MicroRNA Expression Profiling in Hydatidiform Mole for the Prediction of Postmolar GTN : MicroRNA Profile in Postmolar GTN

Objectives: The primary aim of the study was to identify miRNAs that were differentially expressed between complete hydatidiform moles (CHMs) that turned out to be gestational trophoblastic neoplasia (GTN) [GTN moles] and CHMs that regressed spontaneously after evacuation [remission moles]. The secondary aim was to study the profiles of miRNA expressions in CHMs. Methods: A case-control study was conducted on GTN moles and remission moles. We quantitatively assessed the expression of 800 human miRNAs from molar tissues using Nanostring nCounter. Results: From a pilot study, 21 miRNAs were significantly downregulated in GTN moles compared to the remission moles. Five of them (miR-566, miR-608, miR-1226-3p, miR-548ar-3p and miR-514a-3p) were downregulated for >4 folds. MiR-608 was selected as a candidate for further analysis on 18 CHMs (9 remission moles and 9 GTN moles) due to its striking association with malignant formation. MiR-608 expression was slightly lower in GTN moles compared to the remission moles, that is, 2.22 folds change [p = 0.063]. Conclusion: We identified 21 miRNAs that were differentially expressed between GTN moles and remission moles suggesting that miRNA profiles can distinguish between the two groups. Although not reaching statistically significant, miR-608 expression was slightly lower in GTN moles compared to remission moles.

Expression pattern Nanog is associated with the development of gestational trophoblastic neoplasia in Chinese women from Fujian province: a case-control study

BACKGROUND

Gestational trophoblastic disease (GTD) is a group of interrelated but distinct diseases and has a serious impact on the reproductive health of women. To analyze the expression of Nanog in GTD and to evaluate its potential to predict the development of gestational trophoblastic neoplasia (GTN).

METHODS

The study included 41 normal first-trimester placentas matched by gestational age to 53 regressed-hydatidiform-moles (rHMs), 56 malignant-HMs (mHMs) and 17 choriocarcinomas (CCAs) and evaluated the Nanog expression by immunohistochemistry. The chi-square test, ANOVA, Fisher's exact test and logistic regression were performed to assess the Nanog expression and clinical prognostic factors in GTD.

RESULTS

Compared to normal placenta levels, the Nanog expression was increased in GTD samples (p < .05). In HMs, Nanog expression was positively correlated with serum β-hCG levels,uterine size and theca-lutein cysts (p < .05). Compared with the low-risk metastatic group (Federation of Gynecology and Obstetrics (FIGO) score ≤ 6), the high-risk metastatic group (FIGO score >7) had higher Nanog expression (p = .030). Moreover, logistic regression analysis showed that the positive expression of Nanog had the highest risk of developing into GTN (OR = 4.764, p < .001).

CONCLUSIONS

Nanog is an independent predictor of clinical outcomes. It can also be a reliable predictor for GTN development from GTD.

Insights into the hyperglycosylation of human chorionic gonadotropin revealed by glycomics analysis

Human chorionic gonadotropin (hCG) is a glycoprotein hormone that is essential for the maintenance of pregnancy. Glycosylation of hCG is known to be essential for its biological activity. "Hyperglycosylated" variants secreted during early pregnancy have been proposed to be involved in initial implantation of the embryo and as a potential diagnostic marker for gestational diseases. However, what constitutes "hyperglycosylation" is not yet fully understood. In this study, we perform comparative N-glycomic analysis of hCG expressed in the same individuals during early and late pregnancy to help provide new insights into hCG function, reveal new targets for diagnostics and clarify the identity of hyperglycosylated hCG. hCG was isolated in urine collected from women at 7 weeks and 20 weeks' gestation. hCG was also isolated in urine from women diagnosed with gestational trophoblastic disease (GTD). We used glycomics methodologies including matrix assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass spectrometry (MS) and MS/MS methods to characterise the N-glycans associated with hCG purified from the individual samples. The structures identified on the early pregnancy (EP-hCG) and late pregnancy (LP-hCG) samples corresponded to mono-, bi-, tri-, and tetra-antennary N-glycans. A novel finding was the presence of substantial amounts of bisected type N-glycans in pregnancy hCG samples, which were present at much lower levels in GTD samples. A second novel observation was the presence of abundant LewisX antigens on the bisected N-glycans. GTD-hCG had fewer glycoforms which constituted a subset of those found in normal pregnancy. When compared to EP-hCG, GTD-hCG samples had decreased signals for tri- and tetra-antennary N-glycans. In terms of terminal epitopes, GTD-hCG had increased signals for sialylated structures, while LewisX antigens were of very minor abundance. hCG carries the same N-glycans throughout pregnancy but in different proportions. The N-glycan repertoire is more diverse than previously reported. Bisected and LewisX structures are potential targets for diagnostics. hCG isolated from pregnancy urine inhibits NK cell cytotoxicity in vitro at nanomolar levels and bisected type glycans have previously been implicated in the suppression of NK cell cytotoxicity, suggesting that hCG-related bisected type N-glycans may directly suppress NK cell cytotoxicity.

