Although APC mutations occur at a high frequency in colorectal cancers, few studies have performed a comprehensive analysis by screening the whole gene for mutations and assessing allelic loss. APC seems to act as a tumor-suppressor gene in a ''nonclassical'' fashion: data from familial adenomatous polyposis (FAP) show that the site of the germ-line mutation determines the type of ''second hit'' in FAP tumors, and simple protein inactivation is selected weakly, if at all. In this study, we screened the entire coding region of APC for mutations and assessed allelic loss in a set of 41 colorectal cancer cell lines. Of 41 cancers, 32 (83%) showed evidence of APC mutation and͞or allelic loss. We identified several APC mutations and found a ''hotspot'' for somatic mutation in sporadic colorectal tumors at codon 1,554. Our results suggest that APC mutations occur in the great majority of colorectal cancers, the exceptions almost all being RER؉ tumors, which may substitute for altered APC function by mutations in ␤-catenin and͞or at other loci. When combined with previously published data, our results show that there is interdependence of the ''two hits'' at APC in sporadic colorectal tumors as well as in FAP. APC mutations in the ''mutation cluster region,'' especially those close to codon 1,300, are associated with allelic loss, whereas tumors with mutations outside this region tend to harbor truncating mutations. The causes of this phenomenon are probably selection for retained N-terminal and lost C-terminal APC functions, effects on ␤-catenin levels, and APC protein stability.

It is not clear whether APC mutations are sufficient for early colorectal adenomas to grow or whether additional mutations at other loci are required. We previously have screened 210 early colorectal adenomas from familial adenomatous polyposis patients for mutations and allelic loss at APC. Here, we determined whether allelic loss at APC had any effect on the nearby ␣-catenin gene. However, loss on 5q in familial adenomatous polyposis adenomas rarely extended as far as ␣-catenin, and no differences in ␣-catenin protein expression were found in tumors that showed loss encompassing both APC and ␣-catenin. We then screened all 210 tumors for mutations at candidate loci other than APC (K-ras, ␤-catenin, and allelic loss at 1p33-p35 and 1p36) and for microsatellite instability (MSI). Each of these loci has been implicated previously in early colorectal tumorigenesis. One tumor harbored a ␤-catenin mutation and another MSI, but none showed K-ras mutation or allelic loss at 1p33-p35 or 1p36. These data support the following hypotheses derived from sporadic colorectal tumors: ␤-catenin mutations are generally an alternative to mutations at APC, MSI is not usually an early phenomenon in colorectal tumorigenesis, and K-ras mutations are more typical of large-and moderate-sized adenomas. Contrary to some previous reports, chromosome 1p allelic loss is infrequent in very early adenomas. APC mutations are generally sufficient for colorectal tumors to grow to about 1-cm diameter, although chance mutations at other loci can provide these early colorectal adenomas with a selective advantage, and some colorectal tumors may develop along a pathway not involving APC.

The objective of this study was to investigate the effects of two sources of electromagnetic fields (EMFs) on the proteome of cerebellum, hippocampus, and frontal lobe in Balb/c mice following long-term whole body irradiation. Three equally divided groups of animals (6 animals/group) were used; the first group was exposed to a typical mobile phone, at a SAR level range of 0.17-0.37 W/kg for 3 h daily for 8 months, the second group was exposed to a wireless DECT base (Digital Enhanced Cordless Telecommunications/Telephone) at a SAR level range of 0.012-0.028 W/kg for 8 h/day also for 8 months and the third group comprised the sham-exposed animals. Comparative proteomics analysis revealed that long-term irradiation from both EMF sources altered significantly (p < 0.05) the expression of 143 proteins in total (as low as 0.003 fold downregulation up to 114 fold overexpression). Several neural function related proteins (i.e., Glial Fibrillary Acidic Protein (GFAP), Alpha-synuclein, Glia Maturation Factor beta (GMF), and apolipoprotein E (apoE)), heat shock proteins, and cytoskeletal proteins (i.e., Neurofilaments and tropomodulin) are included in this list as well as proteins of the brain metabolism (i.e., Aspartate aminotransferase, Glutamate dehydrogenase) to nearly all brain regions studied. Western blot analysis on selected proteins confirmed the proteomics data. The observed protein expression changes may be related to brain plasticity alterations, indicative of oxidative stress in the nervous system or involved in apoptosis and might potentially explain human health hazards reported so far, such as headaches, sleep disturbance, fatigue, memory deficits, and brain tumor long-term induction under similar exposure conditions.

Brain laterality has been observed in animals and humans structurally, functionally, and behaviorally. MRI and CT scans have revealed pathological and normal brain asymmetry. A coarse assessment of rat or human brain fails to expose profound left/right differences, while a finer examination of its structure reveals an array of asymmetric features. This lateralization may be derived from evolutionary, genetic, developmental, epigenetic, and pathologic factors. However, brain structure and function is complex and macroscopic or microscopic asymmetries may be hard to discern from random fluctuations. This study concentrated on the hippocampus and we explored lateralization employing a molecular high-throughput approach. Using proteomic analysis based on a combined approach of 2-D PAGE and MS, we examined differential protein expression in the hippocampi (left vs. right) of young adult male rats. Initial proteomic analysis demonstrated quantitative differences of approximately eighty proteins between the right (RH) and left hippocampus (LH). These were primarily energy-, cell metabolism-, stress-inducible chaperone proteins and cytoskeleton- proteins. Analysis revealed higher abundance of metabolic enzymes related to cellular energy metabolism, in the RH than the LH. In contrast, higher concentrations of proteins which are located mainly in astrocytes were shown in the LH than the RH. Immunoblotting of brain-specific proteins, on single animal hippocampal lysates confirmed the expression of Dynamin-1, DRP2, synapsin-1 and others, to be higher in the RH than LH lysates. These findings demonstrate major laterality in the expression of protein molecules between the two hippocampi providing a fertile field for mapping studies relating molecular, neuroimaging and functional data. Undoubtedly, asymmetries found at the animal level are hard to extrapolate to humans; however, studies in animal models will increase our understanding of the developing and adult brain and the healthy and diseased brain.

