Mitoxantrone. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in the chemotherapy of cancer

Targeted delivery strategy of indocyanine green-mitoxantrone loaded liposomes co-modified with BTP-7 and BR2 for the treatment of glioma

OBJECTIVE

This study aims to develop a dual-ligand-modified targeted drug delivery system by integrating photosensitizers and chemotherapeutic drugs to enhance anti-glioma effects. The system is designed to overcome the blood-brain barrier (BBB) that hinders effective drug delivery, increase drug accumulation in glioma cells, and thereby enhance therapeutic efficacy.

METHODS

Liposomes were prepared using the film dispersion-ammonium sulfate gradient technique, co-loading the photosensitizer indocyanine green (ICG) and the chemotherapeutic drug mitoxantrone (MTO). The conjugation of BTP-7 and BR2 to the liposome surface was achieved using an organic phase reaction method. The stability, dispersibility, particle size, and potential of the modified liposomes were tested. Their ability to penetrate the BBB and accumulate in glioma was evaluated in BBB models and cellular uptake studies. Additionally, the anti-tumor activity of this combination approach was assessed.

RESULTS

The resulting liposomes demonstrated significant stability and dispersibility, with an average particle size of 142.3 ± 1.8 nm and a potential of -17.6 mV. BBB model and cellular uptake studies indicated that BTP-7/BR2-ICG/MTO-LP could not only penetrate the BBB but also accumulate in glioma, leading to glioma cell necrosis. The anti-tumor activity evaluation showed that this combination approach exhibited a strong tumor-suppressing effect.

CONCLUSION

The dual-ligand-modified liposomes developed in this study can penetrate the blood-brain barrier and achieve targeted drug delivery in glioma therapy. The combination of BTP-7 and BR2 not only enhances the carrier's penetration ability but also increases intracellular drug accumulation, thereby improving therapeutic efficacy. This novel therapeutic approach, which combines chemotherapy and photothermal response via dual-ligand-modified liposomes delivered to the tumor site, demonstrates the potential to reduce drug-related side effects and improve treatment outcomes.

A comprehensive review of oncogenic Notch signaling in multiple myeloma

Multiple myeloma remains an incurable plasma cell cancer with radical case-by-case heterogeneity. Because of this, personalized and disease-specific biology of multiple myeloma must be understood for the discovery of effective molecular targets. The highly evolutionarily conserved Notch signaling pathway has been extensively described as a multifaceted driver of the multiple myeloma disease process-contributing to both intrinsic effects of malignant cells and to widespread remodeling of the tumor microenvironment that further facilitates disease progression. Namely, Notch signaling amongst malignant cells promotes increased proliferation, tumor-initiating capacity, drug resistance, and invasiveness. Moreover, Notch signaling between malignant cells and cells of the tumor microenvironment leads to increased osteodegenerative disease and angiogenesis. This comprehensive review will discuss both the intrinsic implications of pathological Notch signaling in multiple myeloma and the extrinsic implications of Notch signaling in the multiple myeloma tumor microenvironment. Additionally, the genetic origins of Notch signaling dysregulation in multiple myeloma and current attempts at targeting Notch therapeutically will be reviewed. While the subject has been reviewed previously, recent developments in the intervening years demand a revised synthesis of the literature. The aim of this work is to introduce and thoroughly synthesize the current state of knowledge in this vein of research and to highlight future directions for both new and in-the-field scientists.

Development of Mitoxantrone-Loaded Quercetin Nanoparticles for Breast Cancer Therapy with Potential for Synergism with Bioactive Natural Products

Nanoparticle (NP)-based drug delivery systems have caused a paradigm shift in cancer treatment by enabling drug targeting, sustaining drug release, and reducing systemic toxicity of chemotherapy. Here we developed a novel NP formulation for the anticancer drug mitoxantrone (MTZ) by loading it into an emerging nanomaterial derived from the plant polyphenol quercetin (QCT). QCT was partially oxidized to produce amphiphilic oxQCT which was co-assembled with poly(ethylene glycol) (PEG) and MTZ by nanoprecipitation to form MTZ NPs. The optimal NPs exhibited an average diameter of 128 nm, a polydispersity index of 0.22, and a drug loading efficiency of 76%. While only a small fraction of the loaded drug was released at physiologic pH, a significantly higher fraction was released at acidic pH. The anticancer activity of MTZ NPs was assessed in MCF-7 and MDA-MB-231 breast cancer cell lines, alone and in combination with the bioactive natural products curcumin (CUR) and thymoquinone (TQ). In cell viability assays, MTZ NPs were slightly less potent than free MTZ, most likely due to their sustained release properties, but their cytotoxicity was greatly enhanced in the presence of TQ (in MCF-7 cells) as well as CUR (in MDA-MB-231 cells). The results were corroborated by apoptosis assays such as mitochondrial membrane potential measurement, acridine orange/ethidium bromide staining, in addition to caspase activity assays. The assays revealed that the NPs' proapoptotic effect was enhanced in the presence of CUR or TQ, depending on the cell line. Our work presents a promising nanocarrier platform for MTZ with the potential to enhance its bioactivity against breast cancer when combined with bioactive natural products.

Drug-induced self-assembled nanovesicles for chloroquine to sensitize MDR tumors to mitoxantrone hydrochloride

Multidrug resistance (MDR) is an incidental trouble post-chemotherapy, necessitating innovative therapeutic strategies. This study explores the potential of chloroquine (CQ) as a sensitizer for mitoxantrone hydrochloride (MitH) in drug-resistant tumors and introduces a novel pH-responsive drug-induced self-assembly nanovesicle (DIV) based on an amphiphilic polyphosphonitrile (PPAP) for the co-delivery of MitH and CQ. PPAP cannot self-assemble into nanovesicles alone, but when a certain amount of MitH was added, the multiple non-covalent interactions between PPAP and MitH contributed to the formation of DIV, which exactly improved the co-loading content of MitH and CQ to a large extent. CQ prevents MitH efflux and autophagy to reverse MitH resistance. Given the synergy between MitH and CQ at a 1:2 mass ratio with a combination index of 0.40 in K562/ADR cells, MitH and CQ co-loaded DIV (MC-DIV) is constructed and demonstrates a sensitivity index of 7.1 on cytotoxicity compared to free MitH. Furthermore, MC-DIV achieves extended circulation time, synchronous dual-drug delivery, and improved tumor targeting following systemic administration, resulting in exceptional antitumor efficacy in K562/ADR xenograft models with a tumor inhibition rate of 83.0 %. Overall, MC-DIV provides a viable method to maximize the loading capacity of nanocarriers, and potentially serves as a promising formulation for various MitH-resistant tumors.

