Lack of CSF-1 receptor message in Reed-Sternberg cells

The histogenesis of the Reed-Sternberg (R-S) cell in Hodgkin's disease is uncertain. Some have suggested that it is a derivative of the monocyte/macrophage lineage. To explore this possibility, we have searched for the presence of mRNA corresponding to the c-fms proto-oncogene, a marker for cells of the monocyte/macrophage lineage which encodes the colony-stimulating factor-1 receptor. In situ hybridization was performed using a single-stranded c-fms complementary RNA (cRNA) to probe R-S cells, lymphocytes, and eosinophils from touch imprints of a lymph node from a 12-year-old boy with mixed cellularity Hodgkin's disease in relapse. The probe was synthesized from a bacterial plasmid, pSM3, into which a portion of v-fms (a viral-derived oncogene) had been inserted. The plasmid was linearized with a restriction endonuclease, and 35S-labeled cRNA was synthesized from the DNA template using T3 RNA polymerase and the nucleotide analog [35S]UTP. Positive control hybridizations were obtained with the human acute promyelocytic cell line HL-60 induced to monocyte differentiation. R-S cells were clearly negative, supporting a cell of origin other than the monocyte. In situ hybridization is a potentially powerful method for exploring differentiation and assigning cell lineage in R-S cells.