The infliximab (IFX) has dramatically improved the treatment of Crohn's disease (CD). However, the need for predictive factors, indicative of patients' response to IFX, has yet to be met. In the current study, proteomics technologies were employed in order to monitor for differences in protein expression in a cohort of patients following IFX administration, aiming at identifying a panel of candidate protein biomarkers of CD, symptomatic of response to treatment. We enrolled 18 patients, who either had achieved clinical and serological remission (Rm, n=6), or response (Rs, n=6) and/or were PNRs (n=6), to IFX. Serum samples were subjected to two-dimensional Gel Electrophoresis. Following evaluation of densitometrical data, protein spots exhibiting differential expression among the groups, were further characterized by MALDI-TOF-MS. Identified proteins where evaluated by immunoblot analysis while functional network association was carried out to asses significance. Proteins apolipoprotein A-I (APOA1), apolipoprotein E (APOE), complement C4-B (CO4B), plasminogen (PLMN), serotransferrin (TRFE), beta-2-glycoprotein 1 (APOH), and clusterin (CLUS) were found to be up-regulated in the PNR and Rs groups whereas their levels displayed no changes in the Rm group when compared to baseline samples. Additionally, leucine-rich alpha-2-glycoprotein (A2GL), vitamin D-binding protein (VTDB), alpha-1B-glycoprotein (A1BG) and complement C1r subcomponent (C1R) were significantly increased in the serum of the Rm group. Through the incorporation of proteomics technologies, novel serum marker-molecules demonstrating high sensitivity and specificity are introduced, hence offering an innovative approach regarding the evaluation of CD patients' response to IFX therapy.

Objectives Crohn’s disease (CD) and ulcerative colitis (UC), known collectively as inflammatory bowel disease (IBD), are chronic immuno-inflammatory pathologies of unknown etiology. Despite the frequent utilization of biomarkers in medical practice, there is a relative lack of information regarding validated paediatric biomarkers for IBD. Further, biomarkers proved to be efficacious in adults are frequently extrapolated to the paediatric clinical setting without considering that the pathogenesis of many diseases is distinctly different in children. In the current study, proteomics technology was employed in order to monitor differences in protein expression among adult and children CD patients, in order to identify a panel of candidate protein biomarkers that might be used to improve prognostic-diagnostic accuracy and to advance paediatric medical care. Methods Male and female serum samples from 12 adults and 12 children with active CD were subjected to two-dimensional gel electrophoresis. Following the relative quantitation of protein spots exhibiting a differential expression between the two groups by densitometry, the spots were further characterized by MALDI-TOF-MS. Results were confirmed by Western blot analysis. Results Clusterin (CLUS) was found to be significantly over-expressed in adults with CD, whereas ceruloplasmin (CERU) and apolipoprotein B-100 (APOB) were found to be significantly over-expressed in children indicating that the expression of these proteins might be implicated in the onset or progression of CD in these two sub-groups of patients. Conclusions Interestingly, we found a differential expression of several proteins in adults versus paediatric CD patients. Undoubtedly, future experiments using a larger cohort of CD patients are needed to evaluate the relevance of our preliminary findings.

Background: To date, the elucidation of serum protein alterations in male breast cancer (MBC) has not been extensively studied, due to the rarity of the disease. Materials and Methods: In the present work, two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) were employed to detect differences in serum protein expression between patients with MBC and healthy controls. Results: A panel of differentially expressed serum proteins was identified, including proteins involved in the regulation of the cell cycle [e.g. cell division cycle 7-related protein kinase (CDC7)], in mitochondrial function [e.g. mitochondrial aldehyde dehydrogenase (ALDH2) and dimethyladenosine transferase 1 (TFB1M)], in lipid metabolism and transport [e.g. apolipoprotein A-I (APOA1) and E (APOE)], in apoptosis and immune response [e.g. CD5 antigen-like (CD5L), clusterin (CLUS) and C-C motif chemokine 14 (CCL14)], in transcription (e.g. protein SSX3 and signal transducer and activator of transcription 3 (STAT3)], in invasion and metastasis (e.g. alpha-2-HS-glycoprotein (FETUA)], in estrogen synthesis [aromatase (CYP19A1)] and other diverse biological roles [e.g. actin-related protein 2/3 complex subunit 4 (ARPC4), dual specificity mitogen-activated protein kinase kinase 4 (MP2K4), ectoderm-neural cortex protein 1 (ENC1), and matrix metalloproteinase-27 (MMP27)]. Conclusion: These findings provide valuable insight into the distinct clinicopathological features of MBC and indicate that select serum proteomic markers may help improve MBC management.

No abstract