Unveiling the multifaceted interactions of antitumor drug mitoxantrone with ct-DNA through biophysical and in silico studies

Mitoxantrone, an anthraquinone derivative, is a widely used anticancer drug with its well-known ability to engage in complex interactions with DNA. Although known for its intercalating ability, the enigma surrounding its binding modes with DNA persists. The existing corpus of literature primarily focuses on mitoxantrone-DNA interactions with short DNA sequences, thereby yielding insights into its interactive nature is limited to this specific sequence. This study aims to elucidate the diverse modes with which mitoxantrone interacts with calf thymus DNA using a combination of spectroscopy, calorimetry and in silico studies. The findings from spectroscopic, calorimetric and molecular dynamic results in correlation with existing literature, unveil a fascinating narrative: mitoxantrone intercalates at lower concentrations but promotes condensation at higher concentrations. Although intercalation with side chains positioned in the minor/major groove is the major binding mode in GC-rich sequences, molecular modelling studies hint at an alternative binding mode in AT-rich sequences where it exclusively displays pure electrostatic interaction. These findings underscore the pivotal role of both drug structure and base sequence in dictating binding mode and affinity. Such insights not only deepen the understanding of structure-activity relationships but also hold promise for guiding future drug design strategies.

m6A-modified cenRNA stabilizes CENPA to ensure centromere integrity in cancer cells

m6A modification is best known for its critical role in controlling multiple post-transcriptional processes of the mRNAs. Here, we discovered elevated levels of m6A modification on centromeric RNA (cenRNA) in cancerous cells compared with non-cancerous cells. We then identified CENPA, an H3 variant, as an m6A reader of cenRNA. CENPA is localized at centromeres and is essential in preserving centromere integrity and function during mitosis. The m6A-modified cenRNA stabilizes centromeric localization of CENPA in cancer cells during the S phase of the cell cycle. Mutations of CENPA at the Leu61 and the Arg63 or removal of cenRNA m6A modification lead to loss of centromere-bound CENPA during S phase. This in turn results in compromised centromere integrity and abnormal chromosome separation and hinders cancer cell proliferation and tumor growth. Our findings unveil an m6A reading mechanism by CENPA that epigenetically governs centromere integrity in cancer cells, providing potential targets for cancer therapy.

Mitoxantrone ameliorates ineffective erythropoiesis in a β-thalassemia intermedia mouse model

ABSTRACT

β-thalassemia is a condition characterized by reduced or absent synthesis of β-globin resulting from genetic mutations, leading to expanded and ineffective erythropoiesis. Mitoxantrone has been widely used clinically as an antitumor agent considering its ability to inhibit cell proliferation. However, its therapeutic effect on expanded and ineffective erythropoiesis in β-thalassemia is untested. We found that mitoxantrone decreased α-globin precipitates and ameliorated anemia, splenomegaly, and ineffective erythropoiesis in the HbbTh3/+ mouse model of β-thalassemia intermedia. The partially reversed ineffective erythropoiesis is a consequence of effects on autophagy as mitochondrial retention and protein levels of mTOR, P62, and LC3 in reticulocytes decreased in mitoxantrone-treated HbbTh3/+ mice. These data provide significant preclinical evidence for targeting autophagy as a novel therapeutic approach for β-thalassemia.

Laser-activable murine ferritin nanocage for chemo-photothermal therapy of colorectal cancer

Chemotherapy, as a conventional strategy for tumor therapy, often leads to unsatisfied therapeutic effect due to the multi-drug resistance and the serious side effects. Herein, we genetically engineered a thermal-responsive murine Ferritin (mHFn) to specifically deliver mitoxantrone (MTO, a chemotherapeutic and photothermal agent) to tumor tissue for the chemotherapy and photothermal combined therapy of colorectal cancer, thanks to the high affinity of mHFn to transferrin receptor that highly expressed on tumor cells. The thermal-sensitive channels on mHFn allowed the effective encapsulation of MTO in vitro and the laser-controlled release of MTO in vivo. Upon irradiation with a 660 nm laser, the raised temperature triggered the opening of the thermal-sensitive channel in mHFn nanocage, resulting in the controlled and rapid release of MTO. Consequently, a significant amount of reactive oxygen species was generated, causing mitochondrial collapse and tumor cell death. The photothermal-sensitive controlled release, low systemic cytotoxicity, and excellent synergistic tumor eradication ability in vivo made mHFn@MTO a promising candidate for chemo-photothermal combination therapy against colorectal cancer.

Historical Perspective and Current Trends in Anticancer Drug Development

Cancer is considered one of the leading causes of death in the 21st century. The intensive search for new anticancer drugs has been actively pursued by chemists and pharmacologists for decades, focusing either on the isolation of compounds with cytotoxic properties from plants or on screening thousands of synthetic molecules. Compounds that could potentially become candidates for new anticancer drugs must have the ability to inhibit proliferation and/or induce apoptosis in cancer cells without causing too much damage to normal cells. Some anticancer compounds were discovered by accident, others as a result of long-term research. In this review, we have presented a brief history of the development of the most important groups of anticancer drugs, pointing to the fact that they all have many side effects.

Phytotherapeutics in Cancer: From Potential Drug Candidates to Clinical Translation

Annually, a significant number of individuals succumb to cancer, an anomalous cellular condition characterized by uncontrolled cellular proliferation and the emergence of highly perilous tumors. Identifying underlying molecular mechanism(s) driving disease progression has led to various inventive therapeutic approaches, many of which are presently under pre-clinical and/or clinical trials. Over the recent years, numerous alternative strategies for addressing cancer have also been proposed and put into practice. This article delineates the modern therapeutic drugs employed in cancer treatment and their associated toxicity. Due to inherent drug toxicity associated with most modern treatments, demand rises for alternative therapies and phytochemicals with minimal side effects and proven efficacy against cancer. Analogs of taxol, Vinca alkaloids like vincristine and vinblastine, and podophyllotoxin represent a few illustrative examples in this context. The phytochemicals often work by modifying the activity of molecular pathways that are thought to be involved in the onset and progression of cancer. The principal objective of this study is to provide an overview of our current understanding regarding the pharmacologic effects and molecular targets of the active compounds found in natural products for cancer treatment and collate information about the recent advancements in this realm. The authors' interest in advancing the field of phytochemical research stems from both the potential of these compounds for use as drugs as well as their scientific validity. Accordingly, the significance of herbal formulations is underscored, shedding light on anticancer phytochemicals that are sought after at both pre-clinical and clinical levels, with discussion on the opportunities and challenges in pre-clinical and clinical cancer studies.

