High resolution

Module 12: Figure the cancer signalsome

Summary of the major genotypic remodelling processes that result in cancer.

There are two major aspect of the remodelling process. The proliferative signalling pathways are switched on, while the apoptotic pathway is switched off. Oncogenes are derived from the normal stimulatory elements of proliferative signalling pathways (proto-oncogenes) that become constitutively active. In effect, these components of the signalsome become hypersensitive to increase cell proliferation. In addition, tumour suppressor genes that normally function to inhibit proliferation are switched off. The apoptotic signalsome is remodelled so that it becomes hyposensitive by switching off the p53 surveillance system. In addition, the cells also escape from the immune surveillance system that normally kills cancer cells. The increase in cell proliferation and the decrease in apoptosis are the hallmarks of cancer cells.