The Changes of Lipid Metabolism in Advanced Renal Cell Carcinoma Patients Treated with Everolimus: A New Pharmacodynamic Marker?

Background

Everolimus is a mammalian target of rapamycin (mTOR) inhibitor approved for the treatment of metastatic renal cell carcinoma (mRCC). We aimed to assess the association between the baseline values and treatmentrelated modifications of total serum cholesterol (C), triglycerides (T), body mass index (BMI), fasting blood glucose level (FBG) and blood pressure (BP) levels and the outcome of patients treated with everolimus for mRCC.

Methods

177 patients were included in this retrospective analysis. Time to progression (TTP), clinical benefit (CB) and overall survival (OS) were evaluated.

Results

Basal BMI was significantly higher in patients who experienced a CB (p=0,0145). C,T and C+T raises were significantly associated with baseline BMI (p=0.0412, 0.0283 and 0.0001). Median TTP was significantly longer in patients with T raise compared to patients without T (10 vs 6, p=0.030), C (8 vs 5, p=0.042) and C+T raise (10.9 vs 5.0, p=0.003). At the multivariate analysis, only C+T increase was associated with improved TTP (p=0.005). T raise (21.0 vs 14.0, p=0.002) and C+T increase (21.0 vs 14.0, p=0.006) were correlated with improved OS but were not significant at multivariate analysis.

Conclusion

C+T raise is an early predictor for everolimus efficacy for patients with mRCC.     

Crucial aminoacids in the FO sector of the F1FO-ATP synthase address H+ across the inner mitochondrial membrane: molecular implications in mitochondrial dysfunctions

Amino Acids - The eukaryotic F1FO-ATP synthase/hydrolase activity is coupled to H+ translocation through the inner mitochondrial membrane. According to a recent model, two asymmetric H+...     

Perturbation of cytochrome P450, generation of oxidative stress and induction of DNA damage in Cyprinus carpio exposed in situ to potable surface water

Epidemiological evidence suggests a link between consumption of chlorinated drinking water and various cancers. Chlorination of water rich in organic chemicals produces carcinogenic organochlorine by-products (OBPs) such as trihalomethanes and haloacetic acids. Since the discovery of the first OBP in the 1970s, there have been several investigations designed to determine the biological effects of single chemicals or small artificial OBP combinations. However, there is still insufficient information regarding the general biological response to these compounds, and further studies are still needed to evaluate their potential genotoxic effects. In the current study, we evaluated the effect of three drinking water disinfectants on the activity of cytochrome P450 (CYP)-linked metabolizing enzymes and on the generation of oxidative stress in the livers of male and female Cyprinus carpio fish (carp). The fish were exposed in situ for up 20 days to surface water obtained from the Trasmene lake in Italy. The water was treated with 1-2 mg/L of either sodium hypochlorite (NaClO) or chlorine dioxide (ClO2) as traditional disinfectants or with a relatively new disinfectant product, peracetic acid (PAA). Micronucleus (MN) frequencies in circulating erythrocytes from the fish were also analysed as a biomarker of genotoxic effect. In the CYP-linked enzyme assays, a significant induction (up to a 57-fold increase in the deethylation of ethoxyresorufin with PAA treatment) and a notable inactivation (up to almost a 90% loss in hydroxylation of p-nitrophenol with all disinfectants, and of testosterone 2beta-hydroxylation with NaClO) was observed in subcellular liver preparations from exposed fish. Using the electron paramagnetic resonance (EPR) spectroscopy radical-probe technique, we also observed that CYP-modulation was associated with the production of reactive oxygen species (ROS). In addition, we found a significant increase in MN frequency in circulating erythrocytes after 10 days of exposure of fish to water treated with ClO2, while a non-significant six-fold increase in MN frequency was observed with NaClO, but not with PAA. Our data suggest that the use of ClO2 and NaClO to disinfect drinking water could generate harmful OBP mixtures that are able to perturb CYP-mediated reactions, generate oxidative stress and induce genetic damage. These data may provide a mechanistic explanation for epidemiological studies linking consumption of chlorinated drinking water to increased risk of urinary, gastrointestinal and bladder cancers.     

The renewal and differentiation of Isl1+ cardiovascular progenitors are controlled by a Wnt/beta-catenin pathway

Isl1(+) cardiovascular progenitors and their downstream progeny play a pivotal role in cardiogenesis and lineage diversification of the heart. The mechanisms that control their renewal and differentiation are largely unknown. Herein, we show that the Wnt/beta-catenin pathway is a major component by which cardiac mesenchymal cells modulate the prespecification, renewal, and differentiation of isl1(+) cardiovascular progenitors. This microenvironment can be reconstituted by a Wnt3a-secreting feeder layer with ES cell-derived, embryonic, and postnatal isl1(+) cardiovascular progenitors. In vivo activation of beta-catenin signaling in isl1(+) progenitors of the secondary heart field leads to their massive accumulation, inhibition of differentiation, and outflow tract (OFT) morphogenic defects. In addition, the mitosis rate in OFT myocytes is significantly reduced following beta-catenin deletion in isl1(+) precursors. Agents that manipulate Wnt signals can markedly expand isl1(+) progenitors from human neonatal hearts, a key advance toward the cloning of human isl1(+) heart progenitors.     

