The Expression And Mechanism Study Of Long Non-Coding RNA LINC01133 In Nasopharyngeal Carcinoma

Background & Aims: Long non-coding RNAs(lncRNAs)have been reported as the vital regulators of various cancers including nasopharyngeal carcinoma(NPC).An increasing number of studies have suggested that lncRNA LINC01133 is dysregulated and involved in human carcinogenesis.Our study aimed to explore the role of LINC01133 in NPC progression.Methods: The expression level of LINC01133 was analyzed via quantitative RT-PCR(qRT-PCR)arrays in human NPC tissues and cell lines.The loss and gain of function experiments were carried out to explore the biological effects of LINC01133 in vitro.The function of LINC01133 in vivo was detected through NPC xenograft tumor growth and spontaneous lymph node metastatic mice model.Expressions of relevant proteins were assessed by Western blot analysis.Subcellular fractionation location and fluorescence in situ hybridization(FISH)assay were carried out to determine the localization of LINC01133.Besides,the insights into the potential mechanisms of LINC01133 interacting with Y-box binding protein 1(YBX1)were validated by RNA pull-down assay,RNA immunoprecipitation(RIP)assays,qRT-PCR arrays,Western blot analysis and rescue experiments.Results: LINC01133 was downregulated in NPC tissues and cell lines.Exotic expression of LINC01133 inhibited NPC cell proliferation,invasion and migration both in vitro and in vivo.Importantly,LINC01133 was observed mainly distributed in the nucleus.RNA pull-down and RIP assays showed that LINC01133 directly combined with YBX1,and YBX1 can partly reverse the repression of NPC cell proliferation,migration,and invasion due to LINC01133 overexpression.The interaction between LINC01133 and YBX1 did not alter the protein levels of YBX1,but relatively changed its structure and functions.Our data also demonstrated that LINC01133 can suppress epithelial–mesenchymal transition(EMT)via YBX1.Conclusions: Collectively,LINC01133 inhibits the malignant-biological behavior of NPC cells and the process of EMT by interacting with YBX1,thereby suggesting a novel biomarker for the prognosis and treatment of NPC.