Increased lncRNA AFAP1-AS1 expression predicts poor prognosis and promotes malignant phenotypes in gastric cancer.

Objective: The clinical significance and biological functions of long non-coding RNA AFAP1-AS1 in gastric cancer (GC) remain larger elucidated. The aim of the study is to investigate the role of lncRNA AFAP1-AS1 involved in GC progression.

Methods: Quantitative reverse transcription-polymerase chain reaction (QRT-PCR) assay was used to evaluate the expression of lncRNA AFAP1-AS1 in GC tissues, when compared with adjacent noncancerous tissues, respectively. Associations between lncRNA AFAP1-AS1 and the clinicopathological factors in GC patients were analyzed by X2-test. The prognostic significance was evaluated using Kaplan-Meier curve and Cox regression analysis. CCK8, flow cytometry analysis and transwell invasion assays were performed to assess cell proliferation and invasion abilities of GC.

Results: In this study, we verified that lncRNA AFAP1-AS1 expression was dramatically increased in GC tissues and cells, compared with noncancerous gastric tissues and control cells. The higher lncRNA AFAP1-AS1 expression was positively correlated with lymph node metastasis (p = 0.001), TNM stage (p = 0.006) and worse overall survival (OS) time in GC patients. Multivariate Cox analysis suggested that lymph node metastasis (Hazard ratio, HR = 2.966, p = 0.001), TNM stage (HR = 2.855, p = 0.001), and lncRNA AFAP1-AS1 expression levels (HR = 3.315, p = 0.001) were independent prognostic factors of OS in GC patients. Knockdown of lncRNA AFAP1-AS1 significantly inhibited the cell proliferation and cell cycle progression. Moreover, reduced lncRNA AFAP1-AS1 also inhibited the cell invasion ability via regulating cell epithelial-mesenchymal transition (EMT) phenomenon in GC.

Conclusions: These results demonstrated that lncRNA AFAP1-AS1 may be a potential therapeutic target for GC.