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- Spetz, Johan, et al.
(författare)
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Effects of internal irradiation from 177Lu-octreotate on transcriptional expression in GOT1 midgut carcinoid in nude mice
- 2014
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Ingår i: SweRays Workshop, Malmö, Sweden, Aug 20-22.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Neuroendocrine (NE) tumors expressing somatostatin receptors (SSTR) are often treated with 177Lu-octreotate. The treatment is highly successful in animal models, but low cure rates in clinical studies suggests optimization of treatment protocol is needed. Little is known about which cellular responses play a crucial role in neuroendocrine tumors after irradiation. It is therefore important to identify the effects of 177Lu-octreotate on biological functions for future optimization of treatment parameters and the identification of biomarkers predicting treatment response. The aim of this study was to investigate the transcriptional response of GOT1 midgut carcinoid in nude mice following 177Lu-octreotate treatment. Methods: GOT1 bearing BALB/c nude mice were i.v. injected with 15 MBq 177Lu-octreotate and tumor size was measured twice a week using calipers. Animals were killed after 1, 3, 7 or 41 days and tumor samples excised and snap frozen in liquid nitrogen. Total RNA was extracted from tumor samples and subjected to Illumina microarray expression analysis. Differential transcriptional profiles were identified by comparing treated and untreated tumor samples using Nexus Expression 3.0 software. Associated biological functions and biological pathways (according to Gene Ontology terms) were compared using Nexus Expression 3.0 and Ingenuity IPA. Results: The mean tumor volume was clearly reduced after 177Lu-octreotate treatment. Microarray analysis showed clear difference in regulation pattern between the time points. The analysis of associated biological functions revealed clear effect on cell death and survival, and cell cycle after 1, 3, and 7 days, while cellular movement and cellular development were clearly influenced after 41 days. Cellular growth and proliferation was also affected after 1 day but not at the other time points studied. Conclusions: : Analysis of the transcriptional regulation in GOT1 tumors in nude mice following 177Lu-octreotate treatment revealed responses in different cellular functions that were distinct for each time point. These findings indicate potential venues for increasing clinical effectiveness of midgut carcinoid therapy with 177Lu-octreotate.
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| 3. |
- Langen, Britta, et al.
(författare)
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Transcriptional gene regulation in abdominal organs and the lung after i.v. injection of 211At in mouse
- 2012
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Ingår i: Radiation research society. San Juan, Puerto Rico. 2012.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Astatine-211 (211At) is a promising radionuclide for radiation therapy with a nearly optimal biological effectiveness of emitted α-particles. Despite its potential, few studies have analysed 211At-induced normal tissue responses in vivo. In order to determine the quality and extent of 211At-induced cellular responses in vivo, the transcriptional gene regulation was analysed in the kidney cortex and medulla, liver, lung, and spleen. Female BALB/c nude mice were i.v. injected with 0.064, 0.64, 1.8, 14, and 42 kBq 211At and killed after 24h. Respective organs were excised and stored at -80°C until further analysis. Extracted total RNA was analysed with the Illumina MouseRef-8 Whole Genome Beadchip platform and data processing was performed with Nexus Expression 2.0. A common strong decrease in the total number of regulated transcripts was seen between 0.64 and 1.8 kBq 211At corresponding to absorbed doses between 2 and 50 mGy for all investigated tissues. Only minor responses in previously identified radiation-associated transcripts could be observed at any exposure. Among tissues at similar absorbed dose levels, the similarity in transcript up- and down-regulation decreased with increased absorbed dose. This phenomenon was more pronounced when the increase in absorbed dose corresponded also to an increase between 0.64 and 1.8 kBq 211At. Biological processes associated with regulated transcripts were categorised to assess the regulatory profiles in each tissue at a given exposure. These profiles showed distinct patterns which mirrored the threshold behaviour on the categorical and sub-categorical level of biological processes. The strong regulatory change demonstrated at the low absorbed doses in the tissues studied might be due to both radiation-induced effects of each tissue and physiological response from radiation-induced effects on the 211At-accumulating thyroid gland. These findings demonstrate the complexity of responses in vivo and highlight the need for a better understanding of the physiology when studying effects of ionizing radiation exposure.
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| 4. |
- Schüler, Emil, et al.
