Circulatinglong non-coding RNA FEZF1-AS1 and AFAP1-AS1 serve as potential diagnostic biomarkers for gastric cancer

Background: Growing evidence indicates that two long non-coding RNAs (lncRNAs), FEZ family zinc finger 1 antisense RNA 1 (FEZF1-AS1) and Actin filament associated protein 1 antisenseRNA1 (AFAP1-AS1), are highly expressed in different cancers, including gastric cancer (GC). However, the expression pattern and clinical utility of these two lncRNAs are still unknown.

Methods: Serum expression levels of FEZF1-AS1 andAFAP1-AS1 were measured by quantitative real-time polymerase chain reaction (qRT-PCR). CEA and CA19-9 were detected by ARCHITET I2000 SR. Analyses were all performed using SPSS software version 20.0 (SPSS Inc., Chicago, USA). P < 0.05 was considered statistically significant.

Results: Detection of serum FEZF1-AS1 and AFAP1-AS1 showed both of them were up-regulated in GC patients compared with the normal controls (p < 0.0001), and high serum expression levels were correlated with tumor size, tumor-node-metastasis (TNM) stage and lymph node metastasis. Besides, the area under the ROC curve (AUC) demonstrated the two lncRNAs had higher diagnostic utility than CEA and CA19-9. Furthermore, when combined the two lncRNAs as a model, it yielded an AUC of 0.866, and the combination of the model, CEA and CA19-9 could observably improve diagnostic sensitivity to 95.5 %. What's more, circulating FEZF1-AS1 and AFAP1-AS1 were significantly decreased after the GC patients underwent the operation (both p < 0.001).

Conclusion: Our study indicated that serum FEZF1-AS1 and AFAP1-AS1 had better sensitivity and efficiency for the diagnosis of GC and the combination of the two lncRNAs might be used as a potential prognostic indicator in GC.