[Apoptosis of human leukemia HL-60 cells induced by rhabdastrellic acid-A and its mechanisms].

Abstract

BACKGROUND & OBJECTIVE:

Rhabdastrellic acid-A is an isomalabaricane triterpenoid isolated from the sponge Rhabdastrella globostellata from South China Sea. Our previous study indicated that rhabdastrellic acid-A can inhibit the proliferation of many types of tumor cells with minor toxicity. This study was to investigate the apoptosis of human leukemia HL-60 cells induced by rhabdastrellic acid-A and its possible mechanisms.

METHODS:

Inhibitory effect of rhabdastrellic acid-A on the proliferation of HL-60 cells was evaluated by MTT assay. DNA fragmentation was analyzed by agarose electrophoresis. Cell morphology was observed under fluorescent microscope. The protein levels of Caspase-3, poly(ADP-ribose) polymerase (PARP), P73, Bcl-2 and Bax were analyzed by Western blot. The expression profile of apoptosis-related genes was analyzed by gene microarray. Reverse transcription-polymerase chain reaction (RT-PCR) was conducted to confirm some altered genes identified by gene microarray.

RESULTS:

Rhabdastrellic acid-A inhibited the proliferation of HL-60 cells and the 50% inhibition concentration (IC50) was (0.64+/-0.21) microg/ml. When treated with 1 microg/ml rhabdastrellic acid-A for 36 h, condensation of nuclear chromatin of HL-60 cells was observed under fluorescent microscope and DNA fragmentation was observed by agarose electrophoresis. Also, rhabdastrellic acid-A induced cleavage of PARP and Caspase-3. The mRNA levels of 44 genes, including p73, JunD, TNFAIP3 and GADD45A, were up-regulated and the mRNA levels of 16 genes, including MAP2K5 and IGF2R, were down-regulated. The results were further confirmed by RT-PCR. The protein level of P73 was up-regulated after rhabdastrellic acid-A treatment.

CONCLUSION:

Rhabdastrellic acid-A could induce the apoptosis of HL-60 cells which may be related to the up-regulation of apoptosis-related genes such as p73 and JunD, and the down-regulation of MAP2K5 and IGF2R.

• Authors: Jing-Feng Guo, Jun-Min Zhou, Gong-Kan Feng, Zong-Chao Liu, Ding-Jun Xiao, Song-Zhi Deng, Rong Deng, Xiao-Feng Zhu
• Journal: Ai zheng = Aizheng = Chinese journal of cancer (Ai Zheng) Vol. 26 Issue 8 Pg. 809-14 (Aug 2007) China
• PMID: 17697538 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA-Binding Proteins
• Nuclear Proteins
• Proto-Oncogene Proteins c-bcl-2
• Proto-Oncogene Proteins c-jun
• Receptor, IGF Type 2
• TP73 protein, human
• Triterpenes
• Tumor Protein p73
• Tumor Suppressor Proteins
• bcl-2-Associated X Protein
• rhabdastrellic acid A
• Poly(ADP-ribose) Polymerases
• MAP Kinase Kinase 5
• MAP2K5 protein, human
• Caspase 3

Topics

• Apoptosis (drug effects)
• Caspase 3 (metabolism)
• Cell Proliferation (drug effects)
• DNA Fragmentation
• DNA-Binding Proteins (metabolism)
• HL-60 Cells
• Humans
• MAP Kinase Kinase 5 (metabolism)
• Nuclear Proteins (metabolism)
• Poly(ADP-ribose) Polymerases (metabolism)
• Proto-Oncogene Proteins c-bcl-2 (metabolism)
• Proto-Oncogene Proteins c-jun (metabolism)
• Receptor, IGF Type 2 (metabolism)
• Triterpenes (pharmacology)
• Tumor Protein p73
• Tumor Suppressor Proteins (metabolism)
• bcl-2-Associated X Protein (metabolism)