Torque Teno Virus 10 Isolated by Genome Amplification Techniques from a Patient with Concomitant Chronic Lymphocytic Leukemia and Polycythemia Vera

摘要

The direct role of infectious agents in the development of cancer was initially demonstrated in 1911 by the discovery of Rous sarcoma virus, which causes sarcomas in chickens (1). Such agents have also been identified in a few human cancers, such as human papilloma virus (HPV)in cervical carcinoma, human T-cell lymphotropic virus-1 (HTLV-1) in adult T-cell leukemia and human herpesvirus 8 (HHV-8) in Kaposi's sarcoma (2). Additionally, infectious agents may have an indirect role in cancer development by promoting an inflammatory environment that favors tumor growth, as exemplifiedby the association of Helicobacter pylori infection with stomach cancer and mucosa-associated lymphoma (2). Despite these examples, the identification of infectious agents in human cancer has been difficult, in part because cell culture techniques are needed to produce large quantities of infectious agents in vitro. Use of modern ge-nomic amplification techniques circumvents this difficulty and provides the ability to isolate and identify unique de-oxyribonudeic acid (DNA) sequences of putative infectious agents obtained from small tissue samples containing few infectious particles (3).