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Background: High-grade serous ovarian carcinoma (HGSOC) is the most common and aggressive subtype of epithelial ovarian carcinoma. It is primarily diagnosed at stage III or IV when the 5-year survival rate ranges between 20% and 40%. Here, we aimed to validate the hypothesis, based on HGSOC cell lines, that proposed the existence of two distinct groups of HGSOC cells with high and low oxidative phosphorylation (OXPHOS) metabolism, respectively, which are associated with their responses to glucose and glutamine withdrawal., Methods: We isolated and cultivated primary cancer cell cultures from HGSOC and nontransformed ovarian fibroblasts from the surrounding ovarium of 45 HGSOC patients. We tested the metabolic flexibility of the primary cells, particularly in response to glucose and glutamine depletion, analyzed and modulated endoplasmic reticulum stress, and searched for indices of the existence of previously reported groups of HGSOC cells with high and low OXPHOS metabolism., Results: The primary HGSOC cells did not form two groups with high and low OXPHOS that responded differently to glucose and glutamine availabilities in the cell culture medium. Instead, they exhibited a continuum of OXPHOS phenotypes. In most tumor cell isolates, the responses to glucose or glutamine withdrawal were mild and surprisingly correlated with those of nontransformed ovarian fibroblasts from the same patients. The growth of tumor-derived cells in the absence of glucose was positively correlated with the lipid trafficking regulator FABP4 and was negatively correlated with the expression levels of HK2 and HK1. The correlations between the expression of electron transport chain (ETC) proteins and the oxygen consumption rates or extracellular acidification rates were weak. ER stress markers were strongly expressed in all the analyzed tumors. ER stress was further potentiated by tunicamycin but not by the recently proposed ER stress inducers based on copper(II)-phenanthroline complexes. ER stress modulation increased autophagy in tumor cell isolates but not in nontransformed ovarian fibroblasts., Conclusions: Analysis of the metabolism of primary HGSOC cells rejects the previously proposed hypothesis that there are distinct groups of HGSOC cells with high and low OXPHOS metabolism that respond differently to glutamine or glucose withdrawal and are characterized by ETC protein levels., (© 2024. The Author(s).)

Intact (whole) cell MALDI TOF mass spectrometry is a commonly used tool in clinical microbiology for several decades. Recently it was introduced to analysis of eukaryotic cells, including cancer and stem cells. Besides targeted metabolomic and proteomic applications, the intact cell MALDI TOF mass spectrometry provides a sufficient sensitivity and specificity to discriminate cell types, isogenous cell lines or even the metabolic states. This makes the intact cell MALDI TOF mass spectrometry a promising tool for quality control in advanced cell cultures with a potential to reveal batch-to-batch variation, aberrant clones, or unwanted shifts in cell phenotype. However, cellular alterations induced by change in expression of a single gene has not been addressed by intact cell mass spectrometry yet. In this work we used a well-characterized human ovarian cancer cell line SKOV3 with silenced expression of a tumor suppressor candidate 3 gene (TUSC3). TUSC3 is involved in co-translational N-glycosylation of proteins with well-known global impact on cell phenotype. Altogether, this experimental design represents a highly suitable model for optimization of intact cell mass spectrometry and analysis of spectral data. Here we investigated five machine learning algorithms (k-nearest neighbors, decision tree, random forest, partial least squares discrimination, and artificial neural network) and optimized their performance either in pure populations or in two-component mixtures composed of cells with normal or silenced expression of TUSC3. All five algorithms reached accuracy over 90 % and were able to reveal even subtle changes in mass spectra corresponding to alterations of TUSC3 expression. In summary, we demonstrate that spectral fingerprints generated by intact cell MALDI-TOF mass spectrometry coupled to a machine learning classifier can reveal minute changes induced by alteration of a single gene, and therefore contribute to the portfolio of quality control applications in routine cell and tissue cultures., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)

A new heteroleptic copper(II) compound named C0-UDCA was prepared by reaction of [Cu(phen) 2 (OH 2 )](ClO 4 ) 2 (C0) with the bile ursodeoxycholic acid (UDCA). The resulting compound is able to inhibit the lipoxygenase enzyme showing more efficacy than the precursors C0 and UDCA. Molecular docking simulations clarified the interactions with the enzyme as due to allosteric modulation. The new complex shows antitumoral effect on ovarian (SKOV-3) and pancreatic (PANC-1) cancer cells at the Endoplasmic Reticulum (ER) level by activating the Unfolded Protein Response. In particular, the chaperone BiP, the pro-apoptotic protein CHOP and the transcription factor ATF6 are upregulated in the presence of C0-UDCA. The combination of Intact Cell MALDI-MS and statistical analysis have allowed us to discriminate between untreated and treated cells based on their mass spectrometry fingerprints., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: As the continuation beyond progression (BP) of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) is becoming increasingly attractive for the treatment of patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC), the definition of resistance factors is crucial. The aim of the study was to investigate the impact of CDK 4/6i BP and to explore potential genomic stratification factors., Materials and Methods: We retrospectively analyzed a multi-institutional cohort of patients with HR-positive HER2-negative MBC characterized for circulating tumor DNA through next-generation sequencing before treatment start. Differences across subgroups were analyzed by chi-square test, and survival was tested by univariable and multivariable Cox regression. Further correction was applied by propensity score matching., Results: Among the 214 patients previously exposed to CDK4/6i, 172 were treated with non-CDK4/6i-based treatment (non-CDK) and 42 with CDK4/6i BP. Multivariable analysis showed a significant impact of CDK4/6i BP, TP53 single-nucleotide variants, liver involvement, and treatment line on both progression-free survival (PFS) and overall survival (OS). Propensity score matching confirmed the prognostic role of CDK4/6i BP both for PFS and OS. The favorable impact of CDK4/6i BP was consistent across all subgroups, and a differential benefit was suggested for ESR1 -mutated patients. ESR1 and RB1 mutations were more represented in the CDK4/6i BP subgroup with respect to CDK4/6i upfront., Conclusion: The study highlighted a significant prognostic impact of the CDK4/6i BP strategy with a potential added benefit in patients with ESR1 mutations suggesting the need for an extensive biomarker characterization.

