Target Identification and Mechanistic Characterization of Indole Terpenoid Mimics: Proper Spindle Microtubule Assembly Is Essential for Cdh1-Mediated Proteolysis of CENP-A.

Centromere protein A (CENP-A), a centromere-specific histone H3 variant, is crucial for kinetochore positioning and chromosome segregation. However, its regulatory mechanism in human cells remains incompletely understood. A structure-activity relationship (SAR) study of the cell-cycle-arresting indole terpenoid mimic JP18 leads to the discovery of two more potent analogs, (+)-6-Br-JP18 and (+)-6-Cl-JP18. Tubulin is identified as a potential cellular target of these halogenated analogs by using the drug affinity responsive target stability (DARTS) based method. X-ray crystallography analysis reveals that both molecules bind to the colchicine-binding site of ß-tubulin. Treatment of human cells with microtubule-targeting agents (MTAs), including these two compounds, results in CENP-A accumulation by destabilizing Cdh1, a co-activator of the anaphase-promoting complex/cyclosome (APC/C) E3 ubiquitin ligase. This study establishes a link between microtubule dynamics and CENP-A accumulation using small-molecule tools and highlights the role of Cdh1 in CENP-A proteolysis.

Application of Carbon Nanoparticles in Transoral Endoscopic Thyroidectomy Vestibular Approach for Unilateral Papillary Thyroid Cancer.

BACKGROUND: Transoral endoscopic thyroidectomy vestibular approach (TOETVA) is newly applied technology. Carbon nanoparticles (CNs) are novel lymph node tracers that have been widely used in China to help remove central lymph nodes (CLNs) and protect the parathyroid glands (PGs) in open thyroid cancer surgery. This study is to evaluate the effectiveness and safety of CNs in TOETVA. MATERIALS AND METHODS: A total of 158 patients who underwent TOETVA with unilateral papillary thyroid carcinoma were enrolled in this study from March 2019 to February 2022. The participants were divided into a CNs group (n=88) and a control group (n=70), based on whether they received a intraoperative injection of CNs or not. Meanwhile, the CNs group were additionally divided into 2 subgroups, leakage subgroup (n=26) and standard subgroup (n=62). The 2 groups and subgroups were compared in terms of patient characteristics, perioperative clinical results, and postoperative outcomes. RESULTS: All common metrics had no significant differences were found between the CNs group and the control group ( P >0.05). The standard subgroup of CNs group had advantage over the control group on PGs identification (59/62 vs. 59/70 for superior PG, 56/62 vs. 52/70 for inferior PG, P <0.05). Moreover, the standard subgroup harvested more CLNs than the control group (8.97±2.96 vs. 7.47±2.93, P <0.05). More operation time was spent on the leakage subgroup of CNs group than the control group (160.00±17.61 vs. 140.00±13.32, P <0.05). Meanwhile, the leakage subgroup had disadvantage on intraoperative hemorrhage (26.15±10.80 vs. 21.21±7.09, P <0.05) and hospital durations (4.96±0.72 vs. 4.57±0.69, P <0.05). Furthermore, the leakage group identified fewer inferior PG than the control group (7/26 vs. 52/70, P <0.05). Contrary to the standard subgroup, the CLNs of the leakage subgroup was also unsatisfactory compared with the control group (4.96±1.84 vs. 7.47±2.93, P <0.05). CONCLUSIONS: The application of CNs suspension tracing technology has a definite effect in TOETVA. It can improve the thoroughness of lymph node dissection in the central region and enhance recognition of the PG. However, refined extracapsular anatomy is indispensable to prevent CN leakage. Leaked CNs will also be counterproductive to the operation.

Visible-Light-Mediated Three-Component Strategy for the Synthesis of Isoxazolines and Isoxazoles.

Isoxazolines and isoxazoles commonly serve as core structures of many therapeutic agents and natural products. However, the metal-free and catalysis-free strategy for the synthesis of these privileged motifs at room temperature remains a challenging task. Herein, we report a three-component strategy to afford diverse isoxazolines and isoxazoles via [3 + 2] cycloadditions of in situ-formed nitronates and olefins/alkynes under visible-light irradiation.

Acetone Serving as a Solvent and Interaction Partner Promotes the Direct Olefination of N-Tosylhydrazones under Visible Light.

The photochemistry of noncovalent interactions to promote organic transformations is an emerging approach to providing fresh opportunities in synthetic chemistry. Generally, the external substance is necessary to add as an interaction partner, thereby sacrificing the atom economy of the reaction. Herein, we describe a catalyst-free and noncovalent interaction-mediated strategy to access the olefination of N-tosylhydrazones using acetone as a solvent and an interaction partner. This protocol also features broad substrate scope, excellent functional group compatibility, and mild reaction conditions without transition metals. Moreover, the gram-scale synthesis of olefins and the generation of pharmaceutical intermediates highlighted its practical applicability. Lastly, mechanistic studies indicate that the reaction was initiated via noncovalent interactions between acetone and N-tosylhydrazone anion, which is also supported by density functional theory calculations.

Oncolytic Peptide-Nanoplatform Drives Oncoimmune Response and Reverses Adenosine-Induced Immunosuppressive Tumor Microenvironment.

The application of oncolytic peptides has become a powerful approach to induce complete and long-lasting remission in multiple types of carcinomas, as affirmed by the appearance of tumor-associated antigens and adenosine triphosphate (ATP) in large quantities, which jumpstarts the cancer-immunity cycle. However, the ATP breakdown product adenosine is a significant contributor to forming the immunosuppressive tumor microenvironment, which substantially weakens peptide-driven oncolytic immunotherapy. In this study, a lipid-coated micelle (CA@TLM) loaded with a stapled oncolytic peptide (PalAno) and an adenosine 2A receptor (A2AR) inhibitor (CPI-444) is devised to enact tumor-targeted oncolytic immunotherapy and to overcome adenosine-mediated immune suppression simultaneously. The CA@TLM micelle accumulates in tumors with high efficiency, and the acidic tumor microenvironment prompts the rapid release of PalAno and CPI-444. Subsequently, PalAno induces swift membrane lysis of tumor cells and the release of antigenic materials. Meanwhile, CPI-444 blocks the activation of the immunosuppressive adenosine-A2AR signaling pathway. This combined approach exhibits pronounced synergy at stalling tumor growth and metastasis in animal models for triple-negative breast cancer and melanoma, providing a novel strategy for enhanced oncolytic immunotherapy.

Expanding the ubiquitin code in pancreatic cancer.

The ubiquitin-proteasome system (UPS) is a fundamental regulatory mechanism in cells, vital for maintaining cellular homeostasis, compiling signaling transduction, and determining cell fates. These biological processes require the coordinated signal cascades of UPS members, including ubiquitin ligases, ubiquitin-conjugating enzymes, deubiquitinases, and proteasomes, to ubiquitination and de-ubiquitination on substrates. Recent studies indicate that ubiquitination code rewriting is particularly prominent in pancreatic cancer. High frequency mutation or aberrant hyperexpression of UPS members dysregulates ferroptosis, tumor microenvironment, and metabolic rewiring processes and contribute to tumor growth, metastasis, immune evasion, and acquired drug resistance. We conduct an in-depth overview of ubiquitination process in pancreatic cancer, highlighting the role of ubiquitin code in tumor-promoting and tumor-suppressor pathways. Furthermore, we review current UPS modulators and analyze the potential of UPS modulators as cancer therapy.