Humic acid induces apoptosis in human premyelocytic leukemia HL-60 cells.
It has been shown that humic acid (HA), a phenolic polymer, exhibits pro-oxidant and cytotoxic effects. In this study, HA induction of apoptosis was studied using cultured human premyelocytic leukemia HL-60 cells. Treatment at a range of HA concentrations (50-400 microg/ml) resulted in dose-and time-dependent sequences of events marked by apoptosis, as demonstrated through by apoptotic features such as loss of cell viability, chromatin condensation, and internucleosomal DNA fragmentation. This HA-induced apoptosis in the HL-60 cells was mainly associated with the release of cytochrome c from the mitochondria. Furthermore, apoptosis in the HL-60 cells was accompanied by the activation of caspase-3 and the specific proteolytic cleavage of poly (ADP-ribose) polymerase (PARP), a major component in the apoptotic cell death mechanism. Although the HA-induced apoptosis was associated with Bax protein levels, negligible Bcl-2 reduction was observed. Analysis of the data reported herein reveals that HA exerts antiproliferative action and growth inhibition on HL-60 cells through induction of apoptosis, which may have anticancer properties potentially useful for the development of new drug products.
Yang
Hsin-Ling
HL
Institute of Nutrition, China Medical University, Taichung, Taiwan.
Hseu
You-Cheng
YC
Hseu
Yi-Ting
YT
Lu
Fung-Jou
FJ
Lin
Elong
E
Lai
Jim-Shoung
JS
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D004587:Electrophoresis, Agar Gel; D018922:HL-60 Cells; D006801:Humans; D006812:Humic Substances; D020287:In Situ Nick-End Labeling; D009569:Nitric Oxide / Q000378:metabolism; D017239:Paclitaxel / Q000494:pharmacology; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D011506:Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis; D051028:bcl-2-Associated X Protein
D000972:Antineoplastic Agents, Phytogenic; C494826:BAX protein, human; D006812:Humic Substances; D011506:Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D009569:Nitric Oxide; D045304:Cytochromes c; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D017239:Paclitaxel