CH25H Promotes Autophagy and Regulates the Malignant Progression of Laryngeal Squamous Cell Carcinoma Through the PI3K-AKT Pathway

Background: Laryngeal squamous cell carcinoma (LSCC) is a type of cancer of the respiratory tract that often presents with subtle symptoms at the early stage and is susceptible to recurrence and metastasis.

Materials and methods: To find out key regulatory genes involved in LSCC development, we downloaded LSCC-related sequencing datasets for bioinformatics analysis. WGCNA was performed on GSE142083 and differential analysis was conducted on GSE51985 and TCGA-HNSC. Intersection genes were taken from the above three datasets. To confirm the function of genes, we overexpressed and knocked down genes in cells and treated them with autophagy agonist Rapamycin and PI3K-AKT pathway inhibitor. At the cellular level, the expression of CH25H, autophagy-related proteins (LC3 I, LC3 II, p62, and Beclin 1), and PI3K-AKT pathway-related proteins (PI3K, AKT, and p-AKT) were assessed via Western blot; the mRNA level of CH25H was evaluated through qRT-PCR; the cell activity was examined by CCK8; the apoptosis was assessed through flow cytometry; and the cell migration and invasion were assessed through wound healing and Transwell assays.

Results: Through bioinformatics analysis, we screened 7 genes (CH25H, NELL2, STC2, TMEM158, ZIC2, HOXD11, and HOXD10). Ultimately, CH25H was selected for follow-up experiments. By detecting CH25H expression in human immortalized keratinocytes (HaCaT) and LSCC cells (Tu-686, SNU899, and AMC-HN-8), it was found out that CH25H expression was higher in HaCaT cells than in LSCC cells. To elucidate the role of CH25H in LSCC development, we overexpressed CH25H in Tu-686 cells and downregulated its expression in AMC-HN-8 cells. CH25H was revealed to reduce the proliferation, activity, invasion, and migration of LSCC cells while increasing their apoptosis levels. Significant changes were also observed in the expressions of autophagy- and PI3K-AKT pathway-related proteins. To further investigate the roles of autophagy and the PI3K-AKT pathway in LSCC development, we respectively employed autophagy agonists and inhibitors targeting the PI3K-AKT pathway to intervene the cells, and found that CH25H regulated the PI3K-AKT pathway to promote autophagy, thus enhancing the apoptosis of LSCC cells. We further investigated CH25H's impact on tumor growth, autophagy, and the PI3K-AKT pathway at the animal level and found that CH25H promoted autophagy of LSCC cells and inhibited the PI3K-AKT pathway, and ultimately inhibiting the progression of LSCC.

Conclusions: In summary, CH25H promotes autophagy and affects the malignant progression of LSCC through the PI3K-AKT pathway.