To date, clinical feasibility of imaging Lewy-body pathology and related disease progression in Parkinson's disease (PD) patients remains unclear. Supported by the Michael J. Fox Foundation through Ken Griffin Alpha-Synuclein (ASYN) Imaging Award, we developed [ 11 C]MK-7337, a PET radioligand with high-affinity to ASYN, and performed a first-in-human (FIH) study to determine if imaging relevant pathology in patients with mild to moderate PD was feasible. Radioligand binding experiments with [ 3 H]MK-7337 were conducted in postmortem PD, Alzheimer's disease, and non-diseased brain tissues to profile affinity and selectivity. PET imaging in the A30P (ASYN overexpressing-transgenic) mouse model was utilized to validate the in vivo performance of tracer binding to ASYN pathology. PET imaging in pathology-free non-human primates (NHP) were performed to assess tracer translational suitability for PET imaging of human brains. For the FIH study, a total of eight PD (ASYN SAA+, DAT scan+, H&Y 2-3, on stable PD Rx) and four healthy-elderly (HE) participants were imaged. [ 11 C]MK-7337 PET tracer uptake patterns in the brains of PD and HE participants were compared by standardized uptake value ratio (SUVR) using cortical white matter as a pseudo reference region. In vitro tissue binding studies revealed MK-7337 possessed high affinity (<1 nM) for ASYN pathology with moderate liability of off-target binding. PET imaging in aged A30P mice demonstrated robust displaceable tracer binding in the midbrain/brainstem regions, which had known ASYN pathology. PET imaging in NHP suggested suitable tracer brain kinetics, as well as moderate off-target binding liabilities in vivo. The FIH study confirmed the suitable tracer kinetics of [ 11 C]MK-7337 in human brains, with peak SUV>1 in all scans. Similar patterns of tracer brain distribution and clearance were observed between HE and preclinical NHP PET scans. PD participants revealed elevated SUVRs (when compared to HE) in regions believed to contain early ASYN pathology, specifically the midbrain (including substantia nigra), brainstem/pons, and olfactory epithelium regions. [ 11 C]MK-7337 has demonstrated the feasibility of using a high-affinity ASYN PET radioligand to image alpha-synuclein pathology in PD patients.

PDF file - 719K, Supplemental figure 1. Torin2 on PC-3 wide type cell line, the IB was made after 30 min treatment of drug at indicated concentrations. Supplemental figure 2. Torin1, Torin2, AZD8055 and BEZ235 on HeLa and HCT-116 cell line at different time point with a dose responsive drug treatment. Supplemental figure 3. PET-CT experiment of short term treatment of drugs. Supplemental figure 4. PDG-PET determination of drug treatment response with statistics

S1: Schematic maps of AEG-Prom and PEG-Prom reporter constructs S2: c-MYC protein levels analyzed in prostate cancer cell lines by western blotting using anti-MYC antibody (57-70 kDa) S3: Time course for model maturation with PC3-ML-Luc cells using bioluminescence imaging (BLI) at week 5 after injection of: (A) 5 x 104 cells (intracardiac); (B) 1 x 106 cells (tail vein) S4: Cancer-specific AEG-Prom and PEG-Prom activity shown by bioluminescence imaging (BLI) in an experimental model of human prostate cancer (PC3-ML) S5: Comparison of Luc plasmid delivery to lungs of the PCa group for pAEG-Luc treated and pPEG-Luc treated animals (n = 3, PCa-1-3 in Supplemental Fig. S4), respectively S6: Correlation between AEG-1 promoter-driven Luc expression and metastatic sites by histopathological analysis in a bone metastatic prostate cancer model of prostate cancer metastasis S7: Cancer-Specific AEG-Prom activity shown by bioluminescence imaging (BLI) in experimental models of human prostate cancer (PC3-ML) S8: AEG-Prom-based SPECT/CT imaging detects distant metastasis not identified by NaF- or FDG-PET/CT

PDF file - 806K, Supplemental Figure 1. MRI scans at the indicated time points showing tumor burden in EML4-ALK lung cancer mice treated by crizotinib. Multiple scans from a total of 4 mice are shown. Supplemental Figure 2. Representative MRI images showing that EML4-ALK F1174L mutant lung cancers respond to 17-DMAG and TAE684. Note the development of acquired resistance to 17-DMAG and TAE684 after prolonged treatment. Supplemental Figure 3. Acquired resistance to 17-DMAG and TAE684 in mice bearing tumors driven by the EML4-ALK F1174L mutant can be overcome by the combination of the two drugs.

Supplementary Figures 1-4, Tables 1-4 from Inhibition of ALK, PI3K/MEK, and HSP90 in Murine Lung Adenocarcinoma Induced by <i>EML4-ALK</i> Fusion Oncogene

Legend for Supplemental Figures S1-S8.

