Platinum-Based Combination Therapy: Molecular Rationale, Current Clinical Uses, and Future Perspectives

Inhibition of Chk1 stimulates cytotoxic action of platinum-based drugs and TRAIL combination in human prostate cancer cells

Checkpoint kinase 1 (Chk1) plays an important role in regulation of the cell cycle, DNA damage response and cell death, and represents an attractive target in anticancer therapy. Small-molecule inhibitors of Chk1 have been intensively investigated either as single agents or in combination with various chemotherapeutic drugs and they can enhance the chemosensitivity of numerous tumor types. Here we newly demonstrate that pharmacological inhibition of Chk1 using potent and selective inhibitor SCH900776, currently profiled in phase II clinical trials, significantly enhances cytotoxic effects of the combination of platinum-based drugs (cisplatin or LA-12) and TRAIL (tumor necrosis factor-related apoptosis inducing ligand) in human prostate cancer cells. The specific role of Chk1 in the drug combination-induced cytotoxicity was confirmed by siRNA-mediated silencing of this kinase. Using RNAi-based methods we also showed the importance of Bak-dependent mitochondrial apoptotic pathway in the combined anticancer action of SCH900776, cisplatin and TRAIL. The triple drug combination-induced cytotoxicity was partially enhanced by siRNA-mediated Mcl-1 silencing. Our findings suggest that targeting Chk1 may be used as an efficient strategy for sensitization of prostate cancer cells to killing action of platinum-based chemotherapeutic drugs and TRAIL.

Genetic influence of meningioma on cisplatin resistance: a Mendelian randomization analysis

BACKGROUND

Although various aspects of cisplatin resistance have been studied, the impact of genetic variations still needs to be explored.

AIM

This study aimed to investigate the impact of cisplatin on meningiomas using a two-sample Mendelian randomization (MR) approach, employing genetic variants associated with cisplatin use as instrumental variables.

METHOD

We conducted a two-sample MR analysis using genome-wide association study (GWAS) data. Instrumental variables were derived from single-nucleotide polymorphisms (SNPs) associated with meningioma to estimate the causal relationship with cisplatin resistance. Sensitivity analyses were performed to confirm the findings.

RESULTS

Genetic predisposition to meningioma significantly increased the risk of cisplatin resistance (odds ratio (OR): 1.63; 95% confidence interval (CI) 1.44-1.85, P < 0.05). Sensitivity analyses supported the causal link.

CONCLUSION

This MR study suggests that genetic predisposition to meningioma increases susceptibility to cisplatin resistance. Further research is needed to uncover the mechanisms behind these causal effects.

Discovery of Novel p53-MDM2 Inhibitor (RG7388)-Conjugated PlatinumIV Complexes as Potent Antitumor Agents

While a number of p53-MDM2 inhibitors have progressed into clinical trials for the treatment of cancer, their progression has been hampered by a variety of problems, including acquired drug resistance, dose-dependent toxicity, and limited clinical efficiency. To make more progress, we integrated the advantages of MDM2 inhibitors and platinum drugs to construct novel PtIV-RG7388 (a selective MDM2 inhibitor) complexes. Most complexes, especially 5a and 5b, displayed greatly improved antiproliferative activity against both wild-type and mutated p53 cancer cells. Remarkably, 5a exhibited potent in vivo tumor growth inhibition in the A549 xenograft model (66.5%) without apparent toxicity. It arrested the cell cycle at both the S phase and the G2/M phase and efficiently induced apoptosis via the synergistic effects of RG7388 and cisplatin. Altogether, PtIV-RG7388 complex 5a exhibited excellent in vitro and in vivo antitumor activities, highlighting the therapeutic potential of PtIV-RG7388 complexes as antitumor agents.

Cisplatin in the era of PARP inhibitors and immunotherapy

Platinum compounds such as cisplatin, carboplatin and oxaliplatin are widely used in chemotherapy. Cisplatin induces cytotoxic DNA damage that blocks DNA replication and gene transcription, leading to arrest of cell proliferation. Although platinum therapy alone is effective against many tumors, cancer cells can adapt to the treatment and gain resistance. The mechanisms for cisplatin resistance are complex, including low DNA damage formation, high DNA repair capacity, changes in apoptosis signaling pathways, rewired cell metabolisms, and others. Drug resistance compromises the clinical efficacy and calls for new strategies by combining cisplatin with other therapies. Exciting progress in cancer treatment, particularly development of poly (ADP-ribose) polymerase (PARP) inhibitors and immune checkpoint inhibitors, opened a new chapter to combine cisplatin with these new cancer therapies. In this Review, we discuss how platinum synergizes with PARP inhibitors and immunotherapy to bring new hope to cancer patients.

Kinetically Inert Platinum (II) Complexes for Improving Anticancer Therapy: Recent Developments and Road Ahead

The search for better chemotherapeutic drugs to alleviate the deficiencies of existing platinum (Pt) drugs has picked up the pace in the millennium. There has been a disparate effort to design better and safer Pt drugs to deal with the problems of deactivation, Pt resistance and toxic side effects of clinical Pt drugs. In this review, we have discussed the potential of kinetically inert Pt complexes as an emerging class of next-generation Pt drugs. The introduction gives an overview about the development, use, mechanism of action and side effects of clinical Pt drugs as well as the various approaches to improve some of their pharmacological properties. We then describe the impact of kinetic lability on the pharmacology of functional Pt drugs including deactivation, antitumor efficacy, toxicity and resistance. Following a brief overview of numerous pharmacological advantages that a non-functional kinetically inert Pt complex can offer; we discussed structurally different classes of kinetically inert Pt (II) complexes highlighting their unique pharmacological features.

Platinum-based drugs and hydrogel: a promising anti-tumor combination

Platinum-based drugs are widely used as first-line anti-tumor chemotherapy agents. However, they also have nonnegligible side effects due to the free drugs in circulation. Therefore, it is necessary to develop efficient and safe delivery systems for better tumor cell targeting. Hydrogel is a promising anti-tumor drug carrier that can form a platinum/hydrogel combination system for drug release, which has shown better anti-tumor effects in some studies. However, there is a lack of systematic summary in this field. This review aims to provide a comprehensive overview of the platinum/hydrogel combination system with the following sections: firstly, an introduction of platinum-based drugs; secondly, an analysis of the platinum/hydrogel combination system; and thirdly, a discussion of the advantages of the hydrogel-based delivery system. We hope this review can offer some insights for the development of the platinum/hydrogel combination system for better cancer therapy.

5-Nitrofuryl-Containing Thiosemicarbazone Gold(I) Compounds: Synthesis, Stability Studies, and Anticancer Activity

This work describes the synthesis of four gold(I) [AuClL] compounds containing chloro and biologically active protonated thiosemicarbazones based on 5-nitrofuryl (L=HSTC). The stability of the compounds in dichloromethane, DMSO, and DMSO/culture media solutions was investigated by spectroscopy, cyclic voltammetry, and conductimetry, indicating the formation overtime of cationic monometallic [Au(HTSC)(DMSO)]± or [Au(HTSC)2 ]± , and/or dimeric species. Neutral [{Au(TSC)}2 ] species were obtained from one of the compounds in dichlomethane/n-hexane solution and characterized by X-ray crystallography revealing a Au-Au bond, and deprotonated thiosemicarbazone (TSC). The cytotoxicity of the gold compounds and thiosemicarbazone ligands was evaluated against selected cancer cell lines and compared to that of Auranofin. Studies of the most stable, cytotoxic, and selective compound on a renal cancer cell line (Caki-1) demonstrated its relevant antimigratory and anti-angiogenic properties, and preferential accumulation in the cell nuclei. Its mode of action seems to involve interaction with DNA, and subsequent cell death via apoptosis.

