Detection of proliferating S-phase brain tumor cells by in situ DNA replication

Object. Current methods used to describe the proliferative status of brain tumors rely on labor-intensive, potentially costly procedures. This article provides a description of a rapid, inexpensive, uncomplicated technique us ed to identify proliferating cells in tissue obtained at the time of resect ion. Methods. Touch preparations of 16 fresh astrocytic tumors and four fresh he althy temporal neocortical tissue samples were obtained at the time of surg ery. Slides were placed in hypotonic potassium chloride to permeabilize the ir membranes, incubated in nucleotide precursors, and labeled with bromodeo xyuridine; they were later examined with the aid of a fluorescence microsco pe. The percentage of tumor cells in the S phase increased in conjunction w ith the grade of tumor and corresponded with the findings of immunohistoche mical staining for the cell-cycle marker MIB-1. These results were confirme d in cell culture by using normal human astrocytes and two glioma cell line s. Slides can be analyzed in as little as 30 minutes after removal of tissu e during surgery. Conclusions. In this study the authors describe a simple method by which ce lls in the S phase of the cell cycle, which are contained in fresh tumor ob tained at the time of surgery, can be labeled. This method may prove a usef ul adjunct to frozen-section analysis and may permit discrimination of neop lastic tissues from other tissues observed in small specimen samples.