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Histology-Based Radiomics for [ 18F]FDG PET Identifies Tissue Heterogeneity in Pancreatic Cancer. J Nucl Med 2024:jnumed.123.266262. [PMID: 38782455 DOI: 10.2967/jnumed.123.266262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 04/22/2024] [Indexed: 05/25/2024] Open
Abstract
Radiomics features can reveal hidden patterns in a tumor but usually lack an underlying biologic rationale. In this work, we aimed to investigate whether there is a correlation between radiomics features extracted from [18F]FDG PET images and histologic expression patterns of a glycolytic marker, monocarboxylate transporter-4 (MCT4), in pancreatic cancer. Methods: A cohort of pancreatic ductal adenocarcinoma patients (n = 29) for whom both tumor cross sections and [18F]FDG PET/CT scans were available was used to develop an [18F]FDG PET radiomics signature. By using immunohistochemistry for MCT4, we computed density maps of MCT4 expression and extracted pathomics features. Cluster analysis identified 2 subgroups with distinct MCT4 expression patterns. From corresponding [18F]FDG PET scans, radiomics features that associate with the predefined MCT4 subgroups were identified. Results: Complex heat map visualization showed that the MCT4-high/heterogeneous subgroup was correlating with a higher MCT4 expression level and local variation. This pattern linked to a specific [18F]FDG PET signature, characterized by a higher SUVmean and SUVmax and second-order radiomics features, correlating with local variation. This MCT4-based [18F]FDG PET signature of 7 radiomics features demonstrated prognostic value in an independent cohort of pancreatic cancer patients (n = 71) and identified patients with worse survival. Conclusion: Our cross-modal pipeline allows the development of PET scan signatures based on immunohistochemical analysis of markers of a particular biologic feature, here demonstrated on pancreatic cancer using intratumoral MCT4 expression levels to select [18F]FDG PET radiomics features. This study demonstrated the potential of radiomics scores to noninvasively capture intratumoral marker heterogeneity and identify a subset of pancreatic ductal adenocarcinoma patients with a poor prognosis.
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Comparative Analysis of Morphological and Functional Effects of 225Ac- and 177Lu-PSMA Radioligand Therapies (RLTs) on Salivary Glands. Int J Mol Sci 2023; 24:16845. [PMID: 38069166 PMCID: PMC10706561 DOI: 10.3390/ijms242316845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/24/2023] [Accepted: 11/13/2023] [Indexed: 12/18/2023] Open
Abstract
Most Prostate Specific Membrane Antigens (PSMAs) targeting small molecules accumulate in the salivary glands (SGs), raising concerns about SG toxicity, especially after repeated therapies or therapy with 225Ac-labeled ligands. SG toxicity is assessed clinically by the severity of patient-reported xerostomia, but this parameter can be challenging to objectively quantify. Therefore, we explored the feasibility of using SG volume as a biomarker for toxicity. In 21 patients with late-stage metastatic resistant prostate cancer (mCRPC), the PSMA volume and ligand uptake of SG were analyzed retrospectively before and after two cycles of 177Lu-PSMA (LuPSMA; cohort A) and before and after one cycle of 225Ac-PSMA-617 (AcPSMA, cohort B). Mean Volume-SG in cohort A was 59 ± 13 vs. 54 ± 16 mL (-10%, p = 0.4), and in cohort B, it was 50 ± 13 vs. 40 ± 11 mL (-20%, p = 0.007), respectively. A statistically significant decrease in the activity concentration in the SG was only observed in group B (SUVmean: 9.2 ± 2.8 vs. 5.3 ± 1.8, p < 0.0001; vs. A: SUVmean: 11.2 ± 3.3 vs. 11.1 ± 3.5, p = 0.8). SG volume and PSMA-ligand uptake are promising markers to monitor the SG toxicity after a PSMA RLT.
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Improved Quality of Life in Metastatic Castration-Resistant Prostate Cancer Patients Receiving Consecutive Cycles of 177Lu-PSMA I&T. J Nucl Med 2023; 64:1765-1771. [PMID: 37678925 DOI: 10.2967/jnumed.123.265878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/01/2023] [Indexed: 09/09/2023] Open
Abstract
The aim of this retrospective analysis was to evaluate health-related quality of life (HRQoL) for patients with metastatic castration-resistant prostate cancer (mCRPC) receiving consecutive cycles of 177Lu-prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) using the reliable and validated European Organisation for Research and Treatment of Cancer core quality-of-life (QoL) questionnaire. In addition, differences in HRQoL between patients with early discontinuation of treatment because of disease progression and patients who were defined as eligible for treatment continuation were analyzed. Methods: In total, 60 mCRPC patients were included in this analysis. The European Organisation for Research and Treatment of Cancer core QoL questionnaire was completed at baseline, before each treatment cycle up to the sixth treatment cycle, and at the time of PSMA-ligand PET/CT scans after the second and fourth treatment cycles. QoL assessment included global health status, functional scales, and symptom burden during treatment. Results: Global health was significantly improved at the second and fourth cycles of 177Lu-PSMA RLT (P = 0.014 and P = 0.039, respectively). In line with this, role and emotional functioning showed significant improvements at the second and fourth treatment cycles (role functioning, P = 0.045 and P = 0.048, respectively, and emotional functioning, P = 0.035 and P = 0.007, respectively). In addition, compared with baseline, fatigue and pain were significantly alleviated at the second and fourth treatment cycles (pain, P = 0.035 and P = 0.034, respectively, and fatigue, P = 0.042 and P = 0.041, respectively). Other aspects of HRQoL, even if not significantly improved, remained stable over time, except for deterioration of fatigue at the study's end (P = 0.014) and reduction of dyspnea at the second treatment cycle (P = 0.012). Patients with early discontinuation of treatment showed a concordant decline in HRQoL. Conclusion: mCRPC patients showed significant improvement in HRQoL in the course of treatment with 177Lu-PSMA RLT. Furthermore, patients with early discontinuation of treatment showed an analogous decline in HRQoL.
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Artificial Intelligence in Oncological Hybrid Imaging. Nuklearmedizin 2023; 62:296-305. [PMID: 37802057 DOI: 10.1055/a-2157-6810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/08/2023]
Abstract
BACKGROUND Artificial intelligence (AI) applications have become increasingly relevant across a broad spectrum of settings in medical imaging. Due to the large amount of imaging data that is generated in oncological hybrid imaging, AI applications are desirable for lesion detection and characterization in primary staging, therapy monitoring, and recurrence detection. Given the rapid developments in machine learning (ML) and deep learning (DL) methods, the role of AI will have significant impact on the imaging workflow and will eventually improve clinical decision making and outcomes. METHODS AND RESULTS The first part of this narrative review discusses current research with an introduction to artificial intelligence in oncological hybrid imaging and key concepts in data science. The second part reviews relevant examples with a focus on applications in oncology as well as discussion of challenges and current limitations. CONCLUSION AI applications have the potential to leverage the diagnostic data stream with high efficiency and depth to facilitate automated lesion detection, characterization, and therapy monitoring to ultimately improve quality and efficiency throughout the medical imaging workflow. The goal is to generate reproducible, structured, quantitative diagnostic data for evidence-based therapy guidance in oncology. However, significant challenges remain regarding application development, benchmarking, and clinical implementation. KEY POINTS · Hybrid imaging generates a large amount of multimodality medical imaging data with high complexity and depth.. · Advanced tools are required to enable fast and cost-efficient processing along the whole radiology value chain.. · AI applications promise to facilitate the assessment of oncological disease in hybrid imaging with high quality and efficiency for lesion detection, characterization, and response assessment. The goal is to generate reproducible, structured, quantitative diagnostic data for evidence-based oncological therapy guidance.. · Selected applications in three oncological entities (lung, prostate, and neuroendocrine tumors) demonstrate how AI algorithms may impact imaging-based tasks in hybrid imaging and potentially guide clinical decision making..