(författare)
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Biological effects of 177Lu-octreotate therapy in mouse: in vivo normal kidney tissue response evaluated with gene expression microarray
- 2012
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Ingår i: 58th Annual Meeting of the Radiation Research Society. San Juan, Puerto Rico. 2012.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The kidneys are the dose limiting organ when patients undergo 177Lu-octreotate therapy. The purpose of the present study was to investigate alterations in gene expression levels in the kidney following exposure to various absorbed doses of 177Lu. Female Balb/c mice were i.v. injected with 1.3-140 MBq 177Lu-octreotate, corresponding to an absorbed dose to the kidneys of 0.13-13 Gy. Control animals did not receive any 177Lu-octreotate. The animals were killed 24 hours after injection and the kidneys were removed, followed by dissection of the kidney medulla and cortex. Total RNA was extracted and processed using the Illumina Mouse-Ref-8 Whole-Genome Expression Beadchips to identify differentially expressed transcripts between irradiated and non-irradiated kidney tissues. The total number of differentially regulated transcripts was 480 and 281 in the kidney medulla and cortex, respectively. Of these, 39 and 32 transcripts were regulated at all absorbed doses in the two renal tissues. Of the affected biological processes, three and five processes were affected at all absorbed dose levels in the medulla and cortex, respectively; glycerol metabolism, immune response, and defense response in the medulla, and immune response, amino acid transport, circadian rhythm, rhythmic processes, and regulation of lipoprotein lipase activity in the cortex. In general, metabolic processes were strongly expressed at all absorbed dose levels studied, however, inversely related to increasing absorbed dose. Furthermore, cellular and developmental processes were strongly associated with kidney medulla, while a strong association with transport and immune response was seen in kidney cortex. The results demonstrate distinct differences in the response seen after 177Lu exposure to different absorbed doses. Effects on metabolism and stress responses were frequently seen, while no processes associated with maintaining DNA integrity were found, which indicates a very diverse response following 177Lu exposure.
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| 8. |
- Spetz, Johan, et al.
(författare)
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Spatial proteomic analysis of GOT1 human small intestine neuroendocrine tumor in nude mice following 177Lu-octreotate therapy
- 2016
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Ingår i: 62nd Annual International Meeting Radiation Research Society, Waikoloa, HI, USA, October 16-19, 2016.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background: 177Lu-octreotate can be used for therapy of somatostatin receptor expressing neuroendocrine tumors (NET). 177Lu-octreotate therapy has achieved high cure rates in GOT1 (human small intestine NET) transplanted to nude mice. However, clinical studies result in moderate response, and complete tumor remission is rarely seen. Solid tumors often develop necrotic cores during growth due to e.g. insufficient vascularization, which may account for the different uptake kinetics and varying therapeutic success seen after 177Lu-octreotate treatment. It is therefore important to explore the cellular effects of 177Lu-octreotate to further optimize treatment parameters and identify biomarkers for treatment response assessment. Aim: To detect significant changes in protein profiles from peripheral and central samples of GOT1 tumor after 177Lu-octreotate therapy. Methods: GOT1 bearing BALB/c nude mice were i.v. injected with 15 MBq 177Lu-octreotate (corresponding to 4 Gy tumor absorbed dose) and killed after 13 days. Total cellular proteins were extracted from the peripheral and central parts of surgically excised tumor samples. Proteomic profiling was generated using liquid chromatography tandem-mass spectrometry (LC-MS/MS), followed by database-based protein identification and relative quantification. Functional annotation of proteins was performed using the DAVID bioinformatics resource tool. Results: The LC-MS/MS analysis identified 58 differentially expressed proteins (p<0.05, Fold Change>1.2) between the peripheral and central parts of tumor samples. Forty of these showed higher levels in the peripheral compared with the central samples, and among them were proteins associated with blood vessel/vasculature development (e.g. FAK1, H6ST1, LMA4, and SYWM), regulation of cell cycle and apoptosis (e.g. FAK1 and MK01), and cellular integrity (e.g. PDLI5, CALD1, FERM2, and NEB2). Conclusions: Taken together, these findings suggest spatial differences in tumor response to 177Lu-octreotate, mainly constituted by differences in vascularization and cellular integrity. These findings indicate potential venues for prognostic evaluation of NET therapy using 177Lu-octreotate. However, further studies are needed to determine whether these effects are time- and/or dose-dependent.
