Cisplatin-induced hydroxyl radicals mediate pro-survival autophagy in human lung cancer H460 cells

Radical-triggered ring-opening of aminocyclopropane for detection of hydroxyl radicals in living cells

Hydroxyl radicals (˙OH), highly reactive oxygen species involved in oxidative stress and cancer therapy, are challenging to detect intracellularly due to their short lifetime, low concentration, and high reactivity. To address this, a novel ˙OH-specific fluorescent probe, CC-7, was developed by integrating an aminocyclopropane group into a coumarin derivative. This design was inspired by the radical-mediated ring-opening of aminocyclopropanes in synthetic chemistry. The ring-opening reaction triggered by ˙OH in CC-7 produces a significant "Fluorescence-ON" response with a 10-fold increase in intensity, demonstrating high selectivity for ˙OH over other reactive oxygen species. CC-7 effectively visualized intracellular ˙OH, distinguished between normal (HEK-293T) and cancer cells (4T1), and monitored ˙OH generated by chemotherapeutic agents like doxorubicin and cisplatin. This study highlights CC-7 as a powerful tool for selectively detecting ˙OH in living cells, with potential applications in investigating oxidative stress-related diseases and monitoring cancer therapy.

Autophagy-driven regulation of cisplatin response in human cancers: Exploring molecular and cell death dynamics

Despite the challenges posed by drug resistance and side effects, chemotherapy remains a pivotal strategy in cancer treatment. A key issue in this context is macroautophagy (commonly known as autophagy), a dysregulated cell death mechanism often observed during chemotherapy. Autophagy plays a cytoprotective role by maintaining cellular homeostasis and recycling organelles, and emerging evidence points to its significant role in promoting cancer progression. Cisplatin, a DNA-intercalating agent known for inducing cell death and cell cycle arrest, often encounters resistance in chemotherapy treatments. Recent studies have shown that autophagy can contribute to cisplatin resistance or insensitivity in tumor cells through various mechanisms. This resistance can be mediated by protective autophagy, which suppresses apoptosis. Additionally, autophagy-related changes in tumor cell metastasis, particularly the induction of Epithelial-Mesenchymal Transition (EMT), can also lead to cisplatin resistance. Nevertheless, pharmacological strategies targeting the regulation of autophagy and apoptosis offer promising avenues to enhance cisplatin sensitivity in cancer therapy. Notably, numerous non-coding RNAs have been identified as regulators of autophagy in the context of cisplatin chemotherapy. Thus, therapeutic targeting of autophagy or its associated pathways holds potential for restoring cisplatin sensitivity, highlighting an important direction for future clinical research.

Class III plant peroxidases: From classification to physiological functions

Peroxidases (EC 1.11.1.7) are involved in a wide range of physiological processes, hence their broad distribution across biological systems. These proteins can be classified as haem or non-haem enzymes. According to the RedOxiBase database, haem peroxidases are approximately 84 % of all known peroxidase enzymes. Class III plant peroxidases are haem-enzymes that share similar three-dimensional structures and a common catalytic mechanism for hydrogen peroxide degradation. They exist as large multigene families and are involved in metabolizing Reactive Oxygen Species (ROS), hormone synthesis and decomposition, fruit growth, defense, and cell wall synthesis and maintenance. As a result, plant peroxidases gained attention in research and became one of the most extensively studied groups of enzymes. This review provides an update on the database, classification, phylogeny, mechanism of action, structure, and physiological functions of class III plant peroxidases.

Does each Component of Reactive Oxygen Species have a Dual Role in the Tumor Microenvironment?