The design of novel antityrosinase agents appears extremely important in medical and industrial sectors because an irregular production of melanin is related to the insurgence of several skin-related disorders (e.g., melanoma) and the browning process of fruits and vegetables. Because melanogenesis also involves a nonenzymatic oxidative process, developing dual antioxidant and antityrosinase agents is advantageous. In this work, we evaluated the antioxidant and tyrosinase inhibition ability of two new bishydroxylated and two new monohydroxylated derivatives of (1 E )-2-(1-(2-oxo-2 H -chromen-3-yl)ethylidene)hydrazine-1-carbothioamide ( T1 ) using different experimental and computational approaches. The study was also carried out on another monohydroxylated derivative of T1 for comparison. Interestingly, these molecules have more potent tyrosinase-inhibitory properties than the reference compound, kojic acid. Moreover, the antioxidant activity appears to be influenced according to the number and substitution pattern of the hydroxyl groups. The safety of the compounds without ( T1 ), with one ( T3 ), and with two ( T6 ) hydroxyl groups, has also been assessed by studying their cytotoxicity on melanocytes. These results indicate that (1 E )-2-(1-(2-oxo-2H-chromen-3-yl)ethylidene)hydrazine-1-carbothioamide and its hydroxylated derivatives are promising molecules for further drug development studies.

The reactivity of 1,1'-bis(3-methyl-4-imidazolin-2-selone)methane ( L1 ) and 1,2-bis(3-methyl-4-imidazolin-2-selone)ethane ( L2 ) toward I 2 has been explored in MeCN under different experimental conditions and compared with that in CH 2 Cl 2 . The compounds [ L1' ](I) 2 ( I ), [ L1 I] n (I) n ( II ), [ L1 (μ-Se)](I) 2 ·1/2H 2 O ( III ), [ L1 I](I 3 )·2I 2 ( IV ), and [ L2 ](I) 2 ·MeCN ( V ) were obtained and characterized. X-ray diffraction analyses point out an ionic nature for these compounds, which is presumably favored by the polarity of the solvent used. In particular, [ L1 I] n (I) n ( II ) represents the first example of an iodonium complex of imidazoline-2-selone derivatives, while [ L1 (μ-Se)](I) 2 ·1/2H 2 O ( III ) represents a unique example of a dicationic [RSeSeSeR] triselane. Density functional theory calculations have allowed us to better understand the nature of the obtained compounds and to justify their formations in polarizing reaction conditions rather than in low polar solvents.

Biointerfaces are significantly affected by electrolytes according to the Hofmeister series. This work reports a systematic investigation on the effect of different metal chlorides, sodium and potassium bromides, iodides and thiocyanates, on the ESI/MS spectra of bovine serum albumin (BSA) in aqueous solution at pH = 2.7. The concentration of each salt was varied to maximize the quality of the ESI/MS spectrum, in terms of peak intensity and bell-shaped profile. The ESI/MS spectra of BSA in the absence and in the presence of salts showed a main protein pattern characterized by the expected mass of 66.5 kDa, except the case of BSA/RbCl (mass 65.3 kDa). In all systems we observed an additional pattern, characterized by at least three peaks with low intensity, whose deconvolution led to suggest the formation of a BSA fragment with a mass of 19.2 kDa. Only NaCl increased the intensity of the peaks of the main BSA pattern, while minimizing that of the fragment. NaCl addition seems to play a crucial role in stabilizing the BSA ionized interface against hydrolysis of peptide bonds, through different synergistic mechanisms. To quantify the observed specific electrolyte effects, two "Hofmeister" parameters (H s and P s ) are proposed. They are obtained using the ratio of (BSA-Salt)/BSA peak intensities for both the BSA main pattern and for its fragment. SYNOPSIS: NaCl stabilizes BSA ion and almost prevents fragmentation due to denaturing pH., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

