Alu-related transcript of TJP2 gene as a marker for colorectal cancer.

Identifying diagnostic markers is very important in cancer biology. Transposable elements (TEs) account for 45% of the human genome and are usually silent in normal tissues. Contrary to this, in cancer tissues, TEs have been found to be expressed specifically with genomic instability. Here, we investigated the transcripts related to TEs using bioinformatic tools and RT-PCR analysis in tumor and adjacent normal tissues as well as in cancer cell lines. From this analysis, we identified the Alu-related transcript of TJP2 gene (TJP2-Alu transcript) that was differentially expressed between tumor and normal tissues. Its expression was higher in colon cancer cell lines and tumor tissues of colorectal cancer patients. These results could contribute to a better understanding of the involvement of TEs in human colorectal cancer, and to evaluating their potential as diagnostic markers for colorectal cancer.