c-Jun N-terminal Kinase Inhibitor II (SP600125) Activates Müllerian Inhibiting Substance Type II Receptor-Mediated Signal Transduction

Abstract

Müllerian inhibiting substance (MIS), the hormone required for Müllerian duct regression in fetal males, is also expressed in both adult males and females, but its physiological role in these settings is not clear. The expression of the MIS type II receptor (MISRII) in ovarian cancer cells and the ability of MIS to inhibit proliferation of these cells suggest that MIS might be a promising therapeutic for recurrent ovarian cancer. Using an MISRII-dependent activity assay in a small-molecule screen for MIS-mimetic compounds, we have identified the c-Jun N-terminal kinase inhibitor SP600125 as an activator of the MIS signal transduction pathway. SP600125 increased the activity of a bone morphogenetic protein-responsive reporter gene in a dose-dependent manner and exerted a synergistic effect when used in combination with MIS. This effect was specific for the MISRII and was not seen with other receptors of the TGFbeta family. Moreover, treatment of mouse ovarian cancer cells with a combination of SP600125 and paclitaxel, an established chemotherapeutic agent used in the treatment of ovarian cancer, or with MIS enabled inhibition of cell proliferation at a lower dose than with each treatment alone. These results offer a strong rationale for testing the therapeutic potential of SP600125, alone or in combination with already established drugs, in the treatment of recurrent ovarian cancer with a much-needed decrease in the toxic side effects of currently employed therapeutic agents.

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

“…Activation of apoptosis and/or inhibition of cell cycle by AMH in ovarian carcinomas may enhance the effectiveness of chemotherapeutics, 27,59 and lead to less toxicity and increased tolerance to chemotherapy. Further studies utilizing mouse models for human GCT are, however, needed to ultimately address the implications of AMH as a supplementary treatment modality for GCTs.…”

“…The production of purified, fully cleaved AMH has been achieved only recently, 51 and with this AMH one would need only 1:1000 of the dose compared with partially cleaved AMH. Targeting AMHRII with activating antibodies 62 or small molecule agonists 23,59 presents another attractive option for supplementary treatment of AMHRII-positive advanced or recurrent GCTs. Nevertheless, the observed activation of apoptosis in GCTs may not necessarily involve AMHRII, given that the doses used in this study are more robust than implicated by the reported K d for AMH to AMHRII.…”

Müllerian inhibiting substance preferentially inhibits stem/progenitors in human ovarian cancer cell lines compared with chemotherapeutics

“…Human ovarian cancer cell lines-OVCAR-5 (55,56), 58), and IGROV-1 (59) cells-were maintained in the pediatric surgical research laboratories as previously described (4,21). Cells were treated with doxorubicin, cisplatin, paclitaxel (all from NovaPlus), MIS, or SP600125 (Sigma) (23). MIS was purified in our laboratory, and its bioactivity assessed in embryonic Müllerian duct regression assays (60,61).…”

Conserved Anti-Müllerian Hormone: Anti-Müllerian Hormone Type-2 Receptor Specific Interaction and Intracellular Signaling in Teleosts1

“…Forty hours after transfection, cells were incubated with SP600125 (Calbiochem -EMD Chemicals, Inc.) or with plasmin treated recombinant sea bass Amh at the indicated concentrations for 24 h in culture medium with 1% FBS. SP600125 is a c-Jun N-terminal kinase inhibitor II shown to activate AMHR2-mediated signal transduction [36]. Working dilutions were made fresh at time of use in culture medium with 0.1% added dimethylsulfoxide (DMSO) for every 10 µM of SP600125 as according to the manufacturer instructions.…”