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

Abstract

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-Mü llerian 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 AMHsignaling 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.

Effect of Anti-Müllerian hormone (AMH) and bone morphogenetic protein 15 (BMP-15) on steroidogenesis in primary-cultured human luteinizing granulosa cells through Smad5 signalling

“…Indeed, both AMH and BMP-15 demonstrated a 3-fold augmentation of, indicating a downstream activation of the serine/threonine receptor pathway. This evidence comes in agreement with previously published data from rodents [7,11,12] and the tumor-derived human granulosa cell line KGN [54], where it has been shown that AMH activates Smad5 phosphorylation by binding to the AMHRII/-ALK2/3/6 complex, as well as, with studies in COV434 ovarian granulosa tumor cells were it has been demonstrated that BMP-15 facilitates its own effect through binding to the BMPRIB/ALK3 receptor complex and subsequently activating the Smad1/5/8 phosphorylation [55]. The fact that Smad5 is a common target for both AMH and BMP-15 in our system can explain why combined administration of these factors did not lead to an additive effect on steroids production.…”

The clinical utility of serum anti‐Müllerian hormone in the follow‐up of ovarian adult‐type granulosa cell tumors—A comparative study with inhibin B

“…The previous notion that serum AMH is increased in patients with large AGCTs was confirmed in our study. Interestingly, tissue AMH expression is decreased in larger AGCTs, leading to a discrepancy with serum AMH levels. This may simply reflect the size of the tumor; larger AGCTs release more AMH into the circulation, while overall tissue expression remains low.…”

Evidence of Spontaneous Recovery of Granulosa‐Theca Cell Tumour in a Heifer: A Retrospective Report

“…The fact that in vitro treatment of a human ovarian granulosa cell tumour (GCT) cell line with AMH results in inhibition of GCT through activation of the apoptosis pathway (Anttonen et al. ) could explain the self‐curing of the RO in the current report. In support of this, the histopathological examination of the current case revealed that the extracted RO contained degenerated granulosa cells in the wall of the cyst.…”