Fig 2: Effect of integrin avß3 blockade and ZEB1 knockdown on the SPARC-induced E-cadherin downregulation and enhanced migration (A). Representative Western blot of ZEB1, E-cadherin and SPARC in LNCaP cells transduced with a lentiviral vector carrying a short hairpin RNA against ZEB1 (shZEB1) or a scrambled sequence (shScr) (B). Quantification of the optic density of the Western blot shown in (A). Protein expression normalized to ß-actin and control cells (shSCR) (C,D). Relative expression of E-cadherin measured by RT-qPCR in LNCaP shScramble (C) and LNCaP shZEB1 cells stimulated with 1 µg/mL SPARC and 50 µM RGD for 6 h. E-cadherin expression normalized to pumilio and control cells (first column) using the ??Ct method (E,F). Transwell migration assay of LNCaP shScramble (E) and LNCaP shZEB1 (F) cells stimulated with 1 µg/mL SPARC and 50 µM RGD for 24 h (G,H). Representative images of wound healing assay of LNCaP shScramble (G) and LNCaP shZEB1 (H) cells stimulated with 1 µg/mL SPARC and 50 µM RGD for 24 h (I,J). Quantification of the percentage of the wound area covered after 24 h (B–F,I,J). Relative migrations were compared with their own control (basal condition) (B–F). Data are expressed as mean ± SD (n = 3). ns = p > 0.05; * = p = 0.05; ** = p = 0.01; *** = p = 0.001; (B)—Mann–Whitney U test; (C–F,I,J)—Kruskal–Wallis test.

Fig 3: Effect of SPARC on E-cadherin, vimentin, and ZEB1 expression in prostate cancer cells (A–C). Relative expression of SPARC, E-cadherin, and ZEB1 in the prostate cancer cell line DU145 transduced with a lentiviral vector carrying a short hairpin RNA against SPARC (shSPARC) or a scrambled sequence (shScr) (D). Relative expression of E-cadherin in the prostate cancer cell line LNCaP treated with different concentrations of SPARC protein or transduced with a lentiviral vector carrying the sequence for SPARC (SPARC_HA) (A–D). Relative expression was normalized to pumilio and control cells (first column) using the ??Ct method (E). Representative Western blot of E-cadherin and vimentin in LNCaP cells treated with 1µg/mL of SPARC protein for up to 72 h (F,G). Quantification of the optic density of the Western blot shown in (F). Expression of E-cadherin and vimentin was normalized to ß-actin (A–D,F,G). Data are expressed as mean ± SD (n = 3). ns = p > 0.05; * = p = 0.05; ** = p = 0.01; *** = p = 0.001; Kruskal–Wallis test.