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| 9. |
- Larsson, Malin, et al.
(författare)
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Long-term transcriptomic and proteomic effects in Sprague Dawley rat thyroid and plasma after internal low dose 131I exposure.
- 2020
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 15:12
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Tidskriftsartikel (refereegranskat)abstract
- Radioiodide (131I) is commonly used to treat thyroid cancer and hyperthyroidis.131I released during nuclear accidents, have resulted in increased incidence of thyroid cancer in children. Therefore, a better understanding of underlying cellular mechanisms behind 131I exposure is of great clinical and radiation protection interest. The aim of this work was to study the long-term dose-related effects of 131I exposure in thyroid tissue and plasma in young rats and identify potential biomarkers.Male Sprague Dawley rats (5-week-old) were i.v. injected with 0.5, 5.0, 50 or 500 kBq 131I (Dthyroid ca 1-1000 mGy), and killed after nine months at which time the thyroid and blood samples were collected. Gene expression microarray analysis (thyroid samples) and LC-MS/MS analysis (thyroid and plasma samples) were performed to assess differential gene and protein expression profiles in treated and corresponding untreated control samples. Bioinformatics analyses were performed using the DAVID functional annotation tool and Ingenuity Pathway Analysis (IPA). The gene expression microarray data and LC-MS/MS data were validated using qRT-PCR and ELISA, respectively.Nine 131I exposure-related candidate biomarkers (transcripts: Afp and RT1-Bb, and proteins: ARF3, DLD, IKBKB, NONO, RAB6A, RPN2, and SLC25A5) were identified in thyroid tissue. Two dose-related protein candidate biomarkers were identified in thyroid (APRT and LDHA) and two in plasma (DSG4 and TGM3). Candidate biomarkers for thyroid function included the ACADL and SORBS2 (all activities), TPO and TG proteins (low activities). 131I exposure was shown to have a profound effect on metabolism, immune system, apoptosis and cell death. Furthermore, several signalling pathways essential for normal cellular function (actin cytoskeleton signalling, HGF signalling, NRF2-mediated oxidative stress, integrin signalling, calcium signalling) were also significantly regulated.Exposure-related and dose-related effects on gene and protein expression generated few expression patterns useful as biomarkers for thyroid function and cancer.
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| 10. |
- Langen, Britta, et al.
(författare)
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Transcriptional response in normal mouse tissues after i.v. 211At administration - response related to absorbed dose, dose rate, and time
- 2015
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Ingår i: EJNMMI Research. - : Springer Science and Business Media LLC. - 2191-219X .- 2191-219X. ; 5:1, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- Background In cancer radiotherapy, knowledge of normal tissue responses and toxicity risks is essential in order to deliver the highest possible absorbed dose to the tumor while maintaining normal tissue exposure at non-critical levels. However, few studies have investigated normal tissue responses in vivo after 211At administration. In order to identify molecular biomarkers of ionizing radiation exposure, we investigated genome-wide transcriptional responses to (very) low mean absorbed doses from 211At in normal mouse tissues. Methods Female BALB/c nude mice were intravenously injected with 1.7 kBq 211At and killed after 1 h, 6 h, or 7 days or injected with 105 or 7.5 kBq and killed after 1 and 6 h, respectively. Controls were mock-treated. Total RNA was extracted from tissue samples of kidney cortex and medulla, liver, lungs, and spleen and subjected to microarray analysis. Enriched biological processes were categorized after cellular function based on Gene Ontology terms. Results Responses were tissue-specific with regard to the number of significantly regulated transcripts and associated cellular function. Dose rate effects on transcript regulation were observed with both direct and inverse trends. In several tissues, Angptl4, Per1 and Per2, and Tsc22d3 showed consistent transcript regulation at all exposure conditions. Conclusions This study demonstrated tissue-specific transcriptional responses and distinct dose rate effects after 211At administration. Transcript regulation of individual genes, as well as cellular responses inferred from enriched transcript data, may serve as biomarkers in vivo. These findings expand the knowledge base on normal tissue responses and may help to evaluate and limit side effects of radionuclide therapy. Keywords: Astatine-211; Ionizing radiation; Normal tissue response; Radionuclide therapy; Biomarke
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