A rare case of combined placental site trophoblastic tumour with mature cystic teratoma and mixed germ cell tumour in the testis

A 20-year-old male presented with persistent right testicular pain. Following ultrasound detection of testicular nodules and biopsy for intraoperative consultation which yielded germ cell tumour, he underwent radical orchidectomy. A predominantly whitish cyst and a lobulated, variegated nodule were identified. Histology showed a mature cystic teratoma with a focus of infiltrative epithelioid cells containing eosinophilic cytoplasm and pleomorphic nuclei, invading ectatic vessel wall associated with fibrinoid change. These cells were positive for cytokeratin, human placental lactogen and inhibin, while negative for Melan-A, p63 and alpha-fetoprotein, consistent with placental site trophoblastic tumor (PSTT). The variegated nodule was a mixed germ cell tumour composed of embryonal carcinoma and immature teratoma. Aside from choriocarcinoma, primary trophoblastic tumors such as PSTT, which are derived from intermediate trophoblasts, are extremely rare in the testis. Aside from a case of pure testicular PSTT, 2 other cases have been described in association with germ cell tumour, of which one is a mature teratoma with PSTT that demonstrated gain of chromosome 12p. The other presented with PSTT in retroperitoneal recurrence of a testicular mixed germ cell tumour. We discussed the features of this tumour in the testis and important differentials in its diagnosis.

[Construction and identification of a stable eukaryotic expression system for F10 gene]

OBJECTIVE

To detect the transcriptional level of a novel gene F10 associated with the pathogenesis of hydatidiform mole in human cell lines and screen the cell lines with low F10 expression to construct a stable eukaryotic expression system for F10 gene.

METHODS

The expression level of F10 mRNA was detected with fluorescent quantitative PCR in A549, 16HBE, Bel7402, HIC, HepG2, 293, PC and MGC cell lines. A549 cell line was transfected with plasmid pRc-CMV2-F10 via electroporation to allow stable F10 expression, and the positive cell clones were selected by G418. The insertion and expression of F10 gene in the A549 cells was analyzed using fluorescent quantitative PCR.

RESULTS

F10 mRNA was expressed differentially in these cells lines, and the Bel7402 cells, PC and MGC cells showed the highest F10 mRNA expression, followed by HepG2 and HIC cells and further by 293 cells, and 16HBE and A594 cells had the lowest expression. After transfection, A594 cells showed genomic integration of F10 gene and high expression level of F10 mRNA.

CONCLUSION

The pulmonary carcinoma cell line A549 with stable expression of F10 gene has been established, which may facilitate further study of the biological functions of F10 gene.

Absence of Y chromosome in human placental site trophoblastic tumor

Placental site trophoblastic tumor is a neoplasm of extravillous intermediate trophoblast at the implantation site, preceded in the majority of cases by a female gestational event. Our pilot investigation suggested that the development of this tumor might require a paternally derived X chromosome and the absence of a Y chromosome. Twenty cases of placental site trophoblastic tumor were included in this study. Genotyping at 15 polymorphic loci and one sex determination locus was performed by multiplex PCR followed by capillary electrophoresis. X chromosome polymorphisms were determined by PCR amplification of exon 1 of the human androgen receptor gene using primers flanking the polymorphic CAG repeats within this region. Genotyping at 15 polymorphic loci was informative and paternal alleles were present in all tumors, confirming the trophoblastic origin of the tumors. The presence of an X chromosome and the absence of a Y chromosome were observed in all tumors. Among 13 cases in which analysis of the X chromosome polymorphism was informative, all but one demonstrated at least two X alleles and seven cases showed one identifiable paternal X allele. These results confirm a unique pathogenetic mechanism in placental site trophoblastic tumor, involving an exclusion of the Y chromosome from the genome and, therefore, a tumor arising from the trophectoderm of a female conceptus. As epigenetic regulations of imprinting during X chromosome inactivation are of significant biological implications, placental site trophoblastic tumor may provide an important model for studying the sex chromosome biology and the proliferative advantage conferred by the paternal X chromosome.

The risk of persistent trophoblastic disease after hydatidiform mole classified by morphology and ploidy

OBJECTIVE

Hydatidiform mole can be classified by histopathologic characteristics and by genetic constitutions and most complete moles are diploid, whereas most partial moles are triploid. We investigated the concordance between these two classifications, characterized moles with conflicting classifications, and compared the ability of the two classifications to discriminate between patients with and without a substantial risk of persistent trophoblastic disease.

