Redox-Active Bis-Cyclometalated Iridium(III) Complex as a DNA Photo-Cleaving Agent.

The development of new photoactive metal complexes that can trigger oxidative damages to the genetic material is of great interest. In the present paper, we describe the detailed study of a highly photo-oxidant iridium(III) complex that triggers photoinduced electron transfer (PET) with purine DNA bases. The PET has been studied by luminescence and laser flash photolysis experiments. From plasmid DNA agarose gel electrophoresis experiments, we demonstrated the high ability of the iridium complex to induce strand breaks upon light irradiation. Reactive oxygen species (ROS)-specific scavengers and stabilizers were employed to identify that the photocleavage process, the results of which infer singlet oxygen and hydrogen peroxide as the predominant species. To the best of our knowledge, the present work represents one of the few study for highly photo-oxidant bis-cyclometalated iridium(III) complex toward DNA.

The animal cachexia score (ACASCO).

BACKGROUND: None of the published studies involving cancer cachexia experimental models have included a measure of the severity of the syndrome like the scoring system previously developed for human subjects. The aim of the present investigation was to define and validate a cachexia score usable in both rat and mouse tumor models. METHODS: In order to achieve this goal, we included in the study one rat model (Yoshida AH-130ascites hepatoma) and two mouse models (Lewis lung carcinoma and Colon26 carcinoma). The Animal cachexia score (ACASCO) includes five components: (a) body and muscle weight loss, (b) inflammation and metabolic disturbances, (c) physical performance, (d) anorexia, and (e) quality of life measured using discomfort symptoms and behavioral tests. RESULTS: Using the ACASCO values, three cut-off values were estimated by applying hierarchical cluster analysis. Four groups were originally described, one exactly below the observed mean, a second exactly over the mean, and two other groups adjusted to every cue (inferior and superior). The three cut-off values were estimated through maximization of the classification function. This was accomplished by using a similarity matrix based on the metric properties of the variables and assuming multinormal distribution. The results show that the four groups were: no cachexia, mild cachexia, moderate cachexia and advanced cachexia. CONCLUSIONS: The results obtained allow us to conclude that the score could be very useful as an endpoint in pre-clinical studies involving therapeutic strategies for cancer cachexia. The potential usefulness of ACASCO relates to the primary endpoint in pre-clinical cancer cachexia drug evaluations.

New Acridine-Based Tridentate Ligand for Ruthenium(II): Coordination with a Twist.

A new tridentate ligand based on acridine has been synthetized. The central acridine heterocycle bears two pyridine coordinating units at positions 4 and 5. The terdentate 2,7-di- tert-butyl-4,5-di(pyridin-2-yl)acridine (dtdpa) was then coordinated to a ruthenium(II) cation. The corresponding homoleptic complex could only be obtained where both ligands coordinate to the ruthenium in a fac fashion. Thus, a heteroleptic compound (2) was constructed in combination with a terpyridine ligand in order to constrain the ligand to adopt a mer geometry. Such a coordination imposes a dramatic twist on the acridine heterocycle, resulting in an unexpected photophysical behavior. The electrochemical and photophysical properties of both complexes were studied, and the molecular structure of 2 was determined by X-ray diffraction. The two compounds absorb at low energy wavelengths, and a very weak luminescence is detected only for complex 2 in the near-infrared region.

Preparation and Properties of Chlorosulfuryl Chloroformate, ClC(O)OSO2Cl.

The novel chlorosulfuryl chloroformate, ClC(O)OSO2Cl, was prepared by the reaction of CCl4 and SO3. Alternatively, the compound was obtained from the direct insertion reaction of SO3 to Cl2C═O. The latter reaction constitutes also a confirmation of the proposed mechanism for the former one. Density functional theory and MP2 theoretical approximations predict the existence of two conformers, syn-gauche and syn-anti, depending on the value adopted by the dihedral angles ϕ(Cl-C-O-S) and ϕ(C-O-S-Cl). The structure of the syn-gauche conformer was determined by gas-phase electron diffraction (GED). The existence of the syn-anti conformer can be neither confirmed nor excluded by the GED experiment. Vibrational spectra (vapor-phase and argon-matrix Fourier transform infrared and liquid Fourier transform Raman) were interpreted by an equilibrium mixture between both conformers.

Ultrafast charge transfer excited state dynamics in trifluoromethyl-substituted iridium(iii) complexes.

Time-resolved spectroscopy was exploited to gain new insights into the nature and dynamics of charge transfer excited states of bis-cyclometalated Ir(iii) complexes. We showed that its dynamics is strongly influenced by the nature of the diimine ligand due to the existence of a ligand-ligand charge transfer process in the picosecond timescale. All the results are supported by DFT/TD-DFT calculations and spectroelectrochemistry.

