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Ferritins are nanocage proteins that store iron ions in their central cavity as hydrated ferric oxide biominerals. In mammals, further the L (light) and H (heavy) chains constituting cytoplasmic maxi-ferritins, an additional type of ferritin has been identified, the mitochondrial ferritin (MTF). Human MTF (hMTF) is a functional homopolymeric H-like ferritin performing the ferroxidase activity in its ferroxidase site (FS), in which Fe(II) is oxidized to Fe(III) in the presence of dioxygen. To better investigate its ferroxidase properties, here we performed time-lapse X-ray crystallography analysis of hMTF, providing structural evidence of how iron ions interact with hMTF and of their binding to the FS. Transient iron binding sites, populating the pathway along the cage from the iron entry channel to the catalytic center, were also identified. Furthermore, our kinetic data at variable iron loads indicate that the catalytic iron oxidation reaction occurs via a diferric peroxo intermediate followed by the formation of ferric-oxo species, with significant differences with respect to human H-type ferritin.

Angiogenin (Ang) is a potent angiogenic protein that is overexpressed in many types of cancer at concentration values correlated to the tumor aggressiveness. Here, by means of an integrated multi-technique approach based on crystallographic, spectrometric and spectroscopic analyses, we demonstrate that the anti-cancer drug oxaliplatin efficiently binds angiogenin. Microscopy cellular studies, carried out on the prostate cancer cell (PC-3) line , show that oxaliplatin inhibits the angiogenin prompting effect on cell proliferation and migration, which are typical features of angiogenesis process. Overall, our findings point to angiogenin as a possible target of oxaliplatin, thus suggesting a potential novel mechanism for the antineoplastic activity of this platinum drug and opening the avenue to novel approaches in the combined anti-cancer anti-angiogenic therapy.

The use of Pt(iv) complexes as potential anticancer drugs is attractive, because they have higher stability and less side effects than Pt(ii) compounds. Moreover, some Pt(iv) complexes can also be activated with light, opening an avenue to photochemotherapy. Our purpose is to widen the library of photoactivatable Pt(iv)-based prodrugs and here we report on the oxidation of the Pt(ii) compound [PtCl(4'-phenyl-2,2':6',2''-terpyridine)][CF3SO3] (1) with PhICl2 or H2O2. The synthetic procedure avoids the formation of multiple species: the treatment with PhICl2 produces the Pt(iv) complex with axial chlorides, [PtCl3(4'-phenyl-2,2':6',2''-terpyridine)][CF3SO3] (2), while H2O2 oxidation and post-synthesis carboxylation produce [Pt(OCOCH3)2Cl(4'-phenyl-2,2':6',2''-terpyridine)][CF3SO3] (3), bearing acetates in the axial positions. 2 and 3 are stable in physiological-like buffers and in DMSO in the dark, but undergo photoreduction to 1 upon irradiation at 365 nm. Their stability toward reduction is a fundamental parameter to consider: cyclic voltammetry experiments show that the 2 electron reduction Pt(iv) → Pt(ii) occurs at a more negative potential for 3, because of the greater stabilization provided by the acetate axial groups; noteworthily, 3 is stable for hours also in the presence of mM concentration of glutathione. The cytotoxicity of 2 and 3 toward A2780 and A2780cis cell lines reveals that 3 is the least toxic in the dark, but is able to produce cytotoxic effects far higher than cisplatin when irradiated. To shed light on the mechanistic aspects, the interaction with protein and DNA models has been explored through high-resolution mass spectrometry revealing that 2 and 3 behave as prodrugs, but are able to bind to biological targets only after irradiation.

