299 - Identification of TRMT10C as a ROS Sensor Protein of Hepatocellular Carcinoma

Abstract

Reactive oxygen species (ROS) is one of the major cause of HCC (Hepatocellular carcinoma). During the development process from early grade to advanced grade of HCC, it is well known that ROS resistance, a trait of liver cancer cells, is acquired. It is also well known that ROS levels increase during liver cancer development. The increased concentration ROS up-regulates expression levels or activities of tumor-promoting proteins. Cysteine modifications are caused by redox signal or oxidative stress with the representative example being the modification by disulfide bond. We found the protein essential for inducing ROS resistance using LC-MS/MS method. ROS induces cysteine modification of the TRMT10C protein in liver cancer cell lines. The monolith-based analysis and MTT assay also showed that ROS was associated with our ROS-sensitive candidates. After treatment of 300uM ROS, we detected intracellular ROS level of wild-type TRMT10C and (C123S) cysteine mutant overexpression in HCC cell lines using H2DCFDA assay and total gultathion detect assay. Finally, after treatment of ROS, we determined the functional cysteine required for the formation of disulfide bond involved in the oxidative protein folding process using 1D, 2D gel electrophoresis after DTT treatment. Taken together, we expected that analyses based on our ROS-sensitive candidates will aid in better understanding the development of liver cancer.