STAT3/p53 pathway activation disrupts IFN-β–induced dormancy in tumor-repopulating cells
Yuying Liu, … , F. Xiao-Feng Qin, Bo Huang
Yuying Liu, … , F. Xiao-Feng Qin, Bo Huang
Published February 12, 2018
Citation Information: J Clin Invest. 2018;128(3):1057-1073. https://doi.org/10.1172/JCI96329.
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Research Article Immunology

STAT3/p53 pathway activation disrupts IFN-β–induced dormancy in tumor-repopulating cells

Abstract

Dynamic interaction with the immune system profoundly regulates tumor cell dormancy. However, it is unclear how immunological cues trigger cancer cell–intrinsic signaling pathways for entering into dormancy. Here, we show that IFN-β treatment induced tumor-repopulating cells (TRC) to enter dormancy through an indolamine 2,3-dioxygenase/kynurenine/aryl hydrocarbon receptor/p27–dependent (IDO/Kyn/AhR/p27-dependent) pathway. Strategies to block this metabolic circuitry did not relieve dormancy, but led to apoptosis of dormant TRCs in murine and human melanoma models. Specifically, blocking AhR redirected IFN-β signaling to STAT3 phosphorylation through both tyrosine and serine sites, which subsequently facilitated STAT3 nuclear translocation and subsequent binding to the p53 promoter in the nucleus. Upregulation of p53 in turn disrupted the pentose phosphate pathway, leading to excessive ROS production and dormant TRC death. Additionally, in melanoma patients, high expression of IFN-β correlated with tumor cell dormancy. Identification of this mechanism for controlling TRC dormancy by IFN-β provides deeper insights into cancer-immune interaction and potential new cancer immunotherapeutic modalities.

Authors

Yuying Liu, Jiadi Lv, Jinyan Liu, Xiaoyu Liang, Xun Jin, Jing Xie, Le Zhang, Degao Chen, Roland Fiskesund, Ke Tang, Jingwei Ma, Huafeng Zhang, Wenqian Dong, Siqi Mo, Tianzhen Zhang, Feiran Cheng, Yabo Zhou, Qingzhu Jia, Bo Zhu, Yan Kong, Jun Guo, Haizeng Zhang, Zhuo-Wei Hu, Xuetao Cao, F. Xiao-Feng Qin, Bo Huang

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Figure 6

STAT3/p53 pathway regulates IFN-β–induced TRC apoptosis.

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STAT3/p53 pathway regulates IFN-β–induced TRC apoptosis. (A) B16 TRCs we...
(A) B16 TRCs were treated with PBS, IFN-β, IFN-β/1-MT, or IFN-β/DMF for 48 hours. Cells were collected for ChIP-qPCR assay with anti–p-STAT3 (S) (left) or p-STAT3 (Y) (right) and specific primer of p27 or p53. (B) B16-p27-SGGFP and B16-p27-SGs TRCs (left) or scramble-B16 and p53-siRNAs-B16 TRCs (right) were treated with IFN-β, IFN-β/1-MT, or IFN-β/DMF for 24 hours. Cell apoptosis was determined by flow cytometry. (C) STAT3-sgRNA-B16 cells stably expressing Flag-WT-STAT3, Flag-Y705F-STAT3, or Flag-S727A-STAT3 were seeded in 3D fibrin gels and then treated with IFN-β or IFN-β/1-MT. After 48 hours of treatment, Chip-qPCR assay was performed by using anti-Flag antibody with specific primer for p27 or p53. (D and E) B16 TRCs stably overexpressing Flag-WT-STAT3, Flag-Y705F-STAT3, or Flag-S727A-STAT3 were treated with PBS, IFN-β, IFN-β/1-MT, or IFN-β/DMF for 48 or 72 hours. Cell lysates (48 hours) were extracted for Western blot (D) or (72 hours) were fixed and immunostained with anti-NR2F1 and Ki67 antibodies (E) Scale bar: 10 μm. (F) As in (D), but cell apoptosis was determined by flow cytometry. (G–I) B16 TRCs were treated with PBS, IFN-β, IFN-β/1-MT, IFN-β/DMF, IFN-β/1-MT/NAC (10 mM), or IFN-β/DMF/NAC for 48 hours. ROS levels were determined by flow cytometry (G and H). Levels of GSH, GSSG, NADP, or NADPH were measured and the ratio of GSSG/GSH or NADP/NADPH was calculated (I). (J) Activity of GPDH and 6PGDH in B16 TRCs treated with PBS, IFN-β, IFN-β/1-MT, or IFN-β/DMF for 48 hours. (K) B16 TRCs were transfected with p53-siRNA for 24 hours and then treated with IFN-β, IFN-β/1-MT, or IFN-β/DMF for 48 hours. The activity of GPDH and 6PGDH was measured. Graphs represent mean ± SEM of 3 independent experiments. *P < 0.05; **P < 0.01, by 1-way ANOVA (A–C and E–K).