Design, synthesis, and evaluation of a mitoxantrone probe (MXP) for biological studies

Mitoxantrone (MX) is a robust chemotherapeutic with well-characterized applications in treating certain leukemias and advanced breast and prostate cancers. The canonical mechanism of action associated with MX is its ability to intercalate DNA and inhibit topoisomerase II, giving it the designation of a topoisomerase II poison. Years after FDA approval, investigations have unveiled novel protein-binding partners, such as methyl-CpG-binding domain protein (MBD2), PIM1 serine/threonine kinase, RAD52, and others that may contribute to the therapeutic profile of MX. Moreover, recent proteomic studies have revealed MX's ability to modulate protein expression, illuminating the complex cellular interactions of MX. Although mechanistically relevant, the differential expression across the proteome does not address the direct interaction with potential binding partners. Identification and characterization of these MX-binding cellular partners will provide the molecular basis for the alternate mechanisms that influence MX's cytotoxicity. Here, we describe the design and synthesis of a MX-biotin probe (MXP) and negative control (MXP-NC) that can be used to define MX's cellular targets and expand our understanding of the proteome-wide profile for MX. In proof of concept studies, we used MXP to successfully isolate a recently identified protein-binding partner of MX, RAD52, in a cell lysate pulldown with streptavidin beads and western blotting.

Molecular and neuroimmune pharmacology of S1P receptor modulators and other disease-modifying therapies for multiple sclerosis

Multiple sclerosis (MS) is a neurological, immune-mediated demyelinating disease that affects people in the prime of life. Environmental, infectious, and genetic factors have been implicated in its etiology, although a definitive cause has yet to be determined. Nevertheless, multiple disease-modifying therapies (DMTs: including interferons, glatiramer acetate, fumarates, cladribine, teriflunomide, fingolimod, siponimod, ozanimod, ponesimod, and monoclonal antibodies targeting ITGA4, CD20, and CD52) have been developed and approved for the treatment of MS. All the DMTs approved to date target immunomodulation as their mechanism of action (MOA); however, the direct effects of some DMTs on the central nervous system (CNS), particularly sphingosine 1-phosphate (S1P) receptor (S1PR) modulators, implicate a parallel MOA that may also reduce neurodegenerative sequelae. This review summarizes the currently approved DMTs for the treatment of MS and provides details and recent advances in the molecular pharmacology, immunopharmacology, and neuropharmacology of S1PR modulators, with a special focus on the CNS-oriented, astrocyte-centric MOA of fingolimod.

Design, synthesis, and evaluation of a mitoxantrone probe (MXP) for biological studies

Mitoxantrone (MX) is a robust chemotherapeutic with well-characterized applications in treating certain leukemias and advanced breast and prostate cancers. The canonical mechanism of action associated with MX is its ability to intercalate DNA and inhibit topoisomerase II, giving it the designation of a topoisomerase II poison. Years after FDA approval, investigations have unveiled novel protein-binding partners, such as methyl-CpG-binding domain protein (MBD2), PIM1 serine/threonine kinase, RAD52, and others that may contribute to the therapeutic profile of MX. Moreover, recent proteomic studies have revealed MX's ability to modulate protein expression, illuminating the complex cellular interactions of MX. Although mechanistically relevant, the differential expression across the proteome does not address the direct interaction with potential binding partners. Identification and characterization of these MX-binding cellular partners will provide the molecular basis for the alternate mechanisms that influence MX's cytotoxicity. Here, we describe the design and synthesis of a MX-biotin probe (MXP) and negative control (MXP-NC) that can be used to define MX's cellular targets and expand our understanding of the proteome-wide profile for MX. In proof of concept studies, we used MXP to successfully isolate a recently identified protein-binding partner of MX, RAD52, in a cell lysate pulldown with streptavidin beads and western blotting.

Graphical abstract Draft

Highlights

An 8-step synthesis was used to generate a biotinylated-mitoxantrone probe (MXP).A pulldown of MXP demonstrated selectivity for RAD52, but not Replication Protein A.Western blot confirmed the identity of the isolated protein, RAD52.

Genome-Wide DNA Methylation and Gene Expression Profiling Characterizes Molecular Subtypes of Esophagus Squamous Cell Carcinoma for Predicting Patient Survival and Immunotherapy Efficacy

Simple Summary

Esophageal squamous cell carcinoma (ESCC) represents roughly 85–90% of all esophageal carcinoma patients in China. Immunotherapy is used to treat an increasing number of ESCC patients in clinical practice. This study aims to understand the molecular heterogeneity and the tumor immune microenvironment of ESCC for designing novel immunotherapies to improve response and outcomes. We identified two molecular subtypes associated with prognosis, immune-related pathways, and tumor microenvironment. In an independent cohort of Chinese ESCC patients treated with immunotherapy, the response rate of the S1 subtype is significantly higher than the S2 subtype. These findings provide a new perspective on the molecular subtyping for ESCC and a biological rationale for novel therapeutic intervention in a specific subgroup of ESCC that could potentially be translated into clinical practice both diagnostically and therapeutically to benefit ESCC patients.

Abstract

Background: Immunotherapy is recently being used to treat esophageal squamous cell carcinoma (ESCC); however, response and survival benefits are limited to a subset of patients. A better understanding of the molecular heterogeneity and tumor immune microenvironment in ESCC is needed for improving disease management. Methods: Based on the DNA methylation and gene expression profiles of ESCC patients, we identify molecular subtypes of patients and construct a predictive model for subtype classification. The clinical value of molecular subtypes for the prediction of immunotherapy efficacy is assessed in an independent validation cohort of Chinese ESCC patients who receive immunotherapy. Results: We identify two molecular subtypes of ESCC (S1 and S2) that are associated with distinct immune-related pathways, tumor microenvironment and clinical outcomes. Accordingly, S2 subtype patients had a poorer prognosis. A 15-gene expression signature is developed to classify molecular subtypes with an overall accuracy of 94.7% (89/94, 95% CI: 0.880–0.983). The response rate of immunotherapy is significantly higher in the S1 subtype than in the S2 subtype patients (68.75% vs. 25%, p = 0.028). Finally, potential target drugs, including mitoxantrone, are identified for treating patients of the S2 subtype. Conclusions: Our findings demonstrated that the identified molecular subtypes constitute a promising prognostic and predictive biomarker to guide the clinical care of ESCC patients.

Bis(chloroacetamidino)-Derived Heteroarene-Fused Anthraquinones Bind to and Cause Proteasomal Degradation of tNOX, Leading to c-Flip Downregulation and Apoptosis in Oral Cancer Cells

Simple Summary

New-generation anthraquinone derivatives attached with different heterocycles and bearing chloroacetamidines in the side chains have been synthesized to reduce side effects and drug resistance. In this study, we identified the cellular target of the studied compounds through ligand binding assays and in silico simulations. Our results illustrate that the studied compounds bound to and targeted the tumor-associated NADH oxidase (tNOX) in oral cancer cells. tNOX is a growth-related protein and is found to be expressed in cancer cells but not in non-transformed cells, and its knockdown by RNA interference in tumor cells overturns cancer phenotypes, supporting its role in cellular growth. We also identified that tNOX bound to the studied compounds and underwent degradation, which was correlated with apoptosis induction in oral cancer cells.

