Figure 2. ETV4 knockdown reduces tumor cell proliferation, tumor invasion, and growth.

(A) GFP expression in GIST882 cells after transduction with either ETV4 or control shRNA lentiviral constructs and growth under continuous puromycin selection. (B) ETV4 and ETV1 mRNA expression measured by real-time PCR. (C) Cell viability of GIST882 cells after ETV4 knockdown. (D) Matrigel invasion assay of GIST882 cells after ETV4 knockdown. Scale bar, 100 μm. (E) 1x10⁵ GIST882 cells stably transduced with ETV4 or control shRNA were injected into the flanks of NSG mice and tumors were harvested 4 months later. Representative gross pictures and tumor weights are shown. n = 8 mice per group. Scale bar, 1 cm. (F) Ki-67 staining in ETV4 knockdown or control tumors. Scale bar, 20 μm. (G) Cell viability of murine S2 cells after stable ETV4 knockdown by shRNA infection. (H) Matrigel invasion assay of murine S2 cells after ETV4 knockdown. (I) Weights of flank tumors in NSG mice 4 months after inoculation with 1x10⁵ S2 cells transduced with ETV4 or control shRNA (n = 4 mice per group). (J) Representative Ki-67 staining in ETV4 knockdown or control S2 tumors. Scale bar, 20 μm. Lines represent the median. All bars, mean ± SEM, Student’s t test; ^*P < 0.05, ^***P < 0.001.