SPOP regulates the DNA damage response and lung adenocarcinoma cell response to radiation.

Speckle-type POZ protein (SPOP) plays an important role in maintaining genome stability. Disability or mutation of the SPOP gene has been reported to contribute to prostate cancer incidence and prognosis. However, the functions of SPOP in lung cancer remain poorly understood, especially in lung adenocarcinoma (LUAD). Here, we found that SPOP affects the LUAD cell response to radiation by regulating the DNA damage response (DDR) pathway. SPOP is widely expressed in lung cancer cell lines, and SPOP protein levels are upregulated when cells experience DNA damage. SPOP knockdown affects DDR repair kinetics, apoptosis and cell cycle checkpoints that are induced by IR (ionizing radiation). Furthermore, we found that SPOP positively regulates the expression of DDR factors Rad51 and Ku80. Taken together, these data indicate the essential roles of SPOP in the DDR signaling pathways and LUAD cell response to radiation.