Granulosa cell tumor with activated mTOR-HIF-1alpha-VEGF pathway

• Published in: The journal of obstetrics and gynaecology research 2010-04, Vol.36 (2), p.448-453
• Main Authors: Miyazawa, Masaki, Yasuda, Masanori, Fujita, Mariko, Hirabayashi, Kenichi, Hirasawa, Takeshi, Kajiwara, Hiroshi, Muramatsu, Toshinari, Miyazaki, Sayuri, Harasawa, Makiko, Matsui, Naruaki, Ogane, Naoki, Murakami, Masaru, Mikami, Mikio, Yanase, Toshihiko, Osamura, R Yoshiyuki
• Format: Article
• Language: English
• Subjects: Adult; Aged; Blotting, Western; Cell Line, Tumor; Female; Granulosa Cell Tumor - metabolism; Granulosa Cell Tumor - surgery; Humans; Hypoxia-Inducible Factor 1, alpha Subunit - metabolism; Immunohistochemistry; Intracellular Signaling Peptides and Proteins - metabolism; Middle Aged; Ovarian Neoplasms - metabolism; Ovarian Neoplasms - surgery; Protein-Serine-Threonine Kinases - metabolism; Signal Transduction - physiology; TOR Serine-Threonine Kinases; Vascular Endothelial Growth Factor A - metabolism
• ISSN: 1447-0756
• DOI: 10.1111/j.1447-0756.2009.01127.x

The DNA-binding activity of hypoxia-inducible factor-1 alpha (HIF-1alpha) has been analyzed for various gynecological tumors. Among the tumors that were studied, there was a finding of a high level of DNA-binding HIF-1alpha activity, although it was limited to one case of adult type granulosa cell tumor (GCT). In this case a 60-year-old female had marked immunohistochemical expression of HIF-1alpha. The expressions of the mammalian target of rapamycin (mTOR) and phosphorylated-mTOR (p-mTOR) were also marked, and vascular endothelial growth factor (VEGF) was moderately expressed. To compare the expression profiles, 11 consecutive cases with adult type GCT were used. All cases showed marked expressions of HIF-1alpha and mTOR, but p-mTOR expression was moderately to markedly observed in four of the 12 cases. VEGF was expressed in all cases in varying degrees. Based on the evidence that downregulation of the mTOR pathway due to treatment with rapamycin (everolimus) would suppress tumor cell growth, an experimental study using the GCT cell line was designed to clarify whether HIF-1alpha and VEGF expressions decline. As a result, the expressions of p-mTOR, HIF-1alpha and VEGF were suppressed, but those of mTOR were not. It was concluded that mTOR-targeted therapy may represent a promising strategy for some GCT with an activated mTOR-HIF-1alpha-VEGF pathway.