ABSTRACT
BACKGROUND: Extracellular vesicles (EVs) have been revealed to facilitate the development of oral squamous cavity cell carcinoma (OCSCC), while its supporting role in lymph node metastases is under continuous investigation. This study aimed to examine the function of cancer-associated fibroblasts (CAF)-derived EVs (CAF-EVs) during lymph node metastasis in OCSCC and the mechanisms. METHODS: CAF were isolated from OCSCC tissues of patients, and CAF-EVs were extracted and identified. EdU, colony formation, wound healing, and Transwell assays were performed. The OCSCC cells before and after CAF-EVs treatment were injected into mice to probe the effects of CAF-EVs on tumor growth and lymph node metastasis, respectively. The effect of CAF-EVs treatment on transcriptome changes in OCSCC cells was analyzed. Clinical data of patients with OCSCC were analyzed to determine the prognostic significance of the selected genes. Finally, loss-of-function assays were conducted to corroborate the involvement of polycomb complex protein BMI-1 (BMI1) and integrin beta1 (ITGB1). RESULTS: CAF-EVs promoted the malignant behavior of OCSCC cells and accelerated tumor growth and lymph node metastasis in mice. CAF-EVs significantly increased the expression of BMI1 and ITGB1, and the expression of BMI1 and ITGB1 was negatively correlated with the overall survival and relapse-free survival of OCSCC patients. Knockdown of BMI1 or ITGB1 in OCSCC cells abated the promoting effects of CAF-EVs in vitro and in vivo. CONCLUSION: CAF-EVs elicited the metastasis-promoting properties in OCSCC by elevating BMI1 and ITGB1, suggesting that BMI1 and ITGB1 could be potential biomarkers and therapeutic targets for OCSCC.
Subject(s)
Cancer-Associated Fibroblasts , Carcinoma, Squamous Cell , Extracellular Vesicles , Head and Neck Neoplasms , Mouth Neoplasms , Animals , Humans , Mice , Head and Neck Neoplasms/metabolism , Integrin beta1/genetics , Lymphatic Metastasis/genetics , Mouth Neoplasms/metabolism , Neoplasm Recurrence, Local , Polycomb Repressive Complex 1/genetics , Squamous Cell Carcinoma of Head and Neck/metabolismABSTRACT
Oral squamous cell carcinoma (OSCC) is a frequent malignant tumor worldwide. Long noncoding RNAs (lncRNAs) are known to play key roles in different types of cancer, including OSCC. It was previously reported that lncRNA deleted in lymphocytic leukemia 1 (DLEU1) is notably upregulated in OSCC; however, the role of DLEU1 in OSCC remains unclear. Gene and protein expression levels in OSCC cells were detected by reverse transcriptionquantitative PCR and western blotting, respectively, in the present study. A Transwell assay was performed to measure cell migration and invasion. Flow cytometry was used to detect cell apoptosis, and the dualluciferase reporter assay was applied to confirm the interaction between DLEU1, microRNA (miR)1495p and CDK6 in OSCC cells. DLEU1 expression was negatively associated with the survival rate of patients with OSCC. In addition, silencing of DLEU1 notably inhibited the proliferation of OSCC cells by inducing apoptosis. Meanwhile, DLEU1 directly bound to miR1495p, and CDK6 was found to be the direct target of miR1495p. Furthermore, DLEU1 knockdowninduced inhibition of OSCC cell proliferation was significantly reversed by the miR1495p antagomir. Knockdown of lncRNA DLEU1 reversed the proliferation of OSCC cells via regulation of the miR1495p/CDK6 axis. Thus, DLEU1 may serve as a novel target for treating OSCC.
Subject(s)
Carcinogenesis/drug effects , Carcinogenesis/genetics , Carcinoma, Squamous Cell/drug therapy , Cyclin-Dependent Kinase 6/metabolism , MicroRNAs/metabolism , Mouth Neoplasms/drug therapy , RNA, Long Noncoding/genetics , RNA, Long Noncoding/pharmacology , Apoptosis , Carcinoma, Squamous Cell/pathology , Cell Line, Tumor , Cell Movement , Cell Transformation, Neoplastic/genetics , China , Cyclin-Dependent Kinase 6/genetics , Female , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Humans , Male , MicroRNAs/genetics , Middle Aged , Mouth Neoplasms/pathologyABSTRACT
BACKGROUND: Oral squamous cell carcinoma (OSCC) is one of the most comment types of oral malignancies. SET-domain-containing protein 6 (SETD6) was recently identified as an important regulator of multiple signaling pathways through methylating protein substrates. Meanwhile, SETD6 is known to participate in multiple cancers. However, the role of SETD6 in OSCC remains unclear. METHODS: Gene and protein expressions in OSCC cells or tissues were detected by RT-qPCR and western blot, respectively. In addition, CCK-8 assay was used to test the cell viability. A transwell assay was performed to measure cell migration and invasion. Flow cytometry was used to test cell apoptosis and cycle. Meanwhile, methylation-specific PCR (MSP) was used to detect the status of promoter methylation. RESULTS: SETD6 was significantly upregulated in OSCC tissues. In addition, knockdown of SETD6 notably inhibited the proliferation and induced the apoptosis of OSCC cells. Furthermore, silencing of SETD6 notably suppressed the migration and invasion of OSCC cells. Meanwhile, SETD6 siRNA significantly inhibited the promoter methylation of RelA (NF-κB p65) and PAK4. Furthermore, SETD6 siRNA induced G1 arrest in OSCC cells. CONCLUSION: Knockdown of SETD6 inhibits the tumorigenesis of OSCC by suppressing promoter methylation of PAK4 and RelA. Therefore, our study might shed new light on exploring strategies for the treatment of OSCC.