Human Placental Growth Hormone Variant in Pathological Pregnancies

Growth hormone (GH), an endocrine hormone, primarily secreted from the anterior pituitary, stimulates growth, cell reproduction, and regeneration and is a major regulator of postnatal growth. Humans have two GH genes that encode two versions of GH proteins: a pituitary version (GH-N/GH1) and a placental GH-variant (GH-V/GH2), which are expressed in the syncytiotrophoblast and extravillous trophoblast cells of the placenta. During pregnancy, GH-V replaces GH-N in the maternal circulation at mid-late gestation as the major circulating form of GH. This remarkable change in spatial and temporal GH secretion patterns is proposed to play a role in mediating maternal adaptations to pregnancy. GH-V is associated with fetal growth, and its circulating concentrations have been investigated across a range of pregnancy complications. However, progress in this area has been hindered by a lack of readily accessible and reliable assays for measurement of GH-V. This review will discuss the potential roles of GH-V in normal and pathological pregnancies and will touch on the assays used to quantify this hormone.

[The expression of EMT associated protein CK-18 and vimentin in gestational trophoblastic disease ]

OBJECTIVE

To analyze the expression and clinicopathologic features of epithelial to mesenchymal transition (EMT) associated protein of cytokeratin-18 (CK-18) and vimentin in gestational trophoblastic disease (GTD).

METHODS

Immunohistochemistry was used to determine theexpression of CK-18 and vimentin in normal pregnancy villis (39 cases), hydatidiform mole (HM) (33 cases) and gestational trophoblastic neoplasia (GTN) (invasive mole 27 cases and choriocarcinoma 5 cases).

RESULTS

The GTN group had significantly lower levels of CK-18 compared with the normal pregnancy villis group and the HM group (P<0. 01). Vimentin was weakly positive in all kinds of trophocyte. There was no significance among normal pregnancy villis, HM and GTN groups (P> 0. 05). In HM, expression level of CK18 was significantly lower with the increase of the pathological malignancy (P<0. 01). And in GTN, the expression of CK-18 was significantly lower with the increase of the tumor anatomy stage (P<0. 001).

CONCLUSION

The expression of CK-18 decreases with the increase of tropohblast malignancy, which indicates that CK-18 may be involved in malignant transformation of trophocytes and EMT may play an important role in the malignant transformation of GTN.

Important Role of the Dihydrouracil/Uracil Ratio in Marked Interpatient Variations of Fluoropyrimidine Pharmacokinetics and Pharmacodynamics

Dihydropyrimidine dehydrogenase (DPD) deficiency in patients causes severe toxicities in 5-fluorouracil/floxuridine (5-FU/FUDR) treatments. To determine the plasma dihydrouracil/uracil ratio (DUUR) as a potential index for setting 5-FU/FUDR doses, the authors conducted a prospective study on the relationships of the DUUR with 5-FU/FUDR pharmacokinetic and pharmacodynamic parameters. Forty gestational trophoblastic tumor (GTT) patients were treated with 30 mg/kg of 5-FU or prodrug FUDR during a 10-day cycle. The pretreatment DUURs of the patients were determined prior to the treatments, and plasma 5-FU and FUDR concentrations on day 1 of the test cycle were measured to calculate the corresponding pharmacokinetic parameters. The absolute neutrophil count (ANC) and human chorionic gonadotrophins (HCG/beta-HCG) were recorded as the efficacy indexes. The correlation of the DUUR with pharmacokinetic parameters and efficacy indexes was analyzed to look for a relationship between individual doses (in milligrams) and the varied DUUR. Pretreatment DUUR was significantly correlated with the corresponding plasma AUC (r > 0.80, P < .01), the plasma drug clearance (r > 0.78, P < .01), the ANC (r > 0.76, P < 0.01), and the decrease of HCG/beta-HCG levels (r > 0.5, P < 0.01). In addition, the charts for setting 5-FU/FUDR doses were designed for further validation in clinical trials. These findings indicate the important roles of the DUUR in remarkable interpatient variations of fluoropyrimidine pharmacokinetics and pharmacodynamics and propose a better index for setting individual 5-FU/FUDR doses based on interpatient variations in DPD levels.

Siglec-6 is expressed in gestational trophoblastic disease and affects proliferation, apoptosis and invasion

Sialic acid immunoglobulin-like lectin (Siglec)-6 is a transmembrane receptor that binds leptin. Leptin is an obesity-associated peptide hormone overexpressed in gestational trophoblastic disease (GTD). GTD encompasses several placental abnormalities that range from benign to malignant. Among GTD, molar placentas are characterized by excess proliferation, whereas gestational trophoblastic neoplasias (GTN) have characteristically aggressive invasion. We hypothesized that in GTD, Siglec-6 expression would increase with disease severity and that Siglec-6 and leptin would promote proliferation, inhibit apoptosis and/or promote invasion. Siglec-6 expression patterns were evaluated with particular attention to the diagnostic utility of Siglec-6 in GTD (controls: normal placentas (n=32), hydropic abortus placentas (n=7), non-GTD reproductive tract cancers (n=2); GTD: partial moles (PM; n=11), complete moles (n=24), GTN (n=6)). In normal placentas, Siglec-6 expression dramatically decreased after 8 weeks gestation. Complete molar placentas had significantly higher Siglec-6 expression than controls, but expression was not significantly different from PM. In GTN, Siglec-6 expression was low. These data suggest that Siglec-6 may have diagnostic utility for distinguishing complete moles from normal and hydropic abortus placentas. Functional studies in choriocarcinoma-derived BeWO cells demonstrated a complex interplay between Siglec-6 expression and leptin exposure. In cells lacking Siglec-6, leptin treatment promoted invasion, likely through interaction with LepR leptin receptor, without affecting proliferation or apoptosis. Siglec-6 expression promoted proliferation in a leptin-dependent manner, but protected cells from apoptosis and promoted invasion in a leptin-independent manner. We propose that Siglec-6 and leptin play a role in the aberrant properties characteristic of GTD, namely excess proliferation and invasion.

