Journal: Journal of Nanobiotechnology

Article Title: Targeting taurine metabolism via PROTAC-mediated SLC6A6 degradation potentiates photodynamic therapy and reverses immunosuppression in cholangiocarcinoma

doi: 10.1186/s12951-026-04592-y

Figure Lengend Snippet: Schematic illustration of the synthesis process and therapeutic mechanism of the CM-TAC@Ce@PEG nanosystem. CM-TAC@Ce@PEG is a ROS-responsive and tumor-targeting nanosystem, composed of PPS-PEG polymers coated with tumor cell membranes to enable homologous targeting. The system co-delivers the SLC6A6-degrading AbTAC and the photosensitizer Ce6, facilitating synergistic disruption of taurine metabolism and photodynamic therapy PDT for enhanced antitumor efficacy. During treatment, CM-TAC@Ce@PEG synergistically amplifies oxidative stress and lipid peroxidation to promote ferroptosis and initiates an antitumor immune response. The combination of taurine metabolic disruption and PDT demonstrates significant potential to reprogram the immunosuppressive TME in CCA by promoting macrophage polarization towards the pro-inflammatory M1 phenotype and reducing the immunosuppressive M2 phenotype, while simultaneously enhancing the functional activity of CD8⁺ T cells. This strategy exhibits considerable promise for advancing CCA immunotherapy

Article Snippet: The anti‐taurine transporter (SLC6A6) antibody was acquired from Alomone Labs (Jerusalem, Israel).

Techniques: Polymers, Disruption, Functional Assay, Activity Assay

Journal: Journal of Nanobiotechnology

Article Title: Targeting taurine metabolism via PROTAC-mediated SLC6A6 degradation potentiates photodynamic therapy and reverses immunosuppression in cholangiocarcinoma

doi: 10.1186/s12951-026-04592-y

Figure Lengend Snippet: SLC6A6 is highly expressed in tumor tissues of CCA and regulates taurine uptake to modulate PDT efficacy. ( A ) Pan-cancer analysis of SLC6A6 expression across cancer types from the TCGA dataset. Abbreviations: BLCA, bladder urothelial carcinoma; BRCA, breast invasive carcinoma; CHOL, cholangiocarcinoma; CECS, cervical squamous cell carcinoma and endocervical adenocarcinoma; COAD, colon adenocarcinoma; COADREAD, colon adenocarcinoma/rectum adenocarcinoma esophageal carcinoma; ESCA, esophageal carcinoma; GBM, glioblastoma multiforme; GBMLGG, glioma; HNSC, head and neck squamous cell carcinoma; KICH, kidney chromophobe; KIRC, kidney renal clear cell carcinoma; KIRP, kidney renal papillary cell carcinoma; KIRPAN, pan-kidney cohort (KICH + KIRC + KIRP); LIHC, liver hepatocellular carcinoma; LUAD, lung adenocarcinoma; LUSC, lung squamous cell carcinoma; LGG, brain lower grade glioma; PRAD, prostate adenocarcinoma; PAAD, pancreatic adenocarcinoma; PCPG, pheochromocytoma and paraganglioma; READ, rectum adenocarcinoma; STAD, stomach adenocarcinoma; STES, stomach and esophageal carcinoma; THCA, thyroid carcinoma; UCEC, uterine corpus endometrial carcinoma. ( B , C ) Western blot analysis and immunohistochemistry staining of SLC6A6 expression levels in CCA tissues and matched non-tumor tissues; N, normal liver tissue; T, tumor tissue; n = 6 per group. Scale bar, 100 μm. ( D ) Western blot analysis of SLC6A6 expression levels in human cholangiocarcinoma cell lines and a human normal cell line; n = 3 independent biological replicates. ( E ) The correlation between SLC6A6 protein level and taurine concentration in tissues; n = 12; Pearson’s correlation test. ( F ) Analysis of SLC6A6 expression in the PDT-treated CCA dataset GSE84756 . ( G , H ) Representative fluorescence images of ROS and quantitative analysis of fluorescence intensity in HuCCT-1 cells following various treatments. Scale bar, 100 μm. ( I , J ) Flow cytometric analysis of ROS generation in HuCCT-1 cells after different treatments; n = 3 per group. ( K , L ) Apoptosis analysis of HuCCT-1 cells by flow cytometry using Annexin V-FITC and 7-AAD staining; n = 3 per group. ( M , N ) Representative fluorescence images and quantitative analysis of Calcein AM/PI-stained HuCCT-1 cells after various treatments. Scale bar, 100 μm. ( O ) Flow cytometric analysis of dead HuCCT-1 cells following different treatments; n = 3 per group. Tau, taurine; ns, not significant; *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001

Article Snippet: The anti‐taurine transporter (SLC6A6) antibody was acquired from Alomone Labs (Jerusalem, Israel).

