Delineating, Imaging, and Assessing Pulmonary Fibrosis Remodeling via Collagen Hybridization.

Idiopathic pulmonary fibrosis (IPF) is a progressive, life-threatening disease with no early detection, few treatments, and dismal outcomes. Although collagen overdeposition is a hallmark of lung fibrosis, current research mostly focuses on the cellular aspect, leaving collagen, particularly its dynamic remodeling (i.e., degradation and turnover), largely unexplored. Here, using a collagen hybridizing peptide (CHP) that specifically binds unfolded collagen chains, we reveal vast collagen denaturation in human IPF lungs and delineate the spatiotemporal progression of collagen denaturation three-dimensionally within fibrotic lungs in mice. Transcriptomic analyses support that lung collagen denaturation is strongly associated with up-regulated collagen catabolism in mice and patients. We thus show that CHP probing differentiates remodeling responses to antifibrotics and highlights the resolution of established fibrosis by agents up-regulating collagen catabolism. We further develop a radioactive CHP that detects fibrosis in vivo in mice as early as 7 days postlung-injury (Ashcroft score: 2-3) by positron emission tomography (PET) imaging and ex vivo in clinical lung specimens. These findings establish collagen denaturation as a promising marker of fibrotic remodeling for the investigation, diagnosis, and therapeutic development of pulmonary fibrosis.

Effectiveness of electro-acupuncture for cognitive improvement on Alzheimer's disease quantified via PET imaging of sphingosine-1-phosphate receptor 1.

INTRODUCTION: Electro-acupuncture (EA) has demonstrated potential in improving mild-to-moderate dementia in clinics, but the underlying scientific target remains unclear. METHODS: EA was administered to APP/PS1 Alzheimer's disease (AD) mice, with untreated AD, and wild type (WT) mice serving as controls. The efficacy of EA was assessed by the Morris water maze cognitive functional tests. Brain magnetic resonance imaging-positron emission tomography (PET) scans using [18F]TZ4877 targeting sphingosine-1-phosphate receptor 1 (S1PR1) and [18F]AV45 targeting amyloid beta fibrils were conducted. The correlation between regional brain PET quantifications and cognitive functions was analyzed. RESULTS: EA significantly improved cognitive and memory functions of AD (p  = 0.04) and reduced the uptake of [18F]TZ4877 in the cortex (p  = 0.02) and hippocampus (p  = 0.03). Immunofluorescence confirmed colocalizations of S1PR1 with glial fibrillary acidic protein and ionized calcium-binding adaptor molecule-1. Furthermore, immunohistochemistry showed a significant reduction of interleukin 1ß and tumor necrosis factor α after EA treatment. DISCUSSION: EA may reverse AD by suppressing neuroinflammation, and the PET imaging of S1PR1 seemed potent in evaluating the treatment for AD patients HIGHLIGHTS: Electro-acupuncture (EA) was administered to APP/PS1 Alzheimer's disease (AD) mice, with untreated AD, and wild type (WT) mice serving as controls. The efficacy of EA was assessed by the Morris water maze cognitive functional tests and positron emission tomography (PET) imaging quantifications. PET tracer [18F]AV45 was used to detect amyloid beta deposition. An increased uptake of [18F]AV45 was found in AD compared to WT mice, with significance observed only in the cortex and not in the hippocampus. EA treatment exhibited a trend toward reduced [18F]AV45 uptake in AD mouse brains post-treatment. However, statistical difference was not attained in most brain regions. EA "Baihui (DU20) and Sishencong (EX-HN1)" significantly improved cognitive and memory functions of AD (p = 0.04). Brain magnetic resonance imaging p(MRI)-positron emission tomography (PET) quantifications revealed that significantly reduced the uptake of [18F]TZ4877 in the cortex (p = 0.02) and hippocampus (p = 0.03) after EA treatment. The correlation between PET quantifications and cognitive functions was analyzed and the most notable correlations were found between escape latency (reaction cognitive and memory behavior) and volume distribution (VT) quantifications of [18F]TZ4877. VT quantifications of [18F]TZ4877 in key brain regions for cognitive and memory ability, such as the cortex and hippocampus, positively correlated with platform latency (cortex p < 0.01, r = 0.7102; hippocampus p < 0.01, r = 0.6891). Immunofluorescence confirmed colocalizations of S1PR1 with glial fibrillary acidic protein and ionized calcium-binding adaptor molecule-1 in the AD brain. And the EA treatment significantly reduced the signals in the cortex and hippocampus. Immunohistochemistry showed a significant reduction of interleukin 1ß and tumor necrosis factor α after EA treatment. EA reversed AD by suppressing neuroinflammation in the cortex and hippocampus. The S1PR1 targeting PET tracer [18F]TZ4877 showed promise in evaluating the pathological progression of AD in clinical settings.