We examine Hofmeister specific ion effects of electrolytes added to protein solution under conditions minimizing electrostatic attraction between cations and positively charged protein. Hemoglobin (Hb) in aqueous solution at the denaturing pH = 2.7 is investigated in the presence of several metal chlorides, along with sodium and potassium bromides, iodides and thiocyanates, using electrospray ionization mass spectrometry (ESI-MS). Salt concentration was varied to maximize peak intensity and bell-shaped profile in the ESI-MS spectrum. The α-chain of myoglobin is identified as the main pattern of the ESI-MS spectra in all Hb-salt systems. Both peak intensity and quality of the bell-shaped profile of the protein spectrum decrease in the cation order: K + > > Mg 2+  > Li + > > Na +  > Ca 2+  ≈ Cs +  > Rb + for Hb-Metal Chloride systems, and decrease in the anion order: Cl -  > Br -  > I -  > SCN - for systems of both Hb-NaX and Hb-KX salts. To quantify salt addition effects two Hofmeister specific electrolyte parameters H S , and P S are proposed. H S is the mean (Hb-salt)/Hb peak intensity ratio, measured for the nine peaks used for ESI-MS spectra deconvolution, taken at the same m/z values of the Hb profile. P S is the ratio between H S standard deviation and H S , and provides a specific perturbation parameter measuring the loss of protein structure. These two Hofmeister parameters give clear evidence of the effects induced either by KCl, MgCl 2 and LiCl that enhance protein peak intensity, or by NaBr, NaI, NaSCN and KSCN that induce the protein fragmentation, due to electrolyte-mediated dissociation., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Copper is an endogenous metal ion that has been studied to prepare a new antitumoral agent with less side-effects. Copper is involved as a cofactor in several enzymes, in ROS production, in the promotion of tumor progression, metastasis, and angiogenesis, and has been found at high levels in serum and tissues of several types of human cancers. Under these circumstances, two strategies are commonly followed in the development of novel anticancer Copper-based drugs: the sequestration of free Copper ions and the synthesis of Copper complexes that trigger cell death. The latter strategy has been followed in the last 40 years and many reviews have covered the anticancer properties of a broad spectrum of Copper complexes, showing that the activity of these compounds is often multi factored. In this work, we would like to focus on the anticancer properties of mixed Cu(II) complexes bearing substituted or unsubstituted 1,10-phenanthroline based ligands and different classes of inorganic and organic auxiliary ligands. For each metal complex, information regarding the tested cell lines and the mechanistic studies will be reported and discussed. The exerted action mechanisms were presented according to the auxiliary ligand/s, the metallic centers, and the increasing complexity of the compound structures.

The novel copper complex [Cu(phen)2(salubrinal)](ClO4)2 (C0SAL) has been synthesised and characterised. Copper(ii) is coordinated by salubrinal through the thionic group, as shown by the UV-Vis, IR, ESI-MS and tandem mass results, together with the theoretical calculations. The formed complex showed a DPPH radical scavenging ability higher than that of salubrinal alone. Studies on lipid oxidation inhibition showed that the C0SAL concentration, required to inhibit the enzyme, was lower than that of salubrinal. The inhibition of the enzyme could take place via allosteric modulation, as suggested by docking calculations. C0SAL showed a good cytotoxic activity on A2780 cells, 82 fold higher than that of the precursor salubrinal and 1.4 fold higher than that of [Cu(phen)2(H2O)](ClO4)2. Treatment with C0SAL in SKOV3 ovarian cancer cells induced expression of GRP-78 and DDIT3 regulators of ER-stress response. The cytotoxic effect of C0SAL was reverted in the presence of TUDCA, suggesting that C0SAL induces cell death through ER-stress. In A2780 cells treated with C0SAL γ-H2AX was accumulated, suggesting that DNA damage was also involved.

Unfortunately in the online published article, the name of compound "L-salicylidenealanine" was published with incorrect spelling in the section "Synthesis of L‑salicylideneaniline (1a)". The section should correctly read as "Synthesis of L-salicylidenealanine".

Schiff bases represent a class of molecules widely studied for their importance in organic and coordination chemistry. Despite the large amount of studies on the chemical and biological properties of the Schiff bases, the different experimental conditions prevent a useful comparison to search for a correlation structure-activity. Moreover, literature is lacking in comprehensive data on the spectroscopic characterization of these compounds. For this reason, six Schiff bases, derived from salicylaldehyde and natural amino acids were fully characterized by nuclear magnetic resonance and infrared spectroscopy, and their aqueous solution equilibria, antiproliferative activity and DNA-binding activity were examined. All experimental conditions were kept constants to achieve comparable information and useful insights about their structure-activity correlation. The synthesized compounds showed DNA binding constants in the 10 1 -10 2  M -1 range, depending on the substituent present in the amino acid side-chain, and resulted devoid of significant cytotoxic activity against the different human tumor cell lines showing IC50 values higher than 100 µM.

There is an ongoing need for the development of new cancer therapeutics that combine high cytotoxic efficiency with low side effects, and also override resistance to the first-line chemotherapeutics. Copper(ii)-phenanthroline complexes are promising compounds that were shown previously to induce an immediate cytotoxic response over a panel of tumor cell lines in vitro. The molecular mechanism, however, remained unresolved. In this work we performed a thorough study of the copper(ii)-phenanthroline complexes containing different imidazolidine-2-thione ligands in ovarian cancer cells, and revealed that these complexes induce endoplasmic reticulum (ER) stress and subsequently cell death mediated by the unfolded protein response. Alleviation of the ER-stress by tauroursodeoxycholic acid (TUDCA) attenuated the cytotoxic effects. In summary, we have identified a novel, ER-dependent, molecular mechanism mediating cytotoxic effects of copper(ii)-phenanthroline complexes.