METHODS

294 cases of consecutively collected hydropic placentas clinically suspected of hydatidiform mole made the basis of this retrospective study. We determined the ploidy and reviewed the original histopathologic material in all cases. Data on possible chemotherapy were collected for each patient.

RESULTS

270 of the conceptuses were histopathologically classified as hydatidiform mole. Among the 24 conceptuses classified as non-molar miscarriage, 20 were triploids, 2 were diploid androgenetic and 2 were diploid biparental. In 23% of the conceptuses, the histopathologic and genetic classifications were conflicting. 5% of the patients with hydropic placentas classified as partial mole encountered persistent trophoblastic disease; however, the genome was diploid in all these moles. None of 131 patients with a triploid hydropic gestation encountered persistent trophoblastic disease.

CONCLUSION

As full concordance between the histopathologic and the genetic classifications was not found, we believe that features beyond the genetic constitution influence the development of morphologic features in hydatidiform moles. We recommend that gestations suspected of hydatidiform mole are subjected to histopathologic examination. If hydatidiform change and trophoblastic hyperplasia are identified, the ploidy should be used to identify patients with a high risk of persistent trophoblastic disease.

[Association of the novel hydatidiform mole-related gene F10 with the invasiveness of trophoblastic tumor]

OBJECTIVE

To study the expressions of the novel gene F10 associated with hydatidiform mole in different trophoblastic tumors and explore the relation of F10 expression with the invasiveness of malignant trophoblastic tumor.

METHODS

In situ hybridization was used to study the expression of F10 in 12 cases of hydatidiform mole, 6 cases of invasive mole, and 8 cases of choriocarcinoma.

RESULTS

F10 mRNA was positive in all cases of hydatidiform mole, invasive mole, and choriocarcinoma, and the expression intensity significantly increased in the order of hydatidiform mole, invasive mole and choriocarcinoma (P<0.001).

CONCLUSION

The expression of F10 gene may relate to the occurrence and invasiveness of trophoblastic tumor, with possible involvement in the invasion or malignant changes of trophoblastic cells.

Differential expression of insulin-like growth factor binding protein 1 and ferritin light polypeptide in gestational trophoblastic neoplasia

BACKGROUND

Hydatidiform mole (HM), the most common type of gestational trophoblastic diseases, can be considered as placenta with abnormal chromosome composition with potential of malignant transformation. Few biologic markers can predict subsequent development of persistent gestational trophoblastic neoplasia (GTN) requiring chemotherapy.

METHODS

Suppression subtractive hybridization (SSH) combined with cDNA microarray was used to compare the differential expression pattern of HM that spontaneously regressed and that subsequently developed metastatic GTN. Tissue-specific chips were constructed from the subtracted cDNA libraries, followed by cDNA microarray analysis. Verification by quantitative RNA analysis by real-time polymerase chain reaction (PCR) and immunohistochemical analysis was performed in 23 genotyped complete HM.

RESULTS

Sixteen differentially expressed transcripts were identified. Quantitative RNA analysis confirmed down-regulation of ferritin light polypeptide (FTL) (P = 0.037) and insulin-like growth factor binding protein 1 (IGFBP1) (P = 0.037) in HM that subsequently developed GTN when compared with those HM that regressed. Immunohistochemical analysis further confirmed reduced IGFBP1 protein (P = 0.03) expression in HM that developed GTN.

CONCLUSIONS

Findings showed that reduced expression of genes related to cell invasion and immunosuppression, especially FTL and IGFBP1, were associated with development of GTN, and this finding may provide a better understanding of the pathogenesis of GTN. The potential application of FTL and IGFBP1 in management of patients with HM should be explored.

Placental site trophoblastic tumor of the uterine cervix occurring from undetermined antecedent pregnancy

A cervical polyp complicated by severe hemorrhage was removed from a 43-year-old Japanese woman (gravida 0), who had undergone tubectomy on the right side 10 years previously. The polyp was diagnosed by immunohistochemical studies as placental site trophoblastic tumor of the cervix, but no metastatic foci were found in any other uterine site. The tumor was further demonstrated by PCR polymorphisms to possess two genomic DNA of the patient and her husband. Serum beta-hCG and urinary hCG titers were both low, which rapidly fell to 0.8 mIU/mL after a total hysterectomy and remained 0.2 mIU/mL after dismission. She has been uneventful for 3 years.