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Clinical Translation of Targeted α-Therapy: An Evolution or a Revolution? J Nucl Med 2023; 64:685-692. [PMID: 37055224 DOI: 10.2967/jnumed.122.265353] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/10/2023] [Indexed: 04/15/2023] Open
Abstract
The field of radioligand therapy has advanced greatly in recent years, driven largely by β-emitting therapies targeting somatostatin receptor-expressing tumors and the prostate-specific membrane antigen. Now, more clinical trials are under way to evaluate α-emitting targeted therapies as potential next-generation theranostics with even higher efficacy due to their high linear energy and short range in human tissues. In this review, we summarize the important studies ranging from the first Food and Drug Administration-approved α-therapy, 223Ra-dichloride, for treatment of bone metastases in castration-resistant prostate cancer, including concepts in clinical translation such as targeted α-peptide receptor radiotherapy and 225Ac-PSMA-617 for treatment of prostate cancer, innovative therapeutic models evaluating new targets, and combination therapies. Targeted α-therapy is one of the most promising fields in novel targeted cancer therapy, with several early- and late-stage clinical trials for neuroendocrine tumors and metastatic prostate cancer already in progress, along with significant interest and investment in additional early-phase studies. Together, these studies will help us understand the short- and long-term toxicity of targeted α-therapy and potentially identify suitable therapeutic combination partners.
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Artificial Intelligence in Oncological Hybrid Imaging. ROFO-FORTSCHR RONTG 2023; 195:105-114. [PMID: 36170852 DOI: 10.1055/a-1909-7013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Artificial intelligence (AI) applications have become increasingly relevant across a broad spectrum of settings in medical imaging. Due to the large amount of imaging data that is generated in oncological hybrid imaging, AI applications are desirable for lesion detection and characterization in primary staging, therapy monitoring, and recurrence detection. Given the rapid developments in machine learning (ML) and deep learning (DL) methods, the role of AI will have significant impact on the imaging workflow and will eventually improve clinical decision making and outcomes. METHODS AND RESULTS The first part of this narrative review discusses current research with an introduction to artificial intelligence in oncological hybrid imaging and key concepts in data science. The second part reviews relevant examples with a focus on applications in oncology as well as discussion of challenges and current limitations. CONCLUSION AI applications have the potential to leverage the diagnostic data stream with high efficiency and depth to facilitate automated lesion detection, characterization, and therapy monitoring to ultimately improve quality and efficiency throughout the medical imaging workflow. The goal is to generate reproducible, structured, quantitative diagnostic data for evidence-based therapy guidance in oncology. However, significant challenges remain regarding application development, benchmarking, and clinical implementation. KEY POINTS · Hybrid imaging generates a large amount of multimodality medical imaging data with high complexity and depth.. · Advanced tools are required to enable fast and cost-efficient processing along the whole radiology value chain.. · AI applications promise to facilitate the assessment of oncological disease in hybrid imaging with high quality and efficiency for lesion detection, characterization, and response assessment. The goal is to generate reproducible, structured, quantitative diagnostic data for evidence-based oncological therapy guidance.. · Selected applications in three oncological entities (lung, prostate, and neuroendocrine tumors) demonstrate how AI algorithms may impact imaging-based tasks in hybrid imaging and potentially guide clinical decision making.. CITATION FORMAT · Feuerecker B, Heimer M, Geyer T et al. Artificial Intelligence in Oncological Hybrid Imaging. Fortschr Röntgenstr 2023; 195: 105 - 114.
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The prognostic role of 68Ga-PSMA11 PET-based response in prostate cancer patients undergoing taxane-based chemotherapy. J Nucl Med 2022:jnumed.122.264962. [PMID: 36581373 DOI: 10.2967/jnumed.122.264962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 12/06/2022] [Indexed: 12/31/2022] Open
Abstract
To assess the prognostic utility of conventional biochemical and imaging response criteria and 68Ga- prostate-specific membrane antigen (PSMA) 11 PET adapted or specific systems regarding overall survival (OS) in men with metastatic hormone-sensitive (mHSPC) and castration-resistant PC (mCRPC) treated with taxane-based chemotherapy. Methods: A total of 103 patients (pts) (n = 57 mHSPC, n = 46 mCRPC) underwent taxane-based chemotherapy. All patients had a minimum of two PSMA PET scans (at baseline and up to 3 months post-treatment). PSMA PET response was assessed by Response Evaluation Criteria in Solid Tumors (RECIST 1.1), adapted Prostate Cancer Working Group Criteria 3 (aPCWG3, using PSMA PET instead of bone scan), adapted Positron Emission Tomography Response Criteria in Solid Tumors (aPERCIST) and PSMA PET Progression (PPP) criteria. Response by each criterion was stratified by either progressive disease (PD) versus non-PD. For aPERCIST, stratification by PD, stable disease (SD) and partial/complete remission (PR/CR) was performed. Biochemical response was determined by PSA decline ≥50%. Subgroup analyses were performed by castration-status. Univariable cox proportional hazard regression analyses including Harrell's concordance indices were calculated to investigate the association of PD by response criteria and OS. Kaplan-Meier tests including log-rank statistics were calculated for survival analyses. Results: 26 (25%) of pts had non-measurable disease by RECIST 1.1. PD by any response criterion was associated with an at least 2.5-fold increased risk of death and was highest for PD versus CR/PR by aPERCIST (HR 11.4) on univariable regression. Stratified by castration status, a similar pattern was observed. PD by any criterion as associated with significantly shortened OS across overall and subgroup analyses. PR/CR by aPERCIST identified pts with lower risk of death and longer OS as compared to patients with PD or SD. Conclusion: 68Ga-PSMA11 PET-based response criteria (PPP, aPERCIST, aPCWG3) have high prognostic utility in men with metastatic PC undergoing taxane-based chemotherapy. PPP is simple to use, identified most patients with PD and showed best prognostic utility regarding OS. PR/CR by aPERCIST identifies a subgroup of responders (PR/CR) showing better outcomes than patients with PD or SD. Future studies are warranted to amend the current paradigm relying on mere differentiation of PD versus non-PD in metastatic PC and to identify true treatment responders by imaging criteria.
