Search Results (4,843)

Alkyladenine DNA glycosylase (AAG) is a critical enzyme in the base excision repair (BER) pathway, responsible for removing a broad spectrum of alkylated DNA lesions. While AAG maintains genomic stability, dysregulated activity has been implicated in cancer development, drug resistance, and neurodegenerative diseases. This review synthesizes the current knowledge on AAG’s structure, catalytic mechanism, and polymorphic variants, highlighting their potential roles in disease pathogenesis. A comprehensive bioinformatics analysis of over 370 AAG single-nucleotide polymorphisms (SNPs) is presented, identifying ~40% as high-risk variants likely to impair enzymatic function. Notably, 151 SNPs were predicted to be damaging by multiple algorithms, including substitutions at catalytic residues and non-conserved sites with unknown functional consequences. Analysis of cancer databases (COSMIC, cBioPortal, NCBI) revealed 93 tumor-associated AAG variants, with 18 classified as high-impact mutations. This work underscores the need for mechanistic studies of AAG variants using structural biology, cellular models, and clinical correlation analyses. Deciphering AAG’s polymorphic landscape may unlock personalized strategies for cancer prevention and treatment. Full article

Motor Neuron Diseases (MNDs) such as Amyotrophic Lateral Sclerosis (ALS), Primary Lateral Sclerosis (PLS), Hereditary Spastic Paraplegia (HSP), Spinal Muscular Atrophy with Respiratory Distress Type 1 (SMARD1), Multisystem Proteinopathy (MSP), Spinal and Bulbar Muscular Atrophy (SBMA), and ALS associated to Frontotemporal Dementia (ALS-FTD), have traditionally been studied as distinct entities, each one with unique genetic and clinical characteristics. However, emerging research reveals that these seemingly disparate conditions converge on shared molecular mechanisms that drive progressive neuroaxonal degeneration. This narrative review addresses a critical gap in the field by synthesizing the most recent findings into a comprehensive, cross-disease mechanisms framework. By integrating insights into RNA dysregulation, protein misfolding, mitochondrial dysfunction, DNA damage, kinase signaling, axonal transport failure, and immune activation, we highlight how these converging pathways create a common pathogenic landscape across MNDs. Importantly, this perspective not only reframes MNDs as interconnected neurodegenerative models but also identifies shared therapeutic targets and emerging strategies, including antisense oligonucleotides, autophagy modulators, kinase inhibitors, and immunotherapies that transcend individual disease boundaries. The diagnostic and prognostic potential of Neurofilament Light Chain (NfL) biomarkers is also emphasized. By shifting focus from gene-specific to mechanism-based approaches, this paper offers a much-needed roadmap for advancing both research and clinical management in MNDs, paving the way for cross-disease therapeutic innovations. Full article

Background/Objectives: The breast cancer susceptibility gene 1 (BRCA1) is a tumor suppressor gene whose mutations are associated with increased susceptibility to develop breast or ovarian cancer. BRCA1 mainly exerts its protective effects through DNA double-strand break repair. Although not itself a transcriptional factor, BRCA1, through its multiple protein interaction domains, exerts transcriptional coregulation. In addition, BRCA1 expression alters cellular metabolism including inhibition of de novo fatty acid synthesis, changes in cellular bioenergetics, and activation of antioxidant defenses. Some of these actions may contribute to its global oncosuppressive effects. However, the breadth of metabolic pathways reprogrammed by BRCA1 is not fully elucidated. Methods: Breast cancer cells expressing BRCA1 were investigated by multiplatform metabolomics, metabolism-related transcriptomics, and joint metabolomics/transcriptomics data processing techniques, namely two-way orthogonal partial least squares and pathway analysis. Results: Joint analyses revealed the most important metabolites, genes, and pathways of metabolic reprogramming in BRCA1-expressing breast cancer cells. The breadth of metabolic reprogramming included fatty acid synthesis, bioenergetics, HIF-1 signaling pathway, antioxidation, nucleic acid synthesis, and other pathways. Among them, rewiring of glycerophospholipid (including phosphatidylcholine, -serine and -inositol) metabolism and increased arginine metabolism have not been reported yet. Conclusions: Rewired glycerophospholipid and arginine metabolism were identified as components of BRCA1-induced metabolic reprogramming in breast cancer cells. The study helps to identify metabolites that are candidate biomarkers of the BRCA1 genotype and metabolic pathways that can be exploited in targeted therapies. Full article

