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Interferon-induced transmembrane protein (IFITM) is reported to be frequently overexpressed in colorectal tumors. This study aimed to determine the usefulness of detecting fecal IFITM messenger RNA (mRNA) by real-time reverse-transcription polymerase chain reaction (RT-PCR) for colorectal cancer (CRC) screening. This pilot study included 21 patients with CRC and 23 healthy controls. Total RNA was isolated from the feces of the patients, and the expression levels of the mRNA of IFITM1, IFITM2 and IFITM3 were measured by real-time RT-PCR to detect CRC. Receiver operating characteristic curves of respective genes were generated, and the area under the curve (AUC), sensitivity and specificity were determined. When the 44 patients were analyzed, the AUCs of fecal IFITM1, IFITM2 and IFITM3 expression analysis were 0.82, 0.80 and 0.65, respectively. The sensitivities were 67% [14/21; 95% confidence interval (CI) 43–85%], 67% (14/21; 95% CI 43–85%) and 71% (15/21; 95% CI 48–89%), respectively; and the specificities were 96% (1/23; 95% CI 78–100%), 96% (1/23; 95% CI 78–100%) and 61% (9/23; 95% CI 39–80%), respectively. When IFITM1 and IFITM2 were combined, the sensitivity was 86% (18/21; 95% CI 64–97%) and the specificity was 96% (1/23; 95% CI 78–100%). The fecal expression analysis of IFITM1 and IFITM2 mRNA by real-time RT-PCR for CRC screening exhibited high specificities, and the sensitivity was further improved by combining IFITM1 and IFITM2.

Hedgehog-interacting protein (HIP) was identified as a putative antagonist of the hedgehog (Hh) pathway and as a target of Hh signaling. Our aim was to clarify the expression profiles and epigenetic alterations of the HIP gene in gastrointestinal cancer. The expression and promoter epigenetic status of HIP in cancer cell lines and freshly resected gastrointestinal cancer tissues were examined using RT-PCR, tissue microarray analysis, methylation-specific PCR, and chromatin immunoprecipitation assay. Cells were treated with the demethylating agent 5-aza-2'-deoxycytidine and/or histone deacetylase inhibitor trichostatin A. WST-8 assays and In Vitro invasion assays after treatment with HIP-specific siRNA were performed. HIP expression levels were reduced in most of the gastrointestinal cancer cell lines and in a certain subset of cancer tissues, and these were correlated with promoter hypermethylation. A heterochromatic structure characterized by neither acetylated H3 nor acetylated H4, and histone H3 lysine 9 hypermethylation and histone H3 lysine 4 hypomethylation was observed in cancer cells in which the HIP gene was aberrantly silenced. On the other hand, overexpression of the HIP gene was also found in some cancer tissues and there were significant correlations between protein expression levels of HIP and those of Sonic hedgehog (Shh), Indian hedgehog, Patched, and glioma-associated oncogene homolog-1. An association was found between lymph node metastasis and HIP silencing in colorectal cancer tissues with strong Shh expression and between advanced TNM stage and HIP silencing in diffuse-type gastric cancer tissues with strong Shh expression. Down-regulation of HIP expression by siRNA resulted in a significant increase in colon cancer cell growth and invasion In Vitro. Silencing of the HIP gene due to hypermethylation and chromatin remodeling appears to be frequently involved in gastrointestinal tumorigenesis.

To clarify alterations of Dickkopfs (Dkks) and Kremen2 (Krm2) in gastrointestinal cancer.We investigated the expression profiles and epigenetic alterations of Dkks and Krm2 genes in gastrointestinal cancer using RT-PCR, tissue microarray analysis, and methylation specific PCR (MSP). Cancer cells were treated with the demethylating agent and/or histone deacetylase inhibitor. WST-8 assays and in vitro invasion assays after treatment with specific siRNA for those genes were performed.Dkks and Krm2 expression levels were reduced in a certain subset of the gastrointestinal cancer cell lines and cancer tissues. This was correlated with promoter hypermethylation. There were significant correlations between Dkks over-expression levels and beta-catenin over-expression in colorectal cancer. In colorectal cancers with beta-catenin over-expression, Dkk-1 expression levels were significantly lower in those with lymph node metastases than in those without. Down-regulation of Dkks expression by siRNA resulted in a significant increase in cancer cell growth and invasiveness in vitro.Down-regulation of the Dkks associated to promoter hypermethylation appears to be frequently involved in gastrointestinal tumorigenesis.