Oral squamous cell carcinoma (OSCC), with high potential for metastasis, is the most common malignant tumor of the head and neck. Cancer-associated fibroblasts (CAFs) are the main stromal cells in the microenvironment and aggravate tumor progression. However, whether CAFs are associated with the progression of OSCC remains unknown and the underlying mechanism remains unclear. In the present study, the role of CAFs in mediating OSCC cell migration and invasion was investigated, and the participation of exosomal miR-382-5p in this process was elucidated. In this study, according to the α-SMA staining with immunohistochemistry, 47 OSCC patients were divided into CAFs-rich and CAFs poor groups, and association of CAF density and clinicopathologic features of the OSCC patients were analyzed with Pearson χ 2 test. Transwell assay was used for evaluating cell migration and invasion ability of OSCC cells after being co-cultured with NFs or CAFs, or after added exosomes. qPCR was used to detect the expression of miR-382-5p. Western blot analysis was used to measure the expression of migration and invasion-associated proteins. In the present study, the CAF density in tumor tissues was found to be relevant to OSCC lymph node metastasis and TNM stage. Furthermore, we revealed that miR-382-5p was overexpressed in CAFs compared with that in fibroblasts of adjacent normal tissue and miR-382-5p overexpression was responsible for OSCC cell migration and invasion. Finally, we demonstrated that CAF-derived exosomes transported miR-382-5p to OSCC cells. The present study confirmed a new mechanism of CAF-facilitated OSCC progression and may be beneficial for identifying new cancer therapeutic targets.

In tumor microenvironment, macrophages as a polarized M2 population promote tumor progression via releasing multiple cytokines and chemokines. A brown seaweed fucose-rich polysaccharide, fucoidan has antitumor activity and immune modulation through affecting tumor cells and lymphocytes. Here, we focused on the effect of fucoidan on macrophages especially M2 subtype. Our results demonstrated that fucoidan down-regulated partial cytokines and chemokines, especially a M2-type chemokine CCL22. Furthermore, fucoidan inhibited tumor cells migration and CD4+ T lymphocytes, especially Treg cells, recruitment induced by M2 macrophages conditioned medium through suppression of CCL22. Mechanismly, fucoidan inhibited CCL22 via suppressing p65-NF-κB phosphorylation and nuclear translocation. In addition, p38-MAPK and PI3K-AKT also affected the expression of CCL22 through differential modulation of NF-κB transcriptional activity. Taken together, we reveal an interesting result that fucoidan can inhibit tumor cell migration and lymphocytes recruitment by suppressing CCL22 in M2 macrophages via NF-κB-dependent transcription, which may be a novel and promising mechanism for tumor immunotherapy.

Oral squamous cell carcinoma (OSCC) is one of the most common types of malignant head and neck tumor, which poses a serious threat to human health. In recent years, the incidence of OSCC has been increasing, while the prognosis has not significantly improved. Elucidation of the molecular mechanisms underlying the development of OSCC may provide novel therapeutic strategies. In the present study, the gene expression profiles from 4 datasets, including 244 OSCC and 95 normal oral mucosa samples, were subjected to statistical and Bioinformatics analysis. A total of 34 differentially expressed genes (DEGs) were identified, among which 14 were upregulated and 20 were downregulated in OSCC compared with normal oral mucosa tissues. Gene Ontology enrichment analysis indicated that the DEGs were mainly involved in regulation of the immune response, cell adhesion and cell proliferative processes. The Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the DEGs were mainly associated with the phosphoinositide-3 kinase Akt and Toll-like receptor signaling pathway. The key candidate DEGs were identified from the complex protein-protein interaction network, and secreted phosphoprotein 1 (SPP1), integrin subunit α 3 and plasminogen activator, urokinase (PLAU) were confirmed to be significantly associated with the survival rate. Cell Counting Kit-8 and Transwell assays demonstrated that SPP1 and PLAU regulate cell proliferation, migration and invasion. The candidate genes/pathways identified in the present study may include promising diagnostic biomarkers or therapeutic targets for OSCC.