A Dual Stimuli-Responsive Nanoplatform Loaded PtIV -Triptolide Prodrug for Achieving Synergistic Therapy toward Breast Cancer

To strengthen the antitumor efficacy and avoid toxicity to normal cells of cisplatin and triptolide, herein, an acid and glutathione (GSH) dual-controlled nanoplatform for enhanced cancer treatment through the synergy of both "1+1" apoptosis and "1+1" ferroptosis is designed. Remarkably, ZIF8 in response to tumor microenvironment enhances drug targeting and protects drugs from premature degradation. Meanwhile, the PtIV  center can be easily reduced to cisplatin because of the large amount of GSH, thus liberating the triptolide as the coordinated ligand. The released cisplatin and hemin in turn boost the tumor cell "1+1" apoptosis through chemotherapy and photodynamic therapy, respectively. Furthermore, GSH reduction through PtIV  weakens the activation of glutathione peroxidase 4 (GPX4) effectively. The released triptolide can inhibit the expressions of GSH by regulating nuclear factor E2 related factor 2 (Nrf2), further promoting membrane lipid peroxidation, thus "1+1" ferroptosis can be achieved. Both in vitro and in vivo results demonstrate that the nanosystem can not only perform superior specificity and therapeutic outcomes but also reduce the toxicity to normal cells/tissues of cisplatin and triptolide effectively. Overall, the prodrug-based smart system provides an efficient therapeutic strategy for cancer treatment by virtue of the effect of enhanced "1+1" apoptosis and "1+1" ferroptosis therapies.

Synthesis, Structural Characterization, Cytotoxicity, and Protein/DNA Binding Properties of Pyridoxylidene-Aminoguanidine-Metal (Fe, Co, Zn, Cu) Complexes

Pyridoxylidene-aminoguanidine (PLAG) and its transition metal complexes are biologically active compounds with interesting properties. In this contribution, three new metal-PLAG complexes, Zn(PLAG)(SO4)(H2O)].∙H2O (Zn-PLAG), [Co(PLAG)2]SO4∙2H2O (Co-PLAG), and [Fe(PLAG)2]SO4∙2H2O) (Fe-PLAG), were synthetized and characterized by the X-ray crystallography. The intermolecular interactions governing the stability of crystal structure were compared to those of Cu(PLAG)(NCS)2 (Cu-PLAG) within Hirshfeld surface analysis. The structures were optimized at B3LYP/6-31+G(d,p)(H,C,N,O,S)/LanL2DZ (Fe,Co,Zn,Cu), and stability was assessed through Natural Bond Orbital Theory and Quantum Theory of Atoms in Molecules. Special emphasis was put on investigating the ligand's stability and reactivity. The binding of these compounds to Bovine and Human serum albumin was investigated by spectrofluorometric titration. The importance of complex geometry and various ligands for protein binding was shown. These results were complemented by the molecular docking study to elucidate the most important interactions. The thermodynamic parameters of the binding process were determined. The binding to DNA, as one of the main pathways in the cell death cycle, was analyzed by molecular docking. The cytotoxicity was determined towards HCT116, A375, MCF-7, and A2780 cell lines. The most active compound was Cu-PLAG due to the presence of PLAG and two thiocyanate ligands.

A new family of luminescent [Pt(pbt)2(C6F5)L]n+ (n = 1, 0) complexes: synthesis, optical and cytotoxic studies

Given the widely recognized bioactivity of 2-arylbenzothiazoles against tumor cells, we have designed a new family of luminescent heteroleptic pentafluorophenyl-bis(2-phenylbenzothiazolyl) PtIV derivatives, fac-[Pt(pbt)2(C6F5)L]n+ (n = 1, 0) [L = 4-Mepy 1, 4-pyridylbenzothiazole (pybt) 2, 4,4'-bipyridine (4,4'-bpy) 3, 1,2-bis-(4-pyridyl)ethylene (bpe) 4 (E/Z ratio: 90/10), 1,4-bis-(pyridyl)butadiyne (bpyb) 5, trifluoroacetate (-OCOCF3) 6] and a dinuclear complex [{Pt(pbt)2(C6F5)}2(μ-bpyb)](PF6)27, in which the trans ligand to the metalated C-(pbt) was varied to modify the optical properties and lipophilicity. Their photophysical properties were systematically studied through experimental and theoretical investigations, which were strongly dependent on the identity of the N-bonded ligand. Thus, complexes 1, 3 and 6 display, in different media, emission from the triplet excited states of primarily intraligand 3ILCT nature localized on the pbt ligand, while the emissions of 2, 5 and 7 were ascribed to a mixture of close 3IL'(N donor)/3ILCT(pbt) excited states, as supported by lifetime measurements and theoretical calculations. Irradiation of the initial E/Z mixture of 4 (15 min) led to a steady state composed of roughly 1 : 1.15 (E : Z) and this complex was not emissive at room temperature due to an enhanced intramolecular E to Z isomerization process of the 1,2-bis-(4-pyridyl)ethylene ligand. Complexes 1-3 and 6 showed excellent quantum yields for the generation of singlet oxygen in aerated MeCN solution with the values of ϕ(1O2) ranging from 0.66 to 0.86 using phenalenone as a reference. Cationic complexes 1-3 exhibited remarkable efficacy in the nanomolar range against A549 (lung carcinoma) and HeLa (cervix carcinoma) cell lines with notable selectivity relative to the non-tumorigenic BEAS-2B (bronchial epithelium) cells. In the A549 cell line, the neutral complex 6 showed low cytotoxicity (IC50: 29.40 μM) and high photocytotoxicity (IC50: 5.75) when cells were irradiated with blue light for 15 min. These complexes do not show evidence of DNA interaction.

Recent Advances of Platinum-Based Anticancer Complexes in Combinational Multimodal Therapy

Platinum drugs with manifest therapeutic effects are widely used, but their systemic toxicity and the drug resistance acquired by cancer cells limit their clinical applications. Thus, the exploration on appropriate methods and strategies to overcome the limitations of traditional platinum drugs becomes extremely necessary. Combination therapy of platinum drugs can inhibit tumor growth and metastasis in an additive or synergistic manner, and can potentially reduce the systemic toxicity of platinum drugs and overcome platinum-resistance. This review summarizes the various modalities and current progress in platinum-based combination therapy. The synthetic strategies and therapeutic effects of some platinum-based anticancer complexes in the combination of platinum drugs with gene editing, ROS-based therapy, thermal therapy, immunotherapy, biological modelling, photoactivation, supramolecular self-assembly and imaging modality are briefly described. Their potential challenges and prospects are also discussed. It is hoped that this review will inspire researchers to have more ideas for the future development of highly effective platinum-based anti-cancer complexes.

