Fig. 4
Induction of differentiation by PMA in Kasumi-2 cells. a: Cells were treated with 10−7 M PMA during 5 days and the expression of SERCA3, CD20, TdT, RAG-1 and CD19 was determined by Western blotting daily. Whereas CD19 is expressed in untreated cells, induction of SERCA3 and CD20 expression by PMA treatment was accompanied by the down-regulation of TdT and RAG-1. b, photographs 1 and 2: PMA treatments led to the formation of multicellular aggregates. Whereas untreated cells (Photograph 1) grew predominantly as single cells in suspension, PMA treated cells (10−8 M, 4 days) formed floating multicellular aggregates (Photograph 2; original magnification: 20x; bars: 50 μm). b, photographs 3 and 4: Induction of CD20 expression in PMA-treated Kasumi-2 cells detected by immunohistochemistry. Cytological smears of untreated (Photograph 3) and PMA-treated cells (10−8 M, 4 days, photograph 4) were stained for CD20 expression by immunohistochemistry as described in Methods. Brown staining indicates CD20 expression (original magnification: 40x; bars: 20 μm). b, photographs 5 and 6: May-Grünwald-Giemsa staining of cytological smears of untreated (photograph 5) and PMA-treated cells (10−8 M, 4 days, photograph 6). PMA treatment led greater cell size, decreased nucleocytoplasmic ratio (asterisks) and the frequent formation of bilobed, often excentral nuclei (black arrowheads) with a paranuclear halo (white arrowheads; original magnification: 40x; bars: 20 μm)