[Role of Abelson interactor 2 in progression and prognosis of gastric cancer and its regulatory mechanisms].

Objective: To explore the regulatory role of Abelson interactor 2 (ABI2) in progression and prognosis of gastric cancer.
Methods: TIMER2.0, GEPIA, Kaplan-Meier Plotter and DAVID databases were used to analyze ABI2 expression in pancancer and its association with the prognosis of gastric cancer. Gastric cancer and adjacent tissues from 120 patients undergoing radical gastrectomy in our hospital between January, 2016 and October, 2018 were examined for ABI2 expression and its correlation with disease progression and prognosis. MGC-803 cell models of ABI2 knockdown and overexpression were established for observing the changes in cell proliferation, migration, and invasion, and the impact of ABI2 expression modulation on xenograft growth was evaluated in nude mice.
Results: Database analysis and examination of the clinical samples showed that ABI2 was highly expressed in gastric cancer tissues. Survival analysis suggested that gastric cancer patients with a high expression of ABI2 had a reduced postoperative 5-year survival rate ( P < 0.0001), and further Cox univariate and multivariate survival analyses indicated that a high ABI2 expression was an independent risk factor affecting the patients survival outcomes ( P =0.022, HR =1.887, 95% CI : 1.096-3.249). Enrichment analysis suggested the involvement of ABI2 in Wnt signaling. In MGC-803 cells, ABI2 overexpression promoted cell proliferation and xenograft growth in nude mice, increased the expressions of vimentin and N-cadherin, and lowered E-cadherin expression, while ABI2 knockdown produced the opposite effects. Mechanistic analysis revealed that ABI2 overexpression promoted the expressions of Wnt2 and β-catenin in both MGC-803 cells and the xenografts, and their expressions were significantly lowered by ABI2 knockdown.
Conclusion: ABI2 is highly expressed in gastric cancer, which affects long-term prognosis of the patients, possible due to its regulatory effect on Wnt signaling to promote proliferation, migration and invasion of gastric cancer cells.