Attenuation of Soft-Tissue Sarcomas Resistance to the Cytotoxic Action of TNF-alpha by Restoring p53 Function

作者：Muret Jane^*; Hasmim Meriem; Stasik Izabela; Jalil Abdelali; Mallavialle Aude; Nanbakhsh Arash; Lacroix Ludovic; Billot Katy; Baud Veronique; Thiery Jerome; Vielh Philippe; Terrier Philippe; Wiels Joelle; Vassilev Lyubomir; Lecesne Axel; Bonvalot Sylvie; Chouaib Salem

来源：PLos One, 2012, 7(6): e38808.

DOI：10.1371/journal.pone.0038808

Background: Isolated limb perfusion with TNF-alpha and melphalan is used with remarkable efficiency to treat unresectable limb sarcomas. Here we tested the ability of TNF-alpha to directly induce apoptosis of sarcoma cells. In addition, we investigated the impact of p53 in the regulation of such effect. %26lt;br%26gt;Methodology/Principal Findings: We first analysed the ability of TNF-alpha to induce apoptosis in freshly isolated tumour cells. For this purpose, sarcoma tumours (n = 8) treated ex vivo with TNF-alpha were processed for TUNEL staining. It revealed substantial endothelial cell apoptosis and levels of tumour cell apoptosis that varied from low to high. In order to investigate the role of p53 in TNF-alpha-induced cell death, human sarcoma cell lines (n = 9) with different TP53 and MDM2 status were studied for their sensitivity to TNF-alpha. TP53(Wt) cell lines were sensitive to TNF-alpha unless MDM2 was over-expressed. However, TP53(Mut) and TP53(Null) cell lines were resistant. TP53 suppression in TP53(Wt) cell lines abrogated TNF-alpha sensitivity and TP53 overexpression in TP53(Null) cell lines restored it. The use of small molecules that restore p53 activity, such as CP-31398 or Nutlin-3a, in association with TNF-alpha, potentiated the cell death of respectively TP53(Mut) and TP53(Wt) /MDM2(Ampl). In particular, CP-31398 was able to induce p53 as well as some of its apoptotic target genes in TP53(Mut) cells. In TP53(Wt)/MDM2(Ampl) cells, Nutlin-3a effects were associated with a decrease of TNF-alpha-induced NF-kappa B-DNA binding and correlated with a differential regulation of pro- and anti-apoptotic genes such as TP53BP2, GADD45, TGF-beta 1 and FAIM. %26lt;br%26gt;Conclusion/Significance: More effective therapeutic approaches are critically needed for the treatment of unresectable limb sarcomas. Our results show that restoring p53 activity in sarcoma cells correlated with increased sensitivity to TNF-alpha, suggesting that this strategy may be an important determinant of TNF-alpha-based sarcomas treatment.

• 出版日期2012-6-18