HMGB1 modulates the balance between senescence and apoptosis in response to genotoxic stress

Abstract

High mobility group box‐1 (HMGB1) is involved in various diseases and is associated with the resistance of many types of human cancers to chemotherapy; however, its role in cancer metastasis remains unexplored. This study examined the HMGB1 status of both highly and poorly metastatic cancer cells in response to genotoxic stress. The weakly and highly metastatic mouse melanoma cell lines (B16 vs. B16‐F10), human melanoma cell lines (SK‐MEL‐28 vs. SK‐MEL‐24), colon cancer cell lines (DLD‐1 vs. LS174T), and wild‐type (WT) vs. HMGB1 knockout (KO) mouse embryonic fibroblasts (MEFs) were treated with doxorubicin (Dox) and camptothecin (CPT), and then cellular morphology, senescence‐associated β‐galactosidase staining, lactate dehydrogenase release, and caspase‐3 activation were used to assess cell fate. To investigate the role of HMGB1 in p21 expression, HMGB1 and p21 expressions were examined by Western blotting, and the HMGB1‐mediated p21 promoter luciferase assay was performed after small interfering RNA or overexpression of HMGB1 prior to Dox treatment. Although highly metastatic mouse melanoma B16‐F10 cells preferred senescence, with persistent HMGB1 expression, poorly metastatic B16 cells entered apoptosis, with decreasing HMGB1 levels via cleavage under Dox treatment. Similarly, more metastatic human melanoma SK‐MEL‐24 and human colon cancer LS174T cells underwent senescence, whereas fewer metastatic melanoma SK‐MEL‐28 and DLD‐1 cells exhibited apoptosis under Dox stimulation. In senescent B16‐F10, SK‐MEL‐24, and LS174T cells treated with Dox, p21 levels were increased by persistent HMGB1 expression. Furthermore, HMGB1 depletion caused a senescence‐apoptosis shift with p21 down‐regulation in B16‐F10 cells, and HMGB1 overexpression switched from apoptosis to senescence concomitantly with increased p21 expression in B16 cells after Dox treatment. The same effects were observed in both cell pairs of mouse melanoma and human colon cancer cells treated with CPT, another genotoxic stressor. Indeed, although WT MEF entered senescence accompanied by p21 increase, HMGB1 KO underwent apoptosis with p21 decrease by Dox treatment. In our cell model system, we demonstrated that highly metastatic cancer cells preferentially enter senescence, whereas apoptosis predominates in weakly metastatic cancer cells under genotoxic stress, which depends on the presence or absence of HMGB1, suggesting that the HMGB1‐p21 axis is required for genotoxic stress–induced senescence. These findings suggest that HMGB1 modulation of cancers with different metastatic status could be a strategy for selectively enforcing tumor suppression.—Lee, J.‐J., Park, I. H., Rhee, W. J., Kim, H. S., Shin, J.‐S. HMGB1 modulates the balance between senescence and apoptosis in response to genotoxic stress. FASEB J. 33, 10942–10953 (2019). http://www.fasebj.org

High mobility group box 1 (HMGB1): a pivotal regulator of hematopoietic malignancies

“…As an antiapoptotic protein, HMGB1 promotes chemotherapy resistance. However, as an enhancer of senescence, HMGB1 induces tumor cells to undergo an apoptosis-to-senescence shift to improve chemotherapy effectiveness [174]. This suggests that HMGB1 could be a target for selectively enforcing tumor suppression.…”

Ginsenoside Rb1 Alleviated High-Fat-Diet-Induced Hepatocytic Apoptosis via Peroxisome Proliferator-Activated Receptor γ

“…But it can cause stress when released outside the cell. In this process, it needs to go through the cytoplasm [32]. Although the effects of apoptosis on HMGB1 release are still unclear in NAFLD, extracellular HMGB1 from the nucleus via cytoplasm could lead to chronic inflammation resulting from DAMPs, like free fatty acid.…”

Synergistic Tumoricidal Effects of Alpha-Lipoic Acid and Radiotherapy on Human Breast Cancer Cells via HMGB1

“…RT is known to induce cellular senescence in tumors [13]. There is also evidence that HMGB1 is indispensable for senescence induction and p53, p38, and NF-κB activation is associated with radiation-induced senescence [14][15][16]. As shown in Fig.…”