Abstract 2502: The role of high mobility group box-1 protein (HMGB1) in the microenvironment of non-small cell lung cancer

Abstract

Abstract Introduction: The tumor microenvironment (TME) is critical in determining tumor development and progression. Among stromal cells in TME, cancer associated fibroblasts (CAFs) play a central role and are involved in various signals through their interaction with cancer cells in most solid tumors, leading to cancer progression and acquisition of drug resistance. Under these TME conditions, tumor cell death such as necrosis occurs, which in turn, results in the ectopic release of bioactive molecules collectively termed as damage-associated molecular patterns (DAMPs), which has been reported to play an important role in cancer progression. The purpose of this study is to clarify the effects of cancer cell-derived HMGB1, a representative DAMPs, on CAFs and to investigate whether it could be a potential therapeutic target. Methods: We established CAFs from resected non-small cell lung cancer (NSCLC) specimens and investigated the biological activity of HMGB1 on CAFs using in vitro co-culture models with NSCLC cell lines. Furthermore, we assessed the therapeutic efficacy of targeting cancer cell-derived HMGB1 using anti-HMGB1 neutralizing antibody. Results: Intracellular HMGB1 was expressed more in NSCLC cells than in normal bronchial epithelial cells and CAFs, and released from cancer cells extracellularly upon treatment with anticancer drugs. The stimulation with recombinant HMGB1 promoted the proliferation of CAFs in a dose-dependent manner, but not lung cancer cells. Co-culture with CAFs promoted cancer cells’ migratory ability and drug resistance, and stimulation with recombinant HMGB1 further enhanced these promoting effects, while administration of anti-HMGB1 neutralizing antibody suppressed these effects. On the other hand, these inhibitory effects were not observed in the absence of CAFs, suggestingHMGB1 has effect on CAFs, but not direct on cancer cells. Conclusion: HMGB1 plays an important role in cancer progression and acquisition of therapeutic resistance by upregulating the CAFs’ proliferation and activity and could be a therapeutic target in NSCLC. Citation Format: Tomohiro Habu, Keiichi Date, Ken Suzawa, Mao Yoshikawa, Masayoshi Ohki, Kazuma Iwata, Naoki Matsuda, Yin Min Thu, Kazuhiko Shien, Hiromasa Yamamoto, Shinichi Toyooka. The role of high mobility group box-1 protein (HMGB1) in the microenvironment of non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2502.