The Cytolysis of Human Neuroblastoma Cells by a Natural IgM ‘Antibody’-Complement System in Pregnancy Serum

Abstract

Cell lines from 26 human cancers were studied for cytotoxicity when treated with normal pregnancy serum. Cytotoxicity, manifested by cell death and cytolysis, occurred in 4 of 8 neuroblastomas studied: SK-N-SH, NGP, LAN-5, and IMR-32. In NGP and SK-N-SH, evidence is presented showing that the cytotoxicity resulted from the cell-surjace binding of a natural IgM ‘antibody,’ which sensitized the neuroblastoma cells to the lytic action of complement (C). This system may be involved in a cytolytic form of spontaneous regression of neuroblastoma.