Synthesis and Evaluation of [64Cu]Cu-NOTA-HFn for PET Imaging of Transferrin Receptor 1 Expression in Nasopharyngeal Carcinoma.

As recurrent and metastatic nasopharyngeal carcinoma (NPC) is the most common cause of death among patients with NPC, there is an urgent clinical need for the development of precision diagnosis to guide personalized treatment. Recent emerging evidence substantiates the increased expression of transferrin receptor 1 (also known as cluster of differentiation 71, CD71) within tumor tissues and the inherent targeting capability of natural heavy-chain ferritin (HFn) toward CD71. This study aimed to synthesize and assess a radiotracer ([64Cu]Cu-NOTA-HFn) designed to target CD71 for positron emission tomography (PET) imaging in an NPC tumor-bearing mouse model. The entire radiolabeling process of [64Cu]Cu-NOTA-HFn was completed within 15 min with high yield (>98.5%) and high molar activity (72.96 ± 21.33 GBq/µmol). The in vitro solubility and stability experiments indicated that [64Cu]Cu-NOTA-HFn had a high water solubility (log P = -2.42 ± 0.52, n = 6) and good stability in phosphate-buffered saline (PBS) for up to 48 h. The cell saturation binding assay indicated that [64Cu]Cu-NOTA-HFn had a nanomolar affinity (Kd = 10.9 ± 6.1 nM) for CD71-overexpressing C666-1 cells. To test the target engagement in vivo, prolonged-time PET imaging was performed at 1, 6, 12, 24, and 36 h postinjection (p.i.) of [64Cu]Cu-NOTA-HFn to C666-1 NPC tumor-bearing mice. The C666-1 tumors could be visualized by [64Cu]Cu-NOTA-HFn and blocked by nonradiolabeled HFn. PET imaging quantitative analysis demonstrated that the uptake of [64Cu]Cu-NOTA-HFn in C666-1 tumors peaked at 6 h p.i. and the best radioactive tumor-to-muscle ratio was 10.53 ± 3.11 (n = 3). Ex vivo biodistribution assay at 6 h p.i. showed that the tumor uptakes were 1.43 ± 0.23%ID/g in the nonblock group and 0.92 ± 0.2%ID/g in the block group (n = 3, p < 0.05). Immunohistochemistry and immunofluorescence staining confirmed positive expression of CD71 and the uptake of HFn in C666-1 tumor tissues. In conclusion, our experiments demonstrated that [64Cu]Cu-NOTA-HFn possesses a very high target engagement for CD71-positive NPC tumors and provided a fundamental basis for further clinical translation.

Chitosan -NH2 derived efficient Co3O4 catalyst for styrene catalytic oxidation: Simultaneously regulating particle size and Co valence.

In this study, a Co3O4 catalyst is synthesised using the chitosan-assisted sol-gel method, which simultaneously regulates the grain size, Co valence and surface acidity of the catalyst through a chitosan functional group. The complexation of the free -NH2 complex inhibits particle agglomeration; thus, the average particle size of the catalyst decreases from 82 to 31 nm. Concurrently, Raman spectroscopy, hydrogen temperature-programmed reduction, electron paramagnetic resonance spectroscopy and X-ray photoelectron spectroscopy experiments demonstrate that doping with chitosan N sources effectively modulates Co2+ to promote the formation of oxygen vacancies. In addition, water washing after catalyst preparation can considerably improve the low-temperature (below 250 °C) activity of the catalyst and eliminate the side effects of alkali metal on catalyst activity. Moreover, the presence of Brønsted and Lewis acid sites promotes the adsorption of C8H8. Consequently, CS/Co3O4-W presents the highest catalytic oxidation activity for C8H8 at low temperatures (R250 °C = 8.33 µmol g-1 s-1, WHSV = 120,000 mL hr-1∙g-1). In situ DRIFTS and 18O2 isotope experiments demonstrate that the oxidation of the C8H8 reaction is primarily dominated by the Mars-van Krevelen mechanism. Furthermore, CS/Co3O4-W exhibits superior water resistance (1- and 2- vol% H2O), which has the potential to be implemented in industrial applications.

The role of (18F)-fluoro-D-glucose positron emission tomography/computed tomography in the surveillance of abnormal myocardial energy metabolism and cardiac dysfunction in a rat model of cardiopulmonary resuscitation.

