Onkologie. 2011:5(4):234-238

Primary cilia and their biological functions

Josef Dvořák¹, Veronika Sitorová², Dimitar Hadži Nikolov², Jaroslav Mokrý³, Igor Richter⁴, Stanislav Filip¹, Aleš Ryška², Jiří Petera¹

¹ Klinika onkologie a radioterapie LF UK a FN Hradec Králové

² Fingerlandův ústav patologie LF UK a FN Hradec Králové

³ Ústav histologie a embryologie LF UK Hradec Králové

⁴ Oddělení klinické onkologie, Krajská nemocnice Liberec, a.s.

The primary cilium is a sensory organelle protruding in the quiescent phase of the cell cycle from the surface of the majority of human

cells, including embryonic cells, stem cells and stromal cells of malignant tumors. The presence of primary cilium on the cell surface is

transient, limited to the quiescent G1 (G0) phase, as well as the beginning of the S phase of the cell cycle. Primary cilium is formed from

the centriole. Most cancer cells do not posses the primary cilium, with some exceptions, such as tumors depending on the Hedgehog

pathway -e.g. basal cell carcinoma or medulloblastoma. The primary cilium is present also in cells of triple negative breast carcinoma.

Primary cilia are equiped with a variety of receptors, including mechanosensors, receptors for growth factors (EGFR, PDGFR), hormones

(somatostatin), biologically active substances (serotonin) and morphogens (Hedgehog, Wnt). Multiple components of Hedgehog and Wnt

pathways are localized in the primary cilium. In the human cells possessing the primary cilium (majority of the human cells) Hedgehog

and Wnt pathways are located exclusively in primary cilium. The aim of this paper is review of the current knowledge of the biological

functions of the primary cilia.

Keywords: primary cilia, centrioles, cancer cells, EGFR, PDGFR, Hedgehog, Wnt

Published: December 1, 2011  Show citation