Clinical translation of a novel FAPI dimer [68Ga]Ga-LNC1013.

Fibroblast activation protein (FAP) has emerged as a highly promising target for cancer diagnostic imaging and targeted radionuclide therapy. To exploit the therapeutic potential of suitably radiolabeled FAP inhibitors (FAPIs), this study presents the design and synthesis of a series of FAPI dimers to increase tumor uptake and retention. Preclinical evaluation and a pilot clinical PET imaging study were conducted to screen the lead compound with the potential for radionuclide therapy. METHODS: Three new FAPI dimers were synthesized by linking two quinoline-based FAPIs with different spacers. The in vitro binding affinity and preclinical small animal PET imaging of the compounds were compared with their monomeric counterparts, FAPI-04 and FAPI-46. The lead compound, [68Ga]Ga -LNC1013, was then evaluated in a pilot clinical PET imaging study involving seven patients with gastrointestinal cancer. RESULTS: The three newly synthesized FAPI homodimers had high binding affinity and specificity in vitro and in vivo. Small animal PET imaging and biodistribution studies showed that [68Ga]Ga-LNC1013 had persistent tumor retention for at least 4 h, also higher uptake than the other two dimers and the monomer counterparts, making it the lead compound to enter clinical investigation. In the pilot clinical PET imaging study, seven patients were enrolled. The effective dose of [68Ga]Ga-LNC1013 was 8.24E-03 mSv/MBq. The human biodistribution of [68Ga]Ga-LNC1013 demonstrated prominent tumor uptake and good tumor-to-background contrast. [68Ga]Ga-LNC1013 PET imaging showed potential in capturing primary and metastatic lesions and outperforming 18F-FDG PET in detecting pancreatic and esophageal cancers. The SUVmax for lesions with [68Ga]Ga-FAPI-46 decreased over time, whereas [68Ga]Ga-LNC1013 exhibited persistently high tumor uptake from 1 to 4 h post-injection. CONCLUSION: Dimerization is an effective strategy to produce FAPI derivatives with favorable tumor uptake, long tumor retention, and imaging contrast over its monomeric counterpart. We demonstrated that [68Ga]Ga-LNC1013, the lead compound without any piperazine moiety, had superior diagnostic potential over [68Ga]Ga-FAPI-46 and 18F-FDG, suggesting the future potential of LNC1013 for radioligand therapy of FAP-positive cancers.

[68Ga]Ga-AUNP-12 PET imaging to assess the PD-L1 status in preclinical and first-in-human study.

PURPOSE: PD-L1 PET imaging, as a non-invasive procedure, can perform a real-time, dynamic and quantitative analysis of PD-L1 expression at tumor sites. In this study, we developed a novel peptide-based PET tracer, [68 Ga]Ga-AUNP-12, for preclinical and first-of-its-kind imaging of PD-L1 expression in patients. METHODS: Radiosynthesis of [68 Ga]Ga-AUNP-12 was conducted. Assays for cellular uptake and binding were conducted on the PANC02, CT26, and B16F10 cell lines. Preclinical models were used to investigate its biodistribution, imaging capacity, and pharmacokinetics. Furthermore, interferon-γ (IFN-γ) was used for development of an animal model with high PD-L1 expression for targeted PET imaging and efficacy evaluation of PD-L1 blocking therapy. In healthy volunteers and cancer patients, the PD-L1 imaging, radiation dosimetry, safety, and biodistribution were further evaluated. RESULTS: In vitro and in vivo animal studies showed that [68 Ga]Ga-AUNP-12 PET imaging displayed a high specificity in evaluating PD-L1 expression. The radiochemical yield of [68 Ga]Ga-AUNP-12 was 71.7 ± 8.2%. Additionally, its molar activity and radiochemical purity were satisfactory. The B16F10 tumor was visualized with the tumor uptake of 6.86 ± 0.71% ID/g and tumor-to-muscle ratio of 6.83 ± 0.36 at 60 min after [68 Ga]Ga-AUNP-12 injection. Furthermore, [68 Ga]Ga-AUNP-12 PET imaging could sensitively detect the PD-L1 dynamic changes in CT26 tumor xenograft models regulated by IFN-γ treatment, and correspondingly can effectively guide immunotherapy. Regarding radiation dosimetry, [68 Ga]Ga-AUNP-12 is safe for human use. The first human study found that [68 Ga]Ga-AUNP-12 can be rapidly cleared from blood and other nonspecific organs through the kidney excretion, leading to form a clear imaging contrast in the clinical framework. The specificity of [68 Ga]Ga-AUNP-12 was validated and tumor uptake strongly correlated with the high PD-L1 expression in patients with lung adenocarcinoma and oesophageal squamous cell carcinoma (OSCC). CONCLUSION: [68 Ga]Ga-AUNP-12 was successfully developed as a PD-L1-specific PET imaging tracer in preclinical and first-in-human studies.