PURPOSE: To investigate the feasibility and usefulness of 2-deoxy-2-(18F)-fluoro-D-glucose positron emission tomography/computed tomography [(18F)-FDG PET/CT] as a novel examination in the surveillance of abnormal myocardial energy metabolism and cardiac dysfunction after cardiopulmonary resuscitation (CPR). METHODS: Thirteen male Sprague-Dawley rats were randomly divided into a sham group (n = 4), CPR group (n = 4), and trimetazidine (TMZ) + CPR group (n = 5). The expression levels of the myocardial injury marker cardiac troponin I (CTNI) in serum were tested at 6 hours after CPR or TMZ + CPR. The ejection fraction and fraction shortening were evaluated by echocardiography. (18F)-FDG PET/CT was used to measure the FDG uptake and the standardized uptake value (SUV) after CPR or TMZ + CPR for 6 hours. The intermediary carbohydrate metabolites of glycolysis including phosphoenolpyruvate, 3-phospho-D-glycerate, and the lactate/pyruvate ratio were detected through the multiple reaction monitoring approach. Simultaneously, the authors also tested the expression levels of the total adenosine triphosphate (ATP) and the key intermediate products of glucose ovidation as alpha ketoglutarate, citrate, and succinate in the myocardium. RESULTS: The authors found that the aerobic oxidation of glucose was reduced, and the anaerobic glycolysis was significantly enhanced in the myocardium in the early stage of CPR. Meanwhile, the myocardial injury marker CTNI was upregulated considerably (P = 0.014, P = 0.021), and the left ventricular function of the animal heart also markedly deteriorated with the downregulation of ATP after CPR. In contrast, myocardial injury and cardiac function were greatly improved with the increase of ATP in the CPR + TMZ group. In addition, aerobic glucose oxidation metabolites were significantly increased (P < 0.05) and anaerobic glycolysis metabolites were significantly decreased (P < 0.05) after CPR in the myocardium. Surprisingly, (18F)-FDG PET/CT could track the above changes by detecting the FDG uptake value and the SUV. CONCLUSION: Glucose metabolism is an essential factor for myocardial self-repair after CPR. (18F) FDG PET/CT, as a non-invasive technology, can monitor myocardial energy metabolism and cardiac function by tracking changes in glucose metabolism after CPR.

The imaging quantification of multiple organs by dynamic 18F-FDG PET/CT in discharged COVID-19 patients: A prospective pilot study.

Purpose: To early identify abnormal lesions by applying the 18F-FDG PET dynamic modeling approach for discharged patients recovering from COVID-19. Methods: Seven discharged COVID-19 patients (COVID-19 group), twelve healthy volunteers (control group 1), and eight cancer patients with normal pulmonary function (control group 2) were prospectively enrolled. Control group 1 completed static 18F-FDG PET/CT only; COVID-19 group and control group 2 completed 60-min dynamic 18F-FDG PET/CT. Among COVID-19 group and control group 2, the uptake of FDG on the last frame (at 55-60 min) of dynamic scans was used for static analysis. Prior to performing scans, COVID-19 patients provided negative real-time Reverse Transcription-Polymerase Chain Reaction (rRT-PCR) of SARS-CoV-2, normal lung functions test, and normal laboratory test. Organ-to-liver standard uptake ratio (OLR, i.e. SUVmax evaluated organ/ SUVmax liver) from conventional static data and Patlak analysis based on the dynamic modeling to calculate the 18F-FDG net uptake rate constant (Ki) were performed. Results: Compared to the control groups, COVID-19 patients at two to three months after discharge still maintained significantly higher Ki values in multiple organs (including lung, bone marrow, lymph nodes, myocardium and liver), although results for regular OLR measurements were normal for all discharged COVID-19 patients. Taking the image of lung as an example, the differences of SUVmax images between COVID-19 group and control group were hard to distinguish. In contrast, a high 18F-FDG signal of the lung among the COVID-19 group was observed for Ki images. Conclusion: The Ki from 18F-FDG PET/CT dynamic imaging quantification might contribute to identifying residual lesions for COVID-19 survivors. Trial registration: The trial is registered with ClinicalTrials.gov, number NCT04519255 (IRB-approved number, K52-1).

A Positron Emission Tomography Tracer Targeting the S2 Subunit of SARS-CoV-2 in Extrapulmonary Infections.

