Toolkit/CAFLUX HepG2 reporter cell line

CAFLUX HepG2 reporter cell line

Construct Pattern·Research·Since 2025

Also known as: CAFLUX, CAFLUX HepG2 cells

Taxonomy: Mechanism Branch / Architecture. Workflows sit above the mechanism and technique branches rather than replacing them.

Summary

This study reports the construction and validation of a CAFLUX (Chemically Activated Fluorescent Expression) HepG2 reporter cell line engineered to express a histone H2B-green fluorescent protein (H2B-GFP) fusion protein under the control of a dioxin-responsive cytochrome P450 1A1 (CYP1A1) promoter.

Usefulness & Problems

Why this is useful

This is a HepG2 reporter cell line in which a dioxin-responsive CYP1A1 promoter drives H2B-GFP, producing nuclear fluorescence in response to AhR activation. The abstract presents it as a real-time reporter of AhR-mediated transcription.; real-time monitoring of AhR-mediated gene expression; toxicological evaluation; drug discovery; investigation of EV-mediated signaling in liver cancer models

Source:

This is a HepG2 reporter cell line in which a dioxin-responsive CYP1A1 promoter drives H2B-GFP, producing nuclear fluorescence in response to AhR activation. The abstract presents it as a real-time reporter of AhR-mediated transcription.

Source:

real-time monitoring of AhR-mediated gene expression

Source:

toxicological evaluation

Source:

drug discovery

Source:

investigation of EV-mediated signaling in liver cancer models

Problem solved

It provides a sensitive and reproducible live-cell readout for AhR-mediated CYP1A1 gene expression and for testing both activating toxicants and inhibitory bioactive modulators.; provides a nuclear fluorescent reporter readout for AhR-responsive CYP1A1 transcription in HepG2 cells; enables detection of both agonist-driven activation and antagonist-like suppression of reporter output

Source:

It provides a sensitive and reproducible live-cell readout for AhR-mediated CYP1A1 gene expression and for testing both activating toxicants and inhibitory bioactive modulators.

Source:

provides a nuclear fluorescent reporter readout for AhR-responsive CYP1A1 transcription in HepG2 cells

Source:

enables detection of both agonist-driven activation and antagonist-like suppression of reporter output

Problem links

enables detection of both agonist-driven activation and antagonist-like suppression of reporter output

Literature

It provides a sensitive and reproducible live-cell readout for AhR-mediated CYP1A1 gene expression and for testing both activating toxicants and inhibitory bioactive modulators.

Source:

It provides a sensitive and reproducible live-cell readout for AhR-mediated CYP1A1 gene expression and for testing both activating toxicants and inhibitory bioactive modulators.

provides a nuclear fluorescent reporter readout for AhR-responsive CYP1A1 transcription in HepG2 cells

Literature

It provides a sensitive and reproducible live-cell readout for AhR-mediated CYP1A1 gene expression and for testing both activating toxicants and inhibitory bioactive modulators.

Source:

It provides a sensitive and reproducible live-cell readout for AhR-mediated CYP1A1 gene expression and for testing both activating toxicants and inhibitory bioactive modulators.

Published Workflows

Development and Application of a CAFLUX HepG2 Reporter Cell Line for Real-Time Monitoring of AhR-Mediated CYP1A1 Gene Expression in Response to Environmental Toxicants and Bioactive Modulators.

2025

Objective: Construct and validate a stable HepG2 fluorescent reporter cell line for monitoring AhR-mediated CYP1A1 transcriptional responses to toxicants and bioactive modulators.

Why it works: The workflow links a DRE-containing CYP1A1-responsive promoter to H2B-EGFP so AhR-driven transcription produces nuclear GFP fluorescence, then validates that reporter output tracks endogenous CYP1A1 mRNA.

AhR-mediated transcriptionCYP1A1 promoter activation through dioxin-responsive elementslentiviral construct cloningviral packagingcell transductionstable clone isolation by limiting dilutionfluorescence screeningqPCR correlation analysis

Stages

  1. 1.
    Reporter construct design and cloning(library_design)

    To create the genetic reporter module that converts AhR/CYP1A1 promoter activity into nuclear GFP fluorescence.

    Selection: Design of a synthetic promoter with multiple DREs upstream of H2B-EGFP in a lentiviral vector.

  2. 2.
    Lentiviral packaging and HepG2 transduction(library_build)

    To introduce the reporter construct into HepG2 cells using lentiviral delivery.

  3. 3.
    Stable clone isolation and inducibility screening(broad_screen)

    To identify stable HepG2 clones with AhR-responsive GFP induction.

    Selection: GFP expression in response to TCDD after limiting-dilution cloning.

