Synthesis and preclinical evaluation of 68Ga-labeled PSMA tracers with improved pharmacological properties.

Prostate cancer (PCa) is one of the most common tumors in men, with the overexpression of prostate-specific membrane. In this study, we developed four new 68Ga-labeled PSMA-targeting tracers by introducing quinoline, phenylalanine and decanoic acid groups to enhance their lipophilicity, strategically limiting their metabolic pathway through the urinary system. Four radiotracers were synthesized with radiochemical purity >95 %, and exhibited high stability in vivo and in vitro. The inhibition constants (Ki) of SDTWS01-04 to PSMA were in the nanomolar range (<10 nM). Micro PET/CT imaging and biodistribution analysis revealed that 68Ga-SDTWS01 enabled clear tumor visualization in PET images at 1.5 h post-injection, with excellent pharmacokinetic properties. Notably, the kidney uptake of 68Ga-SDTWS01 significantly reduced, with higher tumor-to-kidney ratio (0.36 ± 0.02), tumor-to-muscle ratio (24.31 ± 2.10), compared with 68Ga-PSMA-11 (T/K: 0.15 ± 0.01; T/M: 14.97 ± 1.40), suggesting that 68Ga-SDTWS01 is a promising radiotracer for the diagnosis of PCa. Moreover, SDTWS01 with a chelator DOTA could also label 177Lu and 225Ac, which could be used for the treatment of PCa.

Evaluation of a novel General Education Courses on Radiation Protection for Undergraduates.

ABSTRACT: Objective: To evaluate the effectiveness of a general education course titled "The Basis of Radiation Protection" in building and strengthening undergraduate awareness of radiation safety and cultivating innovative individuals with reasonable knowledge structures and strong practical abilities. Methods: All students from 2021 to 2022 enrolled in the core general education course "The Basis of Radiation Protection" at Shandong University of China were invited to participate. A questionnaire survey was conducted to determine changes in the students' basic cognition of radiation safety and scientific protection before and after the course. Results: The survey indicated that the cognitive level of radiation science protection had significantly improved through course completion. The Liszt quantification score range increased from 3.45 to 4.77 to 4.81 to 4.98 (p < 0.001). Further analysis revealed that different professional backgrounds significantly affected students' understanding of radiation safety protection; medical students were superior to electrical engineering students in their knowledge of ionizing radiation before the course (p < 0.001). However, after course completion, the understanding of students from both majors regarding radiation safety had relatively improved, and no significant difference was detected (p > 0.05). Feedback on the course showed that the awareness of "daily radiation protection" had significantly improved (96.8%), pseudoscience and pseudo-information could be correctively identified (93.6%), "nuclear power"-related fears had been dispelled (95.7%), and the concept of "cherishing life" had been effectively established (91.5%). Conclusion: The course effectively improved the awareness of radiation safety, strengthened the knowledge system, and provided a new way to cultivate innovative talent with reasonable knowledge structures.

Development and first-in-human study of PSMA-targeted PET tracers with improved pharmacokinetic properties.

PURPOSE: A series of new 68Ga-labeled tracers based on [68Ga]Ga-PSMA-617 were developed to augment the tumor-to-kidney ratio and reduce the activity accumulation in bladder, ultimately minimize radiation toxicity to the urinary system. METHODS: We introduced quinoline group, phenylalanine and decanoic acid into different tracers to enhance their lipophilicity, strategically limiting their metabolic pathway through the urinary system. Their binding affinity onto LNCaP cells was determined through in vitro saturation assays and competition binding assays. In vivo metabolic study, PET imaging and biodistribution experiment were performed in LNCaP tumor-bearing B-NSG male mice. The most promising tracer was selected for first-in-human study. RESULTS: Four radiotracers were synthesized with radiochemical purity (RCP) > 95% and molar activity in a range of 20.0-25.5 GBq/µmol. The binding affinities (Ki) of TWS01, TWS02 to PSMA were in the low nanomolar range (< 10 nM), while TWS03 and TWS04 exhibited binding affinities with Ki > 20 nM (59.42 nM for TWS03 and 37.14 nM for TWS04). All radiotracers exhibited high stability in vivo except [68Ga]Ga-TWS03. Micro PET/CT imaging and biodistribution analysis revealed that [68Ga]Ga-TWS02 enabled clear tumor visualization in PET images at 1.5 h post-injection, with higher tumor-to-kidney ratio (T/K, 0.93) and tumor-to-muscle ratio (T/M, 107.62) compared with [68Ga]Ga-PSMA-617 (T/K: 0.39, T/M: 15.01) and [68Ga]Ga-PSMA-11 (T/K: 0.15, T/M: 24.00). In first-in-human study, [68Ga]Ga-TWS02 effectively detected PCa-associated lesions including primary and metastatic lesions, with lower accumulation in urinary system, suggesting that [68Ga]Ga-TWS02 might be applied in the detection of bladder invasion, with minimized radiation toxicity to the urinary system. CONCLUSION: Introduction of quinoline group, phenylalanine and decanoic acid into different tracers can modulate the binding affinity and pharmacokinetics of PSMA in vivo. [68Ga]Ga-TWS02 showed high binding affinity to PSMA, excellent pharmacokinetic properties and clear imaging of PCa-associated lesions, making it a promising radiotracer for the clinical diagnosis of PCa. Moreover, TWS02 with a chelator DOTA could also label 177Lu and 225Ac, which could be used for PCa treatment without significant side effects. TRIAL REGISTRATION: The clinical evaluation of this study was registered On October 30, 2021 at https://www.chictr.org.cn/ (No: ChiCTR2100052545).

