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Biodistribution analysis of 89Zr-labelled anti-Gal3 mAb in three different animal models.

Purpose:The innate tumor homing potential of mesenchymal stem cells (MSCs) has been used for a targeted delivery of the theranostic sodium iodide symporter (NIS) transgene into solid tumors. We have previously shown that external beam radiotherapy (EBRT) results in the enhanced recruitment of NIS-expressing MSCs into human hepatocellular carcinoma (HuH7). In parallel, the tumor-associated cytokine TGFB1 becomes strongly upregulated in HuH7 tumors in response to EBRT.Experimental Design:We therefore evaluated the effects of combining focused EBRT (5 Gy) with MSC-mediated systemic delivery of the theranostic NIS transgene under control of a synthetic TGFB1-inducible SMAD-responsive promoter (SMAD-NIS-MSCs) using 123I-scintigraphy followed by 131I therapy in CD1 nu/nu mice harboring subcutaneous human hepatocellular carcinoma (HuH7).Results:Following tumor irradiation and SMAD-NIS-MSC application, tumoral iodide uptake monitored in vivo by 123I-scintigraphy was enhanced as compared with nonirradiated tumors. Combination of EBRT and SMAD-NIS-MSC–mediated 131I therapy resulted in a significantly improved delay in tumor growth and prolonged survival in therapy mice as compared with the combined therapy using CMV-NIS-MSCs or to control groups receiving EBRT or saline only, or EBRT together with SMAD-NIS-MSCs and saline applications.Conclusions:MSC-based NIS-mediated 131I therapy after EBRT treatment dramatically enhanced therapeutic efficacy when a TGFB1-inducible SMAD-responsive promoter was used to drive NIS expression in adoptively applied MSCs. The remarkable therapeutic effect seen is thought to be linked in large part to the enhanced TGFB1 produced in this context, which leads to a highly selective and focused amplification of MSC-based NIS expression within the tumor milieu.

Radio-TLC Analysis and stability testing of TPP-PEG24-DFO[89Zr] and cmHsp70.1-DFO[89]

Supplementary Figure S2. Immunofluorescence staining of proliferating cells (Ki67) and blood vessels (CD31). Immunofluorescence analysis for Ki67 (green) and CD31 (red) showed no difference in proliferation as well as blood vessel density in resected tumors of mice treated with radiation and SMAD-NIS MSC followed by 131I treatment as compared to therapy mice receiving CMV-NIS-MSCs or irradiated tumors of mice injected with SMAD-NIS MSCs and NaCl or non-irradiated tumors receiving NaCl only (A-C). Slides of tumors were counterstained with Hoechst nuclear stain and one representative image is shown each (20Ã- magnification) (A).

The high prevalence of thyroid nodules in the adult population and the relatively low incidence of thyroid cancer make the preoperative identification of malignant lesions challenging. The β-galactoside–binding protein galectin-3 is widely expressed in well-differentiated thyroid carcinomas, but not in normal thyrocytes and benign thyroid nodules. This molecule offers a candidate biomarker to improve thyroid cancer diagnosis. Here we report the development of an immunoPET approach for noninvasive imaging of thyroid cancer. The method employs a 89Zr-labeled mAb to galectin-3, which shows high specificity and binding affinity in vitro. Reliable and specific immunoPET imaging was obtained of thyroid cancer in vivo in murine xenograft models of human thyroid cancer. Our findings provide a method to improve the clinical management of patients with thyroid nodules while reducing unnecessary surgery and social costs. Cancer Res; 76(12); 3583–92. ©2016 AACR.

In vivo stability of TPP-PEG24-DFO[89Zr] in blood, kidney, liver, 4T1 and CT26 tumors

Supplementary Figure S1. Cell viability after EW-7197 treatment. The viability of SMAD-NIS-MSCs was not affected by treatment with different concentrations of the selective TGFB signaling inhibitor EW-7197 with or without 10 ng/ml TGFB1 for 24 h as determined by MTT assay. Data are presented as percent of untreated controls from four independent experiments (means {plus minus} SEM).

