Fig. 2.

2D PAGE Western blotting analysis of depleted serum from control mice (CM), PC346 xenograft-bearing mice (PC346), and PC339 xenograft-bearing mice (PC339). Spots were detected by using a monoclonal antibody to proteasome α subunits 6, 2, 4, 5, 1, and 3. The presence of PSMA1 and PSMA3 proteasome subunits was confirmed with specific monoclonal antibodies. Strong signals are visible in the serum from both the PC346 and PC339 mice. Also faint signals were detected in the control serum because of cross-reactivity with mouse proteasome subunits, which are present under normal conditions in the mouse serum.