| 1. |
- Baryawno, Ninib, et al.
(author)
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Tumor-growth-promoting cyclooxygenase-2 prostaglandin E2 pathway provides medulloblastoma therapeutic targets
- 2008
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In: Neuro-Oncology. - : Oxford University Press (OUP). - 1522-8517 .- 1523-5866. ; 10:5, s. 661-674
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Journal article (peer-reviewed)abstract
- Prostaglandin E(2) (PGE(2)) has been shown to play important roles in several aspects of tumor development and progression. PGE(2) is synthesized from arachidonic acid by cyclooxygenases (COX) and prostaglandin E synthases (PGES) and mediates its biological activity through binding to the four prostanoid receptors EP(1) through EP(4). In this study, we show for the first time that medulloblastoma (MB), the most common malignant childhood brain tumor, expresses high levels of COX-2, microsomal prostaglandin E synthase-1, and EP(1) through EP(4) and secretes PGE(2). PGE(2) and the EP(2) receptor agonist butaprost stimulated MB cell proliferation. Treatment of MB cells with COX inhibitors suppressed PGE(2) production and induced caspase-dependent apoptosis. Similarly, specific COX-2 silencing by small interfering RNA inhibited MB cell growth. EP(1) and EP(3) receptor antagonists ONO-8713 and ONO-AE3-240, but not the EP(4) antagonists ONO-AE3-208 and AH 23848, inhibited tumor cell proliferation, indicating the significance of EP(1) and EP(3) but not EP(4) for MB growth. Administration of COX inhibitors at clinically achievable nontoxic concentrations significantly inhibited growth of established human MB xenografts. Apoptosis was increased, proliferation was reduced, and angiogenesis was inhibited in MBs treated with COX inhibitors. This study suggests that PGE(2) is important for MB growth and that therapies targeting the prostanoid metabolic pathway are potentially beneficial and should be tested in clinical settings for treatment of children with MB.
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| 2. |
- Gleissman, Helena, et al.
(author)
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Omega-3 fatty acid supplementation delays the progression of neuroblastoma in vivo
- 2011
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In: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 128:7, s. 1703-1711
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Journal article (peer-reviewed)abstract
- Epidemiological and preclinical studies have revealed that omega-3 fatty acids have anticancer properties. We have previously shown that the omega-3 fatty acid docosahexaenoic acid (DHA) induces apoptosis of neuroblastoma cells in vitro by mechanisms involving intracellular peroxidation of DHA by means of 15-lipoxygenase or autoxidation. In our study, the effects of DHA supplementation on neuroblastoma tumor growth in vivo were investigated using two complementary approaches. For the purpose of prevention, DHA as a dietary supplement was fed to athymic rats before the rats were xenografted with human neuroblastoma cells. For therapeutic purposes, athymic rats with established neuroblastoma xenografts were given DHA daily by gavage and tumor growth was monitored. DHA levels in plasma and tumor tissue were analyzed by gas liquid chromatography. DHA delayed neuroblastoma xenograft development and inhibited the growth of established neuroblastoma xenografts in athymic rats. A revised version of the Pediatric Preclinical Testing Program evaluation scheme used as a measurement of treatment response showed that untreated control animals developed progressive disease, whereas treatment with DHA resulted in stable disease or partial response, depending on the DHA concentration. In conclusion, prophylactic treatment with DHA delayed neuroblastoma development, suggesting that DHA could be a potential agent in the treatment of minimal residual disease and should be considered for prevention in selected cases. Treatment results on established aggressive neuroblastoma tumors suggest further studies aiming at a clinical application in children with high-risk neuroblastoma.
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| 3. |
- Granholm, Linnea, et al.