Supplementary Data from Protein Expression Profiling in Esophageal Adenocarcinoma Patients Indicates Association of Heat-Shock Protein 27 Expression and Chemotherapy Response

Purpose: To identify pretherapeutic predictive biomarkers in tumor biopsies of patients with locally advanced esophageal adenocarcinomas treated with neoadjuvant chemotherapy, we used an explorative proteomic approach to correlate pretherapeutic protein expression profiles with tumor response to neoadjuvant chemotherapy.Experimental Design: Thirty-four patients with locally advanced esophageal adenocarcinomas who received neoadjuvant platin/5-fluorouracil–based chemotherapy before surgical resection were enrolled in this study. Response to chemotherapy was determined (a) by the amount of decline of [18F]fluorodeoxyglucose tumor uptake 2 weeks after the start of chemotherapy measured by positron emission tomography and (b) by histopathologic evaluation of tumor regression after surgical resection. Explorative quantitative and qualitative protein expression analysis was done through a quantitative differential protein expression analysis that used dual-isotope radioactive labeling of protein extracts. Selected identified biomarkers were validated by immunohistochemistry and quantitative real time reverse transcription-PCR.Results: Proteomic analysis revealed four cellular stress response–associated proteins [heat-shock protein (HSP) 27, HSP60, glucose-regulated protein (GRP) 94, GRP78] and a number of cytoskeletal proteins whose pretherapeutic abundance was significantly different (P < 0.001) between responders and nonresponders. Immunohistochemistry and gene expression analysis confirmed these data, showing a significant association between low HSP27 expression and nonresponse to neoadjuvant chemotherapy (P = 0.049 and P = 0.032, respectively).Conclusions: Albeit preliminary, our encouraging data suggest that protein expression profiling may distinguish cancers with a different response to chemotherapy. Our results suggest that response to chemotherapy may be related to a different activation of stress response and inflammatory biology in general. Moreover, the potential of HSPs and GRPs as biomarkers of chemotherapy response warrants further validation.

Synthesis, characterization and in vitro and in vivo stability testing of TPP-PEG24-DFO[89Zr] and histological analysis of a benign fibroblast hyperplasia

Supplementary Fig. S4. Tumor vascularization and necrosis in human HCC.

High precision in vivo PET/CT imaging of solid tumors improves diagnostic credibility and clinical outcome of patients. An epitope of the oligomerization domain of Hsp70 is exclusively exposed on the membrane of a large variety of tumor types, but not on normal cells, and thus provides a universal tumor-specific target. Here we developed a novel PET tracer TPP-PEG24-DFO[89Zr] based on the tumor cell–penetrating peptide probe TPP, which specifically recognizes membrane Hsp70 (mHsp70) on tumor cells. The implemented PEG24 moiety supported tracer stability and improved biodistribution characteristics in vivo. The Kd of the tracer ranged in the low nanomolar range (18.9 ± 11.3 nmol/L). Fluorescein isothiocyanate (FITC)-labeled derivatives TPP-[FITC] and TPP-PEG24-[FITC] revealed comparable and specific binding to mHsp70-positive 4T1, 4T1+, a derivative of the 4T1 cell line sorted for high Hsp70 expression, and CT26 tumor cells, but not to mHsp70-negative normal fibroblasts. The rapid internalization kinetics of mHsp70 into the cytosol and the favorable biodistribution of the peptide-based tracer TPP-PEG24-DFO[89Zr] in vivo enabled a tumor-specific accumulation with a high tumor-to-background contrast and renal body clearance. The tumor-specific enrichment of the tracer in 4T1+ (6.2 ± 1.1%ID/g), 4T1 (4.3 ± 0.7%ID/g), and CT26 (2.6 ± 0.6%ID/g) mouse tumors with very high, high, and intermediate mHsp70 densities, respectively, reflected mHsp70 expression profiles of the different tumor types, whereas benign mHsp70-negative fibroblastic hyperplasia showed no tracer accumulation (0.2 ± 0.03%ID/g). The ability of our chemically optimized peptide-based tracer TPP-PEG24-DFO[89Zr] to detect mHsp70 in vivo suggests its broad applicability in targeting and imaging with high specificity for any tumor type that exhibits surface expression of Hsp70.Significance: A novel peptide-based PET tracer against the oligomerization domain of Hsp70 has potential for universal tumor-specific imaging in vivo across many tumor type. Cancer Res; 78(21); 6268–81. ©2018 AACR.

