[Oncogenic viruses and cancer].

Oncogenic viruses (oncoviruses) are implicated in approximately 12% of all human cancers. Currently, the viruses known to cause human cancer are: Hepatitis B and C viruses (HBV and HCV), Human Papillomaviruses (HPV), Merkel Cell Polyomavirus (MCV), Human Herpesvirus-8 (HHV-8), Epstein-Barr Virus (EBV) and Human T-cell lymphotropic virus-1 (HTLV-1). However, oncoviruses are not complete carcinogens, need additional factors andisplay different roles in transformation. Oncoviruses can directly disrupt important regulatory cell genes by inserting virus genom into the DNA of the host cell. They also contain their own genes that damage the regulation of the cell. Some viruses have v-onc that cause disregulation of cellular processes and can lead to cancerous growth.