Inhibition of subcutaneous growth of Ehrlich ascites carcinoma (EAC) tumor by post-immunization with EAC-cell gangliosides and its anti-idiotype antibody in relation to tumor angiogenesis, apoptosis, cell cycle and infiltration of CD4+, CD8+ lymphocytes, NK cells, suppressor cells and APC-cells in tumor.

Both EAC-tumor associated gangliosides and its anti-idiotype antibody inhibited growth of this tumor significantly. Immuno-histological studies with von Willebrand Factor (vWF) antibody indicated that tumor angiogenesis as determined by expression of vWF decreased in tumors of mice, post-immunized with EAC-cell gangliosides as well as its anti-idiotype antibody. Infiltration of various immune cells of the host in the tumor correlated to some extent with tumor-growth inhibition. Apoptosis study using AnnexinV-FITC and propidium iodide indicated that tumor growth inhibition in mice post-immunized with EAC-gangliosides and its anti-idiotype antibody were due to enhanced apoptosis and cell death. Cell cycle analysis by FACS indicated that EAC-cell associated gangliosides and its anti-idiotype antibody were acting both at the M2 i.e. S and M3 i.e. G2/M phases of the cell cycle to arrest tumor growth.