Studies On The Role Of PEBP4 In Development Of Diethyl Nitrosamine(DEN)-Induced Primary Liver Cancer And The Underlying Mechanism

Objectives:Primary liver cancer is a common malignant tumor in clinic,Due to difficulty in early diagnosis and easy to be overlooked,most cases have advanced to metastasis at the time of diagnosis,resulting in reduced survival rate pessimistic outcomes,The disease seriously endangers the life and health of patients.The project aims to use PEBP4 knockout mice to construct a liver cancer model to explore the effect and molecular mechanism of phosphatidylethanolamine-binding protein 4（PEBP4）in the occurrence of liver cancer,so as to provide a new theoretical clue and practical guidance for clinical treatment.Methods:Liver cancer model was constructed by treatment of mice with DEN.Thus,the following groups were divided: PEBP4^+/+ mice administered with PBS,PEBP4^+/+mice with DEN,PEBP4^-/-mice with PBS and PEBP4^-/-mice with DEN.The effect of PEBP4 on the occurrence of liver cancer was observed by gross morphology,H&E staining and IHC.Western-blot was employed to detect the effect of PEBP4 on Akt/mTOR signaling pathway related indexes,and co-immunoprecipitation to examine association between PEBP4 and Akt/mTOR.Result:1.Compared with PEBP4^-/-,the number of DEN-induced tumors was significantly increased in PEBP4^+/+ mice（^*P<0.05）.Furthermore,H&E staining results showed that the liver tumor boundaries of DEN-induced PEBP4^+/+ group were clear and cancer cells were arranged in beams or clumps,and immunohistochemical analysis indicated that the ability of cell proliferation was enhanced in liver cancer tissue.2.After knocking out PEBP4,Activation of p-Akt and p-mTOR in DEN-induced PEBP4^-/-mice were significantly reduced（^*P<0.05）,and p-RSK2,p-S6,p-SGK1 and p-PKCα were also significantly reduced（^*P<0.05）as compared with DENinduced PEBP4^+/+ mice.3.PEBP4 was found to stabilize the complex containing Akt and mTOR.While cell experiments further suggested the association between PEBP4 and mTOR was mediated by Akt.Conclusion:1.Preliminarily shown that PEBP4 plays an important role in promoting the development of liver cancer.2.The role of PEBP4 in the development of liver cancer may be mediated by the direct interaction between PEBP4 and Akt/mTOR,leading to activation of the downstream signaling pathway.