Search Results (172)

During the pathological process of spinal cord injury (SCI), ferroptosis is closely related to mitochondrial homeostasis. Following the occurrence of SCI, the interruption of local blood supply leads to mitochondrial damage within cells and a reduction in Adenosine triphosphate (ATP) production. This results in the loss of transmembrane ion gradients, causing an influx of Ca²⁺ into the cells, which in turn generates a significant amount of Reactive oxygen species (ROS) and reactive nitrogen species. This leads to severe mitochondrial dysfunction and an imbalance in mitochondrial homeostasis. Ferroptosis is a form of programmed cell death that differs from other types of apoptosis, as it is dependent on the accumulation of iron and lipid peroxides, along with their byproducts. The double bond structures in intracellular polyunsaturated fatty acids (PUFA) are particularly susceptible to attack by ROS, leading to the formation of lipid alkyl free radicals. This accumulation of lipid peroxides within the cells triggers ferroptosis. After SCI, the triggering of ferroptosis is closely associated with the “death triangle”—a core network that catalyzes cell death through the interaction of three factors: local iron overload, collapse of antioxidant defenses, and dysregulation of PUFA metabolism (where PUFA are susceptible to attack by reactive ROS leading to lipid peroxidation). These three elements interact to form a central network driving cell death. In the pathological cascade of SCI, mitochondria serve as both a major source of ROS and a primary target of their attack, playing a crucial role in the initiation and execution of cellular ferroptosis. Mitochondrial homeostasis imbalance is not only a key inducer of the “death triangle” (such as the intensification of lipid peroxidation by mitochondrial ROS), but is also reverse-regulated by the “death triangle” (such as the destruction of mitochondrial structure by lipid peroxidation products). Through the cascade reaction of this triangular network, mitochondrial homeostasis imbalance and the “death triangle” jointly drive the progression of secondary damage. This study aims to synthesize the mechanisms by which various therapeutic approaches mitigate SCI through targeted regulation of mitochondrial homeostasis and inhibition of ferroptosis. Unlike previous research, we integrate the bidirectional regulatory relationship between “mitochondrial homeostasis disruption” and “ferroptosis” in SCI, and emphasize their importance as a synergistic therapeutic target. We not only elaborate in detail how mitochondrial homeostasis—including biogenesis, dynamics, and mitophagy—modulates the initiation and execution of ferroptosis, but also summarize recent strategies that simultaneously target both processes to achieve neuroprotection and functional recovery. Furthermore, this review highlights the translational potential of various treatments in blocking the pathological cascade driven by oxidative stress and lipid peroxidation. These insights provide a novel theoretical framework and propose combinatory therapeutic approaches, thereby laying the groundwork for designing precise and effective comprehensive treatment strategies for SCI in clinical settings. Full article

Background/Objectives: The conventional treatment of glioblastoma (GBM) with alkylating agents is not curative. The protein O6-methylguanine DNA methyltransferase (MGMT) is a significant limitation, being able to repair drug-induced DNA damage. Thus, exploring non-alkylating agents already approved by the FDA is imperative. The antidepressant fluoxetine (FL) has been explored due to its anti-cancer properties. However, its first-pass effect and its non-targeted distribution to brain tissue are major limitations of FL’s administration, which is conventionally orally administered. Thus, the primary objective of this work was the development of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) tailored with folic acid (FA) for FL delivery to GBM cells. Methods: A Central Composite Design (CCD) was applied to optimize the NPs. Results: The developed FA-functionalized PLGA NPs exhibited physicochemical properties suitable for brain-targeted delivery. The final formulation presented an average diameter of 167 ± 8 nm, a polydispersity index (PdI) of 0.23 ± 0.07, and a zeta potential of −22.2 ± 0.3 mV. The encapsulation efficiency (EE) and loading capacity (LC) values were 44.4 ± 3.8% and 3.1 ± 0.3%, respectively. In vitro studies demonstrated that the NPs are stable in storage and simulated physiological conditions and can maintain a controlled and slow-release profile of FL for 17 days. In vitro cell uptake experiments demonstrated that conjugation with FA enhances the NPs’ internalization in GBM cells overexpressing folate receptors through endocytosis mediated by this receptor. Furthermore, in vitro cytotoxicity experiments demonstrated that the FL encapsulation in the developed NPs maintains drug efficacy, as well as it was able to increase cell sensitivity to treatment with an alkylating agent. Conclusions: These results suggest that the developed NPs are effective nanocarriers, either as a standalone therapy or as a chemosensitizer in combination with the standard GBM treatment. Full article

