Heidi Espedal

University of Bergen | UiB · Molecular Imaging Center, Department of Biomedicine

Anti-angiogenic therapy in glioblastoma (GBM) has unfortunately not led to the anticipated improvement in patient prognosis. We here describe how human GBM adapts to bevacizumab treatment at the metabolic level. By performing 13C6-glucose metabolic flux analysis, we show for the first time that the tumors undergo metabolic re-programming toward ana...

The key metabolic enzyme lactate dehydrogenase A (LDHA) is overexpressed in many cancers, and several preclinical studies have shown encouraging results of targeted inhibition. However, the mechanistic importance of LDHA in melanoma is largely unknown and hitherto unexplored in brain metastasis. We investigated the spatial, temporal, and functional...

Polymer gel is frequently used for conformance control in fractured reservoirs, where it is injected to reside in fractures or high-permeability streaks to reduce conductivity. With successful polymer-gel conformance control in place, increased pressure gradients across matrix blocks may be achieved during chase floods, diverting water, gas, or enh...

Recent results from 2 double-blind, placebo-controlled phase III trials (RTOG 0825) and (AVAglio) for first-line treatment of glioblastoma patients with the VEGF antibody bevacizumab, showed similar results, related to overall and progression-free survival. The RTOG 0825 trial indicated, opposed to the AVAglio trial, that patients treated with beva...

In situ imaging by combined positron emission tomography (PET) – computed tomography (CT) provides unique insight into porous media flow: by combining information about structure (visible by CT) with direct quantification of fluid flow paths (visible by PET).

Positron emission tomography (PET) is routinely used for medical imaging; a current surge in published geoscientific research utilizing this modality also infer increasing interest for in-situ PET imaging in core analysis. Excellent signal to noise ratio coupled with high temporal and spatial resolution suggest that PET might become the new method-...

Objectives Patient-derived cancer organoids have quickly developed as valuable tools for drug testing as they better represent the genetic background of the patient cohort. We recently published a protocol for establishing EC organoids from all types and grades of EC (Berg et al, Nat Comms Med 2021). We here present data from a prospectively collec...

Lactate is a central metabolite in brain physiology but also contributes to tumor development. Glioblastoma (GB) is the most common and malignant primary brain tumor in adults, recognized by angiogenic and invasive growth, in addition to its altered metabolism. We show herein that lactate fuels GB anaplerosis by replenishing the tricarboxylic acid...

Introduction/Background Using clinically relevant imaging modalities in relevant animal models is crucial for strengthening the translational value of preclinical discoveries in endometrial cancer (EC). Imaging by ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) is commonly used in diagnostic work-up in EC. ¹...

Brain metastasis (BM) is a major cause of cancer patient morbidity. Clinical magnetic resonance imaging (MRI) and positron emission tomography (PET) represent important resources to assess tumor progression and treatment responses.In preclinical research, anatomical MRI and to some extent functional MRI have frequently been used to assess tumor pro...

Background Pelvic magnetic resonance imaging (MRI) and whole-body positron emission tomography-computed tomography (PET-CT) play an important role at primary diagnostic work-up and in detecting recurrent disease in endometrial cancer (EC) patients, however the preclinical use of these imaging methods is currently limited. We demonstrate the feasibi...

[This corrects the article DOI: 10.1038/s43856-021-00019-x.].

Background A major hurdle in translational endometrial cancer (EC) research is the lack of robust preclinical models that capture both inter- and intra-tumor heterogeneity. This has hampered the development of new treatment strategies for people with EC. Methods EC organoids were derived from resected patient tumor tissue and expanded in a chemica...

Lactate is a central metabolite in brain physiology, involved in the astrocyte-neuron lactate shuttle, but also contributes to tumor development. Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults, recognized by angiogenic and invasive growth, in addition to its altered metabolism. By adapting their glycolytic or oxid...

