Overexpression of LASP-1 mediates migration and proliferation of human ovarian cancer cells and influences zyxin localisation

Abstract

LIM and SH3 protein 1 (LASP-1), initially identified from human breast cancer, is a specific focal adhesion protein involved in cell proliferation and migration. In the present work, we analysed the effect of LASP-1 on biology and function of human ovarian cancer cell line SKOV-3 using small interfering RNA technique (siRNA).Transfection with LASP-1-specific siRNA resulted in a reduced protein level of LASP-1 in SKOV-3 cells. The siRNA-treated cells were arrested in G 2 /M phase of the cell cycle and proliferation of the tumour cells was suppressed by 60 -90% corresponding to around 70% of the cells being transfected successfully as seen by immunofluorescence. Moreover, transfected tumour cells showed a 40% reduced migration. LASP-1 silencing is accompanied by a reduced binding of the LASP-1-binding partner zyxin to focal contacts without changes in actin stress fibre and microtubule organisation or focal adhesion morphology as observed by immunofluorescence. In contrast, silencing of zyxin is not influencing cell migration and had neither influence on LASP-1 expression nor actin cytoskeleton and focal contact morphology suggesting that LASP-1 is necessary and sufficient for recruiting zyxin to focal contacts.The data provide evidence for an essential role of LASP-1 in tumour cell growth and migration, possibly through influencing zyxin localization.

Global Gene Expression Analysis Identifies PDEF Transcriptional Networks Regulating Cell Migration during Cancer Progression

“…In a morphologically heterogeneous population of cells that do not express PDEF, invasive breast cancer cells display a similar defined localization of LASP1 at the leading lamellipodia and at the trailing edge ( Figure 4A, top) and in the cytoplasmic region. Furthermore, LASP1 is colocalized with the focal adhesion protein zyxin ( Figure 4A, top), as reported previously (Li et al, 2004;Grunewald et al, 2006Grunewald et al, , 2007b. However, upon inducible expression of PDEF, LASP1 immunofluorescence is observed at multiple sites around the cell periphery and not defined to a single lamellipodia, although cytoplasmic LASP1 remains unchanged and LASP1-zyxin colocalization is still observed (Figure 4A, bottom).…”

STEAP1 Is Associated with the Invasive and Oxidative Stress Phenotype of Ewing Tumors

“…See Supplementary Methods. Two-dimensional gel electrophoresis and mass spectrometry Two-dimensional (2D) isoelectric focusing/SDS-PAGE were essentially carried out as described previously (23). For spot selection and mass spectrometry, see Supplementary Methods.…”

Nuclear localisation of LASP-1 correlates with poor long-term survival in female breast cancer

“…LIM and SH3 protein 1 mRNA is expressed ubiquitously at low basal levels in all normal human tissues, but is overexpressed in metastatic human breast cancer (Grunewald and Butt, 2008) and ovarian cancer (Grunewald et al, 2007b;Dimova et al, 2009). In a recent case -control study, LASP-1-expression correlated significantly with tumour size and nodal-positivity (Grunewald et al, 2007a).…”

“…LASP-1 is localised within multiple sites of dynamic F-actin assembly such as focal contacts, lamellipodia and membrane ruffles it binds to the specific shuttle proteins Zyxin and lipoma preferred partner (LPP) and is involved in cell migration and proliferation (Schreiber et al, 1998;Chew et al, 2002;Butt et al, 2003;Nakagawa et al, 2006). Silencing of LASP-1 by RNA-interference in various cancer cell lines resulted in strong inhibition of proliferation and migration with cell cycle arrest in G2/M-phase (Grunewald et al, 2006(Grunewald et al, , 2007b.…”