Fig. 6

Cells restrained retraction fiber & migrasome (R&M) formation cannot alleviate ER stress. A Cell growth rate of ITGA5- or TSPAN4-depleted U87MG cells in CQ (50 μM) or AS (10 μM)-treated conditions. Relative cell growth was calculated based on cell confluence mask analyzed by using IncuCyte ZOOM. B Annexin V/PI staining for analyzing cell death of ITGA5- or TSPAN4-depleted U87MG cells in CQ- or AS-treated conditions. Cells were harvested after 72-h treatment of CQ or AS. *Indicates p < 0.05; ***indicates p < 0.001. Data are expressed as mean ± SEM. Student’s t-test was used to analyze the statistical significance between each population (n = 3 for technical replicates). C qRT-PCR data for evaluating mRNA levels of spliced XBP1. *Indicates p < 0.05. **Indicates p < 0.01. ***Indicates p < 0.001. Data are expressed as mean ± SEM. Student’s t-test was used to analyze the statistical significance between each group (n = 3). D Graphical summary of study. In ITGA5- or TSPAN4-depleted condition, cells have a decreased number of R&Ms and lower capability to relieve ER stress, resulting in increased apoptosis