RATIONALE AND OBJECTIVE:Anaplastic thyroid carcinoma (ATC) may arise from the progression of differentiated thyroid cancers, but the mechanisms are not well understood. Establishing appropriate animal models and conducting ultrasound imaging monitoring can facilitate the study of this dedifferentiation process. MATERIALS AND METHODS:We constructed mouse models of papillary thyroid carcinoma (PTC) and ATC by editing the Braf mutation and Trp53 deletion, and monitored the process using small-animal ultrasound. The you only look once computer model was employed to process ultrasound images, analyze the characteristics of ultrasound images from different tumors and build a lesion identification and diagnostic model. The molecular expression characteristics of PTC with potential for dedifferentiation were analyzed through RNA sequencing. RESULTS:Mice ATCs exhibited a characteristic five-phase growth curve, accompanied by earlier lung metastasis. The mice thyroid tumor lesion recognition model was capable of identifying different types of tumor lesions and simulating their progression process with an accuracy of 0.765. Some PTCs showed lower Thyroid Differentiation Scores and were associated with high expression of genes such as Ptprn2, Tnfsf18 and Cdkn2a. CONCLUSION:This study validated the hypothesis that Trp53 deletion and Braf mutation promote the progression of PTC to ATC through ultrasound monitoring and computer modeling. Certain PTCs with the potential for dedifferentiation exhibit a specific molecular expression profile, which may represent potential therapeutic targets.

Two series of [1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine derivatives have been synthesized and evaluated for their antitumor activities. These compounds exhibit potent antiproliferative activities against A549 and H460 cells and c-Met kinase inhibitory activities. Five compounds are highly effective against A549 and H460 cells with IC50 values in 2.97-16.50 μM (the mean ± SD value of three independent determinations). Molecular docking is further performed to study the inhibitor-c-Met kinase interactions, and the results show that compound 3a is potently bound to the c-Met kinase with three hydrogen bonds, one π---π, and one CH---π interactions. Based on the preliminary results, it is deduced that compound 3a with potent c-Met kinase inhibitory activity may be a potential anticancer agent.

Systemic chemotherapy remains the most frequent treatment for triple-negative breast cancer (TNBC) because the tumors do not express any of the three surface receptors targeted by selected treatments. A more selective alternative may be delivering drugs such as the well established anti-tumor drug as well as mitochondrial toxin doxorubicin to mitochondria in tumor cells by carriers containing TNBC surface proteins and delocalized lipophilic cations such as berberine derivatives that can target TNBC tumors and mitochondria, respectively. Once they enter tumor cells, the drug-loaded carriers will target to the mitochondria and inactivate them in the presence of cations. Here we synthesized amphiphilic 9-O-cetyl-berberine, which retained the anti-tumor activity of berberine, through a method involving microwave irradiation, then allowed the molecules to co-assemble spontaneously with doxorubicin into micelles. The micelles were coated with membranes derived from erythrocytes and the TNBC cell line MDA-MB-231 to shield their cytotoxic and hemolytic positive charge. The resulting nanovesicles showed good stability in the short term and good safety, and synergistically inhibited proliferation and migration of TNBC cells by reducing mitochondrial membrane potential and promoting the generation of reactive oxygen species and activating apoptotic signaling. These results establish the potential of this system to co-deliver doxorubicin and delocalized lipophilic cations to treat TNBC.

The thermal processing methods significantly alter the flavor profile of meat. This study investigated the effects of four techniques: steaming (ST), boiling (BO), blanching (TB), and microwave heating (WB) on the Volatile flavor compounds (VOCs) of Maiwa yak meat using E-nose, E-tongue, GC-MS, and GC-IMS analysis. Key findings include: E-nose/E-tongue data indicated similar aroma and taste profiles across methods, but the overall sensory quality was optimal in TB and WB samples. 48 VOCs were identified by both GC-MS and GC-IMS. Thermal processing significantly elevated aldehydes and ketones concentrations, enhancing meat flavor complexity. OPLS-DA modeling of GC-MS/GC-IMS data screened 5 and 8 significantly differentiated aroma markers (VIP > 1 and P < 0.05), respectively. Molecular docking revealed that Nonanal formed the most stable binding with receptor OR1D2 (−6.78 kcal/mol) via hydrogen bonds and hydrophobic interactions, and 1-Octen-3-ol exhibited strong binding to myosin (−5.17 kcal/mol) and OR1A1 (−6.64 kcal/mol) through analogous mechanisms.

