Geert Trooskens

Casein-free, gluten-free diets have been reported to mitigate some of the inflammatory gastrointestinal and behavioral traits associated with autism, but the mechanism for this palliative effect has not been elucidated. We recently showed that the opioid peptide beta-casomorphin-7, derived from bovine (bBCM7) milk, decreases cysteine uptake, lowers levels of the antioxidant glutathione (GSH) and decreases the methyl donor S-adenosylmethionine (SAM) in both Caco-2 human GI epithelial cells and SH-SY5Y human neuroblastoma cells. While human breast milk can also release a similar peptide (hBCM-7), the bBCM7 and hBCM-7 vary greatly in potency; as the bBCM-7 is highly potent and similar to morphine in it's effects. Since SAM is required for DNA methylation, we wanted to further investigate the epigenetic effects of these food-derived opioid peptides. In the current study the main objective was to characterize functional pathways and key genes responding to DNA methylation effects of food-derived opioid peptides. SH-SY5Y neuroblastoma cells were treated with 1 μM hBCM7 and bBCM7 and RNA and DNA were isolated after 4 h with or without treatment. Transcriptional changes were assessed using a microarray approach and CpG methylation status was analyzed at 450,000 CpG sites. Functional implications from both endpoints were evaluated via Ingenuity Pathway Analysis 4.0 and KEGG pathway analysis was performed to identify biological interactions between transcripts that were significantly altered at DNA methylation or transcriptional levels (p < 0.05, FDR <0.1). Here we show that hBCM7 and bBCM7, as well as morphine, cause epigenetic changes affecting gene pathways related to gastrointestinal disease and inflammation. These epigenetic consequences exhibited the same potency order as opiate inhibition of cysteine uptake insofar as hBCM7 was less potent than bBCM7, which was less potent than morphine. Our findings indicate that epigenetic effects of milk-derived opiate peptides may contribute to GI dysfunction and inflammation in sensitive individuals. While the current study was performed using SH-SY5Y neuronal cellular models, similar actions on other cells types might combine to cause symptoms of intolerance. These actions may provide a potential contributing mechanism for the beneficial effects of a casein-free diet in alleviating gastrointestinal symptoms in neurological conditions including autism and other conditions. Lastly, our study also contributes to the evolving awareness of a “gut-brain connection”.

492 Background: The effect of VEGF targeted agents on DNA mutations and epigenetic expression in metastatic clear cell renal cancer (mccRCC) has not been reported. We hypothesise that significant DNA mutations and methylation changes occur with treatment which may be associated with resistance. Methods: DNA was extracted from sequential frozen pairs of primary tumour tissue from 14 mccRCC patients, in the SuMR clinical trial (NCT01024205), at presentation (biopsy) and after 3-cycles of sunitinib (nephrectomy). Multiple biopsies were taken to assess for heterogeneity. Biopsy and nephrectomy samples were compared in untreated tumours as controls. Array CGH, Ion Torrent sequencing (48 key ccRCC genes were assessed [Table]), and methylCap-seq DNA methylation analysis were performed. Results: aCGH hierarchical clustering showed that samples from 2/14 patients clustered together (13%). There were no significant increase in copy number variations (CNVs) following treatment with sunitinib. For somatic mutations of the 48 key genes, there were no patients in whom all samples clustered together. Conversely, at methylation level, all samples for each patient clustered. Mean frequency of mutations in the key genes relative to normal kidney was identical for biopsy and nephrectomy samples (n=14 mutations). 12/48 genes had CNVs or mutations in ≥2 patients following treatment with sunitinib (table). VHL was the only gene with significant difference in methylation pre- and post-sunitinib therapy (FDR=0.077; logFC=-0.8734, hypermethylated following sunitinib therapy); there was no difference in VHL methylation pre- and post-renal artery clamping. Conclusions: Intratumoral heterogeneity was not apparent in DNA methylation, unlike DNA. This may facilitate in biomarker research. The significant increase in VHL methylation following sunitinib gives insight into possible mechanisms of resistance at an epigenetic level. [Table: see text]

Staphylococcal enterotoxins may influence the pro-inflammatory pattern of chronic sinus diseases via epigenetic events. This work intended to investigate the potential of staphylococcal enterotoxin B (SEB) to induce changes in the DNA methylation pattern. Nasal polyp tissue explants were cultured in the presence and absence of SEB; genomic DNA was then isolated and used for whole genome methylation analysis. Results showed that SEB stimulation altered the methylation pattern of gene regions when compared with non stimulated tissue. Data enrichment analysis highlighted two genes: the IKBKB and STAT-5B, both playing a crucial role in T- cell maturation/activation and immune response.

It was long assumed that proteins are at least 100 amino acids (AAs) long. Moreover, the detection of short translation products (e.g. coded from small Open Reading Frames, sORFs) is very difficult as the short length makes it hard to distinguish true coding ORFs from ORFs occurring by chance. Nevertheless, over the past few years many such non-canonical genes (with ORFs < 100 AAs) have been discovered in different organisms like Arabidopsis thaliana, Saccharomyces cerevisiae, and Drosophila melanogaster. Thanks to advances in sequencing, bioinformatics and computing power, it is now possible to scan the genome in unprecedented scrutiny, for example in a search of this type of small ORFs.