Exogenous HMGB1 Promotes the Proliferation and Metastasis of Pancreatic Cancer Cells

Li Zhu; Shuai Ren; Marcus J Daniels; Wenli Qiu; Lian Song; Tao You; Dongqing Wang; Zhongqiu Wang

doi:10.3389/fmed.2021.756988

Exogenous HMGB1 Promotes the Proliferation and Metastasis of Pancreatic Cancer Cells

Front Med (Lausanne). 2021 Nov 3:8:756988. doi: 10.3389/fmed.2021.756988. eCollection 2021.

Authors

Li Zhu¹, Shuai Ren¹, Marcus J Daniels², Wenli Qiu¹, Lian Song³, Tao You⁴, Dongqing Wang³, Zhongqiu Wang¹

Affiliations

¹ Department of Radiology, Jiangsu Province Hospital of Chinese Medicine, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China.
² Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
³ Department of Radiology, Affiliated Hospital of Jiangsu University, Zhenjiang, China.
⁴ Department of Radiotherapy, Affiliated Hospital of Jiangsu University, Zhenjiang, China.

Abstract

Background: Exogenous HMGB1 plays a vital role in tumor recurrence, and HMGB1 is ubiquitous in the tumor microenvironment. However, the mechanism of action is still unclear. We investigated the role of exogenous HMGB1 in tumor proliferation and metastasis using human SW1990 and PANC-1 cells after radiotherapy and explored the possible molecular mechanism. Materials and Methods: Residual PANC-1 cells and SW1990 cells were isolated after radiotherapy. The supernatant after radiotherapy was collected. The relative expression of HMGB1 was evaluated by Enzyme Linked Immunosorbent Assay (ELISA). Electron microscope (EMS) was used to collect the images of pancreatic cancer cells pre and post radiotherapy treatment. The proliferation of pancreatic cancer cells which were treated with different radiation doses was measured by Carboxy Fluorescein Succinimidyl Ester (CFSE). The migration rates of pancreatic cancer cells were measured by wound healing assays. Subsequently, the expression of related proteins was detected by Western Blot. In vivo, the subcutaneous pancreatic tumor models of nude mice were established, and therapeutic capabilities were tested. Results: HMGB1 was detected in the supernatant of pancreatic cancer cells after radiotherapy. The results of CFSE showed that exogenous HMGB1 promotes the proliferation and metastasis of pancreatic cancer cells. The western blot results showed activation of p-GSK 3β and up-regulation of N-CA, Bcl-2, and Ki67 in response to HMGB1 stimulation, while E-CA expression was down-regulated in pancreatic cancer cells in response to HMGB1 stimulation. In vivo, ethyl pyruvate (EP, HMGB1 inhibitor) inhibits the growth of tumors and HMGB1 promotes the proliferation of tumors after radiation. Conclusion: Radiotherapy induces HMGB1 release into the extracellular space. Exogenous HMGB1 promotes the proliferation and metastasis of PANC-1 cells and SW1990 cells by activation of p-GSK 3β which is mediated by Wnt pathway.

Keywords: exogenous HMGB1; metastasis; pancreatic cancer; proliferation; radiotherapy.