Disulfuryl Dichloride ClSO2 OSO2 Cl: A Conformation and Polymorphism Chameleon.

Disulfuryl dichloride ClSO2 OSO2 Cl was characterized by vibrational spectroscopy in the gaseous and liquid phase as well as in the Ar-matrix. By varying the temperature, certain bands could be assigned to several conformers. Gas-phase electron diffraction revealed a dominance of the anti-conformer at ambient temperature. The same conformation was found in the solid state. Via the in situ technique for crystallization, not less than four different modifications were identified. Among these different modifications, the structural parameters of the molecules remain relatively constant, but the aggregation pattern changes. Although the molecules aggregate by chlorine⋅⋅⋅oxygen contacts in each modification, the geometrical parameters of these interaction show significant differences and were evaluated and are in part inconsistent with the halogen bonding concept.

Validation of the CAchexia SCOre (CASCO). Staging Cancer Patients: The Use of miniCASCO as a Simplified Tool.

The CAchexia SCOre (CASCO) was described as a tool for the staging of cachectic cancer patients. The aim of this study is to show the metric properties of CASCO in order to classify cachectic cancer patients into three different groups, which are associated with a numerical scoring. The final aim was to clinically validate CASCO for its use in the classification of cachectic cancer patients in clinical practice. We carried out a case -control study that enrolled prospectively 186 cancer patients and 95 age-matched controls. The score includes five components: (1) body weight loss and composition, (2) inflammation/metabolic disturbances/immunosuppression, (3) physical performance, (4) anorexia, and (5) quality of life. The present study provides clinical validation for the use of the score. In order to show the metric properties of CASCO, three different groups of cachectic cancer patients were established according to the results obtained with the statistical approach used: mild cachexia (15 ≤ × ≤ 28), moderate cachexia (29 ≤ × ≤ 46), and severe cachexia (47 ≤ × ≤ 100). In addition, a simplified version of CASCO, MiniCASCO (MCASCO), was also presented and it contributes as a valid and easy-to-use tool for cachexia staging. Significant statistically correlations were found between CASCO and other validated indexes such as Eastern Cooperative Oncology Group (ECOG) and the subjective diagnosis of cachexia by specialized oncologists. A very significant estimated correlation between CASCO and MCASCO was found that suggests that MCASCO might constitute an easy and valid tool for the staging of the cachectic cancer patients. CASCO and MCASCO provide a new tool for the quantitative staging of cachectic cancer patients with a clear advantage over previous classifications.

A multifactorial anti-cachectic approach for cancer cachexia in a rat model undergoing chemotherapy.

BACKGROUND: The effectiveness of drugs aimed at counteracting cancer cachexia is generally tested in pre-clinical rodent models, where only the tumour-induced alterations are taken into account, excluding the co-presence of anti-tumour molecules that could worsen the scenario and/or interfere with the treatment. METHODS: The aim of the present investigation has been to assess the efficacy of a multifactorial treatment, including formoterol and megestrol acetate, in cachectic tumour-bearing rats (Yoshida AH-130, a highly cachectic tumour) undergoing chemotherapy (sorafenib). RESULTS: Treatment of cachectic tumour-bearing rats with sorafenib (90 mg/kg) causes an important decrease in tumour cell content due to both reduced cell proliferation and increased apoptosis. As a consequence, animal survival significantly improves, while cachexia occurrence persists. Multi-factorial treatment using both formoterol and megestrol acetate is highly effective in preventing muscle wasting and has more powerful effects than the single formoterol administration. In addition, both physical activity and grip strength are significantly improved as compared with the untreated tumour-bearing animals. The effects of the multi-factorial treatment include increased food intake (likely due to megestrol acetate) and decreased protein degradation, as shown by the reduced expression of genes associated with both proteasome and calpain proteolytic systems. CONCLUSIONS: The combination of the two drugs proved to be a promising strategy for treating cancer cachexia in a pre-clinical setting that better resembles the human condition, thus providing a strong rationale for the use of such combination in clinical trials involving cachectic cancer patients.

Complete reversal of muscle wasting in experimental cancer cachexia: Additive effects of activin type II receptor inhibition and ß-2 agonist.

