153. COMBINATION METHOTREXATE AND EPIDERMAL GROWTH FACTOR RECEPTOR INHIBITION AS A NOVEL MEDICATION-BASED CURE OF ECTOPIC PREGNANCIES
U. Nilsson A , T. G. Johns B , T. Wilmann A , Y. Gao A , C. Whitehead A , E. Dimitriadis C , E. Menkhorst C , B. Saglam A , S. Greenall B , A. Horne D and S. Tong AA Ritchie Centre, Monash Institute of Medical Research, Translational Obstetrics Group, Clayton, VIC, Australia.
B Monash Institute of Medical Research, Centre for Cancer Research, Clayton, VIC, Australia.
C Prince Henrys Medical Research Institute, Uterine Biology Group, Clayton, VIC, Australia.
D The Queen’s Medical Research Institute, University of Edinburgh, Centre for Reproductive Biology, Edinburgh, UK.
Reproduction, Fertility and Development 22(9) 71-71 https://doi.org/10.1071/SRB10Abs153
Published: 6 September 2010
Abstract
Ectopic pregnancies are serious gynaecological emergencies that can cause fatal haemorrhage. Most are treated surgically. Given the placenta is heavily reliant on Epidermal Growth Factor Receptor (EGFR) signaling, we set out to develop a medication-based treatment of ectopics using combination gefitinib (EGFR inhibitor) and methotrexate (folate antagonist). Both drugs are well tolerated and available in tablet form. We used in vitro and in vivo approaches to test the ability of gefitinib and methotrexate to regress placental tissue, and to explore molecular mechanisms. In vitro assays included immunohistochemistry (EGFR staining) western blot (EGFR phosphorylation), cell viability assays (Cell-Titre Blue, LDH cytotoxicity assay, xCELLigence system), apoptosis assays (PCR, FACS of M30 antibody) and The Bioplex Platform (phosphorylation of the EGFR pathway). JEG-3 xenografts were used to assess regression of placental tissue in vivo, where serum hCG was also measured (ELISA). EGFR was highly expressed in placentae from ectopic pregnancies. Combination treatment was supra-additive in inducing cell death of placental tissue in vitro, with >70% cell death by 48 hours (Syncytialised BeWos, JEG-3 and 1st trimester trophoblast). This supra-additive effect was demonstrated in both end point assays (cell viability) and regular monitoring using The xCELLigence system. Gefitinib potently blocks EGFR phosphorylation in placental tissues in vitro (Western blot). Both drugs may be converging to inhibit Akt phosphorylation (Bioplex analysis). Combination treatment increases apoptosis (FACS of M30 antibody). In vivo, Gefitinib or MTX as single agents induced significant decrease in xenograft tumour volume in a dose dependent manner (n ≤ 5 mice per treatment). However, combining these drugs was supra-additive in decreasing xenograph tumour volume and weight. Serum hCG in mice was lowest with combination treatment. Combination gefitinib and methotrexate potently regresses placental tissue. It may be a novel therapeutic approach to cure ectopic pregnancies, potentially replacing surgery with tablets.
