Fig. 7.

Elevated t-DARPP protein expression positively correlates with tumor (T) staging score in lung adenocarcinoma patients. a Immunohistochemistry was performed on human NSCLC serially sectioned specimens using an N-terminal DARPP-32 antibody to exclusively detect DARPP-32 and a C-terminal DARPP-32 antibody to detect both DARPP-32 and t-DARPP. Scale bar, 50 μm. b Differential immunohistochemistry was used to quantify t-DARPP protein expression in 62 human lung cancer tissue samples. Each tissue was scored based on the percentage of tumor cells stained positive multiplied by the staining intensity (i.e. 0= none, 1= weak, 2= moderate, 3= strong expression) to yield an immune reactive (IR) score. The IR score for t-DARPP protein expression was calculated by subtracting the IR score of DARPP-32 (detected with N-terminal antibody) from the IR score of both DARPP-32 isoforms (detected with C-terminal antibody). Each point on the graph represents an individual tissue. Error bars indicate SEM. The P-value has been calculated using one-way ANOVA followed by Dunnett’s test for multiple comparison.