For immunofluorescence analysis, SKOV3 cells were cultured on cover slips and t

Quite a few gangliosides including GD2, GM2, GD3, NGcGM3 and OAcGD2 are expressed at very high levels on the plasma membrane of several tumor cells of neuroectodermal ori gin, as well as on the cells of small cell lung cancers and lymphomas. As a potential INK 128 ic50 target molecule for anti tumor therapy, ganglioside GD2 has certain advantages when compared to other tumor associated gangliosides since this glyco lipid is highly expressed in tumor cells and it is not expressed at all, or expressed at a very low level in normal cells. Specifically, in normal non malignant tissues, GD2 expression is mostly restricted to neurons, skin melano cytes and peripheral nerves.

Moreover, on the surface of normal cells, GD2 is a minor ganglioside, comprising 1 2% of total amount of gangliosides, and its level of expression is 3 8 fold lower in comparison with other tumor associated gangliosides such as GD3, In tu mors the highest level of GD2 expression is observed on the cell surface of almost all types of the primary neuroblastomas KU-57788 ic50 reaching 107 molecules per cell, In addition, GD2 is detected in about 75% of primary and metastatic melanomas, GD2 is also expressed in variety of other tumors including bone and soft tissue sarcomas, small cell lung cancer, and brain tumors, Today, one of the most promising approaches for cancer immunotherapy is the treatment of cancer patients with monoclonal antibodies directed against tumor associated molecules including ganglioside GD2.

Several monoclonal buy Lonafarnib antibodies specific for the GD2 were recently used in clinical trials, The anti GD2 mAbs appear to act mainly through binding to the cell surface of tumor cells and activation of complement system that leads to complement dependent lysis and or antibody mediated cellular cytotoxicity that involve immune cells as effectors, At the same time, several studies suggested that anti GD2 mAbs may cause direct induction of cell death in a number of tumor cell lines, However it has not been thoroughly investigated. The functional role of GD2 ganglioside in this process has not been demon strated, and possibility of cross reactivity of anti GD2 mAbs with other gangliosides and glycosylated proteins was not yet tested. In this study we demonstrated a new role of ganglio side GD2 as a receptor for induction of non classical cell death of GD2 positive tumor cells of various origins.

We found that anti GD2 antibodies specifically interacted with GD2 resulting in direct induction of mitochondria dependent cell death. We also found that the level of GD2 expression directly correlated with susceptibility of these cells to cytotoxicity induced by anti GD2 anti bodies. Thus, our study establishes a new role of GD2 as a functionally active biomarker for anti cancer therapy. Methods Cell lines and hybridomas EL 4, L1210, Jurkat cell lines were cultured in RPMI 1640, IMR 32 and Neuro 2A cell lines were cultured in EMEM medium, human melanomas mS and A375 were cultured in DMEM medium. All culture mediums were supplemented with 10% heat inactivated fetal bovine serum, 2 mM L glutamine and antibiotic antimycotic solution, Hybridoma cells HB9326 were maintained in Hybri Max RPMI 1640 medium, supplemented with 10% FBS, 2 mM L glutamine and anti biotic antimycotic solution.