Small molecule blockade of the programmed death receptor 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway represents a promising approach for tumor immunotherapy. Based on the previously developed 3D-quantitative structure-activity relationship pharmacophore model for PD-L1 inhibitors, virtual screening followed by homogeneous time-resolved fluorescence (HTRF) activity testing identified the compound {1-[(biphenyl-4-yl)methyl]-7-methoxy-1,2,3,4-tetrahydroisoquinolin-6-yl}acetic acid methyl ester (Compound Y6) as a hit. Analysis of computational docking results of compound Y6 with PD-L1 suggested targeting the methyl acetate substituent at position 6 for optimization. Guided by this, 20 new derivatives were designed and synthesized. The synthesized compounds were subjected to HTRF test and 6 compounds with significant protein blocking effects were screened for subsequent surface plasmon resonance (SPR) test. Subsequent SPR analysis confirmed strong binding of these 6 compounds to hPD-L1 protein with K D values ranging from 0.24 to 21.31 μM. Several derivatives displayed improved or comparable PD-L1 binding affinity relative to the lead compound Y6 (K D = 11.3 μM). A co-incubation system (PD-1+ Jurkat T/PD-L1+ HepG2) was established to evaluate functional immune restoration. This evaluation revealed that compound Y7f effectively promoted HepG2 cells death by restoring T cell immune function. MD simulations identify (1R,16R)-Y7f as the most potent PD-L1 dimerization inducer within the compound Y7f stereoisomer series. The results indicated that the biphenyl-tetrahydroisoquinoline scaffold is a promising structural framework for developing novel PD-1/PD-L1 inhibitors and deserves further investigation.

In this study, we designed and synthesized a series of compounds derived from the histone deacetylase inhibitor (HDACi) Chidamide and the BET bromodomain inhibitor (+)-JQ-1. All target compounds were structurally characterized by 1H NMR, 13C NMR, and high-resolution mass spectrometry (HRMS). Antiproliferative activity was assessed by an MTT assay in MDA-MB-231 (breast cancer), HeLa (cervical cancer), and HCT116 (colon cancer) cells, with chidamide and (+)-JQ-1 as reference compounds; cytotoxicity in 293 T cells was further evaluated to estimate selectivity. Results indicated that most derivatives exhibited superior activity to Chidamide, with compound 6e demonstrating the strongest inhibitory effect against MDA-MB-231 cells. The IC50 values of 6e were 0.10 ± 0.02 μM (MDA-MB-231), 0.90 ± 0.17 μM (HeLa), 19.60 ± 0.90 μM (HCT116), and 70.13 ± 5.19 μM (293 T). Further assays showed that 6e inhibited colony formation, migration, adhesion, and invasion of MDA-MB-231 cells in a concentration-dependent manner. Annexin V-FITC/PI flow cytometry indicated apoptosis induction. In the chicken embryo chorioallantoic membrane (CAM) model, 6e inhibited tumor growth and angiogenesis more effectively than chidamide. In summary, 6e demonstrates promising optimization potential as a lead compound for breast cancer therapy.

Using cyclopropyl radicals to install cyclopropanes has been a fast-growing research field in recent years. Meanwhile, direct radical carbonyl alkylative amination has emerged as an ideal protocol for constructing α-branched tertiary amines. Based on the strategy of direct addition of cyclopropyl radicals to in situ generated iminium ions, we disclose a method for preparing diverse α-cyclopropyl tertiary alkylamines by photogenerated-radical cyclopropylation mediated by NaI/PPh3 using abundant feedstocks (aldehydes and amines) and easily procured cyclopropyl active esters. Importantly, NaI/PPh3 works as both the photoinitiator and sacrificial reductant in this reaction and hence gives an economical variant of carbonyl alkylative amination under mild reaction conditions. In addition, the electrochemical variant of this photogenerated-radical cyclopropylation was also investigated with the preliminary results.