This article provides an overview of the various research approaches we have explored in recent years to improve metal-based agents for cancer or infection treatments. Although cisplatin, carboplatin, and oxaliplatin remain the cornerstones in tumor chemotherapy, the discovery and approval of novel inorganic anticancer drugs is a very slow process. Analogously, although a few promising inorganic drugs have found clinical application against parasitic or bacterial infections, their use remains relatively limited. Moreover, the discovery process is often affected by small therapeutic enhancements that are not attractive for the pharmaceutical industry. However, the availability of increasing mechanistic information for the modes of action of established inorganic drugs is fueling the exploration of various approaches for developing effective inorganic chemotherapy agents. Through a series of examples, some from our own research experience, we focus our attention on a number of promising strategies, including (1) drug repurposing, (2) the simple modification of the chemical structures of approved metal-based drugs, (3) testing novel drug combinations, and (4) newly synthesized complexes coupling different anticancer drugs. Accordingly, we aim to suggest and summarize a series of reliable approaches that are exploitable for the development of improved and innovative treatments.

Chloro(triethylphosphine)gold(I), (Et3PAuCl hereafter), is an Auranofin (AF)-related compound showing very similar biological and pharmacological properties. Like AF, Et3PAuCl exhibits potent antiproliferative properties in vitro toward a variety of cancer cell lines and is a promising anticancer drug candidate. We wondered whether Et3PAuCl encapsulation might lead to an improved pharmacological profile also considering the likely reduction of unwanted side-reactions that are responsible for adverse effects and for drug inactivation. Et3PAuCl was encapsulated in biocompatible PLGA–PEG nanoparticles (NPs) and the new formulation evaluated in colorectal HCT-116 cancer cells in comparison to the free gold complex. Notably, encapsulated Et3PAuCl (nano-Et3PAuCl hereafter) mostly retains the cellular properties of the free gold complex and elicits even greater cytotoxic effects in colorectal cancer (CRC) cells, mediated by apoptosis and autophagy. Moreover, a remarkable inhibition of two crucial signaling pathways, i.e. ERK and AKT, by nano-Et3PAuCl, was clearly documented. The implications of these findings are discussed.

In this paper it is demonstrated that the nature of the ligands of two Ru2(II,III) paddlewheel complexes dramatically affects the overall anticancer properties in cells. Herein, the complex [Ru2(EB776)4Cl] was found to be more active against a glioblastoma model with respect to its isomer [Ru2(EB106)4Cl]. These different effects depend on the steric hindrance, on the allowed conformations of the complexes and on the presence of hydrophilic regions in [Ru2(EB776)4Cl], which overall lead to a lower “steric protection”.

Electrospray ionization mass spectrometry (ESI MS) is a powerful investigative tool to analyze the reactions of metallodrugs with proteins and peptides and characterize the resulting adducts. Here, we have applied this type of approach to four experimental anticancer gold(III) compounds for which extensive biological and mechanistic data had previously been gathered, namely, Auoxo6, Au2phen, AuL12, and Aubipyc. These gold(III) compounds were reacted with two representative proteins, i.e., human serum albumin (HSA) and human carbonic anhydrase I (hCA I), and with the C-terminal dodecapeptide of thioredoxin reductase. ESI MS analysis allowed us to elucidate the nature of the resulting metal-protein adducts from which the main features of the occurring metallodrug-protein reactions can be inferred. In selected cases, MS data were integrated and supported by independent 1HNMR and UV-Vis absorption measurements to gain an overall description of the occurring processes. From data analysis, it emerges that most of the investigated gold(III) complexes, endowed with an appreciable oxidizing character, undergo quite facile reduction to gold(I); the resulting gold(I) species tightly associate with the above proteins/peptides with a remarkable selectivity for free cysteine residues. In contrast, in the case of the less-oxidizing Aubipyc complex, the gold(III) oxidation state is conserved, and a gold(III) fragment still containing the original ligand is found to be associated with the target proteins. It is notable that the C-terminal dodecapeptide of thioredoxin reductase containing the characteristic -Gly-Cys-Sec-Gly metal-binding motif is able in all cases to trigger gold(III)-to-gold(I) reduction. Our investigation allowed us to identify in detail the nature of the gold fragments that ultimately bind the protein targets and determine the exact binding stoichiometry; some insight on the reaction kinetics was also gained. Notably, a few clear correlations could be established between the structure of the metal complexes and the nature of the resulting protein adducts. The mechanistic implications of these findings are analyzed and thoroughly discussed. Overall, the present results set the stage to better understand the real target biomolecules of these gold compounds and elucidate at the atomic level their interaction modes with proteins and peptides.

