European Journal of Cell Biology 87 (2008) 377–387 HSP27 regulates cell adhesion and invasion via modulation of focal adhesion kinase and MMP-2 expression Joong-Won Lee a , Hee-Jin Kwak a , Je-Jung Lee a , Yong-Nyun Kim b , Jung Weon Lee c , Myung-Jin Park a , Seung Eun Jung d,e , Seok-Il Hong a , Jeong-Hwa Lee d,Ã , Jae-Seon Lee a,Ã a Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, Korea b Division of Specific Organs Center, National Cancer Center, Gyeonggi-Do 411-769, Korea c Cancer Research Institute, College of Medicine, Seoul National University, Seoul 110-799, Korea d Department of Biochemistry, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea e Department of Medical Science, College of Medicine, The Yonsei University, Seoul 120-752, Korea Received 22 October 2007; received in revised form 21 March 2008; accepted 22 March 2008 Abstract Heat-shock protein 27 (HSP27), a member of the small heat-shock protein family, is a molecule involved in cellular protection in response to a variety of stresses such as heat shock, toxicants, and oxidative stress. HSP27 is also known to modulate cell functions via interaction with the actin cytoskeleton. To elucidate the functions of HSP27 in adhesion and invasion in more detail, we examined NIH3T3 cells overexpressing HSP27. HSP27 overexpression affected FAK phosphorylation and focal adhesion formation, depending on integrin-mediated actin cytoskeleton polymerization. In addition, the HSP27-overexpressing cells showed a retarded cell migration and invasion in wound-healing assays. Such HSP27-mediated retarded wound healing was correlated with reduced matrix metalloproteinase-2 (MMP-2) expression. The transcription factor for MMP-2 expression, signal transducer and activator or transcription 3 (STAT3), was correspondingly less phosphorylated. When a phosphomimetic form of HSP27 was transiently transfected, migration and invasion were similarly decreased via the regulation of the FAK/STAT3/MMP-2 signaling pathway, whereas a non-phosphorylatable form of HSP27 blocked HSP27-mediated phenotypes probably due to a dominant-negative effect on phosphorylation of endogenous HSP27. Altogether, our results suggest that HSP27 can enhance cell adhesion and modulate cell migration and invasion via the coordination of FAK-dependent actin organization and STAT3-dependent MMP-2 expression, and that phosphorylation of HSP27 is indispensable to regulate this signal pathway. r 2008 Elsevier GmbH. All rights reserved. Keywords: HSP27; FAK; MMP-2; Migration; Invasion Introduction Heat-shock protein 27 (HSP27) is a member of the small heat-shock protein family, and shares homology with the aB-crystallins, major proteins of the eye lens fiber cells. HSP27 is constitutively expressed in a variety ARTICLE IN PRESS www.elsevier.de/ejcb 0171-9335/$ - see front matter r 2008 Elsevier GmbH. All rights reserved. doi:10.1016/j.ejcb.2008.03.006 Ã Corresponding authors. Tel.: +82 2590 1180; fax: +82 2596 4435 (Jeong-Hwa Lee); Tel./fax: +82 2970 1388; (Jae-Seon Lee). E-mail addresses: leejh@catholic.ac.kr (J.-H. Lee), jaeslee@kcch.re.kr (J.-S. Lee).