Connexin hemichannel blockade by abEC1.1 disrupts glioblastoma progression, suppresses invasiveness, and reduces hyperexcitability in preclinical models.

BACKGROUND

Connexin (Cx) hemichannels (HCs) contribute to glioblastoma (GBM) progression by facilitating intercellular communication and releasing pro-tumorigenic molecules, including ATP and glutamate.

METHODS

The efficacy of abEC1.1, a monoclonal antibody that inhibits Cx26, Cx30, and Cx32 HCs, was assessed in vitro by measuring invasion capability, dye and Ca uptake, glutamate and ATP release in patient-derived GBM cultures or organoids. Adeno-associated virus (AAV)-mediated antibody gene delivery, or convection-enhanced delivery (CED) of the purified antibody, was used in vivo to test the effect on tumor growth and animal survival, using a syngeneic GBM mouse model. The ability of the antibody to affect glioma-related hyperexcitability was evaluated by patch-clamp recordings in a 2D co-culture model comprising astrocytes and neurons isolated from mouse hippocampi, seeded with GL261 cells.

RESULTS

abEC1.1 suppressed GBM cell invasion, reducing gliotransmitter release, and impairing tumor progression. In patient-derived GBM cultures, abEC1.1 significantly decreased cell migration and ATP/glutamate release. In vivo, AAV-mediated antibody gene delivery or CED of the purified antibody reduced tumor burden and prolonged survival in the GL261 syngeneic mouse model of GBM. Furthermore, abEC1.1 mitigated glioma-induced excitatory synaptic activity in the 2D co-culture model, suggesting a dual role in tumor control and hyperexcitability suppression.

CONCLUSIONS

Our findings establish Cx HC inhibition as a promising therapeutic avenue in GBM and highlight abEC1.1 as a potential candidate for clinical translation.