[Expressions of NF-κBp65 and IκBα in gestational trophoblastic disease and clinical significance]

AIM

To investigate the roles of nuclear factor κB p65 (NF-κBp65) and inhibitor of nuclear factor κB α (IκBα) in the development and metastasis of gestational trophoblastic neoplasia (GTN) by analyzing the expressions of NF-κBp65 and IκBα in normal early pregnancy villi and gestational trophoblastic diseases, and to reveal the relationship of NF-κBp65 and IκBα with age and clinical stage of GTN patients.

METHODS

The expressions of NF-κBp65 and IκBα were detected by immunohistochemistry in normal pregnancy villi (20 cases), hydatidiform moles (HM, 30 cases), invasive hydatidiform moles (IHM, 13 cases) and chorionic carcinomas (CCA, 15 cases).

RESULTS

NF-κBp65 expression was statistically different (P<0.05) between normal pregnancy villi and IHM (P=0.013), normal pregnancy villi and CCA(P=0.018), HM and IHM(P=0.026), HM and CCA (P=0.035). Differences in IκBα expression were statistically significant between normal pregnancy villi and IHM, normal pregnancy villi and CCA, HM and IHM, HM and CCA (P<0.01). The expressions of NF-κBp65 and IκBα were correlated to clinical stage (P=0.043, 0.042, P<0.05), but not to patients' ages. Spearman correlation analysis revealed that there was a negative association between the protein expressions of NF-κBp65 and IκBα in GTN (r=-0.403, P=0.034, P<0.05).

CONCLUSION

Up-regulated expression of NF-κBp65 and down-regulated expression of IκBα may be related to the development, invasion and metastasis of GTN. The expressions of NF-κBp65 and IκBα are negatively correlated in gestational trophoblastic tumor tissues.

PTEN and MDM2 expression in the prediction of postmolar gestational trophoblastic neoplasia

OBJECTIVE

To investigate the role of PTEN and MDM2 expression in hydatidiform mole in the prediction of postmolar gestational trophoblastic neoplasia (GTN).

STUDY DESIGN

A total of 145 cases of hydatidiform mole were diagnosed at the King Chulalongkorn Memorial Hospital from 1999 to 2010. Patients were classified into 2 groups: spontaneous remission and patients with postmolar GTN. Clinicopathologic features and immunohistochemical staining by PTEN and MDM2 were reviewed. The results were analyzed in correlation to the clinical characteristics and outcomes.

RESULTS

Of 145 recruited cases, 128 (88.3%) cases were complete hydatidiform mole (CHM) and 17 (11.7%) cases were partial hydatidiform mole (PHM). Postmolar GTN was clinically diagnosed in 42 cases (28.9%). The incidences of postmolar GTN following CHM and PHM were 29.7% and 23.5%, respectively. Mean age of the postmolar GTN group was significantly older than that of the remission group (31.2 vs. 27.8, p = 0.04). There was no significant difference of pathologic features between cases with remission and postmolar GTN. Immunoreactivity of PTEN and MDM2 were similarly present in trophoblastic cells of both CHM and PHM groups without significantly different patterns.

CONCLUSION

Immunohistochemical expression of PTEN and MDM2 in hydatidiform mole cannot predict molar malignant transformation.

[Expression and significance of LMP2 and PPM1A in gestational trophoblastic disease]

OBJECTIVE

To investigate the expression of low molecular mass polypeptide-2 (LMP2) and protein phosphatase 1A (PPM1A) in gestational trophoblastic disease and elucidate their predictive value in malignant transformation of hydatidiform mole.

METHODS

The expressions of LMP2 and PPM1A protein in 196 complete hydatidiform moles (in which 28 cases with malignant transformation), 7 invasive moles, 5 choriocarcinomas and 20 normal chorionic villus were detected with the method of EnVision immunohistochemistry. Their clinicopathologic data were retrospectively analyzed.

RESULTS

LMP2 and PPM1A protein expressed in cytotrophocytes, syncytiotrophoblast and extravillous trophoblast. The level of LMP2 expression in deteriorative hydatidiform mole was significantly higher than that in non-deteriorative hydatidiform mole or normal chorionic villus (6.79±2.38, 5.26±2.63 and 3.10±1.65, all P<0.01), while there were no difference compared with gestational trophoblastic neoplasms (6.42±2.68, P=0.113). The level of PPM1A expression was highest in normal chorionic villus, and decreased gradually in hydatidiform mole (non-deteriorative and deteriorative) and gestational trophoblastic neoplasms (6.30±2.98, 4.93±2.50, 4.43±2.04 and 3.33±2.06, all P<0.01); the level of PPM1A expression in deteriorative hydatidiform mole was significantly lower than that in non-deteriorative hydatidiform mole (P=0.001). The expression of LMP2 protein was correlated to theca lutein ovarian cyst, the expression of PPM1A protein was related with uterine size (P<0.05). While, there was no correlation between the expressions of the two proteins (P>0.05).

