Nuclear subdomains and cancer

Cancer develops when genetic changes, such as the activation of oncogenes and inactivation of tumour suppressors, allow a cell to escape the normal growth and proliferation restrictions. These functional changes ultimately result in structural alterations at both the nuclear and cellular levels. As such, cell morphology and biological marker expression are some of the main criteria in tumour pathology for diagnosis and prognosis. The development of advanced microscopy techniques has provided a much more detailed map of the nuclear landscape, and because of this, structural changes in subnuclear bodies induced during oncogenesis can be readily visualized. This type of analysis has identified novel cancer biomarkers in the form of nuclear structures associated with malignancy, such as the perinucleolar compartment (PNC). It has also allowed a much more detailed examination of nuclear body function, which has provided novel mechanisms and regulators of tumour suppression and oncogenesis. This chapter will focus on three of the most important subnuclear domains for cancer biology: promyelocytic leukemia nuclear bodies (PML NBs), the nucleolus, and the perinucleolar compartment (PNC).