Publications by authors named "V Quillien"

81 Publications

Microplastics contamination in pearl-farming lagoons of French Polynesia.

J Hazard Mater 2021 Jun 11;419:126396. Epub 2021 Jun 11.

Univ Brest, Ifremer, CNRS, IRD, LEMAR, F-29280 Plouzané, France.

Pearl-farming is the second most important source of income in French Polynesia. However, tropical lagoons are fragile ecosystems with regard to anthropogenic pressures like plastic pollution, which threaten marine life and the pearl oyster-related economy. Here, we investigated the spatial distribution of microplastics (MP) and concentrations in surface water (SW), water column (WC) and cultivated pearl oyster (PO) from three pearl-farming atolls with low population and tourism. Microplastics were categorized by their size class, shape, colour and polymer type identified using FTIR spectroscopy. Widespread MP contamination was observed in every study site (SW, 0.2-8.4 MP m; WC, 14.0-716.2 MP m; PO, 2.1-125.0 MP g dry weight), with high contamination in the WC highlighting the need to study the vertical distribution of MP, especially as this compartment where PO are reared. A large presence of small (< 200 µm) and fragment-shaped (> 70%) MP suggests that they result from the breakdown of larger plastic debris. The most abundant polymer type was polyethylene in SW (34-39%), WC (24-32%), while in PO, polypropylene (14-20%) and polyethylene were more evenly distributed (9-21%). The most common MP identified as black-grey polyethylene and polypropylene matches the polymer and colour of ropes and collectors questioning a pearl-farming origin.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126396DOI Listing
June 2021

Impact of EPclin on adjuvant therapeutic decision making and comparison of EPclin to the PREDICT tool.

Int J Biol Markers 2021 Jun 22;36(2):57-63. Epub 2021 May 22.

Centre Eugène Marquis, Unicancer, Rennes, France.

Purpose: Genomic signatures, such as EndoPredict, may help clinicians to decide which adjuvant treatment is the most appropriate.

Methods: We propose the EndoPredict assay for unclear cases of adjuvant treatment in patients treated in our comprehensive cancer center. We prospectively and retrospectively report the decision of adjuvant treatment before and after the EndoPredict assay, respectively, compared to the PREDICT's tool scores.

Results: From November 2016 to March 2019, 159 breast cancer tumors were analyzed and presented before and after the EndoPredict assay. Before the EndoPredict results, clinicians recommended chemotherapy for 57 patients (57/159, 36%). A total of 108 patients (108/159, 68%) were classified as EPclin high-risk score. There was only a slight agreement between clinicians' decisions and EPclin risk score. The EPclin score led to 37% changes in treatment (59/159); chemotherapy was favored in 80% of cases (47/59). The PREDICT tool recommended chemotherapy for 16 high-risk patients (16/159, 10%).

Conclusion: Although genomic tests were developed in order to de-escalate adjuvant treatment, in our comprehensive cancer center the use of the EndoPredict assay led to an increase in prescribed chemotherapy.
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http://dx.doi.org/10.1177/17246008211012424DOI Listing
June 2021

Tracing key genes associated with the Pinctada margaritifera albino phenotype from juvenile to cultured pearl harvest stages using multiple whole transcriptome sequencing.

BMC Genomics 2020 Sep 25;21(1):662. Epub 2020 Sep 25.

Ifremer, UMR EIO 241, Centre du Pacifique, BP 49, 98719, Taravao, Tahiti, Polynéise française, France.

Background: Albino mutations are commonly observed in the animal kingdom, including in bivalves. In the black-lipped pearl oyster Pinctada margaritifera, albino specimens are characterized by total or partial absence of colouration resulting in typical white shell phenotype expression. The relationship of shell colour with resulting cultured pearl colour is of great economic interest in P. margaritifera, on which a pearl industry is based. Hence, the albino phenotype provides a useful way to examine the molecular mechanisms underlying pigmentation.

Results: Whole transcriptome RNA-sequencing analysis comparing albino and black wild-type phenotypes at three stages over the culture cycle of P. margaritifera revealed a total of 1606, 798 and 187 differentially expressed genes in whole juvenile, adult mantle and pearl sac tissue, respectively. These genes were found to be involved in five main molecular pathways, tightly linked to known pigmentation pathways: melanogenesis, calcium signalling pathway, Notch signalling pathway, pigment transport and biomineralization. Additionally, significant phenotype-associated SNPs were selected (N = 159), including two located in the Pif biomineralization gene, which codes for nacre formation. Interestingly, significantly different transcript splicing was detected between juvenile (N = 1366) and adult mantle tissue (N = 313) in, e.g., the tyrosinase Tyr-1 gene, which showed more complex regulation in mantle, and the Notch1 encoding gene, which was upregulated in albino juveniles.