  4. 4.
    Reporter characterization with agonists and endogenous transcript comparison(secondary_characterization)

    To quantify reporter sensitivity and confirm that GFP output reflects endogenous CYP1A1 transcription.

    Selection: Dose-dependent nuclear GFP response to AhR agonists and correlation with endogenous CYP1A1 mRNA.

  5. 5.
    Functional modulation testing with inhibitory bioactive agents(confirmatory_validation)

    To show that the reporter can detect not only agonist activation but also suppression of AhR-driven transcription by bioactive modulators.

    Selection: Suppression of GFP fluorescence and/or CYP1A1 mRNA by curcumin or ADSC-derived EVs.

Steps

  1. 1.
    Clone DRE-H2B-EGFP reporter into pFUGWengineered reporter construct

    Create a lentiviral AhR-responsive fluorescent reporter cassette.

    The reporter construct must be defined before viral packaging and cell transduction can occur.

  2. 2.
    Package reporter construct in HEK293FT cellspackaged reporter construct

    Generate lentiviral particles for delivery into HepG2 cells.

    Packaging is required before the construct can be introduced into HepG2 cells by lentiviral transduction.

  3. 3.
    Transduce HepG2 cells with packaged reporterreporter delivery and cell line generation

    Introduce the reporter cassette into HepG2 cells to create stable reporter candidates.

    Transduction follows packaging and precedes stable clone isolation.

  4. 4.
    Obtain stable clones by limiting dilutioncandidate stable reporter clones

    Isolate stable individual reporter clones from the transduced population.

    Stable clones are needed before screening for inducible GFP response.

  5. 5.
    Screen stable clones for TCDD-inducible GFP expressionscreened reporter clones

    Identify clones with AhR-responsive reporter induction.

    Inducibility screening is performed after clone isolation to select functional reporter clones.

Taxonomy & Function

Primary hierarchy

Mechanism Branch

Architecture: A reusable architecture pattern for arranging parts into an engineered system.

Target processes

transcription

Input: Chemical

Implementation Constraints

cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: payload burdenoperating role: sensor

The system was built using a lentiviral construct cloned in pFUGW, packaged in HEK293FT cells, and used to transduce HepG2 cells, followed by limiting-dilution cloning and fluorescence-based screening.; requires lentiviral transduction and stable clone isolation; requires fluorescence readout of nuclear GFP; depends on a CYP1A1 promoter with multiple dioxin-responsive elements

The abstract does not show that the reporter directly measures all endogenous AhR outputs or that it generalizes beyond the HepG2 liver cancer cell context.; implemented in HepG2 hepatocellular carcinoma cells

Validation

Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication

Observations

successMammalian Cell Lineapplication demohumanHepG2 hepatocellular carcinoma cells

fluorescence reporter assay

Inferred from claim cl2 during normalization. CAFLUX HepG2 cells show dose-dependent nuclear GFP fluorescence in response to AhR agonists, with approximate detection limits of 0.01 pM for TCDD and 0.1 pM for benzo[a]pyrene. Derived from claim cl2. Quoted text: The resulting CAFLUX HepG2 cells exhibited dose-dependent nuclear GFP fluorescence when exposed to aryl hydrocarbon receptor (AhR) agonists, with limits of detection of approximately 0.01 pM for TCDD and 0.1 pM for benzo[a]pyrene (B[a]P)

Source:

limit of detection0.01 pMlimit of detection0.1 pM

Supporting Sources

Ranked Claims

Claim 1mechanistic correlationsupports2025Source 1needs review

Reporter GFP activity in CAFLUX HepG2 cells correlates with endogenous CYP1A1 mRNA expression, supporting that the reporter reflects native transcriptional responses.

This reporter activity correlated with endogenous CYP1A1 mRNA expression as determined by quantitative polymerase chain reaction (qPCR), confirming that GFP signals reflected native transcriptional responses.
Claim 2modulator responsesupports2025Source 1needs review

ADSC-derived extracellular vesicles reduce both GFP fluorescence and CYP1A1 mRNA levels in the CAFLUX HepG2 system, suggesting inhibition of AhR-driven transcription.

extracellular vesicles (EVs) derived from adipose-derived stem cells (ADSCs) significantly reduced both GFP fluorescence and CYP1A1 mRNA levels, suggesting an inhibitory effect on AhR-driven transcription
Claim 3modulator responsesupports2025Source 1needs review

Curcumin suppresses CAFLUX GFP expression in a concentration-dependent manner and induces apoptotic morphology at higher doses.

In functional assays, curcumin suppressed GFP expression in a concentration-dependent manner and induced apoptotic morphology at higher doses
Claim 4sensitivitysupports2025Source 1needs review

CAFLUX HepG2 cells show dose-dependent nuclear GFP fluorescence in response to AhR agonists, with approximate detection limits of 0.01 pM for TCDD and 0.1 pM for benzo[a]pyrene.