(author)
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Episodic Ethanol Exposure in Adolescent Rats Causes Residual Alterations in Endogenous Opioid Peptides
- 2018
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In: Frontiers in Psychiatry. - : FRONTIERS MEDIA SA. - 1664-0640. ; 9
-
Journal article (peer-reviewed)abstract
- Adolescent binge drinking is associated with an increased risk of substance use disorder, but how ethanol affects the central levels of endogenous opioid peptides is still not thoroughly investigated. The aim of this study was to examine the effect of repeated episodic ethanol exposure during adolescence on the tissue levels of three different endogenous opioid peptides in rats. OutbredWistar rats received orogastric (i.e., gavage) ethanol for three consecutive days per week between 4 and 9 weeks of age. At 2 h and 3 weeks, respectively, after the last exposure, beta-endorphin, dynorphin B and Met-enkephalin-Arg(6)Phe(7) (MEAP) were analyzed with radioimmunoassay. Beta-endorphin levels were low in the nucleus accumbens during ethanol intoxication. Remaining effects of adolescent ethanol exposure were found especially for MEAP, with low levels in the amygdala, and high in the substantia nigra and ventral tegmental area three weeks after the last exposure. In the hypothalamus and pituitary, the effects of ethanol on beta-endorphin were dependent on time from the last exposure. An interaction effect was also found in the accumbal levels of MEAP and nigral dynorphin B. These results demonstrate that repeated episodic exposure to ethanol during adolescence affected opioid peptide levels in regions involved in reward and reinforcement as well as stress response. These alterations in opioid networks after adolescent ethanol exposure could explain, in part, the increased risk for high ethanol consumption later in life.
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| 4. |
- Granholm, Linnea, et al.
(author)
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Impact of adolescent ethanol exposure and adult amphetamine self-administration on evoked striatal dopamine release in male rats
- 2015
-
In: Psychopharmacology. - : Springer Science and Business Media LLC. - 0033-3158 .- 1432-2072. ; 232:24, s. 4421-4431
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Journal article (peer-reviewed)abstract
- Adolescent binge drinking is common and associated with increased risk of substance use disorders. Transition from recreational to habitual ethanol consumption involves alterations in dorsal striatal function, but the long-term impact of adolescent ethanol exposure upon this region remains unclear. This study aimed to characterise and describe relationships between adolescent ethanol exposure, amphetamine self-administration and adult dopamine dynamics in dorsal striatum, including response to amphetamine challenge, in male Wistar rats. Ethanol (2 g/kg) or water was administered intragastrically in an episodic binge-like regimen (three continuous days/week) between 4 and 9 weeks of age (i.e. post-natal days 28-59). In adulthood, animals were divided into two groups. In the first, dorsal striatal potassium-evoked dopamine release was examined via chronoamperometry, in the basal state and after a single amphetamine challenge (2 mg/kg, i.v.). In the second, amphetamine self-administration behaviour was studied (i.e. fixed and progressive ratio) before chronoamperometric analysis was conducted as described above. Adolescent ethanol exposure suppressed locally evoked dopamine response after amphetamine challenge in adulthood, whereas in the basal state, no differences in dopamine dynamics were detected. Ethanol-exposed animals showed no differences in adult amphetamine self-administration behaviour but an abolished effect on dopamine removal in response to a single amphetamine challenge after self-administration. Amphetamine challenges in adult rats revealed differences in in vivo dopamine function after adolescent ethanol exposure. The attenuated drug response in ethanol-exposed animals may affect habit formation and contribute to increased risk for substance use disorders as a consequence of adolescent ethanol.
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| 5. |
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| 6. |
- Momeni, Shima, et al.
(author)
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Supplier-dependent differences in intermittent voluntary alcohol intake and response to naltrexone in Wistar rats
- 2015
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In: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 9
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Journal article (peer-reviewed)abstract
- Alcohol use disorder (AUD) is a worldwide public health problem and a polygenetic disorder displaying substantial individual variation. This work aimed to study individual differences in behavior and its association to voluntary alcohol intake and subsequent response to naltrexone in a seamless heterogenic group of animals. Thus, by this approach the aim was to more accurately recapitulate the existing heterogeneity within the human population. Male Wistar rats from three different suppliers (Harlan Laboratories B.V., RccHan™:WI; Taconic Farms A/S, HanTac:WH; and Charles River GmbH, Crl:WI) were used to create a heterogenic group for studies of individual differences in behavior, associations to intermittent voluntary alcohol intake and subsequent response to naltrexone. The rats were tested in the open field prior to the Y-maze and then given voluntary intermittent access to alcohol or water in the home cage for 6 weeks, where after, naltrexone in three different doses or saline was administered in a Latin square design over 4 weeks and alcohol intake and preference was measured. However, supplier-dependent differences and concomitant skew subgroup formations, primarily in open field behavior and intermittent alcohol intake, resulted in a shifted focus to instead study voluntary alcohol intake and preference, and the ensuing response to naltrexone in Wistar rats from three different suppliers. The results showed that outbred Wistar rats are diverse with regard to voluntary alcohol intake and preference in a supplier-dependent manner; higher in RccHan™:WI relative to HanTac:WH and Crl:WI. The results also revealed supplier-dependent differences in the effect of naltrexone that were dose- and time-dependent; evident differences in high-drinking RccHan™:WI rats relative to HanTac:WH and Crl:WI rats. Overall these findings render RccHan™:WI rats more suitable for studies of individual differences in voluntary alcohol intake and response to naltrexone and further highlight the inherent heterogeneity of the Wistar strain. The overall results put focus on the importance of thoroughly considering the animals used to aid in study design and for comparison of reported results.
