Fig 5. MYH9 knockdown and neratinib treatment inhibit colony formation on Matrigel and proliferation in HER2+ breast cancer cells.

(A) BT474 and MDA-MB-453 cells transduced with MYH9 shRNA were seeded on a basement membrane of matrigel at a density of 2 × 10⁴ cells/well. Cells treated with vehicle (DMSO), doxycycline (500 nM)/48 h, neratinib (200 nM) once, and combination. Phase contrast images of acini for all cell lines were captured at 10× magnification and the average size of each cellular structure was quantified and expressed as mean of areas ± SEM, n = 5 random fields * p <0.05 for indicated comparison (B). (C) BT474 and MDA-MB-453 cells transduced with a doxycycline inducible shRNA targeting MYH9 were treated with doxycycline (500 nM) and neratinib (200 nM) for 72 hr. After 72 hr, the media containing the drug was replaced with 5 mg/mL MTT dissolved in cell line specific media and incubated for 4 hr. After 4 hr the media was aspirated, and crystals were dissolved with isopropanol. The bar graphs are represented as mean; Error bars: SEM, n = 3 * p <0.05 for indicated comparison.