Fig. 1: Abnormal KDM5B expression promotes proliferation, invasion and cisplatin resistance of NPC cells.

a The flow chart of how to identify KDM5B responsible for regulating histone methylation in NPC. b The bar chart showing the 29 genes ranking according to Log2FC value. c, d Differential expression analyses of KDM5B between tumor and normal tissues in GSE118719 (c) and GSE53829 (d) datasets. e, f HNE1 and CNE2 cells infected with lentivirus vectors expressing KDM5B specific shRNAs or shKDM5B + KDM5B plasmid, after puromycin selection cells were harvested for Western blotting analysis (e), RT-qPCR analysis (e), CCK-8 assay (f). Statistical significance was determined by one-way ANOVA followed by Tukey’s multiple comparisons test. Data presented as Mean ± SD with three replicates. NS not significant; **P < 0.01; ***P < 0.001. g HNE1 cells were transfected with indicated constructs. After puromycin selection, cells were injected subcutaneously into the nude mice for xenografts assay. Tumor volumes were measured every 3 days. Tumors were harvested, photographed, and weighed. Statistical significance was determined by one-way ANOVA followed by Tukey’s multiple comparisons test. Data presented as Mean ± SD with five replicates. *P < 0.05; **P < 0.01; ***P < 0.001. h–j HNE1 and CNE2 cells were infected with shControl or shKDM5B plasmid for 48 h. then cells were treated with or without cisplatin (4 μg/ml) for another 48 h. Cells were collected for fluorescein isothiocyanate (FITC)/PI flow cytometry (h, i) and CCK-8 assay (j). Statistical significance was determined by one-way ANOVA followed by Tukey’s multiple comparisons test. Data presented as Mean ± SD with three replicates. **P < 0.01; ***P < 0.001. k HNE1 and CNE2 cells were infected with shControl or shKDM5B for 72 h. Cells were treated with a serial dose of cisplatin. Then, these cells were collected for CCK-8 assay and subjected to measure the IC₅₀ values of cisplatin. l HNE1 and CNE2 cells were transfected with EV or myc-KDM5B for 72 h. Cells were treated with a serial dose of cisplatin. Then, these cells were collected for CCK-8 assay and subjected to measure the IC₅₀ values of cisplatin. Statistical significance was determined by one-way ANOVA followed by Tukey’s multiple comparisons test. Data presented as Mean ± SD with three replicates. m HNE1 cells were transfected with indicated constructs. After puromycin selection, cells were injected subcutaneously into the nude mice for xenografts assay. These mice were treated with or without cisplatin (5 mg·kg⁻¹·day⁻¹, 10 days). Tumor volumes were measured every 3 days. Tumors were harvested, photographed, and weighed. Statistical significance was determined by one-way ANOVA followed by Tukey’s multiple comparisons test. Data presented as Mean ± SD with six replicates. *P < 0.05; ***P < 0.001.