Expression levels of Bcl-2–related proteins and P-gp (MDR-1). (A) Expression of Bcl-2–related proteins. Western blot analysis of CEM, CD95-resistant CEM (CEM^CD95-R), DX-resistant CEM (CEM^DX-R), SHEP, and CD95-resistant SHEP (SHEP^CD95-R) cell lysates was performed using mouse anti–Bcl-2 monoclonal, rabbit anti–Bcl-x_L polyclonal, and rabbit anti-Bax polyclonal antibody and ECL. (B) Assessment of P-gp (MDR-1) expression. P-gp expression of CEM (solid line), CD95-resistant CEM (CEM^CD95-R; thin line), DX-resistant CEM cells (CEM^DX-R; broken line), SHEP (solid line), and CD95-resistant SHEP cells (SHEP^CD95-R; broken line) was determined by FACS analysis using P-gp (MDR-1) monoclonal antibody UIC2. Representative experiments of three performed are shown.