Studies on the side-chain hydroxylation of ifosfamide and its bromo analogue

Deutero-substituted (alpha,alpha,alpha',alpha'-tetradeuterated) derivatives of ifosfamide (IF-d(4)) and its bromo analogue were synthesised. In vitro metabolic studies showed that microsomal hydroxylation of IF-d(4) is slower than for unlabelled compound, suggesting that kinetic isotope effect operates during those transformations. At the same time deutero-substituted derivatives are more active against L1210 leukaemia in mice than unlabelled compounds, suggesting a negative role of side-chain hydroxylation metabolic pathways in the anticancer activity of ifosfamide and its analogues.     

Fast identification of folded human protein domains expressed in <Emphasis Type="Italic">E. coli</Emphasis> suitable for structural analysis

Background  

High-throughput protein structure analysis of individual protein domains requires analysis of large numbers of expression clones to identify suitable constructs for structure determination. For this purpose, methods need to be implemented for fast and reliable screening of the expressed proteins as early as possible in the overall process from cloning to structure determination.     

Genomic deletion and promoter methylation status of Hypermethylated in Cancer 1 (HIC1) in mantle cell lymphoma

Mantle cell lymphomas (MCL), characterized by the t(11;14)(q13;q32), frequently carry secondary genetic alterations such as deletions in chromosome 17p involving the TP53 locus. Given that the association between TP53-deletions and concurrent mutations of the remaining allele is weak and based on our recent report that the Hypermethylated in Cancer 1 (HIC1) gene, that is located telomeric to the TP53 gene, may be targeted by deletions in 17p in diffuse large B-cell lymphoma (DLBCL), we investigated whether HIC1 inactivations might also occur in MCL. Monoallelic deletions of the TP53 locus were detected in 18 out of 59 MCL (31%), while overexpression of p53 protein occurred in only 8 out of 18 of these MCL (44%). In TP53-deleted MCL, the HIC1 gene locus was co-deleted in 11 out of 18 cases (61%). However, neither TP53 nor HIC1 deletions did affect survival of MCL patients. In most analyzed cases, no hypermethylation of the HIC1 exon 1A promoter was observed (17 out of 20, 85%). However, in MCL cell lines without HIC1-hypermethylation, the mRNA expression levels of HIC1 were nevertheless significantly reduced, when compared to reactive lymph node specimens, pointing to the occurrence of mechanisms other than epigenetic or genetic events for the inactivation of HIC1 in this entity.     

The genetic basis of graves' disease

The presented comprehensive review of current knowledge about genetic factors predisposing to Graves' disease (GD) put emphasis on functional significance of observed associations. In particular, we discuss recent efforts aimed at refining diseases associations found within the HLA complex and implicating HLA class I as well as HLA-DPB1 loci. We summarize data regarding non-HLA genes such as PTPN22, CTLA4, CD40, TSHR and TG which have been extensively studied in respect to their role in GD. We review recent findings implicating variants of FCRL3 (gene for FC receptor-like-3 protein), SCGB3A2 (gene for secretory uteroglobin-related protein 1- UGRP1) as well as other unverified possible candidate genes for GD selected through their documented association with type 1 diabetes mellitus: Tenr-IL2-IL21, CAPSL (encoding calcyphosine-like protein), IFIH1(gene for interferon-induced helicase C domain 1), AFF3, CD226 and PTPN2. We also review reports on association of skewed X chromosome inactivation and fetal microchimerism with GD. Finally we discuss issues of genotype-phenotype correlations in GD.     

Faunal composition of geometrid moths changes with altitude in an Andean montane rain forest

Aim The objective of this study was to describe and interpret the changes in faunal composition in the moth family Geometridae (Lepidoptera) along a small‐scale elevational gradient in a tropical montane rain forest. This gradient was compared with a large‐scale latitudinal gradient in Europe. Location Investigations were carried out in the province Zamora‐Chinchipe in southern Ecuador along a gradient ranging from 1040 to 2677 m above sea level at twenty‐two sites. Methods Moths were sampled with light‐traps in three field periods in 1999 and 2000 and subsequently sorted and determined to species or morphospecies. Results We analysed 13,938 specimens representing 1010 species of geometrid moths. The proportional contribution of subtaxa to the local geometrid fauna changes along the elevational gradient at all systematic levels considered. While proportions of species of the subfamilies Ennominae, Sterrhinae and Geometrinae significantly decrease, the proportion of Larentiinae increases with increasing altitude. Changes also occur within the subfamilies Ennominae and Larentiinae. The host–plant specialist ennomine tribes Cassymini, Macariini and Palyadini completely vanish, and the proportion of the tribe Boarmiini decreases at high altitudes. In contrast, the remaining tribes (mostly comprising polyphagous species) either do not show proportional changes (Azelinini, Nacophorini, Nephodiini, Ourapterygini) or even increase (Caberini, ‘Cratoptera group’). Within Larentiinae, the species proportion of the genus Eois decreases, whereas concomitantly the proportion of Eupithecia increases. There is a remarkable similarity between the altitudinal patterns in Ecuador and those found along the latitudinal gradient in Europe. Main conclusions Species of the subfamily Larentiinae seem to be particularly well‐adapted to harsh environmental conditions, towards both high altitudes and latitudes. They might disproportionately profit from lower predation at higher altitudes. Many changes in the faunal composition can be explained by expected host–plant requirements of the species involved. Our results show that diversity estimates based on taxon ratios which are assumed to be constant must be regarded with caution because such ratios can change rapidly along environmental gradients.     

