Integrin-linked kinase tunes cell-cell and cell-matrix adhesions to regulate the switch between apoptosis and EMT downstream of TGFβ1.

TitleIntegrin-linked kinase tunes cell-cell and cell-matrix adhesions to regulate the switch between apoptosis and EMT downstream of TGFβ1.
Publication TypeJournal Article
Year of Publication2021
AuthorsKilinc, ANihan, Han, S, Barrett, LA, Anandasivam, N, Nelson, CM
JournalMol Biol Cell
Volume32
Issue5
Pagination402-412
Date Published2021 03 01
ISSN1939-4586
Abstract

<p>Epithelial-mesenchymal transition (EMT) is a morphogenetic process that endows epithelial cells with migratory and invasive potential. Mechanical and chemical signals from the tumor microenvironment can activate the EMT program, thereby permitting cancer cells to invade the surrounding stroma and disseminate to distant organs. Transforming growth factor β1 (TGFβ1) is a potent inducer of EMT that can also induce apoptosis depending on the microenvironmental context. In particular, stiff microenvironments promote EMT while softer ones promote apoptosis. Here, we investigated the molecular signaling downstream of matrix stiffness that regulates the phenotypic switch in response to TGFβ1 and uncovered a critical role for integrin-linked kinase (ILK). Specifically, depleting ILK from mammary epithelial cells precludes their ability to sense the stiffness of their microenvironment. In response to treatment with TGFβ1, ILK-depleted cells undergo apoptosis on both soft and stiff substrata. We found that knockdown of ILK decreases focal adhesions and increases cell-cell adhesions, thus shifting the balance from cell-matrix to cell-cell adhesion. High cell-matrix adhesion promotes EMT whereas high cell-cell adhesion promotes apoptosis downstream of TGFβ1. These results highlight an important role for ILK in controlling cell phenotype by regulating adhesive connections to the local microenvironment.</p>

DOI10.1091/mbc.E20-02-0092
Alternate JournalMol Biol Cell
PubMed ID33405954
PubMed Central IDPMC8098849
Grant ListR01 CA187692 / CA / NCI NIH HHS / United States
U01 CA214292 / CA / NCI NIH HHS / United States
/ HHMI / Howard Hughes Medical Institute / United States