Stimulation of hCG protein and mRNA levels in trophoblast tumour cells Jeg3 and BeWo by glycodelin A

The placental hormone human chorionic gonadotropin (hCG) represents a marker for the differentiation process of cytotrophoblast cells into syncytial trophoblasts and is also found in the serum and urine of patients with malignant trophoblastic diseases. During pregnancy, serum concentration curves of hCG and glycodelin A show a similar course. The main source of hCG is the trophoblast and trophoblast cells in vitro show an increased hCG release if treated with glycodelin A. In addition, hCG is a tumour marker for chorion carcinoma cells. We investigated the effect of native and recombinant glycodelin on the trophoblast tumour cells Jeg3 and BeWo and the role of expression plasmids of glycodelin A in the same cells. Our study shows that glycodelin A stimulates the secretion of hCG protein in Jeg3 trophoblast tumour cells in a time- and dose-dependent manner. Our results were confirmed on the mRNA level by real-time RT-PCR. The effect of glycodelin A on hCG mRNA regulation is time- and dose-dependent. We observed an increase of hCG mRNA copy numbers after glycodelin A treatment leading to a higher hCG protein production. Glycodelin A had no effect on BeWo trophoblast tumour cells, suggesting that production of hCG is not regulated by glycodelin A in these cells.

Clinicopathologic profile of gestational trophoblastic disease

Much debate exists on factors predicting the development of persistent gestational trophoblastic disease (pGTD). Diagnosis is still limited by following persistently elevated or rising postevacutation beta-human chorionic gonadotropin (beta-hCG) titers. The aim of the present work was to evaluate the hypothesis that the presence of c-erbB-2 oncogene amplification and expression, in combination with parameters such as DNA-content and karyotype of the sex chromosomes, confer an increased risk of developing pGTD. Clinicopathological characteristics were evaluated in 36 cases of gestational trophoblastic diseases (GTD) and analyzed for c-erbB-2 amplification and protein p185 expression using differential polymerase chain reaction (DPCR) and immunohistochemical (IHC) techniques. The DNA-content was determined by image analysis on Feulgen stained nuclear cell preparations and karyotyping for XY chromosomes was performed by fluorescence in situ hybridization (FISH). The data was correlated with histopathological characteristics of GTD. Seventy-five percent (n = 27) of the examined cases showed spontaneous regression after evacuation, including 2 patients who received additional chemotherapy. Twenty-five percent (n = 9) resulted in a persistent or metastatic disease. The median time between antecedent pregnancy and GTD was 45.4 months. Complete remission was achieved in all patients with pGTD after administration of chemotherapeutic agents or adjuvant surgical procedures. Cases with cerbB-2 amplification and expression in combination with DNA hyperploidy showed higher proliferation and more aggressive behavior (2 complete hydatidiform moles with lung and liver metastases, 2 invasive moles and 1 choriocarcinoma). XY karyotype was evident in the choriocarcinoma and in 2 complete hydatidiform moles with advanced stage and DNA hyperploidy. From these results we conclude that c-erbB-2 amplification and/or protein expression in combination with DNA-content show a significant correlation with the proliferative and aggressive potential of GTD, suggesting their combined use as a possible marker for pGTD.

Molecular genetic analysis of placental site trophoblastic tumors and epithelioid trophoblastic tumors confirms their trophoblastic origin

Trophoblastic tumors represent a unique group of human neoplasms because they are derived from fetal tissue. Except for choriocarcinoma, the neoplasms that develop from human trophoblast are poorly characterized. Placental site trophoblastic tumors and epithelioid trophoblastic tumors are thought to arise from intermediate (extravillous) trophoblasts based on histopathological studies, but direct molecular evidence of a trophoblastic origin has not been established. In this study, we performed molecular analysis in an attempt to confirm their presumable trophoblastic origin. We demonstrated that such tumors contain a Y-chromosomal locus and/or new (paternal) alleles not present in adjacent normal uterine tissue in all 31 informative cases. Loss of heterozygosity was found in 60% of tumors and all 42 tumors assessed contained wild-type K-ras. All of the trophoblastic tumors were heterozygous in at least 1 of 10 single-nucleotide polymorphism markers studied in contrast to homozygosity in all 10 single-nucleotide polymorphism markers in most complete hydatidiform moles indicating that these tumors are not related to complete hydatidiform moles. This study provides the first molecular evidence that placental site trophoblastic tumors and epithelioid trophoblastic tumors are of fetal (trophoblastic) origin.