The expansion of the Alberta Oil Sands Region (AOSR) has increased the deposition of petroleum-derived chemicals into the surrounding environment. Among these, polycyclic aromatic compounds (PACs), including sulfur-containing heterocyclic hydrocarbons, have been detected in exposed local wildlife, yet the reproductive toxicity and genotoxicity of this suite of PACs remain largely unexplored. This study examined the effects of dibenzothiophene (DBT) and its alkylated congener, 2,4,7-trimethyldibenzothiophene (2,4,7-DBT), on estradiol (E2) synthesis and metabolism in granulosa cells (SIGCs). Cells were exposed to DBT or 2,4,7-DBT for 24 h at concentrations detected in AOSR wildlife tissues (0, 0.1, 1 and 10 nM). We measured the gene expression of markers involved in E2 synthesis, signaling and metabolism, E2 output via ELISA and E2 metabolite production via HPLC-MS/MS. Exposure to 2,4,7-DBT, but not DBT, shifted E2 metabolism towards 4-OHE2, a genotoxic E2 metabolite. DNA damage was assessed by γH2Ax expression, alongside DNA repair (Parp1) and survival markers (pAKT). Interestingly, both DBT and 2,4,7-DBT increased DNA damage and triggered apoptosis via a caspase-independent mechanism. Given the critical role of granulosa cells in steroidogenesis and fertility, these findings highlight the endocrine-disruptive effects of sulfur-containing heterocyclic PACs and their potential to compromise reproductive health in exposed mammals. Full article

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

Chemotherapeutic agents and radiotherapy are highly effective in treating malignancies. However, they carry a significant risk of harming the gonads and may lead to endocrine dysfunction and reproductive issues. This review outlines the molecular mechanisms of gonadotoxic therapies, focusing on radiation, alkylating agents, and platinum compounds. It discusses the loss of PMFs due to gonadotoxic exposure, including DNA double-strand breaks, oxidative stress, and dysregulated signaling pathways like PI3K/PTEN/Akt/mTOR and TAp63-mediated apoptosis. Furthermore, it explores strategies to mitigate gonadal damage, including GnRH agonists, AMH, imatinib, melatonin, sphingolipid metabolites, G-CSF, mTOR inhibitors, AS101, and LH. These therapies, paired with existing fertility preservation methods, could safeguard reproductive and hormonal functions and improve the quality of life for young cancer patients. Despite the progress made in recent years in understanding gonadotoxic mechanisms, gaps remain due to questionable reliance on mouse models and the lack of models replicating human ovarian dynamics. Long-term studies are vital for wider analyses and exploration of protective strategies based on various animal models and clinical trials. It is essential to verify that these substances do not hinder the anti-cancer effectiveness of treatments or cause lasting DNA changes in granulosa cells, raising the risk of miscarriages and infertility. Full article

The enzyme ABH2, one of nine human DNA dioxygenases of the AlkB family, belongs to the superfamily of Fe(II)/α-ketoglutarate-dependent dioxygenases and plays a crucial role in the direct reversal repair of nonbulky alkyl lesions in DNA nucleobases. ABH2 has broad substrate specificity, directly oxidizing DNA damages such as N¹-methyladenine, N³-methylcytosine, 1,N⁶-ethenoadenine, 3,N⁴-ethenocytosine, and a number of others. In our investigation, we sought to uncover the subtleties of the mechanisms governing substrate specificity in ABH2 by focusing on several critical amino acid residues situated in its active site. To gain insight into the function of this enzyme, we performed a functional mapping of its active site region, concentrating on pivotal residues, participating in forming a damaged binding pocket of the enzyme (Val99 and Ser125), as well as the residues directly involved in interactions with damaged bases, namely Arg110, Phe124, Arg172, and Glu175. To support our experimental data, we conducted a series of molecular dynamics simulations, exploring the interactions between the ABH2 mutant forms, bearing corresponding substitutions and DNA substrates, and harboring various types of methylated bases, specifically N¹-methyladenine or N³-methylcytosine. The comparative studies revealed compelling data indicating that alterations in most of the studied amino acid residues significantly influence both the binding affinity of the enzyme for DNA and its catalytic efficiency. Intriguingly, the findings suggest that the mutations impact the catalytic activity of ABH2 to a greater extent than its ability to associate with DNA strands. Collectively, these results show how changes to the active site affect molecular dynamics and reaction kinetics, improving our understanding of the substrate recognition process in this pivotal enzyme. Full article