Skin aging is closely related to mitochondrial dysfunction and cell cycle abnormalities, and developing intervention strategies targeting mitochondrial quality control is an important direction for anti-aging research. In this study, we investigated the anti-aging mechanism of Camellia japonica flower (CJF) extract and its active ingredient hyperoside based on a doxorubicin (DOX)-induced endogenous senescence model in human skin fibroblasts (HSFs). LC-MS proteomics analysis revealed that CJF extract and hyperoside specifically activated the FUNDC1-mediated mitochondrial autophagy pathway, significantly ameliorated the DOX-induced decrease in mitochondrial membrane potential and the accumulation of reactive oxygen species (ROS), and alleviated the cellular S-phase blockade and reversed the high expression of senescence-associated β-galactosidase (SA-β-gal). Further studies showed that the two cleared damaged mitochondria by enhancing mitochondrial autophagy and restoring cellular energy metabolism homeostasis while promoting type III collagen and elastin synthesis and repairing the expression of Claudin 1 related to skin barrier function. For the first time, the present study reveals the molecular mechanism of CJF extract in delaying skin aging by regulating the FUNDC1-dependent mitochondrial autophagy pathway, which provides a theoretical basis and a candidate strategy for developing novel anti-aging agents targeting mitochondrial quality control. Full article

Background/Objectives: The Fanconi anemia (FA) pathway is essential for the repair of DNA interstrand crosslinks and maintenance of genomic stability. Germline loss of FA pathway function in the inherited Fanconi anemia syndrome leads to increased DNA damage and a range of clinical phenotypes, including a heightened risk of head and neck squamous cell carcinoma (HNSCC). Non-synonymous FA gene mutations are also observed in up to 20% of sporadic HNSCCs. The mechanistic target of rapamycin (mTOR) is known to stimulate cell growth, anabolic metabolism including protein synthesis, and survival following genotoxic stress. Methods/Results: Here, we demonstrate that FA− deficient (FA−) HNSCC cells exhibit elevated intracellular amino acid levels, increased total protein content, and an increase in protein synthesis indicative of enhanced translation. These changes are accompanied by hyperactivation of the mTOR effectors translation initiation factor 4E Binding Protein 1 (4E-BP1) and ribosomal protein S6. Treatment with the mTOR inhibitor rapamycin reduced the phosphorylation of these targets and blocked translation specifically in FA− cells but not in their isogenic FA− proficient (FA+) counterparts. Rapamycin-mediated mTOR inhibition sensitized FA− but not FA+ cells to rapamycin under nutrient stress, supporting a therapeutic metabolism-based vulnerability in FA− cancer cells. Conclusions: These findings uncover a novel role for the FA pathway in suppressing mTOR signaling and identify mTOR inhibition as a potential strategy for targeting FA− HNSCCs. Full article

Human colorectal cancer (CRC) encompasses tumors affecting a segment of the large intestine (colon) and rectum. It is the third most commonly diagnosed malignancy and the second leading cause of cancer deaths worldwide. It is a multifactorial disease, whose carcinogenesis process involves genetic and epigenetic alterations in oncogenes and tumor suppressor genes, including genes related to DNA repair. The pathogenic mechanisms are described based on the pathways of chromosomal instability, microsatellite instability, and CpG island methylator phenotype. When detected early, CRC is potentially curable, and its treatment is based on the pathological characteristics of the tumor and factors related to the patient, as well as on drug efficacy and toxicity studies. Therefore, the aim of this study was to review the pathogenesis and molecular subtypes of CRC and to describe the main targets of disease-directed therapy used in patients refractory to current treatments. Full article

