miRNA-193b-5p Suppresses Pancreatic Cancer Cell Proliferation, Invasion, Epithelial Mesenchymal Transition, and Tumor Growth by Inhibiting eEF2K

Targeting eukaryotic elongation factor 2 kinase (eEF2K) with small-molecule inhibitors for cancer therapy

Eukaryotic elongation factor 2 kinase (eEF2K) is a member of the α-kinase family that is activated by calcium/calmodulin. Of note, eEF2K is crucial for regulating translation and is often highly overexpressed in malignant cells. Therefore in this review, we summarize the molecular structure of eEF2K and its oncogenic roles in cancer. Moreover, we further discuss the inhibition of eEF2K with small-molecule inhibitors and other new emerging therapeutic strategies in cancer therapy. Taken together, these inspiring findings provide new insights into a promising strategy for inhibiting eEF2K to greatly improve future cancer therapy.

Tight Junctions and Cancer: Targeting Claudin-1 and Claudin-4 in Thyroid Pathologies

Purpose: Claudins are tight junction proteins partaking in epithelial-mesenchymal transition and cancer progression. In this study, we investigated the expression patterns of claudin-1 and claudin-4 in thyroid pathologies, discussed their links with the pathogenesis of thyroid cancers, and reviewed the therapeutic potential of targeting claudins in cancers. Methods: The research group 162 cores of thyroid samples from patients (70 female and 11 male) diagnosed with thyroid adenoma, goiter, papillary, medullary, and anaplastic thyroid cancers. All samples were stained for the expression of claudin-1 and claudin-4, and the analysis of IHC was performed. Results: Goiter samples showed negative claudin-1 and mostly positive expression of claudin-4. Papillary thyroid cancer and thyroid adenoma showed positive expression of claudin-1, while claudin-4 was positive in papillary thyroid cancers, goiters, and adenomas. In The Cancer Genome Atlas cohort, claudin-1 and claudin-4 were overexpressed in papillary thyroid cancer compared to normal thyroid tissues. Patients with high claudin-1 expression had significantly lower 5-year overall survival than patients with low claudin-1 levels (86.75% vs. 98.65, respectively). In multivariate analysis, high claudin-1 expression (HR 7.91, CI 95% 1.79-35, p = 0.006) and advanced clinical stage remained statistically significant prognostic factors of poor prognosis in papillary thyroid cancer. Conclusions: The pattern of claudin-1 staining was pathology-specific and changed between cancers of different histology. This phenomenon may be associated with the different pathogenesis of thyroid cancers and early metastasis. The loss of claudin-1 and claudin-4 characterized more aggressive cancers. Several studies have shown the benefits of targeting claudins in cancers, but their implementation into clinical practice requires further trials.

Claudins: from gatekeepers of epithelial integrity to potential targets in hepato-pancreato-biliary cancers

Claudins, a family of tetraspan transmembrane proteins, are critical to the integrity of tight junctions in epithelia and endothelia, influencing cellular processes such as development, differentiation, and apoptosis. Abnormal claudin expression is associated with various malignancies, particularly affecting tissue architecture and potentially facilitating tumor invasion and metastasis. In this comprehensive review, we explore the multifaceted functions of claudins: their expression, specific roles in cancer with a focus on hepato-pancreato-biliary malignancies and highlight their potential as therapeutic targets. We discuss current claudin-targeted therapies, including monoclonal antibodies, antibody-drug conjugates, bispecific T-cell engager and chimeric antigen receptor T-cell therapies. These approaches show promise in pre-clinical and clinical studies, particularly in hepato-pancreato-biliary cancers with large unmet needs. Despite these early signs of efficacy, challenges remain in effectively targeting these proteins due to their structural resemblance and overlapping functions.

Expression and Targeted Application of Claudins Family in Hepatobiliary and Pancreatic Diseases

Hepatobiliary and pancreatic diseases are becoming increasingly common worldwide and associated cancers are prone to recurrence and metastasis. For a more accurate treatment, new therapeutic strategies are urgently needed. The claudins (CLDN) family comprises a class of membrane proteins that are the main components of tight junctions, and are essential for forming intercellular barriers and maintaining cellular polarity. In mammals, the claudin family contains at least 27 transmembrane proteins and plays a major role in mediating cell adhesion and paracellular permeability. Multiple claudin proteins are altered in various cancers, including gastric cancer (GC), esophageal cancer (EC), hepatocellular carcinoma (HCC), pancreatic cancer (PC), colorectal cancer (CRC) and breast cancer (BC). An increasing number of studies have shown that claudins are closely associated with the occurrence and development of hepatobiliary and pancreatic diseases. Interestingly, claudin proteins exhibit different effects on cancer progression in different tumor tissues, including tumor suppression and promotion. In addition, various claudin proteins are currently being studied as potential diagnostic and therapeutic targets, including claudin-3, claudin-4, claudin-18.2, etc. In this article, the functional phenotype, molecular mechanism, and targeted application of the claudin family in hepatobiliary and pancreatic diseases are reviewed, with an emphasis on claudin-1, claudin-4, claudin-7 and claudin-18.2, and the current situation and future prospects are proposed.

