[Assembly of actin filaments induced by sequestration of membrane cholesterol in transformed cells].

Cholesterol is one of the major lipid components of plasma membrane and it plays an important role in various signaling processes in mammalian cells. Our study focused on the role of membrane cholesterol in organization and dynamics of actin cytoskeleton. Experiments were performed on cultured transformed cells characterized by weakly developed actin network and reduced stress fibers--human embryonic kidney HEK293 cells, epidermoid larynx carcinoma HEp2 cells and mouse fibroblasts 3T3-SV40.

[Sensitivity to lysis by natural killers depends on the integrity of lipid rafts in plasma membrane of transformed cells].

The present work focused on the role of cholesterol-rich membrane microdomains (rafts) in cellular mechanisms of innate immunity and anticancer defence. The lytic effect of natural killers (NK) was examined in dependence on cholesterol content in transformed target cells. In the current study, K562 human erythroleukaemia cells were the targets.

[Functional properties of sodium channels in cholesterol-depleted K562 cells].

The level of cellular cholesterol is known to determine functional compartmentalization of membrane lipids into ordered microdomains (rafts). Lipid rafts are assumed to play an essential role in the interactions between cell membrane and cortical cytoskeleton. As we have shown earlier, the activity of non-voltage-gated sodium channels in K562 human leukaemia cells is critically dependent on actin cytoskeleton organization.