Self-immolative nanocapsules precisely regulate depressive neuronal microenvironment for synergistic antidepression therapy.

BACKGROUND: Pharmacotherapy constitutes the first-line treatment for depression. However, its clinical use is hindered by several limitations, such as time lag, side effects, and narrow therapeutic windows. Nanotechnology can be employed to shorten the onset time by ensuring permeation across the blood brain barrier (BBB) to precisely deliver more therapeutic agents; unfortunately, formidable challenges owing to the intrinsic shortcomings of commercial drugs remain. RESULTS: Based on the extraordinary capability of monoamines to regulate the neuronal environment, we engineer a network nanocapsule for delivering serotonin (5-hydroxytryptamine, 5-HT) and catalase (CAT) to the brain parenchyma for synergistic antidepression therapy. The nanoantidepressants are fabricated by the formation of 5-HT polymerization and simultaneous payload CAT, following by surface modifications using human serum albumin and rabies virus glycoprotein. The virus-inspired nanocapsules benefit from the surface-modifying strategies and exhibit pronounced BBB penetration. Once nanocapsules reach the brain parenchyma, the mildly acidic conditions trigger the release of 5-HT from the sacrificial nanocapsule. Releasing 5-HT further positively regulate moods, relieving depressive symptoms. Meanwhile, cargo CAT alleviates neuroinflammation and enhances therapeutic efficacy of 5-HT. CONCLUSION: Altogether, the results offer detailed information encouraging the rational designing of nanoantidepressants and highlighting the potential of nanotechnology in mental health disorder therapies.

Novel hypoxia-induced HIF1α-circTDRD3-positive feedback loop promotes the growth and metastasis of colorectal cancer.

Tumor hypoxia and circular RNAs (circRNAs) are considered to play key roles in tumor progression and malignancy, respectively. Nevertheless, the biological functions and underlying mechanisms of specific circRNAs exposed to hypoxic microenvironments in colorectal cancer (CRC) remain largely elusive. Herein, a novel circRNA, circTDRD3, which is upregulated under hypoxic conditions, was identified. The expression of circTDRD3 was highly expressed in CRC tissues and positively correlated with overall survival, tumor size, lymph node invasion and clinical stage. CircTDRD3 facilitated CRC cell proliferation, migration and metastasis in vitro and in vivo. Mechanistically, circTDRD3 promoted HIF1α expression by sponging miR-1231, which facilitated CRC progression. Meanwhile, HIF1α directly combined with TDRD3 promoter to increase the expression of TDRD3 pre-mRNA. Then HIF1a-induced PTBP1 accelerated the formation of circTDRD3. Our findings reveal that circTDRD3 facilitates the proliferation and metastasis of CRC through a positive feedback loop mediated by the HIF1α/PTBP1/circTDRD3/miR-1231/HIF1α axis. Therefore, circTDRD3 may serve as a prognostic biomarker and therapeutic target for patients with CRC.

Exosomal MicroRNA signature acts as an efficient biomarker for non-invasive diagnosis of gallbladder carcinoma.

Through a three-step study that relies on biomarker discovery, training, and validation, we identified a set of five exosomal microRNAs (miRNAs) that can be used to evaluate the risk of gallbladder carcinoma (GBC), including miR-552-3p, miR-581, miR-4433a-3p, miR-496, and miR-203b-3p. When validated in 102 GBC patients and 112 chronic cholecystitis patients from multiple medical centers, the AUC of this combinatorial biomarker was 0.905, with a sensitivity of 81.37% and a specificity of 86.61%. The performance of this biomarker is superior to that of the standard biomarkers CA199 and CEA and is suited for GBC early diagnosis. The multi-clinicopathological features and prognosis of GBC patients were significantly associated with this biomarker. After building a miRNA-target gene regulation network, cell functions and signaling pathways regulated by these five miRNAs were examined. This biomarker signature can be used in the development of a noninvasive tool for GBC diagnosis, screening and prognosis prediction.

Preclinical and first-in-human evaluation of 18F-labeled D-peptide antagonist for PD-L1 status imaging with PET.

