Differential Expression of Long Noncoding RNA in Primary and Recurrent Nasopharyngeal Carcinoma

Background. Recent studies suggested that non-protein-coding genes are implicated in the tumorigenic process of nasopharyngeal carcinoma (NPC). In the present study, we aimed to identify the differentially expressed long noncoding RNA (lncRNA) using data available in the public domain. Methods. Microarray data set GSE12452 was reannotated with ncFANs. Real-time quantitative PCR was used to quantify and validate the identified lncRNAs in NPC. Results. In primary NPC, upregulation of lnc-C22orf32-1, lnc-AL355149.1-1, and lnc-ZNF674-1 was observed. High levels of lnc-C22orf32-1 and lnc-AL355149.1-1 were significantly associated with the male patients. In addition, increased expression of lnc-C22orf32-1 and lnc-ZNF674-1 was associated with advanced tumor stages. Recurrent NPC displayed a distinctive lncRNA expression pattern. lnc-BCL2L11-3 was significantly increased in the recurrent NPC tissues. In addition, significant reduction of lnc-AL355149.1-1 and lnc-ZNF674-1 was observed in the recurrent NPC tissues. Conclusions. Our results demonstrated that it is feasible to identify the differentially expressed lncRNA in the microarray dataset by functional reannotation. The association of lncRNA with gender and tumor size implicated that lncRNA possibly plays a part in the pathogenesis of primary NPC. Further, the distinctive lncRNA identified in the recurrent NPC may reveal a distinctive development mechanism underlying tumor recurrence.