{
  "abstract": "Breast cancer remains a clinical challenge and requires novel molecular targets. Here, we identify the Cystatin SN (CST1) as a critical oncoprotein upregulated in breast cancer, where its expression correlates with poor prognosis. Functionally, CST1 promotes breast cancer cell proliferation and tumor growth in vitro and in vivo, independent of its secretion. Mechanistically, CST1 physically interacts with the magnesium transporter MAGT1 on the endoplasmic reticulum (ER) membrane, and this interaction potentiates MAGT1-mediated Mg²⁺ transport, elevating mitochondrial Mg²⁺ levels and fueling mitochondrial metabolism. We developed a cell-penetrating peptide TAT-TM4₂ which disrupts the CST1-MAGT1 interface and effectively suppresses Mg²⁺ flux, mitochondrial metabolism, and tumor growth in vivo. Our study unveils a non-canonical role for a secreted protein in regulating inter-organelle ion homeostasis to drive cancer metabolism and growth, and proposes a targeted peptide-based strategy for treating breast cancer.",
  "abstract_shown": true,
  "affiliations": [
    "Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650201, China.",
    "Kunming College of Life Sciences, University of Chinese Academy of Sciences, Kunming, 650204, Yunnan, China.",
    "Yunnan Key Laboratory of Breast Cancer Precision Medicine, School of Biomedical Engineering, Kunming Medical University, Kunming, 650500, China.",
    "Department of Breast and Thyroid Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.",
    "Yunnan Key Laboratory of Breast Cancer Precision Medicine, Yunnan Cancer Hospital, The Third Affiliated Hospital of Kunming Medical University, Peking University Cancer Hospital, Kunming, 650118, China.",
    "Department of Breast Surgery, The First Affiliated Hospital of China Medical University, Shenyang, 110001, China.",
    "Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.",
    "Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China."
  ],
  "article_type": "research support, non u.s. gov't",
  "arxiv": null,
  "author_total": 11,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Wenqiang Gan"
    },
    {
      "affs": [
        2
      ],
      "name": "Min Zheng"
    },
    {
      "affs": [
        3
      ],
      "name": "Li Liu"
    },
    {
      "affs": [
        2
      ],
      "name": "Jingwen Liao"
    },
    {
      "affs": [
        2
      ],
      "name": "Yu Zhu"
    },
    {
      "affs": [
        2
      ],
      "name": "Xiaochen Hou"
    },
    {
      "affs": [
        4
      ],
      "name": "Qunshan Liu"
    },
    {
      "affs": [
        5
      ],
      "name": "Hui Li"
    },
    {
      "affs": [
        6,
        7
      ],
      "name": "Jing Yao"
    },
    {
      "affs": [
        2
      ],
      "name": "Dewei Jiang"
    },
    {
      "affs": [
        2,
        4
      ],
      "name": "Ceshi Chen"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/56ndsa331xt0k.bib",
  "cited_by": 0,
  "doi": "10.7150/ijbs.136015",
  "fulltext_url": "https://europepmc.org/articles/PMC13685611",
  "id": "56ndsa331xt0k",
  "issns": [
    "1449-2288"
  ],
  "landing_url": "https://europepmc.org/article/MED/42910209",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1306|Cancer, Hypoxia, and Metabolism"
    ]
  ],
  "openalex": "W7214620996",
  "pdf_url": "https://europepmc.org/articles/PMC13685611?pdf=render",
  "pmcid": "PMC13685611",
  "pmid": "42910209",
  "published": "2026-09-11",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/56ndsa331xt0k.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:14Z",
      "native_id": "MED:42910209",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42910209"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:1306|Cancer, Hypoxia, and Metabolism",
      "subfield": "oncology"
    }
  ],
  "title": "CST1 Regulates ER-Mitochondrial Mg²⁺ Balance via MAGT1 to Promote Breast Cancer Metabolism and Growth.",
  "title_text": "CST1 Regulates ER-Mitochondrial Mg²⁺ Balance via MAGT1 to Promote Breast Cancer Metabolism and Growth.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:14Z",
  "url": "https://research.draconitic.com/paper/56ndsa331xt0k",
  "venue": "International journal of biological sciences",
  "versions": []
}