Dysregulated Glutamate Transporter SLC1A1 Propels Cystine Uptake via Xc- For Glutathione Synthesis in Lung Cancer

Wenzheng Guo, Kaimi Li, Beibei Sun, Dongliang Xu, Lingfeng Tong, Huijing Yin, Yueling Liao, Hongyong Song, Tong Wang, Bo Jing, Min Hu, Shuli Liu, Yanbin Kuang, Jing Ling, Qi Li, Yadi Wu, Qi Wang, Feng Yao, Binhua P. Zhou, Shu Hai LinJiong Deng

Research output: Contribution to journalArticlepeer-review

18 Scopus citations

Abstract

Cancer cells need to generate large amounts of glutathione (GSH) to buffer oxidative stress during tumor development. A rate-limiting step for GSH biosynthesis is cystine uptake via a cystine/ glutamate antiporter Xc-. Xc- is a sodium-independent antiporter passively driven by concentration gradients from extracellular cystine and intracellular glutamate across the cell membrane. Increased uptake of cystine via Xc- in cancer cells increases the level of extracellular glutamate, which would subsequently restrain cystine uptake via Xc-. Cancer cells must therefore evolve a mechanism to overcome this negative feedback regulation. In this study, we report that glutamate transporters, in particular SLC1A1, are tightly intertwined with cystine uptake and GSH biosynthesis in lung cancer cells. Dysregulated SLC1A1, a sodium-dependent glutamate carrier, actively recycled extracellular glutamate into cells, which enhanced the efficiency of cystine uptake via Xc- and GSH biosynthesis as measured by stable isotope-assisted metabolomics. Conversely, depletion of glutamate transporter SLC1A1 increased extracellular glutamate, which inhibited cystine uptake, blocked GSH synthesis, and induced oxidative stress-mediated cell death or growth inhibition. Moreover, glutamate transporters were frequently upregulated in tissue samples of patients with non–small cell lung cancer. Taken together, active uptake of glutamate via SLC1A1 propels cystine uptake via Xc- for GSH biosynthesis in lung tumorigenesis. Significance: Cellular GSH in cancer cells is not only determined by upregulated Xc- but also by dysregulated glutamate transporters, which provide additional targets for therapeutic intervention.

Original languageEnglish
Pages (from-to)552-566
Number of pages15
JournalCancer Research
Volume81
Issue number3
DOIs
StatePublished - Feb 1 2021

Bibliographical note

Funding Information:
This work was supported by grants from the National Nature Science Foundation of China 91957120, 81672911 (to S.-H. Lin), 81902338 ( to W. Guo), 81620108022, 91129303, 91729302, 81572759, and Shenzhen Municipal Government of China (KQTD20170810160226082 to J. Deng).

Funding Information:
This work was supported by grants from the National Nature Science Foundation of China 91957120, 81672911 (to S.-H. Lin), 81902338 (to W. Guo), 81620108022, 91129303, 91729302, 81572759, and Shenzhen Municipal Government of China (KQTD20170810160226082 to J. Deng).

Publisher Copyright:
©2020 American Association for Cancer Research.

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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