Project description:Purpose: Building a universal genomic signature predicting the intensity of FDG uptake in diverse metastatic tumors may allow us to understand better the biological processes underlying this phenomenon and their requirements of glucose uptake. Methods: A balanced training set (n=71) of metastatic tumors including some of the most frequent histologies, with matched PET/CT quantification measurements and whole human genome gene expression microarrays, was used to build the signature. Selection of microarray features was carried out exclusively on the basis of their strong association with FDG uptake (as measured by SUVmean35) by means of univariate linear regression. A thorough bioinformatics study of these genes was performed and multivariable models were built by fitting several state of the art regression techniques to the training set for comparison. Results: The 909 probes with the strongest association with the SUVmean35 (comprising 742 identifiable genes and 62 probes not matched to a symbol) were used to build the signature. Partial Least Squares using 3 components (PLS-3) was the best performing model in the training dataset cross-validation (Root Mean Square Error, RMSE=0.443) and was validated further in an independent validation dataset (n=13) obtaining a performance within the 95% CI of that obtained in the training dataset (RMSE=0.645). Significantly overrepresented biological processes correlating with the SUVmean35 were identified beyond glycolysis, such as ribosome biogenesis and DNA replication (correlating with a higher SUVmean35), and cytoskeleton reorganization and autophagy (correlating with a lower SUVmean35), among others. Conclusions: PLS-3 is a signature predicting accurately the intensity of FDG uptake in diverse metastatic tumors. FDG-PET might help in the design of specific targeted therapies directed to counteract the identified malignant biological processes more likely activated in a tumor as inferred from the SUVmean35 and also from its variations in response to antineoplastic treatments.
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: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 triple negative breast cancer (TNBC). Transcriptome profiling was performed to identify a signature associated with the SUV in TNBC patients who underwent preoperative FDG-PET. We defined a signature significantly associated with the SUV (|r| > .35; P < .01). The SUV signature showed independent clinical utility for predicting BRC prognosis. 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 TNBC patients with a high SUV.
Project description:BACKGROUND:Building a universal genomic signature predicting the intensity of FDG uptake in diverse metastatic tumors may allow us to understand better the biological processes underlying this phenomenon and their requirements of glucose uptake. METHODS:A balanced training set (n?=?71) of metastatic tumors including some of the most frequent histologies, with matched PET/CT quantification measurements and whole human genome gene expression microarrays, was used to build the signature. Selection of microarray features was carried out exclusively on the basis of their strong association with FDG uptake (as measured by SUVmean35) by means of univariate linear regression. A thorough bioinformatics study of these genes was performed, and multivariable models were built by fitting several state of the art regression techniques to the training set for comparison. RESULTS:The 909 probes with the strongest association with the SUVmean35 (comprising 742 identifiable genes and 62 probes not matched to a symbol) were used to build the signature. Partial least squares using three components (PLS-3) was the best performing model in the training dataset cross-validation (root mean square error, RMSE?=?0.443) and was validated further in an independent validation dataset (n?=?13) obtaining a performance within the 95% CI of that obtained in the training dataset (RMSE?=?0.645). Significantly overrepresented biological processes correlating with the SUVmean35 were identified beyond glycolysis, such as ribosome biogenesis and DNA replication (correlating with a higher SUVmean35) and cytoskeleton reorganization and autophagy (correlating with a lower SUVmean35). CONCLUSIONS:PLS-3 is a signature predicting accurately the intensity of FDG uptake in diverse metastatic tumors. FDG-PET might help in the design of specific targeted therapies directed to counteract the identified malignant biological processes more likely activated in a tumor as inferred from the SUVmean35 and also from its variations in response to antineoplastic treatments.
