Archives of biochemistry and biophysics最新文献

{"title":"NADPH gating and F-actin engagement define the structural bases of MICAL1 autoinhibition and activation.","authors":"Federico Ballabio, Agnese Minari, Diane Marie Valerie Bonnet, Andrea Graziadei, Alessio Di Ianni, Maria Nobile, Gabriella Tedeschi, Carlo Camilloni, Antonio Chaves-Sanjuan, Maria Antonietta Vanoni","doi":"10.1016/j.abb.2026.111023","DOIUrl":"https://doi.org/10.1016/j.abb.2026.111023","url":null,"abstract":"<p><p>Human MICAL1 is a multidomain protein exhibiting both an oxidase activity, producing H₂O₂ as a second messenger, and an actin depolymerizing activity through the NADPH-dependent reaction catalyzed by its N-terminal flavoprotein domain. In full-length MICAL1, this domain is inhibited by the following protein regions. Interaction with activating (macro)molecules controls the timing and location of the enzyme activity, explaining its participation in diverse cellular processes. To gain insight into the reaction mechanism and its control, we combined kinetic, cryo-EM, chemical cross-linking and modeling studies of MICAL1, and of complexes with NADPH and F-actin. Contrary to previous models proposing an equilibrium between fully inactive and active conformations, the latter with the properties of the isolated catalytic domain, our results show that MICAL1 exists in solution in a single compact \"autoinhibited\" conformation able to bind and oxidize NADPH, although at a rate lower than that of the isolated catalytic domain. The reorientation of the gating Trp400 residue is required for productive binding of the nicotinamide portion of NADPH for hydride transfer to the FAD coenzyme, and is specifically hampered in full-length MICAL1 by the Trp400-Phe399-Arg933 triad. In complex with F-actin, the isolated flavoprotein domain bridges two adjacent actin subunits along the filament's ridge with the active site in proximity to, but not in direct contact with, the intersubunit actin interface supporting a mechanism of actin residues oxidation through H₂O₂ diffusion from the enzyme active site. Model inspection suggests the conformational changes of full-length MICAL1 required for concomitant F-actin binding and relief of \"autoinhibition\".</p>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":" ","pages":"111023"},"PeriodicalIF":3.5,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149164234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retraction notice to \"Non-thermal atmospheric pressure plasma induces apoptosis in oral cavity squamous cell carcinoma: Involvement of DNA-damage-triggering sub-G₁ arrest via the ATM/p53 pathway\" [Arch. Biochem. Biophys. 545, (2014), 133-140].","authors":"Jae Won Chang, Sung Un Kang, Yoo Seob Shin, Kang Il Kim, Seong Jin Seo, Sang Sik Yang, Jong-Soo Lee, Eunpyo Moon, Seung Jae Baek, Keunho Lee, Chul-Ho Kim","doi":"10.1016/j.abb.2026.111019","DOIUrl":"10.1016/j.abb.2026.111019","url":null,"abstract":"","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":" ","pages":"111019"},"PeriodicalIF":3.5,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149126471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retraction notice to \"MicroRNA-24 inhibits osteosarcoma cell proliferation both in vitro and in vivo by targeting LPAATβ\" [Arch. Biochem. Biophys. 535, (2013), 128-135].","authors":"Lei Song, Jie Yang, Ping Duan, Jianzhong Xu, Xiangdong Luo, Fei Luo, Zehua Zhang, Tianyong Hou, Bing Liue, Qiang Zhoua","doi":"10.1016/j.abb.2026.111015","DOIUrl":"https://doi.org/10.1016/j.abb.2026.111015","url":null,"abstract":"","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":" ","pages":"111015"},"PeriodicalIF":3.5,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149103338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to \"Dasatinib enhances cisplatin sensitivity in human esophageal squamous cell carcinoma (ESCC) cells via suppression of PI3K/AKT and STAT3 pathways\" [Arch. Biochem. Biophys. 