# Decreased BIRC5-206 promotes epithelial–mesenchymal transition in nasopharyngeal carcinoma through sponging miR-145-5p

## TL;DR

Low levels of BIRC5-206 in nasopharyngeal carcinoma cells increase cancer spread by affecting cell behavior and a specific signaling pathway.

## Contribution

This study reveals that BIRC5-206 suppresses cancer metastasis by regulating miR-145-5p/CD40 signaling in nasopharyngeal carcinoma.

## Key findings

- Silencing BIRC5-206 reduces apoptosis and increases invasion of nasopharyngeal carcinoma cells.
- Low BIRC5-206 expression promotes epithelial-mesenchymal transition by altering cadherin and vimentin levels.
- BIRC5-206 facilitates metastasis suppression via the miR-145-5p/CD40 signaling pathway.

## Abstract

Metastasis significantly contributes to the poor prognosis of advanced nasopharyngeal carcinoma (NPC). Our prior studies have demonstrated a decrease in BIRC5-206 expression in NPC, which promotes disease progression. However, the role of BIRC5-206 in the invasion and metastasis of NPC has not been fully elucidated. In this study, our objective was to explore the biological function and underlying mechanisms of BIRC5-206 in NPC. Additionally, we established an NPC mouse model of lung invasiveness using C666 cells to assess the impact of BIRC5-206 on NPC metastasis. Our results revealed that silencing BIRC5-206 inhibited apoptosis and enhanced the invasion of NPC cells, whereas its overexpression reversed these effects. Moreover, decreased BIRC5-206 expression significantly increased N-cadherin and Vimentin expression while reducing E-cadherin and occludin levels, both in vivo and in vitro. Additionally, silencing BIRC5-206 markedly augmented the formation of invasive foci in lung tissues. Rescue experiments further confirmed that decreased BIRC5-206 expression facilitates NPC metastasis via modulation of the miR-145-5p/CD40 signaling pathway. In summary, our study suggests that BIRC5-206 may serve as a potential prognostic biomarker and therapeutic target in the diagnosis and treatment of NPC.