Malignant pleural mesothelioma (MPM) is a rare and aggressive form of tumour. Some mesotheliomas have been proven to be highly immunogenic. Here, we investigated the correlation between tumour infiltrating lymphocytes (TILs) or programmed cell death ligand 1 (PD-L1) expression with overall survival (OS) in patients with MPM. 62 Paraffin-embedded formalin fixed (PEFF) samples were analysed for TILs and PD-L1 expression. Patients were divided in 4 groups according to a cut-off of the percentage of TILs found per sample as measured by immunohistichemistry: "0" or absent (between 0 and 5%), "1" or low (between 6 and 25%), "2" or moderate (between 26 and 50%) and "3" or high (between 51 and 75%). OS was then correlated with different TILs' expression patterns. Moreover, PD-L1 expression was assessed within the tumour as well as in the adjacent stroma on the same samples. Higher expression of peritumoral TILs (Group 2 + 3) versus Group 0 and 1 correlated with improved OS (p-value = 0.02). On the contrary PD-L1 expression seemed to be inversely correlated with clinical outcomes, even in the absence of statistical significance (HR 1.76; p = 0.083 95% IC 0.92-3.36 in areas within the tumour; HR 1.60; p = 0.176 95%; IC 0.80-3.19 in areas within the stroma). No relationship between TILs and PD-L1 expression was identified. Our research supports the use of TILs and PD-L1 expression as potential outcome predictors in patients with MPM. The use of TILs and PD-L1 as biomarkers for checkpoint inhibitors' efficacy warrants future investigation.

Water supply from karst sources is a worldwide natural resource and the exploitation is tied to the knowledge of the positions of the hydrologic channels. We show that surface deformation induced by flood events in karst conduits is observable, and consists in uplift and outward movement from the hydraulic channel. Precipitation events produce the natural occurrence of subsurface hydraulic overpressure up to 1 MPa. Numerical modeling shows that the stresses are so strong to uplift and dislocate the surface by several mm and induce tilts in the order of microradians. The naturally induced deformation is compatible with a transient internal pressure loading of a channel. The results can be used to find new channels with dense GNSS networks. Sea water incursion and channels accessed for tourism could be monitored. Seismicity has been shown to have a seasonal variation in some areas, which could be explained by the subsurface stresses induced by the natural subsurface overpressure. The pressure induced deformation is expected to be observed in all karstic systems worldwide.

The antagonistic effect of glutathione (GSH) against the cytotoxicity of cisplatin was observed in both wild type and cisplatin-resistant human leukaemia and ovarian carcinoma cell lines. The simultaneous presence of the cytotoxic copper complex [Cu(phen) 2 (OH 2 )](ClO 4 ) 2 (C0) restored the sensitivity of the cells to cisplatin, and, at selected concentrations, led to strong synergistic effects. The C0-cisplatin-glutathione system showed a synergistic toxic effect even in the presence of 1000 μM GSH. The three-drug cocktail exerted a higher potency against leukemic cells than against freshly isolated lymphocytes from healthy donors. Compared to actively proliferating normal lymphocytes, leukaemia cells were much more susceptible to the cytocide effect of the three-drug combination and underwent the dying process(es) much faster. When the ovarian carcinoma cells were treated with cisplatin, alone or in combination with C0, late apoptotic effects were mainly observed, suggesting that DNA interactions with the C0-cisplatin complex trigger a process of programmed cell death. In contrast, the ternary combination induced apoptotic effects similar to that shown by C0 in single treatment, that is, early apoptosis. One possible explanation is that C0 and cisplatin compete for GSH-binding in the culture medium. GSH in combination with C0 and cisplatin caused a significant induction of the apoptotic process(es), through a pathway which does not compromise the integrity of the plasma membrane of cells., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Rationale: Development of therapy-resistant cancer is a major problem in clinical oncology, and there is an urgent need for novel markers identifying development of the resistant phenotype. Lipidomics represents a promising approach to discriminate lipid profiles of malignant phenotype cells. Alterations in phospholipid distribution or chemical composition have been reported in various pathologies including cancer. Here we were curious whether quantitative differences in phospholipid composition between cisplatin-resistant and -sensitive model cancer cell lines could be revealed by mass spectrometric means., Methods: The phospholipid contents of cell membranes of the cancer cell lines CCRF-CEM and A2780, both responsive and resistant to cisplatin, were analyzed by solid-phase extraction (SPE) and electrospray ionization mass spectrometry (ESI-MS and tandem mass spectrometry (MS/MS)). Extracts were obtained by disruption of cells with a dounce tissue grinder set followed by centrifugation. To minimize the enzymatic activity, phospholipids were extracted from cell extracts by SPE immediately after the cell lysis and analyzed by MS. Both supernatant and pellet fractions of cell extracts were analyzed., Results: A phospholipid profile specific for cell lines and their phenotypes was revealed. We have documented by quantitative analysis that phosphocholines PC P-34:0, PC 34:1, PC 20:2_16:0, LPC 18:1 and LPC 16:0 PLs were present in the 200-400 μM concentration range in CCRF-CEM cisplatin-responsive cells, but absent in their cisplatin-resistant cells. Similarly, PC 34:1, LPC 18:1 and LPC 16:0 were increased in cisplatin-responsive A2780 cells, and PC 20:2_16:0 was downregulated in cisplatin-resistant A2780 cells., Conclusions: In this work we showed that the ESI-MS analysis of the lipid content of the therapy-resistant and -sensitive cells can clearly distinguish the phenotypic pattern and determine the potential tumor response to cytotoxic therapy. Lipid entities revealed by mass spectrometry and associated with development of therapy resistance can thus support molecular diagnosis and provide a potential complementary cancer biomarker., (© 2018 John Wiley & Sons, Ltd.)