The clinically established gold drug Auranofin was reacted individually with a group of representative proteins, namely ubiquitin, ribonuclease A, carbonic anhydrase, haemoglobin and superoxide dismutase, and adduct formation was monitored in the various cases by ESI-MS analysis. We found that the reaction is highly selective for solvent exposed free cysteines that are modified through coordination of the AuPEt3+ fragment. Indeed, ESI-Q-TOF MS spectra carried out on protein samples incubated with a three fold molar excess of Auranofin allowed direct detection of the native proteins bearing bound AuPEt3+ fragments in the cases of carbonic anhydrase and haemoglobin. At variance, the two proteins that do not possess any free cysteine residue, i.e. ubiquitin and ribonuclease A, were unable to bind the gold fragment. In the case of superoxide dismutase, adduct formation is hindered by the scarce solvent accessibility of the free cysteine residue. These findings were further confirmed by a series of competition binding experiments with ebselen, a potent and selective cysteine-modifying reagent; we observed that pre-treatment with ebselen prevents the binding of the AuPEt3+ fragment to both carbonic anhydrase and haemoglobin.

Au(PEt3)I (AF-I hereafter), the iodide analog of the FDA-approved drug auranofin (AF hereafter), is a promising anticancer agent that produces its pharmacological effects through interaction with non-genomic targets such as the thioredoxin reductase system. AF-I is endowed with a very favorable biochemical profile showing potent in vitro cytotoxic activity against several cancer types including ovarian and colorectal cancer. Remarkably, in a recent publication, some of us reported that AF-I induces an almost complete and rapid remission in an orthotopic in vivo mouse model of ovarian cancer. The cytotoxic potency does not bring about highly severe side effects, making AF-I very well-tolerated even for higher doses, even more so than the pharmacologically active ones. All these promising features led us to expand our studies on the mechanistic aspects underlying the antitumor activity of AF-I. We report here on an integrated experimental and theoretical study on the reactivity of AF-I, in comparison with auranofin, toward relevant aminoacidic residues or their molecular models. Results point out that the replacement of the thiosugar moiety with iodide significantly affects the overall reactivity toward the amino acid residues histidine, cysteine, methionine, and selenocysteine. Altogether, the obtained results contribute to shed light into the enhanced antitumoral activity of AF-I compared with AF.

The reactions of auranofin and three pseudohalide derivatives with bovine serum albumin were explored by ESI-Q-TOF mass spectrometry; a detailed molecular description of the resulting adducts is achieved revealing even subtle differences in reactivity within this series of gold(I) complexes. Our study shows that this kind of investigative approach, formerly applied to the interactions of metal-based drugs with small model proteins of MW 10-15 kDa, e.g., cytochrome c and lysozyme, may now be extended with success to far larger proteins such as serum albumin (MW 66 kDa).

Despite the widespread use of platinum drugs in the treatment of colorectal cancer (CRC), due to the heavy side effects and to intrinsic or acquired Pt resistance, new and more efficient drugs are urgently needed. Starting from the encouraging results obtained for the complex PtI2(DACH), we summarise here our recent advances, reporting data on the synthesis and the chemical and biological features of two oxaliplatin analogues i.e. PtBr2(DACH) and PtCl2(DACH). The comparative approach of these studies reveals how these analogues possess interesting and differential pharmacological properties as well as some peculiar features that may be conveniently exploited to shed light in the mechanistic aspects involved in the pharmacological action of the parent drug oxaliplatin. Furthermore, these findings may inspire the design of more effective Pt-based anticancer drugs to be used in CRC treatment.

