Functional temozolomide sensitivity testing of patient-specific glioblastoma stem cell cultures is predictive of clinical outcome

Serum-free culturing of patient-derived glioblastoma biopsies enrich for glioblastoma stem cells (GSCs) and is recognized as a disease-relevant model system in glioblastoma (GBM). We hypothesized that the temozolomide (TMZ) drug sensitivity of patient-derived GSC cultures correlates to clinical sensitivity patterns and has clinical predictive value in a cohort of GBM patients. To this aim, we established 51 individual GSC cultures from surgical biopsies from both treatment-naive primary and pretreated recurrent GBM patients. The cultures were evaluated for sensitivity to TMZ over a dosing range achievable in normal clinical practice. Drug efficacy was quantified by the drug sensitivity score. MGMT-methylation status was investigated by pyrosequencing. Correlative, contin-gency, and survival analyses were performed for associations between experimental and clinical data. We found a heterogeneous response to temozolomide in the GSC culture cohort. There were significant differences in the sensitivity to TMZ between the newly diagnosed and the TMZ-treated recurrent disease (pPeer reviewe

Drug sensitivity and resistance testing of brain tumor stem cells for individualized functional precision medicine

Glioblastoma (GBM) is the most common malignant brain tumor in adults. Despite treatment consisting of surgery, radiation and chemotherapy, survival is limited and usually do not extend beyond a year. A major challenge in the development of new treatments is the complex tumor heterogeneity between patients that may render an effective treatment for one patient and ineffective for another. The aims of the thesis were to functionally profile glioblastoma stem cells (GSCs) in terms of drug sensitivity, and in turn develop new treatment strategies targeting GSCs in individual patients. This was undertaken using patient-specific cell cultures derived from surgical biopsies and automated high-throughput technology for drug sensitivity and resistance testing (DSRT) and drug sensitivity scoring of over 460 anticancer drugs. We found an extensive intertumoral heterogeneity in the drug sensitivity patterns between the individual GSC cultures. This was observed in overall sensitivity to the drug collection, in sensitivity to different drug classes and to single drugs. The results grouped GBMs into functional taxonomies based on drug sensitivity patterns and could also identify effective drugs for individual patients. The preclinical workup of culture establishment, expansion of GSCs, DSRT, and data analysis was feasible within a turnaround time to allow clinical translation of individualized treatment. A combination treatment consisting of nine drugs approved for non-oncological indications were also tested for efficacy in the individual GSCs, demonstrating an effect in around half of the tested cultures. Overall, this work describes an extensive tumoral heterogeneity in drug sensitivity patterns in GBM and demonstrate how automated DSRT of patient-derived GSCs can identify treatment options for individual patients. The thesis forms the basis for a clinical trial targeting autologous GSCs in GBM using the DSRT-platform and for extension of methods to brain cancers in children

Systemisk inflammasjon etter traume: Alarminer som aktivatorer av immunresponsen - med fokus på HMGB1.

Objectives: Systemic inflammatory response syndrome (SIRS) is commonly seen after sterile traumatic injury and may lead to multiple organ failure and death. Endogenous molecules termed alarmins are released following cellular stress or injury and activate the response. This literature review will discuss the mechanisms in immune system activation after trauma and compare to similar mechanisms in sepsis, with special focus on High mobility group box 1 (HMGB1). Possible future treatment options will also be briefly discussed. Methods: The review is based on (1) papers identified from search in PubMed, (2) papers received from my supervisor of the review, and (3) papers identified from citation lists from the papers after (1) and (2). Results: Activation and maintenance of the immune response after trauma and in sepsis involves the same receptors and signalling pathways, but different initial activators. Several endogenous molecules have shown alarmin characteristics both in vitro and in vivo, and preclinical studies with blockade of specific alarmins have shown promising results in reducing morbidity and mortality. Conclusion: Our understanding of mechanisms in the immune activation after trauma is insufficient, but improving. Identification of alarmins and their role in post-traumatic SIRS opens possibilities for future immune modulation also after traumatic injury, hopefully reducing the extent of inflammation, multiple organ failure, and death

The efficacy of a coordinated pharmacological blockade in glioblastoma stem cells with nine repurposed drugs using the CUSP9 strategy

