Abstract. Smad4 has recently been identified as a tumor suppressor gene in a variety of cancers, yet the role of Smad4 in renal cell carcinoma (RCC) remained to be elusive. Therefore, the aim of the present study was to explore the function of Smad4 in RCC. The expression of Smad4 reduced the growth rate of RCC. The levels of Smad4 and forkhead box protein H1 (FOXH1) mRNA were reduced, while the levels of estrogen receptor were increased in RCC cells compared with those in human renal epithelial cells (P<0.01). Western blot analysis showed an identical trend among the three molecules. Glutathione S-transferase pull-down and immunoprecipitation assays proved the interaction between Smad4 and FOXH1. An immunofluorescence assay revealed that Smad4 and FOXH1 were colocalized in the nuclei of RCC cells. Smad4 interacts with Smad2 and migrates into the nucleus, where it interacts with FOXH1 to repress the protein expression of estrogen receptor. These results indicate that Smad4 acts as a tumor suppressor by activating FOXH1, and then suppressing the expression of estrogen receptor, in addition to tumor migration and invasion. Hence, Smad4 should be investigated as a potential target for the treatment for RCC.
The triazenide, 1-[(2-carboxyethyl)benzene]-3-[2-pyridine]triazene (HL), has been synthesized. In the presence of Et 3 N, the reaction of HL with Cu(OAc) 2 ÁH 2 O or CuCl 2 Á2H 2 O gives the tetranuclear copper(II) complexes {Cu 4 (L) 2 (l 2 -OH) 2 (OAc) 4 } 1 and {Cu 4 L 4 (l 4 -O)Cl 2 } 2, respectively. The X-ray crystal structures of both complexes have been obtained. Magnetic studies indicate significant antiferromagnetic coupling between the copper(II) centers for both complexes, with coupling constants (J) of -493.4 cm -1 for 1 and -165 cm -1 for 2.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.