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| 7. |
- Mortensen, Anja, et al.
(author)
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Selection, characterization and in vivo evaluation of novel CD44v6-targeting antibodies for targeted molecular radiotherapy
- 2023
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In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
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Journal article (peer-reviewed)abstract
- Molecular radiotherapy combines the advantages of systemic administration of highly specific antibodies or peptides and the localized potency of ionizing radiation. A potential target for molecular radiotherapy is the cell surface antigen CD44v6, which is overexpressed in numerous cancers, with limited expression in normal tissues. The aim of the present study was to generate and characterize a panel of human anti-CD44v6 antibodies and identify a suitable candidate for future use in molecular radiotherapy of CD44v6-expressing cancers. Binders were first isolated from large synthetic phage display libraries containing human scFv and Fab antibody fragments. The antibodies were extensively analyzed through in vitro investigations of binding kinetics, affinity, off-target binding, and cell binding. Lead candidates were further subjected to in vivo biodistribution studies in mice bearing anaplastic thyroid cancer xenografts that express high levels of CD44v6. Additionally, antigen-dependent tumor uptake of the lead candidate was verified in additional xenograft models with varying levels of target expression. Interestingly, although only small differences were observed among the top antibody candidates in vitro, significant differences in tumor uptake and retention were uncovered in in vivo experiments. A high-affinity anti-CD44v6 lead drug candidate was identified, mAb UU-40, which exhibited favorable target binding properties and in vivo distribution. In conclusion, a panel of human anti-CD44v6 antibodies was successfully generated and characterized in this study. Through comprehensive evaluation, mAb UU-40 was identified as a promising lead candidate for future molecular radiotherapy of CD44v6-expressing cancers due to its high affinity, excellent target binding properties, and desirable in vivo distribution characteristics.
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| 8. |
- Ponthan, Frida, et al.
(author)
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Celecoxib Prevents Neuroblastoma Tumor Development and Potentiates the Effect of Chemotherapeutic Drugs In vitro and In vivo
- 2007
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In: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 13:3, s. 1036-1044
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Journal article (peer-reviewed)abstract
- Purpose: Neuroblastoma is the most common and deadly solid tumor of childhood. Cyclooxygenase-2 is expressed in clinical neuroblastoma tumors and cell lines and inhibitors of this enzyme induce apoptosis in human neuroblastoma cells in vitro and in neuroblastoma xenografts in vivo. We hypothesized that the cyclooxygenase-2- specific inhibitor celecoxib could enhance the cytotoxic effect of chemotherapeutic drugs currently used in neuroblastoma treatment. Furthermore, we investigated if prophylactic treatment with celecoxib could prevent neuroblastoma tumor development in vivo. Experimental Design: Neuroblastoma cell cytotoxicity of chemotherapeutic drugs in combination with celecoxib was examined. In vivo, athymic rats carrying established SH-SY5Y xenografts were treated with celecoxib in combination with irinotecan, doxorubicin or etoposide, or with either drug alone. For prevention studies, rats received celecoxib in the diet, 250 to 2,500 ppm, from the time of tumor cell injection. Results: Celecoxib induced a synergistic or an additive cytotoxic effect in combination with doxorubicin, etoposide, irinotecan or vincristine in vitro. In vivo, treatment with celecoxib in combination with irinotecan or doxorubicin induced a significant growth inhibition of established neuroblastoma tumors. Rats receiving celecoxib in the diet showed a distinct dose-dependent delay in tumor development compared with untreated rats. Plasma levels of celecoxib were comparable with levels obtainable in humans. Conclusions: Celecoxib potentiates the antitumor effect of chemotherapeutic drugs currently used in neuroblastoma treatment, which argues for clinical trials combining these drugs. Celecoxib could also be a potential drug for treatment of minimal residual disease.
