Flow cytometric detection of p53 protein expression in archival (frozen) pediatric neural tumors

Purpose: This study defines how frozen, non-fixed pediatric neural tumors can be utilized to rapidly quantify p53 status (mere presence is indicative of abnormal nonfunctioning p53) using immunochemically labeled detection and flow cytometry (FCM). Patients identified as having detectable p53 profiles become targets for eventual gene delivery therapy. Methods: Nine pediatric tumors of varied pathology were identified from previously snap-frozen material. These tissues were mechanically disaggregated, immunochemically labeled in a three step fluorescent (FITC) technique with monoclonal antibodies specific for human p53 protein and analyzed by flow cytometry for the absence or presence of p53 protein. Results: In our mixed pediatric neural tumors, three of nine stained positive for p53 or 33% of the samples would be potential candidates for gene therapy. Conclusions: These results are consistent with previously reported data from fixed sections of immunostained samples. However our use of frozen tumors and biopsy sized samples offers a more rapid, convenient and reliable determination of p53 protein status. The procedural improvement of accuracy is attributable 10 FCM, which eliminates the subjective variability inherent in the more conventional histologic and cytologic techniques. As such, this procedure allows for quick, precise and controlled p53 analysis on frozen biopsy-sized samples.

Duke Scholars

Author Oren N Gottfried Neurosurgery