Metformin Inhibits the Growth of Hypopharyngeal Squamous Cell Carcinoma of Fadu Cell and Down-Regulates LncAROD to Improve Prognosis

Background: Hypopharyngeal Squamous Cell Carcinoma(HSCC) is associated with a poor prognosis due to challenges in early detection, early metastasis, and limited treatment options. Objective: This study aims to investigate the effect of metformin on HSCC and identify potential prognostic factors associated with this carcinoma. Methods: The effects of metformin in HSCC cells were tested by functional assays in vitro. A xenograft tumor model was established, which was further examined by H&E staining, immunohistochemistry, and transmission electron microscopy (TEM). RNA sequencing analysis was employed to investigate the effects of metformin on gene expression and associated pathways. Bioinformatic analysis was further conducted to elucidate potential mechanisms and their correlation with gene expression, the tumor immune microenvironment, and survival prognosis. Finally, we further assessed the effect on FaDu cells by knocking down lncAROD using siRNAs. Results: The results demonstrated that metformin significantly reduced cell viability and migration, while promoting apoptosis and inducing cell cycle arrest in FaDu cells. WB analysis revealed that metformin inhibits the development of FaDu cells, possibly through the EMT pathway. In vivo studies indicate that metformin effectively inhibits tumor growth, promotes apoptosis, and autophagy. RNA-seq analysis revealed that metformin led to the upregulation of 1,697 genes and the downregulation of 858 genes, particularly highlighting a significant reduction in lncAROD, which were subsequently verified by qRT-PCR. Bioinformatic analysis demonstrated that lncAROD is highly expressed, with patients exhibiting higher levels of lncAROD showing poorer prognoses. Knockdown of lncAROD can reduce the proliferation, migration, and invasion of FaDu cells. Conclusion: This finding presents a novel approach to the clinical management of HSCC, indicating that metformin influences various processes related to the growth and progression of HSCC. Specifically, it reduces lncAROD expression and inhibits tumor progression, suggesting that lncAROD may serve as a valuable biomarker for evaluating the prognosis of HSCC.