GD3 synthase (GD3S), the key enzyme that controls the biosynthesis of complex gangliosides, was shown to be over-expressed in Estrogen Receptor (ER)-negative breast cancer tumors, and associated with a decreased overall survival of patients.
ST8Sia I together with b- and c-series gangliosides are also over-expressed in neuroectoderm-derived malignant tumors such as melanoma, glioblastoma, neuroblastoma and in estrogen receptor (ER) negative breast cancer, where they play a role in cell proliferation, migration, adhesion and angiogenesis.
The disialoganglioside G(D3) is overexpressed in ∼50% of invasive ductal breast carcinoma, and the G(D3) synthase gene (ST8SIA1) displays higher expression among estrogen receptor-negative breast cancer tumors, associated with a decreased overall survival of breast cancer patients.