Regensburg 2013 – scientific programme

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BP: Fachverband Biologische Physik

BP 1: Cell migration

BP 1.6: Talk

Monday, March 11, 2013, 11:00–11:15, H43

Mechanics of bleb formation in filamin-negative cancer cells — Julia Peukes and •Timo Betz — Institut Curie, UMR 168, Paris, France

The formation of cellular blebs is a well described dynamical process that can be associated with cell motility, cell division and apoptosis. While recent research has shown a direct relation between cell contractility, cell cortex mechanics and bleb formation, a detailed mechanical model of cell bleb formation containing quantitative values for the mechanical parameters is still under work. Here we show new quantification of the membrane advancement of filamin negative cancer cells during bleb formation as measured by an interferometric technique that gives sub-nm precision at kHz repetition rate. These new experiments allow to determine the fluctuations of the cell bleb membrane during the extension of the bleb, the polymerization of the actin cortex and the myosin driven bleb retraction. Using simple arguments we can translate the fluctuations into an effective actin-cortex tension that is consistent with previous measurements. More detailed analysis of the fluctuation shows mechanical details of the different bleb phases. Furthermore, we can identify clear separations of the bleb growth rates into distinct extension velocity regimes that we attribute to different levels of the actin polymerization under the cell membrane. These findings give hints towards a more detailed model on the different events involved in cellular blebbing.