Objective:To develop a novel fibroblast activation protein (FAP) cyclic peptide imaging agent, Al 18F-FAP-NOX, evaluate its in vitro and in vivo properties, and explore its feasibility of PET/CT imaging in tumors with FAP positive expression. Methods:Al 18F-FAP-NOX was manually synthesized. The in vitro stability of Al 18F-FAP-NOX was determined using radio high performance liquid chromatography (HPLC). The lipid water partition coefficient log P, in vitro cell uptake experiments, microPET/CT imaging and biodistribution in 293T-FAP tumor-bearing mice were conducted to preliminarily evaluate the pharmacokinetics and biological efficacy of Al 18F-FAP-NOX. Afterwards, a patient (male, 65 years old) with lung cancer underwent Al 18F-FAP-NOX PET/CT imaging. Results:Al 18F-FAP-NOX was successfully synthesized with a yield of (26.28±2.31)% without attenuation correction ( n=4), and the radiochemical purity was more than 95%. Al 18F-FAP-NOX exhibited good stability and hydrophilicity (log P=-3.02±0.08, n=5). In cell assays, the uptake of Al 18F-FAP-NOX in HT1080-FAP cells reached the plateau phase at 15 min ((7.31±0.53) percentage activity of injection dose per million cells (%ID/mio cells)), exhibiting high cellular uptake. The uptake of Al 18F-FAP-NOX could be significantly inhibited by 1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)-FAP-2286. The microPET/CT results of 293T-FAP tumor-bearing mice in vivo showed that Al 18F-FAP-NOX was highly uptaken in FAP-positive tumor tissues (60 min: (12.47±1.66) percentage activity of injection dose per gram of tissue (%ID/g)), while the uptake was very low in FAP-negative tumors. The biodistribution results were similar to the microPET/CT imaging results of tumor-bearing mice. The human clinical imaging showed an abnormal increase in Al 18F-FAP-NOX uptake (SUV max 5.5) of the lung cancer lesions. Conclusions:A novel cyclic peptide radiopharmaceutical, Al 18F-FAP-NOX, demonstrates good stability and hydrophilicity. It can be quickly distributed to tumor tissue in vivo. The human clinical PET/CT imaging shows certain diagnostic ability of Al 18F-FAP-NOX for lung cancer lesions. It is a promising cyclic peptide agent for PET imaging.

Objective:To systematically evaluate the safety and efficacy of the novel fibroblast activation protein (FAP)-targeted tracer 64Cu-FAP inhibitor (FAPI)-XT117 in patients with malignant solid tumors, and to compare with 18F-FDG. Methods:This self-controlled study was conducted on fifteen patients (8 males, 7 females; age (60 ±9) years) with malignant solid tumors from the First Affiliated Hospital of Guangzhou Medical University between July 2023 and December 2023. Each subject underwent 64Cu-FAPI-XT117 PET/CT at 30, 60, and 120min post-injection and was assigned to three dose cohorts (111MBq, 148MBq, and 185MBq; 5 patients in each cohort), and safety assessments were conducted within 24h after injection. In addition, all patients underwent 18F-FDG PET/CT at 60min post-injection. Time-activity curves were generated for 64Cu-FAPI-XT117, and the dosimetry was calculated. Image quality was evaluated using a 5-point Likert scale, and the optimal injected activity and imaging time point were determined. The paired t test was used to compare differences of the lesion detection count and SUV max between 64Cu-FAPI-XT117 and 18F-FDG PET/CT. Results:64Cu-FAPI-XT117 was well tolerated, with no adverse events reported. Time-activity curves of 68Ga-FAPI-XT117 revealed prominent uptake in the uterus, while the background activity in other organs remained low, with the whole-body effective dose of (0.0084±0.0021)mSv/MBq. The optimal imaging time point for 64Cu-FAPI-XT117 PET/CT was 60min post-injection, with an optimal administered activity of 111MBq. Compared with 18F-FDG, 64Cu-FAPI-XT117 demonstrated significantly higher uptake and more lesions in lymph-node metastases (SUV max: 8.6±3.8 vs 15.3±6.8, t=2.33, P=0.048; number of lesions: 8.3±5.4 vs 15.0±6.4; t=4.21, P=0.003) and distant metastases (SUV max: 11.8±3.7 vs 20.9±7.2, t=3.66, P=0.022; number of lesions: 7.0±3.2 vs 12.4±3.7, t=2.86, P=0.046). Conclusions:64Cu-FAPI-XT117 PET/CT is well tolerated in patients with solid tumors, with a controllable radiation risk. Moreover, it outperforms 18F-FDG PET/CT in the assessment of metastases.

