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

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.

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.

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.

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