Background: Pelvic magnetic resonance imaging (MRI) and whole-body positron emission tomography-computed tomography (PET-CT) play an important role at primary diagnostic work-up and in detecting recurrent disease in endometrial cancer (EC) patients, however the preclinical use of these imaging methods is currently limited. We demonstrate the feasib...

Nitroreductases (NTR) are a family of bacterial enzymes used in gene directed enzyme prodrug therapy (GDEPT) that selectively activate prodrugs containing aromatic nitro groups to exert cytotoxic effects following gene transduction in tumours. The clinical development of NTR-based GDEPT has, in part, been hampered by the lack of translational imagi...

Adipose-derived stem cells (ASC) have been used as an alternative to bone marrow mesenchymal stem cells (BMSC) for bone tissue engineering. However, the efficacy of ASC in bone regeneration in comparison with BMSC remains debatable, since inconsistent results have been reported. Comparing ASC with BMSC obtained from different individuals might cont...

Blood levels of cardiac troponins (cTn) and myoglobin are analysed when myocardial infarction (MI) is suspected. Here we describe a novel clearance mechanism for muscle proteins by muscle cells. The complete plasma clearance profile of cTn and myoglobin was followed in rats after intravenous or intermuscular injections and analysed by PET and fluor...

Introduction: Comprehensive profiling of tumors using omics technologies has improved our understanding of the molecular landscape of endometrial cancer (EC), building the foundation for precision medicine. However, targeted therapies that show promise in preclinical research are failing clinical trials, which is partly explained by the lack of mod...

Imaging of clinically relevant preclinical animal models is critical to the development of personalized therapeutic strategies for endometrial carcinoma. Although orthotopic patient-derived xenografts (PDXs) reflecting heterogeneous molecular subtypes are considered the most relevant preclinical models, their use in therapeutic development is limit...

Brain metastasis is a major cause of mortality in melanoma patients. The blood-brain barrier (BBB) prevents most anti-tumor compounds from entering the brain, which significantly limits their use in the treatment of brain metastasis. One strategy in the development of new treatments is to assess the anti-tumor potential of drugs currently used in t...

Endometrial cancer is the most common gynecologic malignancy in industrialized countries. Most patients are cured by surgery; however, about 15% of the patients develop recurrence with limited treatment options. Patient-derived tumor xenograft (PDX) mouse models represent useful tools for preclinical evaluation of new therapies and biomarker identi...

BACKGROUND Glioblastomas are among the most malignant primary brain tumors. GBMs are highly angiogenic, exhibit invasive growth, and elevated glycolysis. Under glycolytic conditions, glucose from the blood is metabolized in astrocytes into lactate by LDHA, and exported by MCT4 into the extracellular compartment, inducing a concomitant acidification...

Patients with melanoma have a high risk of developing brain metastasis, which is associated with a dismal prognosis. During early stages of metastasis development, the blood-brain barrier (BBB) is likely intact, which inhibits sufficient drug delivery into the metastatic lesions. We investigated the ability of the peptide, K16ApoE, to permeabilize...

BACKGROUND: Melanoma patients have a high risk of developing brain metastases, which is associated with a poor prognosis. The blood-brain barrier (BBB) inhibits sufficient drug delivery into metastatic lesions. We investigated the ability of a synthetic peptide (K16ApoE) to permeabilize the BBB for more effective drug treatment. METHODS: DCE-MRI wa...

Background: Natural killer (NK) cells are potential effectors in anti-cancer immunotherapy; however only a subset potently kills cancer cells. Here, we examined whether pretreatment of glioblastoma (GBM) with the proteasome inhibitor, bortezomib (BTZ), might sensitize tumour cells to NK cell lysis by inducing stress antigens recognized by NK-activa...

Individuals with brain metastasis usually await a poor prognosis. Even with the ongoing development of novel targeted therapies, a major impediment in the treatment of brain metastasis is delivering of drugs across the blood-brain/tumor barrier. Different strategies to accomplish temporary opening of the heterogenous blood-brain barrier have been d...

