The genetic circuits that allow cancer cells to evade immune killing via epithelial mesenchymal plasticity remain poorly understood. Here, we showed that mesenchymal-like (Mes) KPC3 pancreatic... Show moreThe genetic circuits that allow cancer cells to evade immune killing via epithelial mesenchymal plasticity remain poorly understood. Here, we showed that mesenchymal-like (Mes) KPC3 pancreatic cancer cells were more resistant to cytotoxic T lymphocyte (CTL)–mediated killing than the parental epithelial–like (Epi) cells and used parallel genome-wide CRISPR screens to assess the molecular underpinnings of this difference. Core CTL-evasion genes (such as IFN-γ pathway components) were clearly evident in both types. Moreover, we identified and validated multiple Mes-specific regulators of cytotoxicity, such as Egfr and Mfge8. Both genes were significantly higher expressed in Mes cancer cells, and their depletion sensitized Mes cancer cells to CTL-mediated killing. Notably, Mes cancer cells secreted more Mfge8 to inhibit proliferation of CD8+ T cells and production of IFN-γ and TNFα. Clinically, increased Egfr and Mfge8 expression was correlated with a worse prognosis. Thus, Mes cancer cells use Egfr-mediated intrinsic and Mfge8-mediated extrinsic mechanisms to facilitate immune escape from CD8+ T cells. Show less
Rotteveel, L.; Kurakula, K.; Kooijman, E.J.M.; Schuit, R.C.; Verlaan, M.; Schreurs, M.; ... ; Windhorst, A.D. 2022
The transforming growth factor beta (TGF beta) pathway plays a complex role in cancer biology, being involved in both tumour suppression as well as promotion. Overactive TGF beta signalling has... Show moreThe transforming growth factor beta (TGF beta) pathway plays a complex role in cancer biology, being involved in both tumour suppression as well as promotion. Overactive TGF beta signalling has been linked to multiple diseases, including cancer, pulmonary arterial hypertension, and fibrosis. One of the key meditators within this pathway is the TGF beta type I receptor, also termed activin receptor-like kinase 5 (ALK5). ALK5 expression level is a key determinant of TGF beta signalling intensity and duration, and perturbation has been linked to diseases. A validated ALK5 positron emission tomography (PET) tracer creates an opportunity, therefore, to study its role in human diseases. To develop ALK5 PET tracers, two small molecule ALK5 kinase inhibitors were selected as lead compounds, which were labelled with carbon-11 and fluorine-18, respectively. [C-11]LR111 was synthesized with a yield of 17 +/- 6%, a molar activity of 126 +/- 79 GBq. mol(-1) and a purity of > 95% (n = 44). [18F]EW-7197 was synthesized with a yield of 10 +/- 5%, a molar activity of 183 & PLUSMN; 126 GBq. mol(-1) and a purity of > 95% (n = 11). Metabolic stability was evaluated in vivo in mice, showing 39 +/- 2% of intact [11C]LR111 and 21 +/- 2% of intact [F-18]EW-7197 in blood plasma at 45 min p.i. In vitro binding experiments were conducted in breast cancer MDAMB-231 and lung cancer A431 cell lines. In addition, both tracers were used for PET imaging in MDA-MB-231 xenograft models. Selective uptake of [F-18]EW-7197 and [C-11]LR111 was observed in MDA-MB-231 cells, in the MDA-MB-231 tumour xenografts in vivo and in the autoradiograms. As [C-11]LR111 and [F-18]EW-7197 showed selectivity of binding to ALK5 in vivo and in vitro. Both tracers are thereby valuable tools for the detection of ALK5 activity. Show less
Stadt, E.A. van de; Yaqub, M.; Lammertsma, A.A.; Poot, A.J.; Schuit, R.C.; Remmelzwaal, S.; ... ; Bahce, I. 2021
Objectives: Non-small cell lung cancer (NSCLC) tumors harboring common (exon19del, L858R) and uncommon (e.g. G719X, L861Q) activating epidermal growth factor receptor (EGFR) mutations are best... Show moreObjectives: Non-small cell lung cancer (NSCLC) tumors harboring common (exon19del, L858R) and uncommon (e.g. G719X, L861Q) activating epidermal growth factor receptor (EGFR) mutations are best treated with EGFR tyrosine kinase inhibitors (TKI) such as the first-generation EGFR TKI erlotinib, second-generation afatinib or third-generation osimertinib. However, identifying these patients through biopsy is not always possible. Therefore, our aim was to evaluate whether 18F-afatinib PET/CT could identify patients with common and uncommon EGFR mutations. Furthermore, we evaluated the relation between tumor 18F-afatinib uptake and response to afatinib therapy.Materials and methods: 18F-afatinib PET/CT was performed in 12 patients: 6 EGFR wild type (WT), 3 EGFR common and 3 EGFR uncommon mutations. Tumor uptake of 18F-afatinib was quantified using TBR_WB60-90 (tumor-to-whole blood activity ratio 60-90 min post-injection) for each tumor. Response was quantified per lesion using percentage of change (PC): [(response measurement (RM)?baseline measurement (BM))/BM]?100. Statistical analyses were performed using t-tests, correlation plots and sensitivity/specificity analysis.Results: Twenty-one tumors were identified. Injected dose was 348 ? 31 MBq. Group differences were significant between WT versus EGFR (common and uncommon) activating mutations (p = 0.03). There was no significant difference between EGFR common versus uncommon mutations (p = 0.94). A TBR_WB60-90 cut-off value of 6 showed the best relationship with response with a sensitivity of 70 %, a specificity of 100 % and a positive predictive value of 100 %.Conclusion: 18F-afatinib uptake was higher in tumors with EGFR mutations (common and uncommon) compared to WT. Furthermore, a TBR_WB60-90 cut-off of 6 was found to best predict response to therapy. 18F-afatinib PET/ CT could provide a means to identify EGFR mutation positive patients who benefit from afatinib therapy. Show less
