Arming cancer-killing viruses with enzyme from bacteria improves anti-cancer activity.

Arming cancer-killing viruses with enzyme from bacteria improves anti-cancer activity.

Viruses have become one of the more surprising combatants against cancer. Although people often think of viruses as agents that make them sick, researchers have been developing viruses that attack cancer cells and spare healthy cells. These viruses are called oncolytic viruses, and the specificity of this approach allows for a unique, targeted treatment of cancer.

Human glioblastoma, the most common and most fatal type of brain cancer, has been shown to respond to oncolytic viral therapy. The structure of brain tumors, however, poses a significant barrier to the 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.'s effectiveness. Tumor cells embedded in a dense net of sugary proteins, which limit the virus’s capacity to move. Researchers at Ohio State University Medical Center buit a new oncolytic virus that produces an enzymeA protein that speeds up the process of chemical reactions in the body without becoming altered in the process. Almost every biological process is driven by the activity of enzymes. Without enzyme catalysts, the complex reactions that build and break down cell parts would not happen at a rate compatible with life. Enzyme names usually describe the reaction that is being catalyzed and all of them end in -ase. that allows it to overcome this barrier. Chondroitinase is a naturally occurring bacterial enzyme that removes sugar chains, a function that helps break down the physical blocks in brain tumors.  The new activity allowed the oncolytic viruses to maximize their tumor-fighting potential.

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