Unconjugated
Wnt proteins are a group of secreted signaling proteins, which function to regulate cell fate and pattern formation during embryogenesis. Altered expression of Wnt5a has been implicated in human carcinogenesis and tumor progression. A previous study identified that Wnt5a is overexpressed in human pancreatic cancer tissues, and that upregulated expression of Wnt5a promotes tumor cell migration and invasion. The present study investigated the role of Wnt5a in pancreatic cancer cell proliferation in vitro and in an orthotopic nude mouse model. Wnt5a cDNA or small interfering RNA were stably transfected into pancreatic cancer cells to assess cell proliferation-associated behaviors, including cell viability, colony formation and apoptosis in vitro, as well as tumor cell growth in an orthotopic nude mouse model. Western blot analysis was used to analyze the expression of Wnt signaling molecules. The data showed that upregulation of the expression of Wnt5a significantly promoted proliferation of the human pancreatic cells, but inhibited tumor cell apoptosis in vitro and promoted tumor growth in an orthotopic nude mouse model. By contrast, knockdown of the expression of Wnt5a inhibited cell growth and promoted apoptosis of the pancreatic cancer cells. The data also revealed that β-catenin mediated the effects of Wnt5a on the regulation of pancreatic cancer cell apoptosis in vitro. These results suggested that Wnt5a is involved in the modulation of pancreatic cancer cell proliferation, and that Wnt5a may be a potential target for pancreatic cancer therapy.
Previous studies have suggested that endoplasmic reticulum stress (ERS) is one of the mechanisms responsible for the pathogenesis of diabetic nephropathy (DN). Histone acetylation modification can regulate the transcription of genes and is involved in the regulation of ERS. Valproate (VPA), a nonselective histone deacetylase inhibitor, has been reported to have a protective role in kidney tissue injury, however, whether VPA can prevent DN remains to be elucidated. In the present study, it was found that VPA increases the expression of glucose-regulated protein (GRP78) and reduces the protein expression of C/EBP-homologous protein (CHOP), growth arrest and DNA-damage-inducible gene 153 and caspase-12 in a rat model of DN. VPA can reduce renal cell apoptosis and alleviate proteinuria and alterations in serum creatinine. VPA also upregulates the acetylation level of histone H4 in the promoter of GRP78 and downregulates the acetylation level of histone H4 in the promoter of CHOP. Collectively, the data indicate that VPA can relieve ERS and reduce renal cell apoptosis, and thus attenuate renal injury in a rat model of DN by regulating the acetylation level of histone H4 in ERS-associated protein promoters.