engleski

Hh-Gli signaling affects cell cycle progression in ovarian dermoid primary cell lines.

Hedgehog-Gli signaling pathway is involved in embryonic development, and its malfunctioning is often associated with tumorigenesis and developmental malformations. The entire pathway is still not completely elucidated. It begins with binding of the ligand protein Sonic Hedhegog (Shh) to the transmembrane receptor Patched (Ptc). Ptc then releases its inhibition of Smoothened (Smo), and a cytoplasmatic cascade of phosphorylation and dephorsphorylation events leads to activation of transcription factor Gli and transcription of target genes, which include Cyclin D, Cyclin E, members of Wnt and TGF signaling pathways, and Ptc itself. Interest in Hedgehog-Gli pathway increased recently because of its evident involvement in fatal tumors, like lung, pancreatic and prostate cancers. Ovarian dermoid cysts (DC) or benign cystic teratomas are benign tumors descending from germinal cells. In approximately 80% of the cases, these lesions occur in young women (20 to 30 years of age) and represent 18% to 20% of benign ovarian tumors. They are also a characteristic feature of Gorlin syndrome patients. In most cases, dermoid cysts are unilateral, but they are bilateral in 10% to 15% of cases. Dermoid cysts can be composed of elements descending from all three of the germinal layers. We present an investigation of Hh-Gli signaling pathway in sporadic cases of ovarian dermoids not related to Gorlin syndrome. Previously, we have shown that methylation of Ptch promoter may contribute to pathway malfunctioning in these tumors. In this work we focus on primary cell cultures derived from human tumors. We developed primary cell cultures from ovarian dermoid tissue and several different clone lines were developed from the same tumor sample. Real-Time PCR demonstrated expression of the Hh-Gli pathway genes. This expression, although present in all clone lines, differs among them, confirming the heterogeneity of this tumor type. Immunofluorescent staining shows difference in localization of some of Hh-Gli pathway proteins among the clone lines, and some of them show reactivity to cyclopamine treatment, on both mRNA and protein level. We have also demonstrated effect of cyclopamine treatment on cell cycle progression of these clone lines by flow cytometry. Taken together, this data suggests Hh-Gli pathway involvement in tumorigenesis and cell cycle progression of ovarian dermoids. Since similar results were previously shown on ovarian carcinoma, we suggest Hh-Gli pathway aberration is an early event in transformation of ovarian cells in their progression towards malignancy.

Hh-Gli signaling; primary cultures; ovarian dermoid

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