Gold compounds form an attractive class of cytotoxic metal compounds of potential application as anticancer agents. Notably, the mode of action of cytotoxic gold compounds appears to differ from that of the widely used anticancer Pt drugs -to which they were initially inspired- and to be basically DNA-independent. However, mechanistic details are still largely lacking for this class of metal-based drugs. To shed light on these issues we have developed a proteomic strategy that is capable of highlighting the perturbations in protein expression elicited by gold drugs in a selected cancer cell line with the final aim to disclose the underlying molecular mechanisms. In recent years, this type of strategy has been systematically applied, in our laboratory, to a representative panel of gold compounds including seven outstanding cytotoxic agents, i.e. six experimental gold(III) and gold(I) compounds and the clinical gold(I) drug, auranofin. A2780 human ovarian cancer cells were used as the standard cellular model for these studies. Proteins differentially expressed upon treatment were separated by 2-DE and identified by MALDI TOF and their meaning tentatively assessed through bioinformatic analysis. The occurrence of various and often overlapping molecular mechanisms was revealed. The affected proteins were found to belong -in most cases- to redox control systems and/or to the proteasome machinery implying that the severe cellular damage induced by gold compounds predominantly originates at these two distinct levels. However, for one Au(III) and one Au(I) compound, i.e. [(bipydmb-H)Au(OH)][PF6] (bipydmb-H = deprotonated 6-(1,1-dimethylbenzyl)-2,2′-bipyridine) (Aubipyc) and the bis(1-butyl-3-methyl-imidazole-2-ylidene) gold(I) [Au(NHC)2]PF6, a substantially greater number of proteomic alterations were detected pointing out, in both cases, to glucose metabolism as an additional target process of the cytotoxic action. The results that were obtained with the seven gold complexes are discussed in the frame of the available knowledge on anticancer gold drugs and their mechanisms. In general, our studies underscore the large amount of information that proteomic measurements may provide on the mode of action of metal-based drugs at the cellular level and delineate a very effective methodology for the identification of the respective cytotoxic mechanisms. We propose that the interpretation of the proteomic data in terms of the main affected cellular processes is further supported and validated through the implementation of complementary metabolomics and metallomics experiments.

// Ida Landini 1 , Andrea Lapucci 1 , Alessandro Pratesi 2 , Lara Massai 2 , Cristina Napoli 3 , Gabriele Perrone 1 , Pamela Pinzani 4 , Luigi Messori 2, * , Enrico Mini 1, * and Stefania Nobili 3, * 1 Department of Experimental and Clinical Medicine, University of Florence, Firenze, Italy 2 Department of Chemistry “Ugo Schiff”, University of Florence, Firenze, Italy 3 Department of Health Sciences, University of Florence, Firenze, Italy 4 Department of Experimental and Clinical Biomedical Sciences, University of Florence, Firenze, Italy * These authors have contributed equally to this work Correspondence to: Enrico Mini, email: enrico.mini@unifi.it Stefania Nobili, email: stefania.nobili@unifi.it Luigi Messori, email: luigi.messori@unifi.it Keywords: auranofin; tumour drug resistance; human tumour cell lines; drug effects; gene expression Received: March 24, 2017 Accepted: August 08, 2017 Published: October 09, 2017 ABSTRACT The anti-arthritic drug auranofin exerts also potent antitumour activity in in vitro and in vivo models, whose mechanisms are not yet well defined. From an auranofin-sensitive human ovarian cancer cell line A2780, a highly resistant (>20-fold) subline (A2780/AF-R) was developed and characterized. Marked reduction of gold accumulation occurred in auranofin-resistant A2780 cells. Also, moderately higher thioredoxin reductase activity in A2780/AF-R cells was observed while no changes in intracellular glutathione content occurred. Resistance to auranofin was associated with a low level of cross-resistance to some investigational gold compounds as well as to oxaliplatin and other anticancer drugs with different mode of action (i.e. melphalan, vinblastine, doxorubicin, etoposide, and paclitaxel). Reduced gold accumulation was associated to substantial gene expression changes in various influx (e.g. SLC22A1, SLC47A1, SLCO1B1 ) and efflux (e.g. ABCB1, ABCC2, ABCC3 ) transporters. The expression levels of selected proteins (i.e. SLC22A1, SLC47A1, P-gp) were also changed accordingly. These data provide evidence that multiple drug transporters may act as mediators of transport of auranofin and other gold compounds in cancer cells. Further investigation into the molecular mechanisms mediating transport of auranofin and new gold complexes in view of their potential clinical application in the treatment of cancer is warranted.

