Glycolipids Recognized by A2B5 Antibody Promote Proliferation, Migration, and Clonogenicity in Glioblastoma Cells

Nathalie Baeza-Kallee (1) , Raphael Berges (1) , Aurélie Soubéran (1) , Carole Colin (1) , Emilie Denicolaï (1) , Romain Appay (1, 2) , Aurélie Tchoghandjian (1) , Dominique Figarella-Branger (1, 2)

1 INP - Institut de neurophysiopathologie
2 ACPNP - Service d'Anatomo-Cyto-Pathologie et de NeuroPathologie [Hôpital de la Timone - APHM]

A2B5+ cells isolated from human glioblastomas exhibit cancer stem cell properties. The A2B5 epitope belongs to the sialoganglioside family and is synthetized by the ST8 alpha-N-acetyl-neuraminidase α-2,8-sialyltransferase 3 (ST8SIA3) enzyme. Glycolipids represent attractive targets for solid tumors; therefore, the aim of this study was to decipher A2B5 function in glioblastomas. To this end, we developed cell lines expressing various levels of A2B5 either by genetically manipulating ST8SIA3 or by using neuraminidase. The overexpression of ST8SIA3 in low-A2B5-expressing cells resulted in a dramatic increase of A2B5 immunoreactivity. ST8SIA3 overexpression increased cell proliferation, migration, and clonogenicity in vitro and tumor growth when cells were intracranially grafted. Conversely, lentiviral ST8SIA3 inactivation in low-A2B5-expressing cells resulted in reduced proliferation, migration, and clonogenicity in vitro and extended mouse survival. Furthermore, in the shST8SIA3 cells, we found an active apoptotic phenotype. In high-A2B5-expressing cancer stem cells, lentiviral delivery of shST8SIA3 stopped cell growth. Neuraminidase treatment, which modifies the A2B5 epitope, impaired cell survival, proliferation, self-renewal, and migration. Our findings prove the crucial role of the A2B5 epitope in the promotion of proliferation, migration, clonogenicity, and tumorigenesis, pointing at A2B5 as an attractive therapeutic target for glioblastomas.

Mots clés: A2B5; ST8SIA3; glioblastoma; cancer stem cell; tumorigenicity

Domaines: Sciences du Vivant [q-bio]

Nathalie Baeza-Kallee, Raphael Berges, Aurélie Soubéran, Carole Colin, Emilie Denicolaï, et al.. Glycolipids Recognized by A2B5 Antibody Promote Proliferation, Migration, and Clonogenicity in Glioblastoma Cells. Cancers, 2019, 11 (9), pp.1267. ⟨10.3390/cancers11091267⟩. ⟨hal-02277276⟩