Scientists unveil keys to refine chemotherapy drugs

2011/07/22 Taipei, July 22 (CNA) A team of Taiwan scientists uncovered how a common type of anti-cancer medicine fights off malignant cells, a mechanism that was unknown to science, said National Taiwan University (NTU) Friday. Describing the discovery as a "milestone" in cancer drug development, Chan Nei-li, a specialist in structural biology and a faculty member of NTU's College of Medicine, said that the finding could help pharmacists worldwide come up with drugs that have fewer side effects on cancer patients. Chan and his research team found that etoposide, a widely used chemotherapy drug, kills cancer cells by interacting with type II topoisomerases, which cancer cells rely on heavily for existence. Type II topoisomerases is an enzyme that can cause DNA strands of cancer cells to break permanently, and by doing so kills them. "Although etoposide has been around for 30 years, we were still unsure of its cancer cell killing mechanism," said Li Tsai-kun, a research member. "Now that we understand how it works, our next step is to modify the chemical structure of the drug to reduce complications." The anti-cancer agent is prescribed for various cancers and its side effects include low blood pressure, hair loss, pain, constipation, and acute myeloid leukemia. Chan said that they are trying to patent the finding, which was published in the renowned journal Science on July 22, 2010.