Viruses have infected humans for millions of years, ever since the divergence from chimpanzees. Some viral infections are short-term, such as influenza, while others cause longer, more serious infections. A prime example of the latter is human immunodeficiency virus (HIV). This kind of virus is known as a retrovirus; these viruses enter cells and insert their genes into human DNA. The natural processes in which our cells create proteins from genes occurs in these viruses too, producing copies of the virus which can infect more cells. If retroviruses infect germ cells and do not produce a sufficient viral infection, the virus may be passed on through generations (Weiss, 2006). Retroviruses in which this occurs are called endogenous retroviruses, specifically HERVs in humans. Many families of HERV exist, with HERV-K being the most active. HERV-K consists of genes required to create new viruses, flanked by long repeat sequences known as LTRs. However, most of the 127 different HERV-K insertions have been broken down so that only the LTRs remain (Pačes et al, 2002). As such, HERVs were long thought to be unimportant in disease, though work since suggests otherwise.
HERV-K, cancer, hepatocellular carcinoma,
Massey, Niall
Faculty of Health and Life Sciences
Year: 2017
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