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result(s) for
"Siesjö, Peter"
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Convection-enhanced delivery of temozolomide and whole cell tumor immunizations in GL261 and KR158 experimental mouse gliomas
by
Kopecky, Jan
,
Enríquez Pérez, Julio
,
Siesjö, Peter
in
Analysis
,
Animals
,
Antineoplastic agents
2020
Background
Glioblastomas (GBM) are therapy-resistant tumors with a profoundly immunosuppressive tumor microenvironment. Chemotherapy has shown limited efficacy against GBM. Systemic delivery of chemotherapeutic drugs is hampered by the difficulty of achieving intratumoral levels as systemic toxicity is a dose-limiting factor. Although some of its effects might be mediated by immune reactivity, systemic chemotherapy can also inhibit induced or spontaneous antitumor immune reactivity. Convection-enhanced delivery of temozolomide (CED-TMZ) can tentatively increase intratumoral drug concentration while reducing systemic side effects. The objective of this study was to evaluate the therapeutic effect of intratumorally delivered temozolomide in combination with immunotherapy and whether such therapy can generate a cellular antitumor immune response.
Methods
Single bolus intratumoral injection and 3-day mini-osmotic pumps (Alzet®) were used to deliver intratumoral TMZ in C57BL6 mice bearing orthotopic gliomas. Immunotherapy consisted of subcutaneous injections of irradiated GL261 or KR158 glioma cells. Tumor size and intratumoral immune cell populations were analyzed by immunohistochemistry.
Results
Combined CED-TMZ and immunotherapy had a synergistic antitumor effect in the GL261 model, compared to CED-TMZ or immunotherapy as monotherapies. In the KR158 model, immunization cured a small proportion of the mice whereas addition of CED-TMZ did not have a synergistic effect. However, CED-TMZ as monotherapy prolonged the median survival. Moreover, TMZ bolus injection in the GL261 model induced neurotoxicity and lower cure rate than its equivalent dose delivered by CED. In addition, we found that T-cells were the predominant cells responsible for the TMZ antitumor effect in the GL261 model. Finally, CED-TMZ combined with immunotherapy significantly reduced tumor volume and increased the intratumoral influx of T-cells in both models.
Conclusions
We show that immunotherapy synergized with CED-TMZ in the GL261 model and cured animals in the KR158 model. Single bolus administration of TMZ was effective with a narrower therapeutic window than CED-TMZ. Combined CED-TMZ and immunotherapy led to an increase in the intratumoral influx of T-cells. These results form part of the basis for the translation of the therapy to patients with GBM but the dosing and timing of delivery will have to be explored in depth both experimentally and clinically.
Journal Article
Antisecretory factor in severe traumatic brain injury (AFISTBI): protocol for an exploratory randomized placebo-controlled trial
2025
Background
Despite recent advances in neuroimaging and neurocritical care, severe traumatic brain injury (TBI) is still a major cause of severe disability and mortality, with increasing incidence worldwide. Antisecretory factor (AF), commercially available as Salovum®, has been shown to lower intracranial pressure (ICP) in experimental models of, e.g., TBI and herpes encephalitis. The aim of this study is to assess the effect of antisecretory factors in adult patients with severe TBI on ICP and inflammatory mediators in extracellular fluid and plasma.
Methods/design
This is a single-center, randomized, placebo-controlled clinical phase 2 trial, investigating the clinical superiority of Salovum® given as a food supplement during 5 days to adults with severe TBI (Glasgow Coma Scale (GCS) < 9), admitted to the neurocritical intensive care unit (NICU) at Skane university hospital, Lund, Sweden. All patients with GCS < 9 and clinical indication for insertion of ICP-monitor and microdialysis catheter will be screened for inclusion and assigned to either the treatment group (
n
= 10) or placebo group (
n
= 10). In both groups, the primary outcome will be ICP (mean values and change from baseline during intervention), registered from high-frequency data monitoring for 5 days. Secondary outcomes will be inflammatory mediators in plasma and intracerebral microdialysis perfusate days 1, 3, and 5 during trial treatment.
