Phylogeny of new human endogenous retroviral element HERV-S LTR in human cancer cells

摘要

A new human endogenous retroviral family (HERV-S) was recently identified from a human X chromosome that was 6.7 kb in length and had a typical retroviral structure with LTR-gag-pol-env-LTR. Using the PCR and sequencing approach, we investigated LTRelements of the HERV-S family from genomic DNA of the human cancer cells (MCF7, SiHa, HepG2, 2F7, AZ521). Seven LTR elements were newly identified from the human cancer cells and had a high degree of sequence similarity with that of the HERV-S. Phylogenetic analysis from the HERV-S family showed that the LTR elements were mainly divided into 2 groups through evolutionary divergence in human evolution, suggesting that multi-copy of the HERV-S LTR elements could exist the human genome with at least two different types of HERV-S. These HERV-S LTR elements deserve further investigation as potential leads in the study of human cancers.