A gene therapy that prevents tumour cells from growing in mice could one day offer hope to sufferers of hard-to-treat pancreatic cancer, new research suggests.
Pancreatic cancer is the fifth-leading cause of cancer deaths in the West and is virtually untreatable – only 3% of patients are alive five years after diagnosis. Most die within six months of diagnosis, since symptoms do not usually appear until the cancer is very advanced.
Researchers at Shanghai Second Medical University in China researched a human protein called vasostatin, which studies have shown suppresses the development of new blood vessels. Tumour cells – particularly solid tumours such as pancreatic tumours – are heavily dependent on a good blood supply to enable them to grow.
Once they reach a size of 2 cubic millimetres, tumours need to develop their own blood vessels – a process known as angiogenesis – to ensure a constant supply of the nutrients needed for rapid malignant cell growth.
Reduced proliferation
Yao-Zong Yuan and colleagues used a stripped-down virus that was genetically modified to carry the vasostatin gene and could penetrate tumour cells. They took a group of mice that had human pancreatic tumour cells grafted onto their flanks and infected them with the GM virus.
After 72 hours, there was significant tumour growth in a control group of mice that had not received the injection, whereas tumour growth had been curbed in the treated mice.
Following seven rounds of the therapy, the researchers found that although vasostatin appeared to have little impact on existing pancreatic cells, their proliferation was greatly reduced and angiogenesis had been significantly inhibited.
The method “may be a potent strategy to treat many malignant tumours, including pancreatic cancer, and represents a promising therapeutic option for malignancy with a poor prognosis”, the researchers write.
Journal reference: Gut (DOI: 10.1136/gut.2005.064980)