Treatment of metastatic invasive moles in two husband-side sisters-in-law. Case reports and review of literature

PURPOSE OF INVESTIGATION

The treatment of "high risk" persistent trophoblastic disease (PTD) consists of poly-chemotherapy. This policy probably will lead to overtreatment of some patients. Also, familiar molar pregnancies through the paternal line are unknown in the literature up till now.

METHODS

We describe two cases of "high risk" PTD in two husband-side sisters-in-law, in which poly-chemotherapy was stopped after histology became available and showed invasive metastatic mole.

CONCLUSION

It should be stressed that treatment decisions should be made based on the concept of "high" or "low" risk PTD, but if histology becomes available, chemotherapy might be less aggressive in cases of invasive mole. If invasive mole could be familiar through the paternal line remains unclear with the current knowledge of genetics in trophoblastic disease.

Detection of beta-subunit human chorionic gonadotropin mRNA in the peripheral blood of patients with nonmetastatic gestational trophoblastic disease

OBJECTIVE

The aim of this study was to detect beta-subunit human chorionic gonadotropin (beta(h)CG) mRNA in the peripheral blood samples of patients with nonmetastatic gestational trophoblastic disease (GTD) undergoing hysterectomy.

METHODS

Heparinized peripheral blood samples were obtained from four patients with nonmetastatic GTD before, during, and after hysterectomy. The beta(h)CG mRNA expression was examined by reverse transcriptase-polymerase chain reaction using beta(h)CG primers. The expression of beta(h)CG mRNA was quantified using a densitometer.

RESULTS

Beta(h)CG expression was detected in all patients before and during hysterectomy. The expression of beta(h)CG mRNA during operation was so high that it could not be quantified using densitometer. The expression decreased rapidly after operation.

CONCLUSIONS

Disseminated trophoblastic cells are present in the peripheral blood even in cases without metastasis. Trophoblastic cells circulating in the peripheral blood can be reduced by surgical intervention.

Molecular basis of gestational trophoblastic diseases

Gestational trophoblastic disease (GTD) encompasses a diverse group of lesions with specific pathogenesis, morphological characteristics and clinical features. The modified World Health Organization-classification of GTD includes complete and partial hydatidiform mole, invasive mole, choriocarcinoma, placental site trophoblastic tumor, epithelioid trophoblastic tumor, exaggerated placental site, and placental site nodule. The various forms of gestational trophoblastic disease can be defined and related to discrete pathologic aberrations occurring at different stages of trophoblastic differentiation. Some of these lesions are true neoplasms, whereas others represent abnormally formed placentas with a predisposition for neoplastic transformation of the trophoblast. Except hydatidiform moles in which the cytogenetic studies have been extensively reported, the pathogenesis of other trophoblastic lesions is poorly understood. Recent studies have shed light on the molecular mechanisms of trophoblastic function, especially as it relates to trophoblastic disease. This review will focus on these advances with special emphasis on the pathogenesis of each specific form of GTD. In addition, the morphology and clinical behavior of each of these entities will be briefly discussed.

