Revealing cancer initiating cells in metastatic melanomas by harnessing the host′s anti tumor humoral immune mechanisms

Abstract

Results Cell cultures grew out of the great majority of the starter metastatic tissue specimen and cancer initiating cells could be sorted (BD FACSAvia Sorter) by colocalized unique sialilated glycosphingolipids and anti CD20 binding capacity. Characteristic growth pattern, spheroid forming, CSC markers like CD133, Nestin, ABCB5, CD20 and unique GD3 gangliosides were found. Patients′ sera and selected patients′ Epstein Barr Virus transformed cell supernatants in bulk or after limiting dilution cloning were tested for cancer binding by ELISA and immunofluorescence. Our novel tumor infiltrating B cell antibody phage display technique and DNA sequence cluster analysis (Vector NTI Advance 11, Bioedit 7.0, ClustalX2.0.11) resulted in some antibody fragments, belonging to representative tumor binding antibody variable region subgroups, with defined silalilated glycosphingolipid specificity.