Trial registration
ClinicalTrials.gov
NCT04117672
. Registered on September 17, 2017. Protocol version 6 from October 24, 2023.
Journal Article
Outcome in adult patients with severe TBI, using a management protocol allowing a cerebral perfusion pressure ≤ 60 mmHg – a retrospective study over 10 years
2025
Background
Current guidelines for the treatment of severe TBI recommend maintaining a cerebral perfusion pressure (CPP) at 60–70 mmHg. In our institution, as well as others, an alternative algorithm—originally named the Lund concept—has been used. This treatment algorithm employs metoprolol and clonidine to limit CPP, accepting levels below 60 mmHg, with the aim of reducing cerebral edema. Previous reports on this algorithm have shown promising outcome in severe TBI cohorts when compared with many contemporary practices; however, no population-based studies have been conducted to validate these findings.
Research Question:
What is the outcome in adult severe TBI using the Lund Concept algorithm in a population-based cohort and how are CPP levels lower than 60 mmHg tolerated?
Methods
The study included 135 evaluable adult patients out of 171 admitted with severe TBI over a ten-year period in the southern Swedish healthcare region. Baseline data, intracranial pressure (ICP), CPP, treatment duration, surgical interventions, and administered drugs were correlated to the Glasgow Outcome Scale Extended (GOSE).
Results
The 30-day and 6-month mortality rates were 16% and 20%, respectively. A favorable outcome (GOSE 5–8) was achieved in 48% of patients. Only increasing age was associated with inferior outcomes.
Conclusion
The use of a management protocol accepting lower CPP levels than those recommended in existing guidelines was generally well tolerated with outcome in line with comparable reports.
Journal Article
Intratumoral administration of the antisecretory peptide AF16 cures murine gliomas and modulates macrophage functions
2022
Glioblastoma has remained the deadliest primary brain tumor while its current therapy offers only modest survival prolongation. Immunotherapy has failed to record notable benefits in routine glioblastoma treatment. Conventionally, immunotherapy relies on T cells as tumor-killing agents; however, T cells are outnumbered by macrophages in glioblastoma microenvironment. In this study, we explore the effect of AF16, a peptide from the endogenous antisecretory factor protein, on the survival of glioma-bearing mice, the tumor size, and characteristics of the tumor microenvironment with specific focus on macrophages. We elucidate the effect of AF16 on the inflammation-related secretome of human and murine macrophages, as well as human glioblastoma cells. In our results, AF16 alone and in combination with temozolomide leads to cure in immunocompetent mice with orthotopic GL261 gliomas, as well as prolonged survival in immunocompromised mice. We recorded decreased tumor size and changes in infiltration of macrophages and T cells in the murine glioma microenvironment. Human and murine macrophages increased expression of proinflammatory markers in response to AF16 treatment and the same effect was seen in human primary glioblastoma cells. In summary, we present AF16 as an immunomodulatory factor stimulating pro-inflammatory macrophages with a potential to be implemented in glioblastoma treatment protocols.
Journal Article
Wnt/β-catenin pathway regulates MGMT gene expression in cancer and inhibition of Wnt signalling prevents chemoresistance
2015
The DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) is commonly overexpressed in cancers and is implicated in the development of chemoresistance. The use of drugs inhibiting MGMT has been hindered by their haematologic toxicity and inefficiency. As a different strategy to inhibit MGMT we investigated cellular regulators of MGMT expression in multiple cancers. Here we show a significant correlation between Wnt signalling and MGMT expression in cancers with different origin and confirm the findings by bioinformatic analysis and immunofluorescence. We demonstrate Wnt-dependent MGMT gene expression and cellular co-localization between active β-catenin and MGMT. Pharmacological or genetic inhibition of Wnt activity downregulates MGMT expression and restores chemosensitivity of DNA-alkylating drugs in mouse models. These findings have potential therapeutic implications for chemoresistant cancers, especially of brain tumours where the use of temozolomide is frequently used in treatment.
The high expression of the DNA repair enzyme O6-methylguanine DNA methyltransferase (MGMT) often confers resistance to chemotherapy in several cancers. In this study, the authors propose the inhibition of the Wnt signalling pathway as an alternative strategy to modulate MGMT expression and sensitize tumours to chemotherapy.
