Important note: Information in this article was accurate in 1990. The state of the art may have changed since the publication date.
PRINCIPLES OF CARCINOGENESIS: VIRAL
Cancer: Principles and Practice of Oncology. Third Edition. DeVita VT Jr. et al, eds. Philadelphia, Lippincott, p. 149-66, 1989.. Unique Identifier : AIDSLINE ICDB/90666955 Howley PM; Lab. of Tumor Virus Biology, NCI, Bethesda, MD
Abstract:
The observation that cell-free extracts from a sarcoma in chickens could transmit sarcoma to injected animals was made by Peyton Rous in 1911. That this represented viral transmission of cancer was not appreciated for decades. Several human viruses have oncogenic properties, although not all have been demonstrated to cause cancer in humans. Viral carcinogenesis is reviewed, including human retroviruses (human T-cell lymphadenotropic virus type 1 [HTLV-1], HTLV-2, HIV, and their mechanisms of transformation), hepatitis B virus (HBV: discovery, HBV viral DNA, HBV replication, and HBV and hepatocellular carcinoma), papillomaviruses (biology of human papillomavirus [HPV] infection, HPV genomic organization, papillomaviruses and cancer, epidermodysplasia verruciformis, genital carcinomas, and other human cancers associated with HPV), and Epstein-Barr virus (EBV: EBV viral genome, EBV antigens, Burkitt's lymphoma, nasopharyngeal carcinoma, and lymphoma in immunodeficient individuals). Human viruses with oncogenic properties include adenoviruses 2, 5, and 12; HBV; EBV; HPVs; polyomaviruses BK and JC; and retroviruses HTLV-1 and -2. For several of these viruses, a cofactor is needed to yield carcinogenic effects. Examples include aflatoxin, alcohol, and smoking for hepadnavirus; malaria, immunodeficiency, or nitrosamines for EBV; and smoking, genetic disorders, or sunlight for HPVs. The acute transforming retroviruses are defective viruses. In addition to losing viral gene segments, they have acquired onc sequences from the cellular genome. The transregulatory retroviruses contain sequences 3' to the env gene that encode regulatory factors. This region has been referred to as the X region and encodes the TAT gene among other regulatory factors. A feature of carcinogenic progression with HPVs is the synergy between the virus and carcinogenic external factors (eg, UV light and herpes simplex infection). EBV was the first human tumor virus to be recognized; it was associated with lymphoma by Dennis Burkitt in 1958. The EBV genome has now been sequenced in its entirety. Nasopharyngeal carcinoma has also been linked to EBV. Since incidence of this disease among individuals of Chinese descent remains high irrespective of where they live, a genetic susceptibility has been proposed. (254 Refs)
Keywords: Animal *Carcinogenicity Tests Cell Line, Transformed Cell Transformation, Viral/GENETICS/*PHYSIOLOGY Cocarcinogenesis Hepatitis B Virus/GENETICS Herpesvirus 4, Human/GENETICS Human Papillomavirus/GENETICS Proto-Oncogene Proteins/PHYSIOLOGY Retroviridae/GENETICS Risk Factors Tumor Virus Infections/*ETIOLOGY/GENETICS/MICROBIOLOGY MONOGRAPH REVIEW REVIEW, TUTORIAL 901230
M90C3740
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Important note: Information in this article was accurate in 1990. The state of the art may have changed since the publication date.
