Cell surface membrane antigen present on neuroblastoma cells but not fetal neuroblasts recognized by a monoclonal antibody (KP-NAC8). 
Neuroblastoma (NB) arises from primitive sympathetic neuroblasts in the adrenal gland or the sympathetic ganglion.  NB in situ, sometimes observed in the adrenal glands of autopsied infants, is considered to be a premalignant lesion that may develop into NB.  Little is understood about the morphological and biochemical changes that accompany this malignant progression.  In this study, a unique monoclonal antibody, KP-NAC8, raised against a human NB cell line is described.  This binds to NB cells but not to fetal neuroblasts.  The antibody recognizes a Mr 200,000 surface protein on NB cells.  KP-NAC8 binds to 15 of 17 human NB cell lines and all 26 fresh NB samples either from tumor tissues or from marrow aspirates involved with tumor.  The antibody was found to cross-react with some other tumor cell lines, namely, Ewing's sarcoma (1 of 2), melanoma (1 of 4), lung cancer (3 of 3), and leukemia (2 of 14) cell lines.  However, KP-NAC8 did not bind to any rhabdomyosarcoma (0 of 4), Wilms' tumor (0 of 4), retinoblastoma (0 of 2), glioma (0 of 4), and gastric cancer (0 of 2) cell lines examined.  Among fetal tissues, KP-NAC8 did not react with normal neuroblasts in the adrenal glands of 5 fetuses.  In a further study, the membrane phenotype of fetal adrenal neuroblasts was analyzed by a panel of 12 monoclonal antibodies including KP-NAC8.  A comparison of the binding of the same panel of antibodies to fresh NB revealed that antibodies UJ13A, UJ127:11, PI153/3, anti-Thy-1, A2B5, BA-1, BA-2, HSAN1.2, and Leu-7 bound to both fetal adrenal neuroblasts and NB cells.  Monoclonal antibodies OKIa-1 and J5 did not bind to either tissues.  The only antibody that could distinguish fetal adrenal neuroblasts from NB cells was KP-NAC8.  KP-NAC8 may, therefore, define a differentiation-related antigen that may prove helpful in understanding the biological nature of NB and NB in situ.