Figure 5.

A schematic diagram illustrating miR-185 and ATR function in radiation response. ATR is activated by DNA damage resulting from exposure to ionizing radiation in combination with a series proteins such as replication protein A (RPA), ATR-interacting protein (ATRIP), DNA topoisomerase II-binding protein 1 (TOPBP1), RAD17 and the 9-1-1 complex (Flynn and Zou³⁰). Activated ATR phosphorylates its effector kinase Chk1. Consequently, the ATR-Chk1 pathway has an important role in detecting DNA damage, initiating DNA repair and coordinating with other cellular processes, and serves as a central safeguard of the genome. However, elevation of miR-185 represses the ATR-Chk1 pathway and sensitizes cancer cells to ionizing radiation by promoting apoptosis and inhibition of proliferation