Tracking the pathogen of coronavirus disease 2019 (COVID-19) in live subjects may help estimate the spatiotemporal distribution of SARS-CoV-2 infection in vivo. This study developed a positron emission tomography (PET) tracer of the S2 subunit of spike (S) protein for imaging SARS-CoV-2. A pan-coronavirus inhibitor, EK1 peptide, was synthesized and radiolabeled with copper-64 after being conjugated with 1,4,7-triazacyclononane-1,4,7-triyl-triacetic acid (NOTA). The in vitro stability tests indicated that [64Cu]Cu-NOTA-EK1 was stable up to 24 h both in saline and in human serum. The binding assay showed that [64Cu]Cu-NOTA-EK1 has a nanomolar affinity (Ki = 3.94 ± 0.51 nM) with the S-protein of SARS-CoV-2. The cell uptake evaluation used HEK293T/S+ and HEK293T/S- cell lines that showed that the tracer has a high affinity with the S-protein on the cellular level. For the in vivo study, we tested [64Cu]Cu-NOTA-EK1 in HEK293T/S+ cell xenograft-bearing mice (n = 3) and pseudovirus of SARS-CoV-2-infected HEK293T/ACE2 cell bearing mice (n = 3). The best radioactive xenograft-to-muscle ratio (X/Nxenograft 8.04 ± 0.99, X/Npseudovirus 6.47 ± 0.71) was most evident 4 h postinjection. Finally, PET imaging in the surrogate mouse model of beta-coronavirus, mouse hepatic virus-A59 infection in C57BL/6 J mice showed significantly enhanced accumulation in the liver than in the uninfected mice (1.626 ± 0.136 vs 0.871 ± 0.086 %ID/g, n = 3, P < 0.05) at 4 h postinjection. In conclusion, our experimental results demonstrate that [64Cu]Cu-NOTA-EK1 is a potential molecular imaging probe for tracking SARS-CoV-2 in extrapulmonary infections in living subjects.

Hetero-aryl bromide precursor fluorine-18 radiosynthesis and preclinical evaluation of a novel positron emission tomography (PET) tracer [18F]GSK1482160.

The purinergic P2X7 receptor (P2X7R), an ATP gated ion channel, is an important therapeutic target for various inflammatory immune and neurodegenerative diseases. A novel P2X7R targeting radiotracer GSK1482160 was radiosynthesized by hetero-aryl bromides precursor 10 with [18F]Et4NF, 20-30 % radiochemical yield, > 68 GBq/µmol specific activity, >98 % radiochemical purity. Evaluation in healthy male Sprague-Dawley rats revealed that [18F]GSK1482160 ([18F]11) was stably retained 87.81 %, 72.45 %, and 56.32 % in brain, blood and liver respectively 60-min post-injection. Ex-vivo biodistribution of [18F]11 proved that it was able to target the P2X7R in vivo and there was no defluorination in the major organs. PET/MRI imaging and autoradiography revealed that [18F]11 was able to penetrate the blood-brain barrier (BBB) and to be a promising P2X7R PET radioligand for clinical translation.

Application of Dynamic 18F-FDG PET/CT for Distinguishing Intrapulmonary Metastases from Synchronous Multiple Primary Lung Cancer.

It has been a big challenge to distinguish synchronous multiple primary lung cancer (sMPLC) from primary lung cancer with intrapulmonary metastases (IPM). We aimed to assess the clinical application of dynamic 18F-FDG PET/CT in patients with multiple lung cancer nodules. We enrolled patients with multiple pulmonary nodules who had undergone dynamic 18F-FDG PET/CT and divided them into sMPLC and IPM groups based on comprehensive features. The SUVmax, fitted K i value based on dynamic scanning, and corresponding maximum diameter (D max) from the two largest tumors were determined in each patient. We determined the absolute between-tumor difference of SUVmax/D max and K i /D max (ΔSUVmax/D max; ΔK i /D max) and assessed the between-group differences. Further, the diagnostic accuracy was evaluated by ROC analysis and the correlation between ΔSUVmax/D max and ΔK i /Dmax from all groups was determined. There was no significant difference for ΔSUVmax/D max between the IPM and sMPLC groups, while the IPM group had a significantly higher ΔK i /Dmax than the sMPLC group. The AUC of ΔK i /D max for differentiating sMPLC from IPM was 0.80 (cut-off value of K i = 0.0059, sensitivity 79%, specificity 75%, p < 0.001). There was a good correlation (Pearson r = 0.91, 95% CI: 0.79-0.96, p < 0.0001) between ΔSUVmax/D max and ΔK i /D max in the IPM group but not in the sMPLC group (Pearson r = 0.45, p > 0.05). Dynamic 18F-FDG PET/CT could be a useful tool for distinguishing sMPLC from IPM. K i calculation based on Patlak graphic analysis could be more sensitive than SUVmax in discriminating IPM from sMPLC in patients with multiple lung cancer nodules.

Loss-of-function Mutations K11E or E271K Lead to Novel Tumor Suppression, Implicate Nucleolar Helicase DDX24 Oncogenicity.

