Fig 2: LSD1-mediated H3K4 demethylation in the CD274/CD47 promoter region.A High abundance of H3K4me2 aggregation occurred in the CD274/CD47 promoter region in a variety of tumor cells, including cervical cancer, according to histone ChIP-Seq data from the ENCODE database. B ChIP-Seq performed for SiHa cells also confirmed universal enrichment of H3K4me2 marks in the CD274/CD47 promoter region. C, D Specific sequences targeting the CD274/CD47 promoter region. E ChIP-qPCR indicated that the H3K4me2 level in the CD274 promoter region increased significantly after LSD1 knockdown in SiHa and C33A cells (n = 3 per group); F the H3K4me2 level in the CD47 promoter region underwent the same change (n = 3 per group). ChIP-qPCR experiments were repeated twice. N.S. not significant. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001.

Fig 3: Levels of exosomal CD73 and PD-L1 on-treatment. Exosomes isolated from serum of patients with melanoma during treatment with anti-PD-1 agents at week 4 have significantly increased expression of CD73 (A) or PD-L1 (B) compared with those at baseline (n=15). (C) Total protein content on exosomes isolated from serum of patients at baseline and at week 4 during therapy was determined using the BCA Pierce kit assay. Data are mean±SD. P values are from Wilcoxon matched-pairs signed-rank test (A–B). MP, patients with melanoma; PD-L1, programmed death-ligand 1; RFI, relative fluorescence intensity.

Fig 4: LSD1 inhibitor enhances the efficacy of anti-CD47/PD-L1 immunotherapy therapy in cervical cancer allograft model in vivo.A A combination of LSD1 inhibitors (50 mg/kg, three times a week) and anti-CD47 mAb (100 µg per mouse, three times a week) showed more significant inhibition of tumor growth than single drug administration (n = 4 per group). Evaluation of the appearance (B) and weights (C) of tumors in the four groups demonstrated the enhanced efficacy of anti-CD47 immunotherapy therapy when combined with an LSD1 inhibitor in vivo. D–F Enhanced treatment efficacy was also achieved with a combined administration of LSD1 inhibitors (50 mg/kg, three times a week) and anti-PD-L1 mAb (300 µg per mouse, three times a week) (n = 4 per group). *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.

Fig 5: PD-L1 expression correlates with HIF1-signaling pathway expression in human melanoma. (A) YY-plot showing PD-L1 (CD274) mRNA levels in 375 tumors from cutaneous melanoma patients (TCGA data). Red boxes indicate metastatic tumors; green boxes: primary tumors; and light gray boxes: not determined. (B) Table showing the correlation (R, correlation coefficient) and statistical significance (p-value) of PD-L1 mRNA expression with expression of indicated geneset signatures in the TCGA melanoma data. (C) XY-plots showing three examples from (B)