MAPK14/p38 alpha confers irinotecan resistance to TP53-defective cells by inducing survival autophagy

作者：Paillas Salome; Causse Annick; Marzi Laetitia; De Medina Philippe; Poirot Marc; Denis Vincent; Vezzio Vie Nadia; Espert Lucile; Arzouk Hayat; Coquelle Arnaud; Martineau Pierre; Del Rio Maguy; Pattingre Sophie; Gongora Celine^*

来源：Autophagy, 2012, 8(7): 1098-1112.

DOI：10.4161/auto.20268

• MAPK14/p38
• survival autophagy
• irinotecan resistance
• colon cancer
• chemotherapy

Recently we have shown that the mitogen-activated protein kinase (MAPK) MAPK14/p38 alpha is involved in resistance of colon cancer cells to camptothecin-related drugs. Here we further investigated the cellular mechanisms involved in such drug resistance and showed that, in HCT116 human colorectal adenocarcinoma cells in which TP53 was genetically ablated (HCT116-TP53KO), overexpression of constitutively active MAPK14/p38a decreases cell sensitivity to SN-38 (the active metabolite of irinotecan), inhibits cell proliferation and induces survival-autophagy. Since autophagy is known to facilitate cancer cell resistance to chemotherapy and radiation treatment, we then investigated the relationship between MAPK14/p38 alpha, autophagy and resistance to irinotecan. We demonstrated that induction of autophagy by SN38 is dependent on MAPK14/p38 alpha activation. Finally, we showed that inhibition of MAPK14/p38 alpha or autophagy both sensitizes HCT116-TP53KO cells to drug therapy. Our data proved that the two effects are interrelated, since the role of autophagy in drug resistance required the MAPK14/p38 alpha. Our results highlight the existence of a new mechanism of resistance to camptothecin-related drugs: upon SN38 induction, MAPK14/p38 alpha is activated and triggers survival-promoting autophagy to protect tumor cells against the cytotoxic effects of the drug. Colon cancer cells could thus be sensitized to drug therapy by inhibiting either MAPK14/p38 or autophagy.

• 出版日期2012-7