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Association of BCL‐2 with membrane hyperpolarization and radioresistance
Author(s) -
Gilbert Mark S.,
Saad Ali H.,
Rupnow Brent A.,
Knox Susan J.
Publication year - 1996
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/(sici)1097-4652(199607)168:1<114::aid-jcp14>3.0.co;2-7
Subject(s) - hyperpolarization (physics) , transfection , radioresistance , depolarization , ouabain , membrane potential , neomycin , radiosensitivity , biology , cell culture , intracellular , microbiology and biotechnology , chemistry , biophysics , medicine , biochemistry , sodium , genetics , antibiotics , organic chemistry , nuclear magnetic resonance spectroscopy , radiation therapy
The resting membrane potential of parental, neomycin control, and Bcl‐2 transfected cells was measured, and the effect of membrane hyperpolarization or depolarization on radiosensitivity was studied. Bcl‐2 transfected cells were significantly more radioresistant than control cells and were significantly hyperpolarized compared to parental and neomycin control transfected PW and HL60 cells. Hyperpolarization of the parental and neomycin control transfected cells by valinomycin significantly increased the radioresistance of these cells to such an extent that there was no longer a significant difference in the survival of the valinomycin treated and irradiated control cells compared to similarly irradiated Bcl‐2 transfected cells. In contrast, depolarization of the Bcl‐2 transfected PW and HL60 cells decreased the radioresistance of the Bcl‐2 transfectants to a level similar to that of the control cells. The data presented here suggest that overexpression of Bcl‐2 affects membrane potential and that this hyperpolarization is associated with increased radioresistance of cells that overexpress Bcl‐2. Furthermore, Bcl‐2 transfected cells were also less susceptible to the specific Na + /K + ‐ATPase inhibitor ouabain, suggesting that Bcl‐2 may act at the level of the Na + /K + ‐ATPase pump. © 1996 Wiley‐Liss, Inc.