Multifunctional platinum(IV) complex bearing HDAC inhibitor and biotin moiety exhibits prominent cytotoxicity and tumor-targeting ability

Advancements in platinum-based anticancer drug development: A comprehensive review of strategies, discoveries, and future perspectives

Platinum-based anticancer drugs have been at the forefront of cancer chemotherapy, with cisplatin emerging as a pioneer in the treatment of various malignancies. This review article provides a comprehensive overview of the evolution of platinum-based anticancer therapeutics, focusing on the development of cisplatin, platinum(IV) prodrugs, and the integration of photodynamic therapy (PDT) for enhanced cancer treatment results. The first section of the review delves into the historical context and molecular mechanisms underlying the success of cisplatin, highlighting its DNA binding properties and subsequent interference with cellular processes. Despite its clinical efficacy, the inherent limitations, including dose-dependent toxicities and acquired resistance, accelerated the exploration of novel platinum derivatives. This led to the emergence of platinum(IV) prodrugs, designed to overcome resistance mechanisms and enhance selectivity through targeted drug delivery. The subsequent section provides an in-depth analysis of the principles of design and structural modifications employed in the development of platinum(IV) prodrugs. The transitions to the incorporation of photodynamic therapy (PDT) stands out as a synergistic approach to platinum-based anticancer treatment. The photophysical properties of platinum complexes are discussed in the context of their potential application in PDT, emphasizing on combined cytotoxic effects of platinum-based drugs and light-induced reactive oxygen species generation. This dual-action approach holds great promise for overcoming the limitations of traditional chemotherapy as well as producing superior therapeutic outcomes. Overall, the present report explores the latest developments in the development and use of platinum complexes, highlighting novel strategies such combination treatments, targeted delivery methods, and the generation of multifunctional complexes. It also provides a comprehensive overview of the current landscape while proposing future directions for the development of next-generation platinum-based anticancer therapeutics.

Mechanisms of myocardial toxicity of antitumor drugs and potential therapeutic strategies: A review of the literature

With the successive development of chemotherapy drugs, good results have been achieved in clinical application. However, myocardial toxicity is the biggest challenge. Anthracyclines, immune checkpoint inhibitors, and platinum drugs are widely used. Targeted drug delivery, nanomaterials and dynamic imaging evaluation are all emerging research directions. This article reviews the recent literature on the use of targeted nanodrug delivery and imaging techniques to evaluate the myocardial toxicity of antineoplastic drugs, and discusses the potential mechanisms.

NIR Light and GSH Dual-Responsive Upconversion Nanoparticles Loaded with Multifunctional Platinum(IV) Prodrug and RGD Peptide for Precise Cancer Therapy

Platinum(II) drugs as a first-line anticancer reagent are limited by side effects and drug resistance. Stimuli-responsive nanosystems hold promise for precise spatiotemporal manipulation of drug delivery, with the aim to promote bioavailability and minimize side effects. Herein, a multitargeting octahedral platinum(IV) prodrug with octadecyl aliphatic chain and histone deacetylase inhibitor (phenylbutyric acid, PHB) at axial positions to improve the therapeutic effect of cisplatin was loaded on the upconversion nanoparticles (UCNPs) through hydrophobic interaction. Followed attachment of DSPE-PEG2000 and arginine-glycine-aspartic (RGD) peptide endowed the nanovehicles with high biocompatibility and tumor specificity. The fabricated nanoparticles (UCNP/Pt(IV)-RGD) can be triggered by upconversion luminescence (UCL) irradiation and glutathione (GSH) reduction to controllably release Pt(II) species and PHB, inducing profound cytotoxicity. Both in vitro and in vivo experiments demonstrated that UCNP/Pt(IV)-RGD exhibited remarkable antitumor efficiency, high tumor-targeting specificity, and real-time UCL imaging capacity, presenting an intelligent platinum(IV) prodrug-loaded nanovehicle for UCL-guided dual-stimuli-responsive combination therapy.