Reactive oxygen species (ROS) are a class of highly reactive oxidizing molecules, including superoxide anion (O2 •-) and hydrogen peroxide (H2O2), among others. Moderate levels of ROS play a crucial role in regulating cellular signaling and maintaining cellular functions. However, abnormal ROS levels or persistent oxidative stress can lead to changes in the tumor microenvironment (TME) that favor cancer development. This review provides an overview of ROS generation, structure, and properties, as well as their effects on various components of the TME. Contrary to previous studies, our findings reveal a dual effect of ROS on different components of the TME, whereby ROS can either enhance or inhibit certain factors, ultimately leading to the promotion or suppression of the TME. For example, H2O2 has dual effects on immune cells and non-- cellular components within the TME, while O2 •- has dual effects on T cells and fibroblasts. Furthermore, each component demonstrates distinct mechanisms of action and ranges of influence. In the final section of the article, we summarize the current clinical applications of ROS in cancer treatment and identify certain limitations associated with existing therapeutic approaches. Therefore, this review aims to provide a comprehensive understanding of ROS, highlighting their dual effects on different components of the TME, and exploring the potential clinical applications that may pave the way for future treatment and prevention strategies.

Potent Ruthenium-Ferrocene Bimetallic Antitumor Antiangiogenic Agent That Circumvents Platinum Resistance: From Synthesis and Mechanistic Studies to In Vivo Evaluation in Zebrafish

Emergence of resistance in cancer cells and dose-limiting side effects severely limit the widespread use of platinum (Pt) anticancer drugs. Multi-action hybrid anticancer agents that are constructed by merging two or more pharmacophores offer the prospect of circumventing issues of Pt drugs. Herein, we report the design, synthesis, and in-depth biological evaluation of a ruthenium-ferrocene (Ru-Fc) bimetallic agent [(η6-p-cymene)Ru(1,1,1-trifluoro-4-oxo-4-ferrocenyl-but-2-en-2-olate)Cl] and its five analogues. Along with aquation/anation chemistry, we evaluated the in vitro antitumor potency, Pt cross-resistance profile, and in vivo antiangiogenic properties. A structure activity analysis was performed to understand the impact of Fc, CF3, and p-cymene groups on the anticancer potency of the Ru-Fc hybrid. Finally, in addition to assessing cellular uptake and intracellular distribution, we demonstrated that the Ru-Fc hybrid binds to nucleophilic biomolecules and produces reactive oxygen species, which causes mitochondrial dysfunction and induces ER stress, leading to poly(ADP-ribose) polymerase-mediated necroptotic cell death.

Long non-coding RNA (lncRNA) H19 in human cancer: From proliferation and metastasis to therapy

Initiation and development of cancer depend on multiple factors that mutations in genes and epigenetic level can be considered as important drivers. Epigenetic factors include a large family of members and understanding their function in cancer has been a hot topic. LncRNAs are RNA molecules with no capacity in synthesis of proteins, and they have regulatory functions in cells. LncRNAs are localized in nucleus and cytoplasm, and their abnormal expression is related to development of tumor. This manuscript emphasizes on the role of lncRNA H19 in various cancers and its association with tumor hallmarks. The function of lncRNA H19 in most tumors is oncogenic and therefore, tumor cells increase its expression for promoting their progression. LncRNA H19 contributes to enhancing growth and cell cycle of cancers and by EMT induction, it is able to elevate metastasis rate. Silencing H19 induces apoptotic cell death and disrupts progression of tumors. LncRNA H19 triggers chemo- and radio-resistance in cancer cells. miRNAs are dually upregulated/down-regulated by lncRNA H19 in increasing tumor progression. Anti-cancer agents reduce lncRNA H19 in impairing tumor progression and increasing therapy sensitivity. A number of downstream targets and molecular pathways for lncRNA H19 have been detected in cancers including miRNAs, RUNX1, STAT3, β-catenin, Akt2 and FOXM1. Clinical studies have revealed potential of lncRNA H19 as biomarker and its association with poor prognosis. LncRNA H19 can be transferred to cancer cells via exosomes in enhancing their progression.

