Pancreatic cancer is the fifth leading cause of cancer deaths in the developed world, and is extremely difficult to treat. Only 3% of affected patients are still alive five years after diagnosis, a survival rate that has remained static for the past three decades.
Currently, the only viable treatment is surgery. Radiotherapy and chemotherapy have little impact on the disease.
The research team investigated the potential of the protein vasostatin to suppress the development of new blood vessels and pancreatic tumour cells both in test tubes and in mice with pancreatic cancer.
'Solid' tumours, such as pancreatic cancer, are heavily dependent on a rich blood supply to enable them to grow rapidly and spread throughout the body. This process is known as angiogenesis.
The protein gene was incorporated into a virus (adenovirus), so that it would be able to penetrate the cells, acting as a vector.
The test tube experiments showed that 72 hours after infection with the genetically modified virus, vasostatin was clearly active in the tissue. Tumour growth in the mice was also curbed, and when compared with mice which had not been infected with the virus, the difference between the two groups was highly significant.
The researchers then looked more closely at the pancreatic cells and the cell linings of the blood vessels (vascular endothelial cells).
They found that although vasostatin seemed to have little impact on the pancreatic cells, it blocked the formation of new blood vessels, effectively cutting off the supply of nutrients to the malignant cells. This effect was seen in both the test tube and animal experiments.
This type of gene therapy "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," conclude the authors.
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