Supplementary Methods and Legends from Inhibition of ALK, PI3K/MEK, and HSP90 in Murine Lung Adenocarcinoma Induced by <i>EML4-ALK</i> Fusion Oncogene

Huntington’s disease is caused by a trinucleotide expansion in the HTT gene, which leads to aggregation of mutant huntingtin (mHTT) protein in the brain and neurotoxicity. Direct in vivo measurement of mHTT aggregates in human brain parenchyma is not yet possible. In this first-in-human study, we investigated biodistribution and dosimetry in healthy volunteers of [11C]CHDI-00485180-R ([11C]CHDI-180R) and [11C]CHDI-00485626 ([11C]CHDI-626), two tracers designed for PET imaging of aggregated mHTT in the brain that have been validated in preclinical models. Biodistribution and radiation dosimetry studies were performed in 3 healthy volunteers (age 25.7 ± 0.5 years; 2 F) for [11C]CHDI-180R and in 3 healthy volunteers (age 35.3 ± 6.8 years; 2 F) for [11C]CHDI-626 using sequential whole-body PET-CT. Source organs were delineated in 3D using combined PET and CT data. Individual organ doses and effective doses were determined using OLINDA 2.1. There were no clinically relevant adverse events. The mean effective dose (ED) for [11C]CHDI-180R was 4.58 ± 0.65 μSv/MBq, with highest absorbed doses for liver (16.9 μGy/MBq), heart wall (15.9 μGy/MBq) and small intestine (15.8 μGy/MBq). Mean ED for [11C]CHDI-626 was 5.09 ± 0.06 μSv/MBq with the highest absorbed doses for the gallbladder (26.5 μGy/MBq), small intestine (20.4 μGy/MBq) and liver (19.6 μGy/MBq). Decay-corrected brain uptake curves showed promising kinetics for [11C]CHDI-180R, but for [11C]CHDI-626 an increasing signal over time was found, probably due to accumulation of a brain-penetrant metabolite. [11C]CHDI-180R and [11C]CHDI-626 are safe for in vivo PET imaging in humans. The estimated radiation burden is in line with most 11C-ligands. While [11C]CHDI-180R has promising kinetic properties in the brain, [11C]CHDI-626 is not suitable for human in vivo mHTT PET due to the possibility of a radiometabolite accumulating in brain parenchyma. EudraCT number 2020-002129-27. Clinicaltrials.gov NCT05224115 (retrospectively registered).

Huntington’s disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG trinucleotide expansion in the huntingtin ( HTT ) gene that encodes the pathologic mutant HTT (mHTT) protein with an expanded polyglutamine (polyQ) tract. Whereas several therapeutic programs targeting mHTT expression have advanced to clinical evaluation, methods to visualize mHTT protein species in the living brain are lacking. Here, we demonstrate the development and characterization of a positron emission tomography (PET) imaging radioligand with high affinity and selectivity for mHTT aggregates. This small molecule radiolabeled with 11 C ([ 11 C]CHDI-180R) allowed noninvasive monitoring of mHTT pathology in the brain and could track region- and time-dependent suppression of mHTT in response to therapeutic interventions targeting mHTT expression in a rodent model. We further showed that in these animals, therapeutic agents that lowered mHTT in the striatum had a functional restorative effect that could be measured by preservation of striatal imaging markers, enabling a translational path to assess the functional effect of mHTT lowering.

Alterations in synaptic vesicle glycoprotein 2 A (SV2A) have been associated with several neuropsychiatric and neurodegenerative disorders. Therefore, SV2A positron emission tomography (PET) imaging may provide a unique tool to investigate synaptic density dynamics during disease progression and after therapeutic intervention. This study aims to extensively characterize the novel radioligand [ 18 F]SynVesT-1 for preclinical applications. In C57Bl/6J mice ( n = 39), we assessed the plasma profile of [ 18 F]SynVesT-1, validated the use of a noninvasive image-derived input function (IDIF) compared to an arterial input function (AIF), performed a blocking study with levetiracetam (50 and 200 mg/kg, i.p.) to verify the specificity towards SV2A, examined kinetic models for volume of distribution ( V T ) quantification, and explored test-retest reproducibility of [ 18 F]SynVesT-1 in the central nervous system (CNS). Plasma availability of [ 18 F]SynVesT-1 decreased rapidly (13.4 ± 1.5% at 30 min post-injection). V T based on AIF and IDIF showed excellent agreement (r 2 = 0.95, p < 0.0001) and could be reliably estimated with a 60-min acquisition. The blocking study resulted in a complete blockade with no suitable reference region. Test-retest analysis indicated good reproducibility (mean absolute variability <10%). In conclusion, [ 18 F]SynVesT-1 is selective for SV2A with optimal kinetics representing a candidate tool to quantify CNS synaptic density non-invasively. Keywords Mouse , kinetic modeling , SV2A , synapse density , [ , F]SynVesT-1