The solution behavior of auranofin, Et3PAuCl and Et3PAuI, as well as their interactions with hen egg white lysozyme, single strand oligonucleotide, and ds-DNA were comparatively analyzed through NMR spectroscopy, ESI-MS, ethidium bromide displacement, DNA melting and viscometric tests. The cytotoxic effects toward representative colorectal cancer cell lines were found to be strong and similar in the three cases and a good correlation could be established between the cytotoxicity and the ability to inhibit thioredoxin reductase; remarkably, in vivo acute toxicity experiments for Et3PAuI confirmed that, similarly to auranofin, this drug is well tolerated in a murine model. Overall, a very similar profile emerges for Et3PAuI and Et3PAuCl, which retain the potent cytotoxic effects of auranofin while showing some peculiar features. These results demonstrate that the presence of the thiosugar moiety is not mandatory for the pharmacological action, suggesting that the tuning of some relevant chemical properties...

The ruthenium-arene complexes [(η6-p-cymene)RuCl2(κP-PPh2(4-C6H4CO2H))], 1, [(η6-p-cymene)RuCl(κ2P,O-PPh2(2-C6H4CO2))], 2, [(η6-p-cymene)RuCl2(κP-PPh2(2-C6H4OCO-EA))], 3, and [(η6-p-cymene)RuCl2(κP-PPh2(4-C6H4CO2CH2CH2OCO-EA))], 4 (EA-CO2H = ethacrynic acid), were synthesized in good to high yields and characterized by analytical techniques, IR, UV-Vis and multinuclear NMR spectroscopy, and single crystal X-ray diffraction in the cases of 1 and 2. The unstable compounds [(η6-arene)RuCl2(κP-PPh2(2-C6H4CO2CH2CH2OCO-EA))] (arene = p-cymene, 5a; arene = C6H6, 5b) were obtained and identified in solution by NMR. Electrochemical and spectro-electrochemical experiments were performed in order to assess the redox behaviour of 1-4 in CH2Cl2. The in vitro cytotoxicity of 1-4 was determined on the human pancreatic cancer cell line BxPC3 and the mouse embryo fibroblast Balb/3T3 Clone A31 cell line, the latter acting as a model for normal cells. Furthermore, the interaction of 1, 3 and 4 with two model proteins was investigated by high resolution ESI-MS.

Three pseudohalide analogues of the established gold drug auranofin (AF hereafter), of general formula Au(PEt3)X, i.e. Au(PEt3)CN, Au(PEt3)SCN and Au(PEt3)N3 (respectively denoted as AFCN, AFSCN and AFN3), were prepared and characterized. The crystal structure was solved for Au(PEt3)SCN highlighting the classical linear geometry of the 2-coordinate gold(I) center. The solution behaviour of the compounds was then comparatively analysed through 31PNMR providing evidence for an acceptable stability under physiological-like conditions. Afterward, the reaction of these gold compounds with bovine serum albumin (BSA) and consequent adduct formation was investigated by 31PNMR. For all the studied gold compounds, the [Au(PEt3)]+ moiety was identified as the reactive species in metal/protein adducts formation. The cytotoxic effects of the complexes were subsequently measured in comparison to AF against a representative colorectal cancer cell line and found to be still relevant and roughly similar in the three cases though far weaker than those of AF. These results show that the nature of the anionic ligand can modulate importantly the pharmacological action of the gold-triethylphosphine moiety, affecting the cytotoxic potency. These aspects may be further explored to improve the pharmacological profiles of this family of metal complexes.

[Image: see text] In recent years, a few successful attempts were made to repurpose the clinically approved antiarthritic gold drug, Auranofin (AF), as an anticancer agent. The present study shows that the iodido(triethylphosphine)gold(I) complex, (Et(3)PAuI hereafter)—an AF analogue where the thiosugar ligand is simply replaced by one iodide ligand—manifests a solution chemistry resembling that of AF and exerts similar cytotoxic and proapoptotic effects on A2780 human ovarian cancer cells in vitro. However, when evaluated in a preclinical orthotopic model of ovarian cancer, Et(3)PAuI produces a far superior anticancer action than AF inducing a nearly complete tumor remission. The highly promising in vivo performances here documented for Et(3)PAuI warrant its further evaluation as a drug candidate for ovarian cancer treatment.

