Expression and significance of melanoma antigen gene-3 in endoplasmic reticulum stress-induced apoptosis of K562 cells.
- Author:
Xian-Qi FENG
1
;
Juan XIAO
;
Shu-Min NIE
;
Fang LIU
;
Yong YOU
;
Ping ZOU
Author Information
1. Department of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China. fxqnsm2000@yahoo.com.cn
- Publication Type:Journal Article
- MeSH:
Antigens, Neoplasm;
genetics;
Apoptosis;
drug effects;
physiology;
Blotting, Western;
Calcium;
metabolism;
Endoplasmic Reticulum;
metabolism;
Heat-Shock Proteins;
metabolism;
Humans;
In Situ Nick-End Labeling;
K562 Cells;
Microscopy, Fluorescence;
Molecular Chaperones;
metabolism;
Neoplasm Proteins;
genetics;
RNA, Messenger;
biosynthesis;
genetics;
Reverse Transcriptase Polymerase Chain Reaction;
Thapsigargin;
pharmacology
- From:
Journal of Experimental Hematology
2005;13(5):741-745
- CountryChina
- Language:Chinese
-
Abstract:
This study was aimed to explore the expression and significance of melanoma antigen gene-3 (MAGE-3) in endoplasmic reticulum stress-induced apoptosis. After the treatment of leukemia cell line K562 and its multidrug-resistant cell line K562/A02 by thapsigargin, intracellular calcium concentrations ([Ca(2+)]i) in K562 and K562/A02 were measured by fluorescence spectrophotometer with calcium sensitive fluorescence indicator Fura-2/AM; expression changes of glucose-regulated protein 78 (GRP78) were detected by Western blot; morphological change of apoptotic cell was investigated by AO/EB fluorescent staining under fluorescent microscope; apoptosis rate was determined by terminal deoxyribonucleotidyl transferase (TdT)-mediated dUTP nick end labelling (TUNEL) staining; the expression of MAGE-3 gene mRNA was detected by RT-PCR. The results showed that (1) thapsigargin induced the enhancement of [Ca(2+)]i with different extent in K562 and K562/A02 cells, and the enhancement of [Ca(2+)]i was dose-dependent in experiment range. At the same time, thapsigargin induced upregulation of GRP78 protein expression and typical apoptotic changes of K562 and K562/A02 cells, apoptotic rate was also dose-dependent in experiment range. The [Ca(2+)]i in K562/A02 cells were higher than that in K562 cells. (2) in the course of endoplasmic reticulum stress-induced apoptosis by thapsigargin, the expression of MAGE-3 gene mRNA was remarkably downregulated. Moreover, the expression of MAGE-3 gene mRNA in K562/A02 cells was higher than that in K562 cells. It is concluded that (1) thapsigargin induces endoplasmic reticulum stress-induced apoptosis of K562 and K562/A02 cells in experiment range, and this may be associated with downregulation of MAGE-3 mRNA expression or MAGE-3 gene may participates in the regulation of endoplasmic reticulum stress-induced apoptosis. (2) MAGE-3 gene may possess anti-apoptotic activity, multidrug resistance in K562/A02 cells can be associated with [Ca(2+)]i increase and upregulation of MAGE-3 expression.