Project description:BACKGROUND. Improving and predicting tumor response to immunotherapy remains challenging. Combination therapy with a transforming growth factor β (TGF-β) inhibitor that targets cancer associated fibroblasts (CAFs) is promising to enhance efficacy of cancer immunotherapies. However, the effect of this approach in clinical trials is limited, requiring in vivo methods to better assess tumor responses to combination therapy. METHODS. We measure CAFs in vivo using gallium 68-labeled fibroblast activation protein inhibitor (68Ga-FAPI) for PET/CT imaging to guide TGF-β inhibition and sensitize metastatic colorectal cancer (CRC) to immunotherapy. A total of 131 patients with metastatic CRC underwent 68Ga-FAPI and 18F-fludeoxyglucose (18F-FDG) PET/CT imaging. Fourteen patients underwent surgery after the imaging. Relationship between uptake of 68Ga-FAPI and tumor immunity was analyzed. Mouse cohorts of metastatic CRC were treated with TGF-β receptor (TGF-βR) inhibitor combined with KN046 which blocks PD-L1 and CTLA4, followed with 68Ga-FAPI and 18F-FDG micro-PET/CT imaging to assess tumor responses. RESULTS. Patients with metastatic CRC demonstrated high uptakes of 68Ga-FAPI, along with suppressive tumor immunity and poor prognosis. TGF-βR inhibitor enhanced tumor infiltrating T cells and significantly sensitized metastatic CRC to KN046. 68Ga-FAPI PET/CT imaging accurately monitored the dynamical changes of CAFs and tumor response to combined TGF-βR inhibitor with immunotherapy. CONCLUSION. 68Ga-FAPI PET/CT imaging is powerful in assessing tumor immunity and response to immunotherapy in metastatic CRC. This study supports future clinical application of 68Ga-FAPI PET/CT to stratify and guide patients with CRC for precise TGF-β inhibition plus immunotherapy, recommending 68Ga-FAPI and 18F-FDG dual PET/CT for CRC management.
Project description:Rationale: Estrogens attenuate cardiac hypertrophy and increase cardiac contractility via their cognate receptors ERα and ERβ. Since female sex hormones enhance global glucose utilization and because myocardial function and mass are tightly linked to cardiac glucose metabolism we tested the hypothesis that expression and activation of the estrogen receptor α (ERα) might be required and sufficient to maintain physiological cardiac glucose uptake in the murine heart. Methods and Results: Cardiac glucose uptake quantified in vivo by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was strongly impaired in ovarectomized compared to gonadal intact female C57BL/6JO mice. The selective ERα agonist 16α-LE2 and the non-selective ERα and ERβ agonist 17β-estradiol completely restored cardiac glucose uptake in ovarectomized mice. Cardiac FDG uptake was strongly decreased in female ERα knockout mice (ERKO) compared to wild type littermates. Biochemical assays, affymetrix cDNA array analysis, western blotting and immuno-staining of cardiac glucose transporters revealed a positive correlation of ERα dependent cardiac FDG uptake with preserved cardiac glucose transporter-1 expression and micro-vascular localization. Conclusions: Systemic activation of the ERα estrogen receptor is sufficient and its expression is required to maintain physiological glucose uptake in the murine heart, which is likely to contribute to known cardio-protective estrogen effects. total samples analysed are 20
Project description:Microglia is dynamically reprogrammed according to the progression of Alzheimer’s disease (AD). However, clinical translation into biomarker development for functional change in microglia has not been achieved. Here, we find the close association of the metabolic reconfiguration of microglia with increased hippocampal glucose uptake, which can be noninvasively estimated by [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET). We found that increased FDG activity in the hippocampus of an AD mouse model depended on microglial uptake. Single-cell RNA-sequencing of the hippocampus showed the changes of glucose metabolism profiles including glucose transporters, glycolysis and oxidative phosphorylation mainly occurred in microglia. A subset of microglia with high glucose transporters with defective glycolysis and oxidative phosphorylation was increased according to disease progression. Furthermore, we also found a positive association between a soluble TREM2 of cerebrospinal fluid, a marker of microglial activation, and hippocampal FDG uptake as a human study. We identified a reconfiguration of microglial glucose metabolism in the hippocampus of AD and suggested a feasible imaging biomarker based on widely used FDG PET to reflect microglial metabolic profiles.
