Abstract: Background and purpose: High mobility group box 1 (HMGB1), which is involved in the process of DNA replication, transcription and translation, is closely related to the occurrence, development, invasion and metastasis of malignant tumors. In addition, HMGB1 is involved in the regulation of various signaling pathways of inflammation, immunity, proliferation, metastasis and autophagy. This research aimed to explore the correlation between HMGB1 and clinicopathological characteristics, immune function and neoadjuvant chemotherapy in patients with breast cancer. Methods: We enrolled a total of 120 breast cancer patients admitted to the Third Hospital of Nanchang from May 2019 to October 2020. The level of HMGB1 in sample of the core needle biopsy was determined by enzyme-linked immunosorbent assay (ELISA). IL-10 and TGF-β as the indicators of regulatory T cell (Treg) were measured. The percentages of CD3 ⁺ , CD4 ⁺ , CD8 ⁺ T lymphocytes and natural killer (NK) cells were detected by flow cytometry. The contents of immunoglobulin IgG, IgA, IgM and complement C3, C4 were determined by rate-scattering turbidimetry. The study subjects were divided into the high level group (HMGB1 ＞ 22.98 ng/mL) and the low level group (HMGB1≤22.98 ng/mL) according to the lower limit level of the 95% CI. After neoadjuvant chemotherapy, the pathological effect was evaluated according to the Miller-Payne pathological response grading standard. We analyzed the relationship between HMGB1 level and pathological efficacy. Results: HMGB1 levels were associated with breast cancer stage and lymph node metastasis (P ＜ 0.05). The level of HMGB1 was significantly correlated with Treg related IL-10 and TGF-β (r=0.734, P ＜ 0.001; r=0.686, P ＜ 0.001). CD4 ⁺ T cells/CD3 ⁺ T cells in the HMGB1 high level group were lower than in the low level group, and CD8 ⁺ T cells/CD3 ⁺ T cells were higher in the high level group than in the low level group (P ＜ 0.05). Patients with high-level HMGB1 had worse postoperative effects. Conclusion: The level of HMGB1 is related to breast cancer stage, lymph node metastasis and cellular immune function, and helps predict the efficacy of neoadjuvant chemotherapy.

Key words: High mobility group box 1, Breast cancer, Regulatory T cell, Immune function