Supplementary tables S1-3 and figure legends. Supplementary Table S1. Antibodies and antibody dilution used for immunohistochemical analyses. Supplementary Table S2. Characterization of human HCC Supplementary Table S3. Number of tumors per analyzed animal of DEN and McA model.

Biodistribution analysis of 89Zr-labelled anti-Gal3 mAb in FRO82-1 tumor bearing mice as selected model.

Histological section of benign fibroblat hyperplasia (A), H&E (B), and Hsp70 (C) immunohistochemical staining

Supplementary Fig. S3. aCGH analyses.

Supplementary Fig. S2. Macrophage and T-lymphocyte infiltration in DEN and McA animals.

Immunofluorescence analysis of CD31expression in murine TS/A tumours.

Description of additional methods and procedures used in the study.

Supplementary Fig. S1. Schematic of study design.

Supplementary Figure 1. Summary and survival of murine cohort used in the study. Supplementary Figure 2 Consort diagram of the patient distribution of surgical subcohort 1. Supplementary Figure 3. Consort diagram of the patient distribution of surgical subcohort 2. Supplementary Figure 4. Consort diagram of the patient distribution of surgical subcohort 3. Supplementary Figure 5. Schematic of relative tumor cell and stroma contribution in PDAChigh Supplementary Table 1. Statistics of the patients used in surgical subcohort 1. Supplementary Table 2. Statistics of the patients used in surgical subcohort 2. Supplementary Table 3. Statistics of the patients used in surgical subcohort 3. Supplementary Table 4. Results of a multivariable Cox regression model fit to the data of subcohort 2 that assess whether PDAC is associated with overall survival after adjustment for common predictors. Supplementary Table 5. The permutation test analysis revealing association between overall survival and lowest ADC stratified by each of the relevant categorical variables. Data used for analysis are derived from surgical subcohort 3.

In vitro characterization of TPP-PEG24-DFO[89Zr]. KD analysis (A), IC50 (B), internalization kinetics (C), short-term (D) and long-term (E) time-activity analysis

Purpose: Tumor heterogeneity is a hallmark of pancreatic ductal adenocarcinoma (PDAC). It determines tumor biology including tumor cellularity (i.e., amount of neoplastic cells and arrangement into clusters), which is related to the proliferative capacity and differentiation and the degree of desmoplasia among others. Given the close relation of tumor differentiation with differences in progression and therapy response or, e.g., the recently reported protective role of tumor stroma, we aimed at the noninvasive detection of PDAC groups, relevant for future personalized approaches. We hypothesized that histologic differences in PDAC tissue composition are detectable by the noninvasive diffusion weighted- (DW-) MRI-derived apparent diffusion coefficient (ADC) parameter.Experimental design: PDAC cellularity was quantified histologically and correlated with the ADC parameter and survival in genetically engineered mouse models and human patients.Results: Histologic analysis showed an inverse relationship of tumor cellularity and stroma content. Low tumor cellularity correlated with a significantly prolonged mean survival time (PDAClow = 21.93 months vs. PDACmed = 12.7 months; log-rank P < 0.001; HR = 2.23; CI, 1.41–3.53). Multivariate analysis using the Cox regression method confirmed tumor cellularity as an independent prognostic marker (P = 0.034; HR = 1.73; CI, 1.04–2.89). Tumor cellularity showed a strong negative correlation with the ADC parameter in murine (r = −0.84; CI, −0.90– −0.75) and human (r = −0.79; CI, −0.90 to −0.56) PDAC and high preoperative ADC values correlated with prolonged survival (ADChigh = 41.7 months; ADClow = 14.77 months; log rank, P = 0.040) in PDAC patients.Conclusions: This study identifies high tumor cellularity as a negative prognostic factor in PDAC and supports the ADC parameter for the noninvasive identification of PDAC groups. Clin Cancer Res; 23(6); 1461–70. ©2016 AACR.

Schematic representation of the synthesis of TPP-DFO, TPP-PEG24-DFO, TPP-PEG24-FITC

Epifluorescence measurements of TPP[Cy5.5] in 4T1 wild type and Hsp70 knock-out tumors

Immunohistochemical analysis of galectin-3 expression in normal tissues ex vivo.

Legends for Supplementary Figures S1-S2.