Platinum(IV) Prodrugs Incorporating an Indole-Based Derivative, 5-Benzyloxyindole-3-Acetic Acid in the Axial Position Exhibit Prominent Anticancer Activity

Kinetically inert platinum(IV) complexes are a chemical strategy to overcome the impediments of standard platinum(II) antineoplastic drugs like cisplatin, oxaliplatin and carboplatin. In this study, we reported the syntheses and structural characterisation of three platinum(IV) complexes that incorporate 5-benzyloxyindole-3-acetic acid, a bioactive ligand that integrates an indole pharmacophore. The purity and chemical structures of the resultant complexes, P-5B3A, 5-5B3A and 56-5B3A were confirmed via spectroscopic means. The complexes were evaluated for anticancer activity against multiple human cell lines. All complexes proved to be considerably more active than cisplatin, oxaliplatin and carboplatin in most cell lines tested. Remarkably, 56-5B3A demonstrated the greatest anticancer activity, displaying GI50 values between 1.2 and 150 nM. Enhanced production of reactive oxygen species paired with the decline in mitochondrial activity as well as inhibition of histone deacetylase were also demonstrated by the complexes in HT29 colon cells.

Synthesis and anticancer mechanisms of four novel platinum(II) 4'-substituted-2,2':6',2''-terpyridine complexes

Mitophagy, a selective autophagic process, has emerged as a pathway involved in degrading dysfunctional mitochondria. Herein, new platinum(II)-based chemotherapeutics with mitophagy-targeting properties are proposed. Four novel binuclear anticancer Pt(II) complexes with 4'-substituted-2,2':6',2''-terpyridine derivatives (tpy1-tpy4), i.e., [Pt2(tpy1)(DMSO)2Cl4]·CH3OH (tpy1Pt), [Pt(tpy2)Cl][Pt(DMSO)Cl3]·CH3COCH3 (tpy2Pt), [Pt(tpy3)Cl][Pt(DMSO)Cl3] (tpy3Pt), and [Pt(tpy4)Cl]Cl·CH3OH (tpy4Pt), were designed and prepared. Moreover, their potential antitumor mechanism was studied. Tpy1Pt-tpy4Pt exhibited more selective cytotoxicity against cisplatin-resistant SK-OV-3/DDP (SKO3cisR) cancer cells compared with those against ovarian SK-OV-3 (SKO3) cancer cells and normal HL-7702 liver (H702) cells. This selective cytotoxicity of Tpy1Pt-tpy4Pt was better than that of its ligands (i.e., tpy1-tpy4), the clinical drug cisplatin, and cis-Pt(DMSO)2Cl2. The results of various experiments indicated that tpy1Pt and tpy2Pt kill SKO3cisR cancer cells via a mitophagy pathway, which involves the disruption of the mitophagy-related protein expression, dissipation of the mitochondrial membrane potential, elevation of the [Ca2+] and reactive oxygen species levels, promotion of mitochondrial DNA damage, and reduction in the adenosine triphosphate and mitochondrial respiratory chain levels. Furthermore, in vivo experiments indicated that the dinuclear anticancer Pt(II) coordination compound (tpy1Pt) has remarkable therapeutic efficiency (ca. 52.4%) and almost no toxicity. Therefore, the new 4'-substituted-2,2':6',2''-terpyridine Pt(II) coordination compound (tpy1Pt) is a potential candidate for next-generation mitophagy-targeting dinuclear Pt(II)-based anticancer drugs.

