Nonionotropic action of an acid-sensing ion channel inhibits leukemogenesis in the acidic bone marrow niche

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Abstract

The metabolic microenvironment plays important roles in tumorigenesis, but how leukemia-initiating cells (LICs) response to the acidic BM niche remains largely unknown. Here, we show that acid-sensing ion channel 3 (ASIC3) dramatically delays leukemogenesis. Asic3 deletion results in a remarkably enhanced self-renewal, reduced differentiation, and 9-fold greater number of murine acute myeloid LICs. We developed an ultrasensitive, ratiometric, genetically encoded fluorescent pH sensor (pHluorin3) and demonstrated that LICs prefer localizing in the endosteal niche with a neutral pH range of 7.34–7.42, but not in the vascular niche with a lower pH range of 6.89–7.22. Unexpectedly, acid-ASIC3 signaling inhibits both murine and human LIC activities in a noncanonical manner by interacting with the N-terminal of STIM1 to reduce calcium-mediated CAMK1-CREB-MEIS1-LDHA levels, without inducing cation currents. This study reveals a pathway in suppression of leukemogenesis in the acidic BM niche and provides insight into targeting LICs or other cancer stem cells through pH-dependent ASICs.

Authors

Hao Gu, Lietao Weng, Chiqi Chen, Xiaoxin Hao, Rongkun Tao, Xin Qi, Xiaoyun Lai, Ligen Liu, Tinghua Zhang, Yiming Jiang, Jin Wang, Wei-Guang Li, Zhuo Yu, Li Xie, Yaping Zhang, Xiaoxiao He, Ye Yu, Yi Yang, Dehua Wu, Yuzheng Zhao, Tian-Le Xu, Guo-Qiang Chen, Junke Zheng