Differential gene expression in premalignant human trophoblast: role of IGFBP-5

Tumorigenesis results from genetic alterations that occur in a stepwise manner giving rise to cells with increasingly cancer-like characteristics. We used in vitro propagated first trimester human extravillous trophoblast (EVT) cells to identify genetic changes responsible for the transition of the EVT from a normal to premalignant stage. The model used consisted of a normal invasive EVT (HTR8) cell line and its premalignant derivative (RSVT2/C) generated by transfection with the SV40 Tag and selected using a forced crisis regimen. RSVT2/C display increased proliferative, migratory and invasive behavior, unresponsiveness to anti-proliferative and anti-invasive signals of TGFbeta and a deficiency in gap junctional intercellular communication. These cells, however, were unable to form colonies on soft agar or tumors in nude mice and are thus defined as premalignant. Differential display revealed 18 gene sequences, 7 with unknown and 11 with known identity, showing altered expression between the normal HTR8 and premalignant RSVT2/C cell lines. The known sequences include the potential tumor suppressors insulin-like growth factor binding protein (IGFBP)-5 and fibronectin (FN) and potential protooncogenes such as chromokinesin (KIF4), alternative splicing factor (SF2), dynein, DNA polymerase epsilon (DNApol epsilon) and NF-kappaB activating kinase (NAK). The role of the remaining 4 genes upregulated in the premalignant EVT is presently unknown and these are FK506 binding protein (FKBP) 25, histone protein (HP1Hs)-gamma, nucleoporin (Nup) 155 and an 82 kDa acidic human protein. The functional role of IGFBP-5 was examined in the control of proliferation, migration and invasiveness of RSVT2/C cells measured in vitro. IGFBP-5 alone had no effect on these properties of RSVT2/C cells. Furthermore, unlike normal EVT cells, RSVT2/C cells exhibited refractoriness to the migration stimulating signals of IGF-II, which was explained by the loss or downregulation of the IGF type 2 receptor (IGF-R2). RSVT2/C cells, however, expressed the IGF type 1 receptor (IGF-R1) and responded to IGF-I by increased proliferation. This response was blocked with increasing concentrations of IGFBP-5. These results suggest that the loss of IGFBP-5 and possibly IGF-R2, both of which can sequester IGF-I from IGF-R1, permits unhindered proliferation of the premalignant EVT in an IGF-I rich environment of the fetal-maternal interface. The functions of the other differentially expressed genes, some of which are essential for cell cycle progression or cell survival require further investigation.

Expression of TGF-beta signaling genes in the normal, premalignant, and malignant human trophoblast: loss of smad3 in choriocarcinoma cells

We had earlier shown that TGF-beta controls proliferation, migration, and invasiveness of normal human trophoblast cells, whereas premalignant and malignant trophoblast cells are resistant to TGF-beta. To identify signaling defects responsible for TGF-beta resistance in premalignant and malignant trophoblasts, we have compared the expression of TGF-beta signaling molecules in a normal trophoblast cell line (HTR-8), its premalignant derivative (RSVT2/C), and two choriocarcinoma cell lines (JAR and JEG-3). RT-PCR analysis revealed that all these cell lines expressed the mRNA of TGF-beta1, -beta2, and -beta3, TGF-beta receptors type I, II, and III, and post-receptor signaling genes smad2, smad3, smad4, smad6, and smad7 with the exception that TGF-beta2 and smad3 were undetectable in JAR and JEG-3 cells. Immunoblot analysis confirmed the absence of smad3 protein in choriocarcinoma cells. Treatment with TGF-beta1 induced smad3 phosphorylation and smad3 translocation to the nucleus in the normal and premalignant trophoblast cells. These results suggest that loss of smad3 may account for a functional disruption in the TGF-beta signaling pathway in choriocarcinomas, but not in the premalignant trophoblast.

Genetic origin of malignant trophoblastic neoplasms analyzed by sequence tag site polymorphic markers

OBJECTIVE

To study the causative conception of malignant gestational trophoblastic neoplasms (GTNs), we analyzed malignant GTNs by microsatellite PCR markers.

METHOD

DNAs extracted from 12 malignant GTNs were subjected to PCR for five different chromosomal locations.

RESULT

Of the 7 cases after a complete mole (CM), 5 were derived from androgenesis, but the remaining 2 were from normal fertilization. Of the 5 cases after nonmolar pregnancies, 2 placental site trophoblastic tumors had alleles from both parents. Of the other 3 choriocarcinomas, 1 was from normal fertilization after spontaneous abortion but 2 originated from androgenesis, suggesting that 1 was from a CM prior to the antecedent abortion, transforming after a long interval.

CONCLUSION

By combining the previous cases with these, our analysis of 39 cases demonstrated that trophoblastic neoplasms can arise from at least three different modes of origin (androgenesis, normal fertilization, and parthenogenesis), and antecedent pregnancy is not always identical to the causative conception. Placental site trophoblastic tumors might have different machinery for carcinogenesis because of the predominance of paternal and maternal contributions. In addition, a long dormancy of trophoblasts before malignant transformation, especially for those originating from normal fertilization, was also suggested.

