Identification of O-Linked Glycoproteins Binding to the Lectin Helix pomatia Agglutinin as Markers of Metastatic Colorectal Cancer

Background Protein glycosylation is an important post-translational modification shown to be altered in all tumour types studied to date. Mucin glycoproteins have been established as important carriers of O-linked glycans but other glycoproteins exhibiting altered glycosylation repertoires have yet to be identified but offer potential as biomarkers for metastatic cancer. Methodology In this study a glycoproteomic approach was used to identify glycoproteins exhibiting alterations in glycosylation in colorectal cancer and to evaluate the changes in O-linked glycosylation in the context of the p53 and KRAS (codon 12/13) mutation status. Affinity purification with the carbohydrate binding protein from Helix pomatia agglutinin (HPA) was coupled to 2-dimensional gel electrophoresis with mass spectrometry to enable the identification of low abundance O-linked glycoproteins from human colorectal cancer specimens. Results Aberrant O-linked glycosylation was observed to be an early event that occurred irrespective of the p53 and KRAS status and correlating with metastatic colorectal cancer. Affinity purification using the lectin HPA followed by proteomic analysis revealed annexin 4, annexin 5 and CLCA1 to be increased in the metastatic colorectal cancer specimens. The results were validated using a further independent set of specimens and this showed a significant association between the staining score for annexin 4 and HPA and the time to metastasis; independently (annexin A4: Chi square 11.45, P = 0.0007; HPA: Chi square 9.065, P = 0.0026) and in combination (annexin 4 and HPA combined: Chi square 13.47; P = 0.0002). Conclusion Glycoproteins showing changes in O-linked glycosylation in metastatic colorectal cancer have been identified. The glycosylation changes were independent of p53 and KRAS status. These proteins offer potential for further exploration as biomarkers and potential targets for metastatic colorectal cancer

APC mutation associated with late onset of familial adenomatous polyposis.

International audienceFamilial adenomatous polyposis is an autosomal dominantly inherited disorder. Mutation studies in the corresponding gene (APC) may provide information for predictive tests for persons at risk in affected families. We report here a new mutation in exon 6 (codon 233) of the APC gene and clinical data in a large family with late onset of the disease in most affected persons. Image

High Affinity Interaction between a Bivalve C-type Lectin and a Biantennary Complex-type N -Glycan Revealed by Crystallography and Microcalorimetry

International audienc

The invasive crayfish Cherax quadricarinatus facing chlordecone in Martinique: Bioaccumulation and depuration study

The redclaw crayfish, Cherax quadricarinatus, was introduced to Martinique Island for aquaculture purposes at the beginning of the 21st century, in an attempt to revitalize the freshwater crustacean aquaculture sector. Mainly due to its high economical value, it was intentionally released in the wild and was caught and sold by fishermen. Martinican rivers are polluted by chlordecone, considered as one of the worst Persistant Organic Pollutants (POP). Despite its dangerousness, it was used until 1993 in the French West Indies against a banana pest and was always found in the ecosystems. This study aimed to investigate the level of contamination in the muscle of crayfish caught in the wild, as well as the potential of bioconcentration and depuration in the C. quadricarinatus muscle. This study could allow us to quantify the risk for consumers but also, to evaluate a depuration process to reduce the risk related to its consumption. Using both in-vitro and in-situ experiments, results highlighted the importance of the chlordecone concentration in the water and the time of exposure to the pollutant. The bioconcentration seems to be very quick and continuous in crayfish muscle, as chlordecone can be detectable as early as 6 h of exposure, whatever the concentration tested. Finally, it appears that, even after 20 days of depuration in chlordecone-free water, chlordecone concentrations remained higher to the residual maximum limit (i.e. 20 ng/g wet weight), concluding that the decontamination of the muscle seems not very efficient, and the risk for the Martinican people could be serious

Application de la methode des cartes oligonucleotidiques T1 a la differenciation de souches virales de la fievre aphteuse

SIGLECNRS T 56314 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Quality assessment of ice-stored tropical yellowfin tuna (Thunnus albacares) and influence of vacuum and modified atmosphere packaging

Metagenomic, microbial, chemical and sensory analyses of Thunnus albacares from Martinique and stored in ice (AIR – 0 °C), vacuum (VP – 4/8 °C) and modified atmosphere packaging (MAP – 4/8 °C) (70% CO2 – 30% O2) were carried out. The organoleptic rejection of AIR tuna was observed at day 13 when total bacterial counts equaled 106–107 CFU g−1. No extension of shelf-life was provided by VP and MAP. According to 16S rRNA gene sequence analyzed by Illumina MiSeq and PCR-TTGE, Rhodanobacter terrae was the main species of the freshly caught tuna. At the sensory rejection time, Brochothrix thermosphacta and Pseudomonas dominated the AIR products while B. thermosphacta alone or a mix of B. thermosphacta, Enterobacteriaceae and lactic acid bacteria (LAB) dominated the microbiota of MAP and VP products, respectively. The pH value remained stable in all trials, ranging from 5.77 to 5.97. Total volatile basic nitrogen (TVBN) and trimethylamine (TMA-N) concentrations were weak and not significantly different between batches. Lipid oxidation increased in the samples containing O2 (MAP > AIR). The initial concentration of histamine was high (75–78 mg kg−1) and stable up to 8 days but then significantly decreased in all trials to reach 25–30 mg kg−1, probably due to the presence of histamine-decomposing bacteria

