Midkine promotes hepatocellular carcinoma metastasis by elevating anoikis resistance of circulating tumor cells

• Published in: Oncotarget Vol. 8; no. 20; pp. 32523 - 32535
• Main Authors: Sun, Bin, Hu, Congli, Yang, Zhibin, Zhang, Xiaofeng, Zhao, Linlin, Xiong, Junye, Ma, Junyong, Chen, Lei, Qian, Haihua, Luo, Xiangji, Shi, Lehua, Li, Jun, Cheng, Xianshuo, Yin, Zhengfeng
• Format: Journal Article
• Language: English
• Published: United States Impact Journals LLC 16-05-2017
• Subjects: Animals; Anoikis - genetics; Carcinoma, Hepatocellular - genetics; Carcinoma, Hepatocellular - pathology; Cytokines - metabolism; Disease Progression; Female; Humans; Liver Neoplasms - genetics; Liver Neoplasms - pathology; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Metastasis; Neoplastic Cells, Circulating - pathology; Research Paper; midkine; circulating tumor cells; anoikis resistance; hepatocellular carcinoma
• ISSN: 1949-2553; 1949-2553
• DOI: 10.18632/oncotarget.15808

Midkine is overexpressed in hepatocellular carcinoma (HCC) and plays a role in tumor progression, but less is known about its role in resistance of circulating tumor cells (CTCs) to anoikis which leading to recurrence and metastasis. The aim of the present study was to analyze whether midkine was associated with HCC progression with anoikis resistance. We found that cultured HCC cells were more resistant to anoikis, which paralleled midkine expression, and midkine treatment significantly inhibited anoikis in a dose-dependent manner. Furthermore, in in vitro and in vivo assays, knockdown of midkine resulted in significant sensitivity to anoikis, decreased cell survival and significantly decreased tumor occurrence rate. Patients with midkine-elevated HCC had higher CTC counts and less apoptotic CTCs, as well as significantly higher recurrence rate and shorter recurrence-free interval. To understand the molecular mechanism underlying the midkine with HCC progression, we performed in vitro and in vivo studies. We found that midkine plays an important role in enhancement of HCC cell resistance to anoikis, thereby promoting subsequent metastasis. Activation of PI3K/Akt/NF-κB/TrkB signaling by midkine-activated anaplastic lymphomakinase (ALK) is responsible for anoikis resistance.