Rabbit Anti-Human DACT3 Polyclonal Antibody

Dact3 is a negative regulator of Wnt/beta-catenin signaling. c-Myb promotes tumor cell invasion through Wnt/beta-catenin pathway. However, the detailed mechanism by which Dact3 and c-Myb modulate the progression of non-small cell lung cancer (NSCLC) remains unclear. In this study, the expressions of Dact3 and c-Myb in 254 surgically resected NSCLC samples were detected by immunohistochemistry. We transfected Dact3 cDNA to A549 and H157 cells or siRNA-Dact3 to SPC cells and examined above effects on the activity of Wnt/beta-catenin signaling by Western blot and luciferase activity assay, in addition to cell biological behavior by Transwell and MTT assay. Dact3 expression was reduced in NSCLC tissue. Reduced Dact3 expression was correlated with lymph node metastasis and poor prognosis of NSCLC (P<0.05). In addition, Dact3 expression was negatively correlated with the c-Myb expression (R = -0.626, P<0.05). Dact3 transfection resulted in c-Myb reduced expression in NSCLC cells, as well as decreased activity of Wnt/beta-catenin signaling and reduced cell invasive and proliferative capacity. siRNA-Dact3 transfection had the opposite effect. Our results indicate that Dact3 may inhibit the malignant phenotype of NSCLC through downregulation of c-Myb.

Wnt/beta-catenin signaling plays key roles in embryonic development and tissue homeostasis. Dapper3/Dact3, one of the three members of the Dapper gene family, is transcriptionally repressed in colorectal cancer and may function as a negative regulator of Wnt/beta-catenin signaling. To investigate its physiological functions, we generated a mouse strain harboring conditional null alleles of Dapper3 (Dapper3(flox/flox)), and homozygous Dapper3-deficient (Dapper3(-)/(-)) mice were produced after crossing with EIIa-cre transgenic mice. We found that Dapper3 is not essential for mouse embryogenesis, postnatal survival, and reproduction. However, adult Dapper3(-)/(-) mice exhibited a mild reduction in body weight compared with their wild-type littermates, suggesting a functional role of Dapper3 in postnatal growth. To investigate the role of Dapper3 in renal fibrosis, we employed the unilateral ureteral obstruction model. Dapper3 mRNA expression was up-regulated in kidney after unilateral ureteral obstruction. Loss of the Dapper3 gene enhanced myofibroblast activation and extracellular matrix overproduction in the obstructed kidney. Moreover, this aggravated fibrotic phenotype was accompanied with accumulation of Dishevelled2 and beta-catenin proteins and activation of Wnt-targeted fibrotic genes. In primary renal tubular cells, Dapper3 inhibits Wnt-induced epithelial-to-mesenchymal transition. Consistently, Dapper3 interacted with and down-regulated Dishevelled2 protein and attenuated the Wnt-responsive Topflash reporter expression. These findings together suggest that Dapper3 antagonizes the fibrotic actions of Wnt signaling in kidney.