Emerging platinum(IV) prodrug nanotherapeutics: A new epoch for platinum-based cancer therapy

Owing to the unique DNA damaging cytotoxicity, platinum (Pt)-based chemotherapy has long been the first-line choice for clinical oncology. Unfortunately, Pt drugs are restricted by the severe dose-dependent toxicity and drug resistance. Correspondingly, Pt(IV) prodrugs are developed with the aim to improve the antitumor performance of Pt drugs. However, as "free" molecules, Pt(IV) prodrugs are still subject to unsatisfactory in vivo destiny and antitumor efficacy. Recently, Pt(IV) prodrug nanotherapeutics, inheriting both the merits of Pt(IV) prodrugs and nanotherapeutics, have emerged and demonstrated the promise to address the underexploited dilemma of Pt-based cancer therapy. Herein, we summarize the latest fronts of emerging Pt(IV) prodrug nanotherapeutics. First, the basic outlines of Pt(IV) prodrug nanotherapeutics are overviewed. Afterwards, how versatile Pt(IV) prodrug nanotherapeutics overcome the multiple biological barriers of antitumor drug delivery is introduced in detail. Moreover, advanced combination therapies based on multimodal Pt(IV) prodrug nanotherapeutics are discussed with special emphasis on the synergistic mechanisms. Finally, prospects and challenges of Pt(IV) prodrug nanotherapeutics for future clinical translation are spotlighted.

The Effect of Metal Ions (Fe, Co, Ni, and Cu) on the Molecular-Structural, Protein Binding, and Cytotoxic Properties of Metal Pyridoxal-Thiosemicarbazone Complexes

Thiosemicarbazones and their transition metal complexes are biologically active compounds and anticancer agents with versatile structural properties. In this contribution, the structural features and stability of four pyridoxal-thiosemicarbazone (PLTSC) complexes with Fe, Co, Ni, and Cu were investigated using the density functional theory and natural bond orbital approach. Special emphasis was placed on the analysis of the donor atom-metal interactions. The geometry of compounds and crystallographic structures were further examined by Hirshfeld surface analysis, and the main intermolecular interactions were outlined. It has been shown that the geometry and the number of PLTSC units in the structure determine the type and contribution of the specific interactions. The binding of all four complexes to bovine and human serum albumin was investigated through spectrofluorometric titration. The dependency of the thermodynamic parameters on the present metal ion and geometry was explained by the possible interactions through molecular docking simulations. The binding of complexes to DNA, as one of the possible ways the compounds could induce cell death, was examined by molecular docking. The cytotoxicity was measured towards HCT116, A375, MCF-7, A2780, and MCF5 cell lines, with Cu-PLTSC being the most active, as it had the highest affinity towards DNA and proteins.

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.

Review of genetic and pharmacogenetic differences in cytotoxic and targeted therapies for pancreatic cancer in African Americans

Pancreatic ductal adenocarcinoma (PDAC) is currently the third leading cause of cancer mortality and the incidence is projected to increase by 2030. Despite recent advances in its treatment, African Americans have a 50-60% higher incidence and 30% higher mortality rate when compared to European Americans possibly resulting from differences in socioeconomic status, access to healthcare, and genetics. Genetics plays a role in cancer predisposition, response to cancer therapeutics (pharmacogenetics), and in tumor behavior, making some genes targets for oncologic therapeutics. We hypothesize that the germline genetic differences in predisposition, drug response, and targeted therapies also impact PDAC disparities. To demonstrate the impact of genetics and pharmacogenetics on PDAC disparities, a review of the literature was performed using PubMed with variations of the following keywords: pharmacogenetics, pancreatic cancer, race, ethnicity, African, Black, toxicity, and the FDA-approved drug names: Fluoropyrimidines, Topoisomerase inhibitors, Gemcitabine, Nab-Paclitaxel, Platinum agents, Pembrolizumab, PARP-inhibitors, and NTRK fusion inhibitors. Our findings suggest that the genetic profiles of African Americans may contribute to disparities related to FDA approved chemotherapeutic response for patients with PDAC. We recommend a strong focus on improving genetic testing and participation in biobank sample donations for African Americans. In this way, we can improve our current understanding of genes that influence drug response for patients with PDAC.

Half-Sandwich Type Platinum-Group Metal Complexes of C-Glucosaminyl Azines: Synthesis and Antineoplastic and Antimicrobial Activities

While platinum-based compounds such as cisplatin form the backbone of chemotherapy, the use of these compounds is limited by resistance and toxicity, driving the development of novel complexes with cytostatic properties. In this study, we synthesized a set of half-sandwich complexes of platinum-group metal ions (Ru(II), Os(II), Ir(III) and Rh(III)) with an N,N-bidentate ligand comprising a C-glucosaminyl group and a heterocycle, such as pyridine, pyridazine, pyrimidine, pyrazine or quinoline. The sugar-containing ligands themselves are unknown compounds and were obtained by nucleophilic additions of lithiated heterocycles to O-perbenzylated 2-nitro-glucal. Reduction of the adducts and, where necessary, subsequent protecting group manipulations furnished the above C-glucosaminyl heterocycles in their O-perbenzylated, O-perbenzoylated and O-unprotected forms. The derived complexes were tested on A2780 ovarian cancer cells. Pyridine, pyrazine and pyridazine-containing complexes proved to be cytostatic and cytotoxic on A2780 cells, while pyrimidine and quinoline derivatives were inactive. The best complexes contained pyridine as the heterocycle. The metal ion with polyhapto arene/arenyl moiety also impacted on the biological activity of the complexes. Ruthenium complexes with p-cymene and iridium complexes with Cp* had the best performance in ovarian cancer cells, followed by osmium complexes with p-cymene and rhodium complexes with Cp*. Finally, the chemical nature of the protective groups on the hydroxyl groups of the carbohydrate moiety were also key determinants of bioactivity; in particular, O-benzyl groups were superior to O-benzoyl groups. The IC50 values of the complexes were in the low micromolar range, and, importantly, the complexes were less active against primary, untransformed human dermal fibroblasts; however, the anticipated therapeutic window is narrow. The bioactive complexes exerted cytostasis on a set of carcinomas such as cell models of glioblastoma, as well as breast and pancreatic cancers. Furthermore, the same complexes exhibited bacteriostatic properties against multiresistant Gram-positive Staphylococcus aureus and Enterococcus clinical isolates in the low micromolar range.

Modulation of the Cytotoxic Properties of Pd(II) Complexes Based on Functionalized Carboxamides Featuring Labile Phosphoryl Coordination Sites

Platinum-based drugs are commonly recognized as a keystone in modern cancer chemotherapy. However, intrinsic and acquired resistance as well as serious side effects often caused by the traditional Pt(II) anticancer agents prompt a continuous search for more selective and efficient alternatives. Today, significant attention is paid to the compounds of other transition metals, in particular those of palladium. Recently, our research group has suggested functionalized carboxamides as a useful platform for the creation of cytotoxic Pd(II) pincer complexes. In this work, a robust picolinyl- or quinoline-carboxamide core was combined with a phosphoryl ancillary donor group to achieve hemilabile coordination capable of providing the required level of thermodynamic stability and kinetic lability of the ensuing Pd(II) complexes. Several cyclopalladated derivatives featuring either a bi- or tridentate pincer-type coordination mode of the deprotonated phosphoryl-functionalized amides were selectively synthesized and fully characterized using IR and NMR spectroscopy as well as X-ray crystallography. The preliminary evaluation of the anticancer potential of the resulting palladocycles revealed a strong dependence of their cytotoxic properties on the binding mode of the deprotonated amide ligands and demonstrated certain advantages of the pincer-type ligation.

