HIF-1α induced NID1 expression promotes pulmonary metastases via the PI3K-AKT pathway in salivary gland adenoid cystic carcinoma.

BACKGROUND: This study aimed to investigate the potential role of nidogen 1 (NID1), a basement membrane component, in the growth and metastasis of salivary gland adenoid cystic carcinoma (SACC) and the underlying molecular mechanism.

METHODS: High-throughput next-generation sequencing was used to compare the gene expression profiles of SACC with and without lung metastasis. Luciferase gene reporter assays were used to measure the NID1 promoter activity. BALB/c nude mice were used to establish a lung metastasis model of SACC to evaluate the prometastatic activity of NID1. ChIP and dual-luciferase reporter assays were performed to confirm the HIF-1α-binding site in the NID1 promoter.

RESULTS: NID1 expression in SACC was significantly increased and associated with lung metastasis (P = 0.011). The elevated NID1 expression was a predictor of poor outcomes in patients with SACC (P < 0.05). Overexpression of NID1 promoted cancer cell migration and invasion through PI3K/AKT pathway activation and subsequent epithelial-mesenchymal transition (EMT), as indicated by the upregulation of N-cadherin and vimentin. Furthermore, in vivo live monitoring of a mouse model of lung cancer demonstrated the pro-metastatic role of NID1 in SACC cell lung metastasis. Hypoxia-inducible factor 1α (HIF-1α) upregulation via transfection of an HIF-1α-overexpressing plasmid enhanced HIF-1α binding to the NID1 promoter and the subsequent transcriptional activity and expression of NID1.

CONCLUSION: HIF-1α-activated NID1 overexpression promotes SACC cell metastasis via PI3K/AKT pathway activation and EMT. Thus, NID1 could be a novel biomarker and therapeutic target for preventing metastasis and treating patients with SACC in future.