Figure 7.

Cellular signaling in gremlin-1-silenced cells. (a) BMP-dependent reporter activity was analyzed in control and gremlin-1 siRNA-treated H2052 cells. The levels are expressed relative to control, which was set to 1. The error bars represent s.d. (n=4, *P<0.01). (b) Id1 mRNA expression levels were analyzed by quantitative RT–PCR. The levels are expressed relative to control. n=3, *P<0.05. (c) Id1 mRNA expression levels in primary mesothelioma cells. The levels are expressed relative to the expression levels in Met5A cells. (d) Cell lysates from control and gremlin-1 siRNA-treated H2052 cells were analyzed using a commercial phospho-protein array. (e) Quantification of alterations in the amounts of phospho-proteins (n=2). Changes were also verified by immunoblotting analyses of Akt (f) and ERK (g) pathway proteins. Molecular weight markers are indicated on the left. Expression levels of p21 (Cip1/Waf1), a p53 target gene, were analyzed in gremlin-1 siRNA-treated (h) and gremlin-1-transfected cells (i) by quantitative RT-PCR. The levels are expressed relative to control, which was set to 1. n=3, *P<0.05. I, inset. Gremlin-1 overexpression in H2052 and H28 cells was verified by immunoblotting using an antibody against the V5 tag.