ABSTRACT
This chapter presents a brief review of cancer biology. It describes the multistep nature of carcinogenesis is demonstrated through initiation and promotion studies and through the cell culture studies of Barrett and co-workers on the development of cancer tumors of rat tracheal cells and Syrian hamster embryo fibroblasts. The chapter aims to illustrate how oncogenes and antioncogenes work at the molecular level. Some genetic changes such as gene amplification and chromosomal changes may also play a role in tumor promotion. Genetic changes are the dynamic part of the process of carcinogenesis. These genetic changes include deletion, gene mutation, reciprocal chromosomal translocation, gene amplification and other genic or chromosomal aberrations. Gene amplification is one of the genetic alterations which activates cellular oncogenes. Up to 1989, more than 57 viral and cellular oncogenes have been reported. The chapter also presents an overview of the key concepts discussed in this book.
