Fig. 1: RBM30 upregulates programmed death ligand 1 (PD-L1) expression in hepatocellular carcinoma (HCC). | Oncogene

Fig. 1: RBM30 upregulates programmed death ligand 1 (PD-L1) expression in hepatocellular carcinoma (HCC).

From: RBM30 recruits DOT1L to activate STAT1 transcription and drive immune evasion in hepatocellular carcinoma

Fig. 1

A RBM1–48 were overexpressed in Huh-7 cells and verified using Western blotting assays. Further detection revealed that only when RBM12/RBM30 was overexpressed, the PD-L1 expression was increased. B Knockout of RBM30 reduced the protein expression and messenger RNA (mRNA) content of PD-L1 in Lm3 cells. The PD-L1 level in Hep3B cells was noticeably increased after the overexpression of RBM30 (n = 3, ***P < 0.0001). C Fluorescence-Activated Cell Sorting (FACS) assays were applied to detect the surface PD-L1 expression of HCC cells, demonstrating that elimination of RBM30 reduced the expression of PD-L1 on the membrane surface of HepG2 cells, whereas overexpression of RBM30 in Hep3B cells upregulated the content of PD-L1 on the membrane surface of Hep3B cells (n = 3, ***P < 0.0001). D Representative images of HCC cells after T cell-mediated killing assay. Cells were co-cultured with activated CD8+ T cells for 24 h. Activated T cells were washed away and the remaining cancer cells were photographed (n = 3), 100 µm. E Activated CD8+ T cells were harvested for RT-PCR assay to measure the IFN-γ and granzyme B expression. F The schematic diagram illustrates the utilization of DEN + CCL4 for chemical induction modeling. G Induced liver tissue specimens of Rbm30−/− mice exhibited reduced tumor size and PD-L1 content, whereas Rbm30KI/KI mice showed significantly accelerated tumor progression, 500/100 µm. H The liver weight of mice in different groups after modeling was calculated (n = 5, ***P < 0.0001). I FACS analysis of intratumor CD4+ and CD8+ T cells in induced liver tumors as shown in (D), the percentage of CD4+ T cells among the immune cell population was similar in the KO/KI and control tumors, the percentage of CD8+ T cells was significantly higher in Rbm30-KO tumors than WT tumors, and the proportion was significantly reduced in KI group (n = 5, ***P < 0.0001). J mIHC assays disclosed that the highly expressed RBM30 in HCC tumor tissues influenced the content of CD8+T cells (CD45+CD3+CD8+ cells) in the microenvironment.

Back to article page