68Ga labeled EphA2-targeted cyclic peptide: a novel positron imaging tracer for triple-negative breast cancer?

The absence of better biomarkers currently limits early diagnosis and treatment of triple-negative breast cancer (TNBC). Our previously published study reported that the cyclic-peptide SD01 exhibited specific binding to EphA2 (Ephrin type-A receptor 2) on TNBC. To develop a novel PET imaging agent, we prepared gallium-68 (68Ga) labeled-DOTA-SD01 and evaluated its specificity and effectiveness through micro PET/CT imaging in a TNBC-bearing mouse model. SD01 and a control linear peptide YSA were conjugated to DOTA and subsequently labeled with 68Ga, obtaining 68Ga-DOTA-SD01 and 68Ga-DOTA-YSA. Both showed high radiochemical purity, stability, good hydrophilicity, and high binding affinity to 4T1 cells. Micro PET/CT imaging showed high radioactivity accumulation in tumors; SUVmean (mean standardized uptake value) of tumors in the group of 68Ga-DOTA-SD01 was 3.34 ± 0.25 and 2.65 ± 0.32 in the group of 68Ga-DOTA-YSA; T/NT ratios (target to non-target, SUVmean ratios of tumor to muscle) were 3.12 ± 0.06 and 2.77 ± 0.11 at 30 min, respectively (p < 0.05). The biodistribution study showed that tumor uptake % ID per g (percentage of injected dose per gram of tissue) in the group of 68Ga-DOTA-SD01 was 2.73 ± 0.34, and 1.77 ± 0.38 in the group of 68Ga-DOTA-YSA; T/NT ratios (radioactivity of tumor to muscle) were 3.55 ± 0.12 and 3.05 ± 0.10 for both groups at 30 min, respectively (p < 0.05). All these suggest that 68Ga-DOTA-SD01 may act as a better novel PET imaging agent for EphA2 positive tumors, such as TNBC.

Pentatricopeptide Repeat Gene-Mediated Mitochondrial RNA Editing Impacts on Rice Drought Tolerance.

Mitochondrial RNA editing plays crucial roles in the plant development and environmental adaptation. Pentatricopeptide repeat (PPR) genes, which are involved in the regulating mitochondrial RNA editing, are potential gene resources in the improvement of rice drought tolerance. In this study, we investigated genome-wide mitochondrial RNA editing in response to drought between upland and lowland rice. Responses of mitochondrial RNA editing to drought exhibit site-specific and genotype-specific patterns. We detected 22 and 57 ecotype-differentiated editing sites under well-watered and drought-treated conditions, respectively. Interestingly, the RNA editing efficiency was positively correlated with many agronomic traits, while it was negatively correlated with drought tolerance. We further selected two mitochondrial-localized PPR proteins, PPR035 and PPR406, to validate their functions in drought tolerance. PPR035 regulated RNA editing at rps4-926 and orfX-406, while PPR406 regulated RNA editing at orfX-355. The defectiveness in RNA editing at these sites had no apparent penalties in rice respiration and vegetative growth. Meanwhile, the knockout mutants of ppr035 and ppr406 show enhanced drought- and salt tolerance. PPR035 and PPR406 were under the balancing selection in upland rice and highly differentiated between upland and lowland rice ecotypes. The upland-dominant haplotypes of PPR035 and PPR406 shall contribute to the better drought tolerance in upland rice. They have great prospective in the improvement of rice drought tolerance.

