A-kinase-interacting protein 1 facilitates growth and metastasis of gastric cancer cells via Slug-induced epithelial-mesenchymal transition.

A-kinase-interacting protein 1 (AKIP1) has previously been reported to act as a potential oncogenic protein in various cancers. The clinical significance and biological role of AKIP1 in gastric cancer (GC) is, however, still elusive. Herein, this study aimed to investigate the functional and molecular mechanism by which AKIP1 influences GC. AKIP1 mRNA and protein expressions in GC tissues were examined by quantitative real-time PCR (qRT-PCR), Western blot and immunohistochemistry. Other methods including stably transfected against AKIP1 into gastric cancer cells, wound healing, transwell assays, CCK-8, colony formation, qRT-PCR and Western blot in vitro and tumorigenesis in vivo were also performed. The up-regulated expression of AKIP1 in GC specimens significantly correlated with clinical metastasis and poor prognosis in patients with GC. AKIP1 knockdown markedly suppressed GC cells proliferation, invasion and metastasis both in vitro and in vivo. In contrast, AKIP1 overexpression resulted in the opposite effects. Moreover, mechanistic analyses indicated that Slug-induced epithelial-mesenchymal transition (EMT) might be responsible for AKIP1-influenced GC cells behaviour. Our findings demonstrated that high AKIP1 expression significantly correlated with clinical metastasis and unfavourable prognosis in patients with GC. Additionally, AKIP1 promoted GC cells proliferation, migration and invasion by activating Slug-induced EMT.