Feng Xiao-Jun, Pan Qing, Wang Shou-Mei, Pan Yun-Cui, Wang Qian, Zhang Huan-Huan, Zhu Ming-Hua, Zhang Shu-Hui
Department of Pathology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Changxing Chinese medicine hospital, Huzhou, Zhejiang Province, China.
Tumour Biol. 2016 Aug;37(8):11457-67. doi: 10.1007/s13277-016-5022-1. Epub 2016 Mar 24.
Our previous study has reported that mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) regulates the growth and survival of hepatocellular carcinoma (HCC) cells. This study was undertaken to explore the roles of MAP4K4 in the epithelial-mesenchymal transition (EMT) and metastasis in HCC. Effects of overexpression and knockdown of MAP4K4 on the migration, invasion, and EMT of HCC cells were examined. The in vivo role of MAP4K4 in lung metastasis of HCC was determined in nude mice. The relationship between MAP4K4 expression and EMT in human HCC specimens was determined by immunohistochemistry. MAP4K4 overexpression significantly enhanced the migration and invasion of MHCC-97L HCC cells, whereas MAP4K4 silencing hindered the migration and invasion of MHCC-97H HCC cells. MAP4K4-overexpressing cells undergo EMT, which was accompanied by downregulation of E-cadherin and upregulation of vimentin. In contrast, MAP4K4 silencing caused a reversion from a spindle morphology to cobblestone-like morphology and induction of E-cadherin and reduction of vimentin. Pretreatment with chemical inhibitors of JNK and NF-κB abolished MAP4K4-mediated migration, invasion, and regulation of EMT markers in MHCC-97L cells. Ectopic expression of MAP4K4 promoted and knockdown of MAP4K4 inhibited lung metastasis of HCC, which was associated with regulation of JNK and NF-κB signaling and EMT markers. High MAP4K4 immunoreactivity was inversely correlated with E-cadherin and was positively correlated with vimentin, phospho-JNK, and phospho-NF-κB in HCC specimens. Taken together, MAP4K4 promotes the EMT and invasiveness of HCC cells largely via activation of JNK and NF-κB signaling.
我们之前的研究报道，丝裂原活化蛋白激酶激酶激酶激酶4（MAP4K4）调节肝细胞癌（HCC）细胞的生长和存活。本研究旨在探讨MAP4K4在HCC上皮-间质转化（EMT）和转移中的作用。检测了MAP4K4过表达和敲低对HCC细胞迁移、侵袭和EMT的影响。在裸鼠中确定了MAP4K4在HCC肺转移中的体内作用。通过免疫组织化学确定了MAP4K4表达与人类HCC标本中EMT的关系。MAP4K4过表达显著增强了MHCC-97L HCC细胞的迁移和侵袭，而MAP4K4沉默则阻碍了MHCC-97H HCC细胞的迁移和侵袭。过表达MAP4K4的细胞发生EMT，伴随着E-钙黏蛋白的下调和波形蛋白的上调。相反，MAP4K4沉默导致细胞从纺锤形形态转变为鹅卵石样形态，并诱导E-钙黏蛋白表达增加和波形蛋白表达减少。用JNK和NF-κB的化学抑制剂预处理消除了MAP4K4介导的MHCC-97L细胞的迁移、侵袭和EMT标志物调节。MAP4K4的异位表达促进了HCC的肺转移，而MAP4K4的敲低则抑制了肺转移，这与JNK和NF-κB信号通路及EMT标志物的调节有关。在HCC标本中，高MAP4K4免疫反应性与E-钙黏蛋白呈负相关，与波形蛋白、磷酸化JNK和磷酸化NF-κB呈正相关。综上所述，MAP4K4主要通过激活JNK和NF-κB信号通路促进HCC细胞的EMT和侵袭性。