CD93 in macrophages: A novel target for atherosclerotic plaque imaging?

Noninvasive imaging atherosclerotic (AS) plaque is of great importance for early diagnosis. Recently, CD93 in MΦ was linked to atherosclerosis development. Herein, we have investigated whether CD93 in MΦ is a potential novel target for atherosclerotic plaque imaging. CD93hi and CD93lo MΦ were prepared with or without LPS stimulation, before biological activity was evaluated. A rat AS model was produced with left carotid artery clamped. Whole-body/ex vivo phosphor autoradiography of the artery and biodistribution were investigated after incorporation of 3 H-2-DG into CD93hi and CD93lo MΦ or after 125 I-α-CD93 (125 I-anti-CD93mAb) injection. The plaque tissue was subjected to CD93/CD68 immunofluorescence/immunohistochemistry staining. CD93hi and CD93lo MΦ cells were successfully prepared without significant effect on bioactivity after incorporative labelled with 3 H-2-DG. The AS model was successfully established. Biodistribution studies showed that adoptive transfer of 3 H-2-DG-CD93hi MΦ or 125 I- α-CD93 injection resulted in accumulation of radioactivity within the atherosclerotic plaque in the clamped left carotid artery. T/NT (target/non-target, left/right carotid artery) ratio was higher in the 3 H-2-DG-CD93hi MΦ adoptive transfer group than in the 3 H-2-DG-CD93lo MΦ group (p < .05). Plaque radioactivity in the 125 I-α-CD93 injection group was significantly higher than in the 125 I-IgG control group (p < .01). The higher radioactivity accumulated in the clamped left carotid artery was confirmed by phosphor autoradiography. More importantly, CD93/CD68 double-positive MΦ accumulated at the atherosclerotic plaque in 3 H-2-DG-CD93hi MΦ adoptive transfer group, which correlated with plaque radioactivity (r = .99, p < .01). In summary, both adoptive-transferred 3 H-2-DG-labelled CD93hi MΦ and 125 I-α-CD93 injection specifically targeted CD93 in atherosclerotic plaque. CD93 is a potential target in atherosclerotic plaque imaging.

Performance and Nanostructure Simulation of Phosphogypsum Modified by Sodium Carbonate and Alum.

This paper presents a new modification of the nanostructure of CaSO4·2H2O crystals containing nanopores. This nanoporous structure was achieved in phosphogypsum samples that were modified by sodium carbonate and alum. The effects of sodium carbonate and alum on the properties of phosphogypsum were studied. X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods were used to explore the micro-mechanism of the composite system. Subsequently, molecular dynamics simulations were used to study the nanopore structures of the modified CaSO4·2H2O. The results show that the addition of sodium carbonate and alum reduced the absolute dry density by 23.1% compared with the original phosphogypsum sample, with a bending strength of 2.1 MPa and compressive strength of 7.5 MPa. In addition, new hydration products, sodium sulfate and sodium aluminum sulfate, were formed in the sample doped with sodium carbonate and alum. A new nanostructure of CaSO4·2H2O crystal containing nanopores was formed. Molecular simulations show that the hydration products were responsible for the surface nanopore formation, which was the main factor leading to an increase in mechanical strength. The presented nanopore structure yields lightweight and high strength properties in the modified phosphogypsum.

Down-Regulation of Toll-Like Receptor 5 (TLR5) Increased VEGFR Expression in Triple Negative Breast Cancer (TNBC) Based on Radionuclide Imaging.

