TUMOR GENES AND THEIR PROTEINS IN CYTOLOGIC AND SURGICAL SPECIMENS - RELEVANCE AND DETECTION SYSTEMS

Oncogenesis is the consequence of a series of genetic alterations that allow unrestrained cellular growth, tissue invasion, and eventual met astases. Tumor-related genes can be classified into functional categor ies. Proto-oncogenes/oncogenes have a stimulatory role in cell growth, and the inactivation of cancer-suppressor genes/antioncogenes results in the loss of cell cycle regulation. More recently, three other grou ps of tumor-related genes have been recognized. They include the antia poptosis genes which protect from programmed cell death, the antimetas tasis genes, and multidrug resistance genes. Besides aiding in tumor d iagnosis, the detection of such tumor-associated genes and their produ cts allows the identification of individuals with an inherited predisp osition to neoplastic growths, and the overexpression of many of these oncogene products has been shown to be a potential marker of tumor be havior and a predictor of treatment outcome and response. The ability to utilize DNA and RNA probes for nucleic acid hybridization and polym erase chain reaction procedures in cell and tissue preparations of sol id tumors and lymphoid proliferations expands and complements the info rmation provided by immunohistochemical techniques. These probes allow direct visualization and correlation of specific genes and their prot ein products with cytomorphologic features, and form a powerful additi on to the armamentarium of the cytopathologist and surgical pathologis t. (C) 1995 Wiley-Liss, Inc.