Evidence for a novel anti-apoptotic pathway in human keratinocytes involving the aryl hydrocarbon receptor, E2F1, and checkpoint kinase 1

K. Frauenstein, U. Sydlik, J. Tigges, M. Majora, C. Wiek, H. Hanenberg, J. Abel, C. Esser, E. Fritsche, J. Krutmann, T. Haarmann-Stemmann

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Exposure of keratinocytes (KC) to ultraviolet (UV) radiation results in the initiation of apoptosis, a protective mechanism that eliminates cells harboring irreparable DNA damage. Hence, a manipulation of UV-induced apoptosis may significantly influence photocarcinogenesis. We have discovered that the aryl hydrocarbon receptor (AHR), a key regulator of drug metabolism and an UVB-sensitive transcription factor, serves an anti-apoptotic function in UVB-irradiated human KC. Chemical and shRNA-mediated inhibition of AHR signaling sensitized KC to UVB-induced apoptosis by decreasing the expression of E2F1 and its target gene checkpoint kinase 1 (CHK1). The decreased expression of these cell-cycle regulators was due to an enhanced expression of p27 KIP1 and an associated decrease in phosphorylation of both cyclin-dependent kinase 2 and its substrate molecule retinoblastoma protein. The subsequent inhibition of E2F1 autoregulation and downstream CHK1 expression resulted in an enhanced susceptibility of damaged cells to undergo apoptosis. Accordingly, ectopic overexpression of either E2F1 or CHK1 in AHR-knockdown KC attenuated the observed sensitization to UVB-induced apoptosis. Using an AHR-knockout SKH-1 hairless mouse model, we next demonstrated the physiological relevance of the anti-apoptotic function of AHR. In contrast to their AHR-proficient littermates, the constitutive expression of E2F1 and CHK1 was significantly reduced in the skin of AHR-knockout mice. Accordingly, a single exposure of the animals to UVB resulted in an enhanced cleavage of caspase-3 in the skin of AHR-knockout mice. These results identify for the first time the AHR-E2F1-CHK1 axis as a novel anti-apoptotic pathway in KC, which may represent a suitable target for chemoprevention of non-melanoma skin cancer.

Original languageEnglish (US)
Pages (from-to)1425-1434
Number of pages10
JournalCell Death and Differentiation
Volume20
Issue number10
DOIs
StatePublished - Oct 2013
Externally publishedYes

Fingerprint

Aryl Hydrocarbon Receptors
Keratinocytes
Apoptosis
Knockout Mice
Cyclin-Dependent Kinase 2
Hairless Mouse
Checkpoint Kinase 1
Retinoblastoma Protein
Skin
Chemoprevention
Skin Neoplasms
Caspase 3
Small Interfering RNA
DNA Damage
Cell Cycle
Homeostasis
Transcription Factors
Phosphorylation
Radiation

Keywords

  • apoptosis
  • aryl hydrocarbon receptor
  • chemoprevention
  • skin cancer
  • UVB radiation

ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology

Cite this

Evidence for a novel anti-apoptotic pathway in human keratinocytes involving the aryl hydrocarbon receptor, E2F1, and checkpoint kinase 1. / Frauenstein, K.; Sydlik, U.; Tigges, J.; Majora, M.; Wiek, C.; Hanenberg, H.; Abel, J.; Esser, C.; Fritsche, E.; Krutmann, J.; Haarmann-Stemmann, T.

In: Cell Death and Differentiation, Vol. 20, No. 10, 10.2013, p. 1425-1434.

