Analysis of the Scrib, Dlg and Lgl tumour suppressors in cell cycle regulation using the Drosophila animal model system

点击翻译按钮获取中文摘要

Cancer is a disease that is likely to affect 1-3 people at some point in their lifetime. Therefore, understanding what causes cancer is of major importance to medical science. Cancers arise through the accumulation of mutations that alter normal cell proliferation control, differentiation, cell death or cell movement. Many genes involved in cancer have been identified, however, there are likely to be many more genes, that when disrupted or misexpressed can lead to cancer. We are interested in the regulation of cell proliferation, and have been studying this in the genetically amenable animal model system, the vinegar fly, Drosophila. A key regulator of cell proliferation in all multicellular organisms is Cyclin E, which is required to drive cells from the G1 (resting state) into S phase (where DNA replication occurs). Correct control of Cyclin E is important in limiting cell proliferation and many cancer-causing mutations result in up-regulation of this critical cell cycle regulator. We have used a genetic approach to identify novel negative regulators of Cyclin E. This proposal focuses on a group of these regulators, the Drosophila tumour suppressors, Scrib, Dlg and Lgl, which act in a common genetic pathway to link cell polarity (cell shape) to cell proliferation. In mutants of these genes, cyclin E is up-regulated and inappropriate cell proliferation occurs. The aims of this proposal are to determine the signalling pathway and the transcription factors that act to upregulate cyclin E in scrib-dlg-lgl mutants. We will use the powerful genetics of Drosophila to examine candidate genes and to screen for novel genes involved in the upregulation of cyclin E in scrib-dlg-lgl mutants. The expected outcome of this project is to elucidate how Scrib-Dlg-Lgl act to control cell proliferation. scrib, dlg and lgl are present in mammals, therefore, this study is directly relevant to the control of cell proliferation and the development of cancer in humans.