Long non-coding RNA SPRY4-IT1 promotes proliferation and metastasis in nasopharyngeal carcinoma cell.

Background: Long non-coding RNA SPRY4 intronic transcript 1 (Lnc RNA SPRY4-IT1) was aberrant-expressed in various kinds of cancer. Increasing evidence demonstrated that lnc RNAs involved in tumorigenesis and metastasis. In this study, we aimed to explore the biological role of SPRY4-IT1 on the phenotype of nasopharyngeal carcinoma (NPC) in vitro and in vivo.

Methods: The expression level of SPRY4-IT1 in NPC cell lines were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell Counting Kit-8 (CCK-8) and colony formation assay were used to detect cell proliferation. Wound-healing assay, transwell assay and animal experiment were performed to evaluate the ability of cell migration and metastasis. Cell cycle distribution and apoptosis were determined by flow cytometry. Western blotting and immunofluorescence were employed to identify protein expression.

Results: SPRY4-IT1 was significantly up-regulated in several NPC cell lines (6-10B, CNE-2, and HONE-1) compared with human immortalized nasopharyngeal epithelial cell (NP69). Silencing of SPRY4-IT1 inhibited proliferation, migration, and metastasis, and induced significant G2/M phase arrest and apoptosis. Western blotting showed that the expression levels of cell cycle-related proteins (cyclin B1, cdc2 and p-cdc2) were down-regulated and apoptosis-associated proteins (PARP, cleaved PARP and cleaved caspase-3) were up-regulated after knockdown of SPRY4-IT1. The expression level of E-cadherin was increased and the expression of Vimentin, Snail and Twist1 were decreased after the SPRY4-IT1 knockdown.

Conclusion: lncRNA SPRY4-IT1 played a significant role in NPC proliferation, migration and metastasis, suggesting that SPRY4-IT1 might be a potential therapeutic target for the treatment of NPC.