Exosomal lncRNA LINC02191 Promotes Laryngeal Squamous cell Carcinoma Progression by Targeting miR-204-5p/RAB22A Axis and Regulating PI3K/Akt/mTOR Pathway.

Recent research has explored the potential use of serum-derived biomarkers in cancer screening, and mounting evidence has illustrated the pivotal roles of long noncoding RNAs (lncRNAs) in regulating laryngeal squamous cell carcinoma (LSCC) progression. LINC02191 is a newly identified lncRNA and no studies have investigated its role in malignant tumors. This study aims to explore the functions and mechanisms of lncRNA LINC02191 in LSCC. LINC02191 was knocked down in LSCC cells using shRNAs for loss-of-function experiments. RT-qPCR revealed that LINC02191 was upregulated in LSCC patients' serum exosomes, tissues and cells. Western blotting and RT-qPCR were implemented for detecting molecular protein and RNA levels. Colony formation, CCK-8, wound healing and Transwell assays were employed for examining LSCC cell malignant behaviors in vitro. A tumor-bearing mouse model (n = 4/group) was established for examining LINC02191 role in vivo. The results showed that LINC02191 silencing hindered LSCC cell proliferation, invasiveness, migration as well as EMT in vitro and impeded tumorigenesis in xenograft mouse model. Luciferase reporter assay was utilized for verifying the interaction between LINC02191, miR-204-5p and RAB22A. Pearson correlation analysis was employed to evaluate their expression correlation in LSCC tissue specimens (N = 30). Mechanistically, LINC02191 upregulated RAB22A by binding to miR-204-5p, and knocking down LINC02191 inhibited PI3K/Akt/mTOR signaling transduction in LSCC cells and tumor-bearing mice. Moreover, RAB22A overexpression reversed LINC02191 depletion-triggered suppression of LSCC cell aggressiveness and inactivation of PI3K/Akt/mTOR signaling. In conclusion, LINC02191 aggravates LSCC by targeting miR-204-5p/RAB22A/PI3K/Akt/mTOR signaling pathway, which indicates that LINC02191 may serve as a promising target for LSCC treatment.