Purpose: Mutations (K11E or E271K) of DEAD-box RNA helicase 24 (DDX24) were related to multi-organ venous lymphatic malformation syndrome (MOVLD). However, the relationship between these mutations and DDX24-function still remains unknown. Understanding whether K11E and E271K cause "loss-of-function" or "gain-of-function" for DDX24 is significant for related diseases. DDX24 was reported to be related to tumors closely, thus this study aims to explore how K11E and E271K affect DDX24-function in tumor proliferation. Methods: Cell lines stably expressing wild-type DDX24, K11E-DDX24, E271K-DDX24, along with vector only based on Chinese hamster ovary cells (CHO) and Balb/c tumor-bearing mice models were constructed. Then immunofluorescence staining, proliferation assay and colony formation assay in vitro and 18F-FDG PET/CT-scan were performed. Finally, the tumor tissues were collected to perform transcriptome sequencing to predict the potential mechanism. Results: Contrasted with CHO-WT-DDX24, CHO-K11E-DDX24 or CHO-E271K-DDX24 showed a decreased number of nucleoli, a slower proliferation rate and a lower colony formation rate significantly. Moreover, mice, inoculated with CHO-K11E-DDX24 or CHO-E271K-DDX24 cells, showed lower tumor formation rate, slower tumor growth rate, better prognosis, reduced standard uptake value and Ki of glucose in subcutaneous tumors. Sequencing indicated CHO-K11E-DDX24 or CHO-E271K-DDX24 caused increasing expression of TNF or chemokines and alteration in immune-related signal pathways. Conclusion: K11E or E271K mutation could lead to "loss-of-function" of DDX24 in cell proliferation and tumor bearing mice, which may be acted by non-specific immune killing to inhibit tumor growth.

A Boronated Derivative of Temozolomide Showing Enhanced Efficacy in Boron Neutron Capture Therapy of Glioblastoma.

There is an incontestable need for improved treatment modality for glioblastoma due to its extraordinary resistance to traditional chemoradiation therapy. Boron neutron capture therapy (BNCT) may play a role in the future. We designed and synthesized a 10B-boronated derivative of temozolomide, TMZB. BNCT was carried out with a total neutron radiation fluence of 2.4 ± 0.3 × 1011 n/cm2. The effects of TMZB in BNCT were measured with a clonogenic cell survival assay in vitro and PET/CT imaging in vivo. Then, 10B-boronated phenylalanine (BPA) was tested in parallel with TMZB for comparison. The IC50 of TMZB for the cytotoxicity of clonogenic cells in HS683 was 0.208 mM, which is comparable to the IC50 of temozolomide at 0.213 mM. In BNCT treatment, 0.243 mM TMZB caused 91.2% ± 6.4% of clonogenic cell death, while 0.239 mM BPA eliminated 63.7% ± 6.3% of clonogenic cells. TMZB had a tumor-to-normal brain ratio of 2.9 ± 1.1 and a tumor-to-blood ratio of 3.8 ± 0.2 in a mouse glioblastoma model. BNCT with TMZB in this model caused 58.2% tumor shrinkage at 31 days after neutron irradiation, while the number for BPA was 35.2%. Therefore, by combining the effects of chemotherapy from temozolomide and radiotherapy with heavy charged particles from BNCT, TMZB-based BNCT exhibited promising potential for therapeutic applications in glioblastoma treatment.

[Clinical analysis of 31 patients with sinonasal neuroendocrine carcinoma].

Objective:To investigate the characteristics and prognostic factors of sinonasal neuroendocrine carcinoma （SNEC）. Methods:The clinical data of 31 patients with SNEC were retrospectively analyzed. Among the 31 patients, 3 cases were simply surgically removed, 4 cases were surgery + radiotherapy, 4 cases were surgery + chemotherapy, 10 cases were surgery + chemoradiotherapy, and 10 cases were simply given chemoradiotherapy without surgery. The study follow-up 8-64 months. Results:By the end of follow-up, 2 patients were lost to follow-up, 17 died, 12 survival, 8 relapsed and 5-year survival rate was 36.4％. High TNM stage, lymph node metastasis, skull base infiltration and Ki-67≥55％ were the negative prognostic factors for survival. Conclusion:SNEC is a rare aggressive tumor, with poor prognosis, high local recurrence rate, metastasis tendency, hidden disease. The comprehensive treatment of surgery combined with chemoradiotherapy is still the best treatment.

The Role of Pretreatment 18F-FDG PET/CT for Early Prediction of Neoadjuvant Chemotherapy Response in Patients with Locoregionally Advanced Nasopharyngeal Carcinoma.

