FGF2 mediates DNA repair in epidermoid carcinoma cells exposed to ionizing radiation

Area of Science:

• Cell Biology
• Molecular Oncology

Background:

• Fibroblast growth factor 2 (FGF2) is recognized as a survival factor.
• The specific role of FGF2 in DNA repair mechanisms remains largely uncharacterized.

Purpose of the Study:

• To investigate the potential role of FGF2 in DNA repair processes within epidermoid carcinoma cells.
• To compare DNA repair capabilities between cancer stem-like cells and the main cell population.

Main Methods:

• Isolation of side population (SP) cells with cancer stem cell-like properties and main population (MP) cells from human A431 squamous carcinoma cells.
• Assessment of radiation-induced DNA damage and repair using the alkaline comet assay.
• Quantification of FGF2 expression via enzyme-linked immunosorbent assay (ELISA).

Main Results:

• SP cells demonstrated rapid repair of radiation-induced DNA damage and possessed high constitutive nuclear FGF2 levels.
• Blocking FGF2 signaling significantly impaired the rapid DNA repair observed in SP cells.
• MP cells exhibited slower DNA repair associated with low basal FGF2 expression, which was accelerated by exogenous FGF2 addition.
• Irradiated SP cells secreted FGF2, while MP cells did not.

Conclusions:

• FGF2 plays a crucial role in mediating DNA repair in epidermoid carcinoma cells.
• Carcinoma stem cells are intrinsically primed for rapid DNA repair due to high constitutive nuclear FGF2.
• The lower repair rate in the main cell population, characterized by low FGF2, can be enhanced by exogenous FGF2.