Primary cilia found on HeLa and other cancer cells.

For many years now, researchers have known of a sensory appendage on the surface of most differentiated cell types called primary cilium. Primary cilia are both chemo- and mechano-sensory in function and have an obvious role in cell cycle control. Because of this, it has been thought that primary cilia are not found on rapidly proliferating cells, for example, cancer cells. Here we report using immunofluorescent staining for the ciliary protein Arl13b that primary cilia are frequently found on HeLa (human epithelial adenocarcinoma) and other cancer cell lines such as MG63 (human osteosarcoma) commonly used for cell culture studies and that the ciliated population is significantly higher (ave. 28.6% and 46.5%, respectively in starved and 15.7-18.6% in un-starved cells) than previously anticipated. Our finding impacts the current perception of primary cilia formed in highly proliferative cells.