Secretory High-Mobility Group Box 1 Protein Affects Regulatory T Cell Differentiation in Neuroblastoma Microenvironment In Vitro

Figure 3

Protein bioinformatics and validation of HMGB1 expression. (a) A self-organized heatmap shows the relative expressional data of 29 significantly altered proteins (labeled by gene name with spot ID) in the secretomes of SK-N-SH (SH) versus SH-N-AS (AS) (n=5 per group). (b) STRING protein network with GO-cellular component analysis showed that 24 out of 29 proteins (colored nodes) were annotated as proteins in extracellular compartments (details in Supplementary Table 2). Gray nodes represented nonsecretory proteins. (c) Panther protein classification suggested that only 2 altered proteins functioned as the signaling molecules, in which one of them was HMGB1 (details in Supplementary Table 3). (d) David annotation of GO-term biological process showed that HMGB1 play multifunctional roles, one of which may involve in the regulation of T cell response to tumor cells (details in Supplementary Table 4). (e) HMGB1 levels in the SK-N-SH (SH) and SK-N-AS (AS) secretomes were validated by Western blot analysis in duplicate. GAPDH served as a loading control.