Enhanced NK cell activation via eEF2K-mediated potentiation of the cGAS-STING pathway in hepatocellular carcinoma

Deciphering cGAS-STING signaling: implications for tumor immunity and hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most prevalent form of primary liver cancer and poses a significant global health challenge due to its rising incidence and associated mortality. Recent advancements in understanding the cytosolic DNA sensing, the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway have illuminated its critical role in the immune response to HCC. This narrative review deciphers the multifaceted involvement of cGAS-STING in HCC, mainly its function in detecting cytosolic DNA and initiating type I interferon (IFN-I) responses, which are pivotal for antitumor immunity. This immune response is crucial for combating pathogens and can play a role in tumor surveillance. In the context of HCC, the tumor microenvironment (TME) can exhibit immune resistance, which complicates the effectiveness of therapies like immune checkpoint blockade. However, activation of the cGAS-STING pathway has been shown to stimulate antitumor immune responses, enhancing the activity of dendritic cells and cytotoxic T lymphocytes. There is ongoing research into STING agonists as a treatment strategy for HCC, with some studies indicating promising results in prolonging survival and enhancing the immune response against tumors. By summarizing current knowledge and identifying research gaps, this review aims to provide a comprehensive overview of cGAS-STING signaling in HCC and its future directions, emphasizing its potential as a therapeutic target in the fight against HCC. Understanding these mechanisms could pave the way for innovative immunotherapeutic approaches that enhance the efficacy of existing treatments and improve patient prognosis.

cGAS/STING pathway and gastrointestinal cancer: Mechanisms and diagnostic and therapeutic targets (Review)

The health of individuals is seriously threatened by intestinal cancer, which includes pancreatic, colorectal, esophageal, gastric and gallbladder cancer. Most gastrointestinal cancers do not have typical and specific early symptoms, and lack specific and effective diagnostic markers and treatment methods. It is critical to understand the etiology of gastrointestinal cancer and develop more efficient methods of diagnosis and treatment. The cyclic GMP‑AMP synthase (cGAS)/stimulator of interferon genes (STING) pathway serves a crucial role in the occurrence, progression and treatment of gastrointestinal cancer. The present review focuses on the latest progress regarding the role and mechanism of the cGAS/STING pathway in gastrointestinal cancer, and discusses treatment approaches and related applications based on the cGAS/STING signaling pathway. In order to improve the knowledge of the connection between the cGAS/STING pathway and gastrointestinal cancer, aid the diagnosis and treatment of gastrointestinal cancer, and lessen the burden on patients and society, the present review also discusses future research directions and existing challenges regarding cGAS/STING in the study of gastrointestinal cancer.

eEF-2K Deficiency Boosts the Virus-Specific Effector CD8+ T Cell Responses During Viral Infection

In this study, we revealed a critical role of eukaryotic elongation factor-2 kinase (eEF-2K), a negative regulator of protein synthesis, in regulating T cells during vaccinia virus (VACV) infection. We found that eEF-2K-deficient (eEF-2K⁻/⁻) mice exhibited a significantly higher proportion of VACV-specific effector CD8+ T cells without compromising the development of VACV-specific memory CD8+ T cells. RNA sequencing demonstrated that eEF-2K⁻/⁻ VACV-specific effector CD8+ T cells had enhanced functionality, which improves their capacity to combat viral infection during the effector phase. Moreover, we identified tumor necrosis factor receptor-associated factor 3 (TRAF3) as a critical mediator of the stronger antiviral response observed in eEF-2K⁻/⁻ effector CD8+ T cells. These findings suggest that targeting eEF-2K may provide a novel strategy to augmenting effector CD8+ T cell responses against viral infections.

NK cell-based immunotherapy in hepatocellular carcinoma: An attractive therapeutic option for the next decade

Hepatocellular carcinoma (HCC), a major subtype of liver cancer, poses significant therapeutic challenges due to its late diagnosis and rapid progression. The evolving landscape of immunotherapy offers a beacon of hope, with natural killer (NK) cells emerging as pivotal players in combating HCC. NK cells are unique cytotoxic lymphocytes that are essential in the fight against infections and malignancies. Phenotypic and functional NK cell abnormalities have been shown in HCC patients, indicating their significance as a component of the innate immune system against cancer. This review elucidates the critical role of NK cells in combating HCC, focusing on their interaction with the tumor microenvironment, the development of NK cell-based therapies, and the innovative strategies to enhance their efficacy in the immunosuppressive milieu of HCC. The review delves into the various therapeutic strategies, including autologous and allogeneic NK cell therapies, genetic engineering to improve NK cell resilience and targeting, and the integration of NK cells with other immunotherapeutic approaches like checkpoint inhibitors and oncolytic virotherapy. By highlighting recent advancements and the ongoing challenges in the field, this review sets the stage for future research directions that could unlock the full potential of NK cell-based immunotherapy for HCC, offering a beacon of hope for patients battling this formidable cancer.