5-alpha-reductase type I (SRD5A1) is up-regulated in non-small cell lung cancer but does not impact proliferation, cell cycle distribution or apoptosis

Background  

Non-small cell lung cancer (NSCLC) is one of the most frequent malignancies and has a high mortality rate due to late detection and lack of efficient treatments. Identifying novel drug targets for this indication may open the way for new treatment strategies. Comparison of gene expression profiles of NSCLC and normal adjacent tissue (NAT) allowed to determine that 5-alpha-reductase type I (SRD5A1) was up-regulated in NSCLC compared to NAT. This raised the question whether SRD5A1 was involved in sustained proliferation and survival of NSCLC.     

Trisubstituted and tetrasubstituted pyrazolines as a novel class of cell-growth inhibitors in tumor cells with wild type p53

Derivatives with scaffolds of 1,3,5-tri-substituted pyrazoline and 1,3,4,5-tetra-substituted pyrazoline were synthesized and tested for their inhibitory effects versus the p53^+/+ HCT116 and p53^?/? H1299 human tumor cell lines. Several compounds were active against the two cell lines displaying IC₅₀ values in the low micromolar range with a clearly more pronounced effect on the p53^+/+ HCT116 cells. The compound class shows excellent developability due to the modular synthesis, allowing independent optimization of all three to four key substituents to improve the properties of the molecules.     

Fab is the most efficient format to express functional antibodies by yeast surface display

Multiple formats are available for engineering of monoclonal antibodies (mAbs) by yeast surface display, but they do not all lead to efficient expression of functional molecules. We therefore expressed four anti-tumor necrosis factor and two anti-IpaD mAbs as single-chain variable fragment (scFv), antigen-binding fragment (Fab) or single-chain Fabs and compared their expression levels and antigen-binding efficiency. Although the scFv and scFab formats are widely used in the literature, 2 of 6 antibodies were either not or weakly expressed. In contrast, all 6 antibodies expressed as Fab revealed strong binding and high affinity, comparable to that of the soluble form. We also demonstrated that the variations in expression did not affect Fab functionality and were due to variations in light chain display and not to misfolded dimers. Our results suggest that Fab is the most versatile format for the engineering of mAbs.     

Mutations in Multidomain Protein MEGF8 Identify a Carpenter Syndrome Subtype Associated with Defective Lateralization

Carpenter syndrome is an autosomal-recessive multiple-congenital-malformation disorder characterized by multisuture craniosynostosis and polysyndactyly of the hands and feet; many other clinical features occur, and the most frequent include obesity, umbilical hernia, cryptorchidism, and congenital heart disease. Mutations of RAB23, encoding a small GTPase that regulates vesicular transport, are present in the majority of cases. Here, we describe a disorder caused by mutations in multiple epidermal-growth-factor-like-domains 8 (MEGF8), which exhibits substantial clinical overlap with Carpenter syndrome but is frequently associated with abnormal left-right patterning. We describe five affected individuals with similar dysmorphic facies, and three of them had either complete situs inversus, dextrocardia, or transposition of the great arteries; similar cardiac abnormalities were previously identified in a mouse mutant for the orthologous Megf8. The mutant alleles comprise one nonsense, three missense, and two splice-site mutations; we demonstrate in zebrafish that, in contrast to the wild-type protein, the proteins containing all three missense alterations provide only weak rescue of an early gastrulation phenotype induced by Megf8 knockdown. We conclude that mutations in MEGF8 cause a Carpenter syndrome subtype frequently associated with defective left-right patterning, probably through perturbation of signaling by hedgehog and nodal family members. We did not observe any subject with biallelic loss-of function mutations, suggesting that some residual MEGF8 function might be necessary for survival and might influence the phenotypes observed.     

Differential expression of two somatostatin genes during zebrafish embryonic development

We have identified the cDNAs of two new zebrafish preprosomatostatins, PPSS1 and PPSS3, in addition to the previously cloned PPSS2 (Argenton et al., 1999). PPSS1 is the orthologue of mammalian PPSSs, with a conserved C-terminal SS-14 sequence, PPSS2 is a divergent SS precursor and PPSS3 is a cortistatin-like prohormone. Using whole-mount in situ hybridisation, we have analysed the expression of PPSS1 and PPSS2 in zebrafish embryos up to 5 days post fertilisation. PPSS1 was expressed in the developing pancreas and central nervous system (CNS), whereas PPSS2 expression was exclusively pancreatic. In the CNS, PPSS1 was detected in several areas, in particular in the vagal motor nucleus and in cells that pioneer the tract of the postoptic commissure. PPSS1 was also expressed transiently in the telencephalon and spinal motor neurons. In all areas but the telencephalon PPSS1 was coexpressed with islet-1.     