The reactions with a few model proteins of two structurally related gold carbene compounds, namely the gold(I) monocarbene complex Au(NHC)Cl and the corresponding bis-carbene complex [Au(NHC)2]PF6 (where NHC is an N-heterocyclic carbene ligand), were comparatively studied by ESI MS measurements. The investigated proteins were: human serum albumin, human carbonic anhydrase and bovine superoxide dismutase; in addition, the reactions of the two gold carbenes with the C-terminal synthetic dodecapeptide of thioredoxin reductase were analyzed. Formation of metallodrug-protein adducts was observed in all cases made exception for the reactions of [Au(NHC)2]PF6 with carbonic anhydrase and superoxide dismutase. Notably, in line with expectations, the monocarbene gold complex turned out to be more effective than its dicarbene counterpart in forming protein adducts. The reactivity of these gold carbene complexes with model proteins is compared to that of a few other gold(III) and gold(I) complexes whose reactions with model proteins had been previously investigated with the same methodology; it emerges that the two gold carbenes react more selectively with proteins at well-defined anchoring sites. The implications of these results are discussed in the light of the current knowledge on medicinal gold compounds.

// Francesca Magherini 1 , Tania Fiaschi 1 , Elisa Valocchia 1 , Matteo Becatti 1 , Alessandro Pratesi 2 , Tiziano Marzo 2, 3 , Lara Massai 2 , Chiara Gabbiani 3 , Ida Landini 4 , Stefania Nobili 5 , Enrico Mini 5 , Luigi Messori 2 , Alessandra Modesti 1 and Tania Gamberi 1 1 Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, Florence, Italy 2 Department of Chemistry “Ugo Schiff”, University of Florence, Florence, Italy 3 Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa, Italy 4 Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy 5 Department of Health Sciences, University of Florence, Florence, Italy Correspondence to: Tania Gamberi, email: tania.gamberi@unifi.it Luigi Messori, email: luigi.messori@unifi.it Keywords: gold(I)-N-heterocyclic carbene complexes; A2780 human ovarian cancer cells; proteomics; mitochondrial metabolism; thioredoxin reductase Received: August 13, 2017 Accepted: May 19, 2018 Published: June 15, 2018 ABSTRACT Au(NHC) and Au(NHC) 2 , i.e. a monocarbene gold(I) complex and the corresponding bis(carbene) complex, are two structurally related compounds, endowed with cytotoxic properties against several cancer cell lines. Herein, we explore the molecular and cellular mechanisms at the basis of their cytotoxicity in A2780 human ovarian cancer cells. Through a comparative proteomic analysis, we demonstrated that the number of modulated proteins is far larger in Au(NHC) 2 -treated than in Au(NHC)-treated A2780 cells. Both gold compounds mainly affected proteins belonging to the following functional classes: protein synthesis, metabolism, cytoskeleton and stress response and chaperones. Particularly, Au(NHC) 2 gave rise to an evident upregulation of several glycolytic enzymes. Moreover, only Au(NHC) 2 triggered a net impairment of respiration and a metabolic shift towards glycolysis, suggesting that mitochondria are relevant cellular targets. We also found that both carbenes, similarly to the gold(I) compound auranofin, caused a strong inhibition of the seleno-enzyme thioredoxin reductase (TrxR). In conclusion, we highlighted that coordination of two carbene ligands to the same gold(I) center greatly enhances the antiproliferative effects of the resulting compound in comparison to the monocarbene derivative. Moreover, TrxR inhibition and metabolic impairment seem to play a major role in the Au(NHC) 2 cytotoxicity. Overall, these antiproliferative effects were also confirmed on other two human ovarian cancer cell lines ( i.e. SKOV3 and IGROV1).

