Adamantyl maleimide induced changes in adhesion molecules and ROS are involved in apoptosis of human gastric cancer cells.
BACKGROUND
We have previously found that N-1-adamantyl maleimide (AMI) inhibited the growth of SC-M1 tumors in vitro and in vivo. The cytotoxicity of AMI on SC-M1 was accompanied by a decrease of adherent cells and the suppressive effect was associated with conformational changes in cell membrane protein. In order to determine the cellular targets of AMI in human gastric cancer SC-M1 cells, we examined AMI-induced changes in the levels of adhesion molecules CD29 (beta 1 integrin) and CD54 (ICAM-1) and GSH. In addition, we also analyzed changes of apoptosis markers such as annexin V binding to membrane and caspase 3 activity in SC-M1 cells after treatment with AMI.


METHODS
Changes in CD29, CD54, annexin V binding and GSH levels were examined using FITC-conjugated antibodies or fluorescence probes and flowcytometry. Caspase 3 activity was assayed with spectrofluorometry.


RESULTS
We found that the expression of CD29 and CD54 on SC-M1 was decreased and the caspase 3 activity was increased during the early apoptosis induced by AMI. Moreover, it was found that the GSH content of the cell was depleted within 30 minutes and then recovered.


CONCLUSIONS
These results suggest that the cell membrane proteins, such as adhesion molecules (CD29, CD54) and intracellular GSH, were the targets of AMI on SC-M1 cells. Since these membrane alterations were prior to apoptosis they may have transduced a death signal to SC-M1 cells.
Wang
J J
JJ
National Taipei College of Nursing, National Yang-Ming University, Taiwan, ROC.
Liu
T Y
TY
Yin
P H
PH
Wu
C W
CW
Chern
Y T
YT
Chi
C W
CW
D000218:Adamantane / Q000031:analogs & derivatives* / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D004790:Enzyme Induction; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D007424:Intracellular Fluid / Q000378:metabolism; D008301:Maleimides / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013274:Stomach Neoplasms; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D019012:Integrin beta1; D008301:Maleimides; D017382:Reactive Oxygen Species; C109726:adamantyl maleimide; D018799:Intercellular Adhesion Molecule-1; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D005978:Glutathione; D000218:Adamantane