Bousgouni Vicky, Inge Oliver, Robertson David, Jones Ian, Clatworthy Innes, Bakal Chris
Division of Cancer Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
iScience. 2022 Aug 8;25(8):104795. doi: 10.1016/j.isci.2022.104795. eCollection 2022 Aug 19.
Rho GTP Exchange Factors (RhoGEFs) and Rho GTPase Activating Proteins (RhoGAPs) are large families of molecules that regulate shape determination in all eukaryotes. In pathologies such as melanoma, RhoGEF and RhoGAP activity underpins the ability of cells to invade tissues of varying elasticity. To identify RhoGEFs and RhoGAPs that regulate melanoma cell shape on soft and/or stiff materials, we performed genetic screens, in tandem with single-cell quantitative morphological analysis. We show that ARHGEF9/Collybistin (Cb) is essential for cell shape determination on both soft and stiff materials, and in cells embedded in 3D soft hydrogel. ARHGEF9 is required for melanoma cells to invade 3D matrices. Depletion of ARHGEF9 results in loss of tension at focal adhesions decreased cell-wide contractility, and the inability to stabilize protrusions. Taken together we show that ARHGEF9 promotes the formation of actin-rich filopodia, which serves to establish and stabilize adhesions and determine melanoma cell shape.
Rho鸟嘌呤核苷酸交换因子（RhoGEFs）和Rho鸟嘌呤核苷酸酶激活蛋白（RhoGAPs）是在所有真核生物中调节形态决定的大分子家族。在诸如黑色素瘤等病症中，RhoGEF和RhoGAP活性是细胞侵入不同弹性组织能力的基础。为了鉴定在柔软和/或坚硬材料上调节黑色素瘤细胞形态的RhoGEF和RhoGAP，我们进行了遗传筛选，并结合单细胞定量形态分析。我们发现，ARHGEF9/结肠双调蛋白（Cb）对于在柔软和坚硬材料上以及嵌入三维软质水凝胶中的细胞的形态决定至关重要。ARHGEF9是黑色素瘤细胞侵入三维基质所必需的。ARHGEF9的缺失导致粘着斑处张力丧失，全细胞收缩性降低，以及无法稳定突起。综合来看，我们发现ARHGEF9促进富含肌动蛋白的丝状伪足的形成，这有助于建立和稳定粘附并决定黑色素瘤细胞的形态。
