Project description:RationaleAlthough infection contributes to morbidity in patients with cystic fibrosis (CF), the host inflammatory response is also an important cause of progressive pulmonary function deterioration. Quantifying the inflammatory burden in these patients is challenging and often requires invasive procedures. Positron emission tomographic imaging with [18F]fluorodeoxyglucose ([18FDG]) could be used as a noninvasive alternative to quantify lung inflammation.ObjectiveTo determine the relationships among lung [18F]FDG uptake, bronchoalveolar lavage (BAL) neutrophil concentrations, and pulmonary function in patients with CF.MethodsTwenty patients and seven healthy volunteers were studied. A subset of seven patients also consented to undergo BAL. The uptake of [18F]FDG by the lungs was measured as the net influx rate constant Ki. Patients were stratified by rate of decline in pulmonary function into stable, intermediate, and rapidly declining groups. Ki was compared among groups and was correlated against neutrophil concentrations in BAL fluid.ResultsKi was significantly elevated (p<0.05) among patients with CF as a whole compared with healthy control subjects (0.0015+/-0.0009 versus 0.0007+/-0.0002 ml blood/ml lung/min) but especially in patients with rapidly declining pulmonary function (0.0022+/-0.0011 ml blood/ml lung/min). Ki correlated positively with the number of neutrophils present in BAL fluid.ConclusionImaging with [18F]fluorodeoxyglucose and positron emission tomography can be used to assess inflammatory burden in patients with CF. Elevations in Ki may be able to identify patients with more aggressive disease and may be useful in monitoring changes in inflammatory burden in response to novel treatments.
Project description:This study aims at identifying genes involved in this metabolic activation potentially related to rupture. A genome-wide transcriptomic analysis was performed on biopsies collected from patients with a Fluorodeoxyglucose (FDG) uptake both in the positive spot (A+Pos) and in a distant negative site of the same aneurysm (A+Neg). These paired biopsies were further compared to samples collected from (abdominal aortic aneurysms) AAA patients with no FDG uptake (A0) in order to discriminate biological alterations associated with FDG uptake, to detect new systemic biomarkers correlated with a higher risk of rupture and to identify new pathways involved in the progression and rupture of AAA).
Project description:Fluorine-18-fluoro-2-deoxy-D-glucose (FDG) is widely used as positron-emission-tomography (PET) radiotracer for the detection and staging of human cancer. Tumor uptake of FDG varies substantially between different cancer types and between patients with the same tumor type. The molecular basis for this heterogeneity is unknown. Using cancer cell lines and primary human tumors of distinct histologic origins, we here show that increased FDG uptake is universally associated with coordinate upregulation of genes within the glycolysis, pentose-phosphate, and other related metabolic pathways. In primary human breast cancers, this FDG signature shows significant overlap with established breast cancer signatures for the “basal-like” disease subtype and “poor prognosis”. FDG high breast cancer showed significantly more gene copy number alterations genome wide than FDG low cancers. About 50 % of primary breast cancers with high FDG uptake and FDG gene expression signature show DNA copy gain encompassing the c-myc gene locus and express gene sets regulated by the transcription factor MYC. Our data shows that FDG-PET marks a distinct subset of “basal-like” human breast cancer which is characterized by MYC and prognostically unfavorable gene expression signatures, suggesting that FDG-PET imaging may be useful to risk-stratify patients with locally advanced breast cancer.
Project description:Colorectal cancer (CRC) is the third most common cancer and the fourth leading cause of cancer deaths worldwide. Integrin ?6 is overexpressed in all stages of CRC which makes it a potential diagnostic biomarker for CRC. Previously, we identified an integrin ?6-targeted peptide CRWYDENAC (dubbed RWY) using phage display technology and employed it for nasopharyngeal carcinoma specific nanotherapeutics. In this study, we developed a radiotracer, 18F-RWY, based on this integrin ?6-targeted RWY peptide for positron emission tomography (PET) imaging of CRC. Integrin ?6 was overexpressed on several CRC cells including HT29 cells where the biotin-labeled RWY peptide colocalized with integrin ?6. 18F-RWY PET imaging was performed on subcutaneous, chemically induced, and genetically engineered CRC mice. 18F-RWY generated high PET signals in subcutaneous HT29 tumors, and the tumor uptake of 18F-RWY was reduced by a blocking study using nonradio-labeled RWY. Moreover, 18F-RWY PET imaging enabled detection of CRC in chemically induced and genetically engineered CRC mice. The overexpression of integrin ?6 in tumor tissues isolated from chemically induced and genetically engineered CRC mice was confirmed. These results demonstrate the potential clinical application of 18F-RWY for PET imaging of CRC.