Elucidating the Multimodal Anticancer Mechanism of an Organometallic Terpyridine Platinum(II) N-Heterocyclic Carbene Complex against Triple-Negative Breast Cancer In Vitro and In Vivo

Treatment of triple-negative breast cancer (TNBC) has long been a medical challenge because of the lack of effective therapeutic targets. Targeting lipid, carbohydrate, and nucleotide metabolism pathways has recently been proven as a promising option in view of three heterogeneous metabolic-pathway-based TNBC subtypes. Here, we present a multimodal anticancer platinum(II) complex, named Pt(II)caffeine, with a novel mode of action involving simultaneous mitochondrial damage, inhibition of lipid, carbohydrate, and nucleotide metabolic pathways, and promotion of autophagy. All these biological processes eventually result in a strong suppression of TNBC MDA-MB-231 cell proliferation both in vitro and in vivo. The results indicate that Pt(II)caffeine, influencing cellular metabolism at multiple levels, is a metallodrug with increased potential to overcome the metabolic heterogeneity of TNBC.

Association of variations in the CAT and prognosis in lung cancer patients with platinum-based chemotherapy

PURPOSE: To explore the relationship between ATM, ATR and CAT polymorphisms and prognosis of lung cancer patients received platinum-based chemotherapy.

METHODS: 404 patients with lung cancer who received platinum-chemotherapy were enrolled and DNA typing was performed. Cox regression analysis and stratification analyses was performed to assess relationships between OS and PFS with SNPs genotypes. The prognosis of lung adenocarcinomaand squamous cell carcinomapatients was analyzed with The Cancer Genome Atlas (TCGA) database according to the grouping of CAT expression.

RESULTS:CAT rs769217 was significantly related to PFS of patients with lung cancer who received platinum-chemotherapy. In the Additive model, rs769217 was associated with PFS (HR = 0.747, 95% CI = 0.581–0.960, p = 0.023). In the Dominant model, CT and TT genotypes led to lung cancer progression 0.738 times more than CC genotype. In stratification analyses of association between CAT rs769217 polymorphisms and PFS, the HR of patients at stage IV in additive model was 0.73, and HR was 0.745 (p = 0.034) in dominant model. For OS analyses, HR was 0.672 in the older lung cancer patients (&gt;55 years old) in additive model. Meanwhile, in the Dominant model, it was found that the older patients with CT and TT genotypes had better prognosis, and the risk of death after receiving platinum-based chemotherapy was 0.692 times that of patients with CC genotype (p = 0.037). TCGA data shows that LUAD patients with high CAT expression have longer OS (p = 0.020).

CONCLUSION:CAT rs769217 is significantly related to PSF of platinum-based chemotherapy in lung cancer patients and may be a biomarker for predicting the prognosis of lung cancer patients with platinum-based chemotherapy.

USP35 promotes cell proliferation and chemotherapeutic resistance through stabilizing FUCA1 in colorectal cancer

Ubiquitin-specific-processing proteases 35 (USP35) is an under-characterized deubiquitinase and its role in colorectal cancer (CRC) remains unclear. Here, we focus on delineating the impact of USP35 on CRC cell proliferation and chemo-resistance, as well as the possible regulatory mechanism. By examining the genomic database and clinical samples, we found that USP35 was overexpressed in CRC. Further functional studies showed that enhanced USP35 expression promoted CRC cell proliferation and resistance to oxaliplatin (OXA) and 5-fluorouracil (5-FU), whereas USP35 depletion impeded cell proliferation and sensitized cells to OXA and 5-FU treatments. Then, to explore the possible mechanism underlying USP35-triggered cellular responses, we performed co-immunoprecipitation (co-IP) followed by mass spectrometry (MS) analysis and identified α-L-fucosidase 1 (FUCA1) as a direct deubiquitiation target of USP35. Importantly, we demonstrated that FUCA1 was an essential mediator for USP35-induced cell proliferation and chemo-resistance in vitro and in vivo. Finally, we observed that nucleotide excision repair (NER) components (e.g., XPC, XPA, ERCC1) were up-regulated by USP35-FUCA1 axis, indicating a potential mechanism for USP35-FUCA1-mediated platinum resistance in CRC. Together, our results for the first time explored the role and important mechanism of USP35 in CRC cell proliferation and chemotherapeutic response, providing a rationale for USP35-FUCA1-targeted therapy in CRC.

Half sandwich-type osmium, ruthenium, iridium and rhodium complexes with bidentate glycosyl heterocyclic ligands induce cytostasis in platinum-resistant ovarian cancer cells and bacteriostasis in Gram-positive multiresistant bacteria

The toxicity of and resistance to platinum complexes as cisplatin, oxaliplatin or carboplatin calls for the replacement of these therapeutic agents in clinical settings. We have previously identified a set of half sandwich-type osmium, ruthenium and iridium complexes with bidentate glycosyl heterocyclic ligands exerting specific cytostatic activity on cancer cells but not on non-transformed primary cells. The apolar nature of the complexes, conferred by large, apolar benzoyl protective groups on the hydroxyl groups of the carbohydrate moiety, was the main molecular feature to induce cytostasis. We exchanged the benzoyl protective groups to straight chain alkanoyl groups with varying length (3 to 7 carbon units) that increased the IC₅₀ value as compared to the benzoyl-protected complexes and rendered the complexes toxic. These results suggest a need for aromatic groups in the molecule. The pyridine moiety of the bidentate ligand was exchanged for a quinoline group to enlarge the apolar surface of the molecule. This modification decreased the IC₅₀ value of the complexes. The complexes containing [(η⁶-p-cymene)Ru(II)], [(η⁶-p-cymene)Os(II)] or [(η⁵-Cp*)Ir(III)] were biologically active unlike the complex containing [(η⁵-Cp*)Rh(III)]. The complexes with cytostatic activity were active on ovarian cancer (A2780, ID8), pancreatic adenocarcinoma (Capan2), sarcoma (Saos) and lymphoma cell lines (L428), but not on primary dermal fibroblasts and their activity was dependent on reactive oxygen species production. Importantly, these complexes were cytostatic on cisplatin-resistant A2780 ovarian cancer cells with similar IC₅₀ values as on cisplatin-sensitive A2780 cells. In addition, the quinoline-containing Ru and Os complexes and the short chain alkanoyl-modified complexes (C3 and C4) proved to be bacteriostatic in multiresistant Gram-positive Enterococcus and Staphylococcus aureus isolates. Hereby, we identified a set of complexes with submicromolar to low micromolar inhibitory constants against a wide range of cancer cells, including platinum resistant cells and against multiresistant Gram-positive bacteria.

