Journal: bioRxiv
Article Title: Integrin-TGFβ axis induces partial EMT in basal-like cells to lead collective invasion
doi: 10.1101/2025.04.04.647177
Figure Lengend Snippet: (A) DNA sequence of the Itgα2 gene to confirm gene knockout by Crispr-Cas9 gene editing. Red regions indicate the insertion of one base pair compared to the wildtype Itgα2 sequence. (B) Western blot analysis showing Itgα2 and GAPDH expression from whole cell lysates of MMTV-PyMT organoids WT or KO (gRNA1 or gRNA2). (C) Confocal imaging of Itgα2 and K8 in MMTV-PyMT organoids with Itgα2 WT or knockout (KO) grown in Collagen I for 3 days. White arrowheads: invading strands in Itgα2 WT organoids led by basal-like cells (low K8, high Itgα2, insets), White arrows: non-invading basal-like cells at the ECM interface in Itgα2 KO organoids (low K8, low Itgα2, insets). (D) Percentage of invasive organoids in MMTV-PyMT organoids Itgα2-WT versus Itgα2-KO (gRNA2). (E) Mean gray value of Col ¾ relative to Collagen I reflection in MMTV-PyMT organoids with Itgα2-WT and Itgα2-KO. Median: red lines, from n = 11 organoids per group from two independent experiments. (F) Single confocal slice showing INHBA and K8 expression in Itgα2-WT and Itgα2-KO MMTV-PyMT organoids cultured in 3D Collagen I for three days. Insets show basal-like cells (K8 low) guiding invasive strands (Itgα2-WT) or remaining at the organoid rim (Itgα2 KO, non-invasive). (G) Mean-gray value of Inhba in basal-like cells (K8-low) located at the rim of Itgα2 WT vs. KO MMTV-PyMT organoids (3D Collagen I, day 1). Median: red lines, n =11 cells from 6 Itgα2-WT organoids, and n = 12 cells from 7 Itgα2-KO organoids from one experiment. (H) qPCR analysis showing relative mRNA expression of CTGF in MMTV-PyMT Itgα2-KO organoids compared to Itgα2-WT organoids treated with Activin A ligand (20 ng/μl) or vehicle control (0.1% BSA) for three days. Bar graph represents mean normalized expression values (relative to housekeeping genes) ± SD from four independent experiments. (I) Kaplan-Meier plot correlating ITGB1 gene expression with DMFS in grade 3 breast cancer patients. Scale bars: 50 μm (C, F), 25 μm (C, F, Zoom in). P values, two-sided unpaired Mann–Whitney test (E, G), two-sided Kruskal-Wallis test (Dunn’s multiple comparison) (H), Logrank test (I).
Article Snippet: The following antibodies were used: rabbit anti-human Vimentin (Cat#ab92547, Abcam), chicken anti-human Vimentin (Cat#PA1-16759, Invitrogen) rabbit anti-human Keratin 14 (Cat# 905301, Biolegend), rat anti-mouse Keratin 8 (Cat# 531826, DSHB), rabbit anti-rat Collagen I cleavage site (Col ¾, Cat#0217-025, immunoGlobe), rabbit anti-human integrin α2 (Cat#ab181548, Abcam), rabbit anti-human Inhba (Cat#10651-1-AP, Proteintech), Mouse IgG1 isotype control (MAB002, R&D Systems), anti-Activin A antibody (Cat#AF338, R&D Systems).
Techniques: Sequencing, Gene Knockout, CRISPR, Western Blot, Expressing, Imaging, Knock-Out, Cell Culture, Control, Gene Expression, MANN-WHITNEY, Comparison