Abstract

Anthraquinone-based intercalating compounds, namely doxorubicin and mitoxantrone, have been used clinically based on their capacity to bind DNA and induce DNA damage. However, their applications have been limited by side effects and drug resistance. New-generation anthraquinone derivatives fused with different heterocycles have been chemically synthesized and screened for higher anticancer potency. Among the compounds reported in our previous study, 4,11-bis(2-(2-chloroacetamidine)ethylamino)anthra[2,3-b]thiophene-5,10-dione dihydrochloride (designated 2c) was found to be apoptotic, but the direct cellular target responsible for the cytotoxicity remained unknown. Here, we report the synthesis and anticancer properties of two other derivatives, 4,11-bis(2-(2-chloroacetamidine)ethylamino)naphtho[2,3-f]indole-5,10-dione dihydrochloride (2a) and 4,11-bis(2-(2-chloroacetamidine)ethylamino)-2-methylanthra[2,3-b]furan-5,10-dione dihydrochloride (2b). We sought to identify and validate the protein target(s) of these derivatives in oral cancer cells, using molecular docking simulations and cellular thermal shift assays (CETSA). Our CETSA results illustrate that these derivatives targeted the tumor-associated NADH oxidase (tNOX, ENOX2), and their direct binding downregulated tNOX in p53-functional SAS and p53-mutated HSC-3 cells. Interestingly, the compounds targeted and downregulated tNOX to reduce SIRT1 deacetylase activity and increase Ku70 acetylation, which triggers c-Flip ubiquitination and induces apoptosis in oral cancer cells. Together, our data highlight the potential value of these heteroarene-fused anthraquinones in managing cancer by targeting tNOX and augmenting apoptosis.

Cannabidiol Interacts Antagonistically with Cisplatin and Additively with Mitoxantrone in Various Melanoma Cell Lines-An Isobolographic Analysis

The medical application of cannabidiol (CBD) has been gathering increasing attention in recent years. This non-psychotropic cannabis-derived compound possesses antiepileptic, antipsychotic, anti-inflammatory and anxiolytic properties. Recent studies report that it also exerts antineoplastic effects in multiple types of cancers, including melanoma. In this in vitro study we tried to reveal the anticancer properties of CBD in malignant melanoma cell lines (SK-MEL 28, A375, FM55P and FM55M2) administered alone, as well as in combination with mitoxantrone (MTX) or cisplatin (CDDP). The effects of CBD on the viability of melanoma cells were measured by the MTT assay; cytotoxicity was determined in the LDH test and proliferation in the BrdU test. Moreover, the safety of CBD was tested in human keratinocytes (HaCaT) in LDH and MTT tests. Results indicate that CBD reduces the viability and proliferation of melanoma-malignant cells and exerts additive interactions with MTX. Unfortunately, CBD produced antagonistic interaction when combined with CDDP. CBD does not cause significant cytotoxicity in HaCaT cell line. In conclusion, CBD may be considered as a part of melanoma multi-drug therapy when combined with MTX. A special attention should be paid to the combination of CBD with CDDP due to the antagonistic interaction observed in the studied malignant melanoma cell lines.

Image-Based Annotation of Chemogenomic Libraries for Phenotypic Screening

Phenotypical screening is a widely used approach in drug discovery for the identification of small molecules with cellular activities. However, functional annotation of identified hits often poses a challenge. The development of small molecules with narrow or exclusive target selectivity such as chemical probes and chemogenomic (CG) libraries, greatly diminishes this challenge, but non-specific effects caused by compound toxicity or interference with basic cellular functions still pose a problem to associate phenotypic readouts with molecular targets. Hence, each compound should ideally be comprehensively characterized regarding its effects on general cell functions. Here, we report an optimized live-cell multiplexed assay that classifies cells based on nuclear morphology, presenting an excellent indicator for cellular responses such as early apoptosis and necrosis. This basic readout in combination with the detection of other general cell damaging activities of small molecules such as changes in cytoskeletal morphology, cell cycle and mitochondrial health provides a comprehensive time-dependent characterization of the effect of small molecules on cellular health in a single experiment. The developed high-content assay offers multi-dimensional comprehensive characterization that can be used to delineate generic effects regarding cell functions and cell viability, allowing an assessment of compound suitability for subsequent detailed phenotypic and mechanistic studies.

Mitoxantrone-Loaded Nanoferritin Slows Tumor Growth and Improves the Overall Survival Rate in a Subcutaneous Pancreatic Cancer Mouse Model

Pancreatic cancer (PC) represents an intriguing topic for researchers. To date, the prognosis of metastasized PC is poor with just 7% of patients exceeding a five-year survival period. Thus, molecular modifications of existing drugs should be developed to change the course of the disease. Our previously generated nanocages of Mitoxantrone (MIT) encapsulated in human H-chain Ferritin (HFt), designated as HFt-MP-PASE-MIT, has shown excellent tumor distribution and extended serum half-life meriting further investigation for PC treatment. Thus, in this study, we used the same nano-formulation to test its cytotoxicity using both in vitro and in vivo assays. Interestingly, both encapsulated and free-MIT drugs demonstrated similar killing capabilities on PaCa44 cell line. Conversely, in vivo assessment in a subcutaneous PaCa44 tumor model of PC demonstrated a remarkable capability for encapsulated MIT to control tumor growth and improve mouse survival with a median survival rate of 65 vs. 33 days for loaded and free-MIT, respectively. Interestingly, throughout the course of mice treatment, MIT encapsulation did not present any adverse side effects as confirmed by histological analysis of various murine tissue organs and body mass weights. Our results are promising and pave the way to effective PC targeted chemotherapy using our HFt nanodelivery platforms.

Reversing pathology in a preclinical model of Alzheimer's disease by hacking cerebrovascular neoangiogenesis with advanced cancer therapeutics

BACKGROUND

Cognitive decline leading to dementia, accompanied by the accumulation of amyloid-beta (Aβ) in neuritic plaques together with the appearance of neurofibrillary tangles (NFT) composed of hyperphosphorylated tau protein (tau), are previously noted hallmarks of Alzheimer's disease (AD). We previously discovered hypervascularity in brain specimens from AD patients and consistent with this observation, we demonstrated that overexpression of Aβ drives cerebrovascular neoangiogenesis leading to hypervascularity and coincident tight-junction disruption and blood-brain barrier (BBB) leakiness in animal models of AD. We subsequently demonstrated that amyloid plaque burden and cerebrovascular pathogenesis subside when pro-angiogenic Aβ levels are reduced. Based on these data, we propose a paradigm of AD etiology where, as a compensatory response to impaired cerebral blood flow (CBF), Aβ triggers pathogenic cerebrovascular neoangiogenesis that underlies the conventional hallmarks of AD. Consequently, here we present evidence that repurposing anti-cancer drugs to modulate cerebrovascular neoangiogenesis, rather than directly targeting the amyloid cascade, may provide an effective treatment for AD and related vascular diseases of the brain.

