Figure 1

Elafin is downregulated in breast tumor specimens compared to the normal mammary epithelium. (A) Representative photomicrographs of elafin immunohistochemical (IHC) staining (using the monoclonal antibody TRAB/2 F from Hycult Biotech) in normal breast from reduction mammoplasty (i and ii), pre-invasive ductal carcinoma in situ (DCIS) (iii and iv) and invasive breast carcinoma (v and vi). (B) Frequency distribution illustrating the percentage of cases falling into each categorical score over the range 0 to 8 for normal breast tissue, DCIS, and invasive breast carcinoma. The dashed lines represent the cutoff used in this analysis, which was set at an elafin score of 6 based on consistent elafin expression in the normal breast epithelium. (C) Quantification of elafin expression in the normal mammary breast, DCIS, and invasive breast carcinoma tissue specimens: IHC-positive cases express elafin at or above the level of elafin expression in the normal breast epithelium (elafin score 6 to 8) and negative cases represent elafin downregulation compared to normal breast epithelium (elafin score 0 to 5), statistical significance determined by Fisher’s exact test.