Tryptophanyl-tRNA Synthetase Sensitizes Hormone Receptor-Positive Breast Cancer to Docetaxel-Based Chemotherapy

Diagnostic, prognostic, and immunological roles of CDSN in ovarian cancer

Globally, ovarian cancer (OC) ranks as a principal cause of cancer-related mortality in females. Immunotherapy has revolutionized the treatment of OC, but the efficacy of immunotherapy is often limited by different immune microenvironments. The objective of this research was to pinpoint and validate candidate genes with potential value as diagnostic and prognostic biomarkers and therapeutic targets in OC. Data on genes associated with gene mutation, prognostic survival, and immune infiltration in OC were procured from the Cancer Genome Atlas (TCGA). Gene differential analysis, mutation site analysis, prognosis and survival analysis, and functional and signaling pathway enrichment analysis were conducted to identify and evaluate key genes. The genes were further investigated using immune infiltration analysis, receiver operating characteristic curves, and immunohistochemistry. The impact of CDSN on OC cell proliferation was investigated utilizing CCK-8, colony formation, and apoptosis detection assays. We identified a set of genes (CDSN, WARS, and CD38) that were highly expressed in OC and significantly associated with mutations and prognosis. Immune infiltration analysis and immunohistochemistry results indicated a correlation with immune infiltration in the tumor microenvironment, particularly in antigen-presenting cells. Receiver operating characteristic curve analysis demonstrated the diagnostic potential of these three genes in OC, with all three genes showing the area under the curve (AUC) above 0.8. In vitro studies suggested that knocked down CDSN expression resulted in a marked lower in the proliferative capacity of OC cells. The candidate gene CDSN identified through bioinformatics analysis and in vitro experiments is associated with mutation and immune infiltration, showing promise as a diagnostic and prognostic biomarker, as well as a therapeutic objective in OC.

Tryptophanyl-tRNA synthetase-1 (WARS-1) depletion and high tryptophan concentration lead to genomic instability in Caenorhabditis elegans

The fidelity of translation is ensured by a family of proteins named aminoacyl-tRNA synthetases (ARSs), making them crucial for development and survival. More recently, mutations in the tryptophanyl-tRNA synthetase 1 (WARS1) have been linked to various human diseases, from intellectual disability to various types of cancer. To understand the function of WARS1, we investigated the effect of WARS-1 depletion during the mitotic and meiotic cell cycle in the developing germline of Caenorhabditis elegans (C. elegans) and demonstrated the role of WARS-1 in genome integrity. wars-1 knockdown results in cell cycle arrest of the mitotically active germ cells. Such mitotic arrest is also associated with canonical DNA damage-induced checkpoint signaling in mitotic and meiotic germ cells. Significantly, such DNA checkpoint activation is associated with the morphological anomalies in chromatin structures that are the hallmarks of genome instability, such as the formation of chromatin bridges, micronuclei, and chromatin buds. We demonstrated that knocking down wars-1 results in an elevation of the intracellular concentration of tryptophan and its catabolites, a surprising finding emphasizing the impact of cellular amino acid availability and organismal/individual dietary uptake on genome integrity. Our result demonstrates that exposing C. elegans to a high tryptophan dosage leads to DNA damage checkpoint activation and a significant increase in the tryptophan metabolites. Targeting tryptophan catabolism, the least utilized amino acid in nature, can be important in developing new cancer therapeutic approaches. All in all, we have strong evidence that knocking down wars-1 results in defects in genomic integrity.

Nicotinamide (niacin) supplement increases lipid metabolism and ROS‐induced energy disruption in triple‐negative breast cancer: potential for drug repositioning as an anti‐tumor agent

Metabolic dysregulation is an important hallmark of cancer. Nicotinamide (NAM), a water‐soluble amide form of niacin (vitamin B3), is currently available as a supplement for maintaining general physiologic functions. NAM is a crucial regulator of mitochondrial metabolism and redox reactions. In this study, we aimed to identify the mechanistic link between NAM‐induced metabolic regulation and the therapeutic efficacy of NAM in triple‐negative breast cancer (TNBC). The combined analysis using multiomics systems biology showed that NAM decreased mitochondrial membrane potential and ATP production, but increased the activities of reverse electron transport (RET), fatty acid β‐oxidation and glycerophospholipid/sphingolipid metabolic pathways in TNBC, collectively leading to an increase in the levels of reactive oxygen species (ROS). The increased ROS levels triggered apoptosis and suppressed tumour growth and metastasis of TNBC in both human organoids and xenograft mouse models. Our results showed that NAM treatment leads to cancer cell death in TNBC via mitochondrial dysfunction and activation of ROS by bifurcating metabolic pathways (RET and lipid metabolism); this provides insights into the repositioning of NAM supplement as a next‐generation anti‐metabolic agent for TNBC treatment.

tRNA modifications and their potential roles in pancreatic cancer

Since the breakthrough discovery of N6-methyladenosine (m⁶A), the field of RNA epitranscriptomics has attracted increasing interest in the biological sciences. Transfer RNAs (tRNAs) are extensively modified, and various modifications play a crucial role in the formation and stability of tRNA, which is universally required for accurate and efficient functioning of tRNA. Abnormal tRNA modification can lead to tRNA degradation or specific cleavage of tRNA into fragmented derivatives, thus affecting the translation process and frequently accompanying a variety of human diseases. Increasing evidence suggests that tRNA modification pathways are also misregulated in human cancers. In this review, we summarize tRNA modifications and their biological functions, describe the type and frequency of tRNA modification alterations in cancer, and highlight variations in tRNA-modifying enzymes and the multiple functions that they regulate in different types of cancers. Furthermore, the current implications and the potential role of tRNA modifications in the progression of pancreatic cancer are discussed. Collectively, this review describes recent advances in tRNA modification in cancers and its potential significance in pancreatic cancer. Further study of the mechanism of tRNA modifications in pancreatic cancer may provide possibilities for therapies targeting enzymes responsible for regulating tRNA modifications in pancreatic cancer.