Erbin Inhibited Angiogenesis in Vitro with the Inhibition on the STAT3 Pathway in Breast Cancer Cells

Angiogenesis plays an important role in progression of tumors including breast cancer, which accounts for the vast majority of women's malignant tumors globally, to meet the excessive requirement of oxygen and nutrition for growth, metastasis, and invasion of the tumor. Therefore, targeting tumor angiogenesis has turned into a significant target for cancer therapy. Erbin has a significant effect on the initiation and progression of cancer, including breast cancer, but its role in inhibiting vascular endothelial cell proliferation and angiogenesis by breast cancer cells remains unclear.

In this study, human SKBR3 and MCF-7 breast cancer cells were used and transfected with the plasmid and siRNA for overexpression and silence of Erbin, respectively. Western blot, qRT-PCR, CLEIA, CCK-8 and Matrigel Tube Formation Assay were used for the proteins detection, mRNAs detection, detection of VEGF in the culture supernatants, detection of cell proliferation and detection of the angiogenic ability of HUVECs in vitro, respectively.

It was shown that the expression of both Erbin protein and mRNA in SKBR3 cells was lower compared to that in MCF-7 cells (p < 0.05). While the expression of VEGF protein was higher in SKBR3 cells than that in MCF-7 cells (p < 0.05). Furthermore, the VEGF protein and mRNA in the cells, VEGF protein in the culture supernatant, HUVEC proliferation in the conditioned medium at 16 h and 24h, the total length of tube formation in the conditioned medium, and pSTAT3 protein in the cells, were downregulated by transfection of Erbin gene in SKBR3 cells and upregulated (excluding HUVEC proliferation at 16 h) by transfection of Erbin siRNA in MCF-7 cells compared with their NC cells (p < 0.05).

It can be concluded that Erbin, with inhibiting the STAT3 pathway, suppresses the proangiogenic effects of breast cancer cells, thereby suggesting its potential as a therapeutic target for breast cancer.