[Role of Na(+)/H(+) exchanger 1 in apoptosis of HL-60 cells induced by etoposide and its mechanism].
This study was aimed to investigate the role of Na(+)/H(+) exchanger 1 (NHE1) in apoptosis of HL-60 cells induced by etoposide. Real-time quantitative PCR (RQ-PCR) and Western blot methods were used to determine the expression of NHE1 in HL-60 cells after the treatment with etoposide. Meanwhile, laser scanning confocal microscopy was used to test the intracellular pH (pHi) of HL-60 cells. Cell apoptosis was measured by DNA fragmentation and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. The results showed that etoposide induced cell apoptosis after treatment for 24 hours. The expression level of NHE1 mRNA increased by 2.848 +/- 0.886 times after treatment with etoposide for 12 hours (p < 0.01), and the expression of NHE1 protein was also up-regulated (p < 0.01). The pHi of HL-60 cells increased from 7.11 to 7.46 after treatment with etoposide for 24 hours. Treatment with cariporide could block etoposide-induced alkalinisation and enhance the apoptosis HL-60 cells. It is concluded that the expression of NHE1 is up-regulated in process of apoptosis of HL-60 cells induced by etoposide and the apoptosis depends on the pH increase caused by NHE1 higher expression.
Yan
Yan
Y
National key Laboratory of Experimental Hematology, Institute of Hematology and Hospital of Blood Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China.
Li
Hua-Wen
HW
Li
Qing-Hua
QH
Hu
Rong-Hua
RH
Pang
Tian-Xiang
TX
D017209:Apoptosis / Q000187:drug effects*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D053938:DNA Fragmentation; D005047:Etoposide / Q000494:pharmacology*; D015973:Gene Expression Regulation, Leukemic; D018922:HL-60 Cells; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*
D027682:Cation Transport Proteins; D012333:RNA, Messenger; C490998:SLC9A1 protein, human; D000074082:Sodium-Hydrogen Exchanger 1; D017923:Sodium-Hydrogen Exchangers; D005047:Etoposide