Formoterol is a highly potent ß2-adrenoceptor-selective agonist, which is a muscle growth promoter in many animal species. Myostatin/activin inhibition reverses skeletal muscle loss and prolongs survival of tumor-bearing animals. The aim of this investigation was to evaluate the effects of a combination of the soluble myostatin receptor ActRIIB (sActRIIB) and the ß2-agonist formoterol in the cachectic Lewis lung carcinoma model. The combination of formoterol and sActRIIB was extremely effective in reversing muscle wasting associated with experimental cancer cachexia in mice. Muscle weights from tumor-bearing animals were completely recovered following treatment and this was also reflected in the measured grip strength. This combination increased food intake in both control and tumor-bearing animals. The double treatment also prolonged survival significantly without affecting the weight and growth of the primary tumor. In addition, it significantly reduced the number of metastasis. Concerning the mechanisms for the preservation of muscle mass during cachexia, the effects of formoterol and sActRIIB seemed to be additive, since formoterol reduced the rate of protein degradation (as measured in vitro as tyrosine release, using incubated isolated individual muscles) while sActRIIB only affected protein synthesis (as measured in vivo using tritiated phenylalanine). Formoterol also increased the rate of protein synthesis and this seemed to be favored by the presence of sActRIIB. Combining formoterol and sActRIIB seemed to be a very promising treatment for experimental cancer cachexia. Further studies in human patients are necessary and may lead to a highly effective treatment option for muscle wasting associated with cancer.

Photofragmentation Mechanisms of Chlorosulfonyl Isocyanate, ClSO2NCO, Excited with Synchrotron Radiation between 12 and 550 eV.

The unimolecular photofragmentation mechanisms of chlorosulfonyl isocyanate, ClSO2NCO, excited with tunable synchrotron radiation between 12 and 550 eV, were investigated by means of time-of-flight (TOF) coincidence techniques. The main fragmentation mechanism after single ionization, produced by irradiation of an effusive beam of the sample with synchrotron light in the valence electron region, occurs through the breaking of the Cl-S single bond, giving a chloride radical and a SO2NCO(+) fragment. This mechanism contrasts with the one observed for the related FSO2NCO, in which the rupture of the S-N bond originates the FSO2(+) fragment. The energies of the shallow- (S 2p, Cl 2p, and S 2s) and core-shell (C 1s, N 1s, and O 1s) electrons were determined by X-ray absorption. Transitions between these shallow and core electrons to unoccupied molecular orbitals were also observed in the total ion yield (TIY) spectra. Fourteen different fragmentation mechanisms of the doubly charged parent ion, ClSO2NCO(2+), were inferred from the bidimensional photoelectron-photoion-photoion-coincidence (PEPIPICO) spectra. The rupture of the S-N bond can evolve to form NCO(+)/SO2(•+), NCO(+)/SO(•+), or S(•+)/NCO(+) pairs of ions. The Cl-S bond breaking originates different mechanisms, Cl(+)/SO(•+), Cl(+)/S(•+), CO(•+)/S(•+), O(•+)/SO(•+), O(•+)/Cl(+), O(•+)/S(•+), C(•+)/S(•+), and C(•+)/O(•+) pairs being detected in coincidence as the final species. Another three coincidence islands can only be explained with an initial atomic rearrangement forming ClNCO(2+), ONCO(2+), and ClCO(2+), as precursors of CO(•+)/Cl(+), O(•+)/CO(•+), and C(•+)/Cl(+) pairs, respectively. The formation of Cl(•) radical is deduced from several mechanisms.

Ionic fragmentation mechanisms of 2,2,2-trifluoroethanol following excitation with synchrotron radiation.

Gaseous 2,2,2-trifluoroethanol (TFE) is excited with synchrotron radiation between 10 and 1000 eV and the ejected electrons and positive ions are detected in coincidence. In the valence-electron energy region, the most abundant species is CH2 OH(+) . Other fragments, including ions produced by atomic rearrangements, are also detected; the most abundant are COH(+) , CFH2 (+) and CF2 H2 (+) . The energies of electronic transitions from C 1 s, O 1 s and F 1 s orbitals to vacant molecular orbitals are determined. A site-specific C 1 s excitation is observed. The photofragmentation mechanisms after the excitation of core-shell electrons are inferred from analysis of the shape and slope of the coincidence between two charged fragments in the bi-dimensional coincidence spectra. The spectra are dominated by islands that correspond to the coincidence of H(+) with several charged fragments. One of the most important channels leads to the formation of CH2 OH(+) and CF3 (+) in a concerted mechanism.

Electronic properties of fluorosulfonyl isocyanate, FSO2NCO: a photoelectron spectroscopy and synchrotron photoionization study.