Novel Biotinylated Cu(II)-Phenanthroline Complexes: 2D and 3D Cytotoxic Activity and Mechanistic Insight

The interest in the use of copper as a metal scaffold for the development of novel chemotherapeutics has considerably grown in recent years. This is mainly due to the relatively lower toxicity of copper complexes with respect to platinum drugs (i.e., cisplatin), the different mechanisms of action, and the cheaper cost. In the last decades, hundreds of copper-based complexes were developed and screened as anticancer agents, with the antesignanus of all compounds being copper bis-phenanthroline [Cu(phen)₂]²⁺ developed by D.S. Sigman in the late 1990s. In particular, copper(phen) derivatives have been shown high interest in their capacity to interact with DNA by nucleobase intercalation. Here, we report the synthesis and chemical characterization of four novel copper(II) complexes functionalised with phenanthroline derivatives containing biotin. Biotin, also known as Vitamin B7, is involved in a series of metabolic processes, and its receptors are often overexpressed in many tumour cells. A detailed biological analysis including cytotoxicity in 2D and 3D, cellular drug uptake, DNA interaction, and morphological studies are discussed.

Platinum(II) 5-substituted-8-hydroxyquinoline coordination compounds induces mitophagy-mediated apoptosis in A549/DDP cancer cells

For the first time, two new mononuclear platinum(II) coordination compounds, [Pt(L1)(DMSO)Cl] (PtL1) and [Pt(L2)(DMSO)Cl] (PtL2) with the 5-(ethoxymethyl)-8-hydroxyquinoline hydrochloride (H-L1) and 5-bromo-8-hydroxyquinoline (H-L2) have been synthesized and characterized. The cytotoxic activity of PtL1 and PtL2 were screened in both healthy HL-7702 cell line and cancer cell lines, human lung adenocarcinoma A549 cancer cells and cisplatin-resistant lung adenocarcinoma A549/DDP cancer cells (A549R), and were compared to that of the H-L1, H-L2, H-L3 ligands and 8-hydroxyquinoline (H-L3) platinum(II) complex [Pt(L3)(DMSO)Cl] (PtL3). MTT results showed that PtL1 bearing one deprotonated L1 ligand against A549R was more potent by 8.8-48.6 fold than that of PtL2 and PtL3 complexes but was more selective toward healthy HL-7702 cells. In addition, PtL1 and PtL3 overcomes tumour drug resistance by significantly inducing mitophagy and causing the change of the related proteins expression, which leads to cell apoptosis. Moreover, the inhibitory effect of PtL1 on A549 xenograft tumour was 68.2%, which was much higher than that of cisplatin (cisPt, ca. 50.0%), without significantly changing nude mice weight in comparison with the untreated group. This study helps to explore the potential of the platinum(II) 5-substituted-8-hydroxyquinoline coordination compounds for the new Pt-resistant cancer therapy.

Influence of the Fatty Acid Metabolism on the Mode of Action of a Cisplatin(IV) Complex with Phenylbutyrate as Axial Ligands

For a variety of cancer types, platinum compounds are still among the best treatment options. However, their application is limited by side effects and drug resistance. Consequently, multi-targeted platinum(IV) prodrugs that target specific traits of the malignant tissue are interesting new candidates. Recently, cisPt(PhB)₂ was synthesized which, upon reduction in the malignant tissue, releases phenylbutyrate (PhB), a metabolically active fatty acid analog, in addition to cisplatin. In this study, we in-depth investigated the anticancer properties of this new complex in cell culture and in mouse allograft experiments. CisPt(PhB)₂ showed a distinctly improved anticancer activity compared to cisplatin as well as to PhB alone and was able to overcome various frequently occurring drug resistance mechanisms. Furthermore, we observed that differences in the cellular fatty acid metabolism and mitochondrial activity distinctly impacted the drug's mode of action. Subsequent analyses revealed that "Warburg-like" cells, which are characterized by deficient mitochondrial function and fatty acid catabolism, are less capable of coping with cisPt(PhB)₂ leading to rapid induction of a non-apoptotic form of cell death. Summarizing, cisPt(PhB)₂ is a new orally applicable platinum(IV) prodrug with promising activity especially against cisplatin-resistant cancer cells with "Warburg-like" properties.