In vivo somatostatin receptor scintigraphy is a valuable method for the visualization of human endocrine tumours and their metastases. In fact, peptide ligands of somatostatin receptors (sst’s) conjugated with chelating agents are in clinical use. We have recently developed octreotide dicarba-analogues, which show interesting binding profiles at sst’s. In this context, it was mandatory to explore the possibility that our analogues could maintain their activity also upon conjugation with DOTA. In this paper, we report and discuss the synthesis, binding affinity and conformational preferences of three DOTA-conjugated dicarba-analogues of octreotide. Interestingly, two conjugated analogues exhibited nanomolar affinities on sst2 and sst5 somatostatin receptor subtypes.

Since the first approval of cisplatin for cancer treatment in 1978, a lot of attempts have been carried out to characterize in detail its interactions with serum albumin, by far the most important and most abundant plasma protein. The state of the art of those studies was recapitulated by Keppler and coworkers in a comprehensive review article which appeared in Chem. Rev. in 2006. Yet, the general picture was still rather incomplete at that time due to the lack of conclusive structural data. We report here on the main achievements obtained on this system in the period 2006–2018 and try to describe what is now clearly ascertained and what are the still open issues. Remarkably, a detailed structural characterization of this metallodrug/protein system was recently gained thanks to the resolution of the crystal structure of a cisplatin/serum albumin adduct; crystallographic results are nicely complemented by independent MS data. Accordingly, detailed information is obtained on the number and the location of the platinum binding sites. In turn, metallomics investigations permitted to monitor platination of this serum protein in real blood samples. Thus, a rather complete molecular description of the system could be achieved. Conversely, the biological and pharmacological profiles of platinum drugs/serum albumin adducts were drafted in a couple of specific studies; however the results on theses issue are in our opinion still preliminary and controversial and more studies are needed, aimed in particular at establishing clear correlations between the nature of the various platinum/serum albumin derivatives and their biological actions. In any case, the relevance and the impact of cisplatin/serum albumin adducts are herein highlighted and future perspectives briefly depicted.

KV11.1 (hERG1) channels are often overexpressed in human cancers. In leukemias, KV11.1 regulates pro-survival signals that promote resistance to chemotherapy, raising the possibility that inhibitors of KV11.1 could be therapeutically beneficial. However, because of the role of KV11.1 in cardiac repolarization, blocking these channels may cause cardiac arrhythmias. We show that CD-160130, a novel pyrimido-indole compound, blocksKV11.1 channels with a higher efficacy for the KV 11.1 isoform B, in which the IC50 (1.8 μM) was approximately 10-fold lower than observed in KV 11.1 isoform A. At this concentration, CD-160130 also had minor effects on Kir 2.1, KV 1.3,KV1.5, and KCa 3.1. In vitro, CD-160130 induced leukemia cell apoptosis, and could overcome bone marrow mesenchymal stromal cell (MSC)-induced chemoresistance. This effect was caused by interference with the survival signaling pathways triggered by MSCs. In vivo, CD-160130 produced an antileukemic activity, stronger than that caused by cytarabine. Consistent with its atypical target specificity, CD-160130 did not bind to the main binding site of the arrhythmogenicKV11.1 blockers (the Phe656 pore residue). Importantly, in guinea pigs CD-160130 produced neither alteration of the cardiac action potential shape in dissociated cardiomyocytes nor any lengthening of the QT interval in vivo. Moreover, CD-160130 had no myelotoxicity on human bone marrow-derived cells. Therefore, CD-160130 is a promising first-in-class compound to attempt oncologic therapy without cardiotoxicity, based on targeting KV11.1. Because leukemia and cardiac cells tend to express different ratios of the A and B KV 11.1 isoforms, the pharmacological properties of CD-160130 may depend, at least in part, on isoform specificity.

This chapter introduces the concept of the “productivity of care” and illustrates the rewarding and empowering aspects of care which are commonly overlooked. It provides empirical evidence of some of these important dimensions of care and clarifies how different types of caregivers make their way through the brighter and yet less explored dimensions of the care world.