Project description:Fluorine-18-fluoro-2-deoxy-D-glucose (FDG) is widely used as positron-emission-tomography (PET) radiotracer for the detection and staging of human cancer. Tumor uptake of FDG varies substantially between different cancer types and between patients with the same tumor type. The molecular basis for this heterogeneity is unknown. Using cancer cell lines and primary human tumors of distinct histologic origins, we here show that increased FDG uptake is universally associated with coordinate upregulation of genes within the glycolysis, pentose-phosphate, and other related metabolic pathways. In primary human breast cancers, this FDG signature shows significant overlap with established breast cancer signatures for the “basal-like” disease subtype and “poor prognosis”. FDG high breast cancer showed significantly more gene copy number alterations genome wide than FDG low cancers. About 50 % of primary breast cancers with high FDG uptake and FDG gene expression signature show DNA copy gain encompassing the c-myc gene locus and express gene sets regulated by the transcription factor MYC. Our data shows that FDG-PET marks a distinct subset of “basal-like” human breast cancer which is characterized by MYC and prognostically unfavorable gene expression signatures, suggesting that FDG-PET imaging may be useful to risk-stratify patients with locally advanced breast cancer. Our general strategy to identify molecular determinants of FDG-retention through a genome-wide approach consisted of FDG uptake measurements in cancer cell lines and primary human tumors, the selection of samples with particularly high versus low FDG-retention, and subsequent pathway-based analysis of RNA expression data collected from these samples. Cell line RNA was extracted from a 10 cm plate seeded simultaneously and at the same density as the wells for FDG-uptake assays. For primary human tumor samples, RNA was extracted from macrodissected frozen tumor tissue. All cell line RNA samples and the astrocytoma RNA aliquots were hybridized to Affymetrix U133 Plus 2.0 arrays. All primary breast cancer RNA samples were hybridized to Affymetrix U133A arrays.
Project description:The standardized uptake value (SUV), an indicator of the glucose uptake degree in 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), has been used as a prognostic factor in malignant tumors. We aimed to identify a signature reflecting prognostic SUV characteristics in breast cancer (BRC). Transcriptome profiling was performed to identify a signature associated with the SUV in BRC patients who underwent preoperative FDG-PET. We defined a signature consisting of 723 genes significantly correlated with the SUV (|r| > .35; P < .001). The patient subgroups classified by the signature were significantly similar to those classified by the SUV (odds ratio, 8.02; 95% CI, 2.45 to 29.3; P < 0.001). The SUV signature showed independent clinical utility for predicting BRC prognosis (hazard ratio, 1.25; 95% CI, 1.11 to 1.42; P < 0.001). Integrative analysis demonstrated a significance of the signature in predicting the response to immunotherapy and revealed that a signaling axis defined by TP53-FOXM1 and its downstream effectors in glycolysis-gluconeogenesis, including LDHA, might be important mediators in the FDG-PET process. Our results reveal characteristics of glucose uptake captured by FDG-PET, supporting an understanding of glucose metabolism as well as poor prognosis in BRC patients with a high SUV.
Project description:Chimeric antigen receptor (CAR) T cell therapy for hematologic malignancies is fraught with several unknowns, including number of functional T cells that engage target tumor, durability and subsequent expansion and contraction of that engagement, and whether toxicity can be managed. Non-invasive, serial imaging of CAR T cell therapy using a reporter transgene can address those issues quantitatively. We have transduced anti-CD19 CAR T cells with the prostate-specific membrane antigen (PSMA) because it is a human protein with restricted normal tissue expression and has an expanding array of positron emission tomography (PET) and therapeutic radioligands. We demonstrate that CD19-tPSMA(N9del) CAR T cells can be tracked with [18F]DCFPyL PET in a Nalm6 model of acute lymphoblastic leukemia. Divergence between the number of CD19-tPSMA(N9del) CAR T cells in peripheral blood and bone marrow and those in tumor was evident. These findings underscore the need for non-invasive repeatable monitoring of CAR T cell disposition clinically.
