A common virus can kill cancer tumours in mice

Scientists have managed to wipe out tumours in mice using a common virus that tricks cancer cells into self-destruction. The research was carried out at the Swiss Institute for Experimental Cancer Research in Epalinges. The research involves a virus that is believed to be harmless to humans, and a gene called p53 that normally suppresses tumours. In most cancer patients, the p53 gene is defective. The researchers injected human colon cancer cells into a group of laboratory mice, followed by the virus two days later. Only two of the 12 rodents later formed tumours. In mice with existing colon cancer tumours, injections of the virus eliminated tumours in six of the 10 rodents. When a cancer cell encounters the virus, it apparently interprets the unusual hairpin-like portion of the virus' DNA as damage to its own DNA. The cell tries to rid itself of the damage and ends up self-destructing. The researchers hope to pinpoint the precise feature that sends cancer cells to their death. If they are successful, it may be possible to develop a drug mimicking these effects. It is too early to know if the approach might work in humans. Many treatments that look promising in mice prove disappointing when they are tested on people. However, the research sheds light on something scientists have noticed for years. Some viruses harm cancer cells but leave normal, healthy cells unscathed.