Coumarins show biological activity and are widely exploited for their therapeutic effects. Although a great number of coumarins substituted by heterocyclic moieties have been prepared, few studies have been carried out on coumarins containing pyridine heterocycle, which is known to modulate their physiological activities. We prepared and characterized three novel 3-(pyridin-2-yl)coumarins and their corresponding copper(II) complexes. We extended our investigations also to three known similar coumarins, since no data about their biochemical activity was previously been reported. The antiproliferative activity of the studied compounds was tested against human derived tumor cell lines and one human normal cell line. The DNA binding constants were determined and docking studies with DNA carried out. Selected Quantitative Structure-Activity Relationship (QSAR) descriptors were calculated in order to relate a set of structural and topological descriptors of the studied compounds to their DNA interaction and cytotoxic activity., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Malignant mesothelioma is a rare and aggressive form of cancer affecting the mesothelium. This mainly occupational disease is becoming more common in those countries where asbestos has been used for industrial applications. Notwithstanding the progress made in the field, patients do not survive more than 12 months on average with standard treatment. With the advent of next generation sequencing, it is now possible to study the mutational landscape of each tumor with the aim of identifying the genetic aberrations driving tumorigenesis. This review encompasses the latest research in the field, with particular attention to new chemotherapy combinatorial regimens, molecular targets and immunotherapies, providing a comprehensive picture of the current and future treatment options for malignant mesothelioma patients.

A large number of cancers are treated with cisplatin (CDDP). However, its use is limited by drug resistance, which is often related to intracellular levels of thiol-containing molecules such as glutathione (GSH). The role of GSH in cisplatin-resistant cancer cells is still unclear. GSH may form adducts with CDDP which results in the deactivation of the drug, and, actually, a high intracellular level of GSH was observed in some cisplatin-resistant cancers. To overcome drug resistance, CDDP is often administered in combination with one or more drugs to exploit a possible synergistic effect. In previous studies, we observed that the sensitivity to CDDP of leukemic and ovarian cisplatin-resistant cancer cells was restored in the presence of [Cu(phen) 2 (H 2 O)](ClO 4 ) 2 (C0) (phen is 1,10-phenathroline). In order to clarify the possible interactions between GSH and CDDP, the reactivity and competitive reactions among CDDP, C0 and GSH in binary and ternary mixtures were studied. The investigation was extended also to [Cu(phen)(H 2 O) 2 (ClO 4 ) 2 ] (C10) and GSSG, the oxidized form of GSH. It was observed that CDDP was able to react with the studied copper complexes and with GSH or GSSG. However, in mixtures containing CDDP, GSH or GSSG and C0 or C10, only copper-glutathione complexes were detected, while no platinum-glutathione adducts were found., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Cross-contamination of eukaryotic cell lines used in biomedical research represents a highly relevant problem. Analysis of repetitive DNA sequences, such as Short Tandem Repeats (STR), or Simple Sequence Repeats (SSR), is a widely accepted, simple, and commercially available technique to authenticate cell lines. However, it provides only qualitative information that depends on the extent of reference databases for interpretation. In this work, we developed and validated a rapid and routinely applicable method for evaluation of cell culture cross-contamination levels based on mass spectrometric fingerprints of intact mammalian cells coupled with artificial neural networks (ANNs). We used human embryonic stem cells (hESCs) contaminated by either mouse embryonic stem cells (mESCs) or mouse embryonic fibroblasts (MEFs) as a model. We determined the contamination level using a mass spectra database of known calibration mixtures that served as training input for an ANN. The ANN was then capable of correct quantification of the level of contamination of hESCs by mESCs or MEFs. We demonstrate that MS analysis, when linked to proper mathematical instruments, is a tangible tool for unraveling and quantifying heterogeneity in cell cultures. The analysis is applicable in routine scenarios for cell authentication and/or cell phenotyping in general.

Cisplatin, cis-diammineplatinum(II) dichloride, is a metal complex used in clinical practice for the treatment of cancer. Despite its great efficacy, it causes adverse reactions and most patients develop a resistance to cisplatin. To overcome these issues, a multi-drug therapy was introduced as a modern approach to exploit the drug synergy. A synergistic effect had been previously found when testing binary combinations of cisplatin and three copper complexes in vitro, namely, Cu(phen)(OH2)2(OClO3)2, [Cu(phen)2(OH2)](ClO4)2 and [Cu(phen)2(H2dit)](ClO4)2,(phen=1,10-phenanthroline, H2dit=imidazolidine-2-thione), against the human acute T-lymphoblastic leukaemia cell line (CCRF-CEM). In this work [Cu(phen)2(OH2)](ClO4)2 was also tested in combination with cisplatin against cisplatin-resistant sublines of CCRF-CEM (CCRF-CEM-res) and ovarian (A2780-res) cancer cell lines. The tested combinations show a synergistic effect against both the types of resistant cells. The possibility that this effect was caused by the formation of new adducts was considered and mass spectra of solutions containing cisplatin and one of the three copper complexes at a time were measured using electrospray ionisation at atmospheric-pressure mass spectrometry (ESI-MS). A mixed complex was detected and its stoichiometry was assessed on the basis of the isotopic pattern and the results of tandem mass spectrometry experiments. The formed complex was found to be [Cu(phen)(OH)μ-(Cl)2Pt(NH3)(H2O)](+)., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The speciation of the potential antitumor agent vanadocene dichloride ([Cp2VCl2], abbreviated with VDC) in the blood plasma was studied by instrumental (EPR, ESI-MS, MS-MS, and electronic absorption spectroscopy) and computational (DFT) methods. The behavior of VDC at pH 7.4 in aqueous solution, the interaction with the most important bioligands of the plasma (oxalate, carbonate, phosphate, lactate, citrate, histidine, and glycine among those with low molecular mass and transferrin and albumin between the proteins) was evaluated. The results suggest that [Cp2VCl2] transforms at physiological pH to [Cp2V(OH)2] and that only oxalate, carbonate, phosphate, and lactate are able to displace the two OH(-) ions to yield [Cp2V(ox)], [Cp2V(CO3)], [Cp2V(lactH(-1))], and [Cp2V(HPO4)]. The formation of the adducts with oxalate, carbonate, lactate, and hydrogen phosphate was confirmed also by ESI-MS and MS-MS spectra. The stability order is [Cp2V(ox)] ≫ [Cp2V(CO3)] > [Cp2V(lactH(-1))] > [Cp2V(HPO4)]. No interaction between VDC and plasma proteins was detected under our experimental conditions. Several model systems containing the bioligands (bL) in the same relative ratio as in the blood samples were also examined. Finally, the speciation of VDC in the plasma was studied. The results obtained show that the model systems behave as the blood plasma and indicate that when V concentration is low (10 μM) VDC is transported in the bloodstream as [Cp2V(ox)]; when V concentration is high (100 μM) oxalate binds only 9.2 μM of [Cp2V](2+), whereas the remaining part distributes between [Cp2V(CO3)] (main species) and [Cp2V(lactH(-1))] (minor species); and when V concentration is in the range 10-100 μM [Cp2V](2+) distributes between [Cp2V(ox)] and [Cp2V(CO3)].

