Nicolas Vallet

Dr. Nicolas Vallet

U976 INSERM, Team 4, Paris, France
+1
orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
21 January 2021 in Scientific Reports
Verified
Journal Article
Open access
PDF file
AFAmelie Foucault
Amelie Foucault
NVNicolas Vallet
Nicolas Vallet
NRNoemie Ravalet
Noemie Ravalet
FPFrederic Picou
Frederic Picou
MBMarie C. Bene
Marie C. Bene
OHOlivier Herault
Olivier Herault
The impact of pesticides on health is a major public health concern. A higher risk to develop chronic lymphoid malignancies has been demonstrated to be associated with occupational pesticide exposure (OPE). By contrast, little is known of the impact of OPE on the occurrence of myeloid malignancies especially acute myeloid leukemia (AML). The purpose of this meta-analysis is to summarize data on the association between OPE and AML. A relevant dataset of case–control studies was extracted. Among 6784 references extracted, 14 were selected, representing 3,955 AML patients and 9,948 control subjects diagnosed between 1976 and 2010. An adverse association was found between OPE and AML (OR = 1.51; 95%CI: 1.10–2.08), not affected by sensitivity analyses. Funnel plot asymmetry suggested a publication bias underestimating OR. Stratified analysis showed the association to be driven by studies with: (1) monocentric AML patients and hospital-based control population, (2) Newcastle–Ottawa scale > 6 and the group of studies identified as with the lowest risk, (3) exposure assessment through peer-to-peer interview, (4) diagnosis in North America and Asia and after 1995, (5) restriction to de novo AML. Moreover, the association between OPE and AML was significant with insecticides. These findings broaden the spectrum of pesticide toxicity to myeloid malignancies.

1 October 2018 in Pharmacological Research
Verified
Journal Article
Closed access
FPFREDERIC PICOU
FREDERIC PICOU
CDChristelle Debeissat
Christelle Debeissat
JBJérôme Bourgeais
Jérôme Bourgeais
NGNathalie Gallay
Nathalie Gallay
EFElise Ferrié
Elise Ferrié
EGEmmanuel Gyan
Emmanuel Gyan

8 December 2022 in Blood
Verified
Journal Article
Closed access
PDF file
NVNicolas Vallet
Nicolas Vallet
SGSophie Le Grand
Sophie Le Grand
LBLouise Bondeelle
Louise Bondeelle
BHBénédicte Hoareau
Bénédicte Hoareau
ACAurélien CORNEAU
Aurélien CORNEAU
DMDavid Michonneau
David Michonneau
Administration of azithromycin after allogeneic hematopoietic stem cell transplantation for hematologic malignancies has been associated with relapse in a randomized phase 3 controlled clinical trial. Studying 240 samples from patients randomized in this trial is a unique opportunity to better understand the mechanisms underlying relapse, the first cause of mortality after transplantation. We used multi-omics on patients’ samples to decipher immune alterations associated with azithromycin intake and post-transplantation relapsed malignancies. Azithromycin was associated with a network of altered energy metabolism pathways and immune subsets, including T cells biased toward immunomodulatory and exhausted profiles. In vitro, azithromycin exposure inhibited T-cell cytotoxicity against tumor cells and impaired T-cell metabolism through glycolysis inhibition, down-regulation of mitochondrial genes, and up-regulation of immunomodulatory genes, notably SOCS1. These results highlight that azithromycin directly affects immune cells that favor relapse, which raises caution about long-term use of azithromycin treatment in patients at high risk of malignancies. The ALLOZITHRO trial was registered at www.clinicaltrials.gov as #NCT01959100.

