Stromal-derived IGF2 promotes colon cancer progression via paracrine and autocrine mechanisms.

The insulin-like growth factor (IGF)2/IGF1 receptor (IGF1R) signaling axis has an important role in intestinal carcinogenesis and overexpression of IGF2 is an accepted risk factor for colorectal cancer (CRC) development. Genetic amplifications and loss of imprinting contribute to the upregulation of IGF2, but insufficiently explain the extent of IGF2 expression in a subset of patients. Here, we show that IGF2 was specifically induced in the tumor stroma of CRC and identified cancer-associated fibroblasts (CAFs) as the major source. Further, we provide functional evidence that stromal IGF2, via the paracrine IGF1R/insulin receptor axis, activated pro-survival AKT signaling in CRC cell lines. In addition to its effects on malignant cells, autocrine IGF2/IGF1R signaling in CAFs induced myofibroblast differentiation in terms of alpha-smooth muscle actin expression and contractility in floating collagen gels. This was further augmented in concert with transforming growth factor-ß (TGFß) signaling suggesting a cooperative mechanism. However, we demonstrated that IGF2 neither induced TGFß/smooth muscle actin/mothers against decapentaplegic (SMAD) signaling nor synergized with TGFß to hyperactivate this pathway in two dimensional and three dimensional cultures. IGF2-mediated physical matrix remodeling by CAFs, but not changes in extracellular matrix-modifying proteases or other secreted factors acting in a paracrine manner on/in cancer cells, facilitated subsequent tumor cell invasion in organotypic co-cultures. Consistently, colon cancer cells co-inoculated with CAFs expressing endogenous IGF2 in mouse xenograft models exhibited elevated invasiveness and dissemination capacity, as well as increased local tumor regrowth after primary tumor resection compared with conditions with IGF2-deficient CAFs. In line, expression of IGF2 correlated with elevated relapse rates and poor survival in CRC patients. In agreement with our results, high-level coexpression of IGF2 and TGFß was predicting adverse outcome with higher accuracy than increased expression of the individual genes alone. Taken together, we demonstrate that stroma-induced IGF2 promotes colon cancer progression in a paracrine and autocrine manner and propose IGF2 as potential target for tumor stroma cotargeting strategies.

Autocrine WNT2 signaling in fibroblasts promotes colorectal cancer progression.

The canonical WNT signaling pathway is crucial for intestinal stem cell renewal and aberrant WNT signaling is an early event in colorectal cancer (CRC) development. Here, we show for the first time that WNT2 is one of the most significantly induced genes in CRC stroma as compared to normal stroma. The impact of stromal WNT2 on carcinoma formation or progression was not addressed so far. Canonical WNT/ß-catenin signaling was assessed using a 7TGP-reporter construct. Furthermore, effects of WNT2 on fibroblast migration and invasion were determined using siRNA-mediated gene silencing. Tumor cell invasion was studied using organotypic raft cultures and in vivo significance was assessed via a xenograft mouse model. We identified cancer-associated fibroblasts (CAFs) as the main source of WNT2. CAF-derived WNT2 activated canonical signaling in adenomatous polyposis coli/ß-catenin wild-type colon cancer cells in a paracrine fashion, whereas no hyperactivation was detectable in cell lines harboring mutations in the adenomatous polyposis coli/ß-catenin pathway. Furthermore, WNT2 activated autocrine canonical WNT signaling in primary fibroblasts, which was associated with a pro-migratory and pro-invasive phenotype. We identified FZD8 as the putative WNT2 receptor in CAFs. Three-dimensional organotypic co-culture assays revealed that WNT2-mediated fibroblast motility and extracellular matrix remodeling enhanced cancer cell invasion of cell lines even harboring mutations in the adenomatous polyposis coli/ß-catenin pathway. Thus, suggesting a tumor-promoting influence on a broad range of CRC. In line, WNT2 also promotes tumor growth, invasion and metastasis in vivo. Moreover, high WNT2 expression is associated with poor prognosis in human CRC. The identification of the pro-malignant function of stromal derived WNT2 in CRC classifies WNT2 and its receptor as promising stromal targets to confine cancer progression in combination with conventional or targeted therapies.

Variations in truncal body circumferences affect fat mass quantification with bioimpedance analysis.