Journal Article
Detection of human cytomegalovirus in medulloblastomas reveals a potential therapeutic target
2011
Medulloblastomas are the most common malignant brain tumors in children. They express high levels of COX-2 and produce PGE2, which stimulates tumor cell proliferation. Human cytomegalovirus (HCMV) is prevalent in the human population and encodes proteins that provide immune evasion strategies and promote oncogenic transformation and oncomodulation. In particular, HCMV induces COX-2 expression; STAT3 phosphorylation; production of PGE2, vascular endothelial growth factor, and IL-6; and tumor formation in vivo. Here, we show that a large proportion of primary medulloblastomas and medulloblastoma cell lines are infected with HCMV and that COX-2 expression, along with PGE2 levels, in tumors is directly modulated by the virus. Our analysis indicated that both HCMV immediate-early proteins and late proteins are expressed in the majority of primary medulloblastomas. Remarkably, all of the human medulloblastoma cell lines that we analyzed contained HCMV DNA and RNA and expressed HCMV proteins at various levels in vitro. When engrafted into immunocompromised mice, human medulloblastoma cells induced expression of HCMV proteins. HCMV and COX-2 expression correlated in primary tumors, cell lines, and medulloblastoma xenografts. The antiviral drug valganciclovir and the specific COX-2 inhibitor celecoxib prevented HCMV replication in vitro and inhibited PGE2 production and reduced medulloblastoma tumor cell growth both in vitro and in vivo. Ganciclovir did not affect the growth of HCMV-negative tumor cell lines. These findings imply an important role for HCMV in medulloblastoma and suggest HCMV as a novel therapeutic target for this tumor.
Journal Article
Antisecretory factor as add-on treatment for newly diagnosed glioblastoma, IDH wildtype: study protocol for a randomized double-blind placebo-controlled trial
by
Siesjö, Peter
,
Kinhult, Sara
,
Darabi, Anna
in
Adults
,
Angiogenesis
,
Antineoplastic Agents, Alkylating - administration & dosage
2025
Background
Glioblastoma, IDH wildtype is the most common primary malignant brain tumor in adults. Despite best available treatment, prognosis remains poor. Current standard therapy consists of surgical tumor removal followed by radiotherapy and chemotherapy with the alkylating agent temozolomide. Antisecretory factor (AF), an endogenous protein, may potentiate the effect of temozolomide and alleviate cerebral edema. Salovum® is an egg-yolk powder enriched for AF and is classified as a medical food in the European Union. Salovum® has shown preliminary clinical effect on glioblastoma in a recent pilot study. Here, we aim to assess if add-on Salovum® to temozolomide therapy can improve outcomes in patients with newly diagnosed glioblastoma.
Methods
This is a multi-center, double-blinded, randomized, placebo-controlled phase II-III clinical trial to investigate superiority of Salovum® over placebo as add-on treatment for glioblastoma during concomitant and adjuvant temozolomide therapy. Patients with newly diagnosed glioblastoma that are planned for temozolomide treatment are screened for eligibility and randomized to receive Salovum® (
n
= 150) or placebo (
n
= 150). An interim analysis will be performed after 80 included patients to guide whether to continue or terminate. Primary endpoint is 12-month overall survival. Secondary outcome is 24-month overall survival.
Discussion
This study will likely produce high-grade evidence to support or reject Salovum® as add-on treatment for glioblastoma.
Trial registration
ClinicalTrials.gov
NCT05669820
. Registered on January 3, 2023.
Journal Article
Effect of antisecretory factor, given as a food supplement to adult patients with severe traumatic brain injury (SASAT): protocol for an exploratory randomized double blind placebo-controlled trial
2022
Background
Traumatic brain injury (TBI) constitutes a global epidemic. Overall outcome is poor, with mortality ranging from 10 to 70% and significant long-term morbidity. Several experimental reports have claimed effect on traumatic edema, but no clinical trials have shown effect on edema or outcome. Antisecretory factor, an endogenous protein, is commercially available as Salovum®, which is classified as a medical food by the European Union and has shown effect in experimental trauma models and feasibility with signs of effect in 2 pilot case series. The aim of this study is to assess the effect of antisecretory factor in adult patients with severe traumatic brain injury as measured by 30-day mortality, treatment intensity level (TIL), and intracranial pressure (ICP).