INTRODUCTION: To evaluate the role of maximal standardized uptake values (SUVmax) and total lesion glycolysis (TLG) from serial 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for early prediction of neoadjuvant chemotherapy (NAC) response in locoregionally advanced nasopharyngeal carcinoma (LANPC). METHODS: A total of 121 LANPC patients who completed pretreatment 18F-FDG PET/CT between June 2017 and July 2020 were retrospectively included. The median age of all the participants was 50 years old (range: 19-74 years), with 94 (77.7%) males and 27 (22.3%) females. The SUVmax from the primary tumor site (SUVmax-PT) and the total lesion glycolysis from the primary tumor site (TLG-PT) were recorded. Tumor response was calculated according to the Response Evaluation Criteria in Solid Tumor (RECIST) 1.1 Criteria at two-week post-secondary NAC cycle. Patients who achieved an objectively partial or full reaction after two cycles of NAC were defined as 'responders', and patients who obtained stability or progression were classified as 'non-responders'. RESULTS: After two cycles of NAC, 96 patients were categorized as "responders" and 25 patients as "non-responders". The optimal thresholds of the SUVmax-PT were 11.8 and 38.5 for the TLG-PT. Non-responders were significantly associated with high SUVmax-PT (HR, 3.49; 95% CI, 1.17-10.36; p = 0.024) and TLG-PT (HR, 4.45; 95% CI, 1.44-13.78; p = 0.010) in multivariate analysis. Recursive partitioning analysis (RPA) categorized patients into three prognostic groups based on SUVmax-PT and TLG-PT: high-response group, intermediate-response group, and low-response group, with corresponding favorable response rates of 94%, 80%, and 55%, respectively. Moreover, a nomogram was created based on metabolic parameters that precisely projected an individual's response of NAC (C-index, 0.787; 95% CI, 0.533-1.000). CONCLUSION: Pretreatment 18F-FDG PET/CT to measure SUVmax-PT and TLG-PT could be a useful non-invasive method for early indication of NAC efficacy. The nomogram based on PET/CT parameters may potentially provide direction for treatment decisions based on NAC levels.

Preclinical Evaluation of [64Cu]NOTA-CP01 as a PET Imaging Agent for Metastatic Esophageal Squamous Cell Carcinoma.

Targeting metastatic esophageal squamous cell carcinoma (ESCC) has been a challenge in clinical practice. Emerging evidence demonstrates that C-X-C chemokine receptor 4 (CXCR4) highly expresses in ESCC and plays a pivotal role in the process of tumor metastasis. We developed a copper-64 (t1/2 = 12.7 h, 19% beta+) labeling route of NOTA-CP01 derived from LY2510924, a cyclopeptide-based CXCR4 potent antagonist, in an attempt to noninvasively visualize CXCR4 expression in metastatic ESCC. Precursor NOTA-CP01 was designed by modifying the C-terminus of LY2510925 with bis-t-butyl NOTA via a butane-1,4-diamine linker. The radiolabeling process was finished within 15 min with high radiochemical yield (>95%), radiochemical purity (>99%), and specific activity (10.5-21 GBq/µmol) (non-decay-corrected). The in vitro solubility and stability tests revealed that [64Cu]NOTA-CP01 had a high water solubility (log P = -3.44 ± 0.12, n = 5) and high stability in saline and fetal bovine serum. [64Cu]NOTA-CP01 exhibited CXCR4-specific binding with a nanomolar affinity (IC50 = 1.61 ± 0.96 nM, Kd = 0.272 ± 0.14 nM) similar to that of the parental LY2510924. The in vitro cell uptake assay indicated that the [64Cu]NOTA-CP01-selective accumulation in EC109 cells was CXCR4-specific. Molecular docking of the CXCR4/NOTA-CP01 complex suggested that the Lys, Arg, and NOTA of this ligand have a strong polar interaction with the key residues of CXCR4, which explains the tight affinity of [64Cu]NOTA-CP01 for CXCR4. To test the target engagement in vivo, prolonged-time positron emission computed tomography (PET) imaging was performed at 0.5, 4, 6, 8, 12, 16, and 24 h postinjection of [64Cu]NOTA-CP01 to the EC109 tumor-bearing mice. The EC109 tumors were most visible with high contrast to the contralateral background at 6 h postinjection. The tracer revealed receptor-specific tumor accumulation, which was illustrated by effective blocking via coinjection with a blocking dose of LY2510924. Quantification analysis of the prolonged-time images showed that there was obvious radioactivity accumulation in the tumor (1.27 ± 0.19%ID/g) with the best tumor-to-blood ratio (4.79 ± 0.06) and tumor-to-muscle ratio (15.44 ± 2.94) at 6 h postinjection of the probe. The immunofluorescence and immunohistochemistry confirmed the positive expression of CXCR4 in the EC109 tumor and ESCC and metastatic lymph nodes of patients, respectively. We concluded that [64Cu]NOTA-CP01 possessed a very high target engagement for CXCR4-positive ESCC and could be a potential candidate in the clinical detection of metastatic ESCC.