Studying the selectivity mechanism of inhibitors towards highly similar isoforms is an important task in the development of new drugs, which are designed to avoid the undesired side effects in vivo. CDC-like kinase isoforms (CLKs) are serine/threonine protein kinases that are involved in the phosphorylation of mRNA spliceosomes leading to the regulation of gene expression. The CLK isoforms are expressed in most human tissues and cells, but the expression levels of each isoform vary in different cells. Typically, CLK3 is expressed in male testes and sperm, by contrast, as a potential cancer treatment target, the expression level of CLK1 in testicular tissue is significantly lower than other isoforms. These differences in the tissue distribution of CLK1 and CLK3 suggest that the development of selective CLK1 inhibitors to avoid potential side effects. Here, our study is designed to reveal the selectivity mechanism of CLK1 inhibition from a computational perspective. In this study, the binding modes of known selective inhibitors towards CLK1/3 are discussed by computational methods such as protein comparison, molecular docking, binding free energy calculation, molecular dynamics simulations, alanine mutagenesis simulations, and quantum mechanical calculation. The simulations reveal selective key roles involved in CLK1/3 binding, including protein-ligand interactions, mutations, and conformational differences in key amino acid residues. This study will contribute to analyze the selectivity mechanism of CLKs inhibitors and bring insight into the development of novel selective inhibitor drugs.

This study aimed to demonstrate the utility of a network toxicology strategy in elucidating osteotoxicity and the molecular mechanisms of endocrine-disrupting chemicals (EDCs) using triclosan exposure in postmenopausal osteoporosis (PMOP) as a case study. The potential targets of triclosan were identified using the Comparative Toxicogenomics Database, SwissTargetPrediction, and TargetNet. PMOP-related targets were obtained from GeneCards, DisGeNET, and DrugBank. A total of 478 overlapping genes between disease targets and triclosan effectors were identified. Subsequent analysis using STRING and Cytoscape, applying the Matthews correlation coefficient algorithm, identified five core genes: STAT3, TP53, EGFR, MYC, and JUN. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses performed using R revealed that triclosan-induced PMOP is primarily associated with disrupted endocrine signaling and activation of the Phosphoinositide 3-kinase (PI3K)-Protein kinase B (Akt) signaling pathway. Molecular docking using CB-Dock2 confirmed strong binding affinities between triclosan and the core targets. Collectively, these results indicate that triclosan adversely affects bone health by disrupting endocrine regulation and energy metabolism through the PI3K-Akt pathway. This study establishes a theoretical framework for understanding how long-term triclosan exposure induces or exacerbates PMOP by investigating the underlying molecular mechanisms. These findings present a novel paradigm for evaluating the health risks posed by environmental pollutants.

PAK4, the most studied member of group II PAK, plays crucial roles in multiple cancer cell signaling pathways. To date , only PAK4 inhibitor KPT9274 is under clinical development with no detailed binding mechanism. The PROTAC technology offers a new chance to study PAK4 by selective protein degradation. Here, we report the development of CPS-021, a selective PAK4 degrader derived from our previously reported compound CPL-042 conjugated to pomalidomide. CPS-021 induced selective degradation of PAK4 with DC50 = 50 nM and exhibited significant antimigratory and invasive activity. The A549-luc lung metastasis in vivo model demonstrated that CPS-021 effectively inhibited the invasion and metastasis of tumor cells in nude mice. Our findings provide evidence that the selective PAK4 degrader exhibits significant pharmacological effects in suppressing cancer cell migration and invasion. These results support the further development of CPS-021 as a valuable tool compound for conducting in-depth biological investigations of group II PAKs.