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Pretherapeutic Comparative Dosimetry of 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T in Patients with Metastatic Castration-Resistant Prostate Cancer. J Nucl Med 2022; 63:833-839. [PMID: 34531260 PMCID: PMC9157737 DOI: 10.2967/jnumed.121.262671] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/26/2021] [Indexed: 11/16/2022] Open
Abstract
Radiohybrid prostate-specific membrane antigen (rhPSMA) ligands allow for labeling with 18F and radiometals for endoradiotherapy. rhPSMA-7.3 has been designated as a lead compound with promising preclinical data for 177Lu-rhPSMA-7.3, which has shown higher tumor uptake than 177Lu-PSMA I&T. In this retrospective analysis, we compared pretherapeutic clinical dosimetry data of both PSMA ligands. Methods: Six patients with metastatic castration-resistant prostate cancer underwent both 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T pretherapeutic dosimetry. Whole-body scintigraphy was performed at 1 h, 4 h, 24 h, 48 h, and 7 d after injection. Regions of interest covering the whole body, organs, bone marrow, and tumor lesions were drawn for each patient. Absorbed doses for individual patients and pretherapeutic applications were calculated using OLINDA/EXM. To facilitate the comparison of both ligands, we introduced the therapeutic index (TI), defined as the ratio of mean pretherapeutic doses to tumor lesions over relevant organs at risk. Results: Mean whole-body pretherapeutic effective doses for 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T were 0.12 ± 0.07 and 0.05 ± 0.03 Sv/GBq, respectively. Mean absorbed organ doses for 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T were, for example, 1.65 ± 0.28 and 0.73 ± 0.18 Gy/GBq for the kidneys, 0.19 ± 0.09 and 0.07 ± 0.03 Gy/GBq for the liver, 2.35 ± 0.78 and 0.80 ± 0.41 Gy/GBq for the parotid gland, and 0.67 ± 0.62 and 0.30 ± 0.27 Gy/GBq for the bone marrow, respectively. Tumor lesions received mean absorbed doses of 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T of 6.44 ± 6.44 and 2.64 ± 2.24 Gy/GBq, respectively. The mean TIs for the kidneys were 3.7 ± 2.2 and 3.6 ± 2.2 for 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T, respectively, and those for the bone marrow were 15.2 ± 10.2 and 15.1 ± 10.2 for 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T, respectively. Conclusion: Pretherapeutic clinical dosimetry confirmed preclinical results of mean absorbed doses for tumors that were 2-3 times higher for 177Lu-rhPSMA-7.3 than for 177Lu-PSMA I&T. Absorbed doses to normal organs also tended to be higher for 177Lu-rhPSMA-7.3, resulting overall in similar average TIs for both radiopharmaceuticals with considerable interpatient variability. 177Lu-rhPSMA-7.3 has promise for a therapeutic efficacy similar to that of 177Lu-PSMA I&T at smaller amounts of injected activity, simplifying radiation safety measurements (especially for large patient numbers or dose escalation regimens).
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Narrative review: prostate-specific membrane antigen-radioligand therapy in metastatic castration-resistant prostate cancer. Transl Androl Urol 2021; 10:3963-3971. [PMID: 34804839 PMCID: PMC8575563 DOI: 10.21037/tau-20-1135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/15/2020] [Indexed: 12/25/2022] Open
Abstract
Radioactive-labelled ligands targeting the prostate-specific membrane antigen (PSMA), a transmembrane protein overexpressed in prostate cancer (PC), have shown promising activity in treatment of metastatic castration-resistant prostate cancer (mCRPC). PSMA-617 and PSMA-I&T (imaging and therapy), both labeled to the beta-emitter lutetium-177 (Lu177), are most frequently used in clinical routine and have shown a favorable side-effect profile. Common side effects are transient xerostomia. Severe side effects, e.g., treatment-associated myelosuppression, are rare. Currently treatment with Lu177-PSMA outside clinical trials is available for compassionate use for patients who exhausted conventional therapies. Previous retro- and prospective studies reported promising results with ≥50% PSA declines observed in at least one third of patients. Retrospective data suggests worse biochemical response in patients with visceral metastases. Preliminary data from the randomized phase II (TheraP) trial showed an improved biochemical response rate of Lu177-PSMA as compared to cabazitaxel in patients progressing after docetaxel. Following these promising data, the results of the randomized, prospective phase III VISION study are eagerly anticipated. A major challenge remains resistance to radioligand therapy with Lu177-PSMA. As an alternative, a PSMA-ligand labeled to the alpha-emitter Actinium-225 (Ac-225) may be offered to patients, which shows promising activity in patients developing progression under Lu177-PSMA at the cost of higher toxicity. Mostly permanent xerostomia is a relevant side effect resulting in treatment discontinuation in up to a quarter of patients. This review summarizes the literature on activity and toxicity of PSMA-targeted radioligand therapy in mCRPC.
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Comparative Preclinical Biodistribution, Dosimetry, and Endoradiotherapy in Metastatic Castration-Resistant Prostate Cancer Using 19F/ 177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T. J Nucl Med 2021; 62:1106-1111. [PMID: 33443072 DOI: 10.2967/jnumed.120.254516] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 12/04/2020] [Indexed: 12/29/2022] Open
Abstract
Radiohybrid prostate-specific membrane antigen (rhPSMA) ligands are applicable as radiochemical twins for both diagnostic PET imaging and endoradiotherapy. On the basis of preliminary data as a diagnostic ligand, the isomer rhPSMA-7.3 is a promising candidate for potential endoradiotherapy. The aim of this preclinical evaluation was to assess the biodistribution, dosimetry, and therapeutic efficacy of 19F/177Lu-rhPSMA-7.3 in comparison to the established therapeutic agent 177Lu-PSMA I&T (imaging and therapy). Methods: The biodistribution of 19F/177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T was determined in LNCaP tumor-bearing severe combined immunodeficiency (SCID) mice after sacrifice at defined time points up to 7 d (n = 5). Organs and tumors were dissected, percentage injected dose per gram (%ID/g) was determined, and dosimetry was calculated using OLINDA/EXM, version 1.0. The therapeutic efficacy of a single 30-MBq dose of 19F/177Lu-rhPSMA-7.3 (n = 7) was compared with that of 177Lu-PSMA I&T in treatment groups (n = 7) and control groups (n = 6-7) using C4-2 tumor-bearing SCID mice by evaluating tumor growth and survival over 6 wk after treatment. Results: The biodistribution of 19F/177Lu-rhPSMA-7.3 revealed fast blood clearance (0.63 %ID/g at 1 h after injection), and the highest activity uptake was in the spleen and kidneys, particularly in the first hour (33.25 %ID/g and 207.6 %ID/g, respectively, at 1 h after injection), indicating a renal excretion pathway. Compared with 177Lu-PSMA I&T, 19F/177Lu-rhPSMA-7.3 exhibited an initial (1 h) 2.6-fold higher tumor uptake in LNCaP xenografts and a longer retention (4.5 %ID/g vs. 0.9 %ID/g at 168 h). The tumor dose of 19F/177Lu-rhPSMA-7.3 was substantially higher (e.g., 7.47 vs. 1.96 µGy/MBq at 200 mm3) than that of 177Lu-PSMA I&T. In most organs, absorbed doses were higher for 177Lu-PSMA I&T. A significantly greater tumor size reduction was shown for a single dose of 19F/177Lu-rhPSMA-7.3 than for 177Lu-PSMA I&T at the end of the experiment (P = 0.0167). At the predefined termination of the experiment at 6 wk, 7 of 7 and 3 of 7 mice were still alive in the 19F/177Lu-rhPSMA-7.3 and 177Lu-PSMA I&T groups, respectively, compared with the respective control groups, with 0 of 7 and 0 of 6 mice. Conclusion: Compared with 177Lu-PSMA I&T, 19F/177Lu-rhPSMA-7.3 can be considered a suitable candidate for clinical translation because it has similar clearance kinetics and a similar radiation dose to healthy organs but superior tumor uptake and retention. Preliminary treatment experiments showed a favorable antitumor response.