Oxidative stress is a defining and pervasive driver of neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS). As a molecular accelerant, reactive oxygen species (ROS) and reactive nitrogen species (RNS) compromise mitochondrial function, amplify lipid peroxidation, induce protein misfolding, and promote chronic neuroinflammation, creating a positive feedback loop of neuronal damage and cognitive decline. Despite its centrality in promoting disease progression, attempts to neutralize oxidative stress with monotherapeutic antioxidants have largely failed owing to the multifactorial redox imbalance affecting each patient and their corresponding variation. We are now at the threshold of precision redox medicine, driven by advances in syndromic multi-omics integration, Artificial Intelligence biomarker identification, and the precision of patient-specific therapeutic interventions. This paper will aim to reveal a mechanistically deep assessment of oxidative stress and its contribution to diseases of neurodegeneration, with an emphasis on oxidatively modified proteins (e.g., carbonylated tau, nitrated α-synuclein), lipid peroxidation biomarkers (F2-isoprostanes, 4-HNE), and DNA damage (8-OHdG) as significant biomarkers of disease progression. We will critically examine the majority of clinical trial studies investigating mitochondria-targeted antioxidants (e.g., MitoQ, SS-31), Nrf2 activators (e.g., dimethyl fumarate, sulforaphane), and epigenetic reprogramming schemes aiming to re-establish antioxidant defenses and repair redox damage at the molecular level of biology. Emerging solutions that involve nanoparticles (e.g., antioxidant delivery systems) and CRISPR (e.g., correction of mutations in SOD1 and GPx1) have the potential to transform therapeutic approaches to treatment for these diseases by cutting the time required to realize meaningful impacts and meaningful treatment. This paper will argue that with the connection between molecular biology and progress in clinical hyperbole, dynamic multi-targeted interventions will define the treatment of neurodegenerative diseases in the transition from disease amelioration to disease modification or perhaps reversal. With these innovations at our doorstep, the future offers remarkable possibilities in translating network-based biomarker discovery, AI-powered patient stratification, and adaptive combination therapies into individualized/long-lasting neuroprotection. The question is no longer if we will neutralize oxidative stress; it is how likely we will achieve success in the new frontier of neurodegenerative disease therapies. Full article

Background: Blue light (BL) irradiation has been shown to induce photobiomodulation (PBM) in cells. Here, we investigate its influence on cell types involved in wound healing. Methods: Cellular responses of immortalized human keratinocytes (HaCaTs), normal human dermal fibroblasts (NHDFs), and human umbilical vein endothelial cells (HUVECs) after light treatment at 450 nm were analyzed by kinetic assays on cell viability, proliferation, ATP quantification, migration assay, and apoptosis assay. Gene expression was evaluated by transcriptome analysis. Results: A biphasic effect was observed on HaCaTs, NHDFs, and HUVECs. Low-fluence (4.5 J/cm²) irradiation stimulated cell viability, proliferation, and migration. mRNA sequencing indicated involvement of transforming growth factor beta (TGF-β), ErbB, and vascular endothelial growth factor (VEGF) pathways. High-fluence (18 J/cm²) irradiation inhibited these cellular activities by downregulating DNA replication, the cell cycle, and mismatch repair pathways. Conclusions: HaCaTs, NHDFs, and HUVECs exhibited a dose-dependent pattern after BL irradiation. These findings broaden the view of PBM following BL irradiation of these three cell types, thereby promoting their potential application in wound healing and angiogenesis. Our data on low-fluence BL at 450 nm indicates clinical potential for a novel modality in wound therapy. Full article

Head and neck squamous cell carcinomas (HNSCCs) represent a heterogeneous group of tumors with a complex molecular profile. Despite therapeutic advances, patient prognosis remains poor, emphasizing the need for more effective treatment strategies. Traditional chemotherapy, with cisplatin and 5-fluorouracil (5-FU), remains the gold standard but is limited by toxicity and tumor resistance. Immunotherapy, particularly immune checkpoint inhibitors targeting programmed cell death protein 1 (PD-1) and its ligand (PD-L1), has improved overall survival, especially in patients with high PD-L1 expression. In parallel, targeted therapies such as poly (ADP-ribose) polymerase 1 (PARP1) inhibitors—which impair DNA repair and increase replication stress—have shown promising activity in HNSCC. Cyclin-dependent kinase (CDK) inhibitors are also under investigation due to their potential to correct dysregulated cell cycle control, a hallmark of HNSCC. This review aims to summarize current and emerging pharmacotherapies for HNSCC, focusing on chemotherapy, immunotherapy, and PARP and CDK inhibitors. It also discusses the evolving role of targeted therapies in improving clinical outcomes. Future research directions include combination therapies, nanotechnology-based delivery systems to enhance treatment specificity, and the development of diagnostic tools such as PARP1-targeted imaging to better guide personalized treatment approaches. Full article

