Fig. 8: Intratumoral delivery of PEI/PC7A/siNAT10 nanoparticles for cancer immunotherapy.

A The diagram of PEI/PC7A and its size distribution. B Confocal image showing the uptake of PEI/PC7A. TC1 tumor cells were cultured in chamber slides overnight, and then added with 20 nM FAM-labeled siRNA for 4 h. Cells were stained with 50 nM Lyso-Tracker Red (Beyotime, catalog C1046) and 10 µg/mL Hoechst (Beyotime, catalog C1022) for 30 min. Immunofluorescence images were acquired using a Nikon A1 fluorescence microscope. C The mRNA expression levels of NAT10 were measured using RT-PCR in TC1 tumor cells with or without siRNA. 2×10⁵ TC1 tumor cells were seeded in 12-well plates overnight. The medium was then replaced with Opti-MEM, and PEI/PC7A was added with a final siRNA concentration of 20 nM (n = 3 biologically independent samples). The data are compared using the two-sided Student’s t test; **P = 0.006. D Protein expression levels of NAT10 were determined by Western blotting in TC1 (left panel) and MCA205 (right panel) tumor cells treated with or without PEI/PC7A/siNAT10 nanoparticles. E Tumor weight for C57BL/6 N mice (n = 5 mice per group) inoculated with TC1 tumor cells treated with Remodelin or PEI/PC7A/siNAT10 nanoparticles. TC1 tumor cells were inoculated subcutaneously into C57BL/6 N mice. Mice received Remodelin via oral gavage for the first 7 days at a dose of 100 mg/kg. PEI/PC7A containing siRNA (5 nmol/kg) was dissolved in PBS and injected into the tumor on days 4, 7, and 9. Tumor tissues were harvested after sacrificing the mice. Representative images are shown in the left panel. Statistical significance was determined using One-way ANOVA; from left to right, ** P = 0.0006; *P = 0.0183. F Tumor weight for C57BL/6 N mice (n = 5 mice per group) inoculated with TC1 tumor cells treated with PEI/PC7A/siRNA nanoparticles and/or anti-PD-1 antibodies. TC1 tumor cells were inoculated subcutaneously into C57BL/6 N mice. PEI/PC7A/siNAT10 nanoparticles or saline were injected into the tumor on days 4, 7, and 9. On day 8, mice were treated with IgG control or anti-PD-1 antibodies. Statistical significance was determined using One-way ANOVA; from left to right, *** P < 0.001; **P = 0.0092. G Representative immunofluorescence staining of CD8⁺ T cells in TC1 tumor tissues. Tumor tissues from C57BL/6 N mice (F) were subjected to immunostaining analysis for CD8⁺ T cells (red) and nucleus (blue). CD8⁺ T cells were quantified by counting positive signals in 3 randomly selected fields (20×) per tumor section using Image J. Statistical analysis was conducted using One-way ANOVA, Scale bar, 100 µm; n = 15 biologically independent samples. Statistical significance was determined using One-way ANOVA; from left to right, *** P < 0.001; ***P = 0.0007. H FACS analysis of the proportions of IFN-γ⁺CD8⁺ immune cells in TC1 tumor tissues. Tumor tissues from C57BL/6 N mice (F) were subjected to FACS analysis for IFN-γ⁺CD8⁺ immune cell populations (n = 5 mice per group). Statistical significance was determined using One-way ANOVA; from left to right, *** P = 0.0007; **P = 0.0046. I Diagram illustrating how tumor-intrinsic NAT10 orchestrates immune evasion and regulates antitumor immunity. Tumor-intrinsic NAT10 directly acetylated Myc mRNA, enhancing Myc transcription and subsequently promoting CDK2 expression, which in turn upregulates DNMT1 and drives cell proliferation. However, inhibition of NAT10 downregulates the MYC/CDK2/DNMT1 pathway, leading to increased formation of dsRNA and triggering RIG-I-mediated IFN-I response. This activation of the innate immune response enhances CD8⁺ T cell mediated antitumor immunity, offering a potential therapeutic avenue for boosting immune surveillance in cancer. Unless specified otherwise, the data are presented as means ± SEM (error bar). Source data are provided as a Source Data file.