1. Supplementary Fig. 1. Enlarged images of cellular structures in 3D cultures. Spheroids (A) and filamentous outgrowths (B) in presence of 50 ng/ml BMP7 are illustrated, size bar: 50μm

3. Supplementary Fig. 2- EMT induction and inhibition by noggin, BMP antagonist is responsive to the concentration of BMP7 or noggin. (A) Higher percentage of cells displayed morphological conversion of EMT in 2D culture after 6 days of BMP treatment. (B) The use of noggin counteracted BMP7 effect on EMT induction. (C) Recombinant noggin in culture media altered fibroblastoid morphology of PC-3 cells with stable overexpression of BMP7.

4. Supplementary Fig. 3- Morphology of various prostate cancer cells in 3D culture. Non-neoplastic BPH1, DU145 that was derived from brain metastasis of prostate tumor, LNCaP that was established from lymph node metastasis, and C4-2B, which is a LNCaP derivative that was selected for bone metastasis in murine system, were tested. Androgen-dependent LNCaP cells did not form multicellular structure, while C4-2B and DU145 cell line developed spheroids structure. BPH1 displayed mixed morphology of spheroids and grape-shaped sheets of cells. There was no difference in morphology between BMP7-treated cells and cells in low serum culture, except that single cells were observed apart from spheroids in C4-2B cells in BMP supplemented media. The efficiencies of spheroid formation were similar among prostatic cell lines tested and cell proliferation was not significantly affected by low serum stress as well.

5. Supplementary Fig. 4. Counts of migratory cells in the scratch assays. (A) PC-3 cells gained increased mobility with BMP7 treatment. (B) LY294002, PI3K inhibitor decreased cell migration induced by BMP7. (C) Chemical inhibition of MEK also compromised cell motility. In A, p<0.05 when the effect was determined at 48 hr with 50 ng/ ml BMP7 compared to 0.5% serum; similarly p<0.05, was obtained in B and C at 48 hr with 50 ng/ ml BMP7 +/- the inhibitors.