CXCL12 and TP53 genetic polymorphisms as markers of susceptibility in a Brazilian children population with acute lymphoblastic leukemia (ALL)

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Genetic polymorphisms in the 3′UTR region of the CXCL12 (rs1801157) and TP53 codon 72 (rs1042522) genes may contribute to susceptibility to childhood ALL because they affect some important processes, such as metastasis regulation and tumor suppression. Thus the objective of the present study was to detect the frequency of two genetic polymorphisms in ALL patients and controls and to add information their impact on genetic susceptibility and prognosis. The CXCL12 and TP53 polymorphisms were tested in 54 ALL child patients and in 58 controls by restriction fragment length polymerase chain reaction and allelic specific chain reaction techniques, respectively. The frequencies of both allelic variants were higher in ALL patients than in the controls and indicated a positive association: OR = 2.44; 95 % CI 1.05–5.64 for CXCL12 and OR = 2.20; 95 % CI 1.03–4.70 for TP53. Furthermore, when the two genetic variants were analyzed together, they increased significantly more than fivefold the risk of this neoplasia development (OR = 5.24; 95 % CI 1.39–19.75), indicating their potential as susceptibility markers for ALL disease and the relevance of the allelic variant combination to increased risk of developing malignant tumors. Future studies may indicate a larger panel of genes involved in susceptibility of childhood ALL and other hematological neoplasias.     

Commonality and biosynthesis of the O-methyl phosphoramidate capsule modification in Campylobacter jejuni

In this study we investigated the commonality and biosynthesis of the O-methyl phosphoramidate (MeOPN) group found on the capsular polysaccharide (CPS) of Campylobacter jejuni. High resolution magic angle spinning NMR spectroscopy was used as a rapid, high throughput means to examine multiple isolates, analyze the cecal contents of colonized chickens, and screen a library of CPS mutants for the presence of MeOPN. Sixty eight percent of C. jejuni strains were found to express the MeOPN with a high prevalence among isolates from enteritis, Guillain Barré, and Miller-Fisher syndrome patients. In contrast, MeOPN was not observed for any of the Campylobacter coli strains examined. The MeOPN was detected on C. jejuni retrieved from cecal contents of colonized chickens demonstrating that the modification is expressed by bacteria inhabiting the avian gastrointestinal tract. In C. jejuni 11168H, the cj1415-cj1418 cluster was shown to be involved in the biosynthesis of MeOPN. Genetic complementation studies and NMR/mass spectrometric analyses of CPS from this strain also revealed that cj1421 and cj1422 encode MeOPN transferases. Cj1421 adds the MeOPN to C-3 of the beta-d-GalfNAc residue, whereas Cj1422 transfers the MeOPN to C-4 of D-glycero-alpha-L-gluco-heptopyranose. CPS produced by the 11168H strain was found to be extensively modified with variable MeOPN, methyl, ethanolamine, and N-glycerol groups. These findings establish the importance of the MeOPN as a diagnostic marker and therapeutic target for C. jejuni and set the groundwork for future studies aimed at the detailed elucidation of the MeOPN biosynthetic pathway.     

Determination of ethyl-p-hydroxybenzoate in sow pancreatic juice by reversed-phase high-performance liquid chromatography

We have developed a high-performance liquid chromatographic–UV–Vis–diode-array detection (HPLC–DAD) method for the determination of ethyl-p-hydroxybenzoate, a hydrolytic degradation product of the synthetic protease inhibitor, gabexate-mesilate ethyl-p-(6-guanidinohexanoyloxy) benzoate methanesulfonate (GM) (FOY) in sow pancreatic juice. Methyl-p-hydroxybenzoate (I) was used as the internal standard. The pancreatic juice was deproteinised by acetonitrile and the analytes were chromatographed on a reversed-phase C₁₈ LC column using the gradient elution method. The mobile phase consisted of a solution of 0.017 M orthophosphoric acid and another solution of acetonitrile–water (80:20, v/v). The wavelength of detection was 237 nm. The limit of quantification of the method was 0.20 μM at a 9:1 signal-to-noise ratio. The overall intra- and inter-day accuracy (relative error, RE) ranged from 14.2 to 8.3% and from 13.3 to 9.8, respectively. The overall intra- and inter-day precision (relative standard deviation, RSD) ranged from 7.6 to 2.62% and from 6.7 to 3.1%, respectively. The method proved to be sensitive, specific, accurate and precise and was successfully used to determine the ethyl-p-hydroxybenzoate (II) in sow pancreatic juice.     

Combining conservation priorities and vulnerability of invasion in nature reserves using geospatial tools can optimize management efforts

Hydrobiologia - The management of invasive species in large, little-known, nature reserves is difficult. Weighing the risk of invasion against the conservation value of each sector in nature...     

So alike yet so different. Differential expression of the long non-coding RNAs NORAD and HCG11 in breast cancer subtypes

Breast cancer (BC) is a heterogeneous disease, and it is the leading cause of death among women. NORAD and HCG11 are highly similar lncRNAs that present binding sites for PUMILIO proteins. PUMILIO acts on hundreds of mRNA targets, contributing to the modulation of gene expression. We analyzed the expression levels of NORAD and HCG11 in the BC subtypes luminal A (LA) and basal-like (BL), and the regulatory networks associated with these lncRNAs. In the analysis of TCGA cohort (n=329) and Brazilian BC samples (n=44), NORAD was up-regulated in LA while HCG11 was up-regulated in BL subtype. An increased expression of NORAD is associated with reduced disease-free survival in basal-like patients (p = 0.002), which suggests that its prognostic value could be different in specific subtypes. The biological pathways observed for the HCG11 network are linked to the epithelial-to-mesenchymal transition; while NORAD associated pathways appear to be related to luminal epithelial cell transformation. NORAD and HCG11 regulons respectively present 36% and 21.5% of PUMILIO targets, which suggests that these lncRNAs act as a decoy for PUMILIO. These lncRNAs seem to work as players in the differentiation process that drives breast cells to acquire distinct phenotypes related to a specific BC subtype.     

