Author/Editor		Šentjurc, Marjeta; Zorec, Maša; Čemažar, Maja; Auersperg, Marija; Serša, Gregor
Title		Effect of vinblastine on cell membrane fluidity in vinblastine-sensitive and -resistant HeLa cells
Type		članek
Source		Cancer Lett
Vol. and No.		Letnik 130, št. 1-2
Publication year		1998
Volume		str. 183-90
Language		eng
Abstract		The electron paramagnetic resonance method (EPR) was used to study effects of vibrasine (VLB) on cell membrane fluidity in wild-type HeLa cells (HeLa K) and its subclone, which is resistant to several drugs (HeLa CA). HeLa CA cells, obtained by treatment of HeLa K with CDDP, were found to be more resistant to VLB than too CDDP. The experimentally observed EPR spectra were corelated with the calculated spectra obtained by computer simulation. The results that the cell membrane of HeLa K and HeLa CA cells is heterogenous and can be described with at least three types of coexisting domains with different fluidity characteristics. The two more fluid domains of HeLa CA cells were found to be more fluid than in HeLaK cells. The fluidity of the less fluid domain remained unchanged but its portion in the membrane was increased. VLB treatment did not affect the membrane fluidity of HeLa CA cells significantly. On the other hand, 1h of treatment of HeLa K cells with 1 ng/ml VLB did not change the fluidity of membrane domains but decreased the portion of the less fluid domains. This was also reflected in an average increase of the entire membrane fluidity. The observed changes were detected at VLB concentrations which were far bellow the cytotoxic level.
Descriptors		HELA CELLS VINBLASTINE MEMBRANE FLUIDITY SPIN LABELS ELECTRON SPIN RESONANCE SPECTROSCOPY COMPUTER SIMULATION