In this study, GFP-tagged TNBC 4T1 cells with down-regulated TLR5 expression (TLR5- 4T1) and normal TLR5 expression (TLR5+ 4T1) were constructed, respectively. RT-PCR and Western blot studies showed that down-regulation of TLR5 obviously increased the expression of VEGFR in 4T1 cells. Highly stable radio-probes 125I-anti-TLR5 mAb/125I-VEGF/125I-IgG were obtained with labeling rates over 85% and radiochemical purities above 90%. Among these three probes, 125I-anti-TLR5 mAb and 125I-VEGF were used for specifically imaging TNBC, while 125I-IgG was used for comparison. Whole-body phosphorus autoradiography showed clear imaging at 48 h after injection of 125I-anti-TLR5 mAb and 125I-VEGF also provided clear imaging at 24 h. Biodistribution study demonstrated a higher tumor uptake of 125I-anti-TLR5 mAb in TLR5+ group compared with that in TLR5- group (P < 0.05), whereas tumor uptake of 125I-VEGF in TLR5+ group was lower than that in the TLR5- group (P < 0.05). Immunohistochemical staining suggested that the expression of TLR5 was lower, whereas the expression of VEGFR, CD31, and MVD (microvessel density) was higher in TLR5- tumor-bearing mice. In summary, the down-regulation of TLR5 in TNBC promoted the VEGFR expression and angiogenesis, resulting in the proliferation of TNBC cells. TLR5/VEGF might be a better indicator for monitoring the development of TNBC.

1,2,3-Triazole-Containing Compounds as Anti-Lung Cancer Agents: Current Developments, Mechanisms of Action, and Structure-Activity Relationship.

Lung cancer is the most common malignancy and leads to around one-quarter of all cancer deaths. Great advances have been achieved in the treatment of lung cancer with novel anticancer agents and improved technology. However, morbidity and mortality rates remain extremely high, calling for an urgent need to develop novel anti-lung cancer agents. 1,2,3-Triazole could be readily interact with diverse enzymes and receptors in organisms through weak interaction. 1,2,3-Triazole can not only be acted as a linker to tether different pharmacophores but also serve as a pharmacophore. This review aims to summarize the recent advances in 1,2,3-triazole-containing compounds with anti-lung cancer potential, and their structure-activity relationship (SAR) together with mechanisms of action is also discussed to pave the way for the further rational development of novel anti-lung cancer candidates.

Roles of conserved residues in the receptor binding sites of human parainfluenza virus type 3 HN protein.

Human parainfluenza virus type 3 (hPIV-3) entry and intrahost spread through membrane fusion are initiated by two envelope glycoproteins, hemagglutinin-neuraminidase (HN) and fusion (F) protein. Binding of HN protein to the cellular receptor via its receptor-binding sites triggers conformational changes in the F protein leading to virus-cell fusion. However, little is known about the roles of individual amino acids that comprise the receptor-binding sites in the fusion process. Here, residues R192, D216, E409, R424, R502, Y530 and E549 located within the receptor-binding site Ⅰ, and residues N551 and H552 at the putative site Ⅱ were replaced by alanine with site-directed mutagenesis. All mutants except N551A displayed statistically lower hemadsorption activities ranging from 16.4% to 80.2% of the wild-type (wt) level. With standardization of the number of bound erythrocytes, similarly, other than N551A, all mutants showed reduced fusogenic activity at three successive stages: lipid mixing (hemifusion), content mixing (full fusion) and syncytium development. Kinetic measurements of the hemifusion process showed that the initial hemifusion extent for R192A, D216A, E409A, R424A, R502A, Y530A, E549A and H552A was decreased to 69.9%, 80.6%, 71.3%, 67.3%, 50.6%, 87.4%, 84.9% and 25.1%, respectively, relative to the wt, while the initial rate of hemifusion for the E409A, R424A, R502A and H552A mutants was reduced to 69.0%, 35.4%, 62.3%, 37.0%, respectively. In addition, four mutants with reduced initial hemifusion rates also showed decreased percentages of F protein cleavage from 43.4% to 56.3% of the wt. Taken together, Mutants R192A, D216A, E409A, R424A, R502A, Y530A, E549A and H552A may lead to damage on the fusion activity at initial stage of hemifusion, of which decreased extent and rate may be associated with impaired receptor binding activity resulting in the increased activation barrier of F protein and the cleavage of it, respectively.

Ligand recognition, unconventional activation, and G protein coupling of the prostaglandin E2 receptor EP2 subtype.

Selective modulation of the heterotrimeric G protein α S subunit-coupled prostaglandin E2 (PGE2) receptor EP2 subtype is a promising therapeutic strategy for osteoporosis, ocular hypertension, neurodegenerative diseases, and cardiovascular disorders. Here, we report the cryo-electron microscopy structure of the EP2-Gs complex with its endogenous agonist PGE2 and two synthesized agonists, taprenepag and evatanepag (CP-533536). These structures revealed distinct features of EP2 within the EP receptor family in terms of its unconventional receptor activation and G protein coupling mechanisms, including activation in the absence of a typical W6.48 "toggle switch" and coupling to Gs via helix 8. Moreover, inspection of the agonist-bound EP2 structures uncovered key motifs governing ligand selectivity. Our study provides important knowledge for agonist recognition and activation mechanisms of EP2 and will facilitate the rational design of drugs targeting the PGE2 signaling system.