Purpose Constructed from a theoretical framework, the coordinated undermining of survival paths in glioblastoma (GBM) is a combination of nine drugs approved for non-oncological indications (CUSP9; aprepitant, auranofin, captopril, celecoxib, disulfiram, itraconazole, minocycline, quetiapine, and sertraline) combined with temozolomide (TMZ). The availability of these drugs outside of specialized treatment centers has led patients to embark on combination treatments without systematic follow-up. However, no experimental data on efficacy using the CUSP9 strategy in GBM have been reported. Methods Using patient-derived glioblastoma stem cell (GSC) cultures from 15 GBM patients, we described stem cell properties of individual cultures, determined the dose–response relationships of the drugs in the CUSP9, and assessed the efficacy the CUSP9 combination with TMZ in concentrations clinically achievable. The efficacy was evaluated by cell viability, cytotoxicity, and sphere-forming assays in both primary and recurrent GSC cultures. Results We found that CUSP9 with TMZ induced a combination effect compared to the drugs individually (p < 0.0001). Evaluated by cell viability and cytotoxicity, 50% of the GSC cultures displayed a high sensitivity to the drug combination. In clinical plasma concentrations, the effect of the CUSP9 with TMZ was superior to TMZ monotherapy (p < 0.001). The Wnt-signaling pathway has been shown important in GSC, and CUSP9 significantly reduces Wnt-activity. Conclusions Adding experimental data to the theoretical rationale of CUSP9, our results demonstrate that the CUSP9 treatment strategy can induce a combination effect in both treatment-naïve and pretreated GSC cultures; however, predicting response in individual cultures will require further profiling of GSCs

HMGB1 concentration measurements in trauma patients: assessment of pre-analytical conditions and sample material

Background HMGB1 is a mediator of systemic inflammation in sepsis and trauma, and a promising biomarker in many diseases. There is currently no standard operating procedure for pre-analytical handling of HMGB1 samples, despite that pre-analytical conditions account for a substantial part of the overall error rate in laboratory testing. We hypothesized that the considerable variations in reported HMGB1 concentrations and kinetics in trauma patients could be partly explained by differences in pre-analytical conditions and choice of sample material. Methods Trauma patients (n = 21) admitted to a Norwegian Level I trauma center were prospectively included. Blood was drawn in K2EDTA coated tubes and serum tubes. The effects of delayed centrifugation were evaluated in samples stored at room temperature for 15 min, 3, 6, 12, and 24 h respectively. Plasma samples subjected to long-term storage in − 80 °C and to repeated freeze/thaw cycles were compared with previously analyzed samples. HMGB1 concentrations in simultaneously acquired arterial and venous samples were also compared. HMGB1 was assessed by standard ELISA technique, additionally we investigated the suitability of western blot in both serum and plasma samples. Results Arterial HMGB1 concentrations were consistently lower than venous concentrations in simultaneously obtained samples (arterial = 0.60 x venous; 95% CI 0.30–0.90). Concentrations in plasma and serum showed a strong linear correlation, however wide limits of agreement. Storage of blood samples at room temperature prior to centrifugation resulted in an exponential increase in plasma concentrations after ≈6 h. HMGB1 concentrations were fairly stable in centrifuged plasma samples subjected to long-term storage and freeze/thaw cycles. We were not able to detect HMGB1 in either serum or plasma from our trauma patients using western blotting. Conclusions Arterial and venous HMGB1 concentrations cannot be directly compared, and concentration values in plasma and serum must be compared with caution due to wide limits of agreement. Although HMGB1 levels in clinical samples from trauma patients are fairly stable, strict adherence to a pre-analytical protocol is advisable in order to protect sample integrity. Surprisingly, we were unable to detect HMGB1 utilizing standard western blot analysis

Real-world validity of randomized controlled phase III trials in newly diagnosed glioblastoma: to whom do the results of the trials apply?

Background The survival rates in population-based series of glioblastoma (GBM) differ substantially from those reported in clinical trials. This discrepancy may be attributed to that patients recruited to trials tend to be younger with better performance status. However, the proportion and characteristics of the patients in a population considered either eligible or ineligible for trials is unknown. The generalizability of trial results is therefore also uncertain. Methods Using the Cancer Registry of Norway and the Brain Tumor Database at Oslo University Hospital, we tracked all patients within a well-defined geographical area with newly diagnosed GBM during the years 2012–2017. Based on data from these registries and the medical records, the patients were evaluated for trial eligibility according to criteria employed in recent phase III trials for GBM. Results We identified 512 patients. The median survival was 11.7 months. When we selected a potential trial population at the start of concurrent chemoradiotherapy (radiotherapy [RT]/ temozolomide [TMZ]) by the parameters age (18–70 y), passed surgery for a supratentorial GBM, Eastern Cooperative Oncology Group (ECOG) ≤2, normal hematologic, hepatic and renal function, and lack of severe comorbidity, 57% of the patients were excluded. Further filtering the patients who progressed during RT/TMZ and never completed RT/TMZ resulted in exclusion of 59% and 63% of the patients, respectively. The survival of patients potentially eligible for trials was significantly higher than of the patients not fulfilling trial eligibility criteria (P < .0001). Conclusions Patients considered eligible for phase III clinical trials represent a highly selected minority of patients in a real-world GBM population

