Publications by authors named "Lingyi Sun"

Prior studies have reported connections between cathepsins (CTS) and gynecological cancers; however, the exact causal links are yet to be fully understood. Leveraging publicly accessible genome-wide association study summary datasets, we performed a two-sample bidirectional Mendelian randomization (MR) and multivariate MR (MVMR) analysis, with the inverse variance weighted (IVW) method as the primary approach. MR analysis demonstrated inverse associations between CTSB and cervical cancer (IVW: odds ratio [OR] = 0.

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The exploration of pharmaceutically active agents and positron emission tomography (PET) tracers targeting CXCR4 has been a focal point in cancer research given its pivotal role in the development and progression of various cancers. While significant strides have been made in PET imaging with radiometal-labeled tracers, the landscape of F-labeled small molecule tracers remains relatively limited. Herein, we introduce a novel and promising derivative, [F]SFB-AMD3465, as a targeted PET tracer for CXCR4.

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Article Synopsis
  • PET imaging is now a key diagnostic tool in precise medicine, with various pre-targeting methods developed to improve traditional immuno-PET's limitations.
  • The new Dual-Receptor Pre-Targeting (DRPT) system enhances tumor radioligand uptake and retention by using a tumor-receptor-specific peptide, outperforming previous methods.
  • DRPT is compatible with short-lived isotopes, could reduce the necessary amount of pre-administered antibodies, and offers a potential cost-saving approach in antibody-based molecular imaging.
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Purpose: Pancreatic ductal adenocarcinoma (PDAC) is the most lethal gastrointestinal cancer, and its poor prognosis is highly associated with the lack of an efficient early detection technology. Here, we report that RGD-NGR heterodimer labeled with PET isotope could be applied in PDAC early detection.

Procedures: The RGD-NGR tracer was first compared with its corresponding monomeric counterparts via PET imaging studies using mice bearing a subcutaneous BxPC3 tumor.

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Article Synopsis
  • Advances in chelator design, particularly using pendant armed 1,4,7-triazacyclononane derivatives, drive the creation of effective copper and gallium-based biomedical agents and radiopharmaceuticals.
  • The synthesized chelators, including NODA-Im, NODA-MeIm, and NODA-Thia, showed faster complexation rates with Cu (II) compared to the commonly studied NOTA ligand, while the NODP-Thia demonstrated superior binding to Ga (III).
  • The study's findings suggest that these novel chelators may significantly improve efficiency in binding and radiolabeling, positioning them as promising candidates for future biomedical applications.
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Imaging of CD8 receptors on T-cells by positron emission tomography (PET) has been considered a promising strategy for monitoring the treatment response to immunotherapy. In this study, a trial of imaging CD8 with our newly developed sequential multiple-agent receptor targeting (SMART) technology was conducted. Mice bearing a subcutaneous colorectal CT26 tumor received three times different immunotherapy treatments (PD1 or CTLA4 or combined).

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Radiofrequency ablation (RFA) has been clinically used as a minimally invasive procedure for the treatment of many solid tumors. However, the current imaging techniques have some shortages in RFA guidance, especially for the assessment of the margin of ablation. Herein, we developed a novel optical imaging platform to guide RFA utilizing fluorescence resonance energy transfer from a thermally sensitive fluorescent protein conjugated to a near-infrared fluorescent dye.

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A novel photo-click-based platform has been developed for rapid screening and affinity optimization of heterobivalent agents. This method allows for the efficient selection of high-affinity dual receptor-targeting agents streamlining tedious organic synthesis and biological evaluation procedures required by traditional approaches. The high-avidity heterobivalent agents targeting both integrin αβ and urokinase-type plasminogen activator receptors have been developed using this photo-click-facilitated screening platform.

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Integrin αβ and aminopeptidase N (APN, also known as CD13) are two important targets involved in the regulation of angiogenesis, tumor proliferation, invasion, and metastasis. In this study, we developed a heterodimeric tracer consisting of arginine-glycine-aspartic (RGD) and asparagine-glycine-arginine (NGR) peptides targeting αβ and CD13, respectively, for PET imaging of breast cancer. The NGR peptide was first modified with N-NOB and then conjugated to BCN-PEG-c(RGDyK) via copper-free click chemistry.