CONCLUSIONS

High expression of LMP2 and low expression of PPM1A might play an important role in the motility and invasiveness of trophoblast cells and malignant transformation of hydatidiform mole. Testing the expression of LMP2 and PPM1A in hydatidiform mole tissues of initial uterine evacuation might be have some reference significance in judging outcomes of hydatidiform mole.

Expression pattern alterations of the serine protease HtrA1 in normal human placental tissues and in gestational trophoblastic diseases

HtrA1 is a secreted protein which behaves as a molecular chaperone at low temperatures and as a serine protease at high temperatures. When the placenta escapes the normal growth control mechanisms, which are present during normal pregnancy, it may develop trophoblastic diseases, such as hydatidiform mole and choriocarcinoma. The aim of the study is to investigate the expression of HtrA1 in these gestational trophoblastic diseases and evaluate whether different HtrA1 expression might be associated with increasingly severe forms of disease. We used immunohistochemistry to assess the expression of HtrA1 in normal human placenta, hydatidiform mole (partial and complete) and choriocarcinoma. In addition to that we used the western blotting technique to quantify HtrA1 immunoreaction in normal human placentas. The most striking finding of our investigation is the decrease in immunostaining of this protease with increasing severity of gestational trophoblastic disease. For instance, in partial and complete moles HtrA1 is weakly expressed in the trophoblast. Moreover, absence of immunoreaction for HtrA1 is observable in the choriocarcinoma cells. In conclusion, we suggest that HtrA1 may play an important role in the pathogenesis and progression of hydatidiform moles and choriocarcinomas, and that HtrA1 may play an important role during the normal development of the placenta, as well as in trophoblastic diseases.

Gestational trophoblastic neoplasia—pathogenesis and potential therapeutic targets

Gestational trophoblastic neoplasia comprises a unique group of human neoplastic diseases that derive from fetal trophoblastic tissues and represent semiallografts in patients. This group is composed of choriocarcinoma, placental-site trophoblastic tumour, and epithelioid trophoblastic tumour, and many forms are derived from the precursor lesions, hydatidiform moles. Although most patients with gestational trophoblastic neoplasia are cured by chemotherapy and tumour resection, some patients suffer from metastatic diseases that are refractory to conventional chemotherapy. Therefore, new therapeutic regimens are needed to reduce the toxic effects associated with current chemotherapy and to salvage the occasional non-operable patients with recurrent and chemoresistant disease. Until the fundamental biology of gestational trophoblastic neoplasia becomes more clearly understood, development of a new treatment will remain empirical. This review will briefly summarise the recent advances in understanding the molecular aetiology of this group of diseases and highlight the molecules that can be potentially used for therapeutic targets to treat metastatic gestational trophoblastic neoplasia.

[MMP-2/TIMP-2 expression in the trophoblasts of patients with gestational trophoblastic disease]

OBJECTIVE

To explore the role of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of MMP-2 (TIMP-2) in the pathogenesis, development and prognosis of gestational trophoblastic disease (GTD).

METHODS

In situ hybridization and immunohistochemistry were utilized for MMP-2/TIMP-2 mRNA and protein detection in normal chorion of women with early gestation, hydatidiform mole, invasive mole, or choricarcinoma.

RESULTS

The results revealed that specific staining for mRNA and protein of MMP-2 and the expression of TIMP-2 was reduced in normal chorion of early gestation. In GTD ranging from hydatidiform mole, invasive mole to choricarcinoma, MMP-2 expression tended to increase while TIMP-2 expression underwent an invert change. The positivity rate of MMP-2 and TIMP-2 in gestational trophoblastic tumor group was higher than that of the normal chorion of early gestation group and hydatiform mole group (P<0.05 and P<0.001, respectively).

CONCLUSION

A disrupted balance between the activation and inhibition of MMP-2 plays a critical role in the pathogenesis, progression and metastasis of GTD.

Gestational trophoblastic diseases: 1. Pathophysiology of hyperglycosylated hCG

OBJECTIVE

Hyperglycosylated hCG (hCG-H) is a glycosylation variant of hCG produced by cytotrophoblast cells at implantation of pregnancy and in choriocarcinoma. We investigated the biological function of hCG-H in invasion in vitro and in vivo and the use of hCG-H antibodies in blocking tumorigenesis and cancer growth in vivo.

METHODS AND RESULTS

hCG-H accounts for 43% to 100% of total hCG immunoreactivity in the culture fluid of choriocarcinoma cell lines and 100% in primary cultures of pregnancy cytotrophoblast cells. We investigated the action of hCG and hCG-H on isolated cytotrophoblast cell primary cultures and on 3 different lines of choriocarcinoma cells cultured on Matrigel basement membrane inserts (culture models for assessing tumor invasion). The addition of hCG-H to medium significantly promoted invasion of membranes with both pregnancy and cancer cell line sources, while regular hCG had no significant effect. JEG-3 human choriocarcinoma cells were transplanted subcutaneously into athymic nude mice. Tumors rapidly formed. B152, mouse monoclonal antibody against hCG-H, and non-specific mouse IgG (control) were administered twice weekly once tumors were clearly visible. While a correlation between time and growth was observed with the control group (r(2)=0.97), no correlation was observed with the B152-treated mice (r(2)=0.15). B152 blocked tumor growth (t test, IgG vs. B152, P=0.003). In a second experiment, antibody B152 or IgG was administered to mice at the time of choriocarcinoma transplantation. B152 significantly inhibited tumorigenesis (t test P=0.0071).

