[Expression of methylthioadenosine phosphorylase (MTAP) gene and demethylation of its promoter in human colorectal cancer].

Abstract

BACKGROUND AND OBJECTIVE:

Abnormal expression of 5'-methylthioadenosine phosphorylase (MTAP) is found in various tumor tissues. This study was to explore the correlation of MTAP expression to demethylation of MTAP promoter in colorectal cancer tissues.

METHODS:

The contents of MTAP mRNA in 50 colorectal cancer tissue samples and the adjacent normal tissues were detected by real-time PCR; expression of MTAP protein was detected by immunohistochemistry; methylation of MTAP promoter in colorectal cancer tissues and its adjacent normal tissues were detected by methylation-specified PCR (MSP).

RESULTS:

Compared with the adjacent normal tissues, the expression of MTAP mRNA was dramatically increased in colorectal cancer tissues (P<0.01). The positive rate of MTAP protein in colorectal cancer was significantly higher than that in colorectal adenoma and in adjacent normal tissues (98.0% vs. 85.0% and 12.5%, P<0.05), and the difference of the latter two groups was also significantly different (P<0.01). The methylation frequency of MTAP promoter was significantly lower in colorectal cancer group (32.0%) than in normal tissue (93.8%) and colorectal adenoma (75.0%) groups (P<0.01).

CONCLUSIONS:

Expression of MTAP is significantly higher in human colorectal cancer than in normal colorectal tissues. Demethylation of MTAP promoter may play an important role in up-regulating MTAP expression.

• Authors: Jian-Xin Dou, Wei-Dong Zhang, Wen-Tong Li, Hong-Li Li, Xiao-Shan Cai, Jing Liu
• Journal: Ai zheng = Aizheng = Chinese journal of cancer (Ai Zheng) Vol. 28 Issue 4 Pg. 390-4 (Apr 2009) China
• PMID: 19622299 (Publication Type: English Abstract, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Neoplasm
• RNA, Messenger
• Purine-Nucleoside Phosphorylase
• 5'-methylthioadenosine phosphorylase

Topics

• Adenocarcinoma (genetics, metabolism)
• Adenoma (genetics, metabolism)
• Adult
• Aged
• Colorectal Neoplasms (genetics, metabolism)
• DNA Methylation
• DNA, Neoplasm (genetics)
• Female
• Gene Expression Regulation, Neoplastic
• Humans
• Intestinal Mucosa (metabolism)
• Male
• Middle Aged
• Polymerase Chain Reaction (methods)
• Promoter Regions, Genetic
• Purine-Nucleoside Phosphorylase (genetics, metabolism)
• RNA, Messenger (metabolism)