Synthesis, characterization and biological evaluation of two cyclometalated iridium(III) complexes containing a glutathione S-transferase inhibitor

The cyclometalated iridium(III) compounds have been intensively studied for health-related applications due to their outstanding luminescent properties and multiple anticancer modes of action. Herein, two iridium(III) compounds Ir-1 and Ir-3 containing glutathione S-transferase inhibitor (GSTi) were developed and studied together with two unfunctionalized compounds Ir-2 and Ir-4 as a comparison. Biological study indicated that GSTi-bearing complexes Ir-1 and Ir-3 exert a synergistic effect on the inhibition of cancer cells. The photophysical properties of Ir-1 ∼ Ir-4 were investigated by UV/vis absorption and fluorescence spectroscopy and rationalized with TD-DFT calculations. As expected, GSTi-bearing complexes Ir-1 and Ir-3 exhibited considerable cytotoxicity against both A549 and cisplatin-resistant A549/cis cancer cells, much higher than the unfunctionalized iridium compounds Ir-2 and Ir-4. Further study indicated that Ir-1 and Ir-3 mainly localize in the mitochondria of tumor cells, and exert their cytotoxicity via generating ROS and inhibiting GST activity. The flow cytometry investigations demonstrated that Ir-1 and Ir-3 can arrest the cell cycle in S phase and induce the cell death through apoptosis process. Overall, the complexation of GST inhibitors with cyclometalated iridium(III) agents provides an effective way for potentiating the cytotoxicity of iridium(III) anticancer agents and resensitizing the efficacy against cisplatin resistant cancer cells.

Medicinal inorganic chemistry - challenges, opportunities and guidelines to develop the next generation of radioactive, photoactivated and active site inhibiting metal-based medicines

Medicinal inorganic chemistry is a burgeoning subfield of medicinal chemistry that focuses on the development of metal-based diagnostic and therapeutic agents. This tutorial review aims to provide an introductory primer, present a timely overview of recent discoveries and identify current challenges and opportunities of the field. Three specific areas of discovery are highlighted herein. The first part focuses on metal-based radiopharmaceuticals for diagnostic and therapeutic purposes and specific design criteria for the development of radiopharmaceuticals that combine fundamental aqueous coordination chemistry with elucidation of pharmacokinetics. The second part describes approaches to photodynamic therapy with metal complexes. Here, photophysical characterization, combined with the challenge of careful control of the chemical behavior and selective biological deposition of transition metals with significant off-target toxicity, is discussed. In the third part, we summarize emerging strategies to modulate enzyme inhibition with coordination chemistry, while also highlighting the utility of the unique properties of metal ions for the characterization of mechanisms of action of these emerging diagnostic and therapeutic agents.

DNA Conformational Changes Induced by Its Interaction with Binuclear Platinum Complexes in Solution Indicate the Molecular Mechanism of Platinum Binding

Platinum anticancer drugs inhibit the division of cancer cells through a DNA binding mechanism. The bimetallic platinum compounds have a possibility for blocking DNA replication via the cross-linking of DNA functional groups at different distances. Many compounds with metals of the platinum group have been tested for possible antitumor activity. The main target of their biological action is a DNA molecule. A combined approach to the study of the interaction of DNA with biologically active compounds of this type is proposed. The capabilities of various methods (hydrodynamic, spectral, microscopy) in obtaining information on the type of binding of coordination compounds to DNA are compared. The analysis of DNA binding with platinum binuclear compounds containing pyrazine, tetrazole, 5- methyltetrazole, 3-propanediamine as bridging ligands in a solution was carried out with the methods of circular dichroism (CD), luminescent spectroscopy (LS), low gradient viscometry (LGV), flow birefringence (FB) and atomic force microscopy (AFM). The competitive binding of different platinum compounds to DNA and the analysis of platinum attachment to DNA after protonation of its nitrogen bases simply indicates the involvement of N7 guanine in binding. Fluorescent dye DAPI was also used to recognize the location of platinum compounds in DNA grooves. DNA conformational changes recorded by variations in persistent length, polyelectrolyte swelling, DNA secondary structure, and its stability clarify the molecular mechanism of the biological activity of platinum compounds.