Ab134914

Cells were fixed at either (1) room temperature for 10 min using 4% paraformaldehyde (PFA) for Figs. 1 and 2 or (2) room temperature for 20 min using 1.6% PFA for Fig. 6 and Extended Data Figs. 5 and 6. Fixed cells were permeabilized and blocked for 1 h using blocking buffer (5% BSA, 0.1% Triton X-100) and incubated overnight at 4 °C with primary antibody: anti-αSMA (1:100, Abcam, ab7817), anti-periostin (1:50, R&D Systems, AF2966), anti-FLAG (1:100, Sigma-Aldrich, B3111), anti-H1.0 (1:100, Abcam, ab134914), anti-vimentin (1:200, Abcam, ab45939) or anti-lamin A/C (1:200, Abcam, ab8984). Appropriate concentration of secondary antibodies was incubated at room temperature for 1 h. Imaging was performed on a fluorescence microscope (Zeiss Axio Vert.A1) or a confocal microscope (Nikon, A1R, ×60). Nuclei were stained using DAPI. Secondary antibody staining alone was used as a negative control.

Preparation of protein lysates and Western blot were performed using standard procedures. Proteins from conditioned medium were precipitated by addition of trichloroacetic (10% v/v), pelleted by centrifugation at 20,000 g for 15 min at 4°C, washed twice with ice‐cold acetone, air‐dried, and resuspended in 25 μl 2× Laemmli buffer.
Antibodies against INHBA (sc166503, Santa Cruz, 1:500 diluted), mDia2 (recognizing both mDia2 and DIAPH3; 1:5,000 diluted) (Isogai et al, 2015a,b), αSMA (A2547, Sigma‐Aldrich, 1:500 diluted), p53 (sc‐126, Santa Cruz or AB17990, Abcam, 1:500 diluted), MYC‐tag (AB9106, Abcam, 1:1,000 diluted), α‐tubulin (T5168, Sigma‐Aldrich. 1:10,000 diluted), vinculin (V4505, Sigma‐Aldrich, 1:2,000 diluted), histone H1 (AB134914, Abcam, 1:500 diluted), and GAPDH (#5G4, HyTest, 1:10,000 diluted) were used. Secondary antibody was anti‐rabbit or anti‐mouse IgG (W4011 and W4021, Promega, 1:8,000 diluted) conjugated with horseradish peroxidase, and chemiluminescence was determined using the WesternBright ECL Detection System (Advansta). Bands were visualized using Fusion Solo 6S (Witeg AG), and intensity was quantified with ImageJ software (National Institutes of Health).