ABSTRACT
Background: The purpose of this study was to determine the association between m6A-modified lncRNAs, immune infiltration, and PD-L1 expression in patients with primary head and neck squamous cell carcinoma (HNSCC) and the prognostic value of m6A RNA methylation-related lncRNAs in HNSCC. Methods: We downloaded the RNA-seq transcriptome data and the clinical information for HNSCC from the TCGA databases and used consensus clustering analysis to divide the samples into two groups. To identify a risk signature, least absolute shrinkage and selection operator (LASSO) analyses were conducted. the association between m6A-modified lncRNAs, immune infiltration, and PD-L1 expression were detected by using the R packages. What is more, we used cBioPortal tools to identify genomic alterations and PD-L1 mutations and Gene set enrichment analysis (GSEA) was utilized to predict downstream access of two clusters. Results: Notably, lncRNAs play significant roles in tumorigenesis and development. In total, we identified two subtypes of HNSCC according to consensus clustering of the m6A RNA methylation-related lncRNAs, and the T, grade and age were proven to be related to the subtypes. The Cox regression and LASSO analyses identified a risk signature including GRHL3-AS1, AL121845.4, AC116914.2, AL513190.1. The prognostic value of the risk signature was then proven. The selected gene PD-L1 mutations and the immune infiltration in both groups were further explored. Conclusion: Collectively, our study elucidated the important role of m6A RNA methylation- related lncRNAs in tumor microenvironment of HNSCC. The proposed m6A RNA methylation- related lncRNAs might serve as crucial mediators of tumor microenvironment of HNSCC, representing promising therapeutic targets in improving immunotherapeutic efficacy.
ABSTRACT
CRM197 is a naturally nontoxic diphtheria toxin mutant that binds and inhibits heparin-binding epidermal growth factor-like growth factor. CRM197 serves as carrier protein for vaccine and other therapeutic agents. CRM197 also inhibits the growth, migration, invasion, and induces apoptosis in various tumors. Vascular cell adhesion molecule-1 (VCAM-1) is an important cell surface adhesion molecule associated with malignancy of gliomas. In this work, we aimed to investigate the role and mechanism of CRM197 combined with shRNA interference of VCAM-1 (shRNA-VCAM-1) on the migration, invasion, and apoptosis of glioblastoma cells. U87 and U251 human glioblastoma cells were treated with CRM197 (10 µg/ml) and shRNA interfering technology was employed to silence VCAM-1 expression. Cell viability, migration, invasiveness, and apoptosis were assessed with CCK8, Transwell and Annexin V-PE/7-AAD staining. Activation of cleaved caspase-3, 8, and 9, activity of matrix metalloproteinase-2/9 (MMP-2/9), and expression of phosphorylated Akt (p-Akt) were also checked. Results showed that CRM197 and shRNA-VCAM-1 not only significantly inhibited the cell proliferation, migration, invasion, but also promoted the apoptosis of U87 and U251 cells. Combined treatment of both displayed enhanced inhibitory effects on the malignant biological behavior of glioma cells. The activation of cleaved caspase-3, 8, 9 was promoted, activity of MMP-2 and MMP-9 and expression of p-Akt were inhibited significantly by the treatment of CRM197 and shRNA-VCAM-1 alone or in combination, indicating that the combination of CRM197 with shRNA-VCAM-1 additively inhibited the malignant behavior of human glioblastoma cells via activating caspase-3, 8, 9 as well as inhibiting MMP-2, MMP-9, and Akt pathway.
Subject(s)
Antineoplastic Agents/pharmacology , Bacterial Proteins/pharmacology , Combined Modality Therapy/methods , Genetic Therapy/methods , Glioblastoma/pathology , Vascular Cell Adhesion Molecule-1/metabolism , Apoptosis/drug effects , Blotting, Western , Cell Line, Tumor , Cell Movement/drug effects , Humans , RNA Interference , RNA, Small Interfering , Reverse Transcriptase Polymerase Chain Reaction , TransfectionABSTRACT
BACKGROUND AND AIMS: Great interest persists in useful therapeutic targets in glioblastoma (GBM). Deregulation of microRNAs (miRNAs) expression has been associated with cancer formation through alterations in gene targets. In this study, we reported the role of miR-101 in human glioblastoma stem cells (GSCs) and the potential mechanisms. METHODS AND RESULTS: Quantitative real-time PCR showed that miR-101 expression was decreased in GSCs. Overexpression of miR-101 reduced the proliferation, migration, invasion, and promoted apoptosis of GSCs. One direct target of miR-101, the transcription factor Kruppel-like factor 6 (KLF6), was identified using the Dual-Luciferase Reporter Assay System, which mediated the tumor suppressor activity of miR-101. This process was coincided with the reduced expression of Chitinase-3-like protein 1 (CHI3L1) whose promoter could be bound with and be promoted by KLF6 demonstrated by luciferase assays and chromatin immunoprecipitation assays. The downregulation of CHI3L1 led to the inactivation of MEK1/2 and PI3K signal pathways. Furthermore, nude mice carrying the tumors of overexpressed miR-101 combined with knockdown of KLF6 produced the smallest tumors and showed the highest survival rate. CONCLUSIONS: Our findings provided a comprehensive analysis of miR-101 and further defining it as a potential therapeutic candidate for GBM.
