Fig. 1

hY4 RNA fragments are selectively sorted into lung cancer cell-derived EVs and inhibit cancer cell progression. A The level of hY4F RNA in plasma from healthy control subjects (CTRL, n = 34) and non-small cell lung cancer patients (NSCLC, n = 49) was assessed by qPCR. B The level of hY4F in EVs and cells from normal lung fibroblast (IMR-90) and lung cancer cells (A549, H460, H1975 and H2030) was examined by qPCR. C The hY4F level in EVs and cell lysates from hY4F mimic/NC-transfected A549 cells was measured by qPCR (at 48 h after transfection). The effect of a hY4F mimic on A549 cell proliferation was examined by (D) CCK-8 (at 24, 48, and 72 h after transfection) and (E) EdU assays (at 48 h after transfection). F Flow cytometry using Annexin V-FITC/PI staining was performed to examine apoptosis of hY4F-overexpressing A549 cells (at 24 h after transfection). G Cell cycle analysis by PI staining-based flow cytometry with hY4F mimic/NC-transfected A549 cells (at 24 h after transfection). H Colony formation assay with A549 cells at 7 d after transfected with hY4F mimic/NC. The effect of a hY4F mimic on A549 (I) migration and (J) invasion was assessed by transwell assay (at 24 h after transfection). Data from three independent experiments are shown as the mean ± SD (error bars). *P < 0.05, **P < 0.01, ***P < 0.001 (Student’s t-test). NC: negative control