Priming and potentiation of DNA damage response by fibronectin in human colon cancer cells and tumor-derived myofibroblasts

Wever Olivier De , Joëlle Sobczak-Thepot (1, 2) , Vercoutter-Edouart Anne-Sophie , Michalski Jean-Claude , Ouelaa-Benslama Radia , Stupack Dwayne G. , Wang Jean Y.J. , Shahin Emami , Gespach Christian , Bracke Marc

1 SU - Sorbonne Université
2 LBD - Laboratoire de Biologie du Développement [IBPS]

We have previously shown that the genotoxin-induced apoptosis in mouse embryo fibroblasts was enhanced by the extracellular matrix protein fibronectin (FN). In the present study, we tested the hypothesis that FN regulates the DNA damage response (DDR) signaling pathways in HCT116 (p53-wt) and HT29 (p53-mut) human colon cancer cells and tumor-derived myofibroblasts. DNA damage recognition mechanisms were analyzed by immunofluorescence staining, cell cycle analysis and immunoblotting addressed at specific molecular sensors and executors involved in the DDR pathways. The results show that FN, but not collagen type IV or Matrigel, initiates and potentiates the DDR to the anticancer drug cisplatin in an α5 integrin and cell cycle-dependent manner (S and G2/M phases) in human colon cancer cells. Accordingly, we demonstrate that adhesion of HCT116 cells to FN upregulated the expression of α5 integrin FN receptors at the cell surface. These FN-induced DDR pathways include the concerted phosphorylation of histone H2AX on Ser 139 detected as nuclear foci (γ-H2AX, 15 and 25 kDa forms), of ataxia telangiectasia mutated (ATM-Ser 1981), checkpoint kinase 2 (CHK2-Thr 68 , 62 and 67 kDa) and p53-Ser 15. These FN-induced γ-H2AX signals were interrupted or attenuated by selective inhibitors acting on the DDR pathway kinases, including wortmannin (targeting the phosphatidylinositol-3-kinase-related protein kinases, PIKK), KU55933 (ATM), NU7026 (DNA-dependent protein kinase catalytic

Mots clés: p53; α5-integrins; cell cycle; human colon tumor myofibroblasts; cisplatin γ-H2AX phosphatidyl inositol-3-kinase-related protein kinases ataxia telangiectasia mutated check-point kinase 2 c-Jun-NH2-terminal kinase-2 p53 α5-integrins cell cycle human colon tumor myofibroblasts; cisplatin; γ-H2AX; phosphatidyl inositol-3-kinase-related protein kinases; ataxia telangiectasia mutated; check-point kinase 2; c-Jun-NH2-terminal kinase-2

Domaines: Sciences du Vivant [q-bio]

Wever Olivier De, Joëlle Sobczak-Thepot, Vercoutter-Edouart Anne-Sophie, Michalski Jean-Claude, Ouelaa-Benslama Radia, et al.. Priming and potentiation of DNA damage response by fibronectin in human colon cancer cells and tumor-derived myofibroblasts. International Journal of Oncology, 2011, ⟨10.3892/ijo.2011.1034⟩. ⟨hal-04040770⟩