KCS

The majority of endogenous reactive oxygen species (ROS) are produced in the mitochondrial respiratory chain, and an imbalance in ROS production alters the intracellular redox homeostasis, triggers DNA damage, and contributes to cancer development and progression. This study identified a novel protein, reactive oxygen species modulator 1 (Romo1), which is localized in mitochondria. Romo1 was found to increase the level of ROS in the cells, and induce nuclear DNA damage. Increased Romo1 expression was observed in various cancer cell lines and tumor tissues. The exogenous expression of Romo1 augmented the transforming activity of the oncogenic H-Ras in an in vitro transformation experiment even though Romo1 itself does not show transforming activity. These results suggest that the increased Romo1 expression during cancer progression may cause persistent oxidative stress to tumor cells, which can make some of them more malignant. Romo1 is a new promising target for the development of novel drugs aimed at cancer and other diseases.