Expression of MRJ in breast cancer cell lines and tissues. (a) Expression of mammalian relative of DnaJ (MRJ) long isoform (MRJ [L]) is significantly lower in various breast cancer cell lines as compared with that observed in RNA from normal breast. Real-time quantitative RT-PCR was used to assess expression of MRJ(L) relative to endorse control gene glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The data are represented as fold change in the abundance of the MRJ(L) transcripts using commercially available normal breast RNA as a calibrator. Each reaction was carried out in triplicate, and the experiment was repeated once with RNA from the same cell lines at a different passage. The error bars represent the standard error. (b) Expression of MRJ isoforms in various breast cancer cell lines. An equal amount of protein lysate (20 μg) was resolved on SDS-PAGE and immunoblotted for levels of MRJ isoforms. Equal loading was confirmed by comparable β-actin signal. (c) Tissue microarray staining for MRJ. A breast carcinoma progression array (CC08-00-001; developed by Cybrdi Inc.) was stained by 1:100 dilution (10 μg/ml) of DNAJB6 monoclonal antibody. Mouse IgG1 was used for the isotype background control. Photomicrographs were taken in the area of most intense and diffuse staining for MRJ. The photomicrographs are representative images showing staining patterns of MRJ. Panel 1 corresponds to cystic hyperplasia, and panel 2 corresponds to infiltrating ductal carcinoma grade III.