Fig. 2.

TGFβ2 and GDF15 are expressed from tumor cells and function as autocrine factors. A, qRT-PCR for the expression of TGF-β2 in PCa-118b tumor and isolated PCa-118b cells using human- and mouse-specific primers showed that TGF-β2 is mainly expressed from PCa-118b cells. B, qRT-PCR for the expression of TGF-β1, β2, and β3 in isolated PCa-118b cells using human-specific primers showed that PCa-118b cells only expressed TGFβ2. C, qRT-PCR for the expression of GDF15 in PCa-118b tumor and isolated PCa-118b cells using human and mouse-specific primers showed that GDF15 is expressed from PCa-118b cells. D, qRT-PCR for the expression of GDF family genes detected only GDF15 and GDF11 messages in isolated PCa-118b cells. E, Expression of TGF-β receptors in isolated PCa-118b cells and C4–2B4, DU145, and PC3-mm2 PCa cell lines. F, Inhibition of Smad3 phosphorylation by LDN193189, an inhibitor of BMP type 1 receptors, and by TGFβ receptor inhibitors SD208 and GW788388 (left panel). The averages of pSMAD3 to total SMAD3 ratio from two experiments are shown (right panel). *, p < 0.05