August 10, 2011

Development in Anti-tumor Drugs

(Ivanhoe Newswire)--Researchers are gaining insight on how to slow the growth of tumors via angiogenesis inhibitors. Angiogenesis is the process involving the growth of new blood vessels from pre-existing ones. This is a normal process for growth and development as well as wound healing. Angiogenesis has also been proven to be a fundamental step in transitioning tumors from a dormant state to a malignant one which leads to the use of inhibitors which eliminate blood supply to these tumors.

Investigators from the Semmelweis University, the National Institute of Oncology, the National Koranyi Institute of Pulmonology in Budapest, Hungary, and the Medical University of Vienna in Vienna, Austria examined tumor tissue of mice in which malignant tumor cells were introduced. They noticed a significant increase in tissue pillar formation after treatment with angiogenesis inhibitor vatalanib.

Their observations support the idea that the inhibition of just one tumor vascularization mechanism can trigger others. This investigation creates a connection between the processes of endothelial bridging and intussusceptive angiogenesis, often referred to as splitting angiogenesis, resulting in rapid pillar formation from pre-existing building blocks.   The observations from this study suggest that targeting this method of blood vessel formation may not be enough to significantly reduce tumor effects.

Lead investigators of the study, Sandor Paku, Ph.D., at Semmelweis University in Budapest and Balaza Dome, M.D., Ph.D., at the Medical University of Vienna were quoted saying, "It is well established now that tumors can obtain sufficient blood supply from alternative vascularization mechanisms (such as intussusceptive angiogenesis) to grow without capillary sprouting (known as the key mode of new vessel formation in cancer.) Therefore, antiangiogenic therapies should be tailored depending on the angiogenic phenotype in each single tumor, and the targeting of non-sprouting angiogenic mechanisms in cancer seems to be a rational strategy. Our study provides new understanding of cancer-induced intussusceptive angiogenesis and may serve as a basis for the development of novel drugs targeting this type of blood vessel formation."

SOURCE: The American Journal of Pathology; August 10, 2011