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Metabolic Response of Pancreatic Carcinoma Cells under Treatment with Dichloroacetate. Metabolites 2021; 11:metabo11060350. [PMID: 34070873 PMCID: PMC8228235 DOI: 10.3390/metabo11060350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/21/2021] [Accepted: 05/27/2021] [Indexed: 11/16/2022] Open
Abstract
In modern oncology, the analysis and evaluation of treatment response are still challenging. Hence, we used a 13C-guided approach to study the impacts of the small molecule dichloroacetate (DCA) upon the metabolic response of pancreatic cancer cells. Two different oncogenic PI3K-driven pancreatic cancer cell lines, 9580 and 10,158, respectively, were treated with 75 mM DCA for 18 h. In the presence of [U-13C6]glucose, the effects of DCA treatment in the core carbon metabolism were analyzed in these cells using gas chromatography-mass spectrometry (GC/MS). 13C-enrichments and isotopologue profiles of key amino acids revealed considerable effects of the DCA treatment upon glucose metabolism. The DCA treatment of the two pancreatic cell lines resulted in a significantly decreased incorporation of [U-13C6]glucose into the amino acids alanine, aspartate, glutamate, glycine, proline and serine in treated, but not in untreated, cancer cells. For both cell lines, the data indicated some activation of pyruvate dehydrogenase with increased carbon flux via the TCA cycle, but also massive inhibition of glycolytic flux and amino acid biosynthesis presumably by inhibition of the PI3K/Akt/mTORC axis. Together, it appears worthwhile to study the early treatment response in DCA-guided or accompanied cancer therapy in more detail, since it could open new avenues for improved diagnosis and therapeutic protocols of cancer.
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Diverse metabolic response of cancer cells treated with a 213Bi-anti-EGFR-immunoconjugate. Sci Rep 2021; 11:6227. [PMID: 33737524 PMCID: PMC7973706 DOI: 10.1038/s41598-021-84421-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/15/2021] [Indexed: 12/14/2022] Open
Abstract
Evaluation of treatment response is among the major challenges in modern oncology. We herein used a monoclonal antibody targeting the EGF receptor (EGFR) labelled with the alpha emitter 213Bi (213Bi-anti-EGFR-MAb). EJ28Luc (bladder) and LN18 (glioma) cancer cells, both overexpressing EGFR, were incubated for 3 h with the radioimmunoconjugate. To assess the responses in the core carbon metabolism upon this treatment, these cancer cell lines were subsequently cultivated for 18 h in the presence of [U-13C6]glucose. 13C-enrichment and isotopologue profiles of key amino acids were monitored by gas chromatography–mass spectrometry (GC/MS), in order to monitor the impacts of the radionuclide-treatment upon glucose metabolism. In comparison to untreated controls, treatment of EJ28Luc cells with 213Bi-anti-EGFR-MAb resulted in a significantly decreased incorporation of 13C from [U-13C6]glucose into alanine, aspartate, glutamate, glycine, proline and serine. In sharp contrast, the same amino acids did not display less 13C-enrichments during treatment of the LN18 cells. The data indicate early treatment response of the bladder cancer cells, but not of the glioma cells though cell lines were killed following 213Bi-anti-EGFR-MAb treatment. The pilot study shows that the 13C-labelling approach is a valid tool to assess the responsiveness of cancer cells upon radionuclide-treatment in considerable metabolic detail.
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Differentiation of acute myeloid leukemia (AML) cells with ATRA reduces 18F-FDG uptake and increases sensitivity towards ABT-737-induced apoptosis. Leuk Lymphoma 2020; 62:630-639. [PMID: 33140666 DOI: 10.1080/10428194.2020.1839648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Acute myeloid leukemia (AML) is a malignant disease of the bone marrow, comprising various subtypes. We have investigated seven different AML cell lines that showed different sensitivities toward the inducer of apoptosis ABT-737, with IC50 concentrations ranging from 9.9 nM to 1.8 µM. Besides, the AML cell lines revealed distinct differences in 18F-FDG uptake ranging from 4.1 to 11.0%. Moreover, the Pearson coefficient (0.363) suggests a moderate correlation between 18F-FDG uptake and the IC50 values of ABT-737. Differentiation of the AML cell lines NB-4 and AML-193 with all-trans-retinoic-acid (ATRA) induced a significant increase in sensitivity towards ABT-737 along with a reduced uptake of 18F-FDG. Therefore, 18F-FDG uptake could be predictive on sensitivity to treatment with ABT-737. Furthermore, because differentiation treatment of AML cells using ATRA reduced 18F-FDG uptake and increased sensitivity towards ABT-737, a combined treatment regimen with ATRA and ABT-737 might be a promising therapeutic option in the future.
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Impact of 18F-FDG-PET/CT on the identification of regional lymph node metastases and delineation of the primary tumor in esophageal squamous cell carcinoma patients. Strahlenther Onkol 2020; 196:787-794. [PMID: 32430661 PMCID: PMC7449992 DOI: 10.1007/s00066-020-01630-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 04/28/2020] [Indexed: 12/27/2022]
Abstract
Purpose In patients undergoing chemoradiation for esophageal squamous cell carcinoma (ESCC), the extent of elective nodal irradiation (ENI) is still discussed controversially. This study aimed to analyze patterns of lymph node metastases and their correlation with the primary tumor using 18F‑fludeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans. Methods 102 ESCC patients with pre-treatment FDG-PET/CT scans were evaluated retrospectively. After exclusion of patients with low FDG uptake and patients without FDG-PET-positive lymph node metastases (LNM), 76 patients were included in the final analysis. All LNM were assigned to 16 pre-defined anatomical regions and classified according to their position relative to the primary tumor (above, at the same height, or below the primary tumor). In addition, the longitudinal distance to the primary tumor was measured for all LNM above or below the primary tumor. The craniocaudal extent (i.e., length) of the primary tumor was measured using FDG-PET imaging (LPET) and also based on all other available clinical and imaging data (endoscopy, computed tomography, biopsy results) except FDG-PET (LCT/EUS). Results Significantly more LNM were identified with 18F‑FDG-PET/CT (177 LNM) compared to CT alone (131 LNM, p < 0.001). The most common sites of LNM were paraesophageal (63% of patients, 37% of LNM) and paratracheal (33% of patients, 20% of LNM), while less than 5% of patients had supraclavicular, subaortic, diaphragmatic, or hilar LNM. With regard to the primary tumor, 51% of LNM were at the same height, while 25% and 24% of lymph node metastases were above and below the primary tumor, respectively. For thirty-three LNM (19%), the distance to the primary tumor was larger than 4 cm. No significant difference was seen between LCT/EUS (median 6 cm) and LPET (median 6 cm, p = 0.846) Conclusion 18F‑FDG-PET can help to identify subclinical lymph node metastases which are located outside of recommended radiation fields. PET-based involved-field irradiation might be the ideal compromise between small treatment volumes and decreasing the risk of undertreatment of subclinical metastatic lymph nodes and should be further evaluated.