Patients with brain metastases usually have a poor prognosis. Regardless of the constant progress in novel drug establishments, a crucial obstacle is the delivery of drugs across the blood brain barrier (BBB) and into the metastatic neoplasms. Different study designs to achieve temporary BBB opening have previously been studied. Here, we describe a...

Introduction: Patients with brain metastases await a dismal prognosis. Regardless of the continuous progress in drug development, a major problem is the delivery of drugs across the blood brain barrier (BBB) and into the metastatic neoplasms. The BBB excludes almost all compounds, in particular highly charged, hydrophilic or large compounds, and mo...

Neo-angiogenesis represents an important factor for the delivery of oxygen and nutrients to a growing tumour, and is considered to be one of the main pathodiagnostic features of glioblastomas (GBM). Anti-angiogenic therapy by vascular endothelial growth factor (VEGF) blocking agents has been shown to lead to morphological vascular normalisation res...

Individuals with metastatic disease within the brain usually await a poor prognosis. Regardless of the ongoing development of novel drugs, a significant challenge is the delivery of drugs across the blood brain barrier (BBB) and into the metastatic neoplasms. The BBB excludes almost all therapeutic compounds, as highly charged, hydrophilic or large...

Melanoma is a cancer that has become increasingly frequent over the last decades in the western world. Initial treatment for primary and locoregional melanoma is surgery. In metastatic disease, systematic treatment and recently immunotherapy has been the mainstay. At this stage however, the prognostic outlook is still bleak. Thus, new treatments ar...

Polymer gel is frequently used for conformance control in fractured reservoirs, where it is injected to reside in fractures or high-permeability streaks to reduce conductivity. With successful polymer gel conformance control in place, increased pressure gradients across matrix blocks may be achieved during chasefloods, diverting water, gas or EOR c...

The cancer stem cell model suggests that glioblastomas contain a subpopulation of stem-like tumor cells that reproduce themselves to sustain tumor growth. Targeting these cells thus represents a novel treatment strategy and therefore more specific markers that characterize glioblastoma stem cells need to be identified. In the present study, we perf...

OBJECTIVE: Glioblastomas (GBM) are highly angiogenic tumors and were initially perceived as good candidates for anti -angiogenic therapy. Bevacuzimab, a monoclonal anti-VEGF antibody, was approved by the FDA in 2009 as monotherapy for recurrent GBM, but recent phase III clinical studies revealed no overall survival benefit, yet with a small improve...

Transplantation of glioblastoma patient biopsy spheroids to the brain of T cell-compromised Rowett (nude) rats has been established as a representative animal model for human GBMs, with a tumor take rate close to 100%. In immunocompetent littermates however, primary human GBM tissue is invariably rejected. Here we show that after repeated passaging...

Intercellular communication between cancer cells, especially between cancer and stromal cells, plays an important role in disease progression. We examined the intercellular transfer of organelles and proteins in vitro and in vivo and the role of tunneling nanotubes (TNTs) in this process. TNTs are membrane bridges that facilitate intercellular tran...

There is an error in the fifth sentence of the Abstract. The correct sentence is: In contrast, rejection is associated with massive infiltration of the tumor bed by leukocytes, predominantly ED1+ microglia/macrophages, CD4+ T helper cells and CD8+ effector cells, and correlates with elevated serum levels of pro-inflammatory cytokines IL–1α, IL–18 a...

We have in two different xenograft model systems of human glioblastoma (GBM) that reflect the genotype and phenotype of human GBMs, assessed using 13C6-glucose metabolomic flux analysis, how the tumors adapt to anti-vascular therapy (bevacizumab treatment). A detailed LC-MS analyses of 13C-labeled metabolites show that the tumors adapt to therapy b...

Treatment of primary and recurrent glioblastoma with anti-angiogenic therapies, either alone or in combination with chemotherapy, fails to extend overall survival, despite the often reported improvements in progression free survival and patient health condition. To improve the efficacy of these therapies, a better understanding of the mechanisms of...