Altered mitochondrial gene expression in human gestational trophoblastic diseases

To assess the molecular basis of phenotypic alterations present in the gestational trophoblastic diseases (GTDs) and to identify genes whose expression is specifically associated with these placental proliferative disorders we performed differential display (DD) techniques. This strategy resulted in the isolation of four mitochondrial transcripts downregulated in benign, as well as in malignant, trophoblastic diseases encoding the cytochrome oxidase subunit I (COX I), the ATPase subunit 6, the 12S ribosomal RNA (12S rRNA) and the transfer RNA for phenylalanine (tRNA(Phe)). This expression pattern was confirmed by Northern blot in normal early placenta (NEP), complete hydatidiform mole (CHM), persistent gestational trophoblastic disease (PGTD) and the human choriocarcinoma derived cell line JEG-3. Quantification of mitochondrial DNA by dot blot indicated that these changes in expression were not associated with a significant alteration in the number of mitochondrial genome. In addition, a reduction in the mitochondrial transcription factor A (mtTFA) mRNA level was observed in benign as well as in malignant trophoblastic diseases in correlation with the decrease in the mitochondrial transcript levels. Furthermore, Western blot analysis for COX-I showed a close parallelism with the expression level of the cognate RNA. Taken together, these data demonstrate that a significant change in mitochondrial transcription is associated with the phenotypic alteration present in GTDs.

Gestational trophoblastic diseases: new standards for therapy

Gestational trophoblastic disease (GTD) is a spectrum of rare neoplastic conditions that are highly curable, even in the presence of widely metastatic disease. These diseases vary from partial hydatidiform mole, which rarely metastasizes and infrequently requires treatment with chemotherapy, to choriocarcinoma, for which multi-agent chemotherapy is the standard treatment. Much has been learned regarding the epidemiology of this disease, and our understanding of the genetics underlying GTD is rapidly expanding. As technology such as ultrasonography and sensitive tests for beta-human chorionic gonadotropin have evolved, the presentation of molar pregnancy has significantly changed, although the incidence of persistent GTD has not decreased. This review highlights these recent advancements in the epidemiology, genetics, diagnosis, and treatment of gestational trophoblastic disease.

Recent advances in gestational trophoblastic disease

Recent advances have increased our understanding of gestational trophoblastic disease, and epidemiologic studies have demonstrated that there are important differences in risk factors for complete and partial mole. Complete moles are now increasingly being diagnosed in the first trimester, affecting their clinical presentation and pathologic characteristics. While important advances have been made in chemotherapy, it is now recognized that etoposide is associated with a risk of second tumors. Several studies have advanced understanding of the molecular biology of gestational trophoblastic disease, and this is important for the eventual development of new and innovative therapy.

Pathogenesis of placental site trophoblastic tumor may require the presence of a paternally derived X chromosome

Placental site trophoblastic tumor (PSTT) is a neoplastic proliferation of intermediate trophoblasts that invades the myometrium at the placental site after a pregnancy. Less than 100 cases have been reported. Information of the sex assignment of the antecedent gestation is available in 21 cases: 18 of these were female. To explore this interesting phenomenon, we have determined the sex chromosome composition of the tumor tissue preserved in paraffin blocks for five new cases of this condition. The last documented gestational event included a normal vaginal delivery of female infants in three cases, normal vaginal delivery of an infant of unknown sex in one case and a molar gestation in one case. Using the X-linked human androgen receptor (AR) gene as a polymorphic marker, we showed that in all five cases the tumor had a likely XX chromosomal composition; and in four cases it was possible to determine that one of the X chromosomes was of paternal origin. In one case, the paternal X chromosome showed no polymorphism to either maternal X chromosomes. In addition, sensitive semi-nested PCR failed to show a human Y chromosome element in any of the five cases of PSTT. Overall, of 21 cases from the literature and 5 cases of ours, 89% (23 of 26) showed an XX genomic composition in PSTT, either by history or genetic analysis. These results suggest that most PSTT were derived from the antecedent female conceptus and were likely to have possessed a functional paternal X chromosome. Methylation status analysis at the AR locus was performed in the three PSTT in which the paternal X chromosome was identifiable. In two cases, the paternal AR locus was hypomethylated while the corresponding maternal locus was hypermethylated. The methylation status of other loci was not investigated. Collectively, sex chromosome analysis of five cases of PSTT with literature support suggests a unique genetic basis for the development of PSTT that involves the paternal X chromosome. Although largely speculative, an active paternal X chromosome may be of importance in the pathogenesis of PSTT.

