Cancer cell structure: actin changes in tumour cells--possible mechanisms for malignant tumour formation

Improvement in treatment of solid tumours is likely to depend on a better knowledge of the biological mechanisms of malignant tumour formation. Over the past few years a great deal of progress has occurred in our understanding of cell biology, and one of the main areas of development has been the cell cytoskeleton. The cytoskeleton contributes to maintenance of cell structure and to a variety of other cell functions. Several studies have implicated one of the elements of the cytoskeleton, the microfilaments, in malignant change, and these microfilaments are directly affected by the activity of some 'oncogenes'. Changes in the control of filament polymerization and organization have been demonstrated in response to the activity of the src oncogene. The protease trypsin has been shown to affect the actin cytoskeleton grossly and illustrates that proteases released in the vicinity of tumours may have a biologically significant effect on the internal structure and stability of the cell. Further investigation of the microfilament system may reveal important clues for future manipulation of the cancer cell and the treatment of the patient with advanced cancer.