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Safety and Efficacy of Ac-225-PSMA-617 in mCRPC after Failure of Lu-177-PSMA. J Med Imaging Radiat Sci 2019. [DOI: 10.1016/j.jmir.2019.11.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Safety and efficacy of Ac-225-PSMA-617 in metastatic castration resistant prostate cancer (mCRPC) after failure of Lu-177-PSMA. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz248.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Assessment of 213Bi-anti-EGFR MAb treatment efficacy in malignant cancer cells with [1- 13C]pyruvate and [ 18F]FDG. Sci Rep 2019; 9:8294. [PMID: 31165773 PMCID: PMC6549183 DOI: 10.1038/s41598-019-44484-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 05/13/2019] [Indexed: 12/02/2022] Open
Abstract
Evaluation of response to therapy is among the key objectives of oncology. A new method to evaluate this response includes magnetic resonance spectroscopy (MRS) with hyperpolarized 13C-labelled metabolites, which holds promise to provide new insights in terms of both therapeutic efficacy and tumor cell metabolism. Human EJ28Luc urothelial carcinoma and LN18 glioma cells were treated with lethal activity concentrations of a 213Bi-anti-EGFR immunoconjugate. Treatment efficacy was controlled via analysis of DNA double-strand breaks (immunofluorescence γH2AX staining) and clonogenic survival of cells. To investigate changes in metabolism of treated cells vs controls we analyzed conversion of hyperpolarized [1-13C]pyruvate to [1-13C]lactate via MRS as well as viability of cells, lactate formation and lactate dehydrogenase activity in the cellular supernatants and [18F]FDG uptake in treated cells vs controls, respectively. Treatment of malignant cancer cells with 213Bi-anti-EGFR-MAb induced intense DNA double-strand breaks, resulting in cell death as monitored via clonogenic survival. Moreover, treatment of EJ28Luc bladder cancer cells resulted in decreased cell viability, [18F]FDG-uptake and an increased lactate export. In both EJ28Luc and LN18 carcinoma cells treatment with 213Bi-anti-EGFR-MAb triggered a significant increase in lactate/pyruvate ratios, as measured with hyperpolarized [1-13C]pyruvate. Treatment with 213Bi-anti-EGFR-MAb resulted in an effective induction of cell death in EJ28Luc and LN18 cells. Lactate/pyruvate ratios of hyperpolarized [1-13C]pyruvate proved to detect early treatment response effects, holding promise for future clinical applications in early therapy monitoring.
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Simultaneous characterization of tumor cellularity and the Warburg effect with PET, MRI and hyperpolarized 13C-MRSI. Am J Cancer Res 2018; 8:4765-4780. [PMID: 30279736 PMCID: PMC6160766 DOI: 10.7150/thno.25162] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 06/26/2018] [Indexed: 02/07/2023] Open
Abstract
Modern oncology aims at patient-specific therapy approaches, which triggered the development of biomedical imaging techniques to synergistically address tumor biology at the cellular and molecular level. PET/MR is a new hybrid modality that allows acquisition of high-resolution anatomic images and quantification of functional and metabolic information at the same time. Key steps of the Warburg effect-one of the hallmarks of tumors-can be measured non-invasively with this emerging technique. The aim of this study was to quantify and compare simultaneously imaged augmented glucose uptake and LDH activity in a subcutaneous breast cancer model in rats (MAT-B-III) and to study the effect of varying tumor cellularity on image-derived metabolic information. Methods: For this purpose, we established and validated a multimodal imaging workflow for a clinical PET/MR system including proton magnetic resonance (MR) imaging to acquire accurate morphologic information and diffusion-weighted imaging (DWI) to address tumor cellularity. Metabolic data were measured with dynamic [18F]FDG-PET and hyperpolarized (HP) 13C-pyruvate MR spectroscopic imaging (MRSI). We applied our workflow in a longitudinal study and analyzed the effect of growth dependent variations of cellular density on glycolytic parameters. Results: Tumors of similar cellularity with similar apparent diffusion coefficients (ADC) showed a significant positive correlation of FDG uptake and pyruvate-to-lactate exchange. Longitudinal DWI data indicated a decreasing tumor cellularity with tumor growth, while ADCs exhibited a significant inverse correlation with PET standard uptake values (SUV). Similar but not significant trends were observed with HP-13C-MRSI, but we found that partial volume effects and point spread function artifacts are major confounders for the quantification of 13C-data when the spatial resolution is limited and major blood vessels are close to the tumor. Nevertheless, analysis of longitudinal data with varying tumor cellularity further detected a positive correlation between quantitative PET and 13C-data. Conclusions: Our workflow allows the quantification of simultaneously acquired PET, MRSI and DWI data in rodents on a clinical PET/MR scanner. The correlations and findings suggest that a major portion of consumed glucose is metabolized by aerobic glycolysis in the investigated tumor model. Furthermore, we conclude that variations in cell density affect PET and 13C-data in a similar manner and correlations of longitudinal metabolic data appear to reflect both biochemical processes and tumor cellularity.