DNA connects the domains of genetic regulation and environmental interactions and plays a crucial role in neural development and cognitive function. The complex roles of genetic and epigenetic processes in brain development, synaptic plasticity, and higher-order cognitive abilities were reviewed in this study. Neural progenitors are formed and differentiated according to genetic instructions, whereas epigenetic changes, such as DNA methylation, dynamically control gene expression in response to external stimuli. These processes shape behavior and cognitive resilience by influencing neural identity, synaptic efficiency, and adaptation. This review also examines how DNA damage and repair mechanisms affect the integrity of neurons, which are essential for memory and learning. It also emphasizes how genetic predispositions and environmental factors interact to determine a person’s susceptibility to neurodegenerative disorders, such as Parkinson’s and Alzheimer’s diseases. Developments in gene-editing technologies, such as CRISPR, and non-viral delivery techniques provide encouraging treatment avenues for neurodegenerative disorders. This review highlights the fundamental role of DNA in coordinating the intricate interactions between molecular and environmental factors that underlie brain function and diseases. Full article

The incorporation of nucleoside analogs into DNA by polymerases, followed by their removal through base excision repair (BER), represents a promising strategy for cancer chemotherapy. In this study, we investigated the incorporation and cytotoxic effects of several nucleoside analogs—some of which are epigenetic reprogramming intermediates—in the U87 glioblastoma cell line. We found that two analogs, 5-hydroxymethyl-2′-deoxyuridine (5HmdU) and trifluorothymidine (TFT), are both cytotoxic and are efficiently incorporated into genomic DNA. In contrast, the 5-carboxy analogs—5-carboxy-2′-deoxyuridine (5CadU) and 5-carboxycytidine (5CadC)—showed no cytotoxicity and were not incorporated into DNA. Interestingly, 5-hydroxymethyl-2′-deoxycytidine (5HmdC) was cytotoxic but was not directly incorporated into DNA. Instead, it was deaminated into 5HmdU, which was then incorporated and likely responsible for the observed toxicity. 5HmdU is actively removed from DNA through the BER pathways. In contrast, TFT remains stably incorporated and is neither excised by BER nor does it hydrolyze into 5CadU—a known substrate for the DNA glycosylase SMUG1. We also found that N⁶-benzyladenosine (BzAdo), an inhibitor of the enzyme 2′-deoxynucleoside 5′-phosphate N-hydrolase (DNPH1), enhances the cytotoxicity of 5HmdU. However, the thymidine phosphorylase inhibitor tipiracil hydrochloride (TPI) does not increase the cytotoxic effect of TFT in U87 cells. Together, these findings highlight 5HmdU and TFT as promising chemotherapeutic agents for glioblastoma, each with distinct mechanisms of action and cellular processing. Full article

The ataxia–telangiectasia-mutated (ATM) protein plays a crucial role in the DNA damage response, particularly in the homologous recombination (HR) pathway. This study aimed to assess the impact of deleterious ATM variants on homologous recombination deficiency (HRD) and response to PARP inhibitors (PARPi) in melanoma patients, using a cell line established from melanoma tissue of a patient carrying the c.5979_5983del germline ATM variant. Despite proven loss of heterozygosity, lack of ATM activation, and HRD, our model did not show sensitivity to PARPi. We assessed the potential contribution of the Schlafen family member 11 (SLFN11) helicase, whose expression is inversely correlated with PARPi sensitivity in other cancers, to the observed resistance. The ATM mutant cell line lacked SLFN11 expression and featured hypermethylation-mediated silencing of the SLFN11 promoter. While sensitive to the ATR inhibitor (ATRi), the addition of ATRi to PARPi was unable to overcome the resistance. Our findings suggest that ATM mutational status and HRD alone do not adequately account for variations in sensitivity to PARPi in our model. A comprehensive approach is essential for optimizing the exploitation of DNA repair defects and ultimately improving clinical outcomes for melanoma patients. Full article