LC-MS trace and ESI-MS spectrum of TPP-DFO, Mal-PEG24-DFO, TPP-PEG24-DFO, TPP-PEG24-DFO-natZr, Mal-PEG24-FITC, and TPP-PEG24-FITC

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PDF file - 96K, FLT uptake is a sensitive measure for response to HSP90 inhibition in NPM-ALK overexpressing lymphoma cells in vitro

Supplementary Material and Figure Legends

Sensitive in vivo imaging technologies applicable to the clinical setting are still lacking for adoptive T-cell–based immunotherapies, an important gap to fill if mechanisms of tumor rejection or escape are to be understood. Here, we propose a highly sensitive imaging technology to track human TCR-transgenic T cells in vivo by directly targeting the murinized constant TCR beta domain (TCRmu) with a zirconium-89 (89Zr)-labeled anti–TCRmu-F(ab')2 fragment. Binding of the labeled or unlabeled F(ab')2 fragment did not impair functionality of transgenic T cells in vitro and in vivo. Using a murine xenograft model of human myeloid sarcoma, we monitored by Immuno-PET imaging human central memory T cells (TCM), which were transgenic for a myeloid peroxidase (MPO)–specific TCR. Diverse T-cell distribution patterns were detected by PET/CT imaging, depending on the tumor size and rejection phase. Results were confirmed by IHC and semiquantitative evaluation of T-cell infiltration within the tumor corresponding to the PET/CT images. Overall, these findings offer a preclinical proof of concept for an imaging approach that is readily tractable for clinical translation. Cancer Res; 76(14); 4113–23. ©2016 AACR.

Investigation of different imaging time points to track TCR-transduced TCM after injection of 89Zr-aTCRmu-F(ab')2

Differential distribution of 89Zr-aTCRmu-F(ab')2 signals within ML2-B7 tumors of mice injected with 2.5D6TCR-transgenic TCM

Investigation of dynamics of tumor rejection mediated by TCR2.5D6-transduced TCM to determine biologically critical imaging time points in an ML2-based myeloid sarcoma model

PDF file - 51K, Effect of everolimus on SUDHL-1 cells in vitro

Determination of different tumor rejection kinetics according to tumor size

Investigation of uptake by biodistribution and autoradiography as well as stability of 89Zr-aTCRmu-F(ab')2 within a clinically relevant ML2-based myeloid sarcoma model of adoptive T-cell transfer

PDF file - 96K, FLT uptake is a measure for nonresponse to HSP90 inhibition in NPM-ALK+ overexpressing lymphoma cells in vitro

Background Transpathology highlights the interpretation of the underlying physiology behind molecular imaging. However, it remains challenging due to the discrepancies between in vivo and in vitro measurements and difficulties of precise co-registration between trans-scaled images. This study aims to develop a multimodal intravital molecular imaging (MIMI) system as a tool for in vivo tumour transpathology investigation. Methods The proposed MIMI system integrates high-resolution positron imaging, magnetic resonance imaging (MRI) and microscopic imaging on a dorsal skin window chamber on an athymic nude rat. The window chamber frame was designed to be compatible with multimodal imaging and its fiducial markers were customized for precise physical alignment among modalities. The co-registration accuracy was evaluated based on phantoms with thin catheters. For proof of concept, tumour models of the human colorectal adenocarcinoma cell line HT-29 were imaged. The tissue within the window chamber was sectioned, fixed and haematoxylin–eosin (HE) stained for comparison with multimodal in vivo imaging. Results The final MIMI system had a maximum field of view (FOV) of 18 mm × 18 mm. Using the fiducial markers and the tubing phantom, the co-registration errors are 0.18 ± 0.27 mm between MRI and positron imaging, 0.19 ± 0.22 mm between positron imaging and microscopic imaging and 0.15 ± 0.27 mm between MRI and microscopic imaging. A pilot test demonstrated that the MIMI system provides an integrative visualization of the tumour anatomy, vasculatures and metabolism of the in vivo tumour microenvironment, which was consistent with ex vivo pathology. Conclusions The established multimodal intravital imaging system provided a co-registered in vivo platform for trans-scale and transparent investigation of the underlying pathology behind imaging, which has the potential to enhance the translation of molecular imaging.

