Fingerprinting of DNA and RNA by arbitrarily primed polymerase chain reaction: applications in cancer research.

RNA fingerprinting by RAP-PCR is a powerful tool for the temporal and spatial analysis of differential gene expression. Many biological situations exist where differential gene expression results in distinguishable phenotypes, including, for example, tissue and cell types, responses to hormones, growth factors, stress, and the heterologous expression of certain genes. There are several methods for detecting differential gene expression and cloning differentially expressed genes that do not rely on a biological assay of phenotype. Most of these methods fall into two general categories: subtractive hybridization and differential screening. RAP-PCR offers numerous advantages over these methods, including its simplicity and its ability to compare the fluctuations in gene expression between multiple samples simultaneously using minute amounts of RNA. In addition, RAP-PCR can yield information on the overall patterns of gene expression between different cell types or between different physiological conditions of the same cell type. Comparison of the RAP-PCR fingerprints from these different experimental groups permits one to draw inferences regarding the overall cellular states of gene expression and the interrelation between gene transcripts belonging to the same or different regulatory pathways. Hypotheses regarding signal transduction pathways can be obtained using this information. RAP-PCR offers applications in cancer research in the detection of tumor-specific alterations in gene expression, providing a bountiful source of tumor markers. The pleiotropic impact of oncogene activation, tumor suppressor gene inactivation, and mutator mutations, in gene regulation, can be readily assessed by RAP-PCR in model systems both in vitro and in vivo.