Identification and detection of a novel human endogenous retrovirus-related gene, and structural characterization of its related elements

Up-regulation of human endogenous retroviruses (HERVs) is associated with many diseases, including cancer. In this study, an H family HERV (HERV-H)-related gene was identified and characterized. Its spliced transcript lacks protein-coding capacity and may belong to the emerging class of noncoding RNAs (ncRNAs). The 1.3-kb RNA consisting of four exons is transcribed from an Alu element upstream of a 5.0-kb structurally incomplete HERV-H element. RT-PCR and quantitative RT-PCR results indicated that expression of this HERV-related transcript was negatively associated with colon, stomach, and kidney cancers. Its expression was induced upon treatment with DNA methylation and histone deacetylation inhibitors. A BLAT search using long terminal repeats (LTRs) identified 50 other LTR homogenous HERV-H elements. Further analysis of these elements revealed that all are structurally incomplete and only five exert transcriptional activity. The results presented here recommend further investigation into a potentially functional HERV-H-related ncRNA.