Figure 10. IHC analysis of Syk and PLK1 in tumor tissues and ER maleate effect on human OSCC derived cells.

A. IHC studies showed no detectable expression of Syk in normal oral mucosa. In OSCC, both nuclear (N) and cytoplasmic (C) expression of Syk were increased. Positive control OSCC tissue showing Syk overexpression was included in each batch of immunostaining. Original magnification is 400x. B. IHC analysis showed no detectable expression of PLK1 in normal oral mucosa. In OSCC, both nuclear (N) and cytoplasmic (C) expression of PLK1 were increased. Positive control OSCC tissue showing PLK1 overexpression was included in each batch of immunostaining. Original magnification is 400x. C. Kaplan-Meier survival analysis of Syk. OSCC patients showing nuclear Syk overexpression (Syk positive, Nuc_score≥3) followed up over a period of up to 140 months showed a significant increase in mean disease free survival (DFS) (DFS = 41.03 months) as compared to patients who didn't show nuclear Syk positivity (Syk negative, Nuc_score<3) (DFS = 10.58 months; p = 0.017). D. Kaplan-Meier survival analysis of PLK1. Survival analysis over a period of up to 100 months showed a significant reduction in mean DFS in OSCC patients overexpressing nuclear PLK1 (PLK1 positive, Nuc_score≥3.5) (DFS =58.7 months) as compared to patients who didn't show nuclear PLK1 positivity (PLK1 negative, Nuc_score<3.5) (DFS = 89.8 months; p = 0.004). E. Human OSCC derived cells showed a dose-dependent reduction in cell survival with ER maleate treatment for 48 h. F. PLK1 mRNA level was decreased by ER maleate in a dose dependent manner (0-2 μM) and this decreasing effect was further enhanced in OSCC derived cells with treatment of CBP at 25μM by qPCR assay. The bar graph data were presented as mean ± SEM; groups denoted by different letters represent a significant difference at p < 0.05 (ANOVA followed by Fisher's LSD test).