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Malignant melanoma is an aggressive cancer with poor prognosis. Very late antigen-4 (VLA-4) is overexpressed in melanoma and many other tumors, making it an attractive target for developing molecular diagnostic and therapeutic agents. We compared AlF- and Ga-labeled LLP2A peptides for PET imaging of VLA-4 expression in melanoma.

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Ubiquitin has been recently identified as a chemokine receptor 4 (CXCR4) natural ligand, offering great potential for positron emission computed tomography (PET) imaging of CXCR4 expression. This study reports the preparation and evaluation of (Cu)-radiolabeled ubiquitin for CXCR4 imaging. The ubiquitin was first fused with a C-terminal GGCGG sequence, and the resulting recombinant ubiquitin derivative UbCG4 was then functionalized with the -cyclooctene (TCO) moiety via thiol-maleimide click reaction, followed by Cu-radiolabeling through the TCO/Tz (tetrazine)-based Diels-Alder click reaction.

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Due to the increasing use of generator-produced radiometal Gallium-68 (Ga) in positron-emission tomography/computed tomography (PET/CT), reliable bifunctional chelators that can efficiently incorporate Ga into biomolecules are highly desirable. In this study, we synthesized two new bifunctional chelators bearing one or two phosphonic acid functional groups, named p-SCN-PhPr-NE2A1P and p-SCN-PhPr-NE2P1A, with the aim of enabling facile production of Ga-based radiopharmaceuticals. Both chelators were successfully conjugated to LLP2A-PEG, a very late antigen-4 (VLA-4) targeting peptidomimetic ligand, to evaluate their application in Ga-based PET imaging.

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Unlabelled: Multifunctional nanoplatforms offering simultaneous imaging and therapeutic functions have been recognized as a highly promising strategy for personalized nanomedicine. In this work, we synthesized a farnesylthiosalicylate (FTS, a nontoxic Ras antagonist) based triblock copolymer POEG-b-PVBA-b-PFTS (POVF) composed of a poly(oligo(ethylene glycol) methacrylate) (POEG) hydrophilic block, a poly(FTS) hydrophobic block, and a poly(4-vinylbenzyl azide) (PVBA) middle block. The POVF polymer itself was active in inhibiting the tumor growth in vitro and in vivo.

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Molecular imaging is critical to personalized and precision medicine. Although singly targeted imaging probes are making an impact both clinically and preclinically, molecular imaging strategies using bispecific probes have enabled improved visualization of cancer in recent years through synergistic targeting of two ligands. In this Focus on Molecular Imaging review, we outline how peptide-, antibody-, and nanoparticle-based platforms have affected this emerging strategy, providing examples and pointing out areas in which the greatest clinical impact may be realized.

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Background & Aims: Maintenance of acid-base homeostasis is required for normal physiology, metabolism, and development. It is not clear how cell death is activated in response to changes in pH. We performed a screen to identify agents that induce cell death in a pH-dependent manner (we call this alkaliptosis) in pancreatic ductal adenocarcinoma cancer (PDAC) cells and tested their effects in mice.

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Radiation therapy (RT) can induce upregulation of programmed death ligand 1 (PD-L1) on tumor cells or myeloid cells, which may affect response to PD-1-based immunotherapy. PD-L1 upregulation during RT is a dynamic process that has been difficult to monitor during treatment. The aim of this study was to evaluate the RT-induced PD-L1 upregulation in the tumor and its microenvironment using immunoPET/CT imaging of two syngeneic murine tumor models (HPV+ head and neck squamous cell carcinoma (HNSCC) or B16F10 melanoma).

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The purpose of this article is to evaluate feasibility and safety of the cancer targeting (radio)-chemoembolization drug-eluting bead (TRCE-DEB) concept drug SW43-DOX-L-NETA(Y) DEB for the intra-arterial treatment of VX2 rabbit liver tumors. The treatment compound comprises of the sigma-2 receptor ligand SW43 for cancer targeting, doxorubicin (DOX), and yttrium (Y) as nonradioactive surrogate for therapeutic (yttrium-90, lutetium-177) and imaging (yttrium-86) radioisotopes via the chelator L-NETA. Ten New Zealand white rabbits with VX2 tumor allografts were used.

