Supplemental Table 1 Clinical characteristics of AML-M5 patients (n=60) Supplemental Table 2 Summary of abnormal cytogenetic results Supplemental Figure 1. (a) ROS levels were examined in leukemia patients. Supplemental Figure 2. Association between ELN risk and overall survival. Supplemental Figure 3. Jab1 regulates Trx expression in AML. Supplemental Figure 4. (a) Trx knockdown did not change the expression of Jab1 in AML cell lines. Supplemental Figure 5. (a) Normal HS-5 bone marrow cells were transfected with His-Jab1 for 48 h, and then plated in six-well plates for clonogenic assay in RPMI-1640 medium with 10% FBS.
ARTICLE ABSTRACT
Purpose: High levels of ROS and ineffective antioxidant systems contribute to oxidative stress, which affects the function of hematopoietic cells in acute myeloid leukemia (AML); however, the mechanisms by which ROS lead to malignant transformation in relapsed AML-M5 are not completely understood. We hypothesized that alterations in intracellular ROS would trigger AML-M5 relapse by activating the intrinsic pathway.Experimental Design: We studied ROS levels and conducted c-Jun activation domain–binding protein-1 (JAB1/COPS5) and thioredoxin (TRX) gene expression analyses with blood samples obtained from 60 matched AML-M5 patients at diagnosis and relapse and conducted mechanism studies of Jab1′s regulation of Trx in leukemia cell lines.Results: Our data showed that increased production of ROS and a low capacity of antioxidant enzymes were characteristics of AML-M5, both at diagnosis and at relapse. Consistently, increased gene expression levels of TRX and JAB1/COPS5 were associated with low overall survival rates in patients with AML-M5. In addition, stimulating AML-M5 cells with low concentrations of hydrogen peroxide led to increased Jab1 and Trx expression. Consistently, transfection of ectopic Jab1 into leukemia cells increased Trx expression, whereas silencing of Jab1 in leukemia cells reduced Trx expression. Mechanistically, Jab1 interacted with Trx and stabilized Trx protein. Moreover, Jab1 transcriptionally regulated Trx. Furthermore, depletion of Jab1 inhibited leukemia cell growth both in vitro and in vivo.Conclusions: We identified a novel Jab1–Trx axis that is a key cellular process in the pathobiologic characteristics of AML-M5. Targeting the ROS/Jab1/Trx pathway could be beneficial in the treatment of AML-M5. Clin Cancer Res; 23(15); 4450–61. ©2017 AACR.
