1. Academic Validation
  2. PUMA overexpression dissociates thioredoxin from ASK1 to activate the JNK/BCL-2/BCL-XL pathway augmenting apoptosis in ovarian cancer

PUMA overexpression dissociates thioredoxin from ASK1 to activate the JNK/BCL-2/BCL-XL pathway augmenting apoptosis in ovarian cancer

  • Biochim Biophys Acta Mol Basis Dis. 2022 Sep 17;1868(12):166553. doi: 10.1016/j.bbadis.2022.166553.
Yang Chen 1 Nanjing Li 2 Jun Yang 1 Ke Li 1 Mei Tang 1 Xinyu Zhao 1 Wenhao Guo 3 Aiping Tong 1 Chunlai Nie 1 Yong Peng 1 Zhu Yuan 4
Affiliations

Affiliations

  • 1 State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Sichuan University, 17 People's South Road, Chengdu 610041, China.
  • 2 Department of Radiation Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, China.
  • 3 Department of Abdominal Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, Sichuan Province, China.
  • 4 State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Sichuan University, 17 People's South Road, Chengdu 610041, China. Electronic address: yuanzhu@scu.edu.cn.
Abstract

ASK1-JNK signaling promotes mitochondrial dysfunction-mediated Apoptosis, but the bridge between JNK and Apoptosis is not fully understood. PUMA induces Apoptosis through Bax/Bak. Our previous study suggests a therapeutic potential of PUMA for ovarian Cancer. However, whether and how PUMA activates ASK1 remains unclear. Here, we found for the first time that PUMA activated ASK1 by dissociating thioredoxin (TRX) from ASK1, however, it neither interacted with ASK1 nor TRX. Furthermore, PUMA overexpression caused ROS release from mitochondrial. H2O2 significantly impaired the interaction of ASK1 with TRX, whereas ROS scavenger NAC effectively abrogated the H2O2 effect, partly rescued PUMA-interfered interaction of ASK1 with TRX, and also abolished ASK1 phosphorylation. Interestingly, PUMA could not impair the association of ASK1 with TRX-C32S or TRX-C35S, two TRX mutants which are no longer oxidized in response to ROS. We further showed that PUMA activated ASK1-JNK axis to phosphorylate Bcl-2 and Bcl-xL, further augmenting Apoptosis of ovarian Cancer cells. In vivo, PUMA adenovirus combined with paclitaxel significantly inhibited intrinsically cisplatin-resistant ovarian Cancer growth, and caused phosphorylation of Bcl-2 and Bcl-xL. Our results from human ovarian Cancer TMA chips also revealed a positive correlation between PUMA expression and the phosphorylation of Bcl-2 and Bcl-xL. More importantly, all patients had no distal metastasis, implying a possibly clinical significance. Collectively, our results reveal a new pro-apoptotic signal amplification mechanism for PUMA by which PUMA overexpression first induces ROS-mediated dissociation of TRX from ASK1, and then causes JNK activation-triggering Bcl-2/Bcl-xL phosphorylation, ultimately augmenting Apoptosis in ovarian Cancer.

Keywords

ASK1; JNK; Ovarian cancer; PUMA; Thioredoxin.

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