Linc-ROR and its spliced variants 2 and 4 are significantly up-regulated in esophageal squamous cell carcinoma

OBJECTIVES Similar characteristics of molecular pathways between cellular reprogramming events and tumorigenesis have been accentuated in recent years. Reprogramming-related transcription factors, also known as Yamanaka factors (OCT4, SOX2, KLF4, and c-MYC), are also well-known oncogenes promoting cancer initiation, progression, and cellular transformation into cancer stem cells. Long non-coding RNAs (lncRNAs) are a major class of RNA molecules with emerging roles in stem cell pluripotency, cellular reprogramming, cellular transformation, and tumorigenesis. The long intergenic non-coding RNA ROR (lincRNA-ROR, linc-ROR) acts as a regulator of cellular reprograming through sponging miR-145 that normally negatively regulates the expression of the stemness factors NANOG, OCT4, and SOX2. MATERIALS AND METHODS Here, we employed a real-time PCR approach to determine the expression patterns of linc-ROR and its two novel spliced variants (variants 2 and 4) in esophageal squamous cell carcinoma (ESCC). RESULTS The quantitative real-time RT-PCR results revealed a significant up-regulation of linc-ROR (P=0.0098) and its variants 2 (P=0.0250) and 4 (P=0.0002) in tumor samples of ESCC, compared to their matched non-tumor tissues obtained from the margin of same tumors. Our data also demonstrated a significant up-regulation of variant 4 in high-grade tumor samples, in comparison to the low-grade ones (P=0.04). Moreover, the ROC curve analysis demonstrated that the variant 4 of ROR has a potential to discriminate between tumor and non-tumor samples (AUC=0.66, P<0.05). CONCLUSION Our data suggest a significant up-regulation of linc-ROR and its variants 2 and 4 in ESCC tissue samples.