Ligand recognition and allosteric regulation of DRD1-Gs signaling complexes.

Dopamine receptors, including D1- and D2-like receptors, are important therapeutic targets in a variety of neurological syndromes, as well as cardiovascular and kidney diseases. Here, we present five cryoelectron microscopy (cryo-EM) structures of the dopamine D1 receptor (DRD1) coupled to Gs heterotrimer in complex with three catechol-based agonists, a non-catechol agonist, and a positive allosteric modulator for endogenous dopamine. These structures revealed that a polar interaction network is essential for catecholamine-like agonist recognition, whereas specific motifs in the extended binding pocket were responsible for discriminating D1- from D2-like receptors. Moreover, allosteric binding at a distinct inner surface pocket improved the activity of DRD1 by stabilizing endogenous dopamine interaction at the orthosteric site. DRD1-Gs interface revealed key features that serve as determinants for G protein coupling. Together, our study provides a structural understanding of the ligand recognition, allosteric regulation, and G protein coupling mechanisms of DRD1.

Selective Bonding Effect of Heterologous Oxygen Vacancies in Z-Scheme Cu2O/SrFe0.5Ta0.5O3 Heterojunctions for Constructing Efficient Interfacial Charge-Transfer Channels and Enhancing Photocatalytic NO Removal Performances.

An interfacial structure is crucial to the photoinduced electron transport for a heterostructure photocatalyst. Constructing an interfacial electron channel with an optimized interfacial structure can efficiently improve the electron-transfer efficiency. Herein, the rapid electron-transfer channels were built up in a Cu2O/SrFe0.5Ta0.5O3 heterojunction (Cu2O/SFTO) based on the selective bonding effect of heterologous surface oxygen vacancies in the SFTO component. The heterologous surface oxygen vacancies, namely, VO-Fe and VO-Ta, respectively, adjacent to Fe and Ta atoms, were introduced into fabricating the Z-scheme Cu2O/SFTO heterojunction. Compared with sample Cu2O/SFTO with VO-Fe, the photocatalytic NO removal efficiency of sample Cu2O/SFTO with VO-Fe and VO-Ta was increased by 22.5%. The enhanced photocatalytic performance originated from the selective bonding effect of heterologous VO-Fe and VO-Ta on the interfacial electron-separating and -transfer efficiency. VO-Fe is the main body to construct the interfacial electron-transfer channels by forming interfacial Fe-O-Cu(I) bonds, which causes lattice distortion at the interface, and VO-Ta can optimize the structure of interfacial channels by balancing the electron density of SFTO to control the average space of the interface transition zone. This research provides a new cognitive perspective for constructing double perovskite oxide-based heterostructure photocatalysts.

Design, Synthesis and Anti-Lung Cancer Evaluation of 1, 2, 3-Triazole Tethered Dihydroartemisinin-Isatin Hybrids.

A series of 1,2,3-triazole tethered dihydroartemisinin-isatin hybrids 8a-c and 9a-k were designed and synthesized. Their antiproliferative activity against A549, doxorubicin-resistant A549 (A549/DOX) as well as cisplatin-resistant A549 (A549/DDP) lung cancer cell lines was also investigated in this study. All hybrids (half maximal inhibitory concentration/IC50: 7.54-73.8 µM) were more potent than the parent drug dihydroartemisinin (IC50: 69.4-88.0 µM) and also non-cytotoxic towards mouse embryonic fibroblast cells NIH/3T3 (IC50: >100 µM). The structure-activity relationships illustrated that the substituents on C-3 and C-5 position of isatin moiety influenced the activity significantly. Imine at C-3 position decreased the activity, whereas fluoro at C-5 position enhanced the activity. In particular, hybrids 8a,c (IC50: 7.54-12.1 µM) and 9i (IC50: 9.10-15.9 µM) were comparable to cisplatin (IC50: 7.54-15.9 µM vs 9.38-19.7 µM) against A549 and A549/DOX, but 4.6-7.6 folds more potent than that of cisplatin (IC50: 8.77-14.3 µM vs 66.9 µM) against A549/DDP cells. Moreover, hybrids 8a,c exhibited excellent stability (liver microsomes: 68-83%) in mouse/human microsomes and good pharmacokinetic properties, demonstrating their potential as a novel anti-lung cancer chemotherapeutic candidates.