Research output: Contribution to journalArticle

Frauenstein, K, Sydlik, U, Tigges, J, Majora, M, Wiek, C, Hanenberg, H, Abel, J, Esser, C, Fritsche, E, Krutmann, J & Haarmann-Stemmann, T 2013, 'Evidence for a novel anti-apoptotic pathway in human keratinocytes involving the aryl hydrocarbon receptor, E2F1, and checkpoint kinase 1', Cell Death and Differentiation, vol. 20, no. 10, pp. 1425-1434. https://doi.org/10.1038/cdd.2013.102
Frauenstein, K. ; Sydlik, U. ; Tigges, J. ; Majora, M. ; Wiek, C. ; Hanenberg, H. ; Abel, J. ; Esser, C. ; Fritsche, E. ; Krutmann, J. ; Haarmann-Stemmann, T. / Evidence for a novel anti-apoptotic pathway in human keratinocytes involving the aryl hydrocarbon receptor, E2F1, and checkpoint kinase 1. In: Cell Death and Differentiation. 2013 ; Vol. 20, No. 10. pp. 1425-1434.
@article{069c2f52767546eebe5205bd041c678a,
title = "Evidence for a novel anti-apoptotic pathway in human keratinocytes involving the aryl hydrocarbon receptor, E2F1, and checkpoint kinase 1",
abstract = "Exposure of keratinocytes (KC) to ultraviolet (UV) radiation results in the initiation of apoptosis, a protective mechanism that eliminates cells harboring irreparable DNA damage. Hence, a manipulation of UV-induced apoptosis may significantly influence photocarcinogenesis. We have discovered that the aryl hydrocarbon receptor (AHR), a key regulator of drug metabolism and an UVB-sensitive transcription factor, serves an anti-apoptotic function in UVB-irradiated human KC. Chemical and shRNA-mediated inhibition of AHR signaling sensitized KC to UVB-induced apoptosis by decreasing the expression of E2F1 and its target gene checkpoint kinase 1 (CHK1). The decreased expression of these cell-cycle regulators was due to an enhanced expression of p27 KIP1 and an associated decrease in phosphorylation of both cyclin-dependent kinase 2 and its substrate molecule retinoblastoma protein. The subsequent inhibition of E2F1 autoregulation and downstream CHK1 expression resulted in an enhanced susceptibility of damaged cells to undergo apoptosis. Accordingly, ectopic overexpression of either E2F1 or CHK1 in AHR-knockdown KC attenuated the observed sensitization to UVB-induced apoptosis. Using an AHR-knockout SKH-1 hairless mouse model, we next demonstrated the physiological relevance of the anti-apoptotic function of AHR. In contrast to their AHR-proficient littermates, the constitutive expression of E2F1 and CHK1 was significantly reduced in the skin of AHR-knockout mice. Accordingly, a single exposure of the animals to UVB resulted in an enhanced cleavage of caspase-3 in the skin of AHR-knockout mice. These results identify for the first time the AHR-E2F1-CHK1 axis as a novel anti-apoptotic pathway in KC, which may represent a suitable target for chemoprevention of non-melanoma skin cancer.",
keywords = "apoptosis, aryl hydrocarbon receptor, chemoprevention, skin cancer, UVB radiation",
author = "K. Frauenstein and U. Sydlik and J. Tigges and M. Majora and C. Wiek and H. Hanenberg and J. Abel and C. Esser and E. Fritsche and J. Krutmann and T. Haarmann-Stemmann",
year = "2013",
month = "10",
doi = "10.1038/cdd.2013.102",
language = "English (US)",
volume = "20",
pages = "1425--1434",
journal = "Cell Death and Differentiation",
issn = "1350-9047",
publisher = "Nature Publishing Group",
number = "10",

}

TY - JOUR

T1 - Evidence for a novel anti-apoptotic pathway in human keratinocytes involving the aryl hydrocarbon receptor, E2F1, and checkpoint kinase 1

AU - Frauenstein, K.

AU - Sydlik, U.

AU - Tigges, J.

AU - Majora, M.

AU - Wiek, C.

AU - Hanenberg, H.

AU - Abel, J.

AU - Esser, C.

AU - Fritsche, E.

AU - Krutmann, J.

AU - Haarmann-Stemmann, T.