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Treatment of carcinoma in situ of the urinary bladder with an alpha-emitter immunoconjugate targeting the epidermal growth factor receptor: a pilot study. Eur J Nucl Med Mol Imaging 2018; 45:1364-1371. [DOI: 10.1007/s00259-018-4003-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/23/2018] [Indexed: 02/03/2023]
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Hyperkalemia in patients treated with endoradiotherapy combined with amino acid infusion is associated with severe metabolic acidosis. EJNMMI Res 2018; 8:17. [PMID: 29488080 PMCID: PMC5829280 DOI: 10.1186/s13550-018-0370-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 02/19/2018] [Indexed: 01/08/2023] Open
Abstract
Background Amino acid co-infusion for renal protection in endoradiotherapy (ERT) applied as prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) or peptide receptor radionuclide therapy (PRRT) has been shown to cause severe hyperkalemia. The pathophysiology behind the rapid development of hyperkalemia is not well understood. We hypothesized that the hyperkalemia should be associated with metabolic acidosis. Results Twenty-two patients underwent ERT. Prior to the first cycle, excretory kidney function was assessed by mercapto-acetyltriglycine (MAG-3) renal scintigraphy, serum biochemistry, and calculated glomerular filtration rate (eGFR). All patients received co-infusion of the cationic amino acids L-arginine and L-lysine for nephroprotection. Clinical symptoms, electrolytes, and acid-base status were evaluated at baseline and after 4 h. No patient developed any clinically relevant side effects. At baseline, acid base status and electrolytes were normal in all patients. Excretory kidney function was normal or only mildly impaired in all except two patients with stage 3 renal insufficiency. All patients developed hyperkalemia. Base excess and HCO3− were significantly lower after 4 h. In parallel, mean pH dropped from 7.36 to 7.29. There was a weak association between calculated (r = − 0.21) as well as MAG-3-derived GFR (r = − 0.32) and the rise in potassium after 4 h. Conclusion Amino acid co-infusion during ERT leads to severe metabolic acidosis which induces hyperkalemia by potassium hydrogen exchange. This novel finding implies that commercially available bicarbonate solutions might be an easy therapeutic option to correct metabolic acidosis rapidly. Electronic supplementary material The online version of this article (10.1186/s13550-018-0370-z) contains supplementary material, which is available to authorized users.
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MTOR inhibitor-based combination therapies for pancreatic cancer. Br J Cancer 2018; 118:366-377. [PMID: 29384525 PMCID: PMC5808033 DOI: 10.1038/bjc.2017.421] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 10/25/2017] [Accepted: 10/26/2017] [Indexed: 12/13/2022] Open
Abstract
Background: Although the mechanistic target of rapamycin (MTOR) kinase, included in the mTORC1 and mTORC2 signalling hubs, has been demonstrated to be active in a significant fraction of patients with pancreatic ductal adenocarcinoma (PDAC), the value of the kinase as a therapeutic target needs further clarification. Methods: We used Mtor floxed mice to analyse the function of the kinase in context of the pancreas at the genetic level. Using a dual-recombinase system, which is based on the flippase-FRT (Flp-FRT) and Cre-loxP recombination technologies, we generated a novel cellular model, allowing the genetic analysis of MTOR functions in tumour maintenance. Cross-species validation and pharmacological intervention studies were used to recapitulate genetic data in human models, including primary human 3D PDAC cultures. Results: Genetic deletion of the Mtor gene in the pancreas results in exocrine and endocrine insufficiency. In established murine PDAC cells, MTOR is linked to metabolic pathways and maintains the glucose uptake and growth. Importantly, blocking MTOR genetically as well as pharmacologically results in adaptive rewiring of oncogenic signalling with activation of canonical extracellular signal-regulated kinase and phosphoinositide 3-kinase-AKT pathways. We provide evidence that interfering with such adaptive signalling in murine and human PDAC models is important in a subgroup. Conclusions: Our data suggest developing dual MTORC1/TORC2 inhibitor-based therapies for subtype-specific intervention.
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Front Cover: Deuteration of Hyperpolarized 13
C-Labeled Zymonic Acid Enables Sensitivity-Enhanced Dynamic MRI of pH (ChemPhysChem 18/2017). Chemphyschem 2017. [DOI: 10.1002/cphc.201700957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Deuteration of Hyperpolarized 13
C-Labeled Zymonic Acid Enables Sensitivity-Enhanced Dynamic MRI of pH. Chemphyschem 2017. [DOI: 10.1002/cphc.201700956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Hyperpolarized 13C Diffusion MRS of Co-Polarized Pyruvate and Fumarate to Measure Lactate Export and Necrosis. J Cancer 2017; 8:3078-3085. [PMID: 28928899 PMCID: PMC5604459 DOI: 10.7150/jca.20250] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/04/2017] [Indexed: 02/06/2023] Open
Abstract
Background: Non-invasive tumor characterization and monitoring are among the key goals of medical imaging. Using hyperpolarized 13C-labelled metabolic probes fast metabolic pathways can be probed in real-time, providing new opportunities for tumor characterization. In this in vitro study, we investigated whether measurement of apparent diffusion coefficient (ADC) measurements and magnetic resonance spectroscopy (MRS) of co-polarized 13C-labeled pyruvic acid and fumaric acid can non-invasively detect both necrosis and changes in lactate export, which are parameters indicative of tumor aggressiveness. Methods:13C-labeled pyruvic acid and fumaric acid were co-polarized in a preclinical hyperpolarizer and the dissolved compounds were added to prepared samples of 8932 pancreatic cancer and MCF-7 breast carcinoma cells. Extracellular lactate concentrations and cell viability were measured in separate assays. Results: The mean ratios of the ADC values of lactate and pyruvate (ADClac/ADCpyr) between MCF-7 (0.533 ± 0.015, n = 3) and 8932 pancreatic cancer cells (0.744 ± 0.064, n = 3) showed a statistically significant difference (p = 0.048). 8932 cells had higher extracellular lactate concentrations in the extracellular medium (22.97 ± 2.53 ng/µl) compared with MCF-7 cells (7.52 ± 0.59 ng/µl; p < 0.001). Fumarate-to-malate conversion was only detectable in necrotic cells, thereby allowing clear differentiation between necrotic and viable cells. Conclusion: We provide evidence that MRS of hyperpolarized 13C-labelled pyruvic acid and fumaric acid, with their respective conversions to lactate and malate, are useful for characterization of necrosis and lactate efflux in tumor cells.
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Deuteration of Hyperpolarized 13
C-Labeled Zymonic Acid Enables Sensitivity-Enhanced Dynamic MRI of pH. Chemphyschem 2017; 18:2422-2425. [DOI: 10.1002/cphc.201700779] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Indexed: 01/15/2023]
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Imaging of pH in vivo using hyperpolarized 13C-labelled zymonic acid. Nat Commun 2017; 8:15126. [PMID: 28492229 PMCID: PMC5482723 DOI: 10.1038/ncomms15126] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 03/02/2017] [Indexed: 01/09/2023] Open
Abstract
Natural pH regulatory mechanisms can be overruled during several pathologies such as cancer, inflammation and ischaemia, leading to local pH changes in the human body. Here we demonstrate that 13C-labelled zymonic acid (ZA) can be used as hyperpolarized magnetic resonance pH imaging sensor. ZA is synthesized from [1-13C]pyruvic acid and its 13C resonance frequencies shift up to 3.0 p.p.m. per pH unit in the physiological pH range. The long lifetime of the hyperpolarized signal enhancement enables monitoring of pH, independent of concentration, temperature, ionic strength and protein concentration. We show in vivo pH maps within rat kidneys and subcutaneously inoculated tumours derived from a mammary adenocarcinoma cell line and characterize ZA as non-toxic compound predominantly present in the extracellular space. We suggest that ZA represents a reliable and non-invasive extracellular imaging sensor to localize and quantify pH, with the potential to improve understanding, diagnosis and therapy of diseases characterized by aberrant acid-base balance. Local pH alterations can be manifestations of pathologies such as cancer, inflammation and ischaemia. Here Düwel et al. show hyperpolarized 13C-labelled zymonic acid can be used as a non-invasive probe to map and measure pH in vivo, suggesting it as a candidate for clinical imaging and a diagnostic tool.