PURPOSE: PD-L1 PET imaging allows for the whole body measuring its expression across primary and metastatic tumors and visualizing its spatiotemporal dynamics before, during, and after treatment. In this study, we reported a novel 18F-labeled D-peptide antagonist, 18F-NOTA-NF12, for PET imaging of PD-L1 status in preclinical and first-in-human studies. METHODS: Manual and automatic radiosynthesis of 18F-NOTA-NF12 was performed. Cell uptake and binding assays were completed in MC38, H1975, and A549 cell lines. The capacity for imaging of PD-L1 status, biodistribution, and pharmacokinetics were investigated in preclinical models. The PD-L1 status was verified by western blotting, immunohistochemistry/fluorescence, and flow cytometry. The safety, radiation dosimetry, biodistribution, and PD-L1 imaging potential were evaluated in healthy volunteers and patients. RESULTS: The radiosynthesis of 18F-NOTA-NF12 was achieved via manual and automatic methods with radiochemical yields of 41.7 ± 10.2 % and 70.6 ± 4.2 %, respectively. In vitro binding assays demonstrated high specificity and affinity with an IC50 of 78.35 nM and KD of 85.08 nM. The MC38 and H1975 tumors were clearly visualized with the optimized tumor-to-muscle ratios of 5.36 ± 1.17 and 7.13 ± 1.78 at 60 min after injection. Gemcitabine- and selumetinib-induced modulation of PD-L1 dynamics was monitored by 18F-NOTA-NF12. The tumor uptake correlated well with their PD-L1 expression. 18F-NOTA-NF12 exhibited renal excretion and rapid clearance from blood and other non-specific organs, contributing to high contrast imaging in the clinical time frame. In NSCLC and esophageal cancer patients, the specificity of 18F-NOTA-NF12 for PD-L1 imaging was confirmed. The 18F-NOTA-NF12 PET/CT and 18F-FDG PET/CT had equivalent findings in patients with high PD-L1 expression. CONCLUSION: 18F-NOTA-NF12 was developed successfully as a PD-L1-specific tracer with promising results in preclinical and first-in-human trials, which support the further validation of 18F-NOTA-NF12 for PET imaging of PD-L1 status in clinical settings.

Preclinical and exploratory human studies of novel 68Ga-labeled D-peptide antagonist for PET imaging of TIGIT expression in cancers.

PURPOSE: While TIGIT has been propelled as a next-generation target in cancer immunotherapy, anti-TIGIT therapy seems to be promising for a fraction of patients in clinical trials. Therefore, patient stratification is critical for this therapy, which could benefit from a whole-body, non-invasive, and quantitative evaluation of TIGIT expression in cancers. In this study, a 68Ga-labeled D-peptide antagonist, 68Ga-GP12, was developed and validated for PET imaging of TIGIT expression in vitro, in vivo, and in an exploratory human study. METHODS: The D-enantiomer peptide antagonists were modified and radiolabeled with 68Ga. In vitro binding assays were performed in human peripheral blood mononuclear cells (PBMCs) to assess their affinity and specificity. The imaging capacity, biodistribution, pharmacokinetics, and radiation dosimetry were investigated. Flow cytometry, autoradiography, and immunohistochemical staining were used to confirm the expression of TIGIT. The safety and potential of 68Ga-GP12 for PET/CT imaging of TIGIT expression were evaluated in NSCLC patients. RESULTS: 68Ga-labeled D-peptides were conveniently produced with high radiochemical yields, radiochemical purities and molar activities. In vitro binding assays demonstrated 68Ga-GP12 has high affinity and specificity for TIGIT with a KD of 37.28 nM. In vivo and ex vivo studies demonstrated the capacity of 68Ga-GP12 for PET imaging of TIGIT expression with high tumor uptake of 4.22 ± 0.68 %ID/g and the tumor-to-muscle ratio of 12.94 ± 2.64 at 60 min post-injection. In NSCLC patients, primary and metastatic lesions found in 68Ga-GP12 PET images were comparable to that in 18F-FDG PET images. Moreover, tracer uptake in primary and metastatic lesions and intra-tumoral distribution in the large tumor were inhomogenous, indicating the heterogeneity of TIGIT expression. CONCLUSION: 68Ga-GP12 is a promising radiotracer for PET imaging of TIGIT expression in cancers, indicating its potential as a potential companion diagnostic for anti-TIGIT therapies.

Reversible Data Hiding By Using CNN Prediction and Adaptive Embedding.