Lenvatinib resistance, driven by metabolic adaptation and angiogenic escape, poses a major challenge in hepatocellular carcinoma (HCC) therapy. This study explores bezafibrate, a clinically approved Peroxisome Proliferator-Activated Receptor Alpha or Gamma (PPARα/γ) dual agonist, to enhance lenvatinib sensitivity by inducing PTEN-Induced Putative Kinase 1(PINK1)/ Parkin-mediated mitophagy. Using SNU-739/HepG2 cells, we investigated bezafibrate's anti-tumor efficacy alone and in combination with lenvatinib. The results demonstrated that bezafibrate alone exhibits anti-tumor efficacy in HCC and enhances the anti-HCC efficacy of lenvatinib. It was observed that bezafibrate activated PPARα, increasing fatty acid oxidation (FAO) via Carnitine Palmitoyltransferase IA (CPT1A)/ Acyl-CoA Oxidase 1(ACOX1) upregulation, leading to elevated ROS and reduced mitochondrial membrane potential (ΔΨm). It also activated PPARγ, which bound to PINK1 with high affinity (ΔG = -64.6 kcal/mol). Dual PPARα/γ activation by bezafibrate enhanced Parkin recruitment and promoted mitophagic cell death, characterized by reduced p62 and Translocase of Outer Mitochondrial Membrane 20 (TOM20), increased LC3-II, decreased ATP, and elevated Annexin V-positive cells. This approach demonstrated efficacy, inducing PINK1/Parklin-mediated mitophagy and reducing VEGF-A/C and EGFR in vitro, and decreasing tumor volume and weight in a syngeneic H22 mouse model compared to lenvatinib alone, without significant toxicity. In conclusion, bezafibrate, through PPARα/γ-mediated PINK1/Parkin activation and angiogenic suppression, complements lenvatinib's therapeutic effects in HCC, providing a rationale for clinical evaluation to address treatment resistance.

Pexidartinib (PEX, TURALIO®), a tyrosine kinase inhibitor, is approved for treating tenosynovial giant cell tumor in adults. However, its potential to cause fatal liver injury has prompted the U.S. FDA to issue a black box warning, and the mechanisms underlying its hepatotoxicity remain largely unknown. As biotransformation may contribute to PEX-induced hepatotoxicity, understanding its metabolism is essential. Our previous research indicated that PEX forms reactive metabolites in human and mouse liver microsomes and in human hepatocytes. We investigated PEX metabolism and liver distribution in mice with a focus on metabolite characterization. Our data shows that PEX is mainly excreted into mouse feces as an unchanged drug, in line with findings in humans. Thirty phase I metabolites reported in our previous in vitro studies were detected in mouse feces, urine, plasma, and/or liver; these include the products of unusual carbon-carbon bond cleavages. Twenty-eight phase II PEX metabolites were tentatively identified, including 12 glucuronides, 6 sulfates, 1 glucose conjugate, 2 glutathione, 1 cysteinyl-glycine, and 6 N-acetylcysteine adducts; 24 of these have not previously been reported. The detection of glutathione-PEX adducts and their degradation products indicates that reactive PEX metabolites are generated in mice, consistent with our previous findings in liver microsomes. Since glutathione-PEX adducts are also generated in human primary hepatocytes, the discovery of these new metabolites may help others to clarify the previously unknown metabolic fates of some PEX in human studies and provide starting points for investigations into PEX toxicity by further assessing the safety of its metabolites.

Exploring the anti-tumor molecular mechanisms of traditional Chinese medicines has become an important strategy to develop novel anti-tumor drugs in the clinic. Several pharmacological studies have reported the antioxidant, antibacterial, anti-inflammatory, and anti-tumor effects of clove. Previously, we have shown that the active fraction from clove (AFC) can inhibit the growth of tumor cells, particularly colon cancer cells, in vitro. However, the mechanism of action regarding the anti-colon cancer activity of AFC, especially in aerobic glycolysis, has not been adequately investigated. In this study, we found that AFC significantly inhibited the growth of five types of colon cancer cells, downregulated the mRNA and protein levels of M2-type pyruvate kinase (PKM2), and reduced aerobic glycolysis capacity. Transfection of PKM2-siRNA mimicked the inhibitory effects of AFC on aerobic glycolysis in colon cancer cells. Furthermore, the highly expressed, tumor-specific targets c-myc and cyclin D1 in cells were also found to be downregulated following the action of AFC. In the HCT116 cell xenograft nude mice models, the results after AFC administration were consistent with those of the cellular experiments, while AFC caused less liver injury and weight loss than the conventional chemotherapeutic agent 5- fluorouracil (5-FU). In conclusion, AFC inhibits colon cancer growth by downregulating PKM2 to inhibit aerobic glycolysis and reduce the tumor-specific high expression of c-myc and cyclin D1. Future work should explore how it downregulates pyruvate kinase (PK) in the first place, along with the intrinsic mechanism between the downregulation of PKM2 and the downregulation of c-myc.

