Additional file 2 of Histamine N-methyltransferase (HNMT) as a potential auxiliary biomarker for predicting adaptability to anti-HER2 drug treatment in breast cancer patients

Additional file 2: Fig. S2 IHC histo-scoring of HNMT and HER2 protein expression in human BC TMAs. (A) Representative IHC images for HNMT and HER2 tissue scoring analysis. Scale bar = 100 μm. (B) Correlation of HNMT with the HER2 tissue score in human BC TMA samples (n = 211). Nonlinear regression and Pearson correlation analysis were performed to analyze tissue scores statistically. (C) Schematic representation of IHC tissue scores from tumor histotype cohorts (HER2+, TNBC, and luminal patients). The case number axis is shown on the x-axis to identify tissue groups. Each case included 1-4 tissue cohorts in the BC tumor TMAs. Different colors are indicated in blocks based on differences in HNMT and HER2 histo-scores. (D-E) The overall survival of BC patients was analyzed using the Kaplan‒Meier method, with the patients grouped based on their HNMT mRNA expression levels (D) and the combination of HNMT and HER2 mRNA expression levels (E). (F) The inhibitory effect of the HNMT inhibitor SKF-91488 on cancer cell growth was tested in different cell lines in a dose-dependent manner. Nonlinear regression, Pearson correlation analysis (B), a log-rank test (D, E), and a two-tailed unpaired Student's t-test (F) were performed for statistical analysis.