Alteration of arachidonic acid metabolism with spleen microsomes of irradiated rats

Arachidonic acid is metabolized by a rat spleen microsomes cyclooxygenase into prostaglandin D₂, thromboxane B₂, 12-hydroxy-5, 8, 10-heptadecadienoic acid and by a lipoxygenase into 12-hydroxy-5, 8, 10, 14-eicosatetraenoic acid and other unidentified compounds as analyzed by a radiometric thin-layer chromatography method and by gas-chromatography-mass spectrometry. This conversion is modified when spleen microsomes are obtained from whole body irradiated rats. Furthermore, if exogenous cofactors are added to the incubation medium, other changes appear that are different for the lipoxygenase and the cyclooxygenase activities. The results suggest a regulatory role of cofactors on both enzymes and/or a modification of sensitivity of the microsomal fraction from irradiated rats to effectors.     

Identifying cell and molecular stress after radiation in a three-dimensional (3-D) model of oral mucositis

Mature adipocytes are excellent candidates to influence tumor behavior through heterotypic signaling processes since these cells produce hormones, growth factors, cytokines and other molecules, a heterogeneous group of molecules named adipokines. Using a 2D coculture system, we demonstrate that breast tumor cells previously co-cultivated with mature adipocytes exhibit radioresistance and an earlier and higher increase in the effector kinase Chk1, a phenotype that was associated with decreased cell death as compared to tumor cells grown alone. Interestingly, the adipocytes-induced tumor changes taking place during the coculture time preceding the exposure to IR were sufficient to confer the radioresistant effect. Notorious among the changes brought by adipocytes was the significant increase of IL-6 expression in tumor cells, whose activity may well account for the observed tumor cell protection from IR toxicity. Indeed, our data confirmed the protective role of this cytokine as tumor cells incubated after irradiation with recombinant IL-6 exhibit an increased in Chk1 phosphorylation and a radioresistant phenotype, thus far recapitulating the effects observed in the presence of adipocytes. Our current study sheds light on a new role of tumor-surrounding adipocytes in fostering a radioresistant phenotype in breast tumors, a finding that might have important clinical implications in obese patients that frequently exhibit aggressive diseases.     

Serum hemorphin‐7 levels are decreased in obesity

Objective:

Hemorphin peptides exhibit biological activities that interfere with the endorphin system, the inflammatory response, and blood‐pressure control. VV‐hemorphin‐7 and LVV‐hemorphin‐7 peptides exert a hypotensive effect, in particular, by inhibiting the renin–angiotensin system. Furthermore, levels of circulating hemorphin‐7 peptides have been found to be decreased in diseases such as type 1 and type 2 diabetes.

Design and Methods:

Because type 2 diabetes and obesity share common features, such as insulin resistance, microinflammation, high glomerular‐filtration rate (GFR), and cardiovascular risk, we evaluated serum VV‐hemorphin‐7 like immunoreactivity (VVH7‐i.r.) levels, using an enzyme‐linked immunosorbent assay method, on a group of 54 obese subjects without diabetes or hypertension, compared with a group of 33 healthy normal‐weight subjects.

Results:

Circulating VVH7‐i.r. levels were significantly decreased in the obese group compared with the control group (1.98 ± 0.19 vs. 4.86 ± 0.54 µmol/l, respectively, P < 0.01), and a significant negative correlation between VVH7‐i.r. and diastolic blood pressure (DBP) was found in obese patients (r = ?0.35, P = 0.011). There was no significant correlation between VVH7‐i.r. level and insulin resistance, metabolic syndrome, or GFR.

Conclusions:

The decreased serum hemorphin‐7 found in obese subjects, as in diabetes, may contribute to the development of hypertension and to the cardiovascular risk associated with these metabolic diseases.