癌症疫苗-精品文档

接种疫苗预防脑瘤将成为可能。The story began a few years ago when Charles Cobbs of the California Pacific Medical Centre Research Institute in San Francisco found something odd about glioblastomas. He noticed they usually have a form of herpes, called cytomegalovirus, active within them. It is not that catching cytomegalovirus automatically causes a brain tumour—the virus is found, inactive, in about 80% of the population. Nevertheless, there is clearly some connection between virus and tumour, a connection reinforced by Dr Cobbs’s discovery that the virus appears to dwell inside the tumour but not in the healthy tissue surrounding it. This led him to speculate that the virus may be creating the tumour as a safe haven to support its own existence.After learning about Dr Cobbs’s work, Dr Mitchell and his colleagues first confirmed the basic findings. They discovered cytomegalovirus in the tumours of more than 90% of those people with glioblastoma whom they examined, but not in healthy brain tissue, nor in non-m alignant brain tumours. They then began an experiment on 21 patients who had been diagnosed with glioblastoma.The results are encouraging. The normal prognosis for glioblastoma is death within two years, even if a patient is treated with chemotherapy and radiation. Such treatment by itself is reckoned to slow the tumour’s growth by between six and eight months. When Dr Mitchell added his crude vaccine to the traditional treatment, this figure rose to more than a year—and in some people the tumours have stopped growing for more than two years, an observation that opens the door to work on a proper vaccine.Just why active cytomegalovirus is associated with glioblastoma is still unclear. The...