Objective:To develop a novel fibroblast activation protein (FAP) cyclic peptide imaging agent, Al 18F-FAP-NOX, evaluate its in vitro and in vivo properties, and explore its feasibility of PET/CT imaging in tumors with FAP positive expression. Methods:Al 18F-FAP-NOX was manually synthesized. The in vitro stability of Al 18F-FAP-NOX was determined using radio high performance liquid chromatography (HPLC). The lipid water partition coefficient log P, in vitro cell uptake experiments, microPET/CT imaging and biodistribution in 293T-FAP tumor-bearing mice were conducted to preliminarily evaluate the pharmacokinetics and biological efficacy of Al 18F-FAP-NOX. Afterwards, a patient (male, 65 years old) with lung cancer underwent Al 18F-FAP-NOX PET/CT imaging. Results:Al 18F-FAP-NOX was successfully synthesized with a yield of (26.28±2.31)% without attenuation correction ( n=4), and the radiochemical purity was more than 95%. Al 18F-FAP-NOX exhibited good stability and hydrophilicity (log P=-3.02±0.08, n=5). In cell assays, the uptake of Al 18F-FAP-NOX in HT1080-FAP cells reached the plateau phase at 15 min ((7.31±0.53) percentage activity of injection dose per million cells (%ID/mio cells)), exhibiting high cellular uptake. The uptake of Al 18F-FAP-NOX could be significantly inhibited by 1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)-FAP-2286. The microPET/CT results of 293T-FAP tumor-bearing mice in vivo showed that Al 18F-FAP-NOX was highly uptaken in FAP-positive tumor tissues (60 min: (12.47±1.66) percentage activity of injection dose per gram of tissue (%ID/g)), while the uptake was very low in FAP-negative tumors. The biodistribution results were similar to the microPET/CT imaging results of tumor-bearing mice. The human clinical imaging showed an abnormal increase in Al 18F-FAP-NOX uptake (SUV max 5.5) of the lung cancer lesions. Conclusions:A novel cyclic peptide radiopharmaceutical, Al 18F-FAP-NOX, demonstrates good stability and hydrophilicity. It can be quickly distributed to tumor tissue in vivo. The human clinical PET/CT imaging shows certain diagnostic ability of Al 18F-FAP-NOX for lung cancer lesions. It is a promising cyclic peptide agent for PET imaging.

Objective:To systematically evaluate the safety and efficacy of the novel fibroblast activation protein (FAP)-targeted tracer 64Cu-FAP inhibitor (FAPI)-XT117 in patients with malignant solid tumors, and to compare with 18F-FDG. Methods:This self-controlled study was conducted on fifteen patients (8 males, 7 females; age (60 ±9) years) with malignant solid tumors from the First Affiliated Hospital of Guangzhou Medical University between July 2023 and December 2023. Each subject underwent 64Cu-FAPI-XT117 PET/CT at 30, 60, and 120min post-injection and was assigned to three dose cohorts (111MBq, 148MBq, and 185MBq; 5 patients in each cohort), and safety assessments were conducted within 24h after injection. In addition, all patients underwent 18F-FDG PET/CT at 60min post-injection. Time-activity curves were generated for 64Cu-FAPI-XT117, and the dosimetry was calculated. Image quality was evaluated using a 5-point Likert scale, and the optimal injected activity and imaging time point were determined. The paired t test was used to compare differences of the lesion detection count and SUV max between 64Cu-FAPI-XT117 and 18F-FDG PET/CT. Results:64Cu-FAPI-XT117 was well tolerated, with no adverse events reported. Time-activity curves of 68Ga-FAPI-XT117 revealed prominent uptake in the uterus, while the background activity in other organs remained low, with the whole-body effective dose of (0.0084±0.0021)mSv/MBq. The optimal imaging time point for 64Cu-FAPI-XT117 PET/CT was 60min post-injection, with an optimal administered activity of 111MBq. Compared with 18F-FDG, 64Cu-FAPI-XT117 demonstrated significantly higher uptake and more lesions in lymph-node metastases (SUV max: 8.6±3.8 vs 15.3±6.8, t=2.33, P=0.048; number of lesions: 8.3±5.4 vs 15.0±6.4; t=4.21, P=0.003) and distant metastases (SUV max: 11.8±3.7 vs 20.9±7.2, t=3.66, P=0.022; number of lesions: 7.0±3.2 vs 12.4±3.7, t=2.86, P=0.046). Conclusions:64Cu-FAPI-XT117 PET/CT is well tolerated in patients with solid tumors, with a controllable radiation risk. Moreover, it outperforms 18F-FDG PET/CT in the assessment of metastases.

