Primary cilia in gastrointestinal stromal tumors.

The primary cilium is a solitary, sensory, non-motile microtubule-based structure that arises from the centrosome and is projected from the surface of most human cells. The objective of the current pilot study was to conduct an investigation of presence and frequency of cilia in gastrointestinal stromal tumors (GIST).The presence of primary cilia in GIST was evaluated in 9 patients, including 8 primary tumors and 1 liver metastasis. In 2 patients the presence of primary cilia was evaluated not only in the primary tumor, but also in recurrence: in 1 patient in recurrence without previous treatment with imatinib and in 1 patient in recurrence after treatment with imatinib. The primary cilia of GIST cells were immunofluorescently stained with primary monoclonal anti-acetylated tubulin alpha antibody and cell nuclei with DAPI.We observed 9985 nuclei of cells of GISTs and 425 primary cilia in total. The median of frequency of primary cilia in cells of GISTs in all examined samples was 4.26%, in primary tumors was 4.32% and in metastases was 3.64%, respectively. This pilot study provides the evidence of the presence of primary cilia in GISTs in different organs. Primary cilia were identified in all examined cases of GIST, including primary tumors, metastases and recurrent lesions without and with previous treatment with imatinib.