OBJECTIVE: To test the hypothesis that variations in trunk circumferences influence the accuracy of bioimpedance analysis (BIA) for assessment of percent fat mass (%FM). SUBJECTS AND METHODS: %FM was predicted with BIA, and compared with air-displacement plethysmography (ADP) in a small sample of 35 overweight (OW), 21 normal weight and 8 underweight volunteers. Waist and hip circumferences were assessed, and 15 of the OW subjects were measured before and after weight reduction. RESULTS: BIA and ADP provided similar cross-sectional estimates of group mean %FM (28.9±10.0 and 31.3±13.0%, respectively). However, within individuals, there were large between-method differences (Diff(BIA-ADP)) ranging from -13 to +13 %FM. Furthermore, we found a systematic bias of BIA related to the degree of adiposity. Consequently, %FM and fat mass loss during weight reduction in OW were underestimated with BIA when compared with ADP. Waist and hip circumferences were inversely associated with resistance (R) and reactance (P<0.01), and with Diff(BIA-ADP) (P<0.001). In women, the variability in hip circumference explained 76%, and in men, the variability in waist circumference explained 59% of Diff(BIA-ADP). CONCLUSION: Resistance changes associated with variations in trunk circumferences decrease resistance, and therefore impair the accuracy of BIA to assess %FM.

Psychopharmacotherapy in eating disorders: a systematic analysis.

The most common and serious eating disorders, which are particularly prevalent in young women, are anorexia nervosa (AN), bulimia nervosa (BN), and binge-eating disorders (BED). Further, the prevalence of unspecific hyperphagous eating disorders frequently causing obesity is substantially increasing. All of these eating disorders tend to be chronic and comorbid to psychiatric diagnoses. Because of the multifactorial etiology, these disorders require a multimodal treatment. Among different treatment options, symptomatic psychopharmacotherapy has been an important component, and especially in recent decades, it has been subject to many trials. This article gives an overview of the current literature, summarizing diagnostic criteria, epidemiology, and critically discussing psychopharmacotherapy of those eating disorders. Based on the literature and our clinical experience, the psychopharmacological recommendations for patients with AN, BN, and BED are suggested.

[Stigmatization. Consideration from a theological-dermatologic perspective]. / Stigmatisierung. Eine Betrachtung von theologisch-dermatologischer Seite.

Stigmatization is associated with considerable psychosocial impairment. Patients with chronic skin disease are especially prone to stigmatization and reduced quality of life. In contrast, patients with self-produced cutaneous artifacts receive an emotional response from family members and doctors. Stigmatization of a religious nature is always difficult for non-participants to understand. We focus on the suffering of the patient, using the example of a historical person, Saint Rita of Cascia, who bore a stigma on her forehead. We discuss why suffering is presented in this manner, and how salvation can be the positive effect of suffering.

Hormone profiles, body mass index and aging male symptoms: results of the Androx Vienna Municipality study.

Aging in the male is accompanied by steroid hormonal decline, and men may develop symptoms associated with hypogonadism. Increased awareness of 'andropause' in recent years has led to greater demand for hormonal assessments, resulting in a rising burden for health economics. We conducted a cross-sectional study to define men at risk for hypogonadism, in whom further hormonal investigation should be performed. We examined 664 blue-collar workers aged 40-60 years at their workplace and determined hormonal status and body mass index (BMI). Men with an abnormal urogenital status and those on medication that might affect endocrine status were excluded from the study. All participants completed the validated Aging Male Symptom (AMS) questionnaire and obtained scores for psychological symptoms, somatovegetative symptoms, and sexual symptoms. Multiple logistic regression analyses revealed a significantly increased risk (represented by the odds ratio) of psychological symptoms for men with low levels of testosterone and/or bioavailable testosterone (BAT). Increased BMI as well as low testosterone levels and/or low BAT levels raised the risk of somatovegetative symptoms. Each decrease of BAT by 1 ng/ml caused an approximately 1.8-fold increase of the risk (odds ratio = 1.832, p = 0.005). Additional independent risk factors were increased age and low luteinizing hormone (LH) level. Men aged 55 years with BMI > 28 kg/m2 and with somatovegetative symptoms and moderate or severe psychological symptoms had a 7.2-fold increase in the risk of a BAT level < 1.5 ng/ml compared to men without these risk factors (p < 0.001). Sensitivity and specificity were 75% and 71%, respectively. The AMS score combined with age and BMI provides an easy and convenient method to identify men with probable androgen deficiency who require hormonal assessment.