IL-27 Rα+ cells promoted allorejection via enhancing STAT1/3/5 phosphorylation.

Recently, emerging evidence strongly suggested that the activation of interleukin-27 Receptor α (IL-27Rα) could modulate different inflammatory diseases. However, whether IL-27Rα affects allotransplantation rejection is not fully understood. Here, we investigated the role of IL-27Rα on allorejection both in vivo and in vitro. The skin allotransplantation mice models were established, and the dynamic IL-27Rα/IL-27 expression was detected, and IL-27Rα+ spleen cells adoptive transfer was performed. STAT1/3/5 phosphorylation, proliferation and apoptosis were investigated in mixed lymphocyte reaction (MLR) with recombinant IL-27 (rIL-27) stimulation. Finally, IFN-γ/ IL-10 in graft/serum from model mice was detected. Results showed higher IL-27Rα/IL-27 expression in allografted group compared that syngrafted group on day 10 (top point of allorejection). IL-27Rα+ spleen cells accelerated allograft rejection in vivo. rIL-27 significantly promoted proliferation, inhibited apoptosis and increased STAT1/3/5 phosphorylation of alloreactive splenocytes, and these effects of rIL-27 could be almost totally blocked by JAK/ STAT inhibitor and anti-IL-27 p28 Ab. Finally, higher IL-27Rα+ IFN-γ+ cells and lower IL-27Rα+ IL-10+ cells within allografts, and high IFN-γ/low IL-10 in serum of allorejecting mice were detected. In conclusion, these data suggested that IL-27Rα+ cells apparently promoted allograft rejection through enhancing alloreactive proliferation, inhibiting apoptosis and up-regulating IFN-γ via enhancing STAT pathway. Blocking IL-27 pathway may favour to prevent allorejection, and IL-27Rα may be as a high selective molecule for targeting diagnosis and therapy for allotransplantation rejection.

Monitoring Early-Stage Acute Rejection by Imaging CXCR3-Positive Cell Infiltration: Evaluation of ¹²5Iodine-Labeled CXCL10.

OBJECTIVES: It has been reported that CXCR3 is related to inflammatory cell infiltration. The purpose of this study was to investigate iodine-125-labeled CXCL10, a ligand of CXCR3, as a tracer targeting CXCR3 to detect acute rejection in a mouse skin transplant model. MATERIALS AND METHODS: The isograft and allograft skin models were established with BALB/c and C57BL/6 mouse skin, respectively, as donors and BALB/c mice as recipients. We used reverse transcriptase-polymerase chain reaction and immunochemistry staining to test CXCR3 expression. ¹²5I-labeled CXCL10 was produced with the iodogenic method. Allograft/isograft mice were examined with whole body autoradiography and ex vivo biodistribution after tail vein injection of ¹²5I-labeled CXCL10 on day 8 posttransplant. RESULTS: CXCR3 expression was higher in allograft tissue than in isograft control. ¹²5I-labeled CXCL10 was prepared with high specificity and affinity. Biodistribution results showed higher ¹²5I-labeled CXCL10 uptake in allograft tissue. The target-to-nontarget ratio was 3.01 ± 0.25 at 24 hours, a result higher than that shown in the isograft group. Pharmacokinetic analyses of ¹²5I-labeled CXCL10 showed that distribution half-life was 0.34 hour and the elimination half-life was 9.83 hours. Dynamic whole body autoradiography images of ¹²5I-labeled CXCL10 showed excellent graft visualization in the allograft compared with the isograft group at all checking points, with visualization much more obvious at 12 and 24 hours. CONCLUSIONS: These data suggest that CXCR3 is a promising imaging target for immune cell infiltration in early-stage acute rejection and ¹²5I-labeled CXCL10 can successfully image acute rejection with good pharmacokinetics.

IL-27Rα: A Novel Molecular Imaging Marker for Allograft Rejection.