Upregulation of nuclear division cycle 80 contributes to therapeutic resistance via the promotion of autophagy-related protein-7-dependent autophagy in lung cancer

Lung cancer remains the leading cause of malignant mortality worldwide. Hence, the discovery of novel targets that can improve therapeutic effects in lung cancer patients is an urgent need. In this study, we screened differentially expressed genes using isobaric tags for relative and absolute quantitation (iTRAQ) analysis and datasets from the cancer genome atlas database, and found that nuclear division cycle 80 (NDC80) might act as a novel prognostic indicator of lung cancer. The expression of NDC80 was significantly increased in lung cancer tissues, as compared to normal tissues, and high expression levels of NDC80 were correlated with unfavorable survival rates. Furthermore, an in vitro analysis showed that the stable knockdown of NDC80 decreased the cell viability and increased therapeutic sensitivity in two lung cancer cell lines, A549-IRR and H1246-IRR. Moreover, gene set enrichment analysis results showed that NDC80 was enriched in autophagy-related pathways. The downregulation of NDC80 inhibited the formation of autophagosomes, and reduced the expression of autophagy-related proteins such as LC3II, Beclin-1, and p62 in lung cancer cells. To further clarify the role of NDC80 as a downstream regulator of autophagy, we validated autophagic mediators through iTRAQ analysis and real-time polymerase chain reaction arrays. Autophagy-related protein7 (ATG7) was observed to be downregulated after the knockdown of NDC80 in lung cancer cells. Immunohistochemistry assay results revealed that both NDC80 and ATG7 were upregulated in an array of lung adenocarcinoma samples, compared to normal tissues, and the expression of NDC80 was identified to be positively associated with the levels of ATG7. Our findings suggest that NDC80 promotes the development of lung cancer by regulating autophagy, and might serve as a potential target for increasing the therapeutic sensitivity of lung cancer.

Programmed Catalytic Therapy-Mediated ROS Generation and T-Cell Infiltration in Lung Metastasis by a Dual Metal-Organic Framework (MOF) Nanoagent

Nano-catalytic agents actuating Fenton-like reaction in cancer cells cause intratumoral generation of reactive oxygen species (ROS), allowing the potential for immune therapy of tumor metastasis via the recognition of tumor-associated antigens. However, the self-defense mechanism of cancer cells, known as autophagy, and unsustained ROS generation often restricts efficiency, lowering the immune attack, especially in invading metastatic clusters. Here, a functional core-shell metal-organic framework nanocube (dual MOF) doubling as a catalytic agent and T cell infiltration inducer that programs ROS and inhibits autophagy is reported. The dual MOF integrated a Prussian blue (PB)-coated iron (Fe²⁺)-containing metal-organic framework (MOF, MIL88) as a programmed peroxide mimic in the cancer cells, facilitating the sustained ROS generation. With the assistance of Chloroquine (CQ), the inhibition of autophagy through lysosomal deacidification breaks off the self-defense mechanism and further improves the cytotoxicity. The purpose of this material design was to inhibit autophagy and ROS efficacy of the tumor, and eventually improve T cell recruitment for immune therapy of lung metastasis. The margination and internalization-mediated cancer cell uptake improve the accumulation of dual MOF of metastatic tumors in vivo. The effective catalytic dual MOF integrated dysfunctional autophagy at the metastasis elicits the ~3-fold recruitment of T lymphocytes. Such synergy of T cell recruitment and ROS generation transported by dual MOF during the metastases successfully suppresses more than 90% of tumor foci in the lung.

Platinum-Induced Peripheral Neuropathy (PIPN): ROS-Related Mechanism, Therapeutic Agents, and Nanosystems

Platinum (Pt) drugs (e.g., oxaliplatin, cisplatin) are applied in the clinic worldwide for the treatment of various cancers. However, platinum-induced peripheral neuropathy (PIPN) caused by the accumulation of Pt in the peripheral nervous system limits the clinical application, whose prevention and treatment are still a huge challenge. To date, Pt-induced reactive oxygen species (ROS) generation has been studied as one of the primary mechanisms of PIPN, whose downregulation would be feasible to relieve PIPN. This review will discuss ROS-related PIPN mechanisms including Pt accumulation in the dorsal root ganglia (DRG), ROS generation, and cellular regulation. Based on them, some antioxidant therapeutic drugs will be summarized in detail to alleviate the Pt-induced ROS overproduction. More importantly, we focus on the cutting-edge nanotechnology in view of ROS-related PIPN mechanisms and will discuss the rational fabrication of tailor-made nanosystems for efficiently preventing and treating PIPN. Last, the future prospects and potential breakthroughs of these anti-ROS agents and nanosystems will be briefly discussed.