Quantitative immunohistochemistry (IHC) analysis of biomarker combinations for human esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous carcinoma (ESCC) is one of the most common cancers in developing countries. However, currently there are no specific biomarkers for ESCC. This study evaluated the expression of proliferating cell nuclear antigen (PCNA), tumor suppressor protein p53, epidermal growth factor receptor (EGFR), and vascular endothelial growth factor (VEGF) as biomarkers for ESCC. METHODS: This study included 60 clinical cases (30 ESCC and 30 non-ESCC cases that were confirmed pathologically). The expression of PCNA, p53, EGFR, and VEGF were investigated using a quantitative computerized immunohistochemistry (IHC) method. The expression level of each protein was indicated by a H-score from the quantitative analysis. Receiver operating characteristic curve (ROC) and area under curve (AUC) analyses were performed. The sensitivity and specificity of each individual protein and combinations of the proteins were calculated. RESULTS: The H-score analysis indicated that expressions of EGFR, PCNA, and VEGF were statistically significantly higher in ESCC than non-ESCC patients; however, p53 was not. The panels of combinations of these proteins were more sensitive than that of any single protein. In the triplicate combination, the AUC prediction probability increased to 0.86, while the single protein AUC prediction probabilities were 0.74 (EGFR), 0.80 (PCNA), and 0.70 (VEGF). CONCLUSIONS: The high expression of PCNA, EGFR, and VEGF suggests that they are potential biomarkers for ESCC. The combination of these biomarkers may provide targets for molecular therapy and molecular imaging.

Noninvasively visualize the expression of LAPTM4B protein using a novel 18F-labeled peptide PET probe in hepatocellular carcinoma.

OBJECTIVE: Lysosomal protein transmembrane 4 beta (LAPTM4B) is selectively expressed in hepatocellular carcinoma (HCC) cells and thus a potential biomarker for diagnosing HCC. In this study, we designed a novel 18F-labeled PET probe to non-invasively visualize LAPTM4B expression in mouse model of HCC tumor. METHODS: A PET targeting tracer named [18F]FP-LAP2H was radio-synthesized using a LAPTM4B targeting peptide, LAP2H, coupled with 4-nitrophenyl-2-[18F]fluoropropionate ([18F]NFP). Radio-stability, cell uptake, micro PET/CT imaging and ex vivo biodistribution were performed for determining its stability, cell binding specificity, and tumor targeting in vivo. RESULTS: [18F]FP-LAP2H was successfully synthesized with radiochemical yields of 6-14% (decay-corrected yield) and molar activity of 10-44 GBq/µmol. The tracer showed stable (~90%) in phosphate-buffered saline, pH 7.4, and in human serum (~80%) for 2 h. In vitro cell uptake studies indicated the radioactivity accumulation in HCC cells was LAPTM4B protein-specific. Micro PET/CT demonstrated that implanted LAPTM4B positive HepG2 and BEL7402 tumors could be clearly visualized. The ex vivo biodistribution studies demonstrated that the tumor/liver ratio were 1.80 ± 0.65 and 2.09 ± 0.68 in implanted HepG2 and BEL7402 tumors respectively. Negative control and blocking experiments revealed that the radioactivity uptake in the HCC tumor was LAPTM4B protein-specific. CONCLUSIONS: [18F]FP-LAP2H appears to be a potential PET tracer for imaging LAPTM4B-positive HCC tumor. Further endeavors need to do to improve tumor/liver ratio.

Molecular PET/CT Profiling of ACE2 Expression In Vivo: Implications for Infection and Outcome from SARS-CoV-2.

Rapid progress has been made to identify and study the causative agent leading to coronavirus disease 2019 (COVID-19) but many questions including who is most susceptible and what determines severity remain unanswered. Angiotensin-converting enzyme 2 (ACE2) is a key factor in the infection process of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In this study, molecularly specific positron emission tomography imaging agents for targeting ACE2 are first developed, and these novel agents are evaluated in vitro, in preclinical model systems, and in a first-in-human translational ACE2 imaging of healthy volunteers and a SARS-CoV-2 recovered patient (NCT04422457). ACE2 expression levels in different organs in live subjects are quantitatively delineated and observable differences are measured in the patient recovered from COVID-19. Surprising sites of uptake in the breast, reproductive system and very low uptake in pulmonary tissues are reported. This novel method can add a unique tool to facilitate SARS-CoV-2 related research and improve understanding of this enigmatic disease. Molecular imaging provides quantitative annotation of ACE2, the SARS-CoV-2 entry receptor, to noninvasively monitor organs impacted by the COVID-19.

Metformin and oxyphotodynamic therapy as a novel treatment approach for triple-negative breast cancer.

