Abstract
OBJECTIVE: To investigate the influence of lactoferrin (LTF) on the anoikis-resistance of nasopharyngeal carcinoma (NPC) cells and explore its relationship with the protein kinase B (AKT) signaling pathway. METHODS: Anoikis-resistant HNE-1 and HONE-1 NPC cell lines were established. The proliferation and survival of cells were detected by Cell Counting Kit-8 (CCK8), while cell cycle and apoptosis were measured by flow cytometry. The transwell assay was used to evaluate invasion and metastasis abilities. The expression of matrix metallopeptidase-9 (MMP-9), vascular endothelial growth factor-A (VEGF-A), E-cadherin and Vimentin were assessed by Western blot. LTF plasmids and LTF shRNA plasmids were transfected into HNE-1 and HONE-1 cells, respectively, and the expression of E-cadherin, Vimentin, AKT and tropomyosin receptor kinase B (TrkB) proteins was detected by Western blot to clarify the role of LTF in anoikis-resistant NPC cells. RESULTS: Anoikis-resistant HNE-1 and HONE-1 NPC cell lines were successfully established. Compared to parental cells, these anoikis-resistant cells exhibited enhanced survival, reduced apoptosis, and significantly increased invasive ability. They also demonstrated elevated expression of VEGF-A, MMP-9, and Vimentin, alongside decreased E-cadherin, indicating epithelial-mesenchymal transition (EMT). Furthermore, the expression of AKT and TrkB was significantly upregulated in anoikis-resistant cells. Critically, LTF overexpression reversed this aggressive phenotype: it suppressed cell survival and invasion, induced G0/G1 cell cycle arrest, promoted apoptosis, and downregulated the expression of AKT and TrkB. Conversely, LTF knockdown produced opposing effects. CONCLUSION: Our study revealed that LTF inhibits anoikis-resistance and metastasis of NPC cells via the AKT signaling pathway.