21 December 2017 in Haematologica
Verified
Journal Article
Open access
PDF file
NVNicolas Vallet
Nicolas Vallet
FFFlore Sicre de Fontbrune
Flore Sicre de Fontbrune
MLMichaël Loschi
Michaël Loschi
DDDeborah Desmier
Deborah Desmier
AVAlban Villate
Alban Villate
RLRégis Peffault de Latour
Régis Peffault de Latour
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired hematopoietic stem cell disorder which manifests with hemolysis (classical PNH) due to loss of expression of the CD55 and CD59 proteins, which leads to complement mediated cell lysis.[1][1] Despite being the only curative treatment for PNH

4 October 2022 in Scientific Data
Verified
Journal Article
Open access
PDF file
NVNicolas Vallet
Nicolas Vallet
DMDavid Michonneau
David Michonneau
STSimon Tournier
Simon Tournier
Reproducibility crisis urge scientists to promote transparency which allows peers to draw same conclusions after performing identical steps from hypothesis to results. Growing resources are developed to open the access to methods, data and source codes. Still, the computational environment, an interface between data and source code running analyses, is not addressed. Environments are usually described with software and library names associated with version labels or provided as an opaque container image. This is not enough to describe the complexity of the dependencies on which they rely to operate on. We describe this issue and illustrate how open tools like Guix can be used by any scientist to share their environment and allow peers to reproduce it. Some steps of research might not be fully reproducible, but at least, transparency for computation is technically addressable. These tools should be considered by scientists willing to promote transparency and open science.

17 January 2021 in The Oncologist
Verified
Journal Article
Open access
PDF file
NVNicolas Vallet
Nicolas Vallet
NBNicolas Boissel
Nicolas Boissel
EEElisabeth Elefant
Elisabeth Elefant
FCFlorian Chevillon
Florian Chevillon
HPHélène Pasquer
Hélène Pasquer
CPCatherine Poirot
Catherine Poirot
Background: Preventing premature ovarian failure (POF) is a major challenge in oncology. With conventional regimens, cytotoxicity-associated POF involves primordial follicles (PF) pool depletion by apoptosis or overactivation mechanisms, notably mediated by the ABL/TAp63 and PI3K/Akt/mTOR pathways. New anticancer treatments have been designed to target pathways implicated in tumor growth. Although concerns regarding fertility arise with these targeted therapies, we hypothesized that targeted therapies may exert off-tumor effects on PF that might delay POF. We provide an overview of evidence concerning these off-tumor effects on PF. Limitations and future potential implications of these findings are discussed. Design: PubMed was searched by combining Boolean operators with the following keywords: fertility, ovarian, follicle, anti-tumoral, cancer, targeted, cytotoxic, and chemotherapy. Results: Cisplatin-related PF apoptosis via the ABL/TAp63 pathway was targeted with a tyrosine kinase inhibitor, imatinib, in mice, but effects were recently challenged by findings on human ovarian xenografts in mice. In cyclophosphamide-treated mice, PI3K/Akt/mTOR pathway inhibition with mTOR inhibitors and AS101 preserved the PF pool. Proteasome and GSK3 inhibitors were evaluated for direct and indirect follicle DNA damage prevention. Surprisingly, evidence for cytotoxic drug association with PF pool preservation was found. We also describe selected non-anticancer molecules that may minimize gonadotoxicity. Conclusion: Not all anticancer treatments are associated with POF, particularly since the advent of targeted therapies. The feasibility of associating a protective drug targeting PF exhaustion mechanisms with cytotoxic treatments should be evaluated, as a way of decreasing the need for conventional fertility preservation techniques. Further evaluations are required for transfer into clinical practice. Implications for Practice: Anticancer therapies are associated with infertility in 10%–70% of patients, which is the result of primordial follicles pool depletion. Alone or associated with gonadotoxic treatments, some targeted therapies may exert favorable off-targets effects on the primordial follicle pool by slowing down their exhaustion. Current evidence of these effects relies on murine models or human in vitro models. Evaluation of these protective strategies in humans is challenging; however, if these results are confirmed with clinical and biological data, it not only could be a new approach to female fertility preservation but also would change standard fertility strategies.