Four previously undescribed highly oxidized germacrane-type sesquiterpenoid dimers were isolated from Elephantopus tomentosus. Their planar structures and absolute configurations were unequivocally elucidated through comprehensive spectroscopic analysis, combined with experimental electronic circular dichroism (ECD) and time-dependent density functional theory (TDDFT) calculations. These dimers, characterized by an O-ether linkage, represent the first reported examples of such derivatives from the genus Elephantopus. The structural validity was verified by performing Hartree-Fock energy calculations within the quantum mechanical (QM) framework. All isolated sesquiterpenoid dimers exhibited moderate inhibitory activity against human hepatocellular carcinoma cell lines (HepG2 and Hep3B). Notably, compound 4 demonstrated the most significant cytotoxicity, with IC50 values of 1.64 μM (HepG2) and 4.85 μM (Hep3B). Furthermore, compound 4 markedly reduced mitochondrial membrane potential (MMP), indicating its role in inducing apoptosis via mitochondrial dysfunction. Network pharmacology and molecular docking further indicated that compound 4 could interact with HSP90AA1 by binding to key amino acid residues, potentially explaining its pharmacological activity.

The current treatments for triple-negative breast cancer (TNBC) rely mainly on chemotherapy. Enhancing the effect of chemotherapy drugs or exploring new targeted drugs is expected to provide more treatment options for patients with TNBC. Our previous studies have shown that the cystathionine-γ-lyase (CSE) plays an important role in the progression of TNBC. So inhibition of CSE may provide a new direction for the treatment of TNBC. This study aimed to explore the relationship between CSE expression and chemotherapy drug sensitivity, as well as the potential therapeutic role of CSE inhibitor Aurintricarboxylic acid (ATA) in TNBC. The results suggest that the expression of CSE is negatively correlated with the sensitivity of chemotherapy drugs and changes in CSE levels affect the sensitivity of chemotherapy drugs in TNBC cells. The CSE inhibitor ATA has significantly enhanced the sensitivity of chemotherapeutic drugs in MDA-MB-231 cells and 4T1 mouse transplanted tumor model. Further mechanism research has found that ATA enhances the sensitivity of chemotherapeutic drugs via SIRT1-STAT3-C-myc-Bcl-2 signaling pathway in TNBC cells. In addtion, ATA also enhances the sensitivity of chemotherapeutic drugs in TNBC cells by regulating the expression of P-glycoprotein (P-gp), glutathione (GSH) and reactive oxygen species (ROS). These findings suggest that ATA may be a promising therapeutic agent for TNBC treatment by enhancing the sensitivity of chemotherapy drugs through multiple mechanisms.

Non-ribosomal peptide synthetases (NRPSs) are key enzymes in pharmaceutical synthesis, with condensation (C) domains catalyzing amide bond formation between aminoacyl substrates. However, recent research has elucidated that the catalytic capabilities of C domains extend beyond the traditional formation of peptide bonds. In this study, we elucidate the cyclization mechanism of the NRPS-derived natural products hangtaimycin (HTM), characterized by the formation of a 2,5-diketopiperazine (DKP) moiety which involves an intramolecular vinylamide-mediated nucleophilic attack instead of an N-terminal amino group. This cyclization is catalyzed by a terminal condensation-like (CT) domain within the NRPS enzyme HtmB2. We investigated the evolutionary specificity of the HtmB2-CT within Streptomyces spectabilis CCTCC M2017417. Employing a multidisciplinary analytical approach, we have delineated the molecular underpinnings of DKP formation within the HTM biosynthesis. This process is facilitated by residue R2776, which modulates the formation of reactive species and stabilizes the amidate through electrostatic interactions. Besides, we found a positive correlation between the alkaline strength of the residue at position 2776 and the activity of HtmB2-CT. Our study elucidates the formation mechanism of DKPs in NRPS-derived natural products, thereby bridging a critical gap in the structural and mechanistic understanding of this field.