Integrin-Linked Kinase: A Multi-functional Regulator Modulating Extracellular Pressure-Stimulated Cancer Cell Adhesion through Focal Adhesion Kinase and AKT

Cell adhesion is important in cancer metastasis. Malignant cells in cancer patients may be exposed to physical forces such as extracellular pressure and shear, that stimulate their adhesion to matrix proteins, endothelium and surgical wounds. Pressure induces phosphorylation of AKT and focal adhesion kinase (FAK), which are required for pressure-stimulated cancer cell adhesion, but what mediates this effect is unknown. ILK may influence cell adhesion and FAK and AKT phosphorylation in other settings. We therefore hypothesized that ILK might also regulate pressure-stimulated cancer cell adhesion through AKT and FAK phosphorylation. Silencing ILK by siRNA reduced basal cancer cell adhesion and prevented the stimulation of adhesion by pressure. ILK mediated pressure-stimulated adhesion through specifically regulating phosphorylation of AKT at Ser473 and FAK at Tyr397 and 576 as well as ILK association with FAK and AKT. The siRNA-mediated loss of function of ILK in regulating increase in adhesion by pressure was not rescued by overexpression of α-parvin, an important ILK binding partner, although pressure promoted ILK–α-parvin association and translocated both ILK and α-parvin from cytosol to membrane/cytoskeleton. ILK may be a key mediator of mechanotransduced signals in cancer cells and an important therapeutic target to inhibit metastatic cancer cell adhesion.

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T2003 Integrin-Linked Kinase: A Multi-Functional Regulator Modulating Extracellular Pressure-Stimulated Cancer Cell Adhesion Through Focal Adhesion Kinase and AKT

Gastroenterology ◽

10.1016/s0016-5085(09)62849-3 ◽

2009 ◽

Vol 136 (5) ◽

pp. A-618 ◽

Cited By ~ 1

Author(s):

Shouye Wang ◽

Marc D. Basson

Keyword(s):

Cell Adhesion ◽

Focal Adhesion Kinase ◽

Cancer Cell ◽

Focal Adhesion ◽

Cancer Cell Adhesion ◽

Integrin Linked Kinase ◽

Kinase A

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Akt directly regulates focal adhesion kinase through association and serine phosphorylation: implication for pressure-induced colon cancer metastasis

AJP Cell Physiology ◽

10.1152/ajpcell.00377.2010 ◽

2011 ◽

Vol 300 (3) ◽

pp. C657-C670 ◽

Cited By ~ 41

Author(s):

Shouye Wang ◽

Marc D. Basson

Keyword(s):

Colon Cancer ◽

Cell Adhesion ◽

Focal Adhesion Kinase ◽

Cancer Cells ◽

Cancer Cell ◽

Focal Adhesion ◽

Cancer Metastasis ◽

Serine Phosphorylation ◽

Colon Cancer Cells ◽

Cancer Cell Adhesion

Although focal adhesion kinase (FAK) is typically considered upstream of Akt, extracellular pressure stimulates cancer cell adhesion via Akt-dependent FAK activation. How Akt regulates FAK is unknown. We studied Akt-FAK interaction in colon cancer cells under 15 mmHg increased extracellular pressure. Pressure enhanced Akt-FAK association, blocked by inhibiting FAK or silencing Akt1 but not Akt2, and stimulated FAK serine phosphorylation in Caco-2 and human colon cancer cells from surgical specimens Akt1-dependently. FAK includes three serine (S517/601/695) and one threonine (T600)-containing consensus sequences for Akt phosphorylation. Studying S–>A nonphosphorylatable point mutants suggests that these sites coordinately upregulate FAK Y397 tyrosine phosphorylation, which conventionally initiates FAK activation, and mediate pressure-induced cancer cell adhesion. FAK(T600A) mutation did not prevent pressure-induced FAK(Y397) phosphorylation or adhesion. Akt1 appeared to directly bind FAK, and this binding did not depend on the FAK autophosphorylation site (Y397). In addition, our results demonstrated that Akt phosphorylated FAK at three novel serine phosphorylation sites, which were also not required for FAK-Akt binding. This novel interaction suggests that FAK and Akt may be dual kinase targets to prevent cancer cell adhesion and metastasis.

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Vimentin regulates lung cancer cell adhesion through a VAV2–Rac1 pathway to control focal adhesion kinase activity

Oncogene ◽

10.1038/onc.2014.123 ◽

2014 ◽

Vol 34 (15) ◽

pp. 1979-1990 ◽

Cited By ~ 82

Author(s):

L S Havel ◽

E R Kline ◽

A M Salgueiro ◽

A I Marcus

Keyword(s):

Lung Cancer ◽

Cell Adhesion ◽

Focal Adhesion Kinase ◽

Cancer Cell ◽

Focal Adhesion ◽

Kinase Activity ◽

Lung Cancer Cell ◽

Cancer Cell Adhesion ◽

Focal Adhesion Kinase Activity

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α-Actinin-1 phosphorylation modulates pressure-induced colon cancer cell adhesion through regulation of focal adhesion kinase-Src interaction

AJP Cell Physiology ◽

10.1152/ajpcell.00118.2007 ◽

2007 ◽

Vol 293 (6) ◽

pp. C1862-C1874 ◽

Cited By ~ 38

Author(s):

David H. Craig ◽

Beatrice Haimovich ◽

Marc D. Basson

Keyword(s):

Colon Cancer ◽

Cell Adhesion ◽

Focal Adhesion Kinase ◽

Tyrosine Phosphorylation ◽

Cancer Cell ◽

Focal Adhesion ◽

Cell Biology ◽

Adhesion Formation ◽

Colon Cancer Cell ◽

Cancer Cell Adhesion

Physical forces including pressure, strain, and shear can be converted into intracellular signals that regulate diverse aspects of cell biology. Exposure to increased extracellular pressure stimulates colon cancer cell adhesion by a β1-integrin-dependent mechanism that requires an intact cytoskeleton and activation of focal adhesion kinase (FAK) and Src. α-Actinin facilitates focal adhesion formation and physically links integrin-associated focal adhesion complexes with the cytoskeleton. We therefore hypothesized that α-actinin may be necessary for the mechanical response pathway that mediates pressure-stimulated cell adhesion. We reduced α-actinin-1 and α-actinin-4 expression with isoform-specific small interfering (si)RNA. Silencing of α-actinin-1, but not α-actinin-4, blocked pressure-stimulated cell adhesion in human SW620, HT-29, and Caco-2 colon cancer cell lines. Cell exposure to increased extracellular pressure stimulated α-actinin-1 tyrosine phosphorylation and α-actinin-1 interaction with FAK and/or Src, and enhanced FAK phosphorylation at residues Y397 and Y576. The requirement for α-actinin-1 phosphorylation in the pressure response was investigated by expressing the α-actinin-1 tyrosine phosphorylation mutant Y12F in the colon cancer cells. Expression of Y12F blocked pressure-mediated adhesion and inhibited the pressure-induced association of α-actinin-1 with FAK and Src, as well as FAK activation. Furthermore, siRNA-mediated reduction of α-actinin-1 eliminated the pressure-induced association of α-actinin-1 and Src with β1-integrin receptor, as well as FAK-Src complex formation. These results suggest that α-actinin-1 phosphorylation at Y12 plays a crucial role in pressure-activated cell adhesion and mechanotransduction by facilitating Src recruitment to β1-integrin, and consequently the association of FAK with Src, to enhance FAK phosphorylation.

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