The electronic properties of fluorosulfonyl isocyanate, FSO2NCO, were investigated by means of photoelectron spectroscopy and synchrotron based techniques. The first ionization potential occurs at 12.3 eV and was attributed to the ejection of electrons formally located at the π NCO molecular orbital (MO), with a contribution from nonbonding orbitals at the oxygen atoms of the SO2 group. The proposed interpretation of the photoelectron spectrum is consistent with related molecules reported previously and also with the prediction of OVGF (outer valence green function) and P3 (partial third order) calculations. The energy of the inner- and core-shell electrons was determined using X-ray absorption, measuring the total ion yield spectra, and the resonances before each ionization threshold were interpreted in terms of transitions to vacant molecular orbitals. The ionic fragmentation mechanisms in the valence energy region were studied using time-of-flight mass spectrometry as a function of the energy of the incident radiation. At 13 eV the M(+) was the only ion detected in the photoion-photoelectron-coincidence spectrum, while the FSO2(+) fragment, formed through the breaking of the S-N single bond, appears as the most intense fragment for energies higher than 15 eV. The photoion-photoion-photoelectron-coincidence spectra, taken at the inner- and core-levels energy regions, revealed several different fragmentation pathways, being the most important ones secondary decay after deferred charge separation mechanisms leading to the formation of the O(+)/S(+) and C(+)/O(+) pairs.

Formoterol treatment downregulates the myostatin system in skeletal muscle of cachectic tumour-bearing rats.

Cachexia is a common systemic manifestation. Additionally, myostatin is known to be a negative regulator of skeletal muscle development. The present study aimed to investigate whether formoterol down-regulates the myostatin system in skeletal muscle of tumour-bearing rats. Real-time PCR and Western blotting were used for the analysis. Results showed that rats bearing the Yoshida AH-130 ascites hepatoma, a cachexia-inducing tumour, exhibited marked muscle wasting that affected the mass of the muscles studied. The cachectic animals exhibited a significant increase in the mRNA levels of the myostatin receptor (ActIIB) in gastrocnemius muscles. Notably, the expression of the various forms of follistatin, a protein with the opposite effects to those of myostatin, was significantly reduced as a result of the implantation of the tumour. When the animals were treated with formoterol, a ß-agonist with anti-cachectic potential, increases in skeletal muscle weights were observed. The ß-agonist significantly increased levels of various follistatin isoforms and significantly decreased the expression levels of the myostatin receptor. In addition, formoterol treatment resulted in a significant decrease of the myostatin protein content of the gastrocnemius muscle. In conclusion, the results presented indicate that certain anabolic actions of formoterol on the skeletal muscle of cachectic animals may be mediated via the myostatin system.

L-Carnitine: an adequate supplement for a multi-targeted anti-wasting therapy in cancer.

BACKGROUND & AIMS: Tumour growth is associated with weight loss resulting from both adipose and muscle wasting. METHODS: Administration of L-carnitine (1 g/kg body weight) to rats bearing the AH-130 Yoshida ascites hepatoma, a highly cachectic rat tumour. RESULTS: The treatment results in a significant improvement of food intake and in muscle weight (gastrocnemius, EDL and soleus). These beneficial effects are directly related to improved physical performance (total physical activity, mean movement velocity and total travelled distance). Administration of L-carnitine decreases proteasome activity and the expression of genes related with this activity, such as ubiquitin, C8 proteasome subunit and MuRF-1. Interestingly, L-carnitine treatment also decreases caspase-3 mRNA content therefore suggesting a modulation of apoptosis. Moreover, addition of 50 µM of L-carnitine to isolated EDL muscles results in a significant decrease in the proteolytic rate suggesting a direct effect. CONCLUSIONS: It can be concluded that L-carnitine supplementation may be a good approach for a multi-targeted therapy for the treatment of cancer-related cachexia.

The cachexia score (CASCO): a new tool for staging cachectic cancer patients.

BACKGROUND: According to a recent consensus, the cachectic syndrome is defined as: "… a complex metabolic syndrome associated with underlying illness and characterized by loss of muscle with or without loss of fat mass. The prominent clinical feature of cachexia is weight loss in adults (corrected for fluid retention) or growth failure in children (excluding endocrine disorders). Anorexia, inflammation, insulin resistance, and increased muscle protein breakdown are frequently associated with cachexia." Although this definition is accompanied by diagnostic criteria, it does not consider the problem of staging. Stratification of patients is important when considering therapy. The very first stage of the wasting syndrome does not necessarily involve body weight loss-a state known as pre-cachexia. METHODS AND RESULTS: The aim of the present score was to overcome the problem of patient staging in cancer. This score considers five main different factors: body weight and lean body mass loss; anorexia; inflammatory, immunological, and metabolic disturbances; physical performance; and quality of life. The scoring scale goes from 0 to 100: mild cachexia (less than 25), moderate (more than 26 and less than 50), severe (more than 51 and less than 75), and terminal phase (more than 76 and up to 100). The score also takes into consideration the condition known as pre-cachexia. CONCLUSION: The present score will facilitate cachexia staging and will therefore allow for a more adequate therapy. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13539-011-0027-5) contains supplementary material, which is available to authorized users.