METHODS

We explored whether the anti-cancer drug, Axitinib, a small molecule tyrosine kinase inhibitor that targets vascular endothelial growth factor receptors (VEGFR) can inhibit aberrant cerebrovascular neoangiogenic changes, reduce Aβ deposits and reverse cognitive decline in an animal model of AD. One month post-treatment with Axitinib, we employed a battery of tests to assess cognition and memory in aged Tg2576 AD mice and used molecular analysis to demonstrate reduction of amyloid plaques, BBB leakage, hypervascularity and associated disease pathology.

FINDINGS

Targeting the pro-angiogenic pathway in AD using the cancer drug, Axitinib, dramatically reduced cerebrovascular neoangiogenesis, restored BBB integrity, resolved tight-junction pathogenesis, diminishes Aβ depositions in plaques and effectively restores memory and cognitive performance in a preclinical mouse model of AD.

INTERPRETATION

Modulation of neoangiogenesis, in an analogous approach to those used to treat aberrant vascularization in cancer and also in the wet form of age-related macular degeneration (AMD), provides an alternative therapeutic strategy for intervention in AD that warrants clinical investigation.

FUNDING

None.

Estrone-targeted liposomes for mitoxantrone delivery via estrogen receptor: In vivo targeting efficacy, antitumor activity, acute toxicity and pharmacokinetics

Estrogen receptor (ER) is a potential target receptor for ER-positive cancer therapy including breast cancers, gastric cancers, and human acute myeloblastic leukaemia. In order to reduce the side-effects of mitoxantrone (MTO), estrone-targeted liposomes for MTO delivery via ER were designed for selectively targeting cancer cells. In previous studies, MTO-loaded estrogen receptor targeted and sterically stabilized liposome (ES-SSL-MTO; ES: estrone, is known to bind the ER) had been synthesized and showed a very high antiproliferative effect with IC₅₀ value of 0.7 ng/mL. Based on these, further studies including in vivo targeting efficacy and antitumor activity, acute toxicity and pharmacokinetics of MTO liposomes were carried out. The results showed SSL (sterically stabilized liposome, PEGylated liposome, PEG: Polyethylene Glycol) could reduce drug metabolism, improve the stability of liposomes, prolong in vivo circulation time of drugs, reduce the toxicity of MTO. But SSL could not be enriched in tumor tissues. However, estrone (ES)-targeted liposomes could be delivered to tumor sites. ES-SSL could effectively enter into ER-expressing tumor cellsand be accumulated, prolong the circulation time in vivo, reduce side effects of drug. ES-SSL-MTO could provide higher bioavailability than MTO, enhance the anti-tumor effect and the safety of MTO, reduce the toxicity and side effects of MTO and improve the therapeutic effect of MTO. These facts proved ES-SSL is a useful tumor-targeting drug delivery system for MTO.

Glucosamine attenuates drug resistance in Mitoxantrone-resistance breast cancer cells

OBJECTIVES

This study was aimed at investigating the cytotoxicity and multi-drug resistance (MDR) reversal effect of Glucosamine (GlcN) on resistant BCRP-overexpressing breast cancer MCF-7/MX cells.

METHODS

After confirming the overexpression of BCRP, the cytotoxicity and MDR reversing potential of GlcN on MCF-7/MX mitoxantrone-resistant and MCF-7 sensitive breast cancer cells were assessed via MTT assay. The effects of GlcN on mitoxantrone accumulation were analyzed through flow cytometry. Finally, the expression of BCRP and Epithelial-Mesenchymal Transition (EMT)-related markers following the exposure to GlcN were assessed by real-time RT-PCR.

KEY FINDINGS

This study showed that glucosamine had an inhibitory effect on the proliferation of human breast cancer cells. The respective IC50 values for MCF-7/MX cells following exposure to mitoxantrone (MX) in the presence of GlcN (0, 0.5 and 1 mm) for 72 h were 3.61 ± 0.21, 0.598 ± 0.041 and 0.284 ± 0.016 μm, respectively. Furthermore, GlcN reduced the expression of BCRP mRNA without any significant effect on EMT-related markers in breast cancer cells.

CONCLUSIONS

These results proposed that glucosamine as a natural sugar could down regulate the BCRP expression and increased MX cytotoxicity in breast cancer cells.

Overcoming the protein corona in chitosan-based nanoparticles

Numerous properties of chitosan have led to its extensive use in the formulation of nanomaterials for drug delivery. However, the cationic surface of chitosan-based nanoparticles adsorbs proteins upon exposure to biological fluids, forming a phenomenon known as 'protein corona'. This causes several effects such as decreased bioavailability and limited in vivo clinical applications of chitosan nanoparticles. Understanding and overcoming the effects of protein adsorption on chitosan nanoparticles is key for drug delivery purposes. This review focuses on the strategies implemented to increase the stability of chitosan nanoparticles in the systemic circulation by averting the formation of protein corona and the limitations of PEGylation.

A single-center, self-controlled, phase I clinical trial of mitoxantrone hydrochloride injection for lymph tracing for sentinel lymph node identification of breast cancer

Background

Mitoxantrone hydrochloride injection for lymph tracing (MHI) is a novel lymphatic tracer for sentinel lymph node (SLN) in patients with early breast cancer but exhibited remarkable liver, kidney, and hematologic toxicities in previous studies. Here, the pharmacokinetics and pharmacodynamics profiles of MHI were evaluated to surmise safety and tolerability.

Methods

Phase 1 open-label, single center, and dose escalation study was performed. Ten patients with invasive breast cancer received 0.5, 1.0, or 2.0 mL of MHI into the breast tissues surrounding the tumor for lymphatic mapping. All of these patients were injected with 2 mCi nuclide-labeled sulfur colloid as a self-control 24 to 48 hours before surgery. Safety was assessed by the incidence of adverse events graded by the National Cancer Institute Common Terminology Criteria, version 4.0.3 (CTCAE4.0.3). Blood samples for pharmacokinetic analyses were collected before and after administration at 15, 30, 60, 120, and 240 min of the injection of MHI.

Results

Up to the cutoff date of the study (Aug 8, 2018), no dose-limiting toxic effects or obvious allergic reactions were observed. Only one case of an adverse event was certainly related to MHI, where it caused blue discoloration of the local skin over the injection site after the operation, but this stain gradually went away. The peak level of MHI was achieved after 15-30 min post injection and completely eliminated from the plasma after 60 min. There were no significant differences in the number of lymph nodes detected by MHI and radioactive colloid. Only one patient with lymph node macrometastases had no SLN detected by either the radioactive colloid or the MHI.

