The molecular mechanisms of virus-induced human cancers.

Cancer is a serious public health problem globally. Many human cancers are induced by viruses. Understanding of the mechanisms by which oncogenic (tumorigenic) viruses induce cancer is essential in the prevention and control of cancer. This review covers comprehensive characteristics and molecular mechanisms of the main virus-attributed cancers caused by human papillomavirus, hepatitis B virus, hepatitis C virus, Epstein-Barr virus, human herpesvirus type 8, human T-cell lymphotropic virus, human polyomaviruses, Merkel cell polyomavirus, and HIV. Oncogenic viruses employ biological processes to replicate and avoid detection by host cell immune systems. Tumorigenic infectious agents activate oncogenes in a variety of ways, allowing the pathogen to block host tumour suppressor proteins, inhibit apoptosis, enhance cell proliferation, and promote invasion of host cells. Furthermore, this review assesses many pathways of viruses linked to cancer, including host cellular communication perturbation, DNA damage mechanisms, immunity, and microRNA targets that promote the beginning and progression of cancer. The current cancer prevention is primarily focused on non-communicable diseases, but infection-attributable cancer also needs attention to significantly reduce the rising cancer burden and related deaths.