Techniques: Analysis, Expressing, Western Blot, Immunohistochemistry, Staining, Tissue, Concentration Assay, Fluorescence, Flow Cytometry, FACS, Knockdown

Journal: Journal of Nanobiotechnology

Article Title: Targeting taurine metabolism via PROTAC-mediated SLC6A6 degradation potentiates photodynamic therapy and reverses immunosuppression in cholangiocarcinoma

doi: 10.1186/s12951-026-04592-y

Figure Lengend Snippet: Fabrication, characterization, and ROS-responsive degradation of CM-TAC@Ce@PEG. ( A ) Schematic diagram of the AbTAC structure. ( B ) Binding affinities of AbTAC to the SLC6A6 protein fragment (564–620 aa) as determined by SPR. ( C ) Western blot analysis of SLC6A6 protein levels following treatment with AbTAC at various time points; n = 3 independent biological replicates. ( D ) HuCCT-1 cells were treated with PBS or 100 nM AbTAC for 24 h. Cell lysates were subjected to immunoprecipitation using an anti-SLC6A6 antibody; n = 3 independent biological replicates. ( E ) Peptides dissolved in double-distilled H 2 O were applied to the nitrocellulose membrane, followed by immunoblotting with AbTAC. ( F ) Schematic illustration of the synthesis route for CM-TAC@Ce@PEG. ( G ) Representative transmission electron microscopy (TEM) images of PPS-PEG, TAC@Ce@PEG, and CM-TAC@Ce@PEG. Scale bar, 100 nm. ( H , I ) Particle sizes and zeta potentials of PPS-PEG, Ce@PEG, TAC@PEG, TAC@Ce@PEG, and CM-TAC@Ce@PEG, as measured by dynamic light scattering (DLS). ( J ) Particle size and polydispersity index (PDI) of CM-TAC@Ce@PEG in mouse serum. ( K ) Fluorescence emission spectra of Ce@PEG, TAC@Ce@PEG, and CM-TAC@Ce@PEG. ( L ) UV-vis-NIR absorption spectra of AbTAC, PPS-PEG, Ce@PEG, TAC@PEG, TAC@Ce@PEG, and CM-TAC@Ce@PEG. ( M ) Representative TEM images of TAC@Ce@PEG following 660 nm laser irradiation (0.2 W cm⁻ 2 , 5 min). Scale bar, 100 nm. ( N ) Cumulative AbTAC release profile from CM-TAC@Ce@PEG under 660 nm laser irradiation (0.2 W cm⁻ 2 , 5 min). ( O ) Absorption spectra of 1,3-diphenylisobenzofuran (DPBF) after treatment with CM-TAC@Ce@PEG under 660 nm laser irradiation (0.2 W cm⁻ 2 ) at various time points. ( P ) Sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis of tumor cell membrane proteins, PPS-PEG, TAC@Ce@PEG, and CM-TAC@Ce@PEG. ( Q ) FITC labeled CM-TAC@Ce@PEG cellular uptake at different time points using confocal laser scanning microscopy (CLSM), and DAPI was applied to represent the nucleus. Scale bar: 10 μm. ( R ) Representative CLSM images of MIHA and HuCCT-1 cells at various time points after incubation with CM-TAC@Ce@PEG (20 μg mL⁻ 1 ). Red: Ce6; green: cytoskeleton; blue: nucleus. Scale bar: 10 μm

Article Snippet: The anti‐taurine transporter (SLC6A6) antibody was acquired from Alomone Labs (Jerusalem, Israel).