Feasibility study of using high-throughput drug sensitivity testing to target recurrent glioblastoma stem cells for individualized treatment

BACKGROUND: Despite the well described heterogeneity in glioblastoma (GBM), treatment is standardized, and clinical trials investigate treatment effects at population level. Genomics-driven oncology for stratified treatments allow clinical decision making in only a small minority of screened patients. Addressing tumor heterogeneity, we aimed to establish a clinical translational protocol in recurrent GBM (recGBM) utilizing autologous glioblastoma stem cell (GSC) cultures and automated high-throughput drug sensitivity and resistance testing (DSRT) for individualized treatment within the time available for clinical application. RESULTS: From ten patients undergoing surgery for recGBM, we established individual cell cultures and characterized the GSCs by functional assays. 7/10 GSC cultures could be serially expanded. The individual GSCs displayed intertumoral differences in their proliferative capacity, expression of stem cell markers and variation in their in vitro and in vivo morphology. We defined a time frame of 10 weeks from surgery to complete the entire pre-clinical work-up; establish individualized GSC cultures, evaluate drug sensitivity patterns of 525 anticancer drugs, and identify options for individualized treatment. Within the time frame for clinical translation 5/7 cultures reached sufficient cell yield for complete drug screening. The DSRT revealed significant intertumoral heterogeneity to anticancer drugs (p Peer reviewe

Intertumoral heterogeneity in patient-specific drug sensitivities in treatment-naive glioblastoma

BackgroundA major barrier to effective treatment of glioblastoma (GBM) is the large intertumoral heterogeneity at the genetic and cellular level. In early phase clinical trials, patient heterogeneity in response to therapy is commonly observed; however, how tumor heterogeneity is reflected in individual drug sensitivities in the treatment-naive glioblastoma stem cells (GSC) is unclear.MethodsWe cultured 12 patient-derived primary GBMs as tumorspheres and validated tumor stem cell properties by functional assays. Using automated high-throughput screening (HTS), we evaluated sensitivity to 461 anticancer drugs in a collection covering most FDA-approved anticancer drugs and investigational compounds with a broad range of molecular targets. Statistical analyses were performed using one-way ANOVA and Spearman correlation.ResultsAlthough tumor stem cell properties were confirmed in GSC cultures, their in vitro and in vivo morphology and behavior displayed considerable tumor-to-tumor variability. Drug screening revealed significant differences in the sensitivity to anticancer drugs (pPeer reviewe

Phenotypic and Expressional Heterogeneity in the Invasive Glioma Cells

BACKGROUND: Tumor cell invasion is a hallmark of glioblastoma (GBM) and a major contributing factor for treatment failure, tumor recurrence, and the poor prognosis of GBM. Despite this, our understanding of the molecular machinery that drives invasion is limited. METHODS: Time-lapse imaging of patient-derived GBM cell invasion in a 3D collagen gel matrix, analysis of both the cellular invasive phenotype and single cell invasion pattern with microarray expression profiling. RESULTS: GBM invasion was maintained in a simplified 3D-milieue. Invasion was promoted by the presence of the tumorsphere graft. In the absence of this, the directed migration of cells subsided. The strength of the pro-invasive repulsive signaling was specific for a given patient-derived culture. In the highly invasive GBM cultures, the majority of cells had a neural progenitor-like phenotype, while the less invasive cultures had a higher diversity in cellular phenotypes. Microarray expression analysis of the non-invasive cells from the tumor core displayed a higher GFAP expression and a signature of genes containing VEGFA, hypoxia and chemo-repulsive signals. Cells of the invasive front expressed higher levels of CTGF, TNFRSF12A and genes involved in cell survival, migration and cell cycle pathways. A mesenchymal gene signature was associated with increased invasion. CONCLUSION: The GBM tumorsphere core promoted invasion, and the invasive front was dominated by a phenotypically defined cell population expressing genes regulating traits found in aggressive cancers. The detected cellular heterogeneity and transcriptional differences between the highly invasive and core cells identifies potential targets for manipulation of GBM invasion