Project description:Positron emission tomography (PET) visualizes increased cellular [F]fluorodeoxyglucose ([F]FDG) uptake. Pulmonary hypertension (PH) is conceived of a proliferative disease of the lung vessels. Increased glucose uptake can be quantified as pulmonary [F]FDG uptake via PET imaging. Because the angioproliferative mechanisms in PH are still in need of further description, the aim of the present study was to investigate whether [F]FDG PET/CT imaging can elucidate these pathophysiologic mechanisms in different etiologies of PH.Patients (n?=?109) with end-stage pulmonary disease being evaluated for lung transplant were included in this observational study. Mean standardized uptake value (SUVmean) of predefined regions of interest in lung parenchyma (LP), left (LV), and right ventricle (RV) of the heart, and SUVmax in pulmonary artery (PA) were determined and normalized to liver uptake. These SUV ratios (SUVRs) were compared with results from right heart catheterization (mean pulmonary artery pressure [mPAP], pulmonary vascular resistance [PVR]), and serum N-terminal pro-brain natriuretic peptide. Group comparisons were performed and Pearson correlation coefficients (r) were calculated.The [F]FDG uptake ratios in LP, RV, RV/LV, and PA, but not in LV, were found to be significantly higher in both patients with mPAP ?25?mm Hg (P?=?0.013, P?=?0.006, P?=?0.049, P?=?0.002, P?=?0.68, respectively) and with PVR ?480?dyn·s/cm (P?<?0.001, P?=?0.045, P?<?0.001, P?<?0.001, P?=?0.26, respectively). The [F]FDG uptake in these regions positively correlated also with mPAP, PVR, and N-terminal pro-brain natriuretic peptide. The SUVR of PA positively correlated with the SUVR of LP and RV (r?=?0.55, r?=?0.42, respectively).Pulmonary and cardiac [F]FDG uptake in PET imaging positively correlated with the presence and severity of PH in patients with end-stage pulmonary disease. Increased glucose metabolism in the central PAs seems to play a certain role in terms of severity of PH. These results suggest that [F]FDG-PET imaging can help understand the pathophysiology of PH as a proliferative pulmonary disease.
Project description:COPD and smoking are characterised by pulmonary inflammation. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging may improve knowledge of pulmonary inflammation in COPD patients and aid early development of novel therapies as an imaging biomarker. To evaluate pulmonary inflammation, assessed by FDG uptake, in whole and regional lung in "usual" (smoking-related) COPD patients, alpha-1 antitrypsin deficiency (α1ATD) COPD patients, smokers without COPD and never-smokers using FDG PET/CT. Secondly, to explore cross-sectional associations between FDG PET/CT and systemic inflammatory markers in COPD patients and repeatability of the technique in COPD patients. Data from two imaging studies were evaluated. Pulmonary FDG uptake (normalised Ki; nKi) was measured by Patlak graphical analysis in four subject groups: 84 COPD patients, 11 α1ATD-COPD patients, 12 smokers and 10 never-smokers. Within the COPD group, associations between nKi and systemic markers of inflammation were assessed. Repeatability was evaluated in 32 COPD patients comparing nKi values at baseline and at 4-month follow-up. COPD patients, α1ATD-COPD patients and smokers had increased whole lung FDG uptake (nKi) compared with never-smokers (0.0037±0.001, 0.0040±0.001, 0.0040±0.001 versus 0.0028±0.001 mL·cm-3·min-1, respectively, p<0.05 for all). Similar results were observed in upper and middle lung regions. In COPD participants, plasma fibrinogen was associated with whole lung nKi (β=0.30, p=0.02) in multivariate analysis adjusted for current smoking, forced expiratory volume in 1 s % predicted, systemic neutrophils and C-reactive protein levels. Mean percentage difference in nKi between the baseline and follow-up was 3.2%, and the within subject coefficient of variability was 7.7%. FDG PET/CT has potential as a noninvasive tool to enable whole lung and regional quantification of FDG uptake to assess smoking- and COPD-related pulmonary inflammation.
Project description:The glucagon receptor (GCGR) is emerging as an important target in anti-diabetic therapy, especially as part of the pharmacology of dual glucagon-like peptide-1/glucagon (GLP-1/GCG) receptor agonists. However, currently, there are no suitable biomarkers that reliably demonstrate GCG receptor target engagement.MethodsTwo potent GCG receptor peptide agonists, S01-GCG and S02-GCG, were labeled with positron emission tomography (PET) radionuclide gallium-68. The GCG receptor binding affinity and specificity of the resulting radiopharmaceuticals [68Ga]Ga-DO3A-S01-GCG and [68Ga]Ga-DO3A-S02-GCG were evaluated in HEK-293 cells overexpressing the human GCG receptor and on frozen hepatic sections from human, non-human primate, and rat. In in vivo biodistribution, binding specificity and dosimetry were assessed in rat.Results[68Ga]Ga-DO3A-S01-GCG in particular demonstrated GCG receptor-mediated binding in cells and liver tissue with affinity in the nanomolar range required for imaging. [68Ga]Ga-DO3A-S01-GCG binding was not blocked by co-incubation of a GLP-1 agonist. In vivo binding in rat liver was GCG receptor specific with low non-specific binding throughout the body. Moreover, the extrapolated human effective doses, predicted from rat biodistribution data, allow for repeated PET imaging potentially also in combination with GLP-1R radiopharmaceuticals.Conclusion[68Ga]Ga-DO3A-S01-GCG thus constitutes a first-in-class PET tracer targeting the GCG receptor, with suitable properties for clinical development. This tool has potential to provide direct quantitative evidence of GCG receptor occupancy in humans.