Fig 6.

Human diploid fibroblasts and primary human epithelial cells express minimal amounts of SRp20. (A) MRC-5 and WI-38 fibroblasts express less SRp20 than U2OS and HeLa cells by Western blot analysis. Tubulin served as a control for sample loading. (B) Ectopic expression of SRp20 in WI-38 cells promotes cell growth. WI-38 cells were transfected during cell passage on days 0, 2, and 4 with 2 μg of T7-SRp20 plasmid and were counted on day 6. Shown immediately below the corresponding bar graph are cell lysates blotted with SRp20 antibody 7B4. Data are shown as means ± SE from two separate experiments, each performed in duplicate. (C) Western blot comparison of primary HFKn, HBEpiC, and HREC cells with HeLa, U2OS, CaSki, and C33A cells for SRp20 expression by Western blot. Tubulin or hnRNP K served as a control for sample loading. (D-F) Knockdown of SRp20 expression in HFKn (D), HBEpiC (E), and HREC (F) cells affects cell growth. Western blots above each bar graph show the knockdown efficiency of SRp20 by siRNA. The graph show means ± SE from at least two separate experiments, each in duplicate.