The tetrahedral S-coordinated complex [Zn(MeImHS)4](ClO4)2, synthesised from the reaction of [Zn(ClO4)2] with methimazole (1-methyl-3H-imidazole-2-thione, MeImHS), reacts with triethylamine to yield the homoleptic complex [Zn(MeImS)2] (MeImS = anion methimazole). ESI-MS and MAS (13)C-NMR experiments supported MeImS acting as a (N,S)-chelating ligand. The DFT-optimised structure of [Zn(MeImS)2] is also reported and the main bond lengths compared to those of related Zn-methimazole complexes. The complex [Zn(MeImS)2] reacts under mild conditions with methyl iodide and separates the novel complex [Zn(MeImSMe)2I2] (MeImSMe = S-methylmethimazole). X-ray diffraction analysis of the complex shows a ZnI2N2 core, with the methyl thioethers uncoordinated to zinc. Conversely, the reaction of [Zn(MeImS)2] with hydroiodic acid led to the formation of the complex [Zn(MeImHS)2I2] having a ZnI2S2 core with the neutral methimazole units S-coordinating the metal centre. The Zn-coordinated methimazole can markedly modify the coordination environment when changing from its thione to thionate form and vice versa. The study of the interaction of the drug methimazole with the complex [Zn(MeIm)4](2+) (MeIm = 1-methylimidazole) - as a model for Zn-enzymes containing a N4 donor set from histidine residues - shows that methimazole displaces only one of the coordinated MeIm molecules; the formation constant of the mixed complex [Zn(MeIm)3(MeImHS)](2+) was determined.

The cytotoxic properties of copper(II) complexes with 1,10-phenanthroline (phen) can be modified by substitution in the phen backbone. For this purpose, Cu(II) complexes with phen, 1,10-phenanthrolin-5,6-dione (phendione) and 1,10-phenanthrolin-5,6-diol (phendiol) have been synthesised and characterised. The crystal structure of [Cu(phendione)2(OH2)(OClO3)](ClO4) is discussed. The complex formation equilibria between Cu(II) and phen or phendione were studied by potentiometric measurements at 25 and 37°C in 0.1 M ionic strength (NaCl). The antitumour activity of the compounds has been tested in vitro against a panel of tumour (DU-145, HEP-G2, SK-MES-1, CCRF-CEM, CCRF-SB) and normal (CRL-7065) human cell lines. The studied compounds generally present an antiproliferative effect greater than that of cisplatin. The phen and phendione ligands present a similar antiproliferative effect against all the tested cells. Phendiol presents an antiproliferative effect 1.3 to 18 times greater than that of phen or phendione for leukemic, lung, prostatic and fibroblast cells, while it presents less activity towards hepatic cells. Complexes with two ligands are more cytotoxic towards all the tested cell lines than complexes with one ligand and are generally more cytotoxic than the ligand alone. Complexes [Cu(phendiol)2(OH2)](ClO4)2 and [Cu(phendione)2(OH2)(OClO3)](ClO4) appear to be the most active compounds for the treatment of SK-MES-1 and HEP-G2 cells, respectively, being at least 18 times more cytotoxic than cisplatin. The studied Cu(II) complexes are characterised by a strong DNA affinity and were found to interact with DNA mainly by groove binding or electrostatic interactions. The complexes appear to act on cells with a mechanism different from that of cisplatin., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The combination of two or more drugs using multidrug mixtures is a trend in the treatment of cancer. The goal is to search for a synergistic effect and thereby reduce the required dose and inhibit the development of resistance. An advanced model-free approach for data exploration and analysis, based on artificial neural networks (ANN) and experimental design is proposed to predict and quantify the synergism of drugs. The proposed method non-linearly correlates the concentrations of drugs with the cytotoxicity of the mixture, providing the possibility of choosing the optimal drug combination that gives the maximum synergism. The use of ANN allows for the prediction of the cytotoxicity of each combination of drugs in the chosen concentration interval. The method was validated by preparing and experimentally testing the combinations with the predicted highest synergistic effect. In all cases, the data predicted by the network were experimentally confirmed. The method was applied to several binary mixtures of cisplatin and [Cu(1,10-orthophenanthroline)2(H2O)](ClO4)2, Cu(1,10-orthophenanthroline)(H2O)2(ClO4)2 or [Cu(1,10-orthophenanthroline)2(imidazolidine-2-thione)](ClO4)2. The cytotoxicity of the two drugs, alone and in combination, was determined against human acute T-lymphoblastic leukemia cells (CCRF-CEM). For all systems, a synergistic effect was found for selected combinations., (© 2013 Elsevier B.V. All rights reserved.)