Alterations in synaptic vesicle glycoprotein 2 A (SV2A) have been associated with several neuropsychiatric and neurodegenerative disorders. Therefore, SV2A positron emission tomography (PET) imaging may provide a unique tool to investigate synaptic density dynamics during disease progression and after therapeutic intervention. This study aims to extensively characterize the novel radioligand [18F]SynVesT-1 for preclinical applications. In C57Bl/6J mice (n = 39), we assessed the plasma profile of [18F]SynVesT-1, validated the use of a noninvasive image-derived input function (IDIF) compared to an arterial input function (AIF), performed a blocking study with levetiracetam (50 and 200 mg/kg, i.p.) to verify the specificity towards SV2A, examined kinetic models for volume of distribution (VT) quantification, and explored test-retest reproducibility of [18F]SynVesT-1 in the central nervous system (CNS). Plasma availability of [18F]SynVesT-1 decreased rapidly (13.4 ± 1.5% at 30 min post-injection). VT based on AIF and IDIF showed excellent agreement (r2 = 0.95, p < 0.0001) and could be reliably estimated with a 60-min acquisition. The blocking study resulted in a complete blockade with no suitable reference region. Test-retest analysis indicated good reproducibility (mean absolute variability <10%). In conclusion, [18F]SynVesT-1 is selective for SV2A with optimal kinetics representing a candidate tool to quantify CNS synaptic density non-invasively.

Huntington’s disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG trinucleotide expansion in the huntingtin (HTT) gene that encodes the pathologic mutant HTT (mHTT) protein with an expanded polyglutamine (PolyQ) tract. While several therapeutic programs targeting mHTT expression have advanced to clinical evaluation, no method is currently available to visualize mHTT levels in the living brain. Here we demonstrate the development of a positron emission tomography (PET) imaging radioligand with high affinity and selectivity for mHTT aggregates. This small molecule radiolabeled with 11C ([11C]CHDI-180R) enables non-invasive monitoring of mHTT pathology in the brain and can track region-and time-dependent suppression of mHTT in response to therapeutic interventions targeting mHTT expression. We further show that therapeutic agents that lower mHTT in the striatum have a functional restorative effect that can be measured by preservation of striatal imaging markers, enabling a translational path to assess the functional effect of mHTT lowering.

Radiotherapy is a common approach for the treatment of a wide variety of cancer types. Available data indicate that nanoparticles can enhance the effect of radiotherapy. We report the use of human mesenchymal stem cells to selectively deliver gold nanoparticles (GNPs) to MDA-MB-231 breast tumor xenografts in mice for the purpose of enhancing the effect of radiation therapy. Targeted delivery of GNPs to the tumor site, followed by irradiation of the tumor, enabled control of tumor growth. The results indicate that tumor-selective GNP delivery by human mesenchymal stem cells may represent a viable way to enhance the effectiveness of radiotherapy.

SPECT systems using pinhole apertures permit radiolabelled molecular spatial resolution, good energy resolution, and high sensitivity are required. We designed what we consider the “optimal” radionuclide detector system for this task. It should allow studying both detection of unstable atherosclerotic plaques and monitoring the effect of therapies. Using mice is particularly challenging in situations that require several intravenous injections of radiotracers, possibly for weeks or even months, in chronically ill animals. Thus, alternative routes of delivering the radiotracer in tail vein should be investigated. In this study, we have performed preliminary measurements of detection of atherosclerotic plaques in genetically modified mice with high-resolution prototype detector. We have also evaluated the feasibility of assessing left ventricular perfusion by intraperitoneal distributions to be imaged in vivo in small animals. Nevertheless, studying cardiovascular diseases in small animal models is very challenging, and in particular, submillimeter delivering of MIBI-Tc in healthy mice.

Emerging evidence supports a hypothesized role for the α7-nicotinic acetylcholine receptor (α7-nAChR) in the pathophysiology of Alzheimer's disease. 18F-ASEM (3-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-6-18F-fluorodibenzo[b,d]thiophene 5,5-dioxide) is a radioligand for estimating the availability of α7-nAChR in the brain in vivo with PET. Methods: In this cross-sectional study, 14 patients with mild cognitive impairment (MCI), a prodromal stage to dementia, and 17 cognitively intact, elderly controls completed 18F-ASEM PET. For each participant, binding in each region of interest was estimated using Logan graphical analysis with a metabolite-corrected arterial input function. Results: Higher 18F-ASEM binding was observed in MCI patients than in controls across all regions, supporting higher availability of α7-nAChR in MCI. 18F-ASEM binding was not associated with verbal memory in this small MCI sample. Conclusion: These data support use of 18F-ASEM PET to examine further the relationship between α7-nAChR availability and MCI.