Developmental regulation of an instability element from the Drosophila fushi tarazu mRNA.

The Drosophila fushi tarazu (ftz) mRNA is one of the shortest-lived metazoan mRNAs, and its instability is crucial for proper development of the embryo. Previously, we identified two cis-acting elements that are required for ftz mRNA degradation, one within the 5' one-third and another in the 3'UTR of the message. Here we focus on the 3'UTR element termed FIE3 (ftz instability element in the 3'UTR). To investigate the developmental regulation of the FIE3-dependent degrading activity we measured the abundance of an FIE3-containing mRNA in ovaries, unfertilized eggs, and different larval and adult tissues. We found that FIE3-degrading activity is present at all developmental stages and tissues examined, except in the ovary. Activation of the FIE3-dependent mRNA decay is independent of fertilization because it could be triggered by egg activation. Finally, we provide evidence that mutation of conserved elements within FIE3 had no effect on mRNA instability.

Expression and distribution of CYP2C enzymes in rat basal ganglia.

The function and integrity of the basal ganglia is modulated by sex steroids whose activity may be controlled by P450 enzymes, such as members of the CYP2C subfamily. The expression of CYP2C enzymes in rat basal ganglia was examined by immunohistochemistry along with some of the factors that might control their expression. Whereas no CYP2C11 or CYP2C12 immunoreactivity was detected in the basal ganglia of either male or female rats, marked CYP2C13 immunoreactivity was evident in neurones of the subthalamic nucleus, substantia nigra, and interpeduncular nucleus. Strong CYP2C13 immunoreactivity was also expressed in the cortex, olfactory tubercle, hippocampus, dentate gyrus, hypothalamic nuclei, medial habenular nucleus, red nucleus, and medial forebrain bundle. Similar results were found in male and female rats. Following 6-hydroxydopamine lesioning of the nigro-striatal tract, tyrosine hydroxylase immunoreactivity was absent and CYP2C13 immunoreactivity was decreased markedly in the substantia nigra pars compacta, implying its presence in dopaminergic neurones. Modulation of sex steroids, using castrated rats, had no effect on the number of CYP2C13 positive neurones in the substantia nigra pars compacta. These results indicate that CYP2C13 protein is constitutively and widely expressed in rat brain. However, its expression is not sex-specific and is unaffected by castration. The role of CYP2C13 in brain is unknown but it may be involved in the generation of neurosteroids and catecholoestrogens.

Expression and localisation of CYP2D enzymes in rat basal ganglia.

P450 enzymes in the CYP2D subfamily have been suggested to contribute to the susceptibility of individuals in developing Parkinson's disease. We have used specific anti-peptide antisera and peroxidase immunohistochemistry to investigate the expression of CYP2D enzymes in the rat brain and some possible factors that may affect their regulation. In male Wistar rats, CYP2D1 was not detected in the basal ganglia or in any other brain region. CYP2D2 was weakly expressed within neurones of the subthalamic nucleus, substantia nigra and interpeduncular nucleus as well as in the hippocampus, dentate gyrus, red nucleus and pontine nucleus. CYP2D3 and CYP2D4 were absent from the basal ganglia, although moderate amounts of CYP2D3 were detected within fibres of the oculomotor root, and very low levels of CYP2D4 were present in white matter tracts. In contrast, CYP2D5 was extensively expressed in the basal ganglia, including neurones in the subthalamic nucleus, substantia nigra and interpeduncular nucleus, as well as other areas of the brain, including the ventral tegmental area, piriform cortex, hippocampus, dentate gyrus, medial habenular nucleus, thalamic nucleus and pontine nucleus. Lesioning of the nigro-striatal tract to cause almost a complete loss of tyrosine hydroxylase containing neurones in the substantia nigra, also reduced the number of neurones expressing CYP2D5 by 50%, indicating that CYP2D5 is expressed in dopaminergic neurones. Castration of pre-pubertal or adult Wistar rats had no effect on the number of CYP2D5-positive neurones in the substantia nigra. Although Dark Agouti rats lack hepatic CYP2D2, expression in the midbrain was similar to that of Wistar rats; furthermore, there was no difference in expression or distribution between male and female rats. In contrast to naive rats, extensive expression of CYP2D4 was found throughout the basal ganglia and in other brain nuclei in Wistar rats treated with not only clozapine, but also saline, suggesting that CYP2D4 may be induced as a result of mild stress. The function of CYP2D enzymes in the brain remains unknown, but their selective localisation suggests a physiological role in neuronal activity and in adaptation to abnormal situations.

