Down-regulation of long non-coding RNA LET is associated with poor prognosis in gastric cancer.

Introduction: Long non-coding RNAs (lncRNAs) have emerged recently as major players in tumor biology and may be used for cancer diagnosis, prognosis, and potential therapeutic targets. Although down-regulation of lncRNA LET in several cancers has been studied, its role in gastric cancer remains unknown. The aim of our study was to investigate the expression, and clinical significance of lncRNA LET in gastric cancer.

Methods: The expression of lncRNA LET was detected by quantitative real-time PCR (qRT-PCR) in pairs of tumor tissues and adjacent non-tumor tissues of 93 gastric cancer patients. Then, we analyzed the potential relationship between lncRNA LET expression levels in tumor tissues and clinicopathological features of gastric cancer, and clinical outcome.

Results: We found that lncRNA LET expression was markedly down-regulated in tumor tissues compared with adjacent non-tumor tissues, and associated with depth of invasion, lymph node metastasis, distant metastasis, and TNM stage. Kaplan-Meier analysis showed that patients with low lncRNA LET expression had a poor overall survival than those with high lncRNA LET expression. Moreover, univariate and multivariate analyses showed that low lncRNA LET expression was an independent poor prognostic factor for gastric cancer patients.

Conclusions: Our data provided the first evidence that lncRNA LET might be a novel prognostic indicator in gastric cancer and might be a potential target for diagnosis and gene therapy.