Techniques: Binding Assay, Western Blot, Analysis, Immunoprecipitation, Membrane, Transmission Assay, Electron Microscopy, Dynamic Light Scattering Assay, Fluorescence, Irradiation, Polyacrylamide Gel Electrophoresis, SDS Page, Labeling, Confocal, Laser-Scanning Microscopy, Incubation, Immunofluorescence

Journal: Journal of Nanobiotechnology

Article Title: Targeting taurine metabolism via PROTAC-mediated SLC6A6 degradation potentiates photodynamic therapy and reverses immunosuppression in cholangiocarcinoma

doi: 10.1186/s12951-026-04592-y

Figure Lengend Snippet: CM-TAC@Ce@PEG mediates tumor cell death through the ferroptosis pathway. ( A ) Viability of HuCCT-1 cells pretreated with different programmed cell death inhibitors followed by CM-TAC@Ce@PEG + L, as measured by CCK-8 assay; n = 4 per group. ( B ) Transcriptomic profiles of HuCCT-1 cells treated with CM-Ce@PEG + L and CM-TAC@Ce@PEG + L. Differentially expressed genes were selected using thresholds of |fold change|> 2 and P-value < 0.05. Red, upregulated; green, downregulated. ( C ) Signaling pathway enrichment analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) in CM-TAC@Ce@PEG + L-treated HuCCT-1 cells. ( D ) Western blot analysis of ferroptosis-related proteins in HuCCT-1 cells after different treatments; n = 3 independent biological replicates. ( D ) Transmission electron microscopy (TEM) images of HuCCT-1 cells following various treatments. Scale bars: 500 nm (upper) and 200 nm (lower). ( F , G , H ) Relative levels of MDA, GSH, and Fe 2 ⁺ in HuCCT-1 cells after different treatments; n = 3 per group. ( I , J ) Flow cytometric analysis and representative fluorescence images of lipid peroxidation measured by C11-BODIPY in HuCCT-1 cells after different treatments; n = 3 per group. ( K ) Representative immunohistochemical (IHC) staining images of tumor sections from mice receiving different treatments, using indicated antibodies. Scale bars: 100 μm. ns, not significant; *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001

Article Snippet: The anti‐taurine transporter (SLC6A6) antibody was acquired from Alomone Labs (Jerusalem, Israel).

Techniques: CCK-8 Assay, Analysis, Western Blot, Transmission Assay, Electron Microscopy, Fluorescence, Immunohistochemical staining, Immunohistochemistry, RNA Sequencing, Transmission Electron Microscopy, Flow Cytometry, Immunofluorescence

Journal: Journal of Nanobiotechnology

Article Title: Targeting taurine metabolism via PROTAC-mediated SLC6A6 degradation potentiates photodynamic therapy and reverses immunosuppression in cholangiocarcinoma

doi: 10.1186/s12951-026-04592-y

Figure Lengend Snippet: ALOXE3 silencing affects lipid peroxidation and is regulated by GATA3 phosphorylation. ( A ) HuCCT-1 cells were transfected for 48 h with siControl or siALOXE3, followed by treatment with CM-TAC@Ce@PEG + L. Protein levels of indicated markers were analysed by western blot; n = 3 independent biological replicates. ( B , C , D ) Relative levels of malondialdehyde (MDA), glutathione (GSH), and Fe 2 ⁺ in HuCCT-1 cells after different treatments; n = 3 per group. ( E ) Flow cytometric analysis of lipid peroxidation using C11-BODIPY in HuCCT-1 cells following various treatments; n = 3 per group. ( F ) Predicted binding sites of GATA3 on the ALOXE3 promoter region, as identified using the JASPAR database. ( G ) Dual-luciferase reporter assay evaluating the interaction between ALOXE3 and GATA3; n = 5 per group. Firefly luciferase activity was normalised to renilla luciferase activity, which served as an internal control for transfection efficiency. ( H ) Western blot analysis of indicated proteins after different treatments; n = 3 independent biological replicates. ( I ) Relative MDA levels in HuCCT-1 cells after different treatments; n = 3 per group. ( J , K ) Flow cytometric analysis of lipid peroxidation using C11-BODIPY in HuCCT-1 cells following various treatments; n = 3 per group. ( L ) HuCCT-1 cells were transfected for 48 h with siControl, siGATA3, or siGATA3 + oeALOXE3, then treated with CM-TAC@Ce@PEG + L. Protein expression of indicated markers was determined by western blot; n = 3 independent biological replicates. ( M ) Schematic model illustrating the mechanism of ferroptosis induction in tumor cells by CM-TAC@Ce@PEG + L. ns, not significant; *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001

Article Snippet: The anti‐taurine transporter (SLC6A6) antibody was acquired from Alomone Labs (Jerusalem, Israel).

Techniques: Phospho-proteomics, Transfection, Western Blot, Analysis, Binding Assay, Luciferase, Activity Assay, Control, Expressing, Flow Cytometry