The Effect of Primary Cilia Restoration on Cancer Cells

Primary cilia are sensory organelles that exist on the surface of most cells. Since primary cilia play an important role in cell cycle and cilia‐related signaling pathways (e.g. Hedghog and Wnt signaling pathways), cilia have been proposed to be involved in cancer development. In our current study, we characterized the expression of the primary cilia in two prostate cancer (PC3 and DU145), and one lung cancer (NL20‐TA) cell lines by examining cilia formation and measuring cilia length. Moreover, we investigated the correlation between primary cilia and cilia‐related signaling pathways. We found that the frequency and the length of the primary cilia were reduced in PC3 prostate cancer. Primary cilia were absent in DU‐145 prostate cancer and NL20‐TA lung cancer. Furthermore, the β‐catenin of Wnt signaling pathway was elevated in the prostate and lung cancers, suggesting an association between primary cilia and Wnt signaling in cancer cells. We also assessed the ability of rapamycin to restore primary cilium expression in cancer cells. We found that treatment with rapamycin for 8 days increased the percentage of ciliated cells in PC3 prostate cancer and restored primary cilium formation in DU145 prostate cancer and NL20‐TA lung cancer. We next investigated the correlation between primary cilia and Wnt signaling pathways after restoring primary cilia expression in cancer cells. We found that treatment with rapamycin for 8 days reduced the level of β‐catenin in prostate cancer cells. In summary, our data show a potential role of primary cilia in cell proliferation. Support or Funding Information SACM