Potential lncRNA diagnostic biomarkers for early gastric cancer.

Long noncoding RNAs (lncRNAs) serve important functions in many crucial biological processes; however, the effects of lncRNAs in early gastric cancer (EGC) are not entirely clear. The present study aimed to demonstrate the potential of lncRNAs to be used as biomarkers in EGC. Reverse transcription‑quantitative polymerase chain reaction was used to measure the expression levels of lncRNAs, including X inactive‑specific transcript (XIST), Yiya, brain cytoplasmic RNA 1 (BCYRN1), ribosomal RNA processing 1B (RRP1B), KCNQ1 opposite transcript 1 (KCNQ1OT1) and testes development related 1 (TDRG1), in EGC tissues compared with normal adjacent tissues (NATs). XIST, BCYRN1, RRP1B and TDRG1 were identified as differentially expressed in EGC tissues compared with NATs. The specificity and sensitivity of XIST, BCYRN1, RRP1B and TDRG1 were determined by receiver operating characteristic curve analysis. In addition, RRP1B expression was revealed to be significantly correlated with distal metastasis (P=0.020) and tumor‑node‑metastasis staging (P=0.018), and TDRG1 expression was significantly correlated with lymph node metastasis (P=0.001). Furthermore, BCYRN1, RRP1B and TDRG1 expression levels were compared between EGC tissues and plasma, and the results indicated that there were significant positive correlations of XIST, BCYRN1, RRP1B and TDRG1 expression levels between the EGC tissues and plasma. Therefore, the present study suggested that XIST, BCYRN1, RRP1B and TDRG1 may be served as potential diagnostic biomarkers for EGC.