The human T-cell lymphotropic virusThe smallest type of organism known. A single virus particle (called a virion) is much smaller than a cell. Viruses reproduce by invading cells and forcing the cells to make progeny virions. Viruses generally have specific host cells which they infect. Some virus types are associated with specific cancers and can convert normal cells into cancer cells. Examples of viruses associated with cancer are: papillomavirus-cervical cancer, hepatitis virus-liver cancer, Epstein-Barr virus-Burkitt's lymphoma. Virus-induced transformation of cells was one of the very first model systems for the study of cancer. Viruses have also been a key tool in the identification of many oncogenes. Because of their great ability to enter target cells viruses such as adenoviruses are being examined for their ability to deliver genes to cancer cells. 1 (HTLV-1) is a human retrovirusA virus that has RNA as its genetic material. Since the most common genetic material for organisms is DNA, these viruses are sort of backwards, hence the name retro-virus. During infection retroviruses may rarely take some cellular DNA with them when they leave the cell. Some of the first oncogenes were discovered because they were carried by retroviruses. These retroviruses were found to cause cancer and it was later shown to be due to the presence of the altered oncogene in the virus. that causes leukemiaA cancer affecting the cells that develop into white or red blood cells. Both of these cell types originate from stem cells in bone marrow. Red blood cells function to carry oxygen to our tissues and the white cells (leukocytes) are part of our immune system. The cancerous cells often accumulate in the blood.. New research has helped to define exactly how the virus is able to take over normal cells. The virus produces a proteinOne of the four basic types of biomolecule. Proteins are polymers made up of strings of amino acids. Proteins serve many functions in organisms including transport of molecules, structure, cell adhesion and as signaling molecules such as hormones. Many transcription factors, including p53 and Rb are proteins. (p30) that binds with several key cell regulators (ATM and REGγ). ATM is involved in recognition of DNAAbbreviation for deoxyribonucleic acid. Composed of very long strings of nucleotides, which are abbreviated as A, C, G and T. DNA is the storage form of our genetic material. All of the instructions for the production of proteins are encoded in our DNA. damage and REGγ helps to control the destruction of unwanted proteins. The interaction between the viral protein and the cellular proteins is thought to allow the cells to live, even though they are infected.
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