Effect of vacuum and modified atmosphere packaging on the microbiological, chemical and sensory properties of tropical red drum ( Sciaenops ocellatus ) fillets stored at 4 °C

Aims The effect of vacuum (VP – 4 °C) and CO2/N2–atmosphere (MAP – 4 °C) packaging on the quality of red drum fillets compared with whole gutted iced fish was investigated. Methods and results A metagenomic approach, bacterial enumeration and isolation, biochemical and sensory analyses were carried out. The organoleptic rejection of whole fish was observed at day 15 whereas VP and MAP fillets appeared unacceptable only after 29 days. At these dates, total mesophilic counts reached 107–108 CFU g− 1. According to Illumina MiSeq sequencing, Arthrobacter, Chryseobacterium, Brevibacterium, Staphylococcus and Kocuria were the main genera of the fresh red drum fillets. At the sensory rejection time, lactic acid bacteria (LAB), particularly Carnobacterium sp., dominated the microbiota of both types of packaging. The pH value of fresh samples was between 5.96 and 6.37 and did not vary greatly in all trials. Total volatile basic nitrogen (TVBN) and trimethylamine (TMA) concentrations were low and not represent reliable indicators of the spoilage, contrary to some biogenic amines (cadaverine, putrescine and tyramine). Conclusion Chilled packed fillets of red drum have an extended shelf-life compared to whole gutted iced fish. Overall, few differences in sensory and microbial quality were observed between the VP and MAP samples. Significance and impact of the study Next-Generation Sequencing (NGS) provided data on the microbiota of a tropical fish

An integrative analytical study of the functional and antioxidant properties of selected varieties of pink guava Psidium guajava L.

International audience(Guava (Psidium guajava L.) is a tropical fruit widely consumed around the world. The study wascarried out on four selected guava varieties grown in Martinique. Two fruit harvests were gathered at two-yearintervals, at the green/yellow color change maturity stage. First, we established the homogeneity of all fruitbatches by bootstrapping, ANOVA, box plot and multiple comparison statistical analysis on physicalparameters. Red Supreme Ruby clearly differs from the other three varieties, whereas the results for CentenoProlific are between Beauséjour and Enana Cuba. We determined on puree obtained from a homogeneousbatch of each variety the physicochemical and functional properties as well as the antioxidant properties. Ourresults show that the combination of lycopene and vitamin C, and their synergistic mechanisms in the fruitextracts may be responsible for the high antioxidant activity of guava puree, and we demonstrate a statisticallysignificant positive correlation between EC50 and lycopene

Trophic niche of the invasive Cherax quadricarinatus and extent of competition with native shrimps in insular freshwater food webs

International audienceQuantifying the trophic niche of non-native species is a valuable way to measure both their invasion success and putative impacts on recipient food webs. Theory predicts that successful invasive species display flexible diet depending on environment conditions, have large trophic niche, and can overlap the trophic niche of functionally similar native species. We investigated these predictions using the redclaw crayfish (Cherax quadricarinatus) as an invasive species model and omnivorous and detritivorous shrimps as native competitors in recently invaded insular Martinican streams (Caribbean region). Although the redclaw crayfish is globally widespread, little is known about its trophic ecology and potential impacts on other crustaceans in its non-native regions. Using stable isotope analyses to quantify the trophic ecology of redclaw crayfish, we found that it occupied a central position in the food webs, with a primary consumer tendency at the population level. Evidence for ontogenetic shifts was found with different trajectories across streams, highlighting its trophic flexibility to environmental conditions. However, redclaw fed on a limited range of resources (small niche sizes) probably due to the local context, characterised by simplified food webs. Crayfish and shrimps shared partly similar food resources (20.5 ± 9.7% of niche overlap with omnivorous shrimps and 14.9 ± 13.8% with detritivorous shrimps). Finally, a slight shift in trophic niche (without niche constriction) of native crustaceans (mainly omnivorous shrimps) was observed when cooccurring with crayfish. Stable isotope analysis revealed here no evidence of striking impact of the newly introduced crayfish on the trophic ecology of native shrimps, but we call for further investigations to assess potential longer-term repercussions on native communities