Triple-negative breast cancer (TNBC) is a heterogenous group of breast tumors. This type of breast tumor is relatively difficult to manage, due to the lack of expression of Hormone Receptors (HR) and human epidermal growth factor receptor (HER2). Efforts have been made to understand the factors involved in determining how a triple-negative breast tumor responds to therapy. The standard of treatment in most cases today is a combined modality of immune checkpoint inhibitors (ICIs) and chemotherapy with agents such as anti-mitotic (taxanes) or DNA-damaging agents (alkylating agents, cyclophosphamides, platin salts). In this study, we investigated the predictive and prognostic factors for TNBC, in the neoadjuvant setting; understanding each patient’s response before treatment initiation is crucial to guiding the subsequent approach and finally improving patient outcomes. We focused on tumor-infiltrating lymphocytes at the site of the primary tumor (TILs), circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), the mutational status of protein 53 (p53), and Ki-67, investigating the potential roles of these factors in predicting responses to anti-cancer agents. Full article

Platinum resistance represents an urgent medical need in the management of ovarian cancer. The activity of the combinations of onvansertib, an inhibitor of polo-like kinase 1, with gemcitabine or carboplatin was tested using patient-derived xenografts of high-grade serous ovarian carcinoma resistant to cisplatin (DDP). Two PDX models were selected from our xenobank: one with acquired resistance to DDP (#266R) and the other (#315) with intrinsic DDP resistance. Tumor-bearing mice were randomized to receive vehicle, single onvansertib, gemcitabine and carboplatin, and their combinations. Onvansertib/gemcitabine and onvansertib/carboplatin combinations were well tolerated. In the #266R model, single drug treatments were completely inactive, while the combinations of onvansertib/gemcitabine and onvansertib/carboplatin resulted in a significant increase in survival compared to controls and single drugs (p < 0.001 versus control, onvansertib, gemcitabine and carboplatin). Similar efficacy was observed in the s.c. #315 PDX model; indeed, onvansertib and carboplatin monotherapies were inactive, gemcitabine monotherapy was marginally active, while both combinations were highly active. The molecular mechanism underlying the efficacy of the combinations suggests a higher induction of DNA damage which seems plausible considering that, in both cases, gemcitabine and carboplatin, respectively, interfere with DNA metabolism and induce alkylation damage. The results suggest that the combinations of onvansertib/gemcitabine and onvansertib/carboplatin are safe and were shown to be of therapeutic value in the platinum-resistant setting of ovarian carcinoma, strongly supporting their clinical translatability. Full article

Alkylating agents, historically employed as chemical warfare agents and currently used as chemotherapeutic drugs, are known to induce significant pulmonary toxicity. Current clinical interventions often fail to fully prevent or reverse these pathological changes, highlighting the urgent need for safe, broad-spectrum therapeutic agents that are effective across diverse exposure scenarios. Melatonin has emerged as a promising protective agent due to its antioxidant, anti-inflammatory, and immunomodulatory properties, along with a well-established safety profile. This systematic review evaluates the potential of melatonin in mitigating vesicant-induced pulmonary damage, synthesizing and critically analyzing preclinical evidence in accordance with the PRISMA guidelines. Three in vivo rodent studies met the inclusion criteria and were analyzed. In all cases, melatonin demonstrated protective effects against alkylating agents such as mechlorethamine (HN2) and cyclophosphamide (CP). These effects were dose-dependent and observed across various animal models, administration protocols, and dosages (ranging from 2.5 to 100 mg/kg), highlighting the importance of context-specific considerations. The human equivalent doses (HEDs) ranged from 12 to 973 mg per day, suggesting that the effective doses may exceed those typically used in clinical trials for other conditions. Melatonin’s pleiotropic mechanisms, including a reduction in oxidative stress, the modulation of inflammatory pathways, and support for tissue repair, reinforce its therapeutic potential in both prophylactic and treatment settings for alkylating agent exposure. Nonetheless, this review underscores the critical need for further randomized clinical trials to establish the optimal dosing strategies, refine treatment protocols, and fully elucidate melatonin’s role in managing alkylating-agent-induced pulmonary toxicity. Full article

