High incidence of LRAT promoter hypermethylation in colorectal cancer correlates with tumor stage Journal Article


Authors: Cheng, Y. W.; Pincas, H.; Huang, J.; Zachariah, E.; Zeng, Z.; Notterman, D. A.; Paty, P.; Barany, F.
Article Title: High incidence of LRAT promoter hypermethylation in colorectal cancer correlates with tumor stage
Abstract: Lecithin:retinol acyltransferase (LRAT) is a major enzyme involved in vitamin A/retinol metabolism, which regulates various physiological processes like cell proliferation and differentiation. LRAT expression is reduced in numerous cancers, yet the underlying mechanisms have remained undefined. We hypothesized that methylation silencing may contribute to decreased LRAT gene expression in colorectal cancer (CRC). LRAT hypermethylation status was analyzed in five CRC cell lines, 167 colorectal tumors, and 69 adjacent normal colonic mucosae, using a quantitative bisulfite/PCR/LDR/Universal Array assay. LRAT transcription levels were determined by real-time RT-PCR in a subset of tumors and matched normal tissues and in CRC cell lines that were treated with a demethylating agent, 5-aza-2′-deoxycytidine. The incidence of LRAT hypermethylation was significantly higher in colorectal tumors than in adjacent normal mucosae (p = 0.0025). Aberrant methylation occurred in 51 % of microsatellite-stable CRCs, in 84 % of microsatellite-unstable CRCs, and in 12 out of 13 colonic polyps. The number of hypermethylated LRAT events was inversely correlated with CRC stage (p < 0.0001). Importantly, LRAT hypermethylation was associated with decreased mRNA level in CRC clinical specimens, and demethylation treatment resulted in LRAT transcriptional reactivation. Our data support the idea that LRAT promoter hypermethylation associates with LRAT gene expression in CRC. The higher frequency of LRAT hypermethylation in colonic polyps and early-stage CRCs indicates that it may occur early in malignant progression.
Keywords: adult; aged; human cell; promoter region; cancer staging; colorectal cancer; reverse transcription polymerase chain reaction; gene expression; dna methylation; messenger rna; 5' untranslated region; cpg island; microsatellite instability; 5 aza 2' deoxycytidine; real time polymerase chain reaction; bisulfite; demethylation; lecithin retinol acyltransferase; cpg methylation; human; male; female; article; thermostable ligase; lrat; universal microarray
Journal Title: Medical Oncology
Volume: 31
Issue: 11
ISSN: 1357-0560
Publisher: Humana Press Inc  
Date Published: 2014-11-01
Start Page: 254
Language: English
DOI: 10.1007/s12032-014-0254-7
PROVIDER: scopus
PUBMED: 25260806
PMCID: PMC4386722
DOI/URL:
Notes: Article #254 -- Article length: 8 pages -- Export Date: 2 February 2015 -- Source: Scopus
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  1. Philip B Paty
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  2. Zhaoshi Zeng
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