CONCLUSIONS

hCG-H is a critical promoter in human cytotrophoblast and human choriocarcinoma cell invasion in vivo and in vitro, promoting tumor growth and invasion through an autocrine mechanism. hCG-H is a signal for choriocarcinoma cell invasion, making it a biological tumor marker. Antibodies against hCG-H block tumor formation and growth. Human or humanized antibodies against hCG-H may be useful in treating and managing choriocarcinoma and other gestational trophoblastic malignancies.

Expression of maspin in gestational trophoblastic disease

BACKGROUND

Maspin is a tumor suppressor gene whose expression is altered in neoplasia and malignancies of many tissues. In the human placenta, the maspin gene is expressed in trophoblastic cells and might act as an inhibitory regulator of trophoblastic invasion. Hence, in gestational trophoblastic disease (GTD), where there is increased propensity for invasion in the trophoblastic tissue, we hypothesized that maspin expression would be decreased. The present study aimed at investigating the expression of maspin in GTD and its prognostic significance.

METHODS

Using immunohistochemical staining, we firstly studied the expression of maspin in hydatidiform moles, with gestational age-matched normal first trimester placenta used as control. A total of 38 cases of hydatidiform moles were studied, including 20 complete moles (CM) and 18 partial moles (PM). Among them, 10 cases of the CM group and 8 cases of the PM group subsequently developed gestational trophoblastic neoplasia (GTN). Immunostaining was also performed on tissue from 4 cases of choriocarcinoma and 5 cases of placental site trophoblastic tumor. Reverse transcriptase-polymerase chain reaction (RT-PCR) was further performed on RNA extracted from 10 hydatidiform moles (5 with GTN and 5 without) and 6 normal first-trimester placentae.

RESULTS

In all tissue sections, nuclear expression of immunostaining signal was demonstrated, mainly in the cytotrophoblasts. The percentage of trophoblastic nuclei stained in both complete and partial moles was significantly lower than that in normal first-trimester placenta (P < 0.001). However, there was no significant difference in immunostaining between complete and partial moles (P > 0.05). There was also significantly lower expression of maspin in those cases subsequently developing GTN than those which did not (P = 0.01). Immunostaining on choriocarcinoma and placental site trophoblastic tumor showed reduced expression of maspin in all the tumor cells. Reverse transcriptase-polymerase chain reaction revealed that the expression of maspin was consistently down-regulated in all the hydatidiform mole samples.

CONCLUSIONS

Our results suggest that there is down-regulated expression of maspin in gestational trophoblastic diseases, and the down-regulation is more prominent in cases developing gestational trophoblastic neoplasia. This may play a role with prognostic significance in the pathogenesis and malignant transformation of hydatidiform moles.

Expression pattern of the activating protein-1 family of transcription factors in gestational trophoblastic lesions

The human placenta is an endocrine tissue with a unique capacity for rapid, but tightly controlled, proliferation and invasion. Gestational trophoblastic diseases (GTDs) are placental pathologies with endocrine activity and partially malignant potential and include hydatidiform moles, placental site nodules, and tumors such as placental site trophoblastic tumor and choriocarcinomas. The activating protein-1 (AP-1) family of transcription factors is composed of the cellular homologs of the Jun and Fos oncoproteins, which are immediately involved in cellular proliferation, differentiation, and invasion processes and in the regulation of endocrine genes. The expression pattern of the AP-1 family in the normal human placenta has been recently described, where most of the factors were found in the extravillous (invasive) trophoblast. Their systematic expression in GTD has not been studied thus far. For this reason in this study, we investigated the expression pattern of the AP-1 family in GTDs and compared it with the expression in normal placenta using immunohistochemistry with specific polyclonal antibodies against all members of the AP-1 family (JunB, JunD, c-Jun, c-Fos, FosB, Fra-1, Fra-2). Immunohistochemistry was performed on normal human placentas (positive control) and on 28 cases of GTD including 7 choriocarcinomas and 21 hydatidiform moles. In the normal placenta and in hydatidiform molar samples, most AP-1 factors (especially c-Jun, JunD, and Fra2) were expressed in the intermediate (extravillous) trophoblast. In addition, in molar lesions, strong expression was found in trophoblasts proliferating from the surface of villi. There was only a weak expression of JunB and Fra2 in small fractions of villous cyto- and syncytiotrophoblast nuclei. In choriocarcinomas, there was a strong expression for c-Jun, JunD, Fra1, and Fra2. The specific localization to extravillous trophoblasts and their expression pattern in GTDs indicate that the AP-1 family of transcription factors might be implicated in regulating proliferation and invasion of trophoblasts and play a role in the pathogenesis of GTDs.

