An experimental drug has switched off a gene linked to an aggressive and incurable type of brain cancer and extended the lives of mice.
The brain cancer, glioblastoma multiforme, kills about 13 000 Americans a year and is the form of the disease that led to Senator Edward Kennedy's death in 2009.
The drug used in the study is based on nanotechnology and is small enough to cross the blood-brain barrier to get to brain tumours. It targets and turns off a specific cancer-causing gene in cells. Silencing the gene eliminates proteins that prevent cancer cells from dying.
The mice received the drug via intravenous injection, and lived nearly 20% longer. Their tumours were three to four times smaller, according to the study, which was published in the journal Science Translational Medicine.
"This is a beautiful marriage of a new technology with the genes of a terrible disease," said study senior co-author and nanomedicine expert Chad Mirkin, a professor of chemistry and medicine at Northwestern University.
Study senior co-author Alexander Stegh said: "Glioblastoma is a very challenging cancer and most chemo-therapeutic drugs fail in the clinic.
"The beauty of the gene we silenced in this study is that it plays many different roles in therapy resistance," said Stegh, an assistant professor in the neurology department at the Northwestern University Feinberg School of Medicine and an investigator at the Northwestern Brain Tumour Institute.
"Taking the gene out of the picture should allow conventional therapies to be more effective."
The next step is to test the drug in clinical trials. Experts note that results achieved in animal studies often don't translate to humans.
About 16 000 new cases of glioblastoma multiforme are diagnosed in the United States each year. The average survival is 14 to 16 months.
The American Brain Tumour Association has more about glioblastoma tumours.