Vibrio parahaemolyticus is a major foodborne pathogen worldwide, responsible for seafood-associated poisoning. Among its toxin genes, tdh2 is the most critical. To investigate the role of tdh2 in V. parahaemolyticus under gastrointestinal conditions, we constructed tdh2 deletion and complementation strains and compared their survival under acid (pH 3 and 4) and bile stress (2%). The results showed that tdh2 expression was significantly upregulated under cold (4 °C) and bile stress (0.9%). Survival assays and PI staining revealed that the tdh2 mutant strain (VP: △tdh2) was more sensitive to acid and bile stress than the wild-type (WT), and this sensitivity was rescued by tdh2 complementation. These findings suggest that tdh2 plays a protective role in enhancing V. parahaemolyticus tolerance to acid and bile stress. In the VP: △tdh2 strain, seven genes were significantly upregulated and six were downregulated as a result of tdh2 deletion. These genes included VPA1332 (vtrA), VPA1348 (vtrB), VP2467 (ompU), VP0301 and VP1995 (ABC transporters), VP0527 (nhaR), and VP2553 (rpoS), among others. Additionally, LC-MS/MS analysis identified 12 differential metabolites between the WT and VP: △tdh2 strains, including phosphatidylserine (PS) (17:2 (9Z,12Z) /0:0 and 20:1 (11Z) /0:0), phosphatidylglycerol (PG) (17:0/0:0), flavin mononucleotide (FMN), and various nucleotides. The protective mechanism of tdh2 may involve preserving cell membrane permeability through regulation of ompU and ABC transporters and enhancing electron transfer efficiency via regulation of nhaR. The resulting reduction in ATP, DNA, and RNA synthesis—along with changes in membrane permeability and electron transfer due to decreased FMN—likely contributed to the reduced survival of the VP: △tdh2 strain. Meanwhile, the cells actively synthesized phospholipids to repair membrane damage, leading to increased levels of PS and PG. This study provides important insights into strategies for preventing and controlling food poisoning caused by tdh⁺ V. parahaemolyticus. Full article

The American Cancer Society estimates that over 152,000 new cases of colorectal cancer (CRC) were diagnosed in 2024, with more than 105,000 cases affecting the colon and 46,000 involving the rectum. CRC remains the second leading cause of cancer-related deaths in the United States, with an estimated 53,010 deaths in 2024. In the era of precision medicine, which incorporates molecular and environmental information into clinical decision-making, identifying patients harboring a deficiency in Deoxyribonucleic acid (DNA) repair allowed for targeted immunotherapies and significantly reduced CRC-related mortality. A significant advancement in this domain is the application of liquid biopsy, which has emerged as a promising tool for prognostication, guiding therapy, and monitoring treatment response in CRC. This review aims to comprehensively explore the role of liquid biopsy in colorectal malignancies, describing its practical applications, prognostic significance, and potential to revolutionize CRC management in the future. At the end, we also aim to show a schematic representation of showing integration of Circulating Tumor (Ct) DNA in routine clinical management of CRC. The highlight of this article is the structured and evidence-based schematic framework and its integration into future practice. The schematic pathway is designed to optimize ctDNA utilization across various stages of colorectal cancer management. Full article

DNA damage repair is a hallmark of any cancer growth, eventually leading to drug resistance and death. The poly ADP-ribose polymerase (PARP) enzyme is vital in repairing damaged DNA in normal and cancer cells with mutated DNA damage response (DDR) genes. Inhibitors of the PARP enzyme aid in chemotherapy, as shown by drug combinations such as Olaparib and Irinotecan in breast cancer treatment. However, the effect of Olaparib in colon cancer has not been studied extensively. Synthetic drugs have a significant limitation in cancer treatment due to drug resistance, leading to colon cancer relapse. Bioavailability of Olaparib and other PARP inhibitors is limited due to their hydrophobicity, which poses a significant challenge. These limitations and challenges can be addressed by encapsulating Olaparib in nanoparticles that could possibly increase the bioavailability of the drug at the site of action. New age nanoparticles, such as hybrid nanoparticles, provide superior quality in terms of design and circulatory time of the drug in the plasma. The side effects of Olaparib as a chemotherapeutic pave the way for exploring phytochemicals that may have similar effects. The combined impact of Olaparib and phytochemicals such as genistein, resveratrol and others in nano-encapsulated form can be explored in the treatment of colon cancer. Full article