Developing a Gallium(III) Agent Based on the Properties of the Tumor Microenvironment and Lactoferrin: Achieving Two-Agent Co-delivery and Multi-targeted Combination Therapy of Cancer

To develop a next-generation anticancer metal-based drug, realize the multi-targeted combination therapy of protein drug and metal-based drug for cancer, solve their co-delivery challenges, and improve their in vivo targeting ability, we proposed to develop a multi-targeted anticancer metal-based agent exploiting the properties of the tumor microenvironment (TME) and of lactoferrin (LF). To this end, we optimized a series of gallium (Ga, III) isopropyl-2-pyridyl-ketone thiosemicarbazone compounds to obtain a Ga compound (C4) with remarkable cytotoxicity and then constructed a new LF-C4 nanoparticle (LF-C4 NP) delivery system. In vivo studies showed that LF-C4 NPs not only had a greater capacity for inhibiting tumor growth than LF or C4 alone but also solved the co-delivery problems of LF and C4 and improved their targeting ability. Furthermore, free C4 and LF-C4 NPs inhibited tumor growth through multiple synergistic actions on the TME: killing cancer cell, inhibiting tumor angiogenesis, and activating immune system.

A Pt(IV)-conjugated brain penetrant macrocyclic peptide shows pre-clinical efficacy in glioblastoma

Glioblastoma (GBM) is the most aggressive primary malignant brain tumor, with a median survival of approximately 15 months. Treatment is limited by the blood-brain barrier (BBB) which restricts the passage of most drugs to the brain. We previously reported the design and synthesis of a BBB-penetrant macrocyclic cell-penetrating peptide conjugate (M13) covalently linked at the axial position of a Pt(IV) cisplatin prodrug. Here we show the Pt(IV)-M13 conjugate releases active cisplatin upon intracellular reduction and effects potent in vitro GBM cell killing. Pt(IV)-M13 significantly increased platinum uptake in an in vitro BBB spheroid model and intravenous administration of Pt(IV)-M13 in GBM tumor-bearing mice led to higher platinum levels in brain tissue and intratumorally compared with cisplatin. Pt(IV)-M13 administration was tolerated in naïve nude mice at higher dosage regimes than cisplatin and significantly extended survival above controls in a murine GBM xenograft model (median survival 33 days for Pt(IV)-M13 vs 24 days for Pt(IV) prodrug, 22.5 days for cisplatin and 22 days for control). Increased numbers of γH2AX nuclear foci, biomarkers of DNA damage, were observed in tumors of Pt(IV)-M13-treated mice, consistent with elevated platinum levels. The present work provides the first demonstration that systemic injection of a Pt(IV) complex conjugated to a brain-penetrant macrocyclic peptide can lead to increased platinum levels in the brain and extend survival in mouse GBM models, supporting further development of this approach and the utility of brain-penetrating macrocyclic peptide conjugates for delivering non-BBB penetrant drugs to the central nervous system.

Recent advances in combretastatin A-4 codrugs for cancer therapy

CA4 is a potent microtubule polymerization inhibitor and vascular disrupting agent. However, the in vivo efficiency of CA4 is limited owing to its poor pharmacokinetics resulting from its high lipophilicity and low water solubility. To improve the water solubility, CA4 phosphate (CA4P) has been developed and shows potent antivascular and antitumor effects. CA4P had been evaluated as a vascular disrupting agent in previousc linical trials. However, it had been discontinued due to the lack of a meaningful improvement in progression-free survival and unfavorable partial response data. Codrug is a drug design approach to chemically bind two or more drugs to improve therapeutic efficiency or decrease adverse effects. This review describes the progress made over the last twenty years in developing CA4-based codrugs to improve the therapeutic profile and achieve targeted delivery to cancer tissues. It also discusses the existing problems and the developmental prospects of CA4 codrugs.

Repurposing FDA-approved drugs against the toxicity of platinum-based anticancer drugs

Platinum-based anticancer drugs (PADs), mainly cisplatin, carboplatin, and oxaliplatin, are widely used efficacious long-standing anticancer agents for treating several cancer types. However, clinicians worry about PAD chemotherapy and its induction of severe non-targeted organ toxicity. Compelling evidence has shown that toxicity of PAD on delicate body organs is associated with free radical generation, DNA impairment, endocrine and mitochondrial dysfunctions, oxidative inflammation, apoptosis, endoplasmic reticulum stress, and activation of regulator signaling proteins, cell cycle arrest, apoptosis, and pathways. The emerging trend is the repurposing of FDA-approved non-anticancer drugs (FNDs) for combating the side effects toxicity of PADs. Thus, this review chronicled the mechanistic preventive and therapeutic effects of FNDs against PAD organ toxicity in preclinical studies. FNDs are potential clinical drugs for the modulation of toxicity complications associated with PAD chemotherapy. Therefore, FNDs may be suggested as non-natural agent inhibitors of unpalatable side effects of PADs.

The role of Platinum(IV)-based antitumor drugs and the anticancer immune response in medicinal inorganic chemistry. A systematic review from 2017 to 2022

Platinum-based antitumor drugs have been used in many types of tumors due to its broad antitumor spectrum in clinic. Encouraged by the cisplatin's (CDDP) worldwide success in cancer chemotherapy, the research in platinum-based antitumor drugs has evolved from traditional platinum drug to multi-ligand and multifunctional platinum prodrugs over half a century. With the rapid development of metal drugs and the anticancer immune response, challenges and opportunities in platinum drug research have been shifted from traditional platinum-based drugs to platinum-based hybrids and the direction of development is tending toward photodynamic therapy, nano-delivery therapy, drug combination, targeted therapy, diagnostic therapy, immune-combination therapy and tumor stem cell therapy. In this review, we first exhaustively overviewed the role of platinum-based antitumor prodrugs and the anticancer immune response in medicinal inorganic chemistry based on the special nanomaterials, the modification of specific ligands, and the multiple functions obtained that are beneficial for tumor therapy in the last five years. We also categorized them according to drug potency and function. There hasn't been a comprehensive evaluation of precursor platinum drugs in prior articles. And a multifarious approach to distinguish and detail the variety of alterations of platinum-based precursors in various valence states also hasn't been summarized. In addition, this review points out the main problems at the interface of chemistry, biology, and medicine from their action mechanisms for current platinum drug development, and provides up-to-date potential strategies from drug design perspectives to circumvent those drawbacks. And a promising idea is also enlightened for researchers in the development and discovery of platinum prodrugs.

Targeted cancer phototherapy using phthalocyanine-anticancer drug conjugates

Phototherapy, the use of light to selectively ablate cancerous tissue, is a compelling prospect. Phototherapy is divided into two major domains: photodynamic and photothermal, whereby photosensitizer irradiation generates reactive oxygen species or heat, respectively, to disrupt the cancer microenvironment. Phthalocyanines (Pcs) are prominent phototherapeutics due to their desirable optical properties and structural versatility. Targeting of Pc photosensitizers historically relied on the enhanced permeation and retention effect, but the weak specificity engendered by this approach has hindered bench-to-clinic translation. To improve specificity, antibody and peptide active-targeting groups have been employed to some effect. An alternative targeting method exploits the binding of anticancer drugs to direct the photosensitizer close to essential cellular components, allowing for precise, synergistic phototherapy. This Perspective explores the use of Pc-drug conjugates as targeted anticancer phototherapeutic systems with examples of Pc-platin, Pc-kinase, and Pc-anthracycline conjugates discussed in detail.

