CENP-U function on TNBC.

Abstract

31 Background: Centromere protein (CENP-U) gene, as an important constitutive kinetochorecomponent, plays significant roles in cell caryomitosis. Our previous research found that about 25% of transgenic mice with CENP-U amplified had suffered breast cancer in body surface. Also, in highly aggressive breast cancer cell lines, CENP-U presented the highest expression. Furthermore, the CENP-U protein expression obviously increased in human invasive breast carcinoma compared with the normal gland and intra-ductal tissue.Here we aimed to investigate the biological functions and potential molecular mechanism of CENP-U in breast cancer tumorigenesis. Methods: Gene knockdown was accomplished by transient transfection. In addition, cell proliferation was analyzed with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and 5-Ethynyl-2'-deoxyuridine (EdU) assay while cell apoptosis was measured by flow cytometry using an annexin V-FITC apoptosis detection kit. Then, VEGF secretion in the supernatant was detected with an enzyme-linked immunosorbent assay (ELISA). Furthermore,Vascular endothelial markers of nude mouse were discovered by immunohistochemistry. And the signaling activation in the breast cancer cells was accessed by western blot using specific antibodies. Results: We observed higher CENP-U expression in breast cancer compared to adjacent normal breast tissue, especially in TNBC.The MTT and EdU assay showed that CENP-U promoted the proliferation of the triple negative breast cancer (TNBC) cells while CENP-U downregulated promoted cell apoptosis. Furthermore, the ELISA results revealed that CENP-U significantly promoted the production and secretion of VEGF in TNBC cells. In addition, CENP-U downregulated inhibits tumor growth and angiogenesis in vivo. Importantly, CENP-U targeted HIF-1α,VEGFA and COX-2, which were shown by the specific antibodies in the western blot. Conclusions: The results showed that CENP-U influence the proliferation, apoptosis and angiogenesis especially of TNBC cells. But the affected signaling pathways require further study.