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Abstract
In the past decades, new methods for tumor staging, restaging, treatment response monitoring, and recurrence detection of a variety of cancers have emerged in conjunction with the state-of-the-art positron emission tomography with 18F-fluorodeoxyglucose ([18F]-FDG PET). 13C magnetic resonance spectroscopic imaging (13CMRSI) is a minimally invasive imaging method that enables the monitoring of metabolism in vivo and in real time. As with any other method based on 13C nuclear magnetic resonance (NMR), it faces the challenge of low thermal polarization and a subsequent low signal-to-noise ratio due to the relatively low gyromagnetic ratio of 13C and its low natural abundance in biological samples. By overcoming these limitations, dynamic nuclear polarization (DNP) with subsequent sample dissolution has recently enabled commonly used NMR and magnetic resonance imaging (MRI) systems to measure, study, and image key metabolic pathways in various biological systems. A particularly interesting and promising molecule used in 13CMRSI is [1-13C]pyruvate, which, in the last ten years, has been widely used for in vitro, preclinical, and, more recently, clinical studies to investigate the cellular energy metabolism in cancer and other diseases. In this article, we outline the technique of dissolution DNP using a 3.35 T preclinical DNP hyperpolarizer and demonstrate its usage in in vitro studies. A similar protocol for hyperpolarization may be applied for the most part in in vivo studies as well. To do so, we used lactate dehydrogenase (LDH) and catalyzed the metabolic reaction of [1-13C]pyruvate to [1-13C]lactate in a prostate carcinoma cell line, PC3, in vitro using 13CMRSI.
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A Continuously Infused Microfluidic Radioassay System for the Characterization of Cellular Pharmacokinetics. J Nucl Med 2016; 57:1548-1555. [PMID: 27363838 DOI: 10.2967/jnumed.115.169151] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 02/08/2016] [Indexed: 12/14/2022] Open
Abstract
Measurement of cellular tracer uptake is widely applied to learn the physiologic status of cells and their interactions with imaging agents and pharmaceuticals. In-culture measurements have the advantage of less stress to cells. However, the tracer solution still needs to be loaded, unloaded, and purged from the cell culture during the measurements. Here, we propose a continuously infused microfluidic radioassay (CIMR) system for continuous in-culture measurement of cellular uptake. The system was tested to investigate the influence of the glucose concentration in cell culture media on 18F-FDG uptake kinetics. METHODS The CIMR system consists of a microfluidic chip integrated with a flow-control unit and a positron camera. Medium diluted with radioactive tracer flows through a cell chamber continuously at low speed. Positrons emitted from the cells and from tracer in the medium are measured with the positron camera. The human cell lines SkBr3 and Capan-1 were incubated with media of 3 different glucose concentrations and then measured with 18F-FDG on the CIMR system. In addition, a conventional uptake experiment was performed. The relative uptake ratios between different medium conditions were compared. A cellular 2-compartment model was applied to estimate the cellular pharmacokinetics on CIMR data. The estimated pharmacokinetic parameters were compared with expressions of glucose transporter-1 (GLUT1) and hexokinase-2 measured by quantitative real-time polymerase chain reaction. RESULTS The relative uptake ratios obtained from CIMR measurements correlated significantly with those from the conventional uptake experiments. The relative SDs of the relative uptake ratios obtained from the CIMR uptake experiments were significantly lower than those from the conventional uptake experiments. The fit of the cellular 2-compartment model to the 18F-FDG CIMR measurements was of high quality. For SkBr3, the estimated pharmacokinetic parameters k1 and k3 were consistent with the messenger RNA expression of GLUT1 and hexokinase-2: culturing with low glucose concentrations led to higher GLUT1 and hexokinase-2 expression as well as higher estimated k1 and k3 For Capan-1, the estimated k1 and k3 increased as the glucose concentration in the culture medium decreased, and this finding did not match the corresponding messenger RNA expression. CONCLUSION The CIMR system captures dynamic uptake within the cell culture and enables estimation of the cellular pharmacokinetics.
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Fractionated intravesical radioimmunotherapy with (213)Bi-anti-EGFR-MAb is effective without toxic side-effects in a nude mouse model of advanced human bladder carcinoma. Cancer Biol Ther 2015; 16:1526-34. [PMID: 26177233 DOI: 10.1080/15384047.2015.1071735] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Gold standard in therapy of superficial, non-muscle invasive urothelial tumors is transurethral resection followed by intravesical instillation therapies. However, relapse is commonly observed and therefore new therapeutic approaches are needed. Application of (213)Bi-immunoconjugates targeting EGFR had shown promising results in early tumor stages. The aim of this study was the evaluation of fractionated application of (213)Bi-anti-EGFR-MAb in advanced tumor stages in a nude mouse model. Luciferase-transfected EJ28 human bladder carcinoma cells were instilled intravesically into nude mice following electrocautery. Tumor development was monitored via bioluminescence imaging. One day after tumor detection mice were treated intravesically either 2 times with 0.93 MBq or 3 times with 0.46 MBq of (213)Bi-anti-EGFR-MAb. Therapeutic efficacy was evaluated via overall survival and toxicity toward normal urothelium by histopathological analysis. Mice without treatment and those treated with the native anti-EGFR-MAb showed mean survivals of 65.4 and 57.6 d, respectively. After fractionated treatment with 0.93 MBq of (213)Bi-anti-EGFR-MAb animals reached a mean survival of 141.5 d and 33% of the animals survived at least 268 d. Fractionated treatment with 0.46 MBq (213)Bi-anti-EGFR-MAb resulted in a mean survival of 131.8 d and 30% of the animals survived longer than 300 d. Significant differences were only observed between the control groups and the group treated twice with 0.93 MBq of (213)Bi-anti-EGFR-MAb. No toxic side-effects on the normal urothelium were observed even after treatment with 3.7 MBq of (213)Bi-anti-EGFR-MAb. The study demonstrates that the fractionated intravesical radioimmunotherapy with (213)Bi-anti-EGFR-MAb is a promising approach in advanced bladder carcinoma.
