Antitumor Effects of Monoclonal Antibodies to Connexin 43 Extracellular Fragment in Induced Low-Differentiated Glioma

We studied the effect of intravenous administration of monoclonal antibodies to the second extracellular loop of connexin 43 (MAbE2Cx43) on the dynamics of glioma growth and survival of experimental animals. Morphometric analysis of magnetic resonance imaging data showed that weekly intravenous administration of MAbE2Cx43 in a dose of 5 mg/kg significantly reduced glioma volume starting from day 21 after tumor implantation. By day 29, the mean volume of glioma in the experimental group (therapy with specific antibodies) was 2-fold lower than in controls. Deceleration of glioma growth in rats receiving MAbE2Cx43 was accompanied by a significant prolongation of rat lifespan (according to Kaplan-Meier test) and even led to complete recovery without delayed relapses in 19.23% animals. The mechanism of tumor-suppressing effects of antibodies can be related to inhibition of specific functions of connexin 43 in glioma cells in the peritumoral zone.