Mitogen-activated protein kinase kinase kinase 4 deficiency in intrahepatic cholangiocarcinoma leads to invasive growth and epithelial-mesenchymal transition.
The molecular pathogenesis of intrahepatic cholangiocarcinoma (iCCA) is poorly understood, and its incidence continues to increase worldwide. Deficiency of mitogen-activated protein kinase kinase kinase 4 (MAP3K4) has been reported to induce the epithelial-mesenchymal transition (EMT) process of placental and embryonic development, yet its role in human cancer remains unknown. MAP3K4 has somatic mutation in iCCA so we sequenced all exons of MAP3K4 in 124 iCCA patients. We identified nine somatic mutations in 10 (8.06%) patients, especially in those with lymph node metastasis and intrahepatic metastasis. We also showed that messenger RNA and protein levels of MAP3K4 were significantly reduced in iCCA versus paired nontumor tissues. Furthermore, knockdown of MAP3K4 in cholangiocarcinoma cells markedly enhanced cell proliferation and invasiveness in vitro and tumor progression in vivo, accompanied by a typical EMT process. In contrast, overexpression of MAP3K4 in cholangiocarcinoma cells obviously reversed EMT and inhibited cell invasion. Mechanistically, MAP3K4 functioned as a negative regulator of EMT in iCCA by antagonizing the activity of the p38/nuclear factor κB/snail pathway. We found that the tumor-inhibitory effect of MAP3K4 was abolished by inactivating mutations. Clinically, a tissue microarray study containing 322 iCCA samples from patients revealed that low MAP3K4 expression in iCCA positively correlated with aggressive tumor characteristics, such as vascular invasion and intrahepatic or lymph node metastases, and was independently associated with poor survival and increased recurrence after curative surgery.


CONCLUSIONS
MAP3K4, significantly down-regulated, frequently mutated, and potently regulating the EMT process in iCCA, was a putative tumor suppressor of iCCA.
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Liu-Xiao
LX
Yang
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Qiang
Q
Gao
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Jie-Yi
JY
Shi
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Zhi-Chao
ZC
Wang
Department of General Surgery, Zhongshang Hospital (South), Fudan University, Shanghai, P.R. China.
Yong
Y
Zhang
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Ping-Ting
PT
Gao
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Xiao-Ying
XY
Wang
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Ying-Hong
YH
Shi
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Ai-Wu
AW
Ke
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Guo-Ming
GM
Shi
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Jia-Bin
JB
Cai
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Wei-Ren
WR
Liu
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Meng
M
Duan
Department of Medical Oncology, Fudan University Shanghai Cancer Center, and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.
Ying-Jun
YJ
Zhao
Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China.
Yuan
Y
Ji
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Dong-Mei
DM
Gao
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Kai
K
Zhu
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.|Institute of Biomedical Sciences, Fudan University, Shanghai, P.R. China.
Jian
J
Zhou
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.
Shuang-Jian
SJ
Qiu
Cancer Research Institute, Xiangya School of Medicine, Central South University, Hunan, P.R. China.
Ya
Y
Cao
Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai, P.R. China.
Qi-Qun
QQ
Tang
Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai, P.R. China.|Institute of Biomedical Sciences, Fudan University, Shanghai, P.R. China.
Jia
J
Fan
D001650:Bile Duct Neoplasms / Q000201:enzymology* / Q000473:pathology*; D018281:Cholangiocarcinoma / Q000201:enzymology* / Q000473:pathology*; D058750:Epithelial-Mesenchymal Transition; D006801:Humans; D048768:MAP Kinase Kinase Kinase 4 / Q000172:deficiency*; D009361:Neoplasm Invasiveness
D048768:MAP Kinase Kinase Kinase 4