Examination of Apoptosis Signaling in Pancreatic Cancer by Computational Signal Transduction Analysis

Background

Pancreatic ductal adenocarcinoma (PDAC) remains an important cause of cancer death. Changes in apoptosis signaling in pancreatic cancer result in chemotherapy resistance and aggressive growth and metastasizing. The aim of this study was to characterize the apoptosis pathway in pancreatic cancer computationally by evaluation of experimental data from high-throughput technologies and public data bases. Therefore, gene expression analysis of microdissected pancreatic tumor tissue was implemented in a model of the apoptosis pathway obtained by computational protein interaction prediction.

Methodology/Principal Findings

Apoptosis pathway related genes were assembled from electronic databases. To assess expression of these genes we constructed a virtual subarray from a whole genome analysis from microdissected native tumor tissue. To obtain a model of the apoptosis pathway, interactions of members of the apoptosis pathway were analysed using public databases and computational prediction of protein interactions. Gene expression data were implemented in the apoptosis pathway model. 19 genes were found differentially expressed and 12 genes had an already known pathophysiological role in PDAC, such as Survivin/BIRC5, BNIP3 and TNF-R1. Furthermore we validated differential expression of IL1R2 and Livin/BIRC7 by RT-PCR and immunohistochemistry. Implementation of the gene expression data in the apoptosis pathway map suggested two higher level defects of the pathway at the level of cell death receptors and within the intrinsic signaling cascade consistent with references on apoptosis in PDAC. Protein interaction prediction further showed possible new interactions between the single pathway members, which demonstrate the complexity of the apoptosis pathway.

Conclusions/Significance

Our data shows that by computational evaluation of public accessible data an acceptable virtual image of the apoptosis pathway might be given. By this approach we could identify two higher level defects of the apoptosis pathway in PDAC. We could further for the first time identify IL1R2 as possible candidate gene in PDAC.     

Complete elimination of hostplant quinolizidine alkaloids by larvae of a polyphagous lycaenid butterfly,Callophrys rubi

Caterpillars of the lycaenid butterfly Callophrys rubi accept a variety of hostplants. When fed inflorescences or leaves of Genista tinctoria (a natural hostplant) or Lupinus polyphyllus (a non-host), the larvae completely eliminate quinolizidine alkaloids ingested from their food in their frass. No alkaloids are stored. Infestation by the parasitoid wasp Distatrix sancus (Braconidae) did not affect alkaloid elimination. The presence of an effective anti-toxin system is discussed with reference to the evolution of hostplant relationships in the genus Callophrys. There is no evidence that in the secondarily myrmecoxenous larvae of C. rubi hostplantderived chemical defense takes the place of former myrmecophily.     

Turning Up the Heat on a Hotspot: DNA Barcodes Reveal 80% More Species of Geometrid Moths along an Andean Elevational Gradient

We sampled 14,603 geometrid moths along a forested elevational gradient from 1020–3021 m in the southern Ecuadorian Andes, and then employed DNA barcoding to refine decisions on species boundaries initially made by morphology. We compared the results with those from an earlier study on the same but slightly shorter gradient that relied solely on morphological criteria to discriminate species. The present analysis revealed 1857 putative species, an 80% increase in species richness from the earlier study that detected only 1010 species. Measures of species richness and diversity that are less dependent on sample size were more than twice as high as in the earlier study, even when analysis was restricted to an identical elevational range. The estimated total number of geometrid species (new dataset) in the sampled area is 2350. Species richness at single sites was 32–43% higher, and the beta diversity component rose by 43–51%. These impacts of DNA barcoding on measures of richness reflect its capacity to reveal cryptic species that were overlooked in the first study. The overall results confirmed unique diversity patterns reported in the first investigation. Species diversity was uniformly high along the gradient, declining only slightly above 2800 m. Species turnover also showed little variation along the gradient, reinforcing the lack of evidence for discrete faunal zones. By confirming these major biodiversity patterns, the present study establishes that incomplete species delineation does not necessarily conceal trends of biodiversity along ecological gradients, but it impedes determination of the true magnitude of diversity and species turnover.