Biological Signatures Resulting From Occupational Exposure to Complex Mixtures of PAHs (PAH-ProMetGen)

April 27, 2023 updated by: University Hospital, Grenoble

Biological Signatures (Proteomics, Metabolomics and Genotoxicity) Associated With Occupational Exposure to PAH Mixtures and Relation With Exposure Biomarkers: Support for the Derivation of Biological Limit Values

This research project aims at better understanding the early biological effects resulting from occupational exposure to complex Polycyclic Aromatic Hydrocarbon (PAH) mixtures.

Current biomarkers used as part of biomonitoring campaigns are biomarkers of exposure, not numerous and poorly related to health effects.

The aim of this study is thus to improve our understanding of biological consequences of such exposures, both in terms of proteins deregulation, metabolism deregulation and genotoxicity.

Study Overview

Detailed Description

PAHs are ubiquitous pollutants inducing several diseases, among which cancer is the most significant endpoint, with increased incidences of lung, skin, and bladder cancers. PAHs induce genotoxic effects (sister chromatids exchange, micronuclei, DNA damage) but require metabolic activation in humans as indirect-acting carcinogens. Thus, the knowledge of metabolic pathways involved following PAH exposure is critical for understanding and preventing cancer risks. Besides, exposure to PAHs is assumed to induce other adverse health effects (diabetes, inflammation, infertility, cardiovascular disease). Unfortunately, early disease-related biomarkers are still largely unknown and our comprehension about the mechanisms involved is still limited. The rare existing biological limit values either refer to not carcinogenic PAH (pyrene) or detoxification pathways (3-OHBaP for BaP), although new biomarkers reflecting the genotoxic pathway of BaP (TetraolBaP) are now available. There is thus a need for identifying more relevant biomarkers of exposure / effect, and for a better understanding of the biological consequences resulting from PAH exposures as well as the associated metabolic pathways involved.

The objectives of the project are :

  • To better understand and characterize molecular, metabolic and genotoxic impacts resulting from exposure to PAHs and to link such impacts with biological levels of various PAH metabolites,
  • To study the influence of BaP metabolism (genotoxic versus detoxication pathway) on the differential expression of metabolites / proteins and on genotoxicity endpoints in order to get relevant data for deriving new biological limit values,
  • To elucidate the associations between omics deregulations due to PAH exposures and activated metabolic pathways, in order to define candidate effect biomarkers for human biomonitoring.

The originalities of the project are the following. First, this is a human study performed in real occupational settings on workers exposed to representative PAH mixtures. It is a multidisciplinary approach simultaneously combining up-to-date biomonitoring, omics and cytogenetics analyses, that will give insight into a comprehensive view of metabolic reactions and protein expressions following occupational exposure to PAH mixtures, and allow the identification of the biological processes involved. Carcinogenic BaP metabolites (Tetraol-BaP and 3-OHBaP) will be simultaneously analyzed in order to compare the two main metabolic pathways of BaP.

The main steps of the projects will be :

  • Recruitment of 100 workers differentially exposed to PAH mixtures sampled across two time periods (after weeks of exposure and following 3 weeks without occupational exposure),
  • Recording of relevant data (work characteristics, jobs / tasks, working experience, number of years of exposure, smoking habits, nutritional intake, co-morbidity),
  • Toxicological analyses (LC-Fluorescence and GC-MS-MS) of urinary metabolites of several gaseous and particulate PAHs (Naphtalene, Fluorene, Phenanthrene, Pyrene, BaP, BeP, Chrysene, Benzo(b)Fluoranthene, Benzo(k)Fluoranthene, Benzo(a)Anthracene),
  • Proteomics analyses on blood samples through an enrichment approach for a bottom-up label free quantitative proteomic analysis based LC-HR-MS. Deregulated proteins (DEP) will be identified and the associated protein signature. A gene ontology (GO) analysis will define the groups of biological processes involved,
  • Untargeted Metabolomics analyses on blood samples in UHPLC-HR-MS, with unsupervised statistical analyses (Principal Component Analysis, Logistic Regressions), identification of relevant metabolites by their comparison to the Human Metabolome database, and advanced molecular networking / spectral library search of LC-MSMS data,
  • Micronuclei (MN) in buccal cells through the harvesting of buccal cells using a cytobrush, transfer to the lab in a buffer, fixing and staining, automatic counting under fluorescent light.

Study Type

Interventional

Enrollment (Anticipated)

100

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Subjects ages 18 years or more
  • Subjects occupationally exposed to PAHs since more than 3 months
  • Having signed the informed consent
  • recruited by the occupational health service

Exclusion Criteria:

  • Obesity (BMI>30)
  • Subjects suffering cancers or metabolic diseases (diabetes, dyslipidemia, amino-acid diseases, renal or hepatic impairment) at the onset of the study.
  • Subjects taking medications related to the above diseases at the onset of the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Subjects occupationally exposed to PAHs
Biological samples collected in period of exposure and after holidays

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Deregulation of blood proteins expression due to exposure to PAHs
Time Frame: up to 6 months between both periods of study
Number of proteins up or down regulated in period of exposure versus after holidays
up to 6 months between both periods of study
Deregulation of blood metabolites expression due to exposure to PAHs
Time Frame: up to 6 months between both periods of study
Number of metabolites up or down regulated in period of exposure versus after holidays
up to 6 months between both periods of study
Frequency of micronuclei measured due to exposure to PAHs
Time Frame: up to 6 months between both periods of study
Frequency of cells containing micronuclei in period of exposure versus after holidays
up to 6 months between both periods of study

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Renaud PERSOONS, University Hospital, Grenoble

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 25, 2023

Primary Completion (Anticipated)

October 1, 2025

Study Completion (Anticipated)

October 1, 2025

Study Registration Dates

First Submitted

December 23, 2022

First Submitted That Met QC Criteria

December 23, 2022

First Posted (Actual)

January 11, 2023

Study Record Updates

Last Update Posted (Actual)

April 28, 2023

Last Update Submitted That Met QC Criteria

April 27, 2023

Last Verified

April 1, 2023

More Information

Terms related to this study

Other Study ID Numbers

  • 38RC22.0219
  • 2022-A01590-43 (Other Identifier: IDRCB)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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