PY - 2013/10

Y1 - 2013/10

N2 - Exposure of keratinocytes (KC) to ultraviolet (UV) radiation results in the initiation of apoptosis, a protective mechanism that eliminates cells harboring irreparable DNA damage. Hence, a manipulation of UV-induced apoptosis may significantly influence photocarcinogenesis. We have discovered that the aryl hydrocarbon receptor (AHR), a key regulator of drug metabolism and an UVB-sensitive transcription factor, serves an anti-apoptotic function in UVB-irradiated human KC. Chemical and shRNA-mediated inhibition of AHR signaling sensitized KC to UVB-induced apoptosis by decreasing the expression of E2F1 and its target gene checkpoint kinase 1 (CHK1). The decreased expression of these cell-cycle regulators was due to an enhanced expression of p27 KIP1 and an associated decrease in phosphorylation of both cyclin-dependent kinase 2 and its substrate molecule retinoblastoma protein. The subsequent inhibition of E2F1 autoregulation and downstream CHK1 expression resulted in an enhanced susceptibility of damaged cells to undergo apoptosis. Accordingly, ectopic overexpression of either E2F1 or CHK1 in AHR-knockdown KC attenuated the observed sensitization to UVB-induced apoptosis. Using an AHR-knockout SKH-1 hairless mouse model, we next demonstrated the physiological relevance of the anti-apoptotic function of AHR. In contrast to their AHR-proficient littermates, the constitutive expression of E2F1 and CHK1 was significantly reduced in the skin of AHR-knockout mice. Accordingly, a single exposure of the animals to UVB resulted in an enhanced cleavage of caspase-3 in the skin of AHR-knockout mice. These results identify for the first time the AHR-E2F1-CHK1 axis as a novel anti-apoptotic pathway in KC, which may represent a suitable target for chemoprevention of non-melanoma skin cancer.

AB - Exposure of keratinocytes (KC) to ultraviolet (UV) radiation results in the initiation of apoptosis, a protective mechanism that eliminates cells harboring irreparable DNA damage. Hence, a manipulation of UV-induced apoptosis may significantly influence photocarcinogenesis. We have discovered that the aryl hydrocarbon receptor (AHR), a key regulator of drug metabolism and an UVB-sensitive transcription factor, serves an anti-apoptotic function in UVB-irradiated human KC. Chemical and shRNA-mediated inhibition of AHR signaling sensitized KC to UVB-induced apoptosis by decreasing the expression of E2F1 and its target gene checkpoint kinase 1 (CHK1). The decreased expression of these cell-cycle regulators was due to an enhanced expression of p27 KIP1 and an associated decrease in phosphorylation of both cyclin-dependent kinase 2 and its substrate molecule retinoblastoma protein. The subsequent inhibition of E2F1 autoregulation and downstream CHK1 expression resulted in an enhanced susceptibility of damaged cells to undergo apoptosis. Accordingly, ectopic overexpression of either E2F1 or CHK1 in AHR-knockdown KC attenuated the observed sensitization to UVB-induced apoptosis. Using an AHR-knockout SKH-1 hairless mouse model, we next demonstrated the physiological relevance of the anti-apoptotic function of AHR. In contrast to their AHR-proficient littermates, the constitutive expression of E2F1 and CHK1 was significantly reduced in the skin of AHR-knockout mice. Accordingly, a single exposure of the animals to UVB resulted in an enhanced cleavage of caspase-3 in the skin of AHR-knockout mice. These results identify for the first time the AHR-E2F1-CHK1 axis as a novel anti-apoptotic pathway in KC, which may represent a suitable target for chemoprevention of non-melanoma skin cancer.

KW - apoptosis

KW - aryl hydrocarbon receptor

KW - chemoprevention

KW - skin cancer

KW - UVB radiation

UR - http://www.scopus.com/inward/record.url?scp=84883801695&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84883801695&partnerID=8YFLogxK

U2 - 10.1038/cdd.2013.102

DO - 10.1038/cdd.2013.102

M3 - Article

C2 - 23912710

AN - SCOPUS:84883801695

VL - 20

SP - 1425

EP - 1434

JO - Cell Death and Differentiation

JF - Cell Death and Differentiation

SN - 1350-9047

IS - 10

ER -