Cell transformation: the role of oncogenes and growth factors.

An attempt is made to draw together diverse areas of biological research which have recently converged and opened up new experimental approaches to understanding the nature of cancer. In particular, the powerful techniques of molecular biology have been brought to bear on tissue culture systems. The case is made for the continued use of cell transformation in vitro as a real and useful model for cancer development. The hallmark of all cancer cells is loss of control over the cell cycle and the cellular elements involved, growth factors, growth factor receptors and signal transducers have been identified and in some instances shown to be encoded in cellular oncogenes. Moreover, as the molecular mechanisms underlying cell growth control are unravelled, those aspects involved in neoplastic change will be identified and this will lead to the development of definitive short-term tests for the detection of chemical carcinogens.