GTPase Rap1 contribution to tumor development

Abstract

The currently available anti-cancer treatments are most effective when a patient is diagnosed with cancer before metastatic formation. To prevent metastatic formation it is important to know the signaling mechanisms that regulate the tumor migration. The small GTPase Rap1 is a molecular switch involved in the metastatic formation of various tumor types. Therefore it is important to understand it signaling mechanism because when its signaling pathway is better understood it might help to develop new anti-cancer treatments. Rap1 is involved in several steps of tumor development which makes it difficult to study and understand its signaling mechanism. For example Rap1 is involved in tumor migration by regulating the cytoskeleton and the activation of integrins and cadherins. Rap1 is also involved in the activation of the MAPK/ERK pathway, regulating cell migration and proliferation. Because Rap1 is involved in several steps of the tumor development it is difficult to find anti-cancer treatments to the effects of Rap1. But there are already some potential drug targets suggested such as JAM-A, an adhesion protein, for breast cancer treatment. A B-Raf kinase inhibitor has been shown to also decrease tumor development and integrin inhibitors have already been studied in preclinical trails as potential anti-cancer drugs. This review will give an overview on what is known about the Rap1 signaling pathways and involvement in tumor development. Finally some potential anti-cancer drug targets will be discussed.