Aberrant expression of translationally controlled tumor protein (TCTP) can lead to radioactive susceptibility and chemosensitivity in lung cancer cells

// Jiahui Du 1 , Peng Yang 1 , Fanhua Kong 2 and Haiyan Liu 3 1 Department of Thoracic Surgery, Linyi People’s Hospital, Linyi, Shandong 276000, China 2 Department of Thoracic Surgery, Taian City Central Hospital, Taian, Shandong 271000, China 3 Department of Nursing, Linyi People’s Hospital, Linyi 276000, China Correspondence to: Haiyan Liu, email: HaiyanLiulinyi123@163.com Keywords: lung cancer; translationally controlled tumor protein; apoptosis; P53 Abbreviations: lTCTP: translationally controlled tumor protein; ActD: actinomycin D; KD: knockdown Received: May 24, 2017 Accepted: July 29, 2017 Published: October 10, 2017 ABSTRACT Translationally controlled tumor protein (TCTP) is an evolutionally highly conserved protein which has been implicated as a biomarker for cancer cell reversion although the mechanism is not very clear. This makes it a potential target for cancer therapy. P53 tumor suppressor protein is important in regulating cell growth, it can induce either growth arrest or programmed cell death (apoptosis). TCTP and P53 has been reported that can regulate the protein level of each other. Here we proved that TCTP is a malignancy state keeper in lung cancer and lower level of TCTP protein made cells more sensitive to stressful condition. No obvious difference has been observed from wildtype and the TCTP knockdown lung cancer cells (A549) when located in the normal circumstances. While under the stressful condition, the existence of higher protein level of TCTP can protect cells from apoptosis. TCTP and P53 formed a feedback signal pathway and through it to regulate the downstream Akt signal pathways to make the lung cancer cells keep a higher metabolism level and protect cancer cells from apoptosis induced by outside stress.