Journal: bioRxiv

Article Title: Sec23b regulates cell migration by orchestrating collagen I secretion and processing

doi: 10.64898/2026.03.04.709595

Figure Lengend Snippet: A. Velocity of GPI vesicles in MDA-MB-231 cells expressing control scrambled shRNA (n = 14), or Sec23b KD1 (n = 9) or KD2 (n = 14) shRNAs. One-way ANOVA with Dunnett’s multiple comparisons test. Means ± standard deviation. B. Representative western blot of concentrated media from MDA-MB-231 cells expressing control scrambled shRNA or Sec23b KD1 or KD2 shRNAs blotted with anti-bodies against procollagen I or anti-His epitope tag. C. Normalized ratios of procollagen I to recombinant His-tagged MRCKβ control protein in conditioned media from MDA-MB-231 cells expressing control scrambled shRNA, or Sec23b KD1 or KD2 shRNAs (n = 4). One-way ANOVA with Dunnett’s multiple comparisons test. Means ± standard deviation. D. Immunoflourescence images of MDA-MB-231 cells, expressing control scrambled shRNA, or Sec23b KD1 or KD2 shRNAs, stained for F-Actin with Cy3-labelled fluorescent phalloidin or anti-telocollagen I antibody. E. Normalized ratios of telocollagen I fluorescence to Cy3-phalloidin fluorescence intensity for MDA-MB-231 cells expressing control scrambled shRNA (n = 48), or Sec23b KD1 (n = 45) or KD2 (n = 42) shRNAs. One-way ANOVA with Dunnett’s multiple comparisons test. Means ± standard deviation. F. Random migration velocities for MDA-MB-231 cells expressing control scrambled shRNA (n = 14), or Sec23b KD1 (n = 9) or KD2 (n = 14) shRNAs. One-way ANOVA with Dunnett’s multiple comparisons test. Means ± standard deviation. G. Frequency of Sec23b gene amplification in invasive breast cancers from 1589 patients using cBioPortal to query the METABRIC database of somatic copy number aberrations. H. Probability of relapse-free survival of 1962 patients divided at the median expression level into high and low expressing cohorts. Logrank test p value shown.

Article Snippet: The following antibodies were used: rabbit anti-Sec23b (Abcam; 1:1000); mouse anti-FLAG (Sigma-Aldrich; 1:1000); mouse anti-vimentin (Sigma-Aldrich; 1:2000); anti-GAPDH (DHSB; 1:2500); anti-procollagen clone SP1.D8 (DHSB; 1:200); rabbit anti-His (Cell Signaling Tech; 1:1000); secondary antibodies conjugated to IRDye 680 or 800 (LI-COR).

Techniques: Expressing, Control, shRNA, Standard Deviation, Western Blot, Recombinant, Staining, Fluorescence, Migration, Amplification