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Effects of topoisomerase inhibitors that induce DNA damage response on glucose metabolism and PI3K/Akt/mTOR signaling in multiple myeloma cells. Am J Cancer Res 2015; 5:1649-1664. [PMID: 26175935 PMCID: PMC4497433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/12/2015] [Indexed: 06/04/2023] Open
Abstract
Hallmarks of cancer cells comprise altered glucose metabolism (aerobic glycolysis) and differences in DNA damage response (DDR). Glucose transporters (GLUT), glycolytic enzymes such as hexokinase (HK) and metabolic pathways (e.g. PI3K/Akt/mTor) have been shown to be upregulated in multiple myeloma and other cancer cell lines. Here we have investigated the effects of clinically used inhibitors of topoisomerases, of DDR and of the PI3K/Akt/mTor pathway on glucose metabolism and on cell survival in multiple myeloma cells. The effects of DNA damaging topoisomerase inhibitors (doxorubicin, etoposide, topotecan), non-DNA damaging agents (bortezomib, vincristine) as well as of molecular inhibitors of DNA damage related kinases PIKKs (KU55933 [ATM], NU7026 [DNA-PKCs]) and PI3K/Akt/mTor signaling (BEZ235 [PI3K/mTor], MK-2206 [Akt]) were analyzed 24 hours after treatment of OPM-2 multiple myeloma cells. For this purpose we monitored [18F]-FDG uptake, cell viability using an ATP assay and expression of GLUT-1, hexokinase II (HKII), cleaved caspase-3 and cleaved PARP via Western-blotting. All topoisomerase inhibitors used could upregulate expression of GLUT-1 and HKII in OPM-2 cells, resulting in elevated [18F]-FDG uptake and promotion of cell survival. In contrast, bortezomib and vincristine induced a decline in [18F]-FDG uptake combined with early induction of apoptosis. Combination treatment with topoisomerase inhibitors and molecular inhibitors of PIKK and PI3K could reverse elevated [18F]-FDG uptake, as observed after application of topoisomerase inhibitors only, and aggravate induction of apoptosis. Thus, elevated glucose consumption in OPM-2 cells can be reversed by targeting both DDR and PI3K/Akt/mTOR signaling, thus providing a promising strategy in the treatment of cancer.
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DCA promotes progression of neuroblastoma tumors in nude mice. Am J Cancer Res 2015; 5:812-820. [PMID: 25973318 PMCID: PMC4396043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/05/2015] [Indexed: 06/04/2023] Open
Abstract
Even in the presence of oxygen most cancer cells convert glucose to lactate via pyruvate instead of performing oxidative phosphorylation (aerobic glycolysis-Warburg effect). Thus, it has been considered to shift pyruvate - the metabolite of aerobic glycolysis - to acetylCoA by activation of pyruvate dehydrogenase (PDH). AcetylCoA will then be metabolized by oxidative phosphorylation. Therefore, the purpose of this study was to shift tumor cells from aerobic glycolysis to oxidative phosphorylation using dichloroacetate (DCA), an inhibitor of PDH-kinase. The effects of DCA were assayed in vitro in Neuro-2a (murine neuroblastoma), Kelly and SK-N-SH (human neuroblastoma) as well as SkBr3 (human breast carcinoma) cell lines. The effects of DCA on tumor development were investigated in vivo using NMRI nu/nu mice bearing subcutaneous Neuro-2a xenografts. For that purpose animals were treated continuously with DCA in the drinking water. Tumor volumes were monitored using caliper measurements and via [18F]-FDG-positron emission tomography. DCA treatment increased viability/proliferation in Neuro-2a and SkBr3 cells, but did not cause significant alterations of PDH activity. However, no significant effects of DCA could be observed in Kelly and SK-N-SH cells. Accordingly, in mice bearing Neuro-2a xenografts, DCA significantly increased tumor proliferation compared to mock-treated mice. Thus, we could demonstrate that DCA - an indicated inhibitor of tumor growth - efficiently promotes tumor growth in Neuro-2a cells in vitro and in vivo.
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Five days of head-down-tilt bed rest induces noninflammatory shedding of L-selectin. J Appl Physiol (1985) 2013; 115:235-42. [DOI: 10.1152/japplphysiol.00381.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Head-down-tilt bed rest (HDTBR) is a popular model, simulating alterations of gravitation during space missions. The aim of this study was to obtain a better insight into the complexly orchestrated regulations of HDTBR-induced immunological responses, hypothesizing that artificial gravity can mitigate these HDTBR-related physiological effects. This crossover-designed 5 days of HDTBR study included three protocols with no, or daily 30 min of centrifugation or 6 × 5 min of centrifugation. Twelve healthy, male participants donated blood pre-HDTBR, post-HDTBR, and twice during HDTBR. Cellular immune changes were assessed either by enumerative and immune cell phenotyping assays or by functional testing of responses to either recall antigens or receptor-dependent activation by chemotactic agents N-formyl-methionyl-leucyl-phenylalanine (fMLP) and with TNF-α. The expression of the adhesion molecule L-selectin (CD62L) on the surface of granulocytes and its shedding into plasma samples were measured. In parallel, other humoral factor, such as interleukin-6 and interleukin-8, parameters of endothelial damage (glycocalyx) were determined. Hematocrit and hemoglobin were significantly increased during HDTBR. Although immune functional tests did not indicate a change in the immune performance, the expression of CD62L on resting granulocytes was significantly shed by 50% during HDTBR. Although the latter is normally associated to an activation of inflammatory innate immune responses and during interaction of granulocytes with the endothelium, CD62L shedding was, however, not related either to a systemic inflammatory alteration or to shedding of the endothelial glycocalyx during bed rest. This suggests a noninflammatory or “mechanical” shedding related to fluid shifts during head-down intervention and not to an acute inflammatory process.
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Lipoic acid inhibits cell proliferation of tumor cells in vitro and in vivo. Cancer Biol Ther 2012; 13:1425-35. [PMID: 22954700 DOI: 10.4161/cbt.22003] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cancer cells convert glucose preferentially to lactate even in the presence of oxygen (aerobic glycolysis-Warburg effect). New concepts in cancer treatment aim at inhibition of aerobic glycolysis. Pyruvate dehydrogenase converts pyruvate to acetylCoA thus preventing lactate formation. Therefore, the aim of this study was to evaluate compounds that could activate pyruvate dehydrogenase in cancer cells. We investigated the effects of (R)-(+)-α-lipoic acid (LPA) and dichloroacetate (DCA), possible activators of pyruvate dehydrogenase, on suppression of aerobic glycolysis and induction of cell death. The neuroblastoma cell lines Kelly, SK-N-SH, Neuro-2a and the breast cancer cell line SkBr3 were incubated with different concentrations (0.1-30 mM) of LPA and DCA. The effects of both compounds on cell viability/proliferation (WST-1 assay), [18F]-FDG uptake, lactate production and induction of apoptosis (flow cytometric detection of caspase-3) were evaluated. Furthermore, NMRI nu/nu mice that had been inoculated s.c. with SkBr3 cells were treated daily for four weeks with LPA (i.p, 18.5 mg/kg) starting at day 7 p.i.. Tumor development was measured with a sliding caliper and monitored via [18F]-FDG-PET. Residual tumors after therapy were examined histopathologically. These data suggests that LPA can reduce (1) cell viability/proliferation, (2) uptake of [18F]-FDG and (3) lactate production and increase apoptosis in all investigated cell lines. In contrast, DCA was almost ineffective. In the mouse xenograft model with s.c. SkBr3 cells, daily treatment with LPA retarded tumor progression. Therefore, LPA seems to be a promising compound for cancer treatment.
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