Conclusions

At a dose of up to 2.0 mL, MHI was well tolerated and safe for conducting SLN biopsies in patients with breast cancer. Although there was a case with blue discoloration of the local skin over the injection site after the operation, and remained for a short period of time, but the overall safety was acceptable. Here, we approached a novel SLN tracing slant; however, more investigations of MHI should be performed for further evaluations. (Chinadrugtrials.org.cn number: CXHL1301201, Date of registration: October 12, 2015.).

Establishment and characterization of a novel cell line, NCC-TGCT1-C1, derived from a patient with tenosynovial giant cell tumor

Tenosynovial giant cell tumor (TGCT) is a mesenchymal tumor arising from the synovium of tendon sheath and joints, characterized by translocation t(1;2)(p13;q37). Clinical behaviors of TGCT range from favorable to locally aggressive and further research is required to lead the identification of novel therapeutic avenues for TGCT. Patient-derived cell lines are an indispensable tool for interrogating molecular mechanisms underlying the progression of disease. However, only one TGCT cell line is currently available from cell banks, and a paucity of adequate patient-derived cells hinders basic and translational research. This study aimed to establish a novel cell line of TGCT. To this end, a novel cell line, NCC-TGCT1-C1 was established from the primary tumor tissue of a 40-year-old female patient with TGCT. The cells exhibited translocation t(1;2)(p13;q37), generating COL6A3-CSF1 fusion gene. The cells were maintained as a monolayer culture through more than 30 passages over 12 months. The cells exhibited continuous growth and the ability for spheroid formation and invasion. When used in a high-throughput assay to evaluate the anti-proliferative effects of 164 anticancer drugs, the cells responded strongly to a kinase inhibitor such as gefitinib, and mitoxantrone. Our results indicate that the novel TGCT cell line, designated NCC-TGCT1-C1, was successfully established and could be used to study TGCT development and the effects of anticancer agents.

A case of mitoxantrone extravasation

Introduction

Mitoxantrone is a chemotherapeutic agent approved for various diseases. The literature has been conflicting in classifying mitoxantrone as a vesicant or irritant.

Case report

We report a patient who had an extravasation of mitoxantrone. Mitoxantrone was administered in 50 ml normal saline. After mitoxantrone was completely infused, the site appeared edematous and the blue color of mitoxantrone developed beneath the skin. The patient reported pain. Management and outcome: The extravasation was treated with dexrazoxane and cold compresses. The pain improved each day. However, blistering developed five weeks later and the patient ultimately required surgical intervention for debridement and grafting.

Discussion

Extravasation events are rare and there are few controlled studies. Because of the similarities in chemical structures and mechanism of actions between mitoxantrone and anthracyclines, mitoxantrone extravasation is often treated similar to anthracyclines. Mitoxantrone's classification is unclear, as some literature classifies it as a vesicant and others as an irritant. Our case supports the categorization of mitoxantrone as a vesicant.

DUBbing Down Translation: The Functional Interaction of Deubiquitinases with the Translational Machinery

Cancer cells revamp the regulatory processes that control translation to induce tumor-specific translational programs that can adapt to a hostile microenvironment as well as withstand anticancer therapeutics. Translational initiation has been established as a common downstream effector of numerous deregulated signaling pathways that together culminate in prooncogenic expression. Other mechanisms, including ribosomal stalling and stress granule assembly, also appear to be rewired in the malignant phenotype. Therefore, better understanding of the underlying perturbations driving oncogenic translation in the transformed state will provide innovative therapeutic opportunities. This review highlights deubiquitinating enzymes that are activated/dysregulated in hematologic malignancies, thereby altering the translational output and contributing to tumorigenesis.

Preparation and purification of novel phosphatidyl prodrug and performance modulation of phosphatidyl nanoprodrug

Background

A novel phosphatidyl nanoprodrug system can be selectively released parent drugs in cancer cells, triggered by the local overexpression of phospholipase D (PLD). This system significantly reduces the intrinsic disadvantages of conventional chemotherapeutic drugs. However, the separation and purification processes of phosphatidyl prodrug, the precursor of phosphatidyl nanoprodrug, have not been established, and the preparation of nanocrystals with good stability and tumor-targeting capability is still challenging.

Results

In this study, we established a successive elution procedure for the phosphatidyl prodrug—phosphatidyl mitoxantrone (PMA), using an initial ten-bed volume of chloroform/methanol/glacial acetic acid/water (26/10/0.8/0.7) (v/v/v/v) followed by a five-bed volume (26/10/0.8/3), with which purity rates of 96.93% and overall yields of 50.35% of PMA were obtained. Moreover, to reduce the intrinsic disadvantages of conventional chemotherapeutic drugs, phosphatidyl nanoprodrug—PMA nanoprodrug (NP@PMA)—was prepared. To enhance their stability, nanoparticles were modified with polyethylene glycol (PEG). We found that nanoprodrugs modified by PEG (NP@PEG–PMA) were stably present in RPMI-1640 medium containing 10% FBS, compared with unmodified nanoprodrug (NP@PMA). To enhance active tumor-targeting efficiency, we modified nanoparticles with an arginine-glycine-aspartic acid (RGD) peptide (NP@RGD–PEG–PMA). In vitro cytotoxicity assays showed that, compared with the cytotoxicity of NP@PEG–PMA against tumor cells, that of NP@RGD–PEG–PMA was enhanced. Thus, RGD modification may serve to enhance the active tumor-targeting efficiency of a nanoprodrug, thereby increasing its cytotoxicity.

Conclusions

A process for the preparation and purification of novel phosphatidyl prodrugs was successfully established, and the nanoprodrug was modified using PEG for enhanced nanoparticle stability, and using RGD peptide for enhanced active tumor-targeting efficiency. These procedures offer considerable potential in the development of functional antitumor prodrugs.

Delivery of mitoxantrone using a plant virus-based nanoparticle for the treatment of glioblastomas

Mitoxatrone (MTO), an antineoplastic chemotherapeutic, has potent activity against the most common and agressive type of primary brain tumor, glioblastoma multiforme (GBM). However, its poor penetration through the blood brain barrier, and cardiotoxic side effects from systemic delivery limit its effectiveness for clinical treatment. To address these limitations, we utilize a plant virus-based nanoparticle, cowpea mosaic virus (CPMV), to deliver MTO to treat GBM. In this work, we loaded MTO into the interior cavity of CPMV (CPMV-MTO) through diffusion through its pores. We report the uptake of CPMV-MTO in glioma cells and demonstrate its cytotoxic effects in vitro as a solo therapy, and in combination with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). These results reveal the potential for this plant virus-based nanoparticle platform for the treatment of GBM.

Induction or escalation therapy for patients with multiple sclerosis?