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| 9. |
- Rasmuson, Agnes, et al.
(author)
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Tumor Development, Growth Characteristics and Spectrum of Genetic Aberrations in the TH-MYCN Mouse Model of Neuroblastoma
- 2012
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:12
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Journal article (peer-reviewed)abstract
- Background: The TH-MYCN transgenic neuroblastoma model, with targeted MYCN expression to the developing neural crest, has been used to study neuroblastoma development and evaluate novel targeted tumor therapies. Methods: We followed tumor development in 395 TH-MYCN (129X1/SvJ) mice (125 negative, 206 hemizygous and 64 homozygous mice) by abdominal palpations up to 40 weeks of age. DNA sequencing of MYCN in the original plasmid construct and mouse genomic DNA was done to verify the accuracy. Copy number analysis with Affymetrix(R) Mouse Diversity Genotyping Arrays was used to characterize acquired genetic aberrations. Results: DNA sequencing confirmed presence of human MYCN cDNA in genomic TH-MYCN DNA corresponding to the original plasmid construct. Tumor incidence and growth correlated significantly to transgene status with event-free survival for hemizygous mice at 50%, and 0% for homozygous mice. Hemizygous mice developed tumors at 5.6-19 weeks (median 9.1) and homozygous mice at 4.0-6.9 weeks (5.4). The mean treatment window, time from palpable tumor to sacrifice, for hemizygous and homozygous mice was 15 and 5.2 days, respectively. Hemizygous mice developing tumors as early as homozygous mice had a longer treatment window. Age at tumor development did not influence treatment window for hemizygous mice, whereas treatment window in homozygous mice decreased significantly with increasing age. Seven out of 10 analysed tumors had a flat DNA profile with neither segmental nor numerical chromosomal aberrations. Only three tumors from hemizygous mice showed acquired genetic features with one or more numerical aberrations. Of these, one event corresponded to gain on the mouse equivalent of human chromosome 17. Conclusion: Hemizygous and homozygous TH-MYCN mice have significantly different neuroblastoma incidence, tumor growth characteristics and treatment windows but overlap in age at tumor development making correct early genotyping essential to evaluate therapeutic interventions. Contrasting previous studies, our data show that TH-MYCN tumors have few genetic aberrations.
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| 10. |
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| 11. |
- Segerström, Lova, et al.
(author)
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Effects of radiation on growth of two human tumour cell lines surviving a previous high dose, low dose-rate, radionuclide exposure
- 2008
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In: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 33:2, s. 341-9
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Journal article (peer-reviewed)abstract
- Effects of radiation on growth of two human tumour cell lines that survived a previous high dose, low dose-rate radionuclide exposure simulating intensive radionuclide therapy, were analyzed. The purpose was to investigate whether the survivors gained therapy induced changes in growth and radiation response. The U118MG, ParRes (parental resistant), and U373MG, ParSen (parental sensitive), glioma cells were used because they are known to be low dose-rate radiation resistant and sensitive, respectively. These cells were initially exposed to high dose, low dose-rate radiation for 24 h and surviving U118MG and U373MG cells formed new cultures called SurRes (surviving resistant) and SurSen (surviving sensitive), respectively. All four cell types were then exposed to graded acute radiation doses, 0-8 Gy, and analyzed for radiation induced growth disturbances. They were also analyzed regarding DNA-content and cell cycle distributions. The SurRes cells regained in most cases the same growth rate, had the same growth delays and showed generally a similar response as the original ParRes cells to the 0-8 Gy exposures. In contrast, the SurSen cells had in all cases slower growth rate and longer growth delays than the original ParSen cells after the 0-8 Gy exposures. There were no signs of radiation-induced radioresistance. The slow growing SurSen cells contained about 80% more DNA and had more cells in G1 and fewer in G2 than the ParSen cells. The conclusion is that tumour cells surviving high dose, low dose-rate, radionuclide therapy, afterwards can react differently to a new radiation exposure.
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| 12. |
- Segerström, Lova, et al.
(author)
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Minimizing Postsampling Degradation of Peptides by a Thermal Benchtop Tissue Stabilization Method.
