Figure 1

The expression of Ik-1 and MZF1 is decreased in NPM-ALK ⁺ T-cell lymphoma and primary tumors from patients. (A) Western blotting shows that Ik-1 levels were markedly lower in 4 NPM-ALK⁺ T-cell lymphoma cell lines than in T lymphocytes. Jurkat cells were used as a positive control. β-actin showed equal protein loading. Vertical lines have been inserted to indicate repositioned gel lanes. (B) Similarly, MZF1 levels were substantially lower in the lymphoma cell lines than in normal human T-cells. Jurkat cells served as a positive control. β-Actin demonstrated equal levels of loaded proteins. (C) The expression of Ik-1 and MZF1 is shown in 15 ALK⁺ T-cell lymphoma specimens from patients. Patient’s lysates were divided into 2 groups – 1–7 (left panel) and 8–15 (right panel) – and lysates from 2 different pools of normal human T lymphocytes (TL) were analyzed simultaneously as controls with the corresponding lysates from the patient tumors. Because the quality of the formalin-fixed and paraffin-embedded tissue sections varied significantly, β-actin showed unequal protein levels. (D) Despite apparent differences in protein levels loaded in the different lanes, densitometric analysis of the Ik-1/MZF1:β-actin ratio of the Western blot bands shown in (C) supports that the expression of Ik-1 and MZF1 was markedly reduced in 87% and 100%, respectively, of the ALK⁺ T-cell lymphoma specimens from patients compared to human TL. The Western blotting assays were performed 3 independent times with consistent results.