Osteopontin Expression in Gestational Trophoblastic Diseases: Correlation With Expression of the Adhesion Molecule, CEACAM1

The human placenta is a complex tissue with multiple endocrine and nutritional functions and a unique capacity for rapid proliferation but tightly controlled invasion, differentiating it from malignant tumors. Osteopontin (OPN) is a glycoprotein of the extracellular matrix, which has been shown to mediate cellular migration and invasion and to contribute to tumorigenesis in several types of cancers. OPN also could be implicated in regulating implantation and placentation by promoting cellular migration and invasion in a placenta-specific fashion. We could demonstrate the expression pattern of OPN in the normal human placenta in which it is localized in the extravillous (intermediate) trophoblast and the villous cytotrophoblast. CEACAM1 is an adhesion molecule, which we have recently found to be expressed at the maternal-fetal interface of the normal placenta with a localization to the extravillous (invasive) trophoblast and in gestational trophoblastic disease (GTD) and also to be potentially implicated in trophoblast invasion and tumorigenesis. Both OPN and CEACAM1 have been shown to interact with integrin beta3. The purpose of this study was to investigate the expression pattern of OPN in GTD and to correlate it with the expression of CEACAM1. To analyze the expression of OPN, we performed immunohistochemistry on a total of 27 cases of GTD, including 21 hydatidiform moles and 6 choriocarcinomas, which had previously been characterized with respect to their CEACAM1 expression. Hydatidiform moles showed a positivity for OPN in villous cytotrophoblast and in the trophoblast proliferations on the villous surface. The strongest OPN expression could be observed in the choriocarcinomas with a heterogenous OPN expression pattern. CEACAM1 had shown similar results and was found to be expressed in choriocarcinoma. The expression pattern of osteopontin in gestational trophoblastic diseases indicates that it might play a role in the pathogenesis of GTD (possibly as a functional complex with CEACAM1 and integrin beta3) and might be useful as an additional diagnostic marker for such lesions.

The role of repeat uterine evacuation in the management of persistent gestational trophoblastic disease

OBJECTIVE

To evaluate the role of second (and third) uterine evacuation in the management of persistent gestational trophoblastic disease (GTD).

METHODS

This was an observational study of all cases registered over a 10-year period at the Trophoblastic Disease Centre at Weston Park Hospital, Sheffield. Five hundred and forty-four of 4050 women registered during 1991-2000 underwent a second uterine evacuation following a presumptive diagnosis of persistent GTD. The reason for evacuation, hCG level prior to the procedure, histological appearances of evacuated products and the clinical outcome (in terms of the need for chemotherapy) were determined.

RESULTS

After a second uterine evacuation 368 patients (68%) completed the follow-up programme without further evidence of persistent disease or need for chemotherapy. If the diagnosis of persistent GTD was confirmed solely on the basis of elevated hCG levels then 171 of 282 (60%) patients did not require chemotherapy. Chemotherapy was more likely where there was histological evidence of persistent trophoblastic disease and where the urinary hCG was >1500 IU/L at the time of the repeat evacuation. Twenty-eight of 60 patients (46%) undergoing a third evacuation required chemotherapy.

CONCLUSION

Second uterine evacuation can be a useful therapeutic option for patients with presumed persistent trophoblastic disease not mandating immediate chemotherapy, particularly where the hCG level is <1500 IU/L. Patients with documented persistent trophoblastic disease on histological examination of the second evacuation sample are more likely to require chemotherapy. Third evacuation is not now recommended.

p63 Expression Is Useful in the Distinction of Epithelioid Trophoblastic and Placental Site Trophoblastic Tumors by Profiling Trophoblastic Subpopulations

Human trophoblast is composed of a heterogeneous population of cells, which give rise to a variety of trophoblastic tumors and tumor-like lesions. In this report, we analyzed the expression pattern of the p63 gene, a transcription factor belonging to the p53 family, in different trophoblastic subpopulations and in trophoblastic lesions. p63 has various isoforms that are classified into two groups designated TA and DeltaNp63 isoforms. The TA isoforms have a p53-like suppressor function, whereas the DeltaNp63 isoforms exert an oncogenic effect. Based on immunohistochemistry and RT-PCR, it appears that cytotrophoblast expresses the DeltaNp63 isoform whereas chorionic-type intermediate trophoblast in the fetal membranes, placental site nodules, and epithelioid trophoblastic tumors expresses the TAp63 isoform. Intermediate trophoblast in the implantation site and placental site trophoblastic tumors does not express p63. Based on the expression patterns of p63 and the previously described expression patterns of other trophoblastic markers, including HLA-G, cytokeratin 18, hPL, and Ki-67, we developed an immunohistochemical algorithm to diagnose trophoblastic lesions. A validation set of 22 trophoblastic lesions and 34 nontrophoblastic tumors were classified correctly using this algorithm. In conclusion, the findings in this study demonstrate that different trophoblastic subpopulations and their related trophoblastic lesions are characterized by distinctive patterns of p63 expression. Recognizing these distinctive expression patterns helps to further elucidate the biology of trophoblast and can also provide a useful tool for the differential diagnosis of trophoblastic lesions.

c-mos Immunoreactivity Aids in the Diagnosis of Gestational Trophoblastic Lesions

