Fig. 4: Yap drives basal-cell guided ECM remodeling and collective invasion independent of K14.
From: A YAP-centered mechanotransduction loop drives collective breast cancer cell invasion
a Confocal imaging of K14, K8, and Collagen I in control and Yap knockdown MMTV-PyMT organoids. Insets: K14-positive cells at the organoid-ECM interface. Representative image from three independent experiments. b Collagen I imaging using CNA35 GFP Collagen I dye in control and Yap knockdown organoids. c Collagen fiber order parameter near organoid rim (50 µm) with Yap shRNA1 or shRNA2 after 4 days of culture. Dotted line: average collagen order parameter within 50 µm from organoid rim on day 0 (mean = 0.16, SD = 0.08). Median (red line) n = 10 and n = 6 (shRNA1 -Dox and +Dox, respectively), n = 15 and n = 12 6 (shRNA2 -Dox and +Dox, respectively). b, c Data from 1 experiment. d, e Bead displacement towards MMTV-PyMT organoids with dox-inducible (d) Yap shRNA1 mixed organoid after 6 h in Collagen I and e YAP 5SA luminal organoids after 39h in Collagen I (−/+ Dox). Median (red line) from n = 63 (-dox) n = 60 (+Dox) (d) and n = 48 per condition (e) beads from one experiment. f Western blot analysis from two independent experiments showing K14, K17, K5 and actin expression from whole cell lysates of wild-type (WT) and K14 knockout (KO) MMTV-PyMT organoid cultures. g Confocal imaging of K14, p63 and K8 in WT and K14-KO organoids invading in Collagen I for 3 days. Arrowheads: WT and K14-KO leader cells with high nuclear Yap and low K8 signals. g Representative images from n = 8 organoids from 1 experiment. h, i WT and K14-KO (h) MMTV-PyMT organoids and i 4T1 spheroids invading Collagen I. Arrowheads: invasive strands. h, i Number and length of strand in WT and K14-KO organoids, medians (black line), 25/75 percentiles (boxes) and maximum/minimum values (whiskers) from (h) 72 (WT) and 84 (KO) invasive strands from five organoids per condition from one experiment and i 87 spheroids per condition from three independent experiments. P values, two-sided unpaired Mann–Whitney test. Scale bars: 50 μm (a, g), 100 μm (h, i), 10 μm (inset: a). Source data are provided as a Source Data file.
