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World J Gastroenterol. Apr 21, 2007; 13(15): 2209-2213
Published online Apr 21, 2007. doi: 10.3748/wjg.v13.i15.2209
Expression of p21WAF1 is related to acetylation of histone H3 in total chromatin in human colorectal cancer
Ying-Xuan Chen, Jing-Yuan Fang, Rong Lu, De-Kai Qiu
Ying-Xuan Chen, Jing-Yuan Fang, De-Kai Qiu, Rong-Lu, Department of Gastroenterology, Renji Hospital, Shanghai Institute of Digestive Disease, Shanghai Jiaotong University School of Medicine, Shanghai 200001, China
Author contributions: All authors contributed equally to the work.
Supported by the Major State Basic Research Development Program of China (973 Program), No. 2005CB522400; Shanghai Leading Academic Discipline Project, No. Y0205; and Shanghai Municipal Commission for Science and Technology to FJY, No. 04DZ14006
Correspondence to: Jing-Yuan Fang, MD, PhD, Professor of Medicine, Shanghai Jiaotong University School of Medicine Renji Hospital, Shanghai Institute of Digestive Disease, 145 Shandong Zhong Lu, Shanghai 200001, China. jingyuanfang@yahoo.com
Telephone: +86-21-63200874 Fax: + 86-21-63266027
Received: October 8, 2006
Revised: January 15, 2007
Accepted: March 15, 2007
Published online: April 21, 2007
Abstract

AIM: To explore the relationship between acetylation of histone in total chromatin and p21WAF1 expression regulation in human colorectal carcinoma.

METHODS: We analyzed the expression of tumor suppressor gene p21WAF1 mRNA by RT-PCR or real-time PCR in 33 samples of colorectal cancerous tissue, corresponding para-cancerous tissue and normal colorectal mucosa, and also examined the level of acetylated histone H3 in total chromatin using Western blotting.

RESULTS: The expression level of p21WAF1 mRNA was significantly lower in colorectal cancerous tissue from 33 patients than in para-cancerous tissue and normal colorectal mucosa (2377.95 ± 865.80 vs 3216.58 ± 1149.42 and 3541.61 ± 1433.17 respectively, P < 0.01). In addition, when p21WAF1 mRNA expression was undectectable or at very low level (50% less than that in adjacent tissue and normal colorectal mucosa) in all tissues, the level of acetylated histone H3 in colorectal cancerous tissue was significantly lower than that in corresponding para-cancerous tissue and normal colorectal mucosa in five of seven (71.43%) cases. The transcriptional level of p21WAF1 in colorectal carcinoma might not be associated with its biological behaviors.

CONCLUSION: The down-regulation of p21WAF1 transcription is involved in the tumorigenesis and development of colorectal carcinoma. The down-expression of p21WAF1 mRNA in colorectal carcinoma might be associated with histone hypoacetylation in chromatin but not with biological behaviors.

Keywords: Colorectal cancer; p21WAF1; Histone acetylation