Mechanisms of Viral Oncogenesis: DNA and RNA Viruses in Human Cancer

With 13% of global tumorigenesis related to pathogens and 2.2 million new tumour cases related to viral infections every year, the role played by viruses in tumorigenesis cannot be ignored. At present, the viruses that have been identified as carcinogenic substances are EB virus, hepatitis B virus, hepatitis C virus, Kaposi's sarcoma virus, human immunodeficiency virus type 1, human T-cell lymphotropic virus type 1, human papillomavirus, Merkel cell polyomavirus, and BK virus. There are also a number of viruses which have not been designated as carcinogens, but which are also closely related to the tumours' development, such as Simian virus 40, JC virus and human cytomegalovirus. Human oncolytic viruses are divided into DNA oncolytic viruses and RNA oncolytic viruses, which are highly diverse and have different tumorigenic mechanisms. This article focuses on these confirmed DNA tumor viruses and RNA tumor viruses, delving into the various tumor types they cause and the mechanisms behind them. Based on the comparative analysis of their oncogenic pathways, we conclude that common mechanisms, such as the disruption of tumor suppressor proteins, chronic inflammation, and immune evasion, presenting actionable targets for both prophylactic intervention and precision therapy against virus-associated cancers.