In the field of reversible data hiding (RDH), how to predict an image and embed a message into the image with smaller distortion are two important aspects. In this paper, we propose a novel and efficient RDH method by innovating an intelligent predictor and an adaptive embedding way. In the prediction stage, we first constructed a convolutional neural network (CNN) based predictor by reasonably dividing an image into four parts. In such a way, each part can be predicted by using the other three parts as the context for the improvement of the prediction performance. Compared with existing predictors, the proposed CNN predictor can use more neighboring pixels for the prediction by exploiting its multi-receptive fields and global optimization capacities. In the embedding stage, we also developed a prediction-error-ordering (PEO) based adaptive embedding strategy, which can better adapt image content and thus efficiently reduce the embedding distortion by elaborately and luminously applying background complexity to select and pair those smaller prediction errors for data hiding. With the proposed CNN prediction and embedding ways, the RDH method presented in this paper provides satisfactory results in improving the visual quality of data hidden images, e.g., the average PSNR value for the Kodak benchmark dataset can reach as high as 63.59 dB with an embedding capacity of 10,000 bits. Extensive experimental results have shown that the RDH method proposed in this paper is superior to those existing state-of-the-art works.

Cover-Lossless Robust Image Watermarking Against Geometric Deformations.

Cover-lossless robust watermarking is a new research issue in the information hiding community, which can restore the cover image completely in case of no attacks. Most countermeasures proposed in the literature usually focus on additive noise-like manipulations such as JPEG compression, low-pass filtering and Gaussian additive noise, but few are resistant to challenging geometric deformations such as rotation and scaling. The main reason is that in the existing cover-lossless robust watermarking algorithms, those exploited robust features are related to the pixel position. In this article, we present a new cover-lossless robust image watermarking method by efficiently embedding a watermark into low-order Zernike moments and reversibly hiding the distortion due to the robust watermark as the compensation information for restoration of the cover image. The amplitude of the exploited low-order Zernike moments are: 1) mathematically invariant to scaling the size of an image and rotation with any angle; and 2) robust to interpolation errors during geometric transformations, and those common image processing operations. To reduce the compensation information, the robust watermarking process is elaborately and luminously designed by using the quantized error, the watermarked error and the rounded error to represent the difference between the original and the robust watermarked image. As a result, a cover-lossless robust watermarking system against geometric deformations is achieved with good performance. Experimental results show that the proposed robust watermarking method can effectively reduce the compensation information, and the new cover-lossless robust watermarking system provides strong robustness to those content-preserving manipulations including scaling, rotation, JPEG compression and other noise-like manipulations. In case of no attacks, the cover image can be recovered without any loss.

Reversible Data Hiding Algorithm in Fully Homomorphic Encrypted Domain.

This paper proposes a reversible data hiding scheme by exploiting the DGHV fully homomorphic encryption, and analyzes the feasibility of the scheme for data hiding from the perspective of information entropy. In the proposed algorithm, additional data can be embedded directly into a DGHV fully homomorphic encrypted image without any preprocessing. On the sending side, by using two encrypted pixels as a group, a data hider can get the difference of two pixels in a group. Additional data can be embedded into the encrypted image by shifting the histogram of the differences with the fully homomorphic property. On the receiver side, a legal user can extract the additional data by getting the difference histogram, and the original image can be restored by using modular arithmetic. Besides, the additional data can be extracted after decryption while the original image can be restored. Compared with the previous two typical algorithms, the proposed scheme can effectively avoid preprocessing operations before encryption and can successfully embed and extract additional data in the encrypted domain. The extensive testing results on the standard images have certified the effectiveness of the proposed scheme.

MicroRNA­135b regulates the stability of PTEN and promotes glycolysis by targeting USP13 in human colorectal cancers.

Dysregulation of microRNAs has been reported to be involved in the progression of human colorectal cancers (CRCs). Loss of the adenomatous polyposis coli (APC) gene is a common initiating event in CRCs. PTEN inactivation by mutation or allelic loss also occurs in CRCs. miR­135b was reported to be upregulated in CRCs and its overexpression was due to APC/ß­catenin and PTEN/PI3K pathway deregulation. APC was proven to be a target of miR­135b and forms a feedback loop with miR­135b. In the present study, we found that ubiquitin­specific peptidase 13 (USP13) was a target of miR­135b. miR­135b downregulated the expression of USP13, and reduced the stability of PTEN. miR­135b promoted cell proliferation and glycolysis that could be reversed by the overexpression of USP13 or PTEN. Moreover, knockdown of USP13 upregulated the levels of endogenous miR­135b, but not those in CRC cells with PTEN mutation. The results showed positive feedback loops between miR­135b and PTEN inactivation in CRCs.