Figure 1.

Exogenous CCN3 treatment down-regulates MC CCN2 and COL1 protein and COL1 promoter activity. Secretion of CCN2 (A) or COL1 (B) per cell in response to conditioned medium (cond)-CCN3 or purified rmCCN3 as quantified by ELISA. *P < 0.05 versus TGF-β; **P < 0.05 versus control. Box shows the range, the dot the average, and the line the median of values. The amount of CCN3 in the conditioned medium from NCI-H295R cells was predetermined by ELISA. C: Activation of COL1 promoter as measured by luciferase activity, in response to rhCCN3 at the times indicated after transfection. Each bar represents an individual treatment under the conditions indicated. The experiment was repeated with very similar results. A: The low baseline CCN2 secretion was markedly increased by TGF-β exposure and both unpCCN3 (cond. NCI) and rmNOV blocked CCN2 production in a dose-dependent manner. B: A similar effect was seen on COL1 levels. C: COL1 promoter activity was the strongest 48 hours after transfection and was greatly inhibited by CCN3.