Design and biological features of platinum (II) complexes with 3-hydroxy-3-(Trifluoromethyl)cyclobutane-1,1-Dicarboxylate as a leaving ligand

A series of platinum compounds 2a-5a and 2b-5b with fluoro-functional groups are designed and synthesized. Among them, complex 2b is the most effective agent with 3-hydroxy-3-(trifluoromethyl)cyclobutane-1,1-dicarboxylate as a leaving ligand, which showed better cytotoxic activity than compounds containing only CF₃ or OH group at 3-position of cyclobutane-1,1-dicarboxylate. The water solubility of 2a is better than that of carboplatin (32 mg/mL vs. 16 mg/mL), and its antitumor activity on A549 is 4.6-fold higher than that of carboplatin. The IC₅₀ value of 2b on A549 cells is 4.73 ± 0.64 μM, which is comparable to that of oxaliplatin and higher than that of carboplatin. Meanwhile, 2a and 2b are less toxic than oxaliplatin and cisplatin toward BEAS-2B cells. Moreover, 2a and 2b induce cell apoptosis in vitro by the Bax-Bcl-2-caspase-3 pathway and ferroptosis through inhibiting GPx-4 and elevating COX2. Results from in vivo experiment show that the inhibition rate of A549 xenograft tumor is cisplatin > 2b > oxaliplatin > 2a > carboplatin.

Combination of microtubule targeting agents with other antineoplastics for cancer treatment

Microtubule targeting agents (MTAs) have attracted extensive attention for cancer treatment. However, their clinical efficacies are limited by intolerable toxicities, inadequate efficacy and acquired multidrug resistance. The combination of MTAs with other antineoplastics has become an efficient strategy to lower the toxicities, overcome resistance and improve the efficacies for cancer treatment. In this article, we review the combinations of MTAs with some other anticancer drugs, such as cytotoxic agents, kinases inhibitors, histone deacetylase inhibitors, immune checkpoints inhibitors, to overcome these obstacles. We strongly believe that this review will provide helpful information for combination therapy based on MTAs.

Genetic Variants in Double-Strand Break Repair Pathway Genes to Predict Platinum-Based Chemotherapy Prognosis in Patients With Lung Cancer

Objective: The purpose of this study was to investigate the associations of genetic variants in double-strand break (DSB) repair pathway genes with prognosis in patients with lung cancer treated with platinum-based chemotherapy.

Methods: Three hundred ninety-nine patients with lung cancer who received platinum-based chemotherapy for at least two cycles were included in this study. A total of 35 single nucleotide polymorphisms (SNPs) in DSB repair, base excision repair (BER), and nucleotide excision repair (NER) repair pathway genes were genotyped, and were used to evaluate the overall survival (OS) and the progression-free survival (PFS) of patients who received platinum-based chemotherapy using Cox proportional hazard models.

Results: The PFS of patients who carried the MAD2L2 rs746218 GG genotype was shorter than that in patients with the AG or AA genotypes (recessive model: p = 0.039, OR = 5.31, 95% CI = 1.09–25.93). Patients with the TT or GT genotypes of TNFRSF1A rs4149570 had shorter OS times than those with the GG genotype (dominant model: p = 0.030, OR = 0.57, 95% CI = 0.34–0.95). We also investigated the influence of age, gender, histology, smoking, stage, and metastasis in association between SNPs and OS or PFS in patients with lung cancer. DNA repair gene SNPs were significantly associated with PFS and OS in the subgroup analyses.

Conclusion: Our study showed that variants in MAD2L2 rs746218 and TNFRSF1A rs4149570 were associated with shorter PFS or OS in patients with lung cancer who received platinum-based chemotherapy. These variants may be novel biomarkers for the prediction of prognosis of patients with lung cancer who receive platinum-based chemotherapy.

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

Despite the wide clinical use of platinum drugs in cancer treatment, their severe side effects and lack of tumor selectivity seriously limit their further clinical application. To address the limitations of the current platinum drugs, herein a multifunctional platinum(IV) compound 1 containing a histone deacetylase (HDAC) inhibitor (4-phenylbutyric acid, 4-PBA) and a tumor-targeting group (biotin) has been designed and prepared. An in vitro cytotoxicity study indicated that compound 1 exhibits comparable or superior cytotoxicity to cisplatin against the tested cancer cell lines, but greatly reduced toxicity in human normal liver LO2 cells, implying the potential tumor-targeting ability of compound 1. Molecular docking results indicate that compound 1 can effectively interact with a biotin-specific receptor (streptavidin) through its biotin moiety, enabling potential tumor-targeting capability. Further studies indicated that compound 1's cytotoxicity stems from inducing DNA damage via the mitochondrial apoptotic pathway and inhibiting HDACs. Consequently, this compound can not only take advantage of the tumor selectively of biotin to improve its tumor-targeting ability but also strengthen its anticancer activity via simultaneously targeting DNA and HDACs.

Mubritinib enhanced the inhibiting function of cisplatin in lung cancer by interfering with mitochondrial function

Background

Lung cancer is one of the most lethal cancers worldwide. Cisplatin, a widely used anti‐lung cancer drug, has been limited in clinical application due to its drug resistance. Medicines targeting mitochondrial electron transport chain (ETC) complexes may be effective candidates for cisplatin‐based chemotherapy.

Methods

In this study, the small molecule drug library from Food and Drug Administration FDA was used to screen for medicines targeting ETC. MTT and colony formation assays were used to investigate cell proliferation. Flow cytometry was employed to analyze cell cycle, apoptosis, reactive oxygen species (ROS), and mitochondrial membrane potential. Wound scratch and transwell assays were used to detect migration and invasion abilities. The activities of the ETC complex were tested using kits. Western blot analysis was used to investigate the expressions of related proteins. A mouse xenograft model was constructed to verify the antitumor effect in vivo.

Results

The results showed that mubritinib can reduce the activation of the PI3K/mTOR signal pathway, disrupt mitochondrial function, significantly increase ROS levels and induce oxidative stress, and ultimately exert its antitumor effect against non‐small cell lung cancer (NSCLC) both in vivo and in vitro. In addition, the combination of cisplatin and mubritinib can improve the tumor‐suppressive effect of cisplatin.

Conclusion

Mubritinib can upregulate intracellular ROS concentration and cell apoptosis, inhibit the PI3K signaling pathway and interfere with the function of mitochondria, thus reducing cell proliferation and increasing ROS induced apoptosis by reducing the activation of Nrf2 by PI3K.

