Fibroblast Growth Factor Receptor 2 Expression May Be Involved In Transformation of Ovarian Endometrioma to Clear Cell Carcinoma of the Ovary

Abstract

Objective: The objective of this study was to determine the genes that may be associated with malignant transformation of ovarian endometrioma.

Methods: Endometriotic epithelial cells were isolated from tissues derived from chocolate cyst linings by laser capture microdissection. A Gene Chip Human Genome U133 Plus 2.0 Array was applied to evaluate levels of gene expression in 3 different groups of epithelial cells: epithelial cells of endometrioma, epithelial cells of endometrioma adjacent to clear cell carcinoma, and epithelial cells of clear cell carcinoma. As a validation assay, real-time reverse transcriptase–polymerase chain reaction and immunohistochemical analyses were performed.

Results: Gene expression analysis identified differential expressions among the 3 groups of epithelial cells. Using the classification of a signaling pathways database, 9 genes (12 gene probes) were selected from among 39 up-regulated genes indicating more than 2-fold higher expression between any comparisons of the 3 groups in the comprehensive microarray. Enhancement of fibroblast growth factor receptor 2 (FGFR2) gene expression was detected by microarray using 3 distinct probes. Gene and protein expression of FGFR2 differed significantly between epithelial cells of endometrioma and the epithelial component of clear cell carcinoma.

Conclusions: We demonstrated that FGFR2 may play a significant role in the carcinogenesis of endometriosis and thus represents a potential therapeutic target.