Imprinted H19 gene expression in embryogenesis and human cancer: the oncofetal connection

Cancer cells resemble embryonal cells morphologically and share with them characteristics such as reduced differentiation, rapid proliferation rate, and increased motility. Genes expressed in embryogenesis, down-regulated with tissue maturation and reexpressed in cancer, are designated as oncofetal genes, and many of them are used as tumor markers. The H19 gene is an imprinted gene that is expressed from the maternal allele and functions as an RNA molecule. It is abundantly expressed in fetal life and down-regulated postnatally. We have shown oncofetal expression of H19 in human cancer. The study of H19 expression in testicular germ cell tumors of adolescents and young adults, which follow lines of differentiation of the conceptus, demonstrates dissociation between level of expression and monoallelic versus biallelic expression, which are two independent oncofetal characteristics of cancer. Expression of the maternally expressed H19 from the paternal allele in the villous cytotrophoblastic cells of the androgenetic complete hydatidiform mole is designated relaxation of imprinting. H19 is abundantly expressed in the fetal bladder mucosa and in carcinoma of the urinary bladder. It is a marker of early recurrence and may be used as a potential basis for gene therapy.

Trophoblastic cells expressing human chorionic gonadotropin genes in peripheral blood of patients with trophoblastic disease

We attempted to identify the cells expressing alpha and beta subunits of human chorionic gonadotropin (hCG) in the peripheral blood of patients with trophoblastic disease and normal pregnant women by using reverse transcriptase polymerase chain reaction (RT-PCR) and Southern blot. By this method, the mRNAs of hCG alpha and hCG beta were detected in the peripheral blood mononulear cells (PBMNC) from 3 of 7 hydatidiform mole (mole) and 1 of 4 choriocarcinoma patients as well as from normal pregnant women during the first trimester. None of the mRNAs of hCG subunits was detected in the PBMNC from healthy male and nonpregnant healthy women examined. The expression of hCG alpha and hCG beta in patients with trophoblastic disease and normal pregnant women almost correlated with their plasma levels of intact hCG. The present study indicates that the cells expressing hCG alpha and hCG beta, which virtually represent trophoblasts, are circulating in the peripheral blood of patients with trophoblastic disease as well as of normal pregnant women.

Recent advances in gestational trophoblastic disease

Advances in the last 20 years have led to a better understanding of the process of gestational trophoblastic disease (GTD), and consequently, to improved diagnosis, management, and prognosis. Patients with GTD should be registered at a trophoblastic disease center for follow-up, and those with persistent disease should receive chemotherapy, methotrexate, and folinic acid for low-risk disease, and EMACO (etoposide, actinomycin-D, methotrexate, vincristine, and cyclophosphamide) for high-risk disease, without loss of fertility. Most patients with relapsing or resistant disease can be treated effectively with surgery and/or cisplatin in EP/EMA (etoposide, platinum-etoposide, methotrexate, actinomycin-D) combination.

Studies of non-disjunction in trisomies 2, 7, 15, and 22: does the parental origin of trisomy influence placental morphology?

Recently, there have been several molecular studies of trisomic fetuses and liveborns which have examined the parent and meiotic stage of origin of nondisjunction. However, little is known about the possible phenotypic effects of the origin of trisomy. For trisomic spontaneous abortions, no distinct phenotype has been described, although some have been reported to have features, such as trophoblastic hyperplasia, similar to hydatidiform moles. In the present report, we describe molecular and histological studies of spontaneous abortions with trisomies 2, 7, 15, or 22, conditions occasionally linked to trophoblastic hyperplasia. Our results provide strong evidence for chromosome specific mechanisms of nondisjunction, with trisomy 2 having a high frequency of paternally derived cases and trisomy 7 typically originating postzygotically. In studies correlating parental origin of trisomy with phenotype, we found no difference in the proportion of cases with trophoblastic hyperplasia, fetal tissue, nucleated red blood cells, or hydropic villi among paternally or maternally derived trisomies 2, 7, 15, or 22. However, paternally derived trisomies tended to abort earlier than maternally derived trisomies. This suggests that parental origin might affect the developmental stage at which abortion occurs but not other features of placental phenotype.

DOC-2/hDab2, a candidate tumor suppressor gene involved in the development of gestational trophoblastic diseases

Gestational trophoblastic diseases comprise a spectrum of interrelated diseases including partial mole, complete mole and gestational choriocarcinoma. Using reverse transcriptase PCR (RT-PCR) analysis, we identified higher levels of DOC-2/hDab2 expression in the normal trