Molecular targets of primary cilia defects in cancer

Primary cilia are hair-like organelles that are present on the majority of mammalian cells. They are regarded as the regulatory 'hub' of cell functions due to their indispensable roles for several signaling pathways, such as Hh and Wnt pathways. Originally, cilia defects were found to cause a panoply of human diseases commonly referred to as 'ciliopathies'. Evidence is accumulating that cilia defects are involved in the onset and development of cancer. Some proteins that cause cilia defects have been identified as oncogenes in multiple cancer types. Hence, understanding the pathways that cause cilia defects in cancer is of utmost importance for the development of novel cancer therapeutic targets. The present review article provides a critical overview of the molecular targets of primary cilia defects in cancer, and highlights their vast potential as therapeutic targets and novel biomarkers.