Deficiency in p53 is required for doxorubicin induced transcriptional activation of NF-кB target genes in human breast cancer.

// Alba Dalmases 1,2 , Irene Gonzalez 1,2 , Silvia Menendez 1,2 , Oriol Arpi 1,2 , Josep Maria Corominas 3 , Sonia Servitja 1,2 , Ignasi Tusquets 1,2,4 , Cristina Chamizo 5 , Raul Rincon 5 , Lluis Espinosa 1 , Anna Bigas 1 , Pilar Eroles 6 , Jessica Furriol 6 , Anna Lluch 7,8 , Ana Rovira 1,2 , Joan Albanell 1,2,9 , Federico Rojo 1,5 1 Cancer Research Program, IMIM (Hospital del Mar Research Institute), Barcelona, Spain; 2 Medical Oncology Department, Hospital del Mar, Barcelona, Spain; 3 Pathology Department, Hospital del Mar, Barcelona, Spain; 4 Autonomous University of Barcelona, Spain; 5 Pathology Department, IIS-Fundacion Jimenez Diaz, Madrid, Spain; 6 Institute of Health Research INCLIVA, Valencia, Spain; 7 Oncology and Hematology Department, Hospital Clinico Universitario, Valencia, Spain; 8 Valencia Central University, Spain; 9 Universitat Pompeu Fabra, Barcelona, Spain. Correspondence: Federico Rojo, email: // Keywords : breast cancer, chemoresistance, NF-кB, p53, prognosis Received : October 31, 2013 Accepted : November 21, 2013 Published : November 23, 2013 Abstract NF-кB has been linked to doxorubicin resistance in breast cancer patients. NF-кB nuclear translocation and DNA binding in doxorubicin treated-breast cancer cells have been extensively examined; however its functional relevance at transcriptional level on NF-кB -dependent genes and the biological consequences are unclear. We studied NF-кB -dependent gene expression induced by doxorubicin in breast cancer cells and fresh human cancer specimens with different genetic backgrounds focusing on their p53 status. NF-кB –dependent signature of doxorubicin was identified by gene expression microarrays in breast cancer cells treated with doxorubicin and the IKKβ-inhibitor MLN120B, and confirmed ex vivo in human cancer samples. The association with p53 was functionally validated. Finally, NF-кB activation and p53 status was determined in a cohort of breast cancer patients treated with adjuvant doxorubicin-based chemotherapy. Doxorubicin treatment in the p53-mutated MDA-MB-231 cells resulted in NF-кB driven-gene transcription signature. Modulation of genes related with invasion, metastasis and chemoresistance ( ICAM-1 , CXCL1 , TNFAIP3 , IL8 ) were confirmed in additional doxorubicin-treated cell lines and fresh primary human breast tumors. In both systems, p53-deficient background correlated with the activation of the NF-кB –dependent signature. Furthermore, restoration of p53WT in the mutant p53 MDA-MB-231 cells impaired NF-кB driven transcription induced by doxorubicin. Moreover, a p53 deficient background and nuclear NF-кB /p65 in breast cancer patients correlated with reduced disease free-survival. This study supports that p53 deficiency is necessary for a doxorubicin driven NF-кB -response that limits doxorubicin cytotoxicity in breast cancer and is linked to an aggressive clinical behavior.