What's new in receptor mediated growth promotion of normal and malignant cells?

Growth control of normal cells is regulated by highly complex interactions of environmental signals and cell inherent conditions. Disorder of this system may result in the multi-step event of malignant transformation. This review discusses some aspects of the interaction of growth controlling agents, cell receptors, signal transmission, and cellular response. It focuses on the role of cell receptors that recognize and transduce information of cancer initiating and promoting agents to the cell: e.g. viruses, cancerogens, peptide and steroid hormones, growth factors, local growth promoting agents, and other environmental factors. All these growth modulators may be involved in triggering cell division. The mutual interactions of promotor induced signals, genes, and oncogenes are also discussed.