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Updated: Mar 26, 2026

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Inhibition of the RhoA GTPase Activity Increases Sensitivity of Melanoma Cells to UV Radiation Effects

Gisele Espinha1, Juliana Harumi Osaki1, Erico Tosoni Costa2

  • 1Laboratory of Signaling in Biomolecular Systems, Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, 05508-000 Sao Paulo, SP, Brazil.

Oxidative Medicine and Cellular Longevity
|January 30, 2016
PubMed

Insights

RhoA protein is crucial for melanoma cell survival and DNA repair following UV damage. Loss of RhoA activity increases UV sensitivity and impairs DNA repair, highlighting RhoA as a potential therapeutic target for metastatic melanoma.

Area of Science:

  • Oncology
  • Molecular Biology
  • Dermatology

Background:

  • Ultraviolet (UV) radiation induces DNA damage in melanocytes, leading to melanoma, a lethal cancer characterized by uncontrolled proliferation and migration.
  • The RhoA GTPase pathway is implicated in aggressive metastatic melanoma, regulating cell cycle and cytoskeleton remodeling.

Purpose of the Study:

  • To investigate if the RhoA pathway mediates UV-induced DNA damage, motility, proliferation, and survival in human metastatic melanoma cells.

Main Methods:

  • Generated and exposed UV-irradiated human melanoma cells with dominant-negative or constitutively active RhoA (MeWo-RhoA-N19, MeWo-RhoA-V14) to UV radiation.
  • Assessed cell migration, invasion, proliferation, survival, and DNA repair efficiency, including strand breaks and cyclobutane pyrimidine dimers (CPDs).

Main Results:

  • RhoA-deficient cells showed reduced migration and invasion, with fragmented stress fibers.
  • UV exposure drastically reduced proliferation and survival in RhoA-deficient cells compared to controls, indicating increased UV sensitivity.
  • Loss of RhoA activity impaired DNA repair, leading to elevated DNA lesions like strand breaks and CPDs.

Conclusions:

  • RhoA plays a significant role in mediating genomic stability and cellular responses to UV radiation in metastatic melanoma.
  • RhoA activity is essential for efficient DNA repair and cell survival following UV-induced damage.
  • Targeting the RhoA pathway could sensitize metastatic melanoma to genotoxic agents.

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