BACKGROUND: Treatment for triple-negative breast cancer (TNBC) remains a significant challenge due to a lack of targeted therapies. While photodynamic therapy (PDT) has been utilized as a treatment approach for several types of cancer, oxyphotodynamic therapy (OPDT) is a novel method that improves treatment efficacy by increasing local oxygen concentration. Metformin (MET) has been demonstrated utility as an anti-tumor agent by acting through the adenosine monophosphate-activated protein kinase (AMPK) pathway. We hypothesized that MET in combination with heme, a byproduct of 5-aminolevulinic acid (ALA), may increase cytotoxicity for cancer treatment. This study aimed to investigate the synergistic effect of MET and ALA with PDT or OPDT on TNBC tumorigenic cells. METHODS: The treatment efficacy and phototoxicity of PDT or OPDT were determined using a cell viability assay. PDT/OPDT experiments were carried out in nine groups based on different combinations and concentrations of ALA and/or MET. To calculate the synergistic effect by compuSyn soft for different groups, cells were incubated with ALA and/or MET at the following concentrations (0, 0.25, 0.5,1, 2, 4, 8, 16, 24, and 32 mM). The fluorescence of ALA-induced protoporphyrin IX (PpIX) and MitoTracker Green were observed under a confocal microscope. RESULTS: The optimized therapeutic concentration ratio of ALA and MET was determined to be 1:1. The inhibition of cancer growth (IC50) for each group was 14.03, 10.62, 7.71, 18.27, 22.09, 23.96, 4.57, 10.20, and 8.18 mM, respectively. The combination index (CI) values (fa =0.5) of the last three combination groups (groups 7, 8, and 9) were 0.44, 1.70, and 1.47, respectively. PpIX fluorescence intensity of group 9 (ALA-MET-OPDT group) remained the highest among all groups, indicating an enhanced therapeutic effect. CONCLUSIONS: This study introduces OPDT as a novel anti-tumor therapy for TNBC. Furthermore, the combined use of ALA and MET had a synergistic anti-tumor effect in TNBC cells when combined with OPDT.

[Clinical analysis of 35 cases of adult rhabdomyosarcoma of nasal cavity and sinuses].

Objective:To investigate the clinical characteristics and prognostic factors of adult rhabdomyosarcoma（RMS） of nasal cavity and sinus. Method:There were 35 adult patients with RMS, including 22 with embryonal type and 13 with acinar type. Surgery + chemoradiotherapy（17 cases）, surgery + radiotherapy（6 cases）, surgery + chemotherapy（7 cases）（4 cases of seed implantation after surgery and chemotherapy）; Five patients were treated with antitumor drugs instead of surgery. Result:The study follow-up 9-62 months, adult nasal sinuses RMS total 5 years survival rate was 2.9%, among them the IRS stage>Ⅱ period, the infiltration of the skull base tumor, local lymph node metastasis, tumor diameter of 5 cm or more, 50% or higher Ki-67 are poor prognosis factor. Conclusion:RMS in nasal cavity and sinus are mostly embryonal type in adults, and the 5-year overall survival rate is low, which is related to larger primary tumor volume, local lymph node metastasis, skull base infiltration and higher ki-67 ratio at the first diagnosis in adults.

The origin, transmission and clinical therapies on coronavirus disease 2019 (COVID-19) outbreak - an update on the status.

An acute respiratory disease, caused by a novel coronavirus (SARS-CoV-2, previously known as 2019-nCoV), the coronavirus disease 2019 (COVID-19) has spread throughout China and received worldwide attention. On 30 January 2020, World Health Organization (WHO) officially declared the COVID-19 epidemic as a public health emergency of international concern. The emergence of SARS-CoV-2, since the severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002 and Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, marked the third introduction of a highly pathogenic and large-scale epidemic coronavirus into the human population in the twenty-first century. As of 1 March 2020, a total of 87,137 confirmed cases globally, 79,968 confirmed in China and 7169 outside of China, with 2977 deaths (3.4%) had been reported by WHO. Meanwhile, several independent research groups have identified that SARS-CoV-2 belongs to ß-coronavirus, with highly identical genome to bat coronavirus, pointing to bat as the natural host. The novel coronavirus uses the same receptor, angiotensin-converting enzyme 2 (ACE2) as that for SARS-CoV, and mainly spreads through the respiratory tract. Importantly, increasingly evidence showed sustained human-to-human transmission, along with many exported cases across the globe. The clinical symptoms of COVID-19 patients include fever, cough, fatigue and a small population of patients appeared gastrointestinal infection symptoms. The elderly and people with underlying diseases are susceptible to infection and prone to serious outcomes, which may be associated with acute respiratory distress syndrome (ARDS) and cytokine storm. Currently, there are few specific antiviral strategies, but several potent candidates of antivirals and repurposed drugs are under urgent investigation. In this review, we summarized the latest research progress of the epidemiology, pathogenesis, and clinical characteristics of COVID-19, and discussed the current treatment and scientific advancements to combat the epidemic novel coronavirus.