MicroRNAs: emerging biomarkers and therapeutic targets in pancreatic cancer

Pancreatic cancer (PC) is a highly malignant disease with high aggressiveness and a dismal prognosis, which is challenging to diagnose clinically early and gains low benefit from standard therapies. MicroRNAs (miRNAs) have become a hot topic in oncology research. Current evidence indicates that miRNAs are regulators involved in the entire process of PC, providing new diagnostic and therapeutic strategies for this fatal disease. Related research has been rapidly updated, making it necessary to review it to propose new directions and ideas and provide guidance for the development of precision medicine for PC. We reviewed the relevant literature through Pubmed, Embase, Web of Science and Medline, showing that abnormally expressed miRNAs in PC patients have the potential to be used as biomarkers for diagnosis and prognosis, highlighting the excellent prospect of combining miRNAs with traditional therapies, and the effective application of these factors for PC, especially miRNA mimics and inhibitors. MiRNAs participate in the entire process of PC and play important roles in diagnosis, treatment and prognosis. They are potential factors in conquering PC in the future.

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

BACKGROUND

Liver cancer, particularly hepatocellular carcinoma (HCC), is characterized by a high mortality rate, attributed primarily to the establishment of an immunosuppressive microenvironment. Within this context, we aimed to elucidate the pivotal role of eukaryotic elongation factor 2 kinase (eEF2K) in orchestrating the infiltration and activation of natural killer (NK) cells within the HCC tumor microenvironment. By shedding light on the immunomodulatory mechanisms at play, our findings should clarify HCC pathogenesis and help identify potential therapeutic intervention venues.

METHODS

We performed a comprehensive bioinformatics analysis to determine the functions of eEF2K in the context of HCC. We initially used paired tumor and adjacent normal tissue samples from patients with HCC to measure eEF2K expression and its correlation with prognosis. Subsequently, we enrolled a cohort of patients with HCC undergoing immunotherapy to examine the ability of eEF2K to predict treatment efficacy. To delve deeper into the mechanistic aspects, we established an eEF2K-knockout cell line using CRISPR/Cas9 gene editing. This step was crucial for verifying activation of the cGAS-STING pathway and the subsequent secretion of cytokines. To further elucidate the role of eEF2K in NK cell function, we applied siRNA-based techniques to effectively suppress eEF2K expression in vitro. For in vivo validation, we developed a tumor-bearing mouse model that enabled us to compare the infiltration and activation of NK cells within the tumor microenvironment following various treatment strategies.

RESULTS

We detected elevated eEF2K expression within HCC tissues, and this was correlated with an unfavorable prognosis (30.84 vs. 20.99 months, P = 0.033). In addition, co-culturing eEF2K-knockout HepG2 cells with dendritic cells led to activation of the cGAS-STING pathway and a subsequent increase in the secretion of IL-2 and CXCL9. Moreover, inhibiting eEF2K resulted in notable NK cell proliferation along with apoptosis reduction. Remarkably, after combining NH125 and PD-1 treatments, we found a significant increase in NK cell infiltration within HCC tumors in our murine model. Our flow cytometry analysis revealed reduced NKG2A expression and elevated NKG2D expression and secretion of granzyme B, TNF-α, and IFN-γ in NK cells. Immunohistochemical examination confirmed no evidence of damage to vital organs in the mice treated with the combination therapy. Additionally, we noted higher levels of glutathione peroxidase and lipid peroxidation in the peripheral blood serum of the treated mice.

CONCLUSION

Targeted eEF2K blockade may result in cGAS-STING pathway activation, leading to enhanced infiltration and activity of NK cells within HCC tumors. The synergistic effect achieved by combining an eEF2K inhibitor with PD-1 antibody therapy represents a novel and promising approach for the treatment of HCC.

Claudin and pancreatic cancer

Due to the lack of timely and accurate screening modalities and treatments, most pancreatic cancer (PCa) patients undergo fatal PCa progression within a short period since diagnosis. The claudin(CLDN) family is expressed specifically as tight junction structure in a variety of tumors, including PCa, and affects tumor progression by changing the cell junctions. Thus far, many of the 27 members of the claudin family, including claudin-18.2 and claudin-4, have significantly aberrantly expression in pancreatic tumors. In addition, some studies have confirmed the role of some claudin proteins in the diagnosis and treatment of pancreatic tumors. By targeting different targets of claudin protein and combining chemotherapy, further enhance tumor cell necrosis and inhibit tumor invasion and metastasis. Claudins can either promote or inhibit the development of pancreatic cancer, which indicates that the diagnosis and treatment of different kinds of claudins require to consider different biological characteristics. This literature summarizes the functional characteristics and clinical applications of various claudin proteins in Pca cells, with a focus on claudin-18.2 and claudin-4.