Effects of hormones, methotrexate, and dactinomycin on benign trophoblast

Failed Methotrexate-Treated Ectopic Pregnancies: Clinicopathologic Correlations

Methotrexate (MTX) administration as an alternative to surgical therapy for unrupured ectopic pregnancies (EPs) has a 5-11% failure rate. The histologic findings in surgical specimens from patients for whom MTX therapy failed have not been exensively described. Review of pathology records from January 1991 through June 1996 revealed 12 MTX-treated tubal EPs that subsequently required surgical interention. Clinical data and histologic findings were compared with those from tubal EPs from maternalagend gestational-age-matched controls. Semiquantitative obervations of chorionic villous morphology were assessed by a senior pathologist unware of the treatment regimens. The average maternal age was 27 years and the mean gestational age was 9 weeks. Patients received one to two intramuscular injecions of MTX (50 mg/M2) and were followed up with serial serum betahuman chorinic gonadotropin (f-hCG) determinations. P-hCG levels fell from presentation to surgical intervention in 36.4% of MTX-treated patients, increased in 9.1%, and rose then fell in 54.5%. Peak r-hCG titers were significantly higher in MTX-exposed paients as compared with controls. There was no correlation between,3-hCG profile and villous morphology. Sixty-seven percent of MTX-treated EPs showed significant trophoblastic atypia as compared with 25% of control cases. Atypical villous trohoblasts had enlarged nuclei with irregular contours, smudged chromatin, and prominent nucleoli. There were no significant differences between failed MTX-exosed EPs and controls in terms of the presence or degree of villous necrosis, trohoblastic vacuolization, or embryonic development. Chorionic villous morphology in failed MTX-treated EPs showed no significant differences from that of nontreated EPs except for a trend toward increased trophoblastic atypia, features that may be confused with early gestational trophoblastic disease. Failed MTX-treated EPs may represent a subset of gestations that are resistant to MTX. As the uses of MTX are exanded to encompass the termination of early intrauterine pregnancies, the recogniion of possible treatmentrelated alterations in the histologic appearance of chorinic villi, trophoblasts, and implantation sites will be pertinent to avoid misdiagnosis.

Brain-derived neurotrophic factor/tyrosine kinase B signaling regulates human trophoblast growth in an in vivo animal model of ectopic pregnancy

Although medical treatment of unruptured ectopic pregnancy using methotrexate has been established, development of more potent and safer medical treatment is needed due to limited indications and side effects of methotrexate. Brain-derived neurotrophic factor (BDNF) signals through its receptor tyrosine kinase B (TrkB) to regulate the growth of malignant trophoblastic, choriocarcinoma cell. We investigated possible involvement of this signaling system in nonmalignant human trophoblast growth in both ectopic and intrauterine pregnancy. Here, we demonstrated the expression of BDNF in syncytiotrophoblasts and extravillous trophoblasts (EVTs) together with TrkB in cytotrophoblasts and EVTs in human placental villi during both normal and ectopic pregnancies. Treatment of cultured villous explants with soluble TrkB ectodomain or a Trk receptor inhibitor K252a suppressed cytotrophoblast differentiation by inhibiting EVT outgrowth reflected by decreased levels of an EVT marker, human leukocyte antigen-G. These inhibitors also decreased cytotrophoblast proliferation and cellular viability based on histopathological analyses and monitoring glucose metabolism, together with increased apoptosis in cytotrophoblasts based on in situ terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end-labeling and caspase-3/7 assays. After xenotransplantation of human placental villi into SCID mice as an in vivo model of ectopic pregnancy, treatment with K252a suppressed transplanted villi growth as reflected by decreased cytotrophoblast differentiation and proliferation, reduced tissue levels of chorionic gonadotropin-β, and increased apoptosis and caspase-3/7 activities. Thus, paracrine signaling by the BDNF/TrkB system is important for human cytotrophoblast differentiation, proliferation, and survival, and inhibition of BDNF/TrkB signaling in cytotrophoblasts could provide a novel medical treatment for ectopic pregnancy.

Treatment of tubal pregnancy by local injection of methotrexate after adrenaline injection into the mesosalpinx: a report of 25 patients

Twenty-five patients with a tubal pregnancy were treated by an injection of methotrexate (MTX) into the tubal swelling after vasoconstriction of the mesosalpinx with adrenaline. Twenty-four of the 25 patients had an uneventful clinical course. In one case, the tube ruptured despite falling serum human chorionic gonadotropin (hCG) concentrations. In 17 of 24 patients, the dose of 100 mg that was locally injected was sufficient. Seven patients were given additional systemic injections. In 3 of the 4 patients with high initial serum hCG levels (greater than 10.000 mIU/mL), the clinical course was uneventful. The side effects of MTX and adrenaline were minimal. Whether this way of treatment guarantees better chances of fertility in the future is unknown. Therefore a prospective, case-controlled study comparing the fertility rates in different ways of treatment is needed.

Methotrexate inhibition of normal trophoblasts in vitro

Methotrexate is a folic acid inhibitor useful in the treatment of gestational trophoblastic disease. Its effect on normal trophoblast in vitro was studied to help establish a minimum effective dose in vivo for the conservative treatment of ectopic pregnancy. In vitro inhibition of normal trophoblastic cell growth was measured after 48 hours of exposure to variable concentrations of methotrexate (10(-2) to 10(-9) mol/L) and rescue with leucovorin. A modification of Cotte's method of trophoblastic cell enrichment was used. Long-term (10 days) linear growth inhibition was observed at concentrations greater than 10(-5) mol/L. Leucovorin control cultures showed no inhibition of cell growth. The study demonstrates that methotrexate is effective in inhibiting normal trophoblastic cell culture growth in vitro at concentrations 1000 times those reported necessary to inhibit deoxyribonucleic acid synthesis in choriocarcinoma cell cultures.

Isolation of function human trophoblast cells and their partial characterization in primary cell culture

Human trophoblast isolation and cell culture procedures were examined to identify variables that enhance secretion of chorionic gonadotropin (HCG) in primary culture. Brief exposure of unminced first-trimester placental specimens to a solution of trypsin-EDTA-DNAse, and isolation of the dispersed cells after Ficoll-hypaque centrifugation yielded primary cultures that were high in HCG secretion and content of epithelial-like cells. The gradual decline in HCG level with time in monolayer culture in these presumptive trophoblast cells was retarded by treatment with theophylline and cyclic adenosine monophosphate. Exposure to methotrexate (MTX) did not increase HCG secretion in normal trophoblast cells, in contrast to a 5-fold stimulation by MTX in the JAR line of choriocarcinoma cells. Clusters of polygonal cells in primary culture progressively lost their capacity to secrete HCG and their epithelial-like morphology. However, they could be maintained as cell strains through approximately 15 passages over a period of 13 to 16 weeks.