Washington, Apr 24 : Researchers at Lineberger Comprehensive Cancer Center at the University of North Carolina at Chapel Hill, have identified new cell targets for preventing the development of breast cancer tumours and other tumours by blocking angiogenesis-a vital step in tumour progression.
Angiogenesis, simply the formation of blood vessels, plays an important role in the growth and spread of cancer, as new blood vessels provide essential nourishment to cancer cells, allowing them to grow, travel to other parts of the body and form new cancers.
According to the researchers, targeting angiogenesis is certainly less toxic than the standard chemotherapy approach that kills cancer cells and normal cells in the same way.
Other researchers have also shown that this new tactic shows positive results in the treatment of breast cancer and colon cancer with the drug bevacizumab (commercially known as Avastin), by inhibiting an important protein in angiogenesis, called vascular endothelial growth factor (VEGF).
"There is a large amount of data that shows if you block angiogenesis, you can block tumor growth. But VEGF is not responsible for all of angiogenesis. We wanted to identify more targets for this therapeutic approach. The most exciting aspect of this study is that we now have a very large list of potential targets that we will continue to work on for at least the next decade," said Dr. Nancy Klauber-DeMore, associate professor of surgery in the UNC School of Medicine.
As tumors cannot proliferate without the formation of new blood vessels, the researchers looked for new targets that are overexpressed on tumor blood vessels. After 3 years the researchers perfected a technique enabling them to microdissect individual vascular cells from frozen sections of five cancerous and five normal breast tissue samples.
After comparing the gene activity in both samples, they found 55 genes out of 1,176 were overexpressed more than four-fold in blood vessels from breast cancer.
They also found that seven of the genes encoded membrane or secreted proteins and four of these - namely FAP, SFRP2, JAK3 and SMPD3 - had not just increased gene expression, but also increased protein expression in breast tumor vessels, and thus could be good targets for the development of novel cancer therapies.
Klauber-DeMore said that there's a need for further research to accurately define whether these proteins induce angiogenesis which would then lead them to design new compounds and test existing ones to see if they inhibit tumor growth.
"We've only looked at seven out of a list of 55 potential targets. This work points us in the direction we need to go to develop the next generation of angiogenesis inhibitors," said Klauber-DeMore.
A report of the study appeared online in the American Journal of Pathology and will soon appear in the print edition of the journal.