Abstract
OBJECTIVES: To investigate the clinical significance of abnormal expression of angio-associated migratory cell protein (AAMP) in hepatocellular carcinoma (HCC). METHODS: Bioinformatics analyses were used to analyze AAMP expression level in HCC and its prognosis value. In 60 pairs of HCC and adjacent tissues, AAMP expression was detected immunohistochemically and its correlation with clinicopathological characteristics of the patients was analyzed. In cultured Mahlavu and Huh-7 cells with lentivirus-mediated AAMP knockdown, the changes in cell proliferation, apoptosis, migration and invasion were observed, and their lung metastasis following tail vein injection in nude mice were assessed. In HCC cells with AAMP knockdown, Western blotting, immunofluorescence staining or RT-qPCR were used to examine the changes in expression levels of E-cadherin, N-cadherin, Vimentin and Snail and the effects of MG-132 and CHX on RhoA expression. The correlation between the expressions of AAMP and RhoA in HCC tissues was analyzed by immunohistochemistry. RESULTS: Bioinformatics analysis showed that AAMP expression was elevated in HCC tissues (P<0.05) in correlation with advanced clinical stage and poor prognosis (P<0.05). Immunohistochemistry results confirmed significant correlations of high AAMP expression with Edmondson-Steiner grade (III+IV), venous infiltration and TNM stage (III+IV) of HCC (P<0.05). In cultured HCC cells, AAMP knockdown did not significantly affect cell proliferation or apoptosis, but obviously suppressed cell migration and invasion in vitro and lung metastasis in nude mice. AAMP knockdown significantly increased E-cadherin expression, decreased N-cadherin, Vimentin and Snail expressions, and reduced RhoA protein levels without obviously affecting RhoA mRNA levels. MG-132 treatment blocked the inhibitory effect of AAMP knockdown on RhoA protein expression. The expressions of AAMP and RhoA showed a significant positive correlation in HCC tissues (P<0.05). CONCLUSIONS: AAMP overexpression is associated with malignant clinical features of HCC and promotes epithelial-mesenchymal transition and metastasis of HCC cells partly by stabilizing RhoA expression.