The concept of induction followed by a long-term maintenance treatment has attracted much attention for the treatment of multiple sclerosis over the 30 past years. It was first demonstrated by the combination of induction therapy with mitoxantrone (six-monthly courses) followed by maintenance therapy with an immunomodulatory treatment such as an interferon-β or glatiramer acetate. Long-term observational studies confirmed that this therapeutic regimen provides a rapid reduction in disease activity and sustained disease control up to at least five years in 60% of patients. A better treatment response was observed in patients with early signs of aggressive disease, as shown in randomised studies (using six-monthly 12mg/m² of mitoxantrone intravenously at a cumulative dose of 72mg/m², followed by an interferon-β) as well as in long-term observational studies. But the safety profile of mitoxantrone make it more particularly suitable for young patients with frequent early relapses with incomplete recovery and multiple gadolinium-enhancing T1 lesions or spinal cord lesions on magnetic resonance imaging. More recently approved, the second candidate for an induction strategy is alemtuzumab: phases II and III randomised studies showed the superiority of alemtuzumab 12mg per day given intravenously for only five days and repeated for 3 days one year later, compared with interferon-β three times a week. Like with mitoxantrone, results supported the concept of long-term benefit after a short induction rather than escalation, in a subset of patients with early very active MS, with a sustained control of the disease for up to 7 years in 60% of patients in the phase III extension studies and in a long-term observational study. On the contrary, when alemtuzumab was first studied later in the disease course, results were disappointing. However, the risk of developing manageable but potentially severe systemic autoimmune diseases within the years following the last course of alemtuzumab make it, like mitoxantrone, more suitable for patients with early aggressive MS. More recently, cladribine an oral immunosuppressant, showed interesting results in a phase III study extension suggesting its potential induction effect, since after two cycles of treatment (5 days repeated 1 month later) at one year of interval, the remained low up to 4 years of follow-up, in the absence of any new treatment. However, today other immunosuppressive drugs have proved to be strongly and rapidly efficacious in treating highly active MS patients but through a mechanism of continuous immunosuppression (i.e., natalizumab and ocrelizumab). Indeed, disease activity can reappear rapidly after stopping these drugs, sometimes associated with a rebound of the inflammatory process, which is the contrary of a mechanism of induction that is associated with a remnant effect. Taking into account advantages and disadvantages of the different DMDs, which enriched the today therapeutic arsenal for MS, we propose in this paper some algorithms summarizing our reflexion about using an escalation strategy or an induction strategy according to disease course and activity.

Bbr 2778, an Aza-anthracenedione Endowed with Preclinical Anticancer Activity and Lack of Delayed Cardiotoxicity

With the aim to provide second-generation anthracenedione analogues endowed with reduced side effects and a wider spectrum of action than mitoxantrone and doxorubicin, a large number of new molecules bearing nitrogen atoms in the chromophore was synthesized and screened in vitro and in vivo. From this screening, BBR 2778 (6,9-bis[(2-aminoethyl)amino] benzo[g]isoquinoline-5,10-dione dimaleate) emerged as the most interesting compound. BBR 2778 was tested in vitro on several murine and human tumor cell lines and showed cytotoxic potency lower than that of mitoxantrone and doxorubicin. BBR 2778 was more cytotoxic in leukemia and lymphoma cell lines than in solid tumor cell lines. Although against in vivo models BBR 2778 was less potent than mitoxantrone and doxorubicin, its antitumor activity was equal or superior (in certain tumor models) to that of the above standard compounds. In particular, BBR 2778 was curative against L1210 murine leukemia and YC-8 murine lymphoma. Moreover, it showed an antitumor activity comparable to that of mitoxantrone and doxorubicin on solid tumors. No cardiotoxic effect of BBR 2778 in animals not pretreated with anthracyclines was observed compared to standards. In light of its spectrum of activity and marked efficacy against lymphomas and leukemias over a wide dose range, together with its lack of delayed cardiotoxicity, BBR 2778 has been entered in clinical studies.

Isolation and structural analysis of the covalent adduct formed between a bis-amino mitoxantrone analogue and DNA: a pathway to major-minor groove cross-linked adducts

The major covalent adduct formed between a ¹³C-labelled formaldehyde activated bis-amino mitoxantrone analogue (WEHI-150) and the hexanucleotide d(CG^5MeCGCG)₂ has been isolated by HPLC chromatography and the structure determined by NMR spectroscopy. The results indicate that WEHI-150 forms one covalent bond through a primary amine to the N-2 of the G₂ residue, with the polycyclic ring structure intercalated at the ^5MeC₃pG₄/G₁₀p^5MeC₉ site. Furthermore, the WEHI-150 aromatic ring system is oriented approximately parallel to the long axis of the base pairs, with one aliphatic side-chain in the major groove and the other side-chain in the minor groove. This study indicates that mitoxantrone derivatives like WEHI-150 should be capable of forming major-minor groove cross-linked adducts that will likely produce considerably different intracellular biological properties compared to known anthracycline and anthracenedione anticancer drugs.

Selected anthraquinones as potential free radical scavengers and P-glycoprotein inhibitors

In this article, we estimated the scavenger capacity of six selected anthraquinones toward free radicals and their efficacy as inhibitors of P-glycoproteins.

Pituitary adenylate cyclase-activating polypeptide (PACAP) protects against mitoxantrone-induced cardiac injury in mice

Mitoxantrone (MXT) is an androstenedione that is used to treat cancers and progressive forms of multiple sclerosis; however, its use is limited by its cardiotoxicity. Pituitary adenylate cyclase activating polypeptide (PACAP) is a member of the secretin/growth hormone-releasing hormone/vasoactive intestinal peptide family and has many functions, including cytoprotection and immunosuppression. We tested the hypothesis that PACAP can protect against MXT-induced cardiotoxicity in mice. Female BALB/c mice were treated once weekly for 4 weeks with saline (n=14) or MXT (3mg/kg, i.p.; n=14). Half of the mice in each group received PACAP (10μg, i.p.) 1h before and 24 and 48h after MXT, while the remaining mice received injections of saline on the same schedule. Echocardiography was used to assess cardiac structure and function. In mice treated with MXT and saline, body weight was significantly reduced after the third dose of MXT. PACAP significantly attenuated the reduction in body weight; however, the weights did not return to control level. Compared to controls, MXT-treated mice had significantly increased left ventricular (LV) diameter and LV volume and decreased LV posterior wall thickness. Fractional shortening (FS) and ejection fraction (EF) were also significantly decreased. Treatment with PACAP prevented MXT-induced LV dilation and significantly attenuated the reductions in FS and EF, although FS and EF did not return to control level. PACAP38 did not prevent MXT-induced decreases in LV posterior wall thickness. MXT dose-dependently decreased the viability of cultured U937 (human leukemia) cells; PACAP did not protect cultured U937 cells from MXT-mediated cell death. In conclusion, PACAP can attenuate MXT-mediated LV dilation and dysfunction in mice.

DNA topoisomerase-targeting chemotherapeutics: what's new?

