Autocrine stimulation of mas oncogene leads to altered growth control

Mas oncogene has been shown to have focus-inducing ability in NIH 3T3 cells which are tumorigenic in vivo in nude mice. Its stable expression in a variety of cell lines conferred some angiotensin responsiveness. To understand why mas-transfected cells exhibit a transformed phenotype and if angiotensin responsiveness plays any role in this process, we studied the growth characteristics of mas-transfected 3T3 cells and demonstrated that they lose contact inhibition, exhibit foci formation, and increased DNA synthesis even in absence of serum. Our results suggest that the transformed phenotype is due to the production of a mas receptor ligand distinct from angiotensin.