Nowadays potential preclinical drugs for the treatment of nonalcoholic steatohepatitis (NASH) have failed to achieve expected therapeutic efficacy because the pathogenic mechanisms are underestimated. Inactive rhomboid protein 2 (IRHOM2), a promising target for treatment of inflammation-related diseases, contributes to deregulated hepatocyte metabolism-associated nonalcoholic steatohepatitis (NASH) progression. However, the molecular mechanism underlying Irhom2 regulation is still not completely understood. In this work, we identify the ubiquitin-specific protease 13 (USP13) as a critical and novel endogenous blocker of IRHOM2, and we also indicate that USP13 is an IRHOM2-interacting protein that catalyzes deubiquitination of Irhom2 in hepatocytes. Hepatocyte-specific loss of the Usp13 disrupts liver metabolic homeostasis, followed by glycometabolic disorder, lipid deposition, increased inflammation, and markedly promotes NASH development. Conversely, transgenic mice with Usp13 overexpression, lentivirus (LV)- or adeno-associated virus (AAV)-driven Usp13 gene therapeutics mitigates NASH in 3 models of rodent. Mechanistically, in response to metabolic stresses, USP13 directly interacts with IRHOM2 and removes its K63-linked ubiquitination induced by ubiquitin-conjugating enzyme E2N (UBC13), a ubiquitin E2 conjugating enzyme, and thus prevents its activation of downstream cascade pathway. USP13 is a potential treatment target for NASH therapy by targeting the Irhom2 signaling pathway.

BACKGROUND: Unstable cases of Hangman’s fracture or traumatic spondylilisthesis which are type II, IIa and III should be treated surgicaly. Retropharyngeal approach was employed in exposure of anterior upper cervical region. However, dissection and traction around important structures make the procedure complicated and increase the chance of nerve injury.
OBJECTIVE:To evaluate the clinical curative effect and safety of an innovative operative technique in which a polyetheretherketone cage was used to perform cervical spinal fusion for the treatment of Hangman’s fracture.
METHODS: Eight patients with type II or IIa Hangman’s fracture were enroled in this study and received cervical fusions at C2/3 levels. During folow-up postoperatively, they received X-ray examination. Fusion time and implant position were evaluated. The angle of deformity (α) and the displacement distance (β) were compared pre-operatively and 6-month post-operatively to measure reduction. The functional outcomes were also compared using the Post-Traumatic Neck Score (Mayo) pre-operatively and 6-month post-operatively, while neck pain was further investigated by Visual Analogue Scale score.
RESULTS AND CONCLUSION:Al eight patients were folowed-up successfuly, with an average folow-up of 13 months (range 6-26 months). Compared with pre-operatively, Clinical Post-Traumatic Neck Score (Mayo) was increased, Visual Analogue Scale score, angle deformity (α) and displacement distance (β) were reduced at 6-month post-operatively (P < 0.05). Neck activity was not limited in final folow-up. Bone fusion was found in al patients at 3 or 6 months post-operatively, and no complication was detected. Results confirm that polyetheretherketone cage for type II and IIa Hangman’s fracture could achieve good outcomes and safety.