C-mos is an important proto-oncogene involved in the mitogen-activating protein kinase pathway. This study was designed to explore c-mos immunoreactivity in gestational trophoblastic lesions and compare it with immunoreactivity in normal placentas as well as other gynecological lesions and germ cell tumors using antibody P-19. The immunohistochemical distribution of c-mos in 159 cases of gynecological lesions and 26 germ cell tumors using formalin-fixed, paraffin-embedded tissues was evaluated. The lesions included 45 (32 complete and 13 partial) hydatidiform moles, 17 choriocarcinomas, 5 placental site trophoblastic tumors, 18 squamous cell carcinomas and 5 adenocarcinomas of the cervix, 11 endometrial carcinomas, 9 ovarian carcinomas, 4 primary peritoneal papillary serous carcinomas, 9 low-grade endometrial stromal sarcomas, 4 epithelioid leiomyomas, 6 leiomyosarcomas, and 26 gem cell tumors (3 embryonal carcinomas, 5 yolk sac tumors, 6 immature teratomas, and 3 mature teratomas from the ovary; 9 testicular seminomas). Twenty-six normal placentas also were included for comparison. Among cases of gestational trophoblastic diseases, c-mos immunoreactivity was found in all hydatidiform moles and choriocarcinomas, but in none of the placental site trophoblastic tumors. The c-mos staining pattern was similar in trophoblastic diseases and normal placentas with strong expression in syncytiotrophoblast, moderate expression in villous intermediate trophoblast, and predominantly negative expression in implantation site intermediate trophoblast, chorionic-type intermediate trophoblast, and villous cytotrophoblast. All the nontrophoblastic tumors, including carcinomas, sarcomas, and germ cell tumors, were negative for c-mos expression. Immunohistochemical detection of c-mos is useful in differentiating choriocarcinoma from placental site trophoblastic tumor and nontrophoblastic tumors of the female genital tract that may sometimes cause problems in differential diagnosis.

GTT1/StarD7, a Novel Phosphatidylcholine Transfer Protein-like Highly Expressed in Gestational Trophoblastic Tumour:

We report the cDNA cloning and characterization of GTT1/StarD7, a novel gestational trophoblastic tumour gene, initially identified by its up-regulated expression in the choriocarcinoma JEG-3 cell line with respect to their nonmalignant counterpart, complete hydatidiform mole and normal trophoblastic tissue. Using the differential display fragment as a probe we screened placenta and HeLa cDNA libraries and isolated a clone carrying a 3315 bp insert (accession number AF270647). This cDNA encodes a protein of 295 amino acid residues with a molecular weight of approximately 34.7 kDa and a pI of 5.79. Computer-mediated homology search revealed that the deduced amino acid sequence had similarity to phosphatidylcholine transfer protein (PCTP) with a conserved StAR-related lipid transfer (START) domain extending between the amino acids 66 to 250. The GTT1 gene contains at least 9 exons spread nearly 30 kb on chromosome 2p12-2p11.2. Northern blot assays of total RNA derived from normal early placenta (NEP), complete hydatidiform mole (CHM) and JEG-3 cell line revealed a 3.5 kb mRNA expressed exclusively in the JEG-3 cell line. However, semiquantitative RT-PCR analysis performed with the same RNA samples demonstrated GTT1 expression throughout all of them with the highest level in JEG-3 cell line. Examination of GTT1 mRNA expression by semiquantitative RT-PCR assays in a series of tumour cell lines indicated wide-spread GTT1 expression with predominance in both choriocarcinoma JEG-3 and JAR cells, colorectal adenocarcinoma HT29 and hepatocellular carcinoma HepG2 cells. In conclusion, the highly GTT1 expression profile in JEG-3 and JAR cell lines and its lipid binding domain suggest that GTT1 may play an important role in the phospholipid-mediated signalling of trophoblastic tumour cellular events.

Co-expression of Fas (APO-1, CD95)/Fas ligand by BeWo and NJG choriocarcinoma cell lines

OBJECTIVE

Fas (CD95) is a transmembrane protein of the tumor necrosis factor receptor superfamily that induces apoptosis in susceptible cells on crosslinking by its ligand (FasL). The Fas loss of function and concurrent expression of its ligand (FasL) have been associated with malignant phenotype. In this study, we sought to investigate the hitherto undescribed expression of Fas and FasL on the immortalized human choriocarcinoma cell lines BeWo and NJG.

METHODS

Receptor and ligand expression was demonstrated using specific antibodies and multiple techniques including immunocytochemistry, confocal immunofluorescence microscopy, flow cytometry, immunoblots, and reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Data from this study indicate that human choriocarcinoma cell subtypes co-express both Fas and FasL. A specific cytoplasmic and membranous pattern of immunoreactivity was noted that was further confirmed at mRNA transcripts by RT-PCR. In addition, we provide evidence using flow cytometry that the Fas receptors are downregulated. The mean fluorescence intensities for NJG and BeWo were 1.47 +/- 0.5 and 1.59 +/- 0.4, while that for Fas-positive Jurkat cells was 25.6 +/- 3.1.

CONCLUSIONS

To our knowledge, this is the first report on the identification and constitutive co-expression of Fas and FasL in BeWo and NJG choriocarcinoma cells. Choriocarcinoma cells evade immune attack by downregulating the Fas receptor and by killing lymphocytes through expression of FasL. Taken together, our investigations suggest that the Fas/FasL system may represent a mechanism by which malignant trophoblasts become resistant to apoptosis, escape immune surveillance, and metastasize.

Minichromosome maintenance protein 7 expression in gestational trophoblastic disease: correlation with Ki67, PCNA and clinicopathological parameters

AIMS

To assess the proliferative activity of gestational trophoblastic disease (GTD) using one of the novel proliferation markers (MCM7) and to determine its prognostic value in hydatidiform mole (HM).

