Increased intake of n-3 polyunsaturated fatty acids elevates the level of apoptosis in the normal sigmoid colon of patients polypectomized for adenomas/tumors.
To clarify preventive effects of n-3 polyunsaturated fatty acids (PUFAs) against colorectal carcinogenesis, we performed a dietary intervention in patients polypectomized for colorectal adenomas/tumors. For the former the following dietary advice was given: (1) decrease intake of fat from 30 to 20% of the total; (2) decrease consumption of n-6PUFAs containing foods, and increase intake of n-3 PUFAs for 2 years. For the comparison group only decreased intake of fat (30-20%) was recommended. Samples of normal sigmoid colon mucosa, obtained by colonoscopic check once a year during the intervention period, were used to investigate COX-2, cell proliferation (Ki67 expression), p53, Bcl-2 and Bax by immunostaining and determine the apoptosis index (AI) by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labeling (TUNEL) in 21 and 20 patients in experimental and comparison groups, respectively, who completed the 2 years of the intervention. After 24 months, the AI and positive cells of Bax and the ratio of Bax/Bcl-2 in normal sigmoid colon mucosa for the experimental group was significantly increased, whereas this change was not found in comparison group. These observations demonstrated for the first time that increased intake of n-3 PUFAs promotes apoptosis of normal colon mucosa in human which is related to effect on Bax or the balance of Bax and Bcl-2.
Cheng
Jinglei
J
Department of Health Promotion and Preventive Medicine, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan.
Ogawa
Kumiko
K
Kuriki
Kiyonori
K
Yokoyama
Yoshifumi
Y
Kamiya
Takeshi
T
Seno
Kyoji
K
Okuyama
Harumi
H
Wang
Jingwen
J
Luo
Chenhong
C
Fujii
Toshiko
T
Ichikawa
Hiromitsu
H
Shirai
Tomoyuki
T
Tokudome
Shinkan
S
D000236:Adenoma / Q000378:metabolism / Q000473:pathology*; D017209:Apoptosis; D002455:Cell Division; D003106:Colon / Q000378:metabolism / Q000473:pathology*; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D015525:Fatty Acids, Omega-3; D005231:Fatty Acids, Unsaturated / Q000493:pharmacokinetics*; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D009092:Mucous Membrane / Q000378:metabolism / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D014280:Triglycerides / Q000493:pharmacokinetics*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D051028:bcl-2-Associated X Protein
C494826:BAX protein, human; D015525:Fatty Acids, Omega-3; D005231:Fatty Acids, Unsaturated; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D014280:Triglycerides; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; C077446:Pikasol