Objective Despite the improved lesion detectability as the outcome of 18F-FDG PET/MR, small distant metastasis of pancreatic ductal adenocarcinoma (PDAC) often remains invisible. Our goal is to explore the potential of the joint radiomics analysis of PET and MRI imaging (PET-MRI) of primary tumors for predicting the risk of distant metastasis in patients with PDAC. Methods Nighty one PDAC patients with 18F-FDG PET and MRI imaging before the confirmation or exclusion of SDM were retrospectively investigated. Among them, 66 patients who received 18F-FDG PET/CT and multi-sequence MRI separately were included in the development of the radiomics model (development cohort), and 25 patients scanned with hybrid PET/MR were incorporated for independent verification (external test cohort). A radiomics signature was constructed using the selected PET-MRI radiomics features of primary PDAC tumors. Furthermore, a radiomics nomogram was developed by combining the radiomics signature and clinical indicators assisting in this way in the assessment of patients’ metastasis risk. Results In the development cohort, the radiomics nomogram had a better performance in predicting the risk of distant metastasis [area under the curve (AUC): 0.93, sensitivity:87.0%, specificity:85.0%] than this of the clinical model (AUC: 0.70, P 0.05; sensitivity: 65%, specificity: 100%). For the external test, the radiomics nomogram yielded an AUC of 0.85, a sensitivity of 78.6%, and a specificity of 90.9%, which was comparable to the development (P = 0.34). Conclusions The preliminary results confirmed the potential of PET MRI-based radiomics analysis in the robust and effective prediction of the risk of SDM for preoperative PDAC patients. The in-depth analysis of the primary tumor may offer complementary information and provide hints for cancer staging.

Our previous study has demonstrated the feasibility of noninvasive imaging of fibroblast activation protein (FAP)-expression after myocardial infarction (MI) in MI-territory in a rat model with 68Ga-FAPI-04-PET. In the current extended clinical case, we sought to delineate cardiac uptake of 68Ga-FAPI-04 in a patient after MI with clinical indication for the evidence of fibroblast activation. Carcinoma patients without cardiac disease underwent 68Ga-FAPI-04-PET/CT as control. The patient with one-vessel disease underwent dynamic 68Ga-FAPI-04-cardiac-PET/CMR for 60 minutes. Correlation of cardiac 68Ga-FAPI-04 uptake with clinical findings, ECG, echocardiography, coronary-arteriography and enhanced cardiac-MRI with T1 MOLLI and ECV mapping were performed. No uptake was found in normal myocardium and in mature scar. A focal intense 68Ga-FAPI-04 uptake with continuous wash-out in the infarct territory of coronary occlusion correlating with T1 and ECV mapping was observed. The uptake of 68Ga-FAPI-04 extends beyond the actual infarcted area and overestimates the infarct size as confirmed by follow-up CMR.

In the 1980s, 201Tl scintigraphy helped to introduce noninvasive assessment of myocardial perfusion as an important clinical tool for the detection and management of coronary artery disease (CAD). Monovalent cations such as 201Tl exhibit pharmacokinetics that are very suitable for the assessment of

