Apoptotic effect of Epigallocatechin-3-gallate on the human gastric cancer cell line MKN45 via activation of the mitochondrial pathway.
OBJECTIVE
To investigate whether Epigallocatechin-3-gallate (EGCG) can induce apoptosis of the gastric cancer cell line MKN45 and its apoptotic pathway.


METHODS
To determine this, apoptotic rates of MKN45 cells after EGCG treatment with or without caspase-3 inhibitor were evaluated by Annexin V-FITC + PI staining The influence of EGCG on the activity of caspase-3 in the MKN45 cells was determined by ELISA. By Rhodamine123 staining, the membrane potential change of the mitochondrion was also investigated, and mRNAs and protein expression of the bcl-2 family were analyzed by RT-PCR and Western blot.


RESULTS
EGCG can induce apoptosis of MKN45 cells in time- and dose-dependent manner. Eight hours after EGCG treatment, the activity of caspase-3 in the MKN45 increased, especially 12 h after treatment. The mitochondrial membrane potential was significantly weakened 4 h after EGCG insult. The mRNA and protein expression levels of pro-apoptotic members, such as Bax, Bid and Bad, were upregulated gradually as treated time increased. Moreover, the mRNA and protein expression levels of anti-apoptotic members, such as Bcl-xL and Bcl-2, were inhibited.


CONCLUSIONS
These data support that EGCG can induce apoptosis of the human gastric cancer cell line MKN45, and the effect is in a time- and dose-dependent manner. The apoptotic pathway triggered by EGCG in MKN45 is mitochondrial-dependent.
Ran
Zhi-Hua
ZH
Department of Gastroenterology, Renji Hospital, Shanghai Institute of Digestive Disease, Shanghai 200001, China. z-ran@online.sh.cn
Xu
Qi
Q
Tong
Jin-Lu
JL
Xiao
Shu-Dong
SD
D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects / Q000502:physiology; D008928:Mitochondria / Q000187:drug effects* / Q000502:physiology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology*; D013997:Time Factors
D016588:Anticarcinogenic Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D002392:Catechin; C045651:epigallocatechin gallate; D053148:Caspase 3
Int J Cancer. 2003 Oct 10;106(6):856-62
12918062
Biochem Biophys Res Commun. 2000 Apr 21;270(3):793-7
10772904
FASEB J. 2003 Apr;17(6):702-4
12586742
Oncol Rep. 1998 Mar-Apr;5(2):527-9
9468594
Carcinogenesis. 2003 Aug;24(8):1369-78
12819184
Toxicol Sci. 1999 Dec;52(2 Suppl):111-7
10630599
Cancer Res. 1999 Sep 15;59(18):4610-7
10493515
Science. 2004 Jul 30;305(5684):626-9
15286356
Cell. 2004 Jan 23;116(2):205-19
14744432
Genes Dev. 2002 Jan 1;16(1):33-45
11782443
J Nutr. 2003 Oct;133(10):3262S-3267S
14519824
Nutr Rev. 2004 May;62(5):204-11
15212320
World J Gastroenterol. 2004 Jul 1;10(13):1984-8
15222052
Biochem Biophys Res Commun. 2001 Aug 3;285(5):1102-6
11478767
Cancer Res. 2003 Dec 1;63(23):8118-21
14678963
Cancer Res. 1998 Sep 15;58(18):4096-101
9751618
Mutat Res. 1999 Jul 16;428(1-2):339-44
10518005
Int J Oncol. 2004 Mar;24(3):703-10
14767556
Int J Cancer. 2005 Apr 20;114(4):513-21
15609335
J Nutr. 2000 Feb;130(2S Suppl):472S-478S
10721932