Aberrant methylation of gene promoters and corresponding loss of gene expression plays a critical role in the initiation and progression of colorectal cancer. An IL-6-type cytokine receptor, leukemia inhibitory factor receptor (LIFR), is a component of cell-surface receptor complexes for multi-functional cytokines such as LIF Herein, we report that LIFR is methylated in human colon cancer. LIFR promoter was methylated in primary tumor tissues with high frequency (65%, 52/80). Quantitative methylation-specific PCR (TaqMan-MSP) demonstrated differential promoter methylation of LIFR in primary colorectal cancer tissues as compared to normal colon tissues (5%, 4/80). LIFR methylation was not detectable in 13 normal colon mucosa samples obtained from patients without cancer. The mRNA expression of LIFR was significantly down-regulated in colon cancer tissues as compared to corresponding normal tissues. A strong expression of LIFR protein was observed in all non-malignant normal and adjacent normal colon mucosa tissues whereas down-regulated LIFR protein expression was observed in primary tumors. These results demonstrate that cancer-specific methylation and a specific decrease of LIFR expression are a common inactivation event in colon cancer development.
- Colorectal carcinoma
- Leukemia inhibitory factor receptor
ASJC Scopus subject areas
- Cancer Research