CD8+ CD28- T regulatory lymphocytes inhibiting T cell proliferative and cytotoxic functions infiltrate human cancers

Tumor growth is allowed by its ability to escape immune system surveillance. An important role in determining tumor evasion from immune control might be played by tumor-infiltrating regulatory lymphocytes. This study was aimed at characterizing phenotype and function of CD8+ CD28- T regulatory cells infiltrating human cancer. Lymphocytes infiltrating primitive tumor lesion and/or satellite lymph node from a series of 42 human cancers were phenotypically studied and functionally analyzed by suppressor assays. The unprecedented observation was made that CD8+ CD28- T regulatory lymphocytes are almost constantly present and functional in human tumors, being able to inhibit both T cell proliferation and cytotoxicity. CD4+ CD25+ T regulatory lymphocytes associate with CD8+ CD28- T regulatory cells so that the immunosuppressive activity of tumor-infiltrating regulatory T cell subsets, altogether considered, may become predominant. The infiltration of regulatory T cells seems tumor related, being present in metastatic but not in metastasis-free satellite lymph nodes; it likely depends on both in situ generation (via cytokine production) and recruitment from the periphery (via chemokine secretion). Collectively, these results have pathogenic relevance and implication for immunotherapy of cancer.     

Coexistence of predominantly nonculturable rhizobia with diverse, endophytic bacterial taxa within nodules of wild legumes

A previous analysis showed that Gammaproteobacteria could be the sole recoverable bacteria from surface-sterilized nodules of three wild species of Hedysarum. In this study we extended the analysis to eight Mediterranean native, uninoculated legumes never previously investigated regarding their root-nodule microsymbionts. The structural organization of the nodules was studied by light and electron microscopy, and their bacterial occupants were assessed by combined cultural and molecular approaches. On examination of 100 field-collected nodules, culturable isolates of rhizobia were hardly ever found, whereas over 24 other bacterial taxa were isolated from nodules. None of these nonrhizobial isolates could nodulate the original host when reinoculated in gnotobiotic culture. Despite the inability to culture rhizobial endosymbionts from within the nodules using standard culture media, a direct 16S rRNA gene PCR analysis revealed that most of these nodules contained rhizobia as the predominant population. The presence of nodular endophytes colocalized with rhizobia was verified by immunofluorescence microscopy of nodule sections using an Enterobacter-specific antibody. Hypotheses to explain the nonculturability of rhizobia are presented, and pertinent literature on legume endophytes is discussed.     

Effects of high-fat diet exposure during fetal life on type 2 diabetes development in the progeny

Nutrition during fetal life is a critical factor contributing to diabetes development in adulthood. The aim of our study was to verify: 1) whether a high-fat (HF) diet in young adult mice induces alterations in beta-cell mass, proliferation, neogenesis, and apoptosis, as well as insulin sensitivity and secretion; 2) whether these alterations may be reversible after HF diet suspension; 3) the effects in a first (F1) and second generation (F2) of mice without direct exposure to a HF diet after birth. Type 2 diabetes developed in adult mice on a HF diet, in F1 mice that were HF diet-exposed during fetal or neonatal life, and in F2 mice whose mothers were HF diet-exposed during their fetal life. beta-cell mass, replication, and neogenesis were high in HF diet-exposed mice and decreased after diet suspension. beta-cell mass and replication remained high in F1 mice and decreased in F2 mice whose mothers were exposed to a HF diet. beta-cell neogenesis was present in adult mice on a HF diet and in F1 mice that were HF diet-exposed during fetal and/or neonatal life. We conclude that a HF diet during fetal life, particularly if combined with the same insult during the suckling period, can induce the type 2 diabetes phenotype, which can be directly transmitted to the progeny even in the absence of additional dietary insults.     

Interaction of the Bacillus subtilis RNase P with the 30S ribosomal subunit

Ribonuclease P (RNase P) is a ribozyme required for the 5' maturation of all tRNA. RNase P and the ribosome are the only known ribozymes conserved in all organisms. We set out to determine whether this ribonucleoprotein enzyme interacts with other cellular components, which may imply other functions for this conserved ribozyme. Incubation of the Bacillus subtilis RNase P holoenzyme with fractionated B. subtilis cellular extracts and purified ribosomal subunits results in the formation of a gel-shifted complex with the 30S ribosomal subunit at a binding affinity of approximately 40 nM in 0.1 M NH(4)Cl and 10 mM MgCl(2). The complex does not form with the RNase P RNA alone and is disrupted by a mRNA mimic polyuridine, but is stable in the presence of high concentrations of mature tRNA. Endogenous RNase P can also be detected in the 30S ribosomal fraction. Cleavage of a pre-tRNA substrate by the RNase P holoenzyme remains the same in the presence of the 30S ribosome, but the cleavage of an artificial non-tRNA substrate is inhibited eightfold. Hydroxyl radical protection and chemical modification identify several protected residues located in a highly conserved region in the RNase P RNA. A single mutation within this region significantly reduces binding, providing strong support on the specificity of the RNase P-30S ribosome complex. Our results also suggest that the dimeric form of the RNase P is primarily involved in 30S ribosome binding. We discuss several models on a potential function of the RNase P-30S ribosome complex.     

Tetraiodobenzimidazoles are potent inhibitors of protein kinase CK2

A series of novel iodinated benzimidazoles have been prepared by iodination of respective benzimidazole with iodine and periodic acid in sulfuric acid solution. Additionally several 2-substituted- and N-1-carboxymethyl-substituted derivatives of 4,5,6,7-tetraiodobenzimidazole (TIBI) were obtained. For sake of comparison, some new 4,5,6,7-tetrabromobenzimidazoles were also synthesized. The ability of the new compounds to inhibit protein kinase CK2 has been evaluated. The results show that 4,5,6,7-tetraiodobenzimidazoles are more powerful inhibitors of CK2 than their tetrabrominated analogs. Molecular modeling supports the experimental data showing that tetraiodobenzimidazole moiety fills better the binding pocket than respective tetrabromo and tetrachlorocompounds. To note that 4,5,6,7-tetraiodobenzimidazole (TIBI) is one of the most efficient CK2 inhibitors (K_i = 23 nM) described to date.