Skip to main content
. 2020 May 26;8(1):e000294. doi: 10.1136/jitc-2019-000294

Figure 1.

Figure 1

PD-L1 is downregulated in the majority of human lung cancers and mouse lung cancers, and mouse lung cancers induced by urethane are largely resistant to PD-1 blockade therapy. (A) TCGA data showing PD-L1 downregulation in human lung cancer. Left: gray dots and red dots stand for normal lung (NL) tissues and lung tumor (T) tissues, respectively. Right: PD-L1 expression profile in lung cancer tissues. Sample numbers are indicated. (B) EMBL-EBI data showing PD-L1 downregulation in human lung cancer cell lines. (C) Quantitative RT-PCR (qPCR) analysis showing PD-L1 downregulation in human lung cancer. Matched normal lung tissues from the same patients were used as controls. (D) IHC assay showing PD-L1 downregulation in human lung cancer. Scale bar, 20 µm. (E) qPCR and FACS analysis showing PD-L1 downregulation in most human lung cancer cell lines (n=3). NL-20 is a normal human lung epithelial cell line; others are human lung cancer cell lines. (F) qPCR analysis showing PD-L1 downregulation in mouse lung cancer cell lines. (G, H) qPCR (G) and FACS (H) analysis showing PD-L1 downregulation in mouse primary lung cancers induced by urethane. (I) Urethane model showing large resistance of lung cancer to PD-1 blockade therapy. FACS, fluorescent activated cell sorting; MFI, mean fluorescence intensity; *p<0.05; **p<0.01; ns, not significant; PD-1, programmed cell death 1; PD-L1, programmed death ligand 1; RSEM, RNA-Seq by Expectation Maximization; TCGA, The Cancer Genome Atlas.