FIGURE 1.

TGF-β-promoted cell cycle propagation and proliferation. A, influence of TGF-β on cell proliferation was assessed by incorporation of [³H]thymidine into Panc-1 and PaTu8988t cells after incubation in medium with 10 ng/μl TGF-β or without TGF-β for 24 and 48 h. Data are representative of triplicate experiments and are displayed as bars ± S.D. B, flow cytometry analysis was performed after propidium iodide (PI) staining in response to 10 ng/μl TGF-β treatment for 24 and 48 h. Cell cycle stages are illustrated in different colors: G2, S, and G1. Bars indicate mean values ± S.D. of three independent experiments. C, Western blot analysis to examine the effect of TGF-β on the expression of cell cycle regulatory genes in growth promoted cell lines. Panc-1 and PaTU8988t cells were left untreated or treated with TGF-β as indicated. Total cell lysates were then analyzed for expression of phosphorylated Smad3, D-type cyclins and their kinase partners (CdKs). Protein loading was controlled using anti-β-actin antibodies.