The aim of this work was to quantify the uptake of F-18-BMS-986192, a programmed cell death ligand 1 (PD-L1) adnectin PET tracer, in patients with non-small cell lung cancer. To this end, plasma... Show moreThe aim of this work was to quantify the uptake of F-18-BMS-986192, a programmed cell death ligand 1 (PD-L1) adnectin PET tracer, in patients with non-small cell lung cancer. To this end, plasma input kinetic modeling of dynamic tumor uptake data with online arterial blood sampling was performed. In addition, the accuracy of simplified uptake metrics such as SUV was investigated. Methods: Data from a study with F-18-BMS-986192 in patients with advanced-stage non-small cell lung cancer eligible for nivolumab treatment were used if a dynamic scan was available and lesions were present in the field of view of the dynamic scan. After injection of F-18-BMS-986192, a 60-min dynamic PET/CT scan was started, followed by a 30-min whole-body PET/CT scan. Continuous arterial and discrete arterial and venous blood sampling were performed to determine a plasma input function. Tumor time-activity curves were fitted by several plasma input kinetic models. Simplified uptake parameters included tumor-to-blood ratio as well as several SUV measures. Results: Twenty-two tumors in 9 patients were analyzed. The arterial plasma input single-tissue reversible compartment model with fitted blood volume fraction seems to be the most preferred model as it best fitted 11 of 18 tumor time-activity curves. The distribution volume (V-T) ranged from 0.4 to 4.8 mL.cm(-3). Similar values were obtained with an image-derived input function. From the simplified measures, SUV normalized for body weight at 50 and 67 min after injection correlated best with V-T, with an R-2 of more than 0.9. Conclusion: A single-tissue reversible model can be used to quantify tumor uptake of the PD-L1 PET tracer F-18-BMS-986192. SUV at 60 min after injection, normalized for body weight, is an accurate simplified parameter for uptake assessment of baseline studies. To assess its predictive value for response evaluation during programmed cell death protein 1 or PD-L1 immune checkpoint inhibition, further validation of SUV against V-T based on an image-derived input function is recommended. Show less
Stadt, E.A. van de; Yaqub, M.; Lammertsma, A.A.; Poot, A.J.; Schober, P.R.; Schuit, R.C.; ... ; Hendrikse, N.H. 2020
Introduction: Only a subgroup of non-small cell lung cancer (NSCLC) patients benefit from treatment using epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) such as afatinib.... Show moreIntroduction: Only a subgroup of non-small cell lung cancer (NSCLC) patients benefit from treatment using epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) such as afatinib. Tumour uptake of [F-18]afatinib using positron emission tomography (PET) may identify those patients that respond to afatinib therapy. Therefore, the aim of this study was to find the optimal tracer kinetic model for quantification of [F-18]afatinib uptake in NSCLC tumours.Methods: [F-18]Afatinib PET scans were performed in 10 NSCLC patients. The first patient was scanned for the purpose of dosimetry. Subsequent patients underwent a 20-min dynamic [O-15]H2O PET scan (370 MBq) followed by a dynamic [F-18]afatinib PET scan (342 +/- 24 MBq) of 60 or 90 min. Using the Akaike information criterion (AIC), three pharmacokinetic plasma input models were evaluated with both metabolite-corrected sampler-based input and image-derived (IDIF) input functions in combination with discrete blood samples. Correlation analysis of arterial on-line sampling versus IDIF was performed. In addition, perfusion dependency and simplified measures were assessed.Results: Ten patients were included. The injected activity of [F-18]afatinib was 341 +/- 37 MBq. Fifteen tumours could be identified in the field of view of the scanner. Based on AIC, tumour kinetics were best described using an irreversible two-tissue compartment model and a metabolite-corrected sampler-based input function (Akaike 50%). Correlation of plasma-based input functions with metabolite-corrected IDIF was very strong (r(2)= 0.93). The preferred simplified uptake parameter was the tumour-to-blood ratio over the 60- to 90-min time interval (TBR60-90). Tumour uptake of [F-18]afatinib was independent of perfusion.Conclusion: The preferred pharmacokinetic model for quantifying [F-18]afatinib uptake in NSCLC tumours was the 2T3K_vb model. TBR(60-90)showed excellent correlation with this model and is the best candidate simplified method. Show less
Verbeek, J.; Eriksson, J.; Syvänen, S.; Huisman, M.; Schuit, R.C.; Molthoff, C.F.M.; ... ; Windhorst, A.D. 2018
-(4-methoxyphenyl)hydrazine-carbothioamide was described as a potential selective P-gp inhibitor that is not transported by P-gp. Therefore, the purpose of this study was to radiolabel two of its... Show more-(4-methoxyphenyl)hydrazine-carbothioamide was described as a potential selective P-gp inhibitor that is not transported by P-gp. Therefore, the purpose of this study was to radiolabel two of its analogues and to assess their potential for imaging P-gp expression using PET.\n across the blood-brain barrier was not altered by pre-treatment with the P-gp inhibitor tariquidar, and uptake was significantly lower in P-gp KO than in wild-type animals and indeed transported across the BBB or bound to P-gp in endothelial cells.\n appears to be a radiotracer that binds to P-gp, as showed in P-gp knock-out animals, but is not a substrate for P-gp.\nBackground\nResults\nConclusion Show less
Mansor, S.; Boellaard, R.; Huisman, M.C.; Berckel, B. van; Schuit, R.C.; Windhorst, A.D.; ... ; Velden, F. van 2016
