Anti-Müllerian hormone inhibits growth of AMH type II receptor-positive human ovarian granulosa cell tumor cells by activating apoptosis

• Published in: Laboratory investigation 2011-11, Vol.91 (11), p.1605-1614
• Main Authors: Anttonen, Mikko, Färkkilä, Anniina, Tauriala, Hanna, Kauppinen, Marjut, MacLaughlin, David T, Unkila-Kallio, Leila, Bützow, Ralf, Heikinheimo, Markku
• Format: Article
• Language: English
• Subjects: 631/80/82/23; 631/80/86; 692/699/67/1059/602; 692/699/67/1517/1709; ALK; Analysis of Variance; Animals; Anti-Mullerian Hormone - pharmacology; Anti-Mullerian Hormone - therapeutic use; Apoptosis - drug effects; Biological and medical sciences; Biotechnology; Bromodeoxyuridine; cancer treatment; Cell Line, Tumor; DNA Primers - genetics; Female; Female genital diseases; Fundamental and applied biological sciences. Psychology; Granulosa Cell Tumor - drug therapy; Granulosa Cell Tumor - metabolism; Granulosa Cell Tumor - physiopathology; Gynecology. Andrology. Obstetrics; Humans; Immunohistochemistry; Investigative techniques, diagnostic techniques (general aspects); Laboratory Medicine; Medical sciences; Medicine; Medicine & Public Health; Mice; Müllerian inhibiting substance; ovarian cancer; Ovarian Neoplasms - drug therapy; Ovarian Neoplasms - metabolism; Ovarian Neoplasms - physiopathology; Pathology; Receptors, Peptide - metabolism; Receptors, Transforming Growth Factor beta - metabolism; research-article; sex cord stromal tumor; Signal Transduction - drug effects; Smad; Tetrazolium Salts; Thiazoles; Tumors
• ISSN: 0023-6837; 1530-0307
• DOI: 10.1038/labinvest.2011.116

Ovarian granulosa cell tumors (GCTs) are sex cord stromal tumors that constitute 3–5% of all ovarian cancers. GCTs usually present with an indolent course but there is a high risk of recurrence, which associates with increased mortality, and targeted treatments would be desirable. Anti-Müllerian hormone (AMH), a key factor regulating sexual differentiation of the reproductive organs, has been implicated as a growth inhibitor in ovarian cancer. GCTs and normal granulosa cells produce AMH, but its expression in large GCTs is usually downregulated. Further, as the lack of specific AMH-signaling pathway components leads to GCT development in mice, we hypothesized that AMH inhibits growth of GCTs. Utilizing a large panel of human GCT tissue samples, we found that AMH type I receptors (ALK2, ALK3 and ALK6) and type II receptor (AMHRII), as well as their downstream effectors Smad1/5, are expressed and active in GCTs. AMHRII expression was detected in the vast majority (96%) of GCTs and correlated with AMH mRNA and protein expression. AMH mRNA level was low in large GCTs, confirming previous findings on low-AMH protein expression in large human as well as mouse GCTs. To study the functional role of AMH in this peculiar ovarian cancer, we utilized a human GCT cell line (KGN) and 10 primary GCT cell cultures. We found that the AMH–Smad1/5-signaling pathway was active in these cells, and that exogenous AMH further activated Smad1/5 in KGN cells. Furthermore, AMH treatment reduced the number of KGN cells and primary GCT cells, with increasing amounts of AMH leading to augmented activation of caspase-3 and subsequent apoptosis. All in all, these data support the premise that AMH is a growth inhibitor of GCTs.