Attenuation of TNFSF10/TRAIL-induced apoptosis by an autophagic survival pathway involving TRAF2-and RIPK1/RIP1-mediated MAPK8/JNK activation
AUTOPHAGY
Authors: He, Weiyang; Wang, Qiong; Xu, Jennings; Xu, Xiuling; Padilla, Mabel T.; Ren, Guosheng; Gou, Xin; Lin, Yong
Abstract
Although it is known that tumor necrosis factor-related apoptosis-inducing ligand (TNFSF10/TRAIL) induces autophagy, the mechanism by which autophagy is activated by TNFSF10 is still elusive. In this report, we show evidence that TRAF2- and RIPK1-mediated MAPK8/JNK activation is required for TNFSF10-induced cytoprotective autophagy. TNFSF10 activated autophagy rapidly in cancer cell lines derived from lung, bladder and prostate tumors. Blocking autophagy with either pharmacological inhibitors or siRNAs targeting the key autophagy factors BECN1/Beclin 1 or ATG7 effectively increased TNFSF10-induced apoptotic cytotoxicity, substantiating a cytoprotective role for TNFSF10-induced autophagy. Blocking MAPK8 but not NFkB effectively blocked autophagy, suggesting that MAPK8 is the main pathway for TNFSF10-induced autophagy. In addition, blocking MAPK8 effectively inhibited degradation of BCL2L1/Bcl-xL and reduction of the autophagy-suppressing BCL2L1-BECN1complex. Knockdown of TRAF2 or RIPK1 effectively suppressed TNFSF10-induced MAPK8 activation and autophagy. Furthermore, suppressing autophagy inhibited expression of antiapoptosis factors BIRC2/cIAP1, BIRC3/cIAP2, XIAP and CFLAR/c-FLIP and increased the formation of TNFSF10-induced death-inducing signaling complex (DISC). These results reveal a critical role for the MAPK8 activation pathway through TRAF2 and RIPK1 for TNFSF10-induced autophagy that blunts apoptosis in cancer cells. Thus, suppression of MAPK8-mediated autophagy could be utilized for sensitizing cancer cells to therapy with TNFSF10.
Multidimensional integrative analysis uncovers driver candidates and biomarkers in penile carcinoma
SCIENTIFIC REPORTS
Authors: Marchi, Fabio Albuquerque; Martins, David Correa; Barros-Filho, Mateus Camargo; Kuasne, Hellen; Busso Lopes, Ariane Fidelis; Brentani, Helena; Souza Trindade Filho, Jose Carlos; Guimaraes, Gustavo Cardoso; Faria, Eliney F.; Scapulatempo-Neto, Cristovam; Lopes, Ademar; Rogatto, Silvia Regina
Abstract
Molecular data generation and their combination in penile carcinomas (PeCa), a significant public health problem in poor and underdeveloped countries, remain virtually unexplored. An integrative methodology combining genome-wide copy number alteration, DNA methylation, miRNA and mRNA expression analysis was performed in a set of 20 usual PeCa. The well-ranked 16 driver candidates harboring genomic alterations and regulated by a set of miRNAs, including hsa-miR-31, hsa-miR-34a and hsa-miR-130b, were significantly associated with over-represented pathways in cancer, such as immune-inflammatory system, apoptosis and cell cycle. Modules of co-expressed genes generated from expression matrix were associated with driver candidates and classified according to the over-representation of passengers, thus suggesting an alteration of the pathway dynamics during the carcinogenesis. This association resulted in 10 top driver candidates (AR, BIRC5, DNMT3B, ERBB4, FGFR1, PML, PPARG, RB1, TNFSF10 and STAT1) selected and confirmed as altered in an independent set of 33 PeCa samples. In addition to the potential driver genes herein described, shorter overall survival was associated with BIRC5 and DNMT3B overexpression (log-rank test, P = 0.026 and P = 0.002, respectively) highlighting its potential as novel prognostic marker for penile cancer.