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BACKGROUND The aim of this study was to develop a novel Poloxamer-based drug delivery system featuring a tumor-targeting folate moiety, which was expected to provide better targeting properties and therapeutic effects compared with the traditional cubosomes (Cubs). MATERIAL AND METHODS Both folate-modified Cubs containing etoposide (ETP-Cubs-FA) and normal cubic nanoparticles loaded with etoposide (ETP-Cubs) were prepared through the fragmentation of bulk gels under the homogenization condition of 1500 bar, and a mean particle size of around 180 nm was obtained with a narrow size distribution. The cubosomes were further characterized by differential scanning calorimetry (DSC) and Polarized light microscopy (PLM).

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Purpose: Sunitinib drug eluting beads (DEB) are a novel anti-angiogenic bead preparation for use in transarterial chemoembolization. However, systematic studies of sunitinib DEB's effect on cancer cells have not been reported. Herein, we assess their direct biologic efficacy against carcinoma cell lines and correlate cell viability with drug release in vitro.

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Bifunctional chelators play an important role in developing metallic radionuclide-based radiopharmaceuticals. In this study, a new bifunctional ligand, p-SCN-PhPr-NE3TA, was synthesized and conjugated to a very late antigen-4 targeting peptidomimetic, LLP2A, for evaluating its application in (64)Cu-based positron emission tomography (PET) imaging. The new ligand exhibited strong selective coordination of Cu(II), leading to a robust Cu complex, even in the presence of 10-fold Fe(III).

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Treatment of unresectable primary cancer and their distant metastases, with the liver representing one of the most frequent location, is still plagued by insufficient treatment success and poor survival rates. The Sigma-2 receptor is preferentially expressed on many tumor cells making it an appealing target for therapy. Thus, we developed a potential targeted drug conjugate consisting of the Sigma-2 receptor ligand SW43 and Doxorubicin (SW43-DOX) for systemic cancer therapy and for locoregional treatment of primary and secondary liver malignancies when loaded onto drug-eluting bead (DEB) which was compared in vitro to the treatment with Doxorubicin alone.

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Preparation of small molecule based dual-modality probes remains a challenging task due to the complicated synthetic procedure. In this study, a novel concise and generic strategy for preparing dual-modality optical/PET imaging probes via photo-click chemistry was developed, in which the diazole photo-click linker functioned not only as a bridge between the targeting-ligand and the PET imaging moiety, but also as the fluorophore for optical imaging. A dual-modality AE105 peptidic probe was successfully generated via this strategy and subsequently applied in the fluorescent staining of U87MG cells and the (68)Ga based PET imaging of mice bearing U87MG xenograft.

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Multivalent and multimodal imaging probes are rapidly emerging as powerful chemical tools for visualizing various biochemical processes. Herein, we described a bifunctional chelator (BFC)-based scaffold that can be used to construct such promising probes concisely. Compared to other reported similar scaffolds, this new BFC scaffold demonstrated two major advantages: (1) significantly simplified synthesis due to the use of this new BFC that can serve as chelator and linker simultaneously; (2) highly efficient synthesis rendered by using either click chemistry and/or total solid-phase synthesis.

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A novel ligand (FBTTBE) for Cu(i)-catalyzed azide-alkyne cycloaddition (CuAAC) has been developed, which demonstrates not only superior catalytic efficiency but also the ease of removing toxic copper species. FBTTBE has also been successfully applied in the synthesis of radiometal-labeled peptide and antibody without observable transchelation with the non-radioactive Cu(i) catalyst.

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The AlkB family of nucleic acid demethylases are of intense biological and medical interest because of their roles in nucleic acid repair and epigenetic modification. However their functional and molecular mechanisms are unclear, hence, there is strong interest in developing selective inhibitors for them. Here we report the identification of key residues within the nucleotide-binding sites of the AlkB subfamilies that likely determine their substrate specificity.

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