Methods/design
This is a single-center, double-blind, randomized, placebo-controlled clinical phase 2 trial, investigating the clinical superiority of Salovum® given as a food supplement to adults with severe TBI (GCS < 9), presenting to the trauma unit at Tygerberg University Hospital, Cape Town, South Africa, that are planned for invasive ICP monitoring and neurointensive care, will be screened for eligibility, and assigned to either treatment group (
n
= 50) or placebo group (
n
= 50). In both groups, the primary outcome will be 30-day mortality, recorded via hospital charts, follow-up phone calls, and the population registry. Secondary outcomes will be treatment intensity level (TIL), scored from hospital charts, and ICP registered from hospital data monitoring.
Trial registration
ClinicalTrials.gov
NCT03339505
. Registered on September 17, 2017.
Protocol version 3.0 from November 13, 2020
Journal Article
The Swedish childhood tumor biobank: systematic collection and molecular characterization of all pediatric CNS and other solid tumors in Sweden
2023
The Swedish Childhood Tumor Biobank (BTB) is a nonprofit national infrastructure for collecting tissue samples and genomic data from pediatric patients diagnosed with central nervous system (CNS) and other solid tumors. The BTB is built on a multidisciplinary network established to provide the scientific community with standardized biospecimens and genomic data, thereby improving knowledge of the biology, treatment and outcome of childhood tumors. As of 2022, over 1100 fresh-frozen tumor samples are available for researchers. We present the workflow of the BTB from sample collection and processing to the generation of genomic data and services offered. To determine the research and clinical utility of the data, we performed bioinformatics analyses on next-generation sequencing (NGS) data obtained from a subset of 82 brain tumors and patient blood-derived DNA combined with methylation profiling to enhance the diagnostic accuracy and identified germline and somatic alterations with potential biological or clinical significance. The BTB procedures for collection, processing, sequencing, and bioinformatics deliver high-quality data. We observed that the findings could impact patient management by confirming or clarifying the diagnosis in 79 of the 82 tumors and detecting known or likely driver mutations in 68 of 79 patients. In addition to revealing known mutations in a broad spectrum of genes implicated in pediatric cancer, we discovered numerous alterations that may represent novel driver events and specific tumor entities. In summary, these examples reveal the power of NGS to identify a wide number of actionable gene alterations. Making the power of NGS available in healthcare is a challenging task requiring the integration of the work of clinical specialists and cancer biologists; this approach requires a dedicated infrastructure, as exemplified here by the BTB.
Journal Article
The effect of locally delivered cisplatin is dependent on an intact immune function in an experimental glioma model
2019
Several chemotherapeutic drugs are now considered to exert anti-tumour effects, by inducing an immune-promoting inflammatory response. Cisplatin is a potent chemotherapeutic agent used in standard medulloblastoma but not glioblastoma protocols. There is no clear explanation for the differences in clinical efficacy of cisplatin between medulloblastomas and glioblastomas, despite the fact that cisplatin is effective
in vitro
against the latter. Systemic toxicity is often dose limiting but could tentatively be reduced by intratumoral administration. We found that intratumoral cisplatin can cure GL261 glioma-bearing C57BL/6 mice and this effect was abolished in GL261-bearing NOD-scid
IL2rγ
null
(NSG) mice. Contrary to previous results with intratumoral temozolomide cisplatin had no additive or synergistic effect with whole cell either GL261 wild-type or GM-CSF-transfected GL261 cells whole cell vaccine-based immunotherapy. While whole tumour cell immunizations increased CD8
+
T-cells and decreased F4/80
+
macrophages intratumorally, cisplatin had no effect on these cell populations. Taken together, our results demonstrate that intratumoral cisplatin treatment was effective with a narrow therapeutic window and may be an efficient approach for glioma or other brain tumour treatment.
Journal Article