Journal: Journal for Immunotherapy of Cancer
Article Title: SOX2 promotes resistance of melanoma with PD-L1 high expression to T-cell-mediated cytotoxicity that can be reversed by SAHA
doi: 10.1136/jitc-2020-001037
Figure Lengend Snippet: Epigenetic compounds library screen identified SAHA decreased SOX2 level and eliminated SOX2-dependent tumor growth. (A) Schematic illustration of the screen strategy. MM200 cells were treated with 1000 IU/mL IFNγ and 5 µM epigenetic inhibitors for 24 hours, then the protein level of SOX2 was assessed by western blot assay. (B) Change of SOX2 protein level and mRNA according to Western blot and qPCR assay. ME4405 cells were treated with or without 5 µM SAHA for 24 hours. (C, D) Histogram of the percentage of cleaved caspase-3 positive cells assessed by flow cytometry. Vector and SOX2 OE ME4405 and MM200 cells were treated with or without 5 µM SAHA for 24 hours and then cocultured with T cells for 6–8 hours (Tumor: T=10:1). (E) The in vivo experimental layout. (F, G) Tumor growth curve and xenografts weight of melanoma tumors from C57BL/6 mice (control and SAHA, n=8). (H, K, L, O) Percentage of CD8+ T, NK, CD4+ T and Treg T cells in TILs for each group. (I, J, M, N) Percentage cytotoxic CD8+ T in total CD8+ T cells and cytotoxic CD4+ T in total CD4+ T cells. Tumor: T, Tumor cells: T cells. Error bars indicate SEM. One-way ANOVA test. NS, not significant; TILs, tumor infiltrating lymphocytes; *** p<0.001, ** p<0.01, * p<0.05.
Article Snippet: The epigenetic compounds library, inhibitors and cytokines are as listed: epigenetic compounds library (No. L1900, Selleck Chemicals, Houston, TX, USA), SAHA (No. S1047, Selleck Chemicals), Etidronate (No. S1857, Selleck Chemicals), PTP1B inhibitor (No. T4256, TargetMol, Boston, MA, USA), protein tyrosine phosphatase (PTP) inhibitor I (No. T7084, TargetMol), SPI 112 (No. T4340, TargetMol), murine IFNγ (No. 315-05-100, PeproTech, Rocky Hill, NJ, USA), human IFNγ (No. 300-02-1000, PeproTech), human IL2 (No. 200-02-100, PeproTech), antimouse PD-1 (CD279) (No. BE0146, BioXCell, West Lebanon, NH, USA), Rat IgG2a isotype control (No. BE0089, BioXCell).
Techniques: Western Blot, Flow Cytometry, Plasmid Preparation, In Vivo, Control