IKK-dependent activation of NF-κB contributes to myeloid and lymphoid leukemogenesis by BCR-ABL1

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1 Supplemental Figures BLOOD/2014/ IKK-dependent activation of NF-κB contributes to myeloid and lymphoid leukemogenesis by BCR-ABL1 Hsieh M-Y and Van Etten RA Supplemental Figure S1. Titers of retroviral stocks co-expressing dominant-negative inhibitors of NF-κB signaling. (A) Proviral copy number of genomic DNA from NIH 3T3 cells transduced with the indicated serial dilutions of the different retroviral stocks, assessed by Southern blotting with an ABL1 probe as described in Materials and methods. Con are DNAs from two different Ba/F3 cell clones each carrying a single BCR-ABL1 provirus, while Un is DNA from untransduced cells. (B) Proviral copy number in genomic DNA from primary mouse BM cells transduced with the indicated retroviral stocks at relative dilutions estimated from panel A to match their transduction efficiency.

2 Supplemental Figure S2. No increase in apoptosis in primary BCR-ABL1-transformed B-lymphoid progenitors co-expressing IκBαSR. Primary B-lymphoid cell cultures transformed with BCR-ABL1/GFP (n=3) or BCR-ABL1/IκBαSR (n=1) retrovirus (Figure 1E, F) or with BCR-ABL1/IKKαKM (n=2) retrovirus (Figure 4A) growing on stroma were assessed at 96h for levels of apoptosis using fluorescent SR-VAD- FMK to detect activated capases. The difference in apoptosis levels between BCR-ABL1/GFP transformed and BCR-ABL1/IKKαKM transformed B-lymphoid cells was not significant (t-test).

3 Supplemental Figure S3. Histopathological features of BCR-ABL1-induced B-ALL and CML-like MPN in the retroviral BMT model. (A) Peripheral blood smear from a moue with B-ALL induced by BCR-ABL1 (Wright/Giemsa stain, magnification 1000x). Note the leukocytosis composed of medium-sized lymphoblasts. (B) Histopathology of precursor B-cell acute leukemia/lymphoma induced by BCR-ABL1, involving a cervical lymph node (hematoxylin and eosin stain, magnification 4 00x). Note the monomorphic replacement of the node with medium-sized lymphoblasts with prominent nucleoli and scant cytoplasm. The malignant cells express CD19, CD20, B220, and BP1 by flow cytometric analysis (data not shown). (C) Peripheral blood smear from a mouse with CML-like MPN induced by BCR-ABL1 (Wright/Giemsa stain, magnification 1000x). Note the leukocytosis with maturing myeloid cells of the neutrophil lineage. (D-F) Histopathology (hematoxylin and eosin stains) of CML-like MPN, depicting spleen (D), liver (E) and lungs (F). Note the infiltration of organs with maturing myeloid and erythroid cells, and parenchymal hemorrhages in the lungs (magnification: B and C, 200x; D, 50x).

4 Supplemental Figure S4. Decreased nuclear RelA expression in leukemic cells from mice with B- ALL induced by BCR-ABL1/IκBαSR. (A) Representative confocal immunofluorescence photomicrographs of primary pleural effusion lymphoblasts from mice with B-ALL induced by BCR-ABL1/GFP and BCR- ABL1/IκBαSR retrovirus. Cells were stained with antibody against RelA (Red) and counterstained with Hoechst dye (blue) as described in Methods. Scale bars = 10 µm. (B) Quantification of nuclear RelA fluorescence intensity per cell in the populations shown in panel A, presented as mean fluorescence intensity (MFI) of nuclear RelA staining relative to cells expressing BCR-ABL1/GFP. The difference between BCR-ABL1/GFP- and BCR-ABL1/IκBαSR-expressing leukemic cells was significant (*P < , t-test).

5 Supplemental Figure S5. Co-expression of IκBαSR or kinase-inactive IKK mutants reduces the size of transformed B-lymphoid colonies induced by BCR-ABL1. BM transduced with the indicated virus was plated (2 106 cells/plate) in agarose as described in Materials and methods, and colony formation assessed 14 days later. Depicted are representative photomicrographs of the relative sizes of the colonies (grid size = 2 mm), indicated by red arrowheads.