High-mobility group box 1 protein activating nuclear factor-B to upregulate vascular endothelial growth factor C is involved in lymphangiogenesis and lymphatic node metastasis in colon cancer

Objectives To investigate the roles of high-mobility group box 1 (HMGB1) protein in lymphangiogenesis and lymphatic node metastasis in colon cancer. Methods Archival tumour specimens from patients with colon cancer were analysed in this retrospective immunohistochemical study. HMGB1, vascular endothelial growth factor C (VEGF-C) and podoplanin protein levels were analysed immunohistochemically. Invitro studies using the colon cancer cell line HCT116 were also undertaken to investigate the relationship between HMGB1, VEGF-C and nuclear factor (NF)-B. Results Specimens from 70 patients with colon cancer were reviewed. The presence of positive HMGB1 immunohistochemical staining significantly correlated with lymphatic microvessel density, lymph node metastasis and VEGF-C immunohistochemical staining in colon cancer specimens. The presence of positive VEGF-C immunohistochemical staining significantly correlated with lymph node metastasis. The invitro studies demonstrated that HMGB1 upregulated VEGF-C mRNA and protein in a dose-dependent manner in HCT116 cells, and that this was mediated via NF-B. Conclusions HMGB1 immunohistochemical staining was significantly associated with lymphangiogenesis and lymphatic node metastasis in colon cancer. There was evidence that HMGB1 upregulates VEGF-C by activating NF-B in a colon cancer cell line.