Pheochromocytomas and paragangliomas are a rare tumor entity originating from adrenomedullary chromaffin cells in the adrenal medulla or in sympathetic, paravertebral ganglia outside the medulla. Small lesions are especially difficult to detect by conventional CT or MRI and even by SPECT with the currently available radiotracers (e.g., metaiodobenzylguanidine [MIBG]). The novel PET radiotracer 18F-flubrobenguane could change the diagnostic paradigm in suspected pheochromocytomas and paragangliomas because of its homology with MIBG and the general advantages of PET imaging. The aim of this retrospective analysis was to evaluate 18F-flubrobenguane in pheochromocytomas and paragangliomas and to investigate the biodistribution in patients. Methods: Twenty-three patients with suspected pheochromocytoma or paraganglioma underwent PET/CT or PET/MRI at 63 ± 24 min after injection of 256 ± 33 MBq of 18F-flubrobenguane. The SUVmean and SUVmax of organs were measured with spheric volumes of interest. Threshold-segmented volumes of interest were used to measure the SUVmean or SUVmax of the tumor lesions. One reader evaluated all cross-sectional imaging datasets (CT or MRI) separately, as well as the PET hybrid datasets, and reported the lesion number and size. The diagnostic certainty for a positive lesion was scored on a 3-point scale. Results:18F-flubrobenguane showed a reproducible, stable biodistribution, with the highest SUVmax and SUVmean being in the thyroid gland (30.3 ± 2.2 and 22.5 ± 1.6, respectively), pancreas (12.2 ± 0.8 and 9.5 ± 0.7, respectively), and tumor lesions (16.8 ± 1.7 and 10.1 ± 1.1, respectively) and the lowest SUVmax and SUVmean being in muscle (1.1 ± 0.06 and 0.7 ± 0.04, respectively) and the lung (2.5 ± 0.17 and 1.85 ± 0.13, respectively). In a subgroup analysis, a significantly higher average SUVmean was seen for both pheochromocytoma and paraganglioma than for healthy adrenal glands (11.9 ± 2.0 vs. 9.9 ± 1.5 vs. 3.7 ± 0.2, respectively). In total, 47 lesions were detected. The reader reported more and smaller lesions with higher certainty in PET hybrid imaging than in conventional imaging; however, statistical significance was not reached. Of the 23 (23/47, 49%) lesions smaller than 1 cm, 61% (14/23) were found on hybrid imaging only. Conclusion: Our preliminary data suggest 18F-flubrobenguane PET to be a new, effective staging tool for patients with suspected pheochromocytoma or paraganglioma. Major advantages are the fast acquisition and high spatial resolution of PET imaging and the intense uptake in tumor lesions, facilitating detection. Further studies are warranted to define the role of 18F-flubrobenguane PET, particularly in comparison to standard diagnostic procedures such as MRI or 123I-MIBG SPECT/CT.

Purpose PASylation® offers the ability to systematically tune and optimize the pharmacokinetics of protein tracers for molecular imaging. Here we report the first clinical translation of a PASylated Fab fragment (89Zr∙Df-HER2-Fab-PAS200) for the molecular imaging of tumor-related HER2 expression. Methods A patient with HER2-positive metastatic breast cancer received 37 MBq of 89Zr∙Df-HER2-Fab-PAS200 at a total mass dose of 70 μg. PET/CT was carried out 6, 24, and 45 h after injection, followed by image analysis of biodistribution, normal organ uptake, and lesion targeting. Results Images show a biodistribution typical for protein tracers, characterized by a prominent blood pool 6 h p.i., which decreased over time. Lesions were detectable as early as 24 h p.i. 89Zr∙Df-HER2-Fab-PAS200 was tolerated well. Conclusion This study demonstrates that a PASylated Fab tracer shows appropriate blood clearance to allow sensitive visualization of small tumor lesions in a clinical setting.

Positron emission tomography (PET) is a non-invasive molecular imaging technology that is constantly expanding, with a high demand for specific antibody-derived imaging probes. The use of tracers based on temperature-sensitive molecules (i. e. Fab, svFab, nanobodies) is increasing and has led us to design a class of chelators based on the structure of 2-aminomethylpiperidine (AMP) with acetic and/or hydroxybenzyl pendant arms (2-AMPTA, NHB-2-AMPDA, and 2-AMPDA-HB), which were investigated as such for {Al18 F}2+ -core chelation efficiency. All the compounds were characterized by HPLC-MS analysis and NMR spectroscopy. The AlF-18 labeling reactions were performed under various conditions (pH/temperature), and the radiolabeled chelates were purified and characterized by radio-TLC and radio-HPLC. The stability of labeled chelates was investigated up to 240 min in human serum (HS), EDTA 5 mM, PBS and 0.9 % NaCl solutions. The in vivo stability of [Al18 F(2-AMPDA-HB)]- was assessed in healthy nude mice (n=6). Radiochemical yields between 55 % and 81 % were obtained at pH 5 and room temperature. High stability in HS was measured for [Al18 F(2-AMPDA-HB)]- , with 90 % of F-18 complexed after 120 min. High stability in vivo, rapid hepatobiliary and renal excretion, with low accumulation of free F-18 in bones were measured. Thus, this new Al18 F-chelator may have a great impact on immuno-PET radiopharmacy, by facilitating the development of new fluorine-18-labeled heat-sensitive biomolecules.