Long intergenic non-protein coding RNA 02570 promotes nasopharyngeal carcinoma progression by adsorbing microRNA miR-4649-3p thereby upregulating both sterol regulatory element binding protein 1, and fatty acid synthase.

Our previous studies have elucidated a possible connection between long intergenic non-protein coding RNA 2570 (LINC02570) and nasopharyngeal carcinoma (NPC). However, the precise mechanism by which LINC02570 promotes NPC remains unknown. We used quantitative polymerase chain reaction (qPCR) to detect LINC02570 expression in nasopharyngeal cell lines, NPC tissues, and chronic rhinitis tissues. Subcellular LINC02570 localization was confirmed by fluorescence in situ hybridization (FISH). The effects of LINC02570 stable knockdown and overexpression on viabillity, proliferation, migration, and invasion were analyzed using 3-(4,5-Dimethyl-2-Thiazolyl)-2,5-Diphenyl-2-H-Tetrazolium bromide (MTT), a colorimetric focus-formation assay, a wound healing assay, and transwell assays. RNA crosstalk analysis in silico predicted microRNA-4649-3p (miR-4649-3p) binding to LINC02570 or sterol regulatory element binding transcription factor 1 (SREBF1). A dual luciferase reporter assay was used to confirm potential interactions. Sterol regulatory element binding protein 1 (SREBP1) and fatty acid synthase (FASN) expression were detected by western blotting. The results suggest that LINC02570 is upregulated in late clinical stage NPC patients, and promotes NPC progression by adsorbing miR-4649-3p to up-regulate SREBP1 and FASN. This study elucidates a potential chemotherapeutic target involved in lipid metabolism in NPC.

Stable knockdown of ZBTB7A promotes cell proliferation and progression in nasopharyngeal carcinoma.

AIMS: Although high expression of ZBTB7A is positively relative to metastasis in nasopharyngeal carcinoma (NPC) patients, the association between its low expression and metastasis of NPC remains unclear. The present study aimed to definitely identify the association. METHODS: The level of ZBTB7A was effectively knocked down by stable transfection of short hair RNA plasmid in NPC cell lines CNE2 and 5-8F (shRNA-CNE2 and shRNA-5-8F), compared with the cells that stably transfected empty plasmid (NC-CNE2 and NC-5-8F). The levels of ZBTB7A were assessed by real-time polymerase chain reaction and Western blot in the cell lines. MTT assay, colorimetric focus-formation assay, flow cytometry, wound healing assay, transwell assays, and xenograft model were performed to analyze cell vitality, proliferation, cell cycle, migration, invasion, and tumorigenicity. RESULTS: The levels of ZBTB7A were effectively reduced in shRNA-CNE2 and shRNA-5-8F. Their carcinogenicity was stronger separately than the abilities of NC-CNE2 and NC-5-8F. NC-CNE2 and shRNA-CNE2 were selected to establish the xenograft model because of their stronger tumorigenicity than NC-6-10B and shRNA-5-8F. The assay showed that shRNA-CNE2 had stronger tumorigenicity than NC-CNE2. CONCLUSIONS: The results demonstrated the reverse association between the expression of ZBTB7A and the tumorigenicity of NPC. We postulate that some oncogenic pathways, which are suppressed by ZBTB7A, will vicariously promote the proliferation and progression of NPC when ZBTB7A is decreased.

Differences in Zbtb7a expression cause heterogeneous changes in human nasopharyngeal carcinoma CNE3 sublines.

The present study aimed to determine the association between changes in Zbtb7a expression levels and heterogeneity of nasopharyngeal carcinoma (NPC) CNE3 sublines. CNE3 sublines were established by screening of serial dilution and continuous passage. Proliferative ability and tumorigenicity of the sublines were analyzed separately by soft-agar colony formation and mouse studies. The NPC tissues from mice were analyzed by histological evaluation and immunohistochemistry. The expression levels of Zbtb7a mRNA and protein were analyzed separately by quantitative reverse transcription polymerase chain reaction and western blotting. According to findings from the soft-agar colony formation and mouse studies, two sublines with increased tumorigenicity compared with other sublines were transfected transiently with Zbtb7a short hairpin RNA (shRNA) recombinant plasmid. The changes in viability, migration and invasion abilities were evaluated separately by MTT, colorimetric focus-formation, Transwell migration and invasion assays. The sublines CNE3-GX6 and CNE3-GX11 were selected for subsequent study due to increased tumorigenicity and increased Zbtb7a expression levels compared with the other sublines. High metastatic potency was not observed in all of the sublines. Zbtb7a expression levels were positively associated with tumorigenic degree of the sublines. The growth, migration and invasion abilities of the sublines transfected with Zbtb7a shRNA plasmid were decreased compared with the cells transfected with empty vector in the negative control group. The findings suggest Zbtb7a expression levels may be associated with heterogeneity of CNE3 sublines. Therefore, Zbtb7a may have an important role in the regulatory mechanism of NPC heterogeneity.