Primary cilia emerge as key players in cancer
Microscopic command centres in our bodies called primary cilia—once thought irrelevant—could be hidden switches powering cancer growth and drug resistance, new research reveals.
The review, published in Oncogene, analyses how cilia, tiny hair-like structures on cells, may play a role in cancer. These structures help cells detect signals from their surroundings. While some cancers appear to destroy them, others seem to rely on cilia to grow.
“We’re only just beginning to understand how powerful these structures are in cancer,” said Dr Barbara Tanos at Brunel University of London. “They work like a Rubik’s cube. If each side of the cube contains instructions for the cell to perform one function, rotating one layer of the cube changes the instructions from every side.”
In healthy cells, primary cilia are essential for growth and repair. They act like little aerials, monitoring the environment—detecting things like fluid flow or chemical changes.
But cancer seems to hijack molecules in cilia. Instead of helping the body, they start helping the tumour—activating key survival pathways that let cancer cells multiply uncontrollably, invade new tissues and resist chemotherapy. These molecules can be inhibited with medicines that are already being used in the clinic for other diseases, Dr Tanos explains.
“Once we identify new mechanisms of how cilia control cancer growth, this can help uncover drug targets within ciliary signalling pathways. If the medicines are already available, this can be quite soon. Cilia itself can also be the target, and there are drugs that inhibit proteins that mediate the formation of cilia.”
While cilia were once thought to be irrelevant to cancer, they can play a central role in helping tumours adapt and resist drugs. Particularly when cancers become harder to treat.
“The role of cilia in cancer is, in itself, unexpected,” Dr Tanos said. “When we started studying this structure, we expected cancer cells not to have cilia, because the presence of cilia had been associated with cell stasis. So, while some cancers don’t have cilia, cilia can become necessary for others, particularly when tumours become drug-resistant.”
Previously, the Tanos Lab investigated how cilia affect drug resistance. They found that cancer cells that stopped responding to kinase inhibitors—major cancer drugs that block signals telling cells to grow—had longer and more cilia than cells that still responded.
Understanding how cilia regulate cancer could be a turning point for how scientists treat hard-to-kill tumours. Targeting cilia—either by disrupting their formation or silencing their signals—might make existing drugs work better or bring failed treatments back into play.