Project description:Rationale: Estrogens attenuate cardiac hypertrophy and increase cardiac contractility via their cognate receptors ERα and ERβ. Since female sex hormones enhance global glucose utilization and because myocardial function and mass are tightly linked to cardiac glucose metabolism we tested the hypothesis that expression and activation of the estrogen receptor α (ERα) might be required and sufficient to maintain physiological cardiac glucose uptake in the murine heart. Methods and Results: Cardiac glucose uptake quantified in vivo by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was strongly impaired in ovarectomized compared to gonadal intact female C57BL/6JO mice. The selective ERα agonist 16α-LE2 and the non-selective ERα and ERβ agonist 17β-estradiol completely restored cardiac glucose uptake in ovarectomized mice. Cardiac FDG uptake was strongly decreased in female ERα knockout mice (ERKO) compared to wild type littermates. Biochemical assays, affymetrix cDNA array analysis, western blotting and immuno-staining of cardiac glucose transporters revealed a positive correlation of ERα dependent cardiac FDG uptake with preserved cardiac glucose transporter-1 expression and micro-vascular localization. Conclusions: Systemic activation of the ERα estrogen receptor is sufficient and its expression is required to maintain physiological glucose uptake in the murine heart, which is likely to contribute to known cardio-protective estrogen effects.
Project description:Although FDG-PET is widely used in cancer, its role in gastric cancer (GC) is still controversial due to variable [18F]fluorodeoxyglucose ([18F]FDG) uptake. Here, we investigate the molecular landscape of GC and its association with glucose metabolic profiles noninvasively evaluated by [18F]FDG PET. Based on a genetic signature, PETscore, representing [18F]FDG avidity, was developed by imaging data acquired from thirty patient-derived xenografts (PDX). Five genes, PLS1, PYY, HBQ1, SLC6A5, NAT16, were identified for the PETscore, which was validated in independent cohorts by qRT-PCR and RNA-sequencing. By applying the PETscore on the Cancer Genome Atlas (TCGA), a significant association between glucose uptake and tumor mutational burden as well as genomic alterations was identified in GC. Our findings suggest that molecular characteristics are underlying the diverse metabolic profiles of GC. Diverse glucose metabolic profiles may apply to precise diagnostic and therapeutic approaches for GC.
Project description:The feasibility of longitudinal metastatic biopsies for gene expression profiling in breast cancer is unexplored. Dynamic changes in gene expression can potentially predict efficacy of targeted cancer drugs. Patients enrolled in a phase III trial of metastatic breast cancer with sunitinib combined with docetaxel (SU+DOC) versus docetaxel alone (DOC) were offered to participate in a translational substudy comprising longitudinal fine needle aspiration biopsies (FNAB) and positron emission imaging before (T1) and two weeks after start of treatment (T2). Aspirated tumor material was used for microarray analysis, and treatment-induced changes (T2 versus T1) in gene expression and standardized uptake values were investigated. Twenty-one patients were included in the docetaxel ± sunitinib trial at Karolinska and 18 of them agreed to participate in the substudy. Of the 18 women enrolled, 8 were randomly assigned to SU+DOC and 10 to DOC. Metastatic FNAB were carried out in 17 of the 18 patients at both time points with no complications reported. Representative tumor material, sufficient for RNA extraction was obtained in 15 patients at T1 and 14 patients at T2. Matched samples both at T1 and T2 were obtained for 14 subjects, 7 in each arm. The main objective was to determine whether gene expression profiling is feasible using sequential, intra-patient FNAB. Secondary objectives were to identify potential biomarkers of early response by gene expression and/or functional imaging and to explore drug action in vivo by changes in gene expression. A Karolinska substudy of the docetaxel ± sunitinib phase III clinical trial utilising sequential metastatic fine needle aspiration biopsies (FNAB) and 18-F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT). In brief, the randomized docetaxel ± sunitinib trial compared sunitinib combined with docetaxel (SU+DOC) versus docetaxel alone (DOC), as first line therapy in patients with HER2 negative metastatic breast cancer. Patients in the exploratory substudy were subjected to baseline FDG PET/CT assessment, followed by FNAB of one tumor lesion prior to start of treatment (Time point T1). FDG PET/CT and FNAB were repeated at Day 14 ± 1 (Time point T2) when sunitinib has achieved steady state.