Effect of scinderin expression on MEG-01 cell morphology, volume, nucleus number, and rate of proliferation.

Cells transfected with either pcDNA3 or pcDNA3-Sc were cultured for 8 days after removal of the antibiotic G 418. (A, B, E-G) Cells were then fixed and stained with Wright-Giemsa, and (A) volumes of pcDNA3 (n = 484) and pcDNA3-Sc (n = 600) transfected cells were measured (*P < .001). (B) Comparison of gated DNA distribution of 35 000 cells transfected with pcDNA3 and the same number of cells transfected with pcDNA3-Sc (clone ScI-E). Similar results were obtained with 5 other Sc expressing clones. (C) Cells cultured as indicated in (A) were tested for [³H]-thymidine incorporation and for their ability to take up [³H]serotonin. Bars represent mean ± SEM from 4 different experiments (*P < .001; **P < .01). (D) Number of cells present in cultures of MEG-01 cells (wild type) and cells transfected with either pcDNA3 or pcDNA3-Sc after 12 and 24 days in culture. Bars represent mean ± SEM from 4 experiments (*P < .001). Cells, cultured for 12 days, were also fixed and stained with Wright-Giemsa (E-G), rhodamine phalloidin, or a probe for F-actin (I), or they were immunostained with an Sc antibody (H). Cells transfected with pcDNA3 (E) showed a large single nucleus surrounded by a thin layer of cytoplasm (×400). (F) Cells expressing Sc (pcDNA3-Sc) were much larger and were multinucleated or had multilobulated nuclei, abundant cytoplasm, and numerous cytoplasmic extensions (×400). (G) Same cells at a large magnification (×1000). Distribution of Sc (H) and filamentous actin (I) in a double-stained cell (×1200). There was some degree of correlation between the distribution of the 2 markers, especially in the cytoplasmic extensions (arrowheads).