Angiomotin promotes breast cancer cell proliferation and invasion

Angiomotin (Amot) is a multifunctional protein involved in endothelial cell migration and tube formation and angiogenesis. However, the biological role and molecular mechanism for the abnormal expression of Amot in breast cancer is poorly understood. The aim of the present study was to examine the function of and relationship between Amot and the Hippo-Yes-associated protein (YAP) pathway. The expression and location of Amot was examined in breast cancer tissues and cell lines using immunohistochemistry, real-time polymerase chain reaction analysis (RT-PCR), western blotting and immunofluorescence. ANOVA, Student's t-test, Wilcoxon and Chi-square tests were utilized to determine the association of Amot expression with clinically relevant parameters. Stable Amot knockdown MCF-7 cells (MCF-7 Amot KD) were generated to investigate the impact of Amot downregulation on the growth and invasion of MCF-7 cells in vitro. Western blotting was applied to detect the expression of the Hippo-YAP pathway protein in the MCF-7 cells. It was observed that Amot was highly expressed in breast cancer tissues, but weakly expressed in adjacent non-cancerous tissues. Additionally, the expression level of Amot was correlated with that of Ki-67. In MCF-7 cells, Amot downregulation resulted in a significant decrease of cell proliferation and invasiveness. Following Amot knockdown in MCF-7 cells, the expression of YAP, YAP/TAZ and LATS1 was decreased. In particular, the expression of YAP was markedly reduced in the nucleoprotein. The results suggested that Amot was highly expressed in breast cancer tissues and was important in the promotion of breast cancer cell proliferation and invasion. In addition, there was a more intimate connection between Amot and Hippo-YAP pathway.