575, (2015), 38-45].","authors":"Jie Chen, Tian Lan, Weimin Zhang, Lijia Dong, Nan Kang, Ming Fu, Bing Liu, Kangtai Liu, Cuixiang Zhang, Jincai Hou, Qimin Zhan","doi":"10.1016/j.abb.2026.110985","DOIUrl":"https://doi.org/10.1016/j.abb.2026.110985","url":null,"abstract":"","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":" ","pages":"110985"},"PeriodicalIF":3.5,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148975552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing tumor-associated endothelial cells in clear cell renal cell carcinoma via scRNA-seq and Bulk RNA-seq: construction of a prognostic risk signature.","authors":"Qing Liu, Wenxing Cao, Zhouhua Hao","doi":"10.1016/j.abb.2026.110919","DOIUrl":"https://doi.org/10.1016/j.abb.2026.110919","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Tumor-associated endothelial cells (TAECs) are integral components of the clear cell renal cell carcinoma (ccRCC) microenvironment, but their gene expression-based prognostic value and functional relevance remain to be defined.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Single-cell RNA sequencing (scRNA-seq) data from 7 ccRCC tumors and 5 normal adjacent tissues (GSE156632) were analyzed to identify TAEC subcluster marker genes. A TAEC phenotype score was calculated in the TCGA-ccRCC cohort (n=516) based on the average expression of these markers. Weighted gene co-expression network analysis (WGCNA) was performed to identify gene modules correlated with this score, and module genes were intersected with differentially expressed genes (DEGs) between TCGA tumor and normal tissues. A prognostic risk signature was constructed using LASSO-Cox regression and validated in an external cohort (ICGC RECA-EU + GSE29609). Associations with immune infiltration, pathway activity and drug sensitivity were analyzed. APOLD1-centered pathway analysis was performed using GSVA and PROGENy. Functional validation included qRT-PCR, Western blot, immunofluorescence, Transwell assays, and xenograft models (n=5 mice/group).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;scRNA-seq revealed 8 distinct TAECs subclusters. Integration with TCGA data identified 61 critical TAECs-related genes after intersecting tumor-related DEGs with WGCNA yellow module genes. A 5-gene prognostic signature (TEK, APOLD1, F2RL3, COL5A3, CD248) was established. The model stratified patients into high/low-risk groups with significant survival differences (P&lt;0.0001), achieving 1-/2-/3-year AUCs of 0.755, 0.713, and 0.736 in the TCGA cohort, with external validation AUCs of 0.712, 0.708, and 0.702 in the merged ICGC/GEO cohort. High-risk tumors exhibited metabolic reprogramming (suppressed PPAR signaling), an immunosuppressive TME (enriched M0 macrophages, Tregs, upregulated non-PD-L1 immune checkpoints), and reduced tumor purity. Low-risk tumors retained fatty acid metabolism and anti-tumor immune activation. Drug sensitivity analysis predicted differential sensitivity to targeted therapies and chemotherapeutics between risk groups. APOLD1 was upregulated in ccRCC endothelia (qRT-PCR/Western blot) and induced by ccRCC cell lines (786-O, Caki-1) culture medium in human umbilical vein endothelial cells (HUVECs). APOLD1-high tumors showed enhanced focal adhesion, TGF-β, MAPK, and PI3K pathway activities, and APOLD1 expression was positively correlated with endothelial and angiogenesis-related genes, including KDR, TEK, FLT1, PECAM1, CDH5, VWF, EMCN, ROBO4, and NOTCH4. In HUVECs, ccRCC cell-conditioned medium induced APOLD1 expression, whereas APOLD1 knockdown attenuated SMAD2/3 and ERK phosphorylation. Functionally, APOLD1 knockdown in HUVECs suppressed ccRCC migration/invasion in vitro and xenograft growth in vivo, whereas APOLD1 overexpression in HUVECs promoted ccRCC migration and invasion, f","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":" ","pages":"110919"},"PeriodicalIF":3.5,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148373740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unlocking ferroptosis: A novel link between triple-negative breast cancer and immune regulation","authors":"Laura Montero-León ,&nbsp;Alfredo Cruz-Gregorio ,&nbsp;Estefani Yaquelin Hernández-Cruz ,&nbsp;Edda Sciutto ,&nbsp;Gladis Fragoso ,&nbsp;José Pedraza-Chaverri","doi":"10.1016/j.abb.2026.110760","DOIUrl":"10.1016/j.abb.2026.110760","url":null,"abstract":"<div><div>Breast cancer is the most diagnosed malignant tumor worldwide and remains the leading cause of cancer-related death among women. Among its subtypes, triple-negative breast cancer (TNBC) is the most aggressive form, resulting in limited treatment options and a poorer prognosis. The development of novel therapeutic strategies is both urgent and challenging. Ferroptosis is a recently identified form of regulated cell death that is iron-dependent and characterized by the abnormal accumulation of lipid peroxides and iron ions. Ferroptosis is critical for tumorigenesis, progression, metastasis, and therapeutic resistance in breast cancer, positioning its modulation as a promising complementary strategy. Furthermore, the tumor microenvironment is affected by either inhibiting or inducing ferroptosis in immune cells—promoting tumor proliferation, therapeutic resistance, or, in combination with radiotherapy, antioxidants, or ferritinophagy activators, facilitating tumor eradication. Despite the expanding literature on ferroptosis and cancer, a critical gap remains in understanding how ferroptosis operate in tumor cells versus immune cells within the TNBC microenvironment. This lack of integration hampers the rational design of therapeutic strategies that induce ferroptosis in cancer cells while preserving- or enhancing-antitumor immunity. This review addresses this gap by providing a unified framework linking ferroptosis, immune regulation, and emerging therapeutic strategies in TNBC.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"779 ","pages":"Article 110760"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146148959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discovery and functional validation of a gut microbiota-metabolite-miRNA axis in diabetic encephalopathy","authors":"Haitian Sun ,&nbsp;Jingzhi Liu ,&nbsp;Yanxiao Jing ,&nbsp;Guanghong Li ,&nbsp;Xinhuan Zhang","doi":"10.1016/j.abb.2026.110759","DOIUrl":"10.1016/j.abb.2026.110759","url":null,"abstract":"<div><h3>Background</h3><div>Diabetic encephalopathy (DE), a severe neurological complication of diabetes, is characterized by cognitive decline and neuronal damage. While gut microbiota dysbiosis has been implicated in diabetes pathogenesis, its specific role and molecular mechanisms in DE remain unclear.</div></div><div><h3>Methods</h3><div>A multi-omics approach integrating 16S rRNA sequencing and untargeted metabolomics was performed on fecal samples from 29 DE patients and 31 diabetic controls (DM). An in vitro DE model was established using high glucose (HG)-treated HT22 cells, which were further incubated with sterile fecal microbiota supernatant (FMS) from DE patients. Neuronal viability, apoptosis, oxidative stress markers (SOD, MDA, ROS), and miR-493-3p expression were assessed. The miR-493-3p/RAF1 interaction was validated using dual-luciferase reporter assays and Western blot.</div></div><div><h3>Results</h3><div>No significant differences in overall microbial diversity were identified in DE and DM cohorts. However, DE patients exhibited distinct gut microbiota composition, with elevated Verrucomicrobiotaand Bacteroidota, and reduced Proteobacteriaand Firmicutes. Metabolomic analysis revealed 160 differentially abundant metabolites enriched in amino acid and lipid metabolism pathways. In vitro, DE-derived FMS dose-dependently exacerbated HG-induced neuronal oxidative damage and apoptosis, concomitant with miR-493-3p upregulation. Inhibition of miR-493-3p attenuated these damaging effects and restored RAF1 expression. RAF1 was confirmed as a direct target of miR-493-3p, and its downregulation was critical in mediating FMS-induced neuronal injury.</div></div><div><h3>Conclusion</h3><div>This study identified a novel gut-brain axis pathway in DE, whereby gut microbiota dysbiosis and metabolic alterations promote neuronal damage via the miR-493-3p/RAF1 signaling axis. These findings provide new insights into DE pathogenesis and suggest potential therapeutic targets for this debilitating complication.