Cu(II) complexes with 1,10-orthophenanthroline (phen) show cytotoxic and antitumoral effects. To enhance and exploit these features, we studied complexes containing one or two phen units together with N,N'-substituted-imidazolidine-2-thione (L). We synthesized and structurally characterized the precursor molecule Cu(phen)(OH(2))(2)(OClO(3))(2), and determined the complex formation constants of [Cu(phen)(L)](2+). We studied the cytotoxic activity of [Cu(phen)(2)(L)](ClO(4))(2) versus human hematologic (CCRF-CEM and CCRF-SB) and solid tumor-derived cell lines (K-MES-1, DU-145). The cytotoxic activities, in the 1-3 μM range, show that our Cu(II)-complexes possess comparable inhibitory activities against both leukemia and carcinoma cells, unlike the majority of antineoplastic agents, usually more potent against hematologic cancer cells than against solid tumor cells. Because the free Cu(II) ion is reduced by glutathione (GSH), we studied the reactivity of our complexes with GSH, providing evidence that no redox reaction occurred under the chosen experimental conditions. Complex formation equilibria were present, studied by spectrophotometric titrations. The redox properties of the prepared compounds were also investigated by cyclic voltammetry, confirming that the mixed Cu(II) complexes were resistant to reduction., (Copyright © 2012 Elsevier Inc. All rights reserved.)

The synthesis, crystal structures, physicochemical properties and complex formation constants of [Cu(phen)(2)(L)](ClO(4))(2) complexes, where phen is 1,10-ortho-phenanthroline and L is a series of substituted imidazolidine-2-thione, have been studied. Single crystal X-ray diffraction revealed a distorted trigonal-bipyramidal geometry for all the molecules. The complex formation constants were determined in nonaqueous media by spectrophotometric measurements. Testing copper(II) complexes in mouse neuroblastoma N2a cells persistently infected with the 22L strain of the scrapie prion protein (22L-N2a) resulted in high cytotoxicity but no antiprion activity at nontoxic doses., (Copyright © 2010 Elsevier Inc. All rights reserved.)

With the aim to design new chelators for the clinical treatment of different diseases involving the trivalent metal ions Fe(III) and Al(III), we present the equilibria of kojic acid and its derivative 6-[5-hydroxy-2-hydroxymethyl-pyran-4-one]-5-hydroxy-2-hydroxymethyl-pyran-4-one with these two metal ions. Potentiometric and spectrophotometric techniques for iron, and potentiometry and (1)H NMR for aluminum were used, supported by X-ray, electrospray ionization-mass spectrometry (ESI-MS), calorimetry and quantum chemical calculations. In this work, evidence is given on the formation of MeL, MeL(2), and MeL(3) complexes of both metal ions with kojic acid, confirmed by the X-ray structure of the FeL(3) complex, and of variously protonated Me(2)L(2) and MeL(2) complexes of 6-[5-hydroxy-2-hydroxymethyl-pyran-4-one]-5-hydroxy-2-hydroxymethyl-pyran-4-one. The extremely good pFe value for this second ligand gives confidence to, and opens perspectives for, the search of new kojic acid derivatives.

The solution equilibria of iron(III) and aluminum(III) with two classes of hard ligands (catechol, salicylic acid and their nitro-derivatives) have been reliably studied by potentiometric, spectrophotometric and NMR spectroscopy. The effect of the nitro substituent on the binding properties of catechol and salicylic acid has been examined thoroughly. The inductive and resonance properties of the substituent that, as expected, lower the basicity of the phenolic and carboxylic groups, lead to a general decrease in both protonation and complex formation constants. This decrease causes an increase in pM of between 0.2 and 1.1pM units for the nitro-substituted salicylates and of about 4 units for 4-nitrocatechol, with a significantly higher chelating efficacy. The influence of the substituent on catechol and salicylic acid is discussed in detail on the basis of conditional constants at pH 7.4.

Stems, leaves, buds and flowers of Laurus nobilis L. growing wild in Tunisia were analysed for their essential oil composition. The essential oil of Laurus nobilis L. gathered from different stations were isolated by hydrodistillation and analysed by GC/MS. The oil yields on a dry weight basis ranged between 0.4% and 1.1%. The major component identified was 1,8-cineole, other predominant components were alpha-terpinyl acetate, methyl eugenol, eugenol and linalool. Although the same compounds were present in all plant organs, the leaves differed from the stems in the concentration of 1,8-cineole and methyl eugenol, buds and flowers in the concentration of 1,8-cineole and the stem's oil composition differs from the others in content of methyl eugenol. The results obtained from GC/MS analysis of the volatile oils from individual plant organs were submitted to principal component analysis. Chemometric investigations led to differentiation of stems, leaves and buds-flowers with the respect to the content of 1,8-cineole, metyhyl eugenol and alpha-terpynil acetate; flowers and buds were non-differentiated. Finally, the antibacterial activity of the leaves' essential oils has been assayed.

