Mechanisms linked to differences in the mutagenic potential of 1,3-dinitropyrene and 1,8-dinitropyrene

A nanocomposite competent to overcome cascade drug resistance in ovarian cancer via mitochondria dysfunction and NO gas synergistic therapy

Ovarian cancer (OC) is one of the most common and recurring malignancies in gynecology. Patients with relapsed OC always develop "cascade drug resistance" (CDR) under repeated chemotherapy, leading to subsequent failure of chemotherapy. To overcome this challenge, amphiphiles (P1) carrying a nitric oxide (NO) donor (Isosorbide 5-mononitrate, ISMN) and high-density disulfide are synthesized for encapsulating mitochondria-targeted tetravalent platinum prodrug (TPt) to construct a nanocomposite (INP@TPt). Mechanism studies indicated that INP@TPt significantly inhibited drug-resistant cells by increasing cellular uptake and mitochondrial accumulation of platinum, depleting glutathione, and preventing apoptosis escape through generating highly toxic peroxynitrite anion (ONOO-). To better replicate the microenvironmental and histological characteristics of the drug resistant primary tumor, an OC patient-derived tumor xenograft (PDXOC) model in BALB/c nude mice was established. INP@TPt showed the best therapeutic effects in the PDXOC model. The corresponding tumor tissues contained high ONOO- levels, which were attributed to the simultaneous release of O2•- and NO in tumor tissues. Taken together, INP@TPt-based systematic strategy showed considerable potential and satisfactory biocompatibility in overcoming platinum CDR, providing practical applications for ovarian therapy.

A Systematic Review of Polycyclic Aromatic Hydrocarbon Derivatives: Occurrences, Levels, Biotransformation, Exposure Biomarkers, and Toxicity

Polycyclic aromatic hydrocarbon (PAH) derivatives constitute a significant class of emerging contaminants that have been ubiquitously detected in diverse environmental matrixes, with some even exhibiting higher toxicities than their corresponding parent PAHs. To date, compared with parent PAHs, fewer systematic summaries and reanalyses are available for PAH derivatives with great environmental concerns. This review summarizes the current knowledge on the chemical species, levels, biotransformation patterns, chemical analytical methods, internal exposure routes with representative biomarkers, and toxicity of PAH derivatives, primarily focusing on nitrated PAHs (NPAHs), oxygenated PAHs (OPAHs), halogenated PAHs (XPAHs), and alkylated PAHs (APAHs). A collection of 188 compounds from four categories, 44 NPAHs, 36 OPAHs, 56 APAHs, and 52 XPAHs, has been compiled from 114 studies that documented the environmental presence of PAH derivatives. These compounds exhibited weighted average air concentrations that varied from a lower limit of 0.019 pg/m3 to a higher threshold of 4060 pg/m3. Different analytical methods utilizing comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry (GC × GC-TOF-MS), gas chromatography coupled to time-of-flight mass spectrometry (GC-TOF-MS), comprehensive two-dimensional gas chromatography coupled to quadrupole mass spectrometry (GC × GC-QQQ-MS), and Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS), that adopted untargeted strategies for the identification of PAH derivatives are also reviewed here. Additionally, an in-depth analysis of biotransformation patterns for each category is provided, including the likelihood of specific biotransformation reaction types. For the toxicity, we primarily summarized key metabolic activation pathways, which could result in the formation of reactive metabolites capable of covalently bonding with DNA and tissue proteins, and potential health outcomes such as carcinogenicity and genotoxicity, oxidative stress, inflammation and immunotoxicity, and developmental toxicity that might be mediated by the aryl hydrocarbon receptor (AhR). Finally, we pinpoint research challenges and emphasize the need for further studies on identifying PAH derivatives, tracking external exposure levels, evaluating internal exposure levels and associated toxicity, clarifying exposure routes, and considering mixture exposure effects. This review aims to provide a broad understanding of PAH derivatives' identification, environmental occurrence, human exposure, biotransformation, and toxicity, offering a valuable reference for guiding future research in this underexplored area.

Synergetic delivery of artesunate and isosorbide 5-mononitrate with reduction-sensitive polymer nanoparticles for ovarian cancer chemotherapy

Ovarian cancer is a highly fatal gynecologic malignancy worldwide. Chemotherapy remains the primary modality both for primary and maintenance treatments of ovarian cancer. However, the progress in developing chemotherapeutic agents for ovarian cancer has been slow in the past 20 years. Thus, new and effective chemotherapeutic drugs are urgently needed for ovarian cancer treatment. A reduction-responsive synergetic delivery strategy (PSSP@ART-ISMN) with co-delivery of artesunate and isosorbide 5-mononitrate was investigated in this research study. PSSP@ART-ISMN had various effects on tumor cells, such as (i) inducing the production of reactive oxygen species (ROS), which contributes to mitochondrial damage; (ii) providing nitric oxide and ROS for the tumor cells, which further react to generate highly toxic reactive nitrogen species (RNS) and cause DNA damage; and (iii) arresting cell cycle at the G0/G1 phase and inducing apoptosis. PSSP@ART-ISMN also demonstrated excellent antitumor activity with good biocompatibility in vivo. Taken together, the results of this work provide a potential delivery strategy for chemotherapy in ovarian cancer.

IRE-1-Targeting Caged Prodrug with Endoplasmic Reticulum Stress-Inducing and XBP-1S-Inhibiting Activities for Cancer Therapy

Activation of the IRE-1/XBP-1s pathway supports tumor progression. Here, we report a novel prodrug, TC-D-F07, in which a thiol-reactive dinitrobenzenesulfonyl (Dns) cage was installed onto the C8 hydroxyl of the covalent IRE-1 inhibitor D-F07. The electron-withdrawing Dns group in TC-D-F07 stabilizes the neighboring 1,3-dioxane acetal, allowing for stimulus-mediated control of its inhibitory activity. TC-D-F07 exhibits high sensitivity to intracellular thiols. Because tumor cells exhibit higher concentrations of glutathione and cysteine, treatment with TC-D-F07 results in more sustained levels of D-F07 in transformed versus normal cells. In addition, we show that a dinitrophenyl cysteine adduct resulting from cleavage of the Dns group induces endoplasmic reticulum (ER) stress, causing tumor cells to increase the expression of XBP-1s. The accumulated levels of D-F07 and its gradual decomposition into the active IRE-1 inhibitor eventually deprive tumor cells of XBP-1s, leading to more severe apoptosis than those treated with its uncaged analogue.