Fig. 6: PolySia and CD56 tumor cell expression in HER2 expressing tumors and correlation with patient outcomes.

A–C Analysis of CD56 expression (H-Score) in HER2 expressing tumors (n = 106) categorized by A HER2 membrane expression levels, B molecular subtype, or C ER expression. Bars indicate medians and ±SEM, p < 0.05 denotes significance. Tukey’s Test (A, B) and unpaired t-test (C). D Correlation between CD56 expression levels plotted relative to polySia expression levels for each matched tissue core. Each data point was pseudo-colored based on patient outcome (Red = Deceased, Blue = Alive). Gray Line = Regression line for all matched tissue cores. Pearson correlation test and simple linear regression test. E–H Immunohistochemical staining of polySia (top row) and CD56 (bottom row) in each panel in breast cancer tissue. Representative images are shown alongside higher magnification insets from the same core. Arrows point to clusters of cells positive for polySia and/or CD56. Representative images are shown alongside higher magnification insets from the same core. Scale bar = 200 µm (cores), or 50 µm (insets). I Kaplan–Meier curves for overall survival of individuals based on polySia and CD56 expression levels in tumor cells. Patient tumors were categorized as polySia-CD56 positive (n = 36), CD56 positive/polySia negative (n = 32), polySia positive/CD56 negative (n = 11) and polySia low/negative, CD56 low/negative (n = 27). Tumors with a H-Score > 0.4 for each marker were classified as polySia and/or CD56 positive; cut-point value was set at the median ± SEM of all values. Overall survival curve comparison: Log-rank (Mantel–Cox) test.