Figure 1.

SMARCA4 deficiency leads to decreased response to anti-PD-1 immunotherapy and impaired immune cell infiltration into tumors in humanized xenograft models. A, Schematic representation detailing the development of the humanized mouse model. Parental and SMARCA4 KO H2122 tumors were introduced into humanized mice at 6 weeks after human CD34⁺ stem cells implantation, with a minimum of 25% huCD45⁺ cells observed in peripheral blood. Parental xenograft models were subjected to i.p. injections of vehicle or pembrolizumab (250 μg/mouse) every 3 days for 3 weeks, whereas SMARCA4 KO xenograft models were treated in the same manner but for 2 weeks. B, Immunoblots of parental and SMARCA4 KO H2122 cell lysates stained using anti-SMARCA4 and β-actin antibodies. Protein molecular weight markers are in kilodaltons (kDa). C and D, Growth curves of parental H2122 xenograft models (n = 6 animals per group; C) or SMARCA4 KO H2122 xenograft models (n = 5 animals per group; D) after treatment with isotype control antibodies or anti-PD-1 antibodies were generated. Data points represent the mean ± SEM. *, P < 0.05, two-sided unpaired t test. E–K, The cells isolated from dissociated subcutaneous parental and SMARCA4 KO H2122 xenograft models were analyzed by flow cytometry. E–G, Flow cytometry plot of HLA-DR+ DCs (E). The percentage of HLA-DR+ DCs out of CD11b⁺ cells (F) and CD103⁺ cells out of CD3⁻CD19⁻ cells (G). H–K, Flow cytometry plot of CD4⁺ T cells and CD8⁺ T cells (H and I). The percentage of CD4⁺ T cells (J) and CD8⁺ T cells (K) out of CD3⁺ T cells. Data points represent the mean ± SEM. *, P < 0.05; **, P < 0.01, one-tailed Mann–Whitney test. ns, not significant. (A, Created with BioRender.com.)