Cancer medications can cause cardiac issues, which are difficult to treat in oncologic patients because of the risk of complications. In some cases, this may significantly impact their well-being and treatment outcomes. Overall, these complications fall under the term “drug induced cardiotoxicity”, mainly due to chemotherapy drugs being specifically toxic to the heart, causing a decrease in the heart’s capacity to pump blood efficiently and leading to a reduction in the left ventricular ejection fraction (LVEF), and subsequently possibly leading to heart failure. Anthracyclines, alkylating agents, and targeted therapies for cancer hold the potential of causing harmful effects on the heart. The incidence of heart-related issues varies from patient to patient and depends on multiple factors, including the type of medication, dosage, duration of the treatment, and pre-existing heart conditions. The underlying mechanism leading to oncologic-drug-induced cardiovascular harmful effects is quite complex. One particular group of drugs, called anthracyclines, have garnered attention due to their impact on oxidative stress and their ability to cause direct harm to heart muscle cells. Reactive oxygen species (ROS) cause harm by inducing damage and programmed cell death in heart cells. Conventional biomarkers alone can only indicate some degree of damage that has already occurred and, therefore, early detection is key. Novel methods like genetic profiling are being developed to detect individuals at risk, prior to the onset of clinical symptoms. Key management strategies—including early detection, personalized medicine approaches, and the use of novel biomarkers—play a crucial role in mitigating cardiotoxicity and improving patient outcomes. Identification of generated genetic alterations and the association to an increased likelihood of cardiotoxicity will allow treatment in a more personalized approach, aiming at decreasing rates of cardiac events while maintaining high oncological efficacy. Oncology drug-induced cardiotoxicity is managed through a combination of preventive strategies and therapeutic interventions from the union of cardiac and oncological knowledge. Full article

Background/Objectives: Effective anti-inflammatory treatment for COVID-19 is necessary. It was shown that ultra-low doses (100-fold lower than therapeutic ones) of alkylating drug melphalan (MEL) interact with cytokine cell receptors without DNA damage. A method of treating severe COVID-19 with ultra-low doses of MEL inhalations was proposed. The objective was to study the efficacy and safety of MEL inhalations for COVID-19 pneumonia treatment. Methods: An open-label comparative study (NCT04380376) with 120 patients divided into two groups was conducted. The control group (CG) received standard treatment, and the melphalan group (MG) also received seven daily 0.1 mg MEL inhalations. Changes in clinical improvement, inflammatory markers, and CT lung scan data were primary and secondary endpoints. Results: Patients in the MG showed significantly better clinical outcomes compared to the CG, with improvements in dyspnea according to the WHO Ordinal Scale of Clinical Improvement and the modified Borg Scale, CT scans, and inflammatory markers. No adverse effects (including irritant and bronchoconstrictor effects) possibly related to MEL were reported. Conclusions: This study demonstrated the efficacy of incorporating ultra-low-dose MEL inhalations into the therapeutic regimen for patients with COVID-19-associated pneumonia. This conclusion is supported by a statistically significant improvement in clinical outcomes, as assessed by the OSCI, a more rapid reduction in the severity of dyspnea, and a marked anti-inflammatory effect, evidenced by a faster decline in C-reactive protein levels. No adverse effects were observed with the proposed treatment method. Further large-scale randomized clinical trials are warranted to validate these findings and to evaluate the potential for the implementation of ultra-low-dose MEL inhalation in clinical practice. Full article

A wide variety of endogenous and exogenous alkylating agents covalently modify DNA to produce N7-alkyl-2′-deoxyguanosine (N7-alkylG) adducts as major DNA lesions. The mutagenic potentials of many N7-alkylG adducts with an intercalatable moiety remain poorly understood. We have discovered that the antiriot agent 2-chloroacetophenone readily reacts with dG to produce N7-acetophenone-dG adducts, implicating the genotoxic properties of 2-chloroacetophenone. 2-Chloroacetophenone, however, has been found to be nonmutagenic in both bacterial and mammalian cells. To gain insights into the nonmutagenic nature of N7-acetophenone-dG, we prepared N7-acetophenone-dG-containing oligonucleotide via 2′-fluorine-mediated transition-state destabilization and conducted kinetic and structural studies of human DNA polymerase eta (polη) incorporating nucleotide opposite 2′-F-N7-acetophenone-dG. The kinetic experiments reveal that the presence of the lesion at the templating position greatly hinders nucleotide incorporation. A crystal structure of polη bound to a nonhydrolyzable dCTP analog opposite 2′-F-N7-acetophenone-dG shows that the templating N7-acetophenone-dG is in a syn conformation, precluding binding of an incoming nucleotide in the catalytic site. These unusual conformations explain the observed inefficient incorporation of nucleotide opposite the lesion. Our studies suggest that certain bulky N7-alkylG lesions adopt a syn conformer and present an intercalatable moiety into the nascent base-pairing site, deterring nucleotide incorporation and thus lowering mutagenicity. Full article