P450 enzymes and Parkinson's disease: the story so far.

Environmental or endogenous toxins may cause nigral cell death in Parkinson's disease (PD) as a result of genetic susceptibility conferred by altered expression of P450 enzymes. Attention over the last 10 years has focused on CYP2D6 polymorphisms and susceptibility to PD. This review summarizes reports arising from both phenotypic and genotypic studies involving CYP2D6 and PD. Phenotypic studies have failed to support a link between CYP2D6 and PD. The more powerful genetic studies initially indicated a link between CYP2D6B mutations and PD, but critical analysis of the literature and recent studies emerging from independent laboratories fail to confirm this. Mutations in CYP2D6B are also not implicated in familial PD. As yet, there is no conclusive evidence to suggest that CYP2D6 polymorphisms confer susceptibility to PD. Whether polymorphisms in other P450s (for example, CYP1A1 and CYP2E1) are implicated in PD remains to be established.

Co-localization of P450 enzymes in the rat substantia nigra with tyrosine hydroxylase.

Susceptibility to develop Parkinson's disease has been linked to abnormalities of P450 enzyme function. Multiple P450 enzymes are expressed in brain but the relationship of these to Parkinson's disease is unknown. We have investigated the expression of P450 enzymes in the rat substantia nigra and their co-localization in tyrosine hydroxylase-positive neurons and astrocytes. Immunohistochemistry was performed using anti-peptide antisera against the following P450 enzymes: CYP1A1, CYP1A2, CYP2B1/2, CYP2C12, CYP2C13/2C6, CYP2D1, CYP2D4, CYP2E1, CYP3A1, CYP3A2 and NADPH-P450 oxidoreductase. Immunoreactivity in nigral cells was found only for CYP2E1 and CYP2C13/2C6. CYP2E1 immunoreactivity was localized to many midbrain nuclei including the substantia nigra pars compacta but not the substantia nigra pars reticulata while immunoreactivity to CYP2C13/2C6 was found in the substantia nigra pars compacta, substantia nigra pars reticulata and many other midbrain nuclei. Sections of rat midbrain double labelled for either CYP2E1 or CYP2C13/2C6 and tyrosine hydroxylase or glial fibrillary acidic protein were examined for co-localization by confocal laser scanning microscopy. CYP2E1 and CYP2C13/2C6 immunoreactivity was found in tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta but not in glial cells. CYP2C13/2C6, but not CYP2E1, was also found in non-glial, non-tyrosine hydroxylase-expressing cells in the substantia nigra pars reticulata. Isoniazid induction increased CYP2E1 fluorescence signal intensity from nigral dopaminergic neurons. At least two P450 enzymes are found in nigral dopamine containing cells and one, namely CYP2E1, is selectively localized to this cell population. CYP2E1 is a potent generator of free radicals which may contribute to nigral pathology in Parkinson's disease. The expression of CYP2E1 in dopaminergic neurons in substantia nigra raises the possibility of a causal association with Parkinson's disease.

Involvement of programmed cell death in morphogenesis of the vertebrate inner ear.

An outstanding challenge in developmental biology is to reveal the mechanisms underlying the morphogenesis of complex organs. A striking example is the developing inner ear of the vertebrate, which acquires a precise three-dimensional arrangement of its constituent epithelial cells to form three semicircular canals, a central vestibule and a coiled cochlea (in mammals). In generating a semicircular canal, epithelial cells seem to 'disappear' from the center of each canal. This phenomenon has been variously explained as (i) transdifferentiation of epithelium into mesenchyme, (ii) absorption of cells into the expanding canal or (iii) programmed cell death. In this study, an in situ DNA-end labeling technique (the TUNEL protocol) was used to map regions of cell death during inner ear morphogenesis in the chicken embryo from embryonic days 3.5-10. Regions of cell death previously identified in vertebrate ears have been confirmed, including the ventromedial otic vesicle, the base of the endolymphatic duct and the fusion plates of the semicircular canals. New regions of cell death are also described in and around the sensory organs. Reducing normal death using retrovirus-mediated overexpression of human bcl-2 causes abnormalities in ear morphogenesis: hollowing of the center of each canal is either delayed or fails entirely. These data provide new evidence to explain the role of cell death in morphogenesis of the semicircular canals.

