ABSTRACT
Mullerian Inhibiting Substance (MIS), a biological modifier that causes regression of Mullerian ducts in male embryos, is effective as a single agent in vitro and in vivo against human and mouse ovarian cancer cell lines expressing MIS type II receptor; however, little is known about how recombinant human MIS (rhMIS), now being scaled for preclinical trials, could be used in combination with cytotoxic or targeted chemotherapeutic agents. Mouse serous and endometrioid ovarian carcinoma cell lines were tested in vitro against rhMIS alone and with doxorubicin, paclitaxel, or cisplatin as agents in clinical use. Because MIS releases FK506 binding protein (FKBP12), which activates the mammalian target of rapamycin (mTOR) downstream of Akt, rhMIS and rapamycin combinations were tested. MIS increases p16 protein levels, and 5'-Aza-2'-deoxycytidine (AzadC) induces p16 mRNA; therefore, they were used in combination in vitro and in vivo with a human ovarian cancer cell line. A paclitaxel-resistant human ovarian cancer cell line and its parental line both respond to rhMIS in vitro. Additivity, synergy, or competition was observed with MIS and rapamycin, AzadC, doxorubicin, cisplatin, and paclitaxel, suggesting that MIS in combination with selective targeted therapies might achieve greater activity against ovarian cancer than the use of each individual agent alone. These assays and statistical analyses could be useful in selecting rhMIS and chemotherapeutic agent combinations that enhance clinical efficacy and reduce toxicity.
Subject(s)
Glycoproteins/therapeutic use , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/pathology , Testicular Hormones/therapeutic use , Animals , Anti-Mullerian Hormone , Apoptosis/drug effects , Azacitidine/analogs & derivatives , Azacitidine/pharmacology , Cell Line, Tumor , Decitabine , Drug Resistance, Neoplasm/drug effects , Female , Humans , Immunoglobulin G/therapeutic use , Melphalan/therapeutic use , Mice , Mice, Nude , Ovarian Neoplasms/metabolism , Paclitaxel/therapeutic use , Receptors, Peptide/metabolism , Receptors, Transforming Growth Factor beta , Xenograft Model Antitumor AssaysABSTRACT
PURPOSE: Müllerian inhibiting substance (MIS) causes Müllerianduct regression in mammalian, avian, and reptilian embryos; MIS also inhibits growth in vitro of Müllerian-derived cell lines and primary cells from human ovarian carcinomas. We hypothesize that highly purified MIS delivered parenterally inhibits ovarian cancer in vivo. EXPERIMENTAL DESIGN: To test the efficacy of highly purified MIS against ovarian cancer cell lines in vivo, we treated immunosuppressed mice with MIS after implanting OVCAR 8 or IGROV 1 human ovarian cancer cells beneath the renal capsules and measured tumor volume over time. Animals were treated with daily injections of 10 micro g of purified exogenous recombinant human MIS or by endogenous MIS secreted from cells growing on biodegradable mesh. RESULTS: The average graft size ratio (change in size compared with starting size) of the OVCAR 8 tumor implants was larger in the control animals than in animals treated for 2 weeks (P < 0.019) or 3 weeks (P < 0.001) with parenteral MIS, or after treating with MIS produced from transfected cells, which impregnated the biodegradable mesh (P = 0.02). The average graft size ratio of the IGROV 1 tumors was also larger in the control animals than in those treated with injected MIS (P = 0.0174). CONCLUSIONS: Highly purified recombinant human MIS, delivered parenterally, or MIS produced endogenously causes inhibition of human ovarian cancer cell lines in vivo, providing convincing preclinical evidence to support the use of MIS as a parenteral agent for the treatment of ovarian cancer.