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"779 ","pages":"Article 110759"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146130874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EGFR and IRE1α pathways are associated with distinct immunomodulatory gene expression profiles in NSCLC cells with acquired resistance to EGFR TKIs","authors":"Yi-Shiuan Wang ,&nbsp;Hsiu-Chuan Chou ,&nbsp;En-Chi Liao ,&nbsp;Hsin-Yi Chen ,&nbsp;Meng-Wei Lin ,&nbsp;Yu-Shan Wei ,&nbsp;Li‐Hsun Lin ,&nbsp;Yi-Ru Chang ,&nbsp;Han Meng ,&nbsp;Yueh-Feng Wen ,&nbsp;Hong-Lin Chan","doi":"10.1016/j.abb.2026.110762","DOIUrl":"10.1016/j.abb.2026.110762","url":null,"abstract":"<div><div>EGFR-TKI-resistant cell lines were established by long-term exposure to gefitinib, afatinib, and osimertinib via the PC9 model. This model helps study EGFR-TKI resistance mechanisms in non-small cell lung cancer (NSCLC) and may offer insights to improve treatment outcomes, particularly for patients unresponsive to anti-PD-1/PD-L1 therapies. We investigated molecular alterations in these resistant cell lines using multi-omics techniques, including genome sequencing, proteomics, and transcriptomics.</div><div>Differential dependencies on EGFR downstream pathways were observed among resistant cell lines. Immune evasion mechanisms were analyzed to identify alterations in EGFR downstream pathways and unfolded protein response (UPR) elements contributing to immune-related transcriptional patterns. Afatinib-resistant cells exhibited the most pronounced immunosuppressive-like transcriptional features compared to gefitinib- and osimertinib-resistant cells. This was characterized by elevated PD-L1 expression, minimal changes in MHC class 1 levels, down-regulation of shared immune-modulated gene sets, and a cytokine profile favoring immunosuppression (e.g., lower IL-6, CXCL10, IFN-γ, CCL22; higher IL-8). These findings suggest a poor prognosis and limited efficacy of anti-PD-1/PD-L1 immunotherapy in NSCLC patients with similar resistance profiles. Notably, inhibition of IRE1α signaling partially reversed this immunosuppressive-like transcriptional signature, indicating a potential strategy to restore immune responsiveness in afatinib-resistant NSCLC. Our study underscores the distinct remodeling effects of different EGFR-TKIs on tumor-cell–intrinsic immunoregulatory pathways. Targeting endoplasmic reticulum (ER) stress pathways alongside immune checkpoint inhibitors may be crucial for overcoming resistance mechanisms identified here. These insights provide a rationale for personalized treatment strategies tailored to the immune-related gene-expression profiles observed in EGFR-TKI–resistant NSCLC models, aiming to enhance therapeutic responses and improve clinical outcomes.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"779 ","pages":"Article 110762"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146163819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Echinoderm collagen as a neuromodulatory antioxidant: biochemical characterization and molecular interaction with NMDA receptor","authors":"Rozirwan ,&nbsp;Yoga Winarta ,&nbsp;Isnaini ,&nbsp;Wike Ayu Eka Putri ,&nbsp;Fauziyah ,&nbsp;Riris Aryawati ,&nbsp;Nadila Nur Khotimah ,&nbsp;Melki ,&nbsp;Redho Yoga Nugroho ,&nbsp;Chaidir","doi":"10.1016/j.abb.2026.110758","DOIUrl":"10.1016/j.abb.2026.110758","url":null,"abstract":"<div><div>Marine collagen is increasingly recognized as a sustainable biomaterial for therapeutic applications; however, collagen derived from tropical Echinodermata remains underexplored, particularly in the context of neuropharmacology. This study investigated the biochemical characteristics, antioxidant activity, and neuromodulatory potential of collagen isolated from three tropical echinoderm species, <em>Holothuria atra</em>, <em>Acanthaster planci</em>, and <em>Culcita novaeguineae</em>, collected from the neritic