Fig. 1: Knockdown of TM9SF4 increases the cell size and promotes F-actin formation in cancer cells.

a, b Endogenous expression level of TM9SF4 in different cell types (a) and knockdown efficiency of TM9SF4-shRNAs (b). Shown are representative immunoblot images (left) and summary data (right) of TM9SF4 protein level (n = 3 biologically independent experiments). c–e TM9SF4 knockdown by lenti-shRNAs increased the cell size and F-actin stress fiber formation in A2780 cells, MCF-7 cells and T47D cells, but not in NIH3T3 cells and MCF-10A cells. Shown are representative confocal microscope images after FITC-phalloidin staining (c) and summary data (d, e). In e, the percentage of cells containing thick actin stress fiber with a diameter >0.5 μm was analyzed (n = 4 biologically independent experiments, >200 cells from three different fields per experiment). Scale bar = 10 μm. f, g TM9SF4 knockdown increased the formation of actin spikes and multipolar morphology in A2780 cells. Shown are representative cell images after FITC-phalloidin staining (f) and summary data (g) (n = 7 biologically independent experiments). Scale bar = 10 μm. h, i TM9SF4 knockdown increased the F-actin as in pellet (P) while reduced the G-actin as in supernatant (S) in A2780 cells. Shown are representative immunoblot images (h) and summary data (i). ERK, cytosolic marker; β-tubulin, cytoskeleton marker (n = 3 biologically independent experiments). Data are presented as mean ± SEM and two-tailed unpaired Student’s t-test was used for statistical analysis (a, b, d, e, g, i). NS, no significant difference. Source data are provided as a Source Data file.