Clinical significance of STING expression and methylation in lung adenocarcinoma based on bioinformatics analysis

Prognostic and immunological significance of metastasis-associated protein 3 in patients with thymic epithelial tumors

BACKGROUND

Immune checkpoint inhibitors have shown promising anticancer activity and have recently been proposed as a therapy for thymic epithelial tumors (TETs); however, this treatment is only effective for a subgroup of TET patients. Thus, this study aims to identify the potential genes implicated in the regulation of cancer immunity in TETs.

METHODS

The TETs RNA-seq and clinical data were obtained from The Cancer Genome Atlas (TCGA) database. The clinical significance of the tumor microenvironment (TME) in TETs was evaluated. Weighted gene coexpression network analysis (WGCNA) was used to identify the immune response-related hub genes. The expression of metastasis-associated protein 3 (MTA3) in TETs was investigated in public datasets and a patient cohort. Kaplan‒Meier curves were generated to analyze the prognostic value of various factors. The Tumor Immune Estimation Resource (TIMER2.0) was used to estimate the relevance of MTA3 to immune cell infiltration. Gene set enrichment analysis (GSEA) and pathway enrichment analysis were applied to explore the MTA3-related pathways.

RESULTS

The TME was found to be clinically significant in TETs. Moreover, MTA3 was identified as a key gene associated with the immune score, and lower MTA3 expression was linked to poor TME and reduced cytotoxic activity in TETs. Furthermore, MTA3 was found to be deregulated in TETs, predictive of poor prognosis. MTA3 was also significantly associated with the infiltration levels of various immune cell types and highly correlated with their corresponding markers. Notably, MTA3 was positively associated with various immune response pathways.

CONCLUSION

MTA3 is clinically significant in TETs and correlated with immune cell infiltration. Thus, MTA3 might be a biomarker for predicting the prognosis and immune status of TET patients.

Role of STING in the treatment of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is a prevalent form of lung cancer. Patients with advanced NSCLC are currently being treated with various therapies, including traditional radiotherapy, chemotherapy, molecular targeted therapies and immunotherapy. However, a considerable proportion of advance patients who cannot benefit from them. Consequently, it is essential to identify a novel research target that offers an encouraging perspective. The stimulator of interferon genes (STING) has emerged as such a target. At present, it is confirmed that activating STING in NSCLC tumor cells can impede the proliferation and metastasis of dormant tumor cells. This review focuses on the role of STING in NSCLC treatment and the factors influencing its activation. Additionally, it explores the correlation between STING activation and diverse therapy modalities for NSCLC, such as radiotherapy, chemotherapy, molecular targeted therapies and immunotherapy. Furthermore, it proposes the prospect of innovative therapy methods involving nanoparticles, with the aim of using the features of STING to develop more strategies for NSCLC therapy.

The interaction between DNA methylation and tumor immune microenvironment: from the laboratory to clinical applications

DNA methylation is a pivotal epigenetic modification that affects gene expression. Tumor immune microenvironment (TIME) comprises diverse immune cells and stromal components, creating a complex landscape that can either promote or inhibit tumor progression. In the TIME, DNA methylation has been shown to play a critical role in influencing immune cell function and tumor immune evasion. DNA methylation regulates immune cell differentiation, immune responses, and TIME composition Targeting DNA methylation in TIME offers various potential avenues for enhancing immune cytotoxicity and reducing immunosuppression. Recent studies have demonstrated that modification of DNA methylation patterns can promote immune cell infiltration and function. However, challenges persist in understanding the precise mechanisms underlying DNA methylation in the TIME, developing selective epigenetic therapies, and effectively integrating these therapies with other antitumor strategies. In conclusion, DNA methylation of both tumor cells and immune cells interacts with the TIME, and thus affects clinical efficacy. The regulation of DNA methylation within the TIME holds significant promise for the advancement of tumor immunotherapy. Addressing these challenges is crucial for harnessing the full potential of epigenetic interventions to enhance antitumor immune responses and improve patient outcomes.

Cancer cell-specific cGAS/STING Signaling pathway in the era of advancing cancer cell biology

Pattern-recognition receptors (PRRs) are critical to recognizing endogenous and exogenous threats to mount a protective proinflammatory innate immune response. PRRs may be located on the outer cell membrane, cytosol, and nucleus. The cGAS/STING signaling pathway is a cytosolic PRR system. Notably, cGAS is also present in the nucleus. The cGAS-mediated recognition of cytosolic dsDNA and its cleavage into cGAMP activates STING. Furthermore, STING activation through its downstream signaling triggers different interferon-stimulating genes (ISGs), initiating the release of type 1 interferons (IFNs) and NF-κB-mediated release of proinflammatory cytokines and molecules. Activating cGAS/STING generates type 1 IFN, which may prevent cellular transformation and cancer development, growth, and metastasis. The current article delineates the impact of the cancer cell-specific cGAS/STING signaling pathway alteration in tumors and its impact on tumor growth and metastasis. This article further discusses different approaches to specifically target cGAS/STING signaling in cancer cells to inhibit tumor growth and metastasis in conjunction with existing anticancer therapies.