Loss of cell polarity and cancer are tightly correlated, but proof for a causative relationship has remained elusive.
In stem cells, loss of polarity and impairment of asymmetric cell division could alter cell fates and thereby render daughter cells unable to respond to the mechanisms that control proliferation.
Tumorigenesis
Loss of function of any of several genes that control the fate of a stem cell’s daughters may result in hyperproliferation, triggering a chain of events that subverts cell homeostasis in a general sense and leads to cancer.
Recent genetic studies in flies have added further support to an increasing body of evidence that suggests that stem cells might be the cell-of-origin of certain tumours.
Malfunction of the mechanisms that control the division of stem cells and the developmental fate of the two resulting daughters could be one of the initial events that steers cells into malignant transformation. These studies suggest a role for controlled spindle orientation in suppressing stem-cell overgrowth.
In parallel, the machinery that drives asymmetry in stem cells has been further characterized, identifying new components and uncovering the unique, highly sophisticated behaviour of centrosomes in these cells.
References
Gonzalez C. Spindle orientation, asymmetric division and tumour suppression in Drosophila stem cells. Nat Rev Genet. 2007 Jun;8(6):462-72. PMID: 17510666
Caussinus E, Gonzalez C. Induction of tumor growth by altered stem-cell asymmetric division in Drosophila melanogaster. Nat Genet. 2005 Oct;37(10):1125-9. PMID: 16142234