Metallodrugs in cancer nanomedicine

Metal complexes are extensively used for cancer therapy. The multiple variables available for tuning (metal, ligand, and metal-ligand interaction) offer unique opportunities for drug design, and have led to a vast portfolio of metallodrugs that can display a higher diversity of functions and mechanisms of action with respect to pure organic structures. Clinically approved metallodrugs, such as cisplatin, carboplatin and oxaliplatin, are used to treat many types of cancer and play prominent roles in combination regimens, including with immunotherapy. However, metallodrugs generally suffer from poor pharmacokinetics, low levels of target site accumulation, metal-mediated off-target reactivity and development of drug resistance, which can all limit their efficacy and clinical translation. Nanomedicine has arisen as a powerful tool to help overcome these shortcomings. Several nanoformulations have already significantly improved the efficacy and reduced the toxicity of (chemo-)therapeutic drugs, including some promising metallodrug-containing nanomedicines currently in clinical trials. In this critical review, we analyse the opportunities and clinical challenges of metallodrugs, and we assess the advantages and limitations of metallodrug delivery, both from a nanocarrier and from a metal-nano interaction perspective. We describe the latest and most relevant nanomedicine formulations developed for metal complexes, and we discuss how the rational combination of coordination chemistry with nanomedicine technology can assist in promoting the clinical translation of metallodrugs.

Engineering Supramolecular Nanomedicine for Targeted Near Infrared-triggered Mitochondrial Dysfunction to Potentiate Cisplatin for Efficient Chemophototherapy

Combinatorial cancer therapies based on nanomedicine have emerged as a promising strategy to achieve potentiated treatment efficiency. Herein, cisplatin (CDDP) prodrug (Pt-CD) and a mitochondria-targeted near-infrared (NIR) photosensitizer IR780 were combined to construct a multifunctional nanomedicine IR780@Pt NPs through a supramolecular self-assembly strategy. Targeted mitochondrial dysfunction of cancer cells was sufficiently induced under NIR laser irradiation through both photothermal and photodynamic effects, inhibiting the overactive mitochondrial energy pathways of cancer cells. The mitochondrial dysfunction significantly attenuated the crosstalk between mitochondria and nucleus via the cellular ATP energy chain, leading to obvious down-regulation of the key proteins of the nucleotide excision repair (NER) pathway. Thereby, the chemotherapeutic effect of CDDP could be significantly potentiated because of reduced DNA lesion repair capacity by ERCC1-XPF nuclease system. Moreover, IR780@Pt NPs exhibited excellent NIR fluorescence and photoacoustic (PA) imaging capacity for in vivo imaging-guided NIR laser treatment. Ultimately, the IR780@Pt NPs mediated combinatorial chemophototherapy achieved potentiated anticancer efficacy against cancer cells in vitro and tumor inhibition performance in vivo. Overall, this study highlighted the significance of nanomedicine mediated targeted induction of mitochondrial dysfunction to potentiate chemotherapy for efficient combinatorial cancer therapy.

Reactive Oxygen Species Production Is Responsible for Antineoplastic Activity of Osmium, Ruthenium, Iridium and Rhodium Half-Sandwich Type Complexes with Bidentate Glycosyl Heterocyclic Ligands in Various Cancer Cell Models

Platinum complexes are used in chemotherapy, primarily as antineoplastic agents. In this study, we assessed the cytotoxic and cytostatic properties of a set of osmium(II), ruthenium(II), iridium(III) and rhodium(III) half-sandwich-type complexes with bidentate monosaccharide ligands. We identified 5 compounds with moderate to negligible acute cytotoxicity but with potent long-term cytostatic activity. These structure-activity relationship studies revealed that: (1) osmium(II) p-cymene complexes were active in all models, while rhodium(III) and iridium(III) Cp* complexes proved largely inactive; (2) the biological effect was influenced by the nature of the central azole ring of the ligands—1,2,3-triazole was the most effective, followed by 1,3,4-oxadiazole, while the isomeric 1,2,4-oxadiazole abolished the cytostatic activity; (3) we found a correlation between the hydrophobic character of the complexes and their cytostatic activity: compounds with O-benzoyl protective groups on the carbohydrate moiety were active, compared to O-deprotected ones. The best compound, an osmium(II) complex, had an IC₅₀ value of 0.70 µM. Furthermore, the steepness of the inhibitory curve of the active complexes suggested cooperative binding; cooperative molecules were better inhibitors than non-cooperative ones. The cytostatic activity of the active complexes was abolished by a lipid-soluble antioxidant, vitamin E, suggesting that oxidative stress plays a major role in the biological activity of the complexes. The complexes were active on ovarian cancer, pancreatic adenocarcinoma, osteosarcoma and Hodgkin’s lymphoma cells, but were inactive on primary, non-transformed human fibroblasts, indicating their applicability as potential anticancer agents.

When ferrocene and diiron organometallics meet: triiron vinyliminium complexes exhibit strong cytotoxicity and cancer cell selectivity

Robust and versatile cationic triiron complexes, obtained from the assembly of ferrocenyl with a di-organoiron structure, display an outstanding cytotoxicity profile, which may be related to redox processes provided by the two metallic components.

Anticancer ruthenium(ii) tris(pyrazolyl)methane complexes with bioactive co-ligands

New anticancer RuII-tpm complexes are presented, including a synthetic strategy to tether bioactive molecules to the metallic scaffold.

Promoted antitumor therapy on pancreatic cancer by a novel recombinant human albumin-bound miriplatin nanoparticle

Pancreatic cancer is an aggressive and highly lethal disease with a very poor prognosis. Our previous study found miriplatin can inhibit proliferation of various tumor cells, including pancreatic cancer cells. For the chemotherapy of pancreatic cancer, a novel recombinant human serum albumin (rHSA)-bound miriplatin nanoparticles (rHSA-miPt) were constructed by emulsion-diffusion evaporation method. The optimal formulation was composed of 150 mg of rHSA and 30 mg of miriplatin. The key parameters in rHSA-miPt production were 10 min of high-pressure homogenization in a solution with volume ratio of 10:2 of 5% glucose and chloroform. The rHSA-miPt was characterized with a particle size of 61 ± 10 nm, a zeta potential value of -18 ± 5 mV, encapsulation efficiency of 98.4%, drug loading of 16.4%, T_1/2 of 13.3 h and V_d of 0.5 L in Sprague Dawley rats. The concentrations of platinum (Pt) in the tumors were 15 and 22-fold higher than those in the blood at 24 and 72 h in tumor-bearing mice, respectively. The internalization of rHSA-miPt through caveolae-dependent pathway. In vitro, the half-maximal inhibitory concentration (IC₅₀) of rHSA-miPt was 12.7 μM vs more than 100 μM of gemcitabine (Gem). The inhibition rate of tumor growth was 76% of rHSA-miPt and 51% of Gem, respectively. Compared with Gem, rHSA-miPt was identified to be safer and less toxic based on body weight loss in mice (0% vs 20%), the survival rate of mice (100% vs 80%) and hematological and biochemical parameters of the mice including leukocytes, lymphocytes, neutrophils, monocytes, serum alanine aminotransferase and aspartate aminotransferase. The present study revealed that rHSA-miPt might be a promising candidate for pancreatic cancer therapy.

