TY - JOUR

T1 - A critical role of integrin-linked kinase, ch-TOG and TACC3 in centrosome clustering in cancer cells

AU - Fielding, Andrew B.

AU - Lim, S

AU - Montgomery, K

AU - Dobreva, I

AU - Dedhar, S

PY - 2011/2/3

Y1 - 2011/2/3

N2 - Many cancer cells contain more than two centrosomes, which imposes a potential for multipolar mitoses, leading to cell death. To circumvent this, cancer cells develop mechanisms to cluster supernumerary centrosomes to form bipolar spindles, enabling successful mitosis. Disruption of centrosome clustering thus provides a selective means of killing supernumerary centrosome-harboring cancer cells. Although the mechanisms of centrosome clustering are poorly understood, recent genetic analyses have identified requirements for both actin and tubulin regulating proteins. In this study, we demonstrate that the integrin-linked kinase (ILK), a protein critically involved in actin and mitotic microtubule organization, is required for centrosome clustering. Inhibition of ILK expression or activity inhibits centrosome clustering in several breast and prostate cancer cell lines that have centrosome amplification. Furthermore, cancer cells with supernumerary centrosomes are significantly more sensitive to ILK inhibition than cells with two centrosomes, demonstrating that inhibiting ILK offers a selective means of targeting cancer cells. Live cell analysis shows ILK perturbation leads cancer cells to undergo multipolar anaphases, mitotic arrest and cell death in mitosis. We also show that ILK performs its centrosome clustering activity in a focal adhesion-independent, but centrosome-dependent, manner through the microtubule regulating proteins TACC3 and ch-TOG. In addition, we identify a specific TACC3 phosphorylation site that is required for centrosome clustering and demonstrate that ILK regulates this phosphorylation in an Aurora-A-dependent manner.

AB - Many cancer cells contain more than two centrosomes, which imposes a potential for multipolar mitoses, leading to cell death. To circumvent this, cancer cells develop mechanisms to cluster supernumerary centrosomes to form bipolar spindles, enabling successful mitosis. Disruption of centrosome clustering thus provides a selective means of killing supernumerary centrosome-harboring cancer cells. Although the mechanisms of centrosome clustering are poorly understood, recent genetic analyses have identified requirements for both actin and tubulin regulating proteins. In this study, we demonstrate that the integrin-linked kinase (ILK), a protein critically involved in actin and mitotic microtubule organization, is required for centrosome clustering. Inhibition of ILK expression or activity inhibits centrosome clustering in several breast and prostate cancer cell lines that have centrosome amplification. Furthermore, cancer cells with supernumerary centrosomes are significantly more sensitive to ILK inhibition than cells with two centrosomes, demonstrating that inhibiting ILK offers a selective means of targeting cancer cells. Live cell analysis shows ILK perturbation leads cancer cells to undergo multipolar anaphases, mitotic arrest and cell death in mitosis. We also show that ILK performs its centrosome clustering activity in a focal adhesion-independent, but centrosome-dependent, manner through the microtubule regulating proteins TACC3 and ch-TOG. In addition, we identify a specific TACC3 phosphorylation site that is required for centrosome clustering and demonstrate that ILK regulates this phosphorylation in an Aurora-A-dependent manner.

KW - Aurora Kinases

KW - Azo Compounds

KW - Breast Neoplasms

KW - Cell Line

KW - Cell Line, Tumor

KW - Centrosome

KW - Cytokinesis

KW - Female

KW - Fluorescent Antibody Technique

KW - Humans

KW - Male

KW - Microscopy, Fluorescence

KW - Microtubule-Associated Proteins

KW - Phosphorylation

KW - Prostatic Neoplasms

KW - Protein Binding

KW - Protein-Serine-Threonine Kinases

KW - Pyrazoles

KW - RNA Interference

KW - Spindle Apparatus

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1038/onc.2010.431

DO - 10.1038/onc.2010.431

M3 - Journal article

C2 - 20838383

VL - 30

SP - 521

EP - 534

JO - Oncogene

JF - Oncogene

SN - 0950-9232

IS - 5

ER -