Skip to main content
. 2023 Jan 17;133(2):e153470. doi: 10.1172/JCI153470

Figure 2. CD47 is required for a KRAS-driven antiphagocytic effect in lung cancer.

Figure 2

(A) Differential expression of CD47 in patients with lung adenocarcinoma with different KRAS mutation statuses. Cancer cells were isolated from 12 patients with KRASWT and 6 patients with KRASMUT and analyzed for CD47 expression by FACS. Representative FACS results and quantification of all patients are shown. Max, maximum. (B and C) KrasLSL-G12D/+ p53fl/fl mice showed a gradual increase in CD47 expression in lung tumor tissues over time. KrasLSL-G12D/+ p53fl/fl mice were sacrificed at 0, 1, 2, and 3 months, respectively, and analyzed for CD47 expression by IHC (B) and immunoblotting (C). Scale bar: 20 μm. (D) Immunoblot analysis of CD47 expression in Ras-less MEFs overexpressing various KRAS mutations (WT, G12C, or G12D). (E and F) Effect of KRAS manipulation on CD47 expression in H358 and SK-LU-1 cells. Cells were transfected with plasmids expressing KRASWT, KRASG12C, or KRASG12D or with 3 KRAS siRNAs. After 48 hours, CD47 expression was determined by immunoblotting. (G–L) Effect of Cd47 knockdown on Kras-driven tumorigenesis and macrophage phagocytosis in vivo. KrasLSL-G12D/+ p53fl/fl mice were intratracheally administered adeno-Cre along with an AAV encoding the shRNA of Cd47 (AAV-Cd47 shRNA) or a scrambled negative control shRNA (AAV-control shRNA). (G) Kaplan-Meier survival analysis. (H) Representative micro-CT visualization of tumors 3 months after administration. (I) Representative H&E staining of lung sections. Scale bar: 2 mm. (J) Representative IHC staining for CD47. Scale bar: 20 μm. (K) Representative immunoblot of CD47 expression in lung tumors. (L) Immunofluorescence staining for CD11b (red), iNOS (purple), and KRASG12D (green) in lung tumors showing an increase in macrophage phagocytosis of tumor cells with Cd47 shRNA. Representative images and quantification results (n = 5 mice) are shown. Arrows indicate KRASG12D+iNOS+CD11b+ cells. Scale bar: 50 μm. Original magnification, ×40 (enlarged insets). Data are shown as the mean ± SEM. ***P < 0.001 and ****P < 0.0001, by unpaired t test (A and L) or log-rank (Mantel-Cox) test (G).