Ruthenium Half-Sandwich Type Complexes with Bidentate Monosaccharide Ligands Show Antineoplastic Activity in Ovarian Cancer Cell Models through Reactive Oxygen Species Production

Ruthenium complexes are developed as substitutes for platinum complexes to be used in the chemotherapy of hematological and gynecological malignancies, such as ovarian cancer. We synthesized and screened 14 ruthenium half-sandwich complexes with bidentate monosaccharide ligands in ovarian cancer cell models. Four complexes were cytostatic, but not cytotoxic on A2780 and ID8 cells. The IC₅₀ values were in the low micromolar range (the best being 0.87 µM) and were similar to or lower than those of the clinically available platinum complexes. The active complexes were cytostatic in cell models of glioblastoma, breast cancer, and pancreatic adenocarcinoma, while they were not cytostatic on non-transformed human skin fibroblasts. The bioactive ruthenium complexes showed cooperative binding to yet unidentified cellular target(s), and their activity was dependent on reactive oxygen species production. Large hydrophobic protective groups on the hydroxyl groups of the sugar moiety were needed for biological activity. The cytostatic activity of the ruthenium complexes was dependent on reactive species production. Rucaparib, a PARP inhibitor, potentiated the effects of ruthenium complexes.

The Effect of Shenyi Capsule on Non-Small-Cell Lung Cancer Combined with Chemotherapy from the Yin-Yang Perspective

As an example of Shenyi capsule on non-small-cell lung cancer combined with chemotherapy, this review discusses the synergistic effect and mechanism of natural drugs in oncotherapy from the yin-yang perspective in ancient Chinese philosophy, so as to reflect the therapeutic principle of natural drugs for tumor more comprehensively. The major focuses of this review are on the philosophical thinking of yin-yang as a tool which can not only explain the effect of Shenyi capsule in NSCLC combined with chemotherapy but also explore the mechanism of Shenyi capsule at the cellular and molecular level. Learning from the "yin-yang" thinking of ancient Chinese philosophy will bring more enlightenment to the research and development of traditional Chinese drugs in the future.

Anticancer Diiron Vinyliminium Complexes: A Structure-Activity Relationship Study

A series of 16 novel diiron complexes of general formula [Fe2Cp2(CO)(μ-CO){μ-η1:η3-C(R')C(R″)CN(R)(Y)}]CF3SO3 (2-7), bearing different substituents on the bridging vinyliminium ligand, was synthesized in 69-95% yields from the reactions of diiron μ-aminocarbyne precursors with various alkynes. The products were characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy; moreover the X-ray structures of 2c (R = Y = CH2Ph, R' = R″ = Me) and 3a (R = CH2CH=CH2, Y = R' = Me, R″ = H) were ascertained by single-crystal X-ray diffraction studies. NMR and UV-Vis methods were used to assess the D2O solubility, the stability in aqueous solution at 37 °C and the octanol-water partition coefficients of the complexes. A screening study evidenced a potent cytotoxicity of 2-7 against the A2780 cancer cell line, with a remarkable selectivity compared to the nontumoral Balb/3T3 cell line; complex 4c (R = Cy, Y = R' = R″ = Me) revealed as the most performant of the series. The antiproliferative activity of a selection of complexes was also assessed on the cisplatin-resistant A2780cisR cancer cell line, and these complexes were capable of inducing a significant ROS production. Moreover, ESI-MS experiments indicated the absence of interaction of selected complexes with cytochrome c and the potentiality to inhibit the thioredoxin reductase enzyme (TrxR).

Prodrug-based nano-delivery strategy to improve the antitumor ability of carboplatin in vivo and in vitro

Chemotherapy plays a major role in the treatment of cancer, but it still has great limitations in anti-tumor effect. Carboplatin (CAR) is the first-line drug in the treatment of non-small cell lung cancer, but the therapeutic effect is demonstrated weak. Therefore, we modified CAR with hexadecyl chain and polyethylene glycol, so as to realize its liposolubility and PEGylation. The synthesized amphiphilic CAR prodrugs could self-assemble into polymer micelles in water with an average particle size about 11.8 nm and low critical micelles concentration (0.0538 mg·mL^-1). In vivo pharmacodynamics and cytotoxicity experiment evidenced that the polymer micelles were equipped with preferable anti-tumor effect, finally attained the aim of elevating anti-tumor effect and prolonging retention time in vivo. The self-assembled micelles skillfully solve the shortcomings of weak efficacy of CAR, which provides a powerful platform for the application of chemical drug in oncology.

Hetero-Bis-Conjugation of Bioactive Molecules to Half-Sandwich Ruthenium(II) and Iridium(III) Complexes Provides Synergic Effects in Cancer Cell Cytotoxicity

Four bipyridine-type ligands variably derivatized with two bioactive groups (taken from ethacrynic acid, flurbiprofen, biotin, and benzylpenicillin) were prepared via sequential esterification steps from commercial 2,2'-bipyridine-4,4'-dicarboxylic acid and subsequently coordinated to ruthenium(II) p-cymene and iridium(III) pentamethylcyclopentadienyl scaffolds. The resulting complexes were isolated as nitrate salts in high yields and fully characterized by analytical and spectroscopic methods. NMR and MS studies in aqueous solution and in cell culture medium highlighted a substantial stability of ligand coordination and a slow release of the bioactive fragments in the latter case. The complexes were assessed for their antiproliferative activity on four cancer cell lines, showing cytotoxicity to the low micromolar level (equipotent with cisplatin). Additional biological experiments revealed a multimodal mechanism of action of the investigated compounds, involving DNA metalation and enzyme inhibition. Synergic effects provided by specific combinations of metal and bioactive fragments were identified, pointing toward an optimal ethacrynic acid/flurbiprofen combination for both Ru(II) and Ir(III) complexes.

Systematic Investigation of DNA Methylation Associated With Platinum Chemotherapy Resistance Across 13 Cancer Types

Background: Platinum resistance poses a significant problem for oncology clinicians. As a result, the role of epigenetics and DNA methylation in platinum-based chemoresistance has gained increasing attention from researchers in recent years. A systematic investigation of aberrant methylation patterns related to platinum resistance across various cancer types is urgently needed.

Methods: We analyzed the platinum chemotherapy response-related methylation patterns from different perspectives of 618 patients across 13 cancer types and integrated transcriptional and clinical data. Spearman’s test was used to evaluate the correlation between methylation and gene expression. Cox analysis, the Kaplan-Meier method, and log-rank tests were performed to identify potential risk biomarkers based on differentially methylated positions (DMPs) and compare survival based on DMP values. Support vector machines and receiver operating characteristic curves were used to identify the platinum-response predictive DMPs.

Results: A total of 3,703 DMPs (p value < 0.001 and absolute delta beta >0.10) were identified, and the DMP numbers of each cancer type varied. A total of 39.83% of DMPs were hypermethylated and 60.17% were hypomethylated in platinum-resistant patients. Among them, 405 DMPs (Benjamini and Hochberg adjusted p value < 0.05) were found to be associated with prognosis in tumor patients treated with platinum-based regimens, and 664 DMPs displayed the potential to predict platinum chemotherapy response. In addition, we defined six DNA DMPs consisting of four gene members (mesothelin, protein kinase cAMP-dependent type II regulatory subunit beta, msh homeobox 1, and par-6 family cell polarity regulator alpha) that may have favorable prognostic and predictive values for platinum chemotherapy.

Conclusion: The methylation-transcription axis exists and participates in the complex biological mechanism of platinum resistance in various cancers. Six DMPs and four associated genes may have the potential to serve as promising epigenetic biomarkers for platinum-based chemotherapy and guide clinical selection of optimal treatment.