Cytochrome P450 (CYP) enzyme induction in vitro method using the cryopreserved human hepatocytes

Topic: Toxicokinetics

Test Method Number:

TM2009-13 (EU)

Short Name of TM:

CryoHeps

Year received:

2009

Responsible Organisation:

EURL ECVAM - European Union

Protocol(s)/SOP(s):

193

Method Description

The human cytochrome P450 (CYP) enzyme induction method assesses the potential of test chemicals to induce the activity of three CYP enzymes (CYP1A2, CYP2B6 and CYP3A sub-family) in cryopreserved primary human hepatocytes.
At the molecular level, CYP enzyme induction is a process controlled by a set of nuclear receptors associated with downstream signal transduction pathways.
Experimentally, at the end of cell exposure to the test chemical, a cocktail of three specific CYP enzymatic substrate probes is applied to the cells and CYP enzyme induction is assessed through the measurement of of the specific metabolites formation by CYP1A2, 2B6 and 3A sub-family by analytical liquid chromatography/mass spectrometry (LC/MS) technique.
The CYP enzyme induction in vitro methods (see also TM2009-14) are reliable and relevant methods for the generation of human metabolism data in animal-free testing strategies assessing adverse health effects of...

Track Approval Status

Submission
Validation
Peer-review
Recommendation
Regulatory acceptance/Standards

Submission

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Date	Stage	Comment	Documents/Links
Jan 2009	Not applicable	See Validation step.

Validation

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Date	Stage	Comment	Documents/Links
Feb 2009	Initiated	Starting of the EURL ECVAM coordinated study on CYP induction in vitro method and establishment of the Validation Management group (VMG).
Mar 2014	Finalised	Completion of the validation study with the issue of validation report.	Validation report

Peer-review

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Date	Stage	Comment	Documents/Links
Apr 2014	Initiated	Meeting of the ESAC Working Group (WG) for the review of test methods on CYP induction (ESAC WG on CYP induction).	ESAC peer review documents ESAC request
Oct 2014	Finalised	Endorsement of the WG report and the ESAC opinion on ECVAM-led validation study on two in vitro hepatic human-derived test methods for assessing induction of CYP enzymes at the 40th ESAC plenary meeting.	ESAC opinion ESAC WG report

Recommendation

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Date	Stage	Comment	Documents/Links
Jul 2014	Not applicable

Regulatory acceptance/Standards

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Date	Stage	Comment	Documents/Links
Apr 2013	Drafting of new regulatory standard/guideline	Project approved and included in the OECD test guidelines programme for the development of a test guideline on CYP enzyme induction in human-derived hepatic metabolic competent test systems.
May 2015	Stopped	Development of Test Guideline stopped. OECD decision to proceed with OECD Test Guideline development only for the Cytochrome P450 (CYP) enzyme induction <i>in vitro</i> method using cryopreserved differentiated human HepaRG<sup>TM</sup> cells (see TM2009-14).