[Hypomethylation of 5'CpG island of insulin-like growth factor binding protein-related protein 1 is associated with its overexpression in colorectal cancer].

Abstract

OBJECTIVE:

To investigate the methylation status of 5'CpG island of insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) in colorectal cancer and its relationship with gene expression and clinicopathologic parameters.

METHODS:

Semi-quantitative reverse transcription-PCR (RT-PCR) was used to detect the expression of IGFBP-rP1 in 46 cases of colorectal cancer and their matched normal mucosa. Methylation-specific PCR (MSP) was applied to evaluate the methylation status of 5'CpG island of IGFBP-rP1. Colon cancer cell lines LoVo and SW620 were treated with demethylation agent 5-aza-2'-deoxycytidine (5-aza-dC), followed by RT-PCR and MSP detection.

RESULTS:

At the mRNA level, the expression of IGFBP-rP1 was higher in colorectal cancer tissue than that in the matched normal mucosa (P < 0.05). IGFBP-rP1 was methylated in 28/46 (60.9%) cases of colorectal cancer and 37/46 (80.4%) matched normal mucosa samples (P < 0.05). A negative correlation was found between IGFBP-rP1 expression and its methylation status. The expression of IGFBP-rP1 was restored in LoVo and SW620 after treatment with 5-aza-dC and MSP confirmation of its demethylation status. No relationships was found between the methylation status and clinicopathologic parameters.

CONCLUSIONS:

IGFBP-rP1 expression is negatively correlated with its methylation status in colorectal cancer. DNA methylation is one of the mechanisms regulating the expression of IGFBP-rP1. Hypomethylation of IGFBP-rP1 gene with its overexpression plays an important role in the initiation and development of colorectal cancer.

• Authors: Jie Lin, Yi-Min Zhu, Li-Na Shao, Qiong Huang, Mao-de Lai
• Journal: Zhonghua bing li xue za zhi = Chinese journal of pathology (Zhonghua Bing Li Xue Za Zhi) Vol. 37 Issue 8 Pg. 512-6 (Aug 2008) ISSN: 0529-5807 [Print] China
• PMID: 19094461 (Publication Type: Journal Article)

Chemical References

• Insulin-Like Growth Factor Binding Proteins
• RNA, Messenger
• insulin-like growth factor binding protein-related protein 1
• Decitabine
• Azacitidine

Topics

• Adult
• Aged
• Aged, 80 and over
• Azacitidine (analogs & derivatives, pharmacology)
• Cell Line, Tumor
• Colorectal Neoplasms (genetics)
• CpG Islands (physiology)
• DNA Methylation
• Decitabine
• Female
• Gene Expression Regulation, Neoplastic
• Humans
• Insulin-Like Growth Factor Binding Proteins (genetics)
• Male
• Middle Aged
• RNA, Messenger (metabolism)
• Reverse Transcriptase Polymerase Chain Reaction (trends)
• Transcription, Genetic