Recombinant Human Arresten and Canstatin Inhibit Angiogenic Behaviors of HUVECs via Inhibiting the PI3K/Akt Signaling Pathway

Angiogenetic inhibitors are crucial in tumor therapy, and endogenous angiogenesis inhibitors have attracted considerable attention due to their effectiveness, safety, and multi-targeting ability. Arresten and canstatin, which have anti-angiogenesis effects, are the c-terminal fragments of the alpha 1 and alpha 2 chains of type IV collagen, respectively. In this study, human arresten and canstatin were recombinantly expressed in Escherichia coli (E. coli), and their effects on the proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) were evaluated. Regarding the cell cycle distribution test and 5-ethynyl-2 '-deoxyuridine (EdU) assays, arresten and canstatin could repress the proliferation of HUVECs at a range of concentrations. Transwell assay indicated that the migration of HUVECs was significantly decreased in the presence of arresten and canstatin, while tube formation assays suggested that the total tube length and junction number of HUVECs were significantly inhibited by these two proteins; moreover, they could also reduce the expression of vascular endothelial growth factor (VEGF) and the phosphorylation levels of PI3K and Akt, which indicated that the activation of the 3-kinase/serine/threonine-kinase (PI3K/Akt) signaling pathway was inhibited. These findings may have important implications for the soluble recombinant expression of human arresten and canstatin, and for the related therapy of cancer.

Automated summary

In this study, human arresten and canstatin were successfully recombinantly expressed in Escherichia coli, and their anti-angiogenesis effects on human umbilical vein endothelial cells (HUVECs) were demonstrated. The results showed that arresten and canstatin could inhibit HUVECs proliferation, migration, and tube formation, as well as downregulate the expression of vascular endothelial growth factor (VEGF) and the phosphorylation levels of PI3K and Akt, suggesting the inhibition of the PI3K/Akt signaling pathway. These findings have important implications for the soluble recombinant expression of human arresten and canstatin, and for cancer therapy.