To resolve the topological problems that threaten the function and structural integrity of nuclear and mitochondrial genomes and RNA molecules, human cells encode six different DNA topoisomerases including type IB enzymes (TOP1 and TOP1mt), type IIA enzymes (TOP2α and TOP2β) and type IA enzymes (TOP3α and TOP3β). DNA entanglements and the supercoiling of DNA molecules are regulated by topoisomerases through the introduction of transient enzyme-linked DNA breaks. The covalent topoisomerase-DNA complexes are the cellular targets of a diverse group of cancer chemotherapeutics, which reversibly stabilize these reaction intermediates. Here we review the structure-function and catalytic mechanisms of each family of eukaryotic DNA topoisomerases and the topoisomerase-targeting agents currently approved for patient therapy or in clinical trials, and highlight novel developments and challenges in the clinical development of these agents.

Encapsulation of Mitoxantrone within Cucurbit[8]uril Decreases Toxicity and Enhances Survival in a Mouse Model of Cancer

Mitoxantrone was efficiently encapsulated within cucurbit[8]uril in a 2:1 complex where the two mitoxantrone molecules were symmetrically located through both portals of a cucurbit[8]uril cage. The novel complex facilitates increased mitoxantrone uptake in mouse breast cancer cells and decreases the toxicity of the drug in healthy mice. In an orthotopic mouse model of metastatic breast cancer the complex still maintains in vivo anticancer activity compared to the free drug, yet provides a statistically significant increase in the survival of these mice compared to conventional mitoxantrone treatment. This new low toxicity formulation offers the possibility to increase mitoxantrone dose and thus maximize efficacy while managing the dose limiting side effects.

Oestrone-targeted liposomes for mitoxantrone delivery via oestrogen receptor - synthesis, physicochemical characterization and in-vitro evaluation

OBJECTIVES

Targeted delivery of mitoxantrone (MTO, an anthraquinone drug with high antitumour effect) may be achieved using a novel nanoparticulate delivery system via binding the oestrogen receptor (ER, highly expressed in a variety of human tumours).

METHODS

A novel liposomal nanoparticle (NP) was developed using a conjugate derived from 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino (polyethylene glycol)-2000] (DSPE-PEG₂₀₀₀ -NH₂ ) and oestrone (ES, is known to bind the ER) to produce an ES-targeted PEGylated liposome (ES-SSL). The resulting targeted NP was loaded with MTO to produce a targeted liposome-MTO formulation (ES-SSL-MTO).

KEY FINDINGS

The targeted formulation (~140 nm, 1.5 mV) achieved over 95% drug encapsulation efficiency and a favourable stability at 4, 25 and 37 °C up to 48 h. The flow cytometric data indicated that cellular uptake of ES-SSL into human leukaemia HL-60 cells was mediated via binding the oestrogen receptor. In addition, the ES-SSL-MTO significantly reduced the growth of HL-60 cells.

CONCLUSIONS

Our results provide a proof of principle that ES-modified PEGylated liposomes can target the ER, thereby potentially improving the therapeutic benefits in ER-overexpressed tumours.

Cytoskeletal reorganization and cell death in mitoxantrone-treated lung cancer cells

The aim of this study was to investigate the cytotoxic effect of mitoxantrone on two human non-small cell lung cancer cell lines, A549 (p53+) and H1299 (p53-). To our knowledge, this is the first study to evaluate the impact of MXT on the organization of cytoskeletal proteins. Analyses were performed using fluorescence and transmission electron microscopy, spectrophotometric techniques, flow cytometry and Western blotting. It was shown that H1299 cells are significantly more sensitive to mitoxantrone than the A549 cell line, and that the growth-inhibitory effect of the drug is dose-dependent only after longer incubation. The observed presence of ring-like microtubule structures and mitochondria surrounding the nuclei of H1299 cells could be a manifestation of increased tubulin polymerization requiring large amounts of energy, whereas the loss of actin stress fibers was presumably not the cause but rather the consequence of cell death induction. Treatment with mitoxantrone also led to the appearance of structures resembling agresomes in H1299 cells and to nucleolar segregation in both cell lines. It was demonstrated that cells arrested in the S phase were most susceptible to cell death induction, and that triggered intracellular changes led mainly to apoptosis. High concentrations induced necrosis and some H1299 cells exhibited morphological features of mitotic catastrophe.

Formation and Biological Targets of Quinones: Cytotoxic versus Cytoprotective Effects

Quinones represent a class of toxicological intermediates, which can create a variety of hazardous effects in vivo including, acute cytotoxicity, immunotoxicity, and carcinogenesis. In contrast, quinones can induce cytoprotection through the induction of detoxification enzymes, anti-inflammatory activities, and modification of redox status. The mechanisms by which quinones cause these effects can be quite complex. The various biological targets of quinones depend on their rate and site of formation and their reactivity. Quinones are formed through a variety of mechanisms from simple oxidation of catechols/hydroquinones catalyzed by a variety of oxidative enzymes and metal ions to more complex mechanisms involving initial P450-catalyzed hydroxylation reactions followed by two-electron oxidation. Quinones are Michael acceptors, and modification of cellular processes could occur through alkylation of crucial cellular proteins and/or DNA. Alternatively, quinones are highly redox active molecules which can redox cycle with their semiquinone radical anions leading to the formation of reactive oxygen species (ROS) including superoxide, hydrogen peroxide, and ultimately the hydroxyl radical. Production of ROS can alter redox balance within cells through the formation of oxidized cellular macromolecules including lipids, proteins, and DNA. This perspective explores the varied biological targets of quinones including GSH, NADPH, protein sulfhydryls [heat shock proteins, P450s, cyclooxygenase-2 (COX-2), glutathione S-transferase (GST), NAD(P)H:quinone oxidoreductase 1, (NQO1), kelch-like ECH-associated protein 1 (Keap1), IκB kinase (IKK), and arylhydrocarbon receptor (AhR)], and DNA. The evidence strongly suggests that the numerous mechanisms of quinone modulations (i.e., alkylation versus oxidative stress) can be correlated with the known pathology/cytoprotection of the parent compound(s) that is best described by an inverse U-shaped dose-response curve.

Mitoxantrone-induced cardiotoxicity

Anthracycline-induced cardiotoxicity has been well documented in the literature. Doxorubicin has been most commonly implicated; however, electrocardiogram changes have also been reported with the use of mitoxantrone. We report a case of a 55-year-old female with recurrent acute myelogenous leukemia who underwent reinduction therapy with mitoxantrone and etoposide daily for five doses. Nearing completion of her fifth mitoxantrone dose, she complained of chest tightness and developed bradycardia. Her symptoms resolved with discontinuation of the agent; however, upon rechallenge, she again developed sinus bradycardia with premature ventricular contractions and a corrected QT interval of 0.499 seconds. Clinicians should be aware of the risk factors for mitoxantrone-induced cardiotoxicity and monitor their patients appropriately while on therapy.