- 2016
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In: Biopreservation and Biobanking. - : Mary Ann Liebert Inc. - 1947-5535 .- 1947-5543. ; 14:2, s. 172-179
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Journal article (peer-reviewed)abstract
- Enzymatic degradation is a major concern in peptide analysis. Postmortem metabolism in biological samples entails considerable risk for measurements misrepresentative of true in vivo concentrations. It is therefore vital to find reliable, reproducible, and easy-to-use procedures to inhibit enzymatic activity in fresh tissues before subjecting them to qualitative and quantitative analyses. The aim of this study was to test a benchtop thermal stabilization method to optimize measurement of endogenous opioids in brain tissue. Endogenous opioid peptides are generated from precursor proteins through multiple enzymatic steps that include conversion of one bioactive peptide to another, often with a different function. Ex vivo metabolism may, therefore, lead to erroneous functional interpretations. The efficacy of heat stabilization was systematically evaluated in a number of postmortem handling procedures. Dynorphin B (DYNB), Leu-enkephalin-Arg(6) (LARG), and Met-enkephalin-Arg(6)-Phe(7) (MEAP) were measured by radioimmunoassay in rat hypothalamus, striatum (STR), and cingulate cortex (CCX). Also, simplified extraction protocols for stabilized tissue were tested. Stabilization affected all peptide levels to varying degrees compared to those prepared by standard dissection and tissue handling procedures. Stabilization increased DYNB in hypothalamus, but not STR or CCX, whereas LARG generally decreased. MEAP increased in hypothalamus after all stabilization procedures, whereas for STR and CCX, the effect was dependent on the time point for stabilization. The efficacy of stabilization allowed samples to be left for 2 hours in room temperature (20°C) without changes in peptide levels. This study shows that conductive heat transfer is an easy-to-use and efficient procedure for the preservation of the molecular composition in biological samples. Region- and peptide-specific critical steps were identified and stabilization enabled the optimization of tissue handling and opioid peptide analysis. The result is improved diagnostic and research value of the samples with great benefits for basic research and clinical work.
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| 13. |
- Segerström, Lova Perup
(author)
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Novel experimental targeted therapy of neuroblastoma
- 2009
-
Doctoral thesis (other academic/artistic)abstract
- Neuroblastoma, a malignancy of the sympathetic nervous system, is the most common solid extracranial tumor of infancy and is responsible for around 15% of the cancer-related deaths in children. For the entire group the survival has increased over the last decades, but despite today's intense muti-modal therapy the survival of high-risk neuroblastomas lies just around 50%. Therefore, novel treatment options are urgently needed and awaited. The development of novel cancer therapies has geared up with more and more agents entering trials and become clinically available, but this has predominately been directed towards the adult oncology area. Hopefully, legal directives will act as a 'carrot and a stick' on companies to take more interest in the pediatric area. There are concerns, with all rights, about how much efficacy a novel drug should need to show before it can be justified to move into the clinic. Preclinical animal models of cancer have established their role in the evaluation of these agents. But there is everlasting uncertainty about how truly they represent all or parts of a particular disease, and if in vivo efficacy is predictive of clinical value. This thesis describes the investigation of six novel targeted therapies, evaluated in vitro and in vivo in neuroblastoma. Anti-angiogenic antibody-therapy with bevacizumab (Avastin®) showed efficacy in vivo in three neuroblastoma xenograft models. Primary material from neuroblastoma was shown to express activated Akt and mTOR. Inhibition of the mTOR signalling pathway with rapamycin (Rapamune®) or its novel analogue CCI-779 (Torisel®) showed promising potential in vitro and in vivo, where the most interesting finding was that MYCN-amplified or over expressing cells were more sensitive. Upon treatment in vitro and in vivo we observed a down regulation of MYCN and cyclin D1 protein. Inhibition of the upstream signalling pathway with the PDK1 inhibitor OSU03012 or the dual PI3K/mTOR inhibitor PI103 did also show promising effects in vitro and in vivo. The major finding was that inhibition upstream of mTOR seemed most effective in MYCN-amplified or over expressing cells. As observed previously, treatment was associated with a down regulation of MYCN and cyclin D1 proteins. Targeting the MYCN protein with the Myc-Max disruptor 10058-F4 had effect in vitro. There were modest effects of 10058-F4 in vivo on a MYCN-amplified xenograft model, whereas in vivo in the transgenic MYCN-driven model of neuroblastoma, 10058-F4 showed some interesting potential. In summary, this thesis suggests that targeting angiogenesis in neuroblastoma appear as an interesting strategy. Primary neuroblastoma seems to be over expressing key proteins in the PI3K/Akt/mTOR pathway and targeting these with inhibitors seems to have efficacy, especially in the context of a MYCN-amplification or over expression. Also, interfering with the MYCN protein appears as an interesting approach. Some of these compounds are currently easing their way into the pediatric oncology area and hopefully in the future they, and the results generated in this thesis, will aid in improving the survival of children with neuroblastoma.
