Conclusion
Collectively, up-regulation of Cosmc potentially impedes BC growth and metastasis by modulating the balance between Tn and T glycans.
Methods
BC cell lines with different molecular types were transduced with shRNA targeting Cosmc or, Cosmc overexpression plasmid in order to explore the role of Cosmc in cell proliferation, migration, invasion, and apoptosis. The protein levels of Tn, T, Cosmc, proliferation-related factors (Ki67 and PCNA) and apoptosis-related factors (Bax and Bad) in BC cell lines were determined by Western blot analyses. Finally, the role of Cosmc was substantiated through in vivo experiments.
Results
Cosmc was down-regulated in different subtypes of BC cell lines compared with normal control cells. Overexpression of Cosmc suppressed the proliferation, migration, and invasion, yet promoted the apoptosis of BC cells, as reflected by in vitro experiments. Additionally, in vivo tumor xenografts in nude mice showed that ectopic overexpression of Cosmc inhibited the tumor growth of BC cells. Consequently, the levels of proliferation-related factors and Tn antigen were decreased, while those of apoptosis-related factors and T antigen were increased in BC cells. This observation was confirmed in vivo in xenograft tumors.