Coordination properties toward Fe(III) and Al(III) of a mixed bisphosphonate-hydroxypyridinonate ligand are presented. Potentiometric, spectrophotometric and NMR results allowed to conclude that Fe(III) and Al(III) coordination takes place on the pyridinone moiety. The high steric hindrance prevents the possibility of simultaneous coordination of both groups to the same metal ion. Quantum mechanical calculations confirm this finding allowing to determine the minimal length of the linker necessary for a stable conformation of complexes in which Fe(III) is coordinated both by pyridinone and bisphosphonate groups.

The iron(III)-1,2-dimethyl-3-hydroxy-4-pyridinone (Deferiprone) system is carefully characterized by a combined potentiometric-spectrophotometric procedure at 25 and 37 degrees C at different ionic strengths, and by thermochemical and quantum-chemical studies. The main purpose of this work was to determine how the temperature dependence of both complex-formation and protonation constants can affect the pFe values on going from 25 degrees C (pFe is normally calculated using 25 degrees C stability constants) to the physiological temperature of 37 degrees C at which chelating agents are active in vivo. The copper(II)-Deferiprone system is also studied and the iron(III)-Deferiprone distribution diagrams in presence of variable copper(II) amounts are shown so as to explain possible side effects due to a competing metal ion during the chelating therapy of iron overload.

The coordination properties of mixed catechol-bisphosphonates towards Fe(III) are presented. From the potentiometric and spectroscopic results it was possible to state that iron coordination takes place only on the bisphosphonate moiety at acidic pH, and involves both catechol and bisphosphonate groups on two different iron(III) ions at higher pH values. Steric constracts keep both groups from chelating the same metal ion. Quantum mechanical calculations confirm this statement and allow to determine the minimum length of the linker for a stable conformation of complexes in which the same iron(III) ion is coordinated by both catechol and bisphosphonate.

In the first title salt, [Cu(C(12)H(8)N(2))(2)(C(5)H(10)N(2)Se)](ClO(4))(2), the Cu(II) centre occupies a distorted trigonal-bipyramidal environment defined by four N donors from two 1,10-phenanthroline (phen) ligands and by the Se donor of a 1,3-dimethylimidazolidine-2-selone ligand, with the equatorial plane defined by the Se and by two N donors from different phen ligands and the axial sites occupied by the two remaining N donors, one from each phen ligand. The Cu-N distances span the range 1.980 (10)-2.114 (11) A and the Cu-Se distance is 2.491 (3) A. Intermolecular pi-pi contacts between imidazolidine rings and the central rings of phen ligands generate chains of cations. In the second salt, [Cu(C(10)H(8)N(2))(2)(C(3)H(6)N(2)S)](ClO(4))(2), the Cu(II) centre occupies a similar distorted trigonal-bipyramidal environment comprising four N donors from two 2,2'-bipyridyl (bipy) ligands and an S donor from an imidazolidine-2-thione ligand. The equatorial plane is defined by the S donor and two N donors from different bipy ligands. The Cu-N distances span the range 1.984 (6)-2.069 (7) A and the Cu-S distance is 2.366 (3) A. Intermolecular pi-pi contacts between imidazolidine and pyridyl rings form chains of cations. A major difference between the two structures is due to the presence in the second complex of two N-H...O hydrogen bonds linking the imidazolidine N-H hydrogen-bond donors to perchlorate O-atom acceptors.

The windmill-shaped hexanuclear copper(II) cluster {(H(2)O)(2)Cu(2)(mu(3)-(Ade)(4)[Cu(oda)(H(2)O)](4)}.6H(2)O (1-o) has been synthesized in aqueous medium by in situ core-controlled expansion of the neutral building block Cu(2)(mu(2)-N3,N9-Ade)(4)(H(2)O)(2) (2) with Cu(oda)(H(2)O) (3-o) (Ade = adeninato(1-) and oda = oxydiacetato(2-) ligands). Crystal data for 2-b (2.5H(2)O): triclinic, space group P(-)1; a = 9.374(1), b = 9.440(1), c = 10.326(1) A; alpha = 78.72(1), beta = 76.77(1), gamma = 63.51(1) degrees ; final R(1) = 0.059; T = 100(2) K. Crystal data for 1-o: monoclinic, space group P2(1)/n; a = 15.203(2), b = 10.245(1), c = 19.094(2) A; beta = 101.61(1) degrees ; final R(1) = 0.049; T = 293(2) K. The X-shaped hexanuclear molecule consists of a central core (2) and four terminal arms (3-o) linked together by bridging mu(3)-N3,N7,N9-Ade ligands. There are three crystallographic independent metal atoms (two terminals, one central). All Cu(II) atoms exhibit a 4 + 1 coordination, of which one is an aqua apical ligand. The basal coordination sets complete the CuN(4) + O or CuO(3)N + O chromophores for the central or terminal metal atoms, respectively. Thermal stability and spectral and magnetic properties were also studied. Analogous compounds to 1-o with tridentate or tripodal tetradentate ligands L(2-), instead of oda, have also been synthesized.

The use of a fibre optic device for spectrophotometric measurements in solution equilibria studies is presented. In particular the precision obtainable with such equipment is evaluated as a function of different experimental conditions, such as path length, averaging time and stirring of the solution. Analysis of 3-hydroxybenzoic acid ionization is presented to assess the results obtained in the study of an equilibrium system.

The pK(a) values of ionisation of a set of phenols ortho, meta and para substituted are studied by spectrophotometry and (13)C NMR spectroscopy. A dual substituent analysis of equilibrium and NMR results, according to the Swain and Lupton procedure, is presented. The results of this analysis allow the assignment of the contribution of field and resonance contributions, both on equilibrium constants and chemical shifts.