The actin cytoskeleton is a dynamic structure within cells. It responds to a variety of extra- and intracellular signals that direct vital processes such as cell division, differentiation and movement. Our laboratory is interested in how the actin cytoskeleton operates to enhance tumour cell invasion and metastasis.
We study how the ADF (actin depolymerizing factor)/ cofilin family of proteins might alter the actin cytoskeleton in tumour cell behaviour. ADF/cofilin proteins bind actin and are involved in the turnover of actin filaments at the leading edge of migrating cells. We have shown that brain tumour (glioblastoma) cells move faster when cofilin is overexpressed (Yap et al, 2005). The increase in cell motility is dependent on intracellular cofilin concentration, and is likely to contribute to increased invasiveness. We investigate if cofilin is also able to modify other tumourigenic properties.
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Figure 1: Phalloidin staining of the actin cytoskeleton (red fluorescence) in glioblastoma cells. Actin-rich structures include the cell cortex, lamellipodia and stress fibres (actin-myosin bundles spread across the cells). Cells which overexpress cofilin have been engineered to express EGFP (enhanced green fluorescent protein). |
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Figure 2: Cofilin is recruited to the leading edge of a moving glioblastoma cell (arrowed red fluorescent edge). Cofilin was detected by immunochemistry. Both images were obtained by confocal microscopy |