The resulting CAFLUX HepG2 cells exhibited dose-dependent nuclear GFP fluorescence when exposed to aryl hydrocarbon receptor (AhR) agonists, with limits of detection of approximately 0.01 pM for TCDD and 0.1 pM for benzo[a]pyrene (B[a]P)
limit of detection 0.01 pMlimit of detection 0.1 pM
Claim 5tool capabilitysupports2025Source 1needs review

The CAFLUX HepG2 reporter cell line enables real-time nuclear-localized monitoring of AhR-mediated CYP1A1 gene expression.

The CAFLUX HepG2 reporter system therefore provides a sensitive and reproducible platform for real-time, nuclear-localized monitoring of AhR-mediated gene expression.

Approval Evidence

1 source5 linked approval claimsfirst-pass slug caflux-hepg2-reporter-cell-line
This study reports the construction and validation of a CAFLUX (Chemically Activated Fluorescent Expression) HepG2 reporter cell line engineered to express a histone H2B-green fluorescent protein (H2B-GFP) fusion protein under the control of a dioxin-responsive cytochrome P450 1A1 (CYP1A1) promoter.

Source:

mechanistic correlationsupports

Reporter GFP activity in CAFLUX HepG2 cells correlates with endogenous CYP1A1 mRNA expression, supporting that the reporter reflects native transcriptional responses.

This reporter activity correlated with endogenous CYP1A1 mRNA expression as determined by quantitative polymerase chain reaction (qPCR), confirming that GFP signals reflected native transcriptional responses.

Source:

modulator responsesupports

ADSC-derived extracellular vesicles reduce both GFP fluorescence and CYP1A1 mRNA levels in the CAFLUX HepG2 system, suggesting inhibition of AhR-driven transcription.

extracellular vesicles (EVs) derived from adipose-derived stem cells (ADSCs) significantly reduced both GFP fluorescence and CYP1A1 mRNA levels, suggesting an inhibitory effect on AhR-driven transcription

Source:

modulator responsesupports

Curcumin suppresses CAFLUX GFP expression in a concentration-dependent manner and induces apoptotic morphology at higher doses.

In functional assays, curcumin suppressed GFP expression in a concentration-dependent manner and induced apoptotic morphology at higher doses

Source:

sensitivitysupports

CAFLUX HepG2 cells show dose-dependent nuclear GFP fluorescence in response to AhR agonists, with approximate detection limits of 0.01 pM for TCDD and 0.1 pM for benzo[a]pyrene.

The resulting CAFLUX HepG2 cells exhibited dose-dependent nuclear GFP fluorescence when exposed to aryl hydrocarbon receptor (AhR) agonists, with limits of detection of approximately 0.01 pM for TCDD and 0.1 pM for benzo[a]pyrene (B[a]P)

Source:

tool capabilitysupports

The CAFLUX HepG2 reporter cell line enables real-time nuclear-localized monitoring of AhR-mediated CYP1A1 gene expression.

The CAFLUX HepG2 reporter system therefore provides a sensitive and reproducible platform for real-time, nuclear-localized monitoring of AhR-mediated gene expression.

Source:

Comparisons

Source-stated alternatives

The web research summary identifies related AhR reporter systems such as CALUX, AZ-AHR, pGud-Luc1.1, pGL3-XRE, and XRE-H2B-eGFP as nearby alternatives or lineage comparators.

Source:

The web research summary identifies related AhR reporter systems such as CALUX, AZ-AHR, pGud-Luc1.1, pGL3-XRE, and XRE-H2B-eGFP as nearby alternatives or lineage comparators.

Source-backed strengths

sensitive; reproducible; real-time nuclear-localized readout; reporter activity correlated with endogenous CYP1A1 mRNA expression

Source:

sensitive

Source:

reproducible

Source:

real-time nuclear-localized readout

Source:

reporter activity correlated with endogenous CYP1A1 mRNA expression

Compared with cdiGEBS

CAFLUX HepG2 reporter cell line and cdiGEBS address a similar problem space because they share transcription.

Shared frame: same top-level item type; shared target processes: transcription; same primary input modality: chemical

Compared with p160 nuclear receptor coactivator family

CAFLUX HepG2 reporter cell line and p160 nuclear receptor coactivator family address a similar problem space because they share transcription.

Shared frame: same top-level item type; shared target processes: transcription; same primary input modality: chemical

Compared with Product Nkabinde

CAFLUX HepG2 reporter cell line and Product Nkabinde address a similar problem space because they share transcription.

Shared frame: same top-level item type; shared target processes: transcription; same primary input modality: chemical

Ranked Citations

  1. 1.
    StructuralSource 1MED2025Claim 1Claim 2Claim 3

    Extracted from this source document.