SKIL facilitates tumorigenesis and immune escape of NSCLC via upregulating TAZ/autophagy axis.

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.

LncRNA NEAT1 Interacted With DNMT1 to Regulate Malignant Phenotype of Cancer Cell and Cytotoxic T Cell Infiltration via Epigenetic Inhibition of p53, cGAS, and STING in Lung Cancer.

PURPOSE: Lung cancer is the main cause of cancer-related mortality worldwide. We report here the biological role of nuclear paraspeckle assembly transcript 1 (NEAT1) in the pathogenesis of lung cancer and the underlying mechanisms. METHODS: Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blotting analysis were used to evaluate expression of mRNA and protein. RNA immunoprecipitation (RIP) assay, chromatin immunoprecipitation followed by qPCR analysis, and reporter assay were used to detect DNA/RNA and protein binding. Tumor-infiltrating lymphocytes were assessed with hematoxylin-eosin staining. Cytotoxic T cell infiltration was evaluated with flow cytometric analysis and immunohistochemistry (IHC) staining. The changes of cell viability and cell invasive and migratory ability were analyzed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), colony formation, and Transwell assays, respectively. Syngeneic tumor model was set up to evaluate antitumor effect. RESULTS: The results showed that NEAT1 was overexpressed in lung cancer tissues and cancer cell lines. This aberrant expression was closely related with tumor stage and lymph node metastasis. Tumor sample with high CD8+ showed lower NEAT1 expression. In vitro studies displayed that inhibition of NEAT1 with shRNA resulted in suppression of survival and migration/invasion of lung cancer cells. On the other side, NEAT1 was found to promote tumor growth via inhibiting cytotoxic T cell immunity in syngeneic models. Finally, NEAT1 was found to interact with DNMT1, which in turn inhibited P53 and cyclic GMP-AMP synthase stimulator of interferon genes (cGAS/STING) expression. CONCLUSION: Our findings demonstrated that NEAT1 interacted with DNMT1 to regulate cytotoxic T cell infiltration in lung cancer via inhibition of cGAS/STING pathway. The results provided the novel mechanistic insight into the pathogenesis of lung cancer.

Sp1-induced upregulation of the long noncoding RNA TINCR inhibits cell migration and invasion by regulating miR-107/miR-1286 in lung adenocarcinoma.

Long non-coding RNA tissue differentiation-inducing non-protein coding (TINCR) is associated with the carcinogenesis of several cancers. However, little is known about the function and mechanism of TINCR in lung adenocarcinoma (LUAD). Here, we aimed to analyze expression of TINCR and elucidate its mechanistic involvement in the progression of LUAD. The expression of TINCR was investigated according to Gene Expression Profiling Interactive Analysis at first and then detected in 29 LUAD tissues and paired adjacent normal tissues using qRT-PCR. Results indicated that TINCR was evidently downregulated in LUAD. The association between TINCR and clinicopathological parameters was analyzed by Pearson's chi-square test, suggesting TINCR was closely correlated with TNM stage and lymph mode metastasis. Subsequently, the function role of TINCR was examined by gain- and loss-of-function studies in LUAD (A549 and NCI-H292) cells. As analyzed by the scratch wound-healing and transwell assays, results revealed that TINCR suppressed the migration and invasion of A549 and NCI-H292 cells. However, TINCR exerted no effects on the cell proliferation as determined by CCK8 assay. Furthermore, we reported that loss of Sp1 could inhibit TINCR expression. Expressions of miR-107/miR-1286 were detected by qRT-PCR assay in A549 and NCI-H292 cells after TINCR knockdown or overexpression. In addition, the direct binding ability of the predicted miR-107 or miR-1286 binding site on TINCR was validated by luciferase activity assay. Results indicated TINCR could constrain the expression of miR-107/miR-1286, and was a target of them in LUAD cells. Bioinformatics analyses showed that BTRC and RAB14 was the potential target gene of miR-107 and miR-1286, respectively. These data revealed a possible regulatory mechanism in which upregulation of TINCR induced by Sp1 could constrain the migration and invasion through regulating miR-107 or miR-1286 in LUAD cells. Conjointly, our findings provide a valuable insight into the regulatory mechanism of TINCR in LUAD, supportive to its potential of therapeutic target for LUAD patients.