Identifying KRT20 as a Potential Key Gene in Lymphatic Metastasis of Head and Neck Squamous Cell Carcinoma

Non-canonical RNA-binding protein ANXA11 regulates microRNA resorting into small extracellular vesicles to mediate cisplatin resistance

The sensitivity of laryngeal squamous cell carcinoma (LSCC) to chemotherapy shows large heterogeneity. The role of miRNA in small extracellular vesicles (sEV) in chemotherapy resistance is under investigation. However, the regulation and sorting mechanism of sEV miRNAs remains unclear. In this study, small RNA sequencing was used to explore miRNA expression profiles in sEV of LSCC after cisplatin stimulation; RNA pull-down, mass spectrometry, and EMSA were used to clarify the binding of candidate RNA-binding protein (RBP) and candidate miRNA. Immunostaining and microRNA fluorescence in situ hybridization were performed to identify how candidate RBP affects miRNA stability and nuclear/cytoplasmic distribution. In vivo experiments were performed to verify the biological functions and response to cisplatin of candidate RBP. We found that cisplatin stimulation induced increased expression of miR-148a-3p and sEV sorting. ANXA11 binds to miR-148a-3p in a sequence-specific manner. ANXA11 inhibits tumor cell proliferation and drug resistance by binding to and retaining miR-148a-3p. Cisplatin stimulation reduced ANXA11 expression and promoted miR-148a-3p efflux through sEV pathways. ANXA11 overexpression reduced in vivo tumor proliferation and cisplatin-resistance. Taken together, ANXA11 mediates cisplatin resistance through sEV miRNA resorting. Mechanically, ANXA11 binds to miR-148a-3p in a sequence-specific manner to regulate its resorting and thus influences tumor proliferation and chemoresistance.

Nicotine downregulates miR-375-3p via neurotrophic tyrosine receptor kinase 2 to enhance the malignant behaviors of laryngopharyngeal squamous epithelial cells

Nicotine exposure from smoking constitutes a significant global public health concern. Furthermore, smoking represents a pivotal risk factor for head and neck squamous cell carcinoma (HNSCC). However, the influence of nicotine on HNSCC remains relatively underexplored. Our aim was to unravel the molecular mechanisms that underlie the effect of nicotine on the metastatic cascade of HNSCC. In this study, we discovered a significant association between smoking and HNSCC metastasis and prognosis. Nicotine significantly enhanced HNSCC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro. Analysis of TCGA-HNSCC and FDEENT-HNSCC cohorts revealed reduced miR-375-3p levels in HNSCC tumor tissues, particularly among current smokers. Additionally, miR-375-3p level was strongly correlated with both lymph node metastasis and tumor stage. By downregulating miR-375-3p, nicotine promotes HNSCC cell metastasis in vitro and hematogenous metastatic capacity in vivo. Utilizing transcriptomic sequencing, molecular docking, dual-luciferase reporter assay, and fluorescence in situ hybridization (FISH), we demonstrated that miR-375-3p specifically binds to 3' untranslated region (3'UTR) of NTRK2 mRNA. Thus, this study uncovers a novel nicotine-induced mechanism involving miR-375-3p-mediated NTRK2 targeting, which promotes HNSCC metastasis. These findings have implications for improving the prognosis of patients with HNSCC, especially in smokers.