigen receptor T and NK cell therapies for GBM. A tight balance of limiting neurotoxicity, avoiding tumour antigen loss and therapy resistance, while simultaneously promoting long-term persistence of the adoptively transferred cells must be maintained to significantly improve patient survival. We discuss the opportunities and challenges posed by the brain contexture to the administration of the treatments and achieving sustained clinical responses