Micellar environments induce structuring of the N-terminal tail of the prion protein

In the physiological form, the prion protein is a glycoprotein tethered to the cell surface via a C-terminal glycosylphosphatidylinositol anchor, consisting of a largely alpha-helical globular C-terminal domain and an unstructured N-terminal portion. This unstructured part of the protein contains four successive octapeptide repeats, which were shown to bind up to four Cu(2+) ions in a cooperative manner. To mimic the location of the protein on the cell membrane and to analyze possible structuring effects of the lipid/water interface, the conformational preferences of a single octapeptide repeat and its tetrameric form, as well of the fragment 92-113, proposed as an additional copper binding site, were comparatively analyzed in aqueous and dodecylphosphocholine micellar solution as a membrane mimetic. While for the downstream fragment 92-113 no conformational effects were detectable in the presence of DPC micelles by CD and NMR, both the single octapeptide repeat and, in an even more pronounced manner, its tetrameric form are restricted into well-defined conformations. Because of the repetitive character of the rigid structural subdomain in the tetrarepeat molecule, the spatial arrangement of these identical motifs could not be resolved by NMR analysis. However, the polyvalent nature of the repetitive subunits leads to a remarkably enhanced interaction with the micelles, which is not detectably affected by copper complexation. These results strongly suggest interactions of the cellular form of PrP (PrP(c)) N-terminal tail with the cell membrane surface at least in the octapeptide repeat region with preorganization of these sequence portions for copper complexation. There are sufficient experimental facts known that support a physiological role of copper complexation by the octapeptide repeat region of PrP(c) such as a copper-buffering role of the PrP(c) protein on the extracellular surface.     

Bioactive N-terminal undecapeptides derived from parathyroid hormone: the role of alpha-helicity.

The N-terminal 1-34 segment of parathyroid hormone (PTH) is fully active in vitro and in vivo and it can reproduce all biological responses in bone characteristic of the native intact PTH. Recent studies have demonstrated that N-terminal fragments presenting the principal activating domain such as PTH(1-11) and PTH(1-14) with helicity-enhancing substitutions yield potent analogues with PTH(1-34)-like activity. To further investigate the role of alpha-helicity on biological potency, we designed and synthesized by solid-phase methodology the following hPTH(1-11) analogues substituted at positions 1 and/or 3 by the sterically hindered and helix-promoting C(alpha)-tetrasubstituted alpha-amino acids alpha-amino isobutyric acid (Aib), 1-aminocyclopentane-1-carboxylic acid (Ac(5)c) and 1-aminocyclohexane-1-carboxylic acid (Ac(6)c): Ac(5)c-V-Aib-E-I-Q-L-M-H-Q-R-NH(2) (I); Aib-V-Ac(5)c-E-I-Q-L-M-H-Q-R-NH(2) (II); Ac(6)c-V-Aib-E-I-Q-L-M-H-Q-R-NH(2) (III); Aib-V-Ac(6)c-E-I-Q-L-M-H-Q-R-NH(2) (IV); Aib-V-Aib-E-I-Q-L-M-H-Q-R-NH(2) (V); S-V-Aib-E-I-Q-L-M-H-Q-R-NH(2) (VI), S-V-Ac(5)c-E-I-Q-L-M-H-Q-R-NH(2) (VII); Ac(5)c-V-S-E-I-Q-L-M-H-Q-R-NH(2) (VIII); Ac(6)c-V-S-E-I-Q-L-M-H-Q-R-NH(2) (IX); Ac(5)c-V-Ac(5)c-E-I-Q-L-M-H-Q-R-NH(2) (X); Ac(6)c-V-Ac(6)c-E-I-Q-L-M-H-Q-R-NH(2) (XI). All analogues were biologically evaluated and conformationally characterized in 2,2,2-trifluoroethanol (TFE) solution by circular dichroism (CD). Analogues I-V, which cover the full range of biological activity observed in the present study, were further conformationally characterized in detail by nuclear magnetic resonance (NMR) and computer simulations studies. The results of ligand-stimulated cAMP accumulation experiments indicated that analogues I and II are active, analogues III, VI and VII are very weakly active and analogues IV, V, VIII-XI are inactive. The most potent analogue, I exhibits biological activity 3500-fold higher than that of the native PTH(1-11) and only 15-fold weaker than that of the native sequence hPTH(1-34). Remarkably, the two most potent analogues, I and II, and the very weakly active analogues, VI and VII, exhibit similar helix contents. These results indicate that the presence of a stable N-terminal helical sequence is an important but not sufficient condition for biological activity.     

Pichia angusta is an effective biocontrol yeast against postharvest decay of apple fruit caused by Botrytis cinerea and Monilia fructicola

The efficacy of eight isolates of Pichia angusta against three common postharvest pathogens of apple fruit was evaluated for the first time. All tested strains showed significant biocontrol activity against both Botrytis cinerea and Monilia fructicola , whereas efficacy against Penicillium expansum was poor. A leucine-auxotrophic mutant had no significant biocontrol activity against brown rot of apple, while the addition of 0.6–1.2 g L⁻¹ leucine in the fruit wound fully restored the biocontrol activity of this mutant against M. fructicola . Given the extremely well-developed classical and molecular genetics, the availability of genomic libraries, and its complete genomic sequence, this species can serve to elucidate the mechanisms related to biocontrol capacity.