Integrative bioinformatics and molecular analysis revealed the roles of mTOR/S6K Axis, CASC15, and miR-30a-3p in laryngeal squamous cell carcinoma

Dysregulation of signaling pathways contributes substantially to the initiation and progression of laryngeal squamous cell carcinoma (LSCC). This study aimed to elucidate the mTOR and S6 kinase (S6K) gene expression levels, clinical significance, interplay of the mTOR/ S6K axis, miR-30a-3p, and the long non-coding RNA CASC15 in LSCC using bioinformatics tools. RNA-seq datasets (TCGA and GEO) were analyzed through bioinformatics and network-based tools to identify candidate pathways, miRNAs, and lncRNAs using R and Cytoscape. mTOR, S6K, miR-30a-3p, and CASC15 gene expression levels and mTOR and S6K protein values were measured in paired tumor (n = 54) and adjacent normal tissues (n = 54) using RT-qPCR and western blotting, respectively. Network analysis predicted that the mTOR/S6K regulatory axis is associated with miR-30a-3p and CASC15. The mTOR (p < 0.01), S6K (p < 0.0001), and CASC15 (p = 0.021) gene expression levels were significantly upregulated, whereas miR-30a-3p was markedly downregulated (p < 0.0001). miR-30a-3p expression levels showed inversely correlated to mTOR (p = 0.05) and S6K (p = 0.01), while CASC15 correlated positively to both mTOR (p = 0.00) and S6K (p = 0.00). The mTOR/S6K signaling axis is markedly activated in LSCC. CASC15 may act as an oncogenic lncRNA, whereas miR-30a-3p may function as a tumor-suppressive miRNA, suggesting their potential as molecular targets in LSCC.