Heregulin-induced VEGF expression via the ErbB3 signaling pathway in colon cancer.

Background/aims: Heregulin (HRG/NRG) ligation to erbB3/4 promotes their respective heterodimerization with erbB2, and consequent erbB2 tyrosine phosphorylation. Although HRG has been shown to be expressed in a variety of cancer tissues, its expression and role in colon cancer have yet to be clarified. We therefore examined the link between the expression of these erbB receptors, and the relationship between HRG and vascular endothelial growth factor (VEGF) expression in colon cancer.

Tomoregulin ectodomain shedding by proinflammatory cytokines.

The shedding mechanism for the tomoregulin (TR) ectodomain, which contains two follistatin modules and a single epidermal growth factor (EGF)-like domain, remains unclear. Our study provides the first evidence that proinflammatory cytokines, IL-1beta and TNF-alpha, induce TR-ectodomain shedding in cultured A172 human glioma cells, without affecting TR mRNA expression. In addition, it appears that this shedding process is induced via activation of the NF-kappaB signaling pathway; with consequent increase in the production of metalloproteinases.

Irritant-induced cyclooxygenase-2 is involved in the defense mechanism of the gastric mucosa in mice.

Background: Endogenous and exogenous prostaglandins (PGs) have been shown to contribute to reducing the gastric injury caused by irritants given subsequently. The aim of this study was to clarify whether cyclooxygenase-2 (COX-2) protein induced by pretreatment was involved in the prevention of subsequent ethanol-caused gastric injury in mice.

Methods: Mice were pretreated with acidified ethanol or saline and then COX-2 protein expression in the stomach was immunohistochemically determined every 8h.