Effects of glycolic acid on the induction of apoptosis via caspase-3 activation in human leukemia cell line (HL-60).
Apoptosis is a particular process that leads to the programmed cell death, and it has been a potentially therapeutic target of cancer. In this study, we evaluated the possible apoptotic effects of glycolic acid on human leukemia cell line (HL-60) in vitro. The morphological changes, cell viability, apoptosis induction, and caspase-3 activity were measured by phase microscopy, flow cytometry, and Western blot analysis. Morphological changes including shrinkage of cells were clearly demonstrated in HL-60 cells treated with increasing concentrations of glycolic acid. Cell viability was significantly affected by glycolic acid treatment in a dose- and time-dependent manner. In comparison to the control group, glycolic acid treatment had a profound effect in the induction of apoptosis by flow cytometric assays. In the cell cycle analysis, glycolic acid caused the increased percentage of cells in G2/M phase and the decreased expression of the cyclin A and cyclin B1, suggesting the induction of G2/M arrest of cell cycle by glycolic acid. Moreover, glycolic acid treatment promoted caspase-9 and -3 activity in a dose-dependent manner, but caspse-8 activity was not affected during the same process. Glycolic acid co-administrated with broad-spectrum caspase inhibitor, z-VAD-fmk, caspase-3 activity was blunted and apoptosis was also markedly blocked in HL-60 cells. In conclusion, glycolic acid-induced apoptosis in HL-60 cells may be through the activation of caspase-3. Future studies focusing on cell signaling and biological significance of glycolic acid-induced apoptosis would lead to exploring the mechanisms of chemotherapeutic potency of glycolic acid in human cancers.
Yang
Jen-Hung
JH
Department of Dermatology, Chung Shan Medical University Hospital, Taichung 402, Taiwan, ROC.
Chou
Chi-Chung
CC
Cheng
Ya-Wen
YW
Sheen
Lee-Yan
LY
Chou
Ming-Chi
MC
Yu
Hsin-Su
HS
Wei
Yau-Huei
YH
Chung
Jing-Gung
JG
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology*; D000704:Analysis of Variance; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3; D053453:Caspase 9; D061945:Caspase Inhibitors; D020169:Caspases / Q000187:drug effects / Q000378:metabolism*; D002453:Cell Cycle / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D016213:Cyclins / Q000096:biosynthesis; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D005434:Flow Cytometry; D006016:Glycolates / Q000494:pharmacology*; D018922:HL-60 Cells; D006801:Humans; D007202:Indicators and Reagents; D013997:Time Factors
D000590:Amino Acid Chloromethyl Ketones; D061945:Caspase Inhibitors; D016213:Cyclins; D015853:Cysteine Proteinase Inhibitors; D006016:Glycolates; D007202:Indicators and Reagents; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C031149:glycolic acid; D004247:DNA; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases