P-563: The genes and pathways involved in pathogenesis of leiomyoma and altered by gonadotropin releasing hormone analogue

Abstract

Leiomyoma is one of the most common gynecological diseases, with abonormal highly proliferative smooth muscle cells and fibroblasts, and has been linked to infertility. Several microarray-based studies have been applied in leiomyoma and several factors were suggested to play some roles in leiomyoma pathogenesis during the past few years. However, the pathological mechanism of myoma is still unclear. In this study, using cDNA microarray with pathway analysis, several novel genes and furthermore, the pathways which are highly activated in myoma and altered after gonadotropin releasing hormone analogue (GnRHa) therapy have been identified. Prospective study. This study was approved by the Institutional Review Board Committee of our hospital. Leiomyoma tissue samples (n>8) for cDNA microarray, real time quantitative RT-PCR (Q-PCR), and immunohistochemistry (IHC) were obtained from women who were undergoing surgery. In this study, the human 9,600 cDNA microarray was used to analyze the differentially expressed genes in leiomyoma with or without 2 months of GnRHa treatment before the surgery. The possible pathological mechanisms of leiomyoma were predicted by KEGG® and Biocarta® pathway analysis on our public website (http://140.120.213.10:8080/crsd2/SpecificDB.jsp). Q-PCR analysis and IHC staining were used to confirm the differentially expressed genes and their protein expression levels in the tissues. According to cDNA microarray analysis, there are 172 genes were up-regulated (>3 times) in myoma without GnRHa treatment, whereas 29 genes were highly up-regulated (>5 times), when compared with the gene expression levels in myoma treated with GnRHa. Meanwhile, there are 70 genes were down-regulated (>3 times) in myoma without GnRHa treatment, whereas 17 genes were dramatically down-regulated (>5 times), when compared with the gene expression levels in leiomyoma treated with GnRHa. The pathway analysis revealed that the cell growth (cell cycle) modulators (cyclin G1, G2, k-ras, rab-2, PCNA, and cartilage-derived maphogenestic protein-1), angiogenic pathway (vascular endothelial growth factor, epithelial growth factor receptor, fibroblast growth factor, epithelial growth factor receptor substrate 6, angiopoietin-2, stromal cell derived factor-1, and caldesmon-1), and cell adhesion machinery (vinculin, gamma-actin, and laminin-entactin/nidogen) were highly expressed in leiomyoma and significantly down-regulated following GnRHa treatment. According to the results, these growth-related factors, angiogenic factors, and extracellular matrix could be involved in the pathogenesis of leiomyoma and possibly in the regression of myoma following GnRHa treatment. To identify the novel genes and pathways are altered after GnRHa therapy in leiomyoma might improve our understanding in the pathological mechanisms of leiomyoma and might be helpful to find the specific markers for diagnosis and prognosis, and further develop certain novel new drug to targeting or therapeutic intervention for leiomyoma.