ABSTRACT
Immune escape is an important mechanism in tumorigenesis. The aim of this study was to investigate roles of SKIL in tumorigenesis and immune escape of non-small-cell lung cancer (NSCLC). SKIL expression levels in NSCLC cell line, clinical sample, and adjacent normal tissue were measured by quantitative PCR, western blot, or immunohistochemistry. Lentivirus was used to overexpress/silence SKIL or TAZ expression. Malignant phenotypes of NSCLC cells were evaluated by colony formation, transwell, and MTT assays, and in xenograft mice model. Syngeneic mice model and flow cytometry were used to evaluate T cell infiltration. Quantitative PCR and western blot were applied to evaluate relevant mRNA and protein levels, respectively. Co-immunoprecipitation was applied to unveil the interaction between SKIL and TAZ. SKIL expression was higher in NSCLC tissue compared to adjacent normal tissue. Silencing of SKIL inhibited malignant phenotypes of NSCLC cells and promoted T cell infiltration. SKIL-knockdown inhibited autophagy and activated the STING pathway in NSCLC cells through down-regulation of TAZ. Silencing of TAZ cancelled the effects of SKIL overexpression on malignant phenotypes and autophagy of NSCLC cells. Inhibition of autophagy reversed the effects of SKIL/TAZ overexpression on the STING pathway. In conclusion, SKIL promoted tumorigenesis and immune escape of NSCLC cells through upregulation of TAZ/autophagy axis and inhibition on downstream STING pathway.
Subject(s)
Autophagy , Carcinogenesis/pathology , Carcinoma, Non-Small-Cell Lung/immunology , Immune Evasion , Intracellular Signaling Peptides and Proteins/metabolism , Lung Neoplasms/immunology , Proto-Oncogene Proteins/metabolism , Trans-Activators/metabolism , Up-Regulation , Animals , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Chemokines/metabolism , Gene Expression Regulation, Neoplastic , Gene Silencing , Humans , Intracellular Signaling Peptides and Proteins/genetics , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Membrane Proteins/metabolism , Mice, Inbred BALB C , Mice, Nude , Phenotype , Phosphorylation , Proto-Oncogene Proteins/genetics , Signal Transduction , T-Lymphocytes/immunology , Transcriptional Coactivator with PDZ-Binding Motif ProteinsABSTRACT
AIMS: Non-small cell lung cancer (NSCLC), characterized by extensive metastasis and poor prognosis, is the most common type of lung cancer. Dysregulation of certain lncRNAs is known to be linked to the tumorigenesis of NSCLC. However, the specific roles in NSCLC for many other lncRNAs, such as linc01088, remain largely unknown. MATERIALS AND METHODS: The expression patterns of linc01088, p21 and EZH2 were examined both in NSCLC tissues and cell lines using RT-qPCR assay. CCK-8, colony formation, immunofluorescence staining, and flow cytometry assays were employed to evaluate the effects of linc01088 on NSCLC cell proliferation properties. RNA immunoprecipitation (RIP) assay was performed to determine the direct binding relationship between linc01088 and zeste homolog 2 (EZH2). Western blot and RT-qPCR analysis were performed to assess p21 level within knockdown of either linc01088 or EZH2. Nude mouse subcutaneous NSCLC models were constructed for further validating the effects and mechanisms of linc01088 in vivo. KEY FINDINGS: linc01088 and EZH2 were highly expressed both in NSCLC tissues and cell lines. Knockdown of linc01088 suppressed the proliferation of NSCLC cells, and prolonged the G1 phase while shortened S and G2-M phases. RIP assay revealed the direct binding relationship between linc01088 and EZH2. Knockdown of either linc01088 or EZH2 induced up-regulation of p21 expression, which subsequently inhibited the tumor growth. SIGNIFICANCE: We demonstrated that linc01088 could promote cell proliferation via binding with EZH2 to repress p21, which aggravates the tumorigenesis of NSCLC. Therefore, linc01088 might be a potential oncogene and target for novel anti-tumor therapies.
Subject(s)
Biomarkers, Tumor/metabolism , Carcinoma, Non-Small-Cell Lung/secondary , Cyclin-Dependent Kinase Inhibitor p21/antagonists & inhibitors , Enhancer of Zeste Homolog 2 Protein/metabolism , Gene Expression Regulation, Neoplastic , Lung Neoplasms/pathology , RNA, Long Noncoding/genetics , Animals , Apoptosis , Biomarkers, Tumor/genetics , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Proliferation , Cyclin-Dependent Kinase Inhibitor p21/genetics , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Enhancer of Zeste Homolog 2 Protein/genetics , Female , Follow-Up Studies , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Middle Aged , Neoplasm Invasiveness , Neoplasm Metastasis , Prognosis , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
OBJECTIVE: 7 variable but nonculturable-state strains of Enterotoxigenic Escherichia coli (ETEC) during the routine bacterial subculture were found in our lab and their morphology and antigen studied. Biological features, antigens and pathogenicity of the revertants were also tested and compared to that of the initial strains in order to detect their variations. METHODS: Biological variations between the variable but nonculturable-state and the revertant of every strain were detected, using the routine gram-staining, reverting the isolates in animal intestinal, reverting their pathogenicity, serological agglutination, biochemical identifications and antibiotic resistance tests. RESULTS: For the 7 variable but nonculturable-state strains of ETEC,other than the trains that had changed into sphero vegetale cells, there were no other obvious variations found. However, high pathogenicity of these strains still remained. CONCLUSION: The presence of variable but nonculturable-state strains suggested that the routine method of bacteria storage should be changed and more attention should be paid to realize the existence of this kind of bacteria during the routine surveillance of the communicable diseases.
