ULK1 Depletion Protects Mice from Diethylnitrosamine-Induced Hepatocarcinogenesis by Promoting Apoptosis and Inhibiting Autophagy

Abstract

Ting Duan,1,2,* Xin Yang,3,* Jingyu Kuang,4 Wenjie Sun,3 Jin Li,3 Juan Ge,3 Mohan Zhang,3 Xiaobo Cai,3 Peilin Yu,3 Jun Yang,5 Xinqiang Zhu6 1School of Pharmacy, Hangzhou Normal University, Hangzhou, 311121, People’s Republic of China; 2Key Laboratory of Elemene Class Anti-Cancer Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, School of Pharmacy, Hangzhou Normal University, Hangzhou, 311121, People’s Republic of China; 3Department of Toxicology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, People’s Republic of China; 4Department of Biology and Chemistry, College of Sciences, National University of Defense Technology, Changsha, Hunan, 410073, People’s Republic of China; 5Department of Nutrition and Toxicology, Hangzhou Normal University School of Public Health, Hangzhou, Zhejiang, 311121, People’s Republic of China; 6Medical Research Center, The Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, 322000, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xinqiang Zhu; Jun Yang, Email [email protected]; [email protected]: The uncoordinated-51 like kinase 1 (ULK1) is an important serine/threonine protein kinase involved in autophagy, especially for the initiation stage. Previous studies have shown that ULK1 could be used as a prognostic marker in predicting poor progression-free survival and a therapeutic target for hepatocellular carcinoma (HCC) when treated with sorafenib; however, its role during hepatocarcinogenesis remains to be elucidated.Methods: CCK8 and colony formation assay were used to detect cell growth ability. Western blotting was performed to determine expression level of protein. Data from public database were downloaded to analyze expression of ULK1 at mRNA level and predict survival time. RNA-seq was conducted to reveal disturbed gene profile orchestrated by ULK1 depletion. A diethylnitrosamine (DEN)-induced HCC mice model was used to uncover the role of ULK1 in hepatocarcinogenesis.Results: ULK1 was up-regulated in liver cancer tissues and cell lines, and knockdown of ULK1 promoted apoptosis and suppressed proliferation of liver cancer cells. In in vivo experiments, Ulk1 depletion attenuated starvation-induced autophagy in mice liver, reduced diethylnitrosamine (DEN)-induced hepatic tumor number and size, and prevented tumor progression. Further, RNA-seq analysis revealed a close relationship between Ulk1 and immunity with significant changes in gene sets enriched in the interleukin and interferon pathways.Conclusion: ULK1 deficiency prevented hepatocarcinogenesis and inhibited hepatic tumor growth, and might be a molecular target for the prevention and treatment of HCC.Keywords: hepatocellular carcinoma, ULK1, RNA-sequencing, apoptosis, autophagy

Keywords

• hepatocellular carcinoma
• ulk1
• rna-sequencing
• apoptosis
• autophagy