Conclusion: This multiple RNA-seq approach provided new knowledge about genes associated with the P. margaritifera albino phenotype, highlighting: 1) new molecular pathways, such as the Notch signalling pathway in pigmentation, 2) associated SNP markers with biomineraliszation gene of interest like Pif for marker-assisted selection and prevention of inbreeding, and 3) alternative gene splicing for melanin biosynthesis implicating tyrosinase.
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http://dx.doi.org/10.1186/s12864-020-07015-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7517651PMC
September 2020

Microplastics induce dose-specific transcriptomic disruptions in energy metabolism and immunity of the pearl oyster Pinctada margaritifera.

Environ Pollut 2020 Nov 8;266(Pt 3):115180. Epub 2020 Jul 8.

Ifremer, Institut Louis-Malardé, IRD, Univ Polynésie Française, EIO, F-98719, Taravao, Tahiti, Polynésie française, France. Electronic address:

A combined approach integrating bioenergetics and major biological activities is essential to properly understand the impact of microplastics (MP) on marine organisms. Following experimental exposure of polystyrene microbeads (micro-PS of 6 and 10 μm) at 0.25, 2.5, and 25 μg L, which demonstrated a dose-dependent decrease of energy balance in the pearl oyster Pinctada margaritifera, a transcriptomic study was conducted on mantle tissue. Transcriptomic data helped us to decipher the molecular mechanisms involved in P. margaritifera responses to micro-PS and search more broadly for effects on energetically expensive maintenance functions. Genes related to the detoxification process were impacted by long-term micro-PS exposure through a decrease in antioxidant response functioning, most likely leading to oxidative stress and damage, especially at higher micro-PS doses. The immune response was also found to be dose-specific, with a stress-related activity stimulated by the lowest dose present after a 2-month exposure period. This stress response was not observed following exposure to higher doses, reflecting an energy-limited capacity of pearl oysters to cope with prolonged stress and a dramatic shift to adjust to pessimum conditions, mostly limited and hampered by a lowered energetic budget. This preliminary experiment lays the foundation for exploring pathways and gene expression in P. margaritifera, and marine mollusks in general, under MP exposure. We also propose a conceptual framework to properly assess realistic MP effects on organisms and population resilience in future investigations.
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http://dx.doi.org/10.1016/j.envpol.2020.115180DOI Listing
November 2020

Inhibitor of Apoptosis Proteins Determines Glioblastoma Stem-Like Cell Fate in an Oxygen-Dependent Manner.

Stem Cells 2019 06 28;37(6):731-742. Epub 2019 Mar 28.

Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille, France.

In glioblastomas, apoptosis inhibitor proteins (IAPs) are involved in apoptotic and nonapoptotic processes. We previously showed that IAP inhibition induced a loss of stemness and glioblastoma stem cells differentiation by activating nuclear factor-κB under normoxic conditions. Hypoxia has been shown to modulate drug efficacy. Here, we investigated how IAPs participate in glioblastoma stem-like cell maintenance and fate under hypoxia. We showed that in a hypoxic environment, IAPs inhibition by GDC-0152, a small-molecule IAPs inhibitor, triggered stem-like cell apoptosis and decreased proliferation in four human glioblastoma cell lines. We set up a three-dimensional glioblastoma spheroid model in which time-of-flight secondary ion mass spectrometry analyses revealed a decrease in oxygen levels between the periphery and core. We observed low proliferative and apoptotic cells located close to the hypoxic core of the spheres and glial fibrillary acidic protein cells at their periphery. These oxygen-dependent GDC-0152 antitumoral effects have been confirmed on human glioblastoma explants. Notably, serine-threonine kinase activation analysis revealed that under hypoxic conditions, IAP inhibition activated ataxia telangiectasia and Rad3-related protein signaling. Our findings provide new insights into the dual mechanism of action of IAP inhibitors that depends on oxygen level and are relevant to their therapeutic application in tumors. Stem Cells 2019;37:731-742.
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http://dx.doi.org/10.1002/stem.2997DOI Listing
June 2019
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