METHODS AND RESULTS

Immunohistochemical staining for MCM7 was performed on 122 samples of paraffin-embedded trophoblastic tissues including 22 normal first-trimester placentas, 12 term placentas, 12 spontaneous miscarriages (SM), 21 partial moles (PM), 44 complete hydatidiform moles (CM), and 11 choriocarcinomas (CCA). The correlations between the proliferative indices assessed by MCM7, proliferating cell nuclear antigen (PCNA) and Ki67 (MIB1) immunoreactivity as well as clinical progress were assessed. MCM7 immunoreactivity was found predominantly in the nuclei of cytotrophoblast and intermediate trophoblast and decreased with placental maturation. MCM7 expression was highest in CCA, followed by CM, PM, normal first-trimester placenta, SM and term placenta. MCM7 index was significantly higher in PM and CM than in SM (P = 0.007, P < 0.001) but not between PM and CM themselves (P = 0.560). Eighteen of the 65 patients with HM developed persistent trophoblastic disease (PTD) requiring chemotherapy. There was no significant difference in MCM7 indices between the patients who developed PTD and those who did not (P = 0.312). MCM7 indices correlated well with Ki67 (P = 0.002) but not with PCNA (P = 0.054) indices. MCM7 indices demonstrated less variability than PCNA and Ki67 and may be a better proliferation marker than the latter two.

CONCLUSIONS

We conclude that MCM7 is useful in differentiating molar and non-molar gestations but is not helpful in discriminating PM from CM or in predicting PTD.

Altered imprinting, promoter usage, and expression of insulin-like growth factor-II gene in gestational trophoblastic diseases

OBJECTIVE

We aimed to understand the involvement of imprinted genes in the pathogenesis of gestational trophoblastic diseases (GTD) such as hydatidiform mole (H-mole) and gestational trophoblastic tumors (GTT).

METHODS

An allelic-typing assay was performed using a PCR-RFLP-based method for identification of heterozygous informative cases. The usage of insulin-like growth factor-II (IGF2) promoters was examined by RT-PCR using promoter-specific primers. The mRNA expression of IGF2 and H19 was quantified using a densitometer.

RESULTS

The imprinting of IGF2 and H19 was maintained in all normal placenta tissues (n = 15) but relaxed in GTD (n = 47). Loss of imprinting (LOI) of IGF2 was in the order of GTT (57%) > complete H-mole (43%) > partial H-mole (25%). Similarly, LOI of H19 was in the order of GTT (40%) > complete H-mole (18%) > partial H-mole (0%). Promoter usage pattern of IGF2 changed with gestation stage of normal placentae and GTD. In normal placentae, the usage of promoter P1 was higher than that of P4 in the first trimester but lowered in the full term. H-mole and GTT predominantly used promoter P1 with relative silencing of promoter P4. Although normal early placenta and various GTD tissues showed the similar usage of IGF2 promoter P1, GTT tissues revealed the higher expression levels of IGF2 but a down-regulation of H19 relative to the normal early placentae.

CONCLUSIONS

These results suggest that LOI, deregulation of IGF2 promoters, and the altered expression levels of IGF2 and H19 genes might be associated with the progression of GTD.

Cytokeratin 20 as a biomarker of gestational trophoblastic disease: diagnostic and prognostic significance

OBJECTIVES

This study was designed to examine whether cytokeratin 20 (CK20) is expressed in molar pregnancies and may therefore be used in the diagnosis of gestational trophoblastic disease (GTD). The potential of CK20 expression in predicting the evolution and the prognosis of the different subtypes of GTD was also assessed.

METHODS

A total of 48 samples were studied for CK20 expression by RT-PCR methodology. Among these, 24 samples were obtained by curettage of the uterine cavity of patients diagnosed with hydatidiform mole (14 complete moles and 10 partial moles), 4 samples were obtained from choriocarcinoma cell lines (2 JAR and 2 JEG), and 20 samples were of normal trophoblast (control group) obtained from patients that underwent elective termination of pregnancy.

RESULTS

Expression of CK20 was identified in all the samples of complete mole (CM), all choriocarcinoma cell lines, and 50% of the patients with partial mole (PM). None of the preparations of normal trophoblastic tissue from the control group expressed the CK20. A significant difference (P < 0.00001) was found in CK20 expression between samples of patients with GTD and control samples. Comparison between CK20 expression in CMs and PMs revealed a significantly more frequent expression of CK20 in CMs (P = 0.006). More than 50% of the patients with PMs that were positive for CK20 had an invasive evolution.

CONCLUSIONS

In our opinion, CK20 may assist in distinguishing between molar and normal trophoblastic tissue and may be considered a marker of GTD. In cases in which pathological classification of different subtypes of GTD is in doubt, CK20-positive expression is suggestive for a CM whereas CK20-negative is more indicative for PM.

[Expression of epidermal growth factor receptor in gestational trophoblastic tumours]

OBJECTIVE

To investigate the expression of epidermal growth factor receptor (EGFR) in gestational trophoblastic tumours and its clinical significance.

METHODS

Placentas of 10 normal early pregnancies, 20 molar pregnancies, 10 samples from invasive mole and 8 samples of choriocarcinoma were used for the study. EGFR expression was evaluated by immunohistochemistry using monoclonal antibody.

RESULTS

EGFR was expressed both in normal chorionic villi and tissues of trophoblastic tumours. EGFR was expressed more strongly in normal chorionic villi and non-malignant transformed hydatidiform mole than in malignant transformed molar pregnancies and malignant trophoblastic tumours (P < 0.05). Univariate and multivariate analysis indicated that EGFR immunostaining intensity was significantly related to the clinical stage in malignant trophoblastic tumours (P = 0.026, OR = 9.874).

CONCLUSION

EGFR expression could be used as an index for prediction of malignant transformation of hydatidiform mole and staging of malignant trophoblastic tumours.