Electrostatic potential difference between tumor and paratumor regulates cancer stem cell behavior and prognose tumor spread

Haoran Zhao; Weijie Zhang; Xiaowei Tang; Edgar A Galan; Yinheng Zhu; Gan Sang; Davit Khutsishvili; Honghui Zheng; Shaohua Ma

doi:10.1002/btm2.10399

Electrostatic potential difference between tumor and paratumor regulates cancer stem cell behavior and prognose tumor spread

Bioeng Transl Med. 2022 Sep 23;8(2):e10399. doi: 10.1002/btm2.10399. eCollection 2023 Mar.

Authors

Haoran Zhao^{1

2}, Weijie Zhang³, Xiaowei Tang^{1

2}, Edgar A Galan^{1

2}, Yinheng Zhu^{1

2}, Gan Sang^{1

2}, Davit Khutsishvili^{1

2}, Honghui Zheng^{1

2}, Shaohua Ma^{1

2

4}

Affiliations

¹ Tsinghua Shenzhen International Graduate School (SIGS) Tsinghua University Shenzhen China.
² Tsinghua-Berkeley Shenzhen Institute (TBSI) Shenzhen China.
³ Department of Oncology The First Affiliated Hospital, Zhengzhou University Zhengzhou China.
⁴ Shenzhen Bay Laboratory Shenzhen China.

Abstract

Tumor spread is responsible for most deaths related to cancer. Increasing the accuracy of cancer prognosis is critical to reducing the high mortality rates in cancer patients. Here, we report that the electrostatic potential difference (EPD) between tumor and its paratumor tissue is a prognostic marker for tumor spread. This finding is concluded from the patient-specific EPD values and clinical observation. The electrostatic potential values were measured on tissue cryosections from 51 patients using Kelvin probe force microscopy (KPFM). A total of ~44% (15/34) patients of V_{tumor-paratumor} > 0 were featured with tumor spread, whereas only ~18% (2/11) patients of V_{tumor-paratumor} < 0 had tumor spread. Next, we found the increased enrichment of cancer stem cells in paratumors with lower electrostatic potentials using immunofluorescence imaging, which suggested the attribution of tumor spread to the galvanotaxis of cancer stem cells (CSCs) toward lower potential. The findings were finally validated in breast and lung spheroid models composed of differentiated cancer cells and cancer stem cells at the ratio of 1:1 and embedded in Matrigel dopped with negative-, neutral- and positive-charged polymers and CSCs prefer to spread out of spheroids to lower electrostatic potential sites. This work may inspire the development of diagnostic and prognostic strategies targeting at tissue EPDs and CSCs for tumor therapy.

Keywords: cancer prognosis; cancer stem cells; electrostatic potential; paratumor; tumor; tumor spread.