The molecular biology of hair cell regeneration in the avian cochlea.

The sensory cells of the ear, the hair cells, are damaged by loud noise or certain types of drugs. In the bird cochlea, new hair cells are produced to replace those that are lost. Regeneration also occurs in the vestibular epithelia of birds, fish, and mammals but does not occur in the mammalian cochlea. In order to further our understanding of the regeneration process in the bird cochlea, we have begun to identify the genes that are involved. However, the small size of this organ has made it difficult to use traditional molecular biology methods to address these problems. Recently, many molecular techniques have been adapted for use with small amounts of tissue. Northern blot analysis, the ribonuclease protection assay, semiquantitative PCR and differential display of mRNA are all techniques that are being used to greatly improve our understanding of hair cell regeneration and may eventually provide the information necessary to induce regeneration in hearing-impaired humans.

Selective localisation of P450 enzymes and NADPH-P450 oxidoreductase in rat basal ganglia using anti-peptide antisera.

Environmental or endogenous toxins may cause nigral cell death in Parkinson's disease (PD) due to altered expression of P450 enzymes. In rat brain, immunohistochemistry using anti-peptide antisera showed NADPH-P450 oxidoreductase and CYP2B1/2 in various hypothalamic nuclei and CYP1A1 in the globus pallidus, but neither enzyme was expressed in substantia nigra. No specific immunoreactivity to CYP2D1 or CYP3A1 was found in any brain region examined. In contrast, CYP2E1 was expressed in substantia nigra and in striatal blood vessels. Since CYP2E1 is associated with free radical production, it may contribute to the oxidative stress believed to underlie nigral degeneration.

Determinants of Drosophila fushi tarazu mRNA instability.

The fushi tarazu gene is essential for the establishment of the Drosophila embryonic body plan. When first expressed in early embryogenesis, fushi tarazu mRNA is uniformly distributed over most of the embryo. Subsequently, fushi tarazu mRNA expression rapidly evolves into a pattern of seven stripes that encircle the embryo. The instability of fushi tarazu mRNA is probably crucial for attaining this localized pattern of expression. mRNA stability in transgenic embryos was measured by a new method that does not use drugs or external interference. Experiments using hybrid genes that fuse fushi tarazu sequences to those of the stable ribosomal protein A1 mRNA provide evidence for at least two destabilizing elements in the fushi tarazu mRNA, one located within the 5' one-third of the mRNA and the other near the 3' end (termed FIE3 for ftz instability element 3'). The FIE3 lies within a 201-nucleotide sequence just upstream of the polyadenylation signal and can act autonomously to destabilize a heterologous mRNA. Further deletion constructs identified an essential 68-nucleotide element within the FIE3. Lack of homology between this element and other previously identified destabilization sequences suggests that FIE3 contains a novel RNA destabilization element.

Differing features of proteins in membranes may result in antioxidant or prooxidant action: opposite effects on lipid peroxidation of alcohol dehydrogenase and albumin in liposomal systems.

The influence of 3 thiol-containing compounds, bovine serum albumin (fatty acid free: BSA), glutathione (GSH) and yeast alcohol dehydrogenase (YADH) on lipid peroxidation in multilamellar liposomes, prepared from ox-brain phospholipid, was investigated. Thiol-compounds were added either before liposome formation, or after liposome formation; and their effects compared to a positive control. Bovine serum albumin (BSA), an acidic hydrophilic protein, displays a small, concentration dependent, antioxidant effect when added to preformed liposomes. A much larger antioxidant effect was observed when the BSA was entrapped inside the liposome, by adding BSA just prior to liposome preparation. In contrast, a Zn(2+) containing redox enzyme, YADH, a basic hydrophobic membrane-associating protein, displays a large pro-oxidant effect at much lower concentrations especially when entrapped inside the liposome. This was observed also with GSH; but per mole of -SH, YADH was about 18 times as powerful a pro-oxidant perhaps because of structural changes to the membrane. Oxidized glutathione and N-acetylcysteine were also pro-oxidant (cysteine and cystine showed little effect). Formation of thiyl radicals may occur in the presence of iron ions with these pro-oxidant sulphur-containing compounds. Partial protection against lipid peroxidation was observed with EDTA, desferrioxamine and protoporphyrin (IX), potent iron-chelating agents.