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Cell Population Analyses During Skin Carcinogenesis
06:53

Cell Population Analyses During Skin Carcinogenesis

Published on: August 21, 2013

Mek1/2 gene dosage determines tissue response to oncogenic Ras signaling in the skin

F A Scholl1, P A Dumesic, D I Barragan

  • 1Department of Dermatology, Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.

Oncogene
|February 10, 2009
PubMed

Insights

Oncogenic Ras signaling in skin cancer relies on the Erk1/2 MAPK pathway. Complete deletion of Mek1/2 MAPKKs abolished Ras effects, showing a gene dosage-dependent requirement for this cascade.

Area of Science:

  • Oncology
  • Molecular Biology
  • Dermatology

Background:

  • Ras genes are frequently mutated in human cancers, particularly skin cancers.
  • Oncogenic Ras activates multiple downstream pathways, including Erk1/2 MAPK, PI3K, and RalGEF.
  • In skin, oncogenic Ras promotes hyperplasia and hinders differentiation, hallmarks of squamous cell carcinoma.

Purpose of the Study:

  • To investigate the specific role of Mek1 and Mek2 MAPKKs in mediating oncogenic Ras signaling in the epidermis.
  • To determine the downstream effector pathways essential for oncogenic Ras-induced effects in skin.

Main Methods:

  • Utilized murine models with conditionally active oncogenic Ras.
  • Examined the effects of individual and combined deletions of Mek1 and Mek2 MAPKK alleles.
  • Assessed epidermal response, including proliferation and differentiation, to oncogenic Ras activation.

Main Results:

  • Deletion of either Mek1 or Mek2 alone did not impair the epidermal response to oncogenic Ras.
  • Combined deletion of all Mek1 and Mek2 alleles completely abolished Ras-driven effects.
  • Partial deletion of Mek1/2 alleles resulted in intermediate responsiveness, indicating a gene dosage effect.

Conclusions:

  • The Erk1/2 MAPK cascade, specifically at the Mek1/2 MAPKK level, is crucial for oncogenic Ras signaling in the epidermis.
  • Oncogenic Ras-induced proliferation and differentiation changes in skin are dependent on the gene dosage of Mek1/2.
  • These findings highlight the critical role of the Mek1/2-Erk1/2 pathway in Ras-driven skin carcinogenesis.

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