Non-invasively monitoring allogeneic graft rejection with a specific marker is of great importance for prognosis of patients. Recently, data revealed that IL-27Rα was up-regulated in alloreactive CD4+ T cells and participated in inflammatory diseases. Here, we evaluated whether IL-27Rα could be used in monitoring allogeneic graft rejection both in vitro and in vivo. Allogeneic (C57BL/6 donor to BALB/c recipient) and syngeneic (BALB/c both as donor and recipient) skin grafted mouse models were established. The expression of IL-27Rα in grafts was detected. The radio-probe, 125I-anti-IL-27Rα mAb, was prepared. Dynamic whole-body phosphor-autoradiography, ex vivo biodistribution and immunofluorescence staining were performed. The results showed that the highest expression of IL-27Rα was detected in allogeneic grafts on day 10 post transplantation (top period of allorejection). 125I-anti-IL-27Rα mAb was successfully prepared with higher specificity and affinity. Whole-body phosphor-autoradiography showed higher radioactivity accumulation in allogeneic grafts than syngeneic grafts on day 10. The uptake of 125I-anti-IL-27Rα mAb in allogeneic grafts could be almost totally blocked by pre-injection with excess unlabeled anti-IL-27Rα mAb. Interestingly, we found that 125I-anti-IL-27Rα mAb accumulated in allogeneic grafts, along with weaker inflammation earlier on day 6. The high uptake of 125I-anti-IL-27Rα mAb was correlated with the higher infiltrated IL-27Rα positive cells (CD3+/CD68+) in allogeneic grafts. In conclusion, IL-27Rα may be a novel molecular imaging marker to predict allorejection.

Withdrawn: The radiosynthesis of novel PI3K inhibitor, 8-ethoxy-2-(4-[18 F] fluorophenyl)-3-nitro-2H-chromene (18 F-EFPNC).

Withdrawal: Jianfeng Liu et al. 'The radiosynthesis of novel PI3K inhibitor, 8-ethoxy-2-(4-[18 F]fluorophenyl)-3-nitro-2H-chromene (18 F-EFPNC)', Journal of Labelled Compounds and Radiopharmaceuticals (https://doi.org/10.1002/jlcr.3524). The above article, published online on 30 May 2017 on Wiley Online Library (wileyonlinelibrary.com), has been withdrawn by agreement between the journal's Editor-in-Chief Committee, and John Wiley & Sons Ltd. The withdrawal has been agreed as it was not possible to complete corrections and finalise the article.

TLR5: A prognostic and monitoring indicator for triple-negative breast cancer.

A novel, highly selective biomarker is urgently needed to predict and monitor triple-negative breast cancer (TNBC) because targeting molecules are not currently available. Although associated with various malignant tumors, the role of toll-like receptor 5 (TLR5) in TNBC remains uncertain. We aimed to define the effects of TLR5 in TNBC to determine whether it could serve as a prognostic and monitoring indicator for TNBC. We established TNBC cell line 4T1 with low TLR5 expression (GFP tag; TLR5- 4T1) and with normal TLR5 expression (GFP tag; TLR5+ 4T1) using lentivirus-shRNA-TLR5 knockdown transfection and negative lentivirus transfection, respectively. Detected by western blot and qPCR, we found knockdown of TLR5 resulted in decreased expression of TLR5 and E-cadherin and increased expression of N-cadherin, vimentin, fibronectin, TRAF6, SOX2, and Twist1, which were related to EMT (epithelial-mesenchymal transition). In addition, downregulation of TLR5 increased the invasion and migration of 4T1 cells in vitro, which were investigated by CCK-8 and wound healing, as well as transwell assay and colony formation. Furthermore, the metastatic ability of TLR5- 4T1 cells to the lungs was also increased compared to TLR5+ 4T1 cells in vivo. To verify the effect of TLR5 as a monitor indicator, mice bearing TLR5+ and TLR5- 4T1 tumors injected with 125I-anti-TLR5 mAb or isotype 125I-IgG were assessed by whole body phosphor-autoradiography and fluorescence imaging in vivo. Phosphor-autoradiography of model mice revealed early tumors at 6 days after inoculation with TLR5+ 4T1, but not TLR5- 4T1 cells. Intratumoral accumulation of radioactivity positively correlated with TLR5 expression, and fluorescence imaging in vivo revealed both TLR5+ and TLR5- 4T1 tumors. Our results suggested that downregulation of TLR5 in TNBC increased tumor invasiveness and EMT expression via TRAF6 and SOX2 pathway and TLR5 could serve as a prognostic and monitoring indicator for TLR5-positive tumors.