Localization of neuroblastoma in vivo with tumor-specific antibodies

Studies of the mouse C-1300 neuroblastoma were undertaken in order to isolate tumor-specific antibodies and harness them for detection of tumors in vivo. Preliminary investigations demonstrated the strain-growth specificity of the neuroblastoma in A/Jax male mice and established the requirement for tumor viability for successful adoptive passage. Intradermally passaged tumor permitted extended survival of mice so that serum could be sampled at intervals for the presence of tumor-specific antibodies. By means of an indirect radioimmunoassay with glutaraldehyde-fixed identified in the serum of tumor-bearing hosts 6 days after inoculation, with a steady increase in antibody levels observed through Day 22. An eluate in which immunoglobulin G antibodies were identified by immunoelectrophoresis was obtained from purified tumor cells by acid buffer incubation. These antibodies were labeled with 125-I, absorbed with normal tissues, and injected into tumor-bearing mice. A selectively collimated single-probe isotope localization was positioned over the intradermal tumor, while the rest of the animal was shielded with lead. With this device, 125-neuroblastoma eluate was significantly taken up in the neuroblastoma but not in the mouse head or in a reticulum cell sarcoma control. Increasing uptake of MOPC 141 125-I-immunoglobulin G was not observed in either tumor. These studies suggest that the mouse neuroblastoma may provide a source of tumor-specific, antibodies and that, with sensitive monitoring devices, these antibodies may be utilized to localize occult neoplastic tissue in vivo.