zone of Pahawang Island, Indonesia. The isolated collagens exhibited very strong antioxidant activity, with IC₅₀ values of 4.43 (<em>C. novaeguineae</em>), 10.84 (<em>H. atra</em>), and 21.78 μg/mL (<em>A. planci</em>), surpassing several previously reported marine collagen sources. Structural characterization using Liquid Chromatography-Mass Spectrometry (LC-MS), Fourier Transform Infrared Spectroscopy (FTIR), and Carbon-13 Nuclear Magnetic Resonance (¹³C NMR) revealed glutamic acid, proline, glycine, and valine as dominant amino acid residues, supporting the stability and functional integrity of the collagen matrix. Furthermore, <em>in silico</em> molecular docking analysis demonstrated a favorable interaction between glutamic acid and the N-Methyl-<span>d</span>-Aspartate (NMDA) receptor GluN1a/GluN2B (PDB ID: <span><span>4PE5</span><svg><path></path></svg></span>), with a binding affinity of ΔG = −5.25 kcal/mol and an inhibition constant (Ki) of 142.02 μM, indicating a potential neuromodulatory mechanism. By integrating biochemical characterization with molecular interaction analysis, this study provides the first evidence that collagen from tropical echinoderms exhibits dual antioxidant and neuromodulatory potential, highlighting its promise as a sustainable marine-derived biomaterial for neurodegenerative disease-related drug discovery.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"779 ","pages":"Article 110758"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of an N-methylpyrazole derivative as a selective inhibitor of breast cancer resistance protein (BCRP/ABCG2)","authors":"Andrezza Braiane Ferreira Siridó ,&nbsp;Arthur Henrique Gomes de Oliveira ,&nbsp;Julia Poletto ,&nbsp;Thales Kronenberger ,&nbsp;Fabiane Gomes de Moraes Rego ,&nbsp;Geraldo Picheth ,&nbsp;Marc Le Borgne ,&nbsp;Ahcène Boumendjel ,&nbsp;Fernanda Andreia Rosa ,&nbsp;Glaucio Valdameri ,&nbsp;Vivian Rotuno Moure","doi":"10.1016/j.abb.2026.110761","DOIUrl":"10.1016/j.abb.2026.110761","url":null,"abstract":"<div><div>Multidrug resistance (MDR) mediated by ATP-binding cassette (ABC) transporters remains a major obstacle to cancer chemotherapy, particularly at later disease stages with metastases. Among the 48 human ABC proteins, P-glycoprotein (P-gp/ABCB1), multidrug resistance-associated protein 1 (MRP1/ABCC1), and breast cancer resistance protein (BCRP/ABCG2) are the most studied ABC transporters associated with MDR. Inhibition of ABC transporters has been considered as one possible strategy to overcome MDR. In this study, twelve N-methylpyrazole derivatives were evaluated as inhibitors of ABCB1, ABCC1, and ABCG2. Several compounds selectively inhibited ABCG2 while showing no activity against ABCB1 or ABCC1. The most potent derivative, <strong>1l</strong>, inhibited more than 50% of ABCG2 activity at 10 μM and displayed substrate-independent inhibition, with IC₅₀ values ranging from 1.6 to 3.8 μM depending on the fluorescent probe used. Compound <strong>1l</strong> exhibited only mild cytotoxicity and was not transported itself by ABCG2. Mechanistic studies revealed that <strong>1l</strong> induced conformational changes in ABCG2, as evidenced by increased binding of the 5D3 conformational antibody. Combination assays with established ABCG2 inhibitors, including chromone <strong>4a</strong> and indeno-[1,2-<em>b</em>]indole <strong>5e</strong>, showed neither synergistic nor antagonistic effects. Induced-fit docking simulations supported the experimental data, indicating that <strong>1l</strong> binds within the central transmembrane cavity of ABCG2, engaging key residues such as Phe439 and stabilizing inward-facing conformations. Finally, co-treatment with <strong>1l</strong> restored sensitivity of ABCG2-overexpressing cells to the anticancer drug SN38, effectively reversing the MDR phenotype. Collectively, these results identify N-methylpyrazole derivatives as promising selective inhibitors of ABCG2.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"779 ","pages":"Article 110761"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}