Background/Objectives: In recent years the global incidence of cancer during pregnancy is rising, occurring in 1 out of every 1000 pregnancies. In this regard, the most used chemotherapy drugs to treat cancer are alkylating agents such as cyclophosphamide (Cp). Despite its great efficacy, has been associated with the production of oxidative stress and DNA damage, leading to embryotoxicity, genotoxicity, and teratogenicity in the developing conceptus. Therefore, this study aimed to investigate the protective role of phycobiliproteins (PBP) derived from Arthrospira maxima (spirulina) in reducing Cp-induced embryotoxicity and genotoxicity in pregnant CD1 mice. Methods: Pregnant CD1 mice were divided into five groups: control, Cp 20 mg/kg, and three doses of PBP (50, 100, and 200 mg/kg) + Cp co-treatment. PBP were administered orally from day 6 to 10.5 dpc, followed by a single intraperitoneal dose of Cp on 10.5 dpc. Embryos were collected at 12.5 dpc to assess morphological development and vascular alterations, while maternal DNA damage was evaluated using micronucleus assays and antioxidant enzyme activity in maternal plasma. Results: PBP exhibited a dose-dependent protective effect against Cp-induced damage. The 200 mg/kg PBP dose significantly reduced developmental abnormalities, micronucleated polychromatic erythrocytes, and oxidative stress, (as evidenced by increased SOD and GPx activity). Conclusions: Phycobiliproteins from Arthrospira maxima (spirulina) effectively reduced Cp-induced morphological and vascular alterations in embryos and genotoxicity in pregnant mice. These findings highlight their potential as a complementary therapy to mitigate teratogenic risks during chemotherapy. Further research is needed to optimize dosing and explore clinical applications. Full article

Cancer treatments have harmful side effects, including genotoxic ones. Our previous research discovered that a specific silver nanoparticle (AgNPs) formulation could reduce the genotoxic effects of an alkylating agent, cyclophosphamide. This study aims to evaluate if this protective effect is observed against an antimetabolite anticancer agent, cytosine arabinoside (Ara-C). An erythrocyte micronucleus assay was conducted on BALB/c mice. A most significant effect was observed after the application scheme, including three doses of Ara-C and three subsequent doses of AgNPs, resulting in a 3.7 and 2.0-fold decrease in the frequency of micronucleated reticulocytes and accumulated erythrocytes, respectively. Current and previous studies reveal that AgNPs could be used as a genoprotector against the genotoxic damage produced by the currently used antineoplastic antimetabolites and alkylating agents. It was revealed that AgNPs could be considered a new class of promising synthetic antineoplastic genoprotectants along with the known class of derivatives from natural sources. Full article

The plum fruit moth (PFM), Grapholita funebrana, and the oriental fruit moth (OFM), G. molesta, are closely related fruit moth species that severely damage fruit trees in Rosaceae. Both species share common primary sex pheromone components Z8-12:Ac and E8-12:Ac. The secondary sex pheromone components of PFMs consist of Z8-12:OH, Z8-14:Ac, and Z10-14:Ac, while those of OFMs include Z8-12:OH and 12:OH. Previous researchers have proved that the inclusion of Z8-14:Ac and Z10-14:Ac did not augment PFM catches but inhibited OFM catches in orchards in Europe, thereby maintaining the species-specificity of the PFM sex attractant. However, which of these components, Z8-14:Ac or Z10-14:Ac, plays the major role in inhibiting OFM attraction remains unclear. In the current study, electroantennogram (EAG) assays indicated that both OFM and PFM males exhibited a moderate EAG response to Z8-14:Ac and Z10-14:Ac. Rubber septa loaded with varying ratios of Z8-14:Ac (1% to 30%) or Z10-14:Ac (5% to 110%) combined with a constant dose of Z8-12:Ac and E8-12:Ac produced diverse trapping effects. Sex attractants containing Z8-14:Ac did not significantly affect the trapping of PFM males but drastically reduced the capture of OFM males, with the reduction reaching up to 96.54%. Attractants containing more than 10% of Z10-14:Ac simultaneously reduced the number of OFM and PFM males captured. Z8-14:Ac was indispensable for maintaining the specificity of sex pheromones. Fluorescence competitive binding assays of recombinant GmolPBP2 showed the lowest K_i value (0.66 ± 0.02 μM) among the PBPs/GOBPs from OFMs, suggesting that it is the most likely target for Z8-14:Ac. Molecular dynamic simulation and site-directed mutagenesis assays confirmed that the Phe12 residue, which forms a π–alkyl interaction with Z8-14:Ac, was crucial for GmolPBP2 binding to Z8-14:Ac. In conclusion, Z8-14:Ac is vital to the specificity of PFM sex pheromones inhibiting OFM attractants when added to Z8-12:Ac and E8-12:Ac. This could be potentially used to develop species-specific sex attractants for the PFM. Full article