Fig. 4

Endoplasmic reticulum (ER)-associated proteins are abundant cargo proteins present in retraction fiber & migrasome (R&M). A Heatmap represents highly enriched ER-associated proteins in R&M portion. Relative abundance values of both extracellular vesicle (EV) and R&M samples were standardized to z-score. B Live-cell imaging of U87MG cells for visualizing ER by using ER-Tracker Red. White, EGFP-CD9. Red, ER-Tracker. Scale bars, 20 μm. C Western blotting of SQSTM1, LC3B, RPL4, RPS13, p-eIF2α (Ser51), and β-actin proteins after treatment of chloroquine (CQ; 50 μM, 12 h) or NaAsO₂ (AS; 10 μM, 12 h) in LN229 cells. W(M), molecular weight. D Live-cell imaging for quantifying R&M formation in CQ (50 μM, 12 h) or AS (10 μM, 12 h) treatment condition. Green, EGFP-CD9. White, tdTomato-RPS13. Scale bars, 20 μm. E Quantification of average migrasome area (μm²) in data from (D). LN229 cell was used for observation and image analyses. *Indicates p < 0.05; **indicates p < 0.01; ***indicates p < 0.001. Data are expressed as mean ± SEM. The unpaired nonparametric Mann–Whitney U-test was used to analyze the statistical significance between each group (n = 35). F Quantification of total migrasome number and total RF length (× 10² μm) in data from (D)