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| 14. |
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| 15. |
- Segerström, Lova, et al.
(author)
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The Anti-VEGF Antibody Bevacizumab Potently Reduces the Growth Rate of High-Risk Neuroblastoma Xenografts
- 2006
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In: Pediatric Research. - : Springer Science and Business Media LLC. - 0031-3998 .- 1530-0447. ; 60:5, s. 576-581
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Journal article (peer-reviewed)abstract
- Neuroblastoma (NB) is a rapidly growing, well-vascularized childhood cancer that often presents with metastases. The overall five-year survival in NB is approximately 45% despite multimodality treatment, and therefore there is a clinical need for new therapeutic strategies. NB frequently overexpresses the angiogenic factor VEGF (vascular endothelial growth factor). The aim of this study was to investigate the effect of bevacizumab (Avastin, Genentech/Roche), a humanized anti-VEGF-A antibody, on NB growth in three different xenograft models, chosen to resemble high-risk NB. The human NB cell lines SK-N-AS, IMR-32 and SH-SY5Y, which are poorly differentiated and overexpress VEGF-A, were injected s.c. in immunodeficient mice. Bevacizumab was given intraperitoneally twice weekly at 5 mg/kg body weight, starting at a tumor volume of 0.3 mL. Bevacizumab significantly (p < 0.01-0.05) reduced NB growth in vivo without toxicity by causing a 30-63% reduction of angiogenesis, but had no effect on NB cell survival in vitro. Serum concentrations of VEGF-A increased two- to six-fold during bevacizumab therapy which did not result in faster tumor growth compared with control animals. Based on our experimental data we suggest consideration of bevacizumab in treatment of high-risk NB that does not respond to conventional therapy and that overexpresses VEGF.
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| 16. |
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| 17. |
- Wickström, Malin, et al.
(author)
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The novel melphalan prodrug J1 inhibits neuroblastoma growth in vitro and in vivo
- 2007
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In: Molecular Cancer Therapeutics. - 1535-7163 .- 1538-8514. ; 6:9, s. 2409-2417
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Journal article (peer-reviewed)abstract
- Neuroblastoma is the most common extracranial solid tumor of childhood. The activity of J1 (l-melphalanyl-p-l-fluorophenylalanine ethyl ester), an enzymatically activated melphalan prodrug, was evaluated in neuroblastoma models in vitro and in vivo. Seven neuroblastoma cell lines with various levels of drug resistance were screened for cytotoxicity of J1 alone or in combination with standard cytotoxic drugs, using a fluorometric cytotoxicity assay. J1 displayed high cytotoxic activity in vitro against all neuroblastoma cell lines, with IC50 values in the submicromolar range, significantly more potent than melphalan. The cytotoxicity of J1, but not melphalan, could be significantly inhibited by the aminopeptidase inhibitor bestatin. J1 induced caspase-3 cleavage and apoptotic morphology, had additive effects in combination with doxorubicin, cyclophosphamide, carboplatin, and vincristine, and synergistically killed otherwise drug-resistant cells when combined with etoposide. Athymic rats and mice carrying neuroblastoma xenografts [SH-SY5Y, SK-N-BE(2)] were treated with equimolar doses of melphalan, J1, or no drug, and effects on tumor growth and tissue morphology were analyzed. Tumor growth in vivo was significantly inhibited by J1 compared with untreated controls. Compared with melphalan, J1 more effectively inhibited the growth of mice with SH-SY5Y xenografts, was associated with higher caspase-3 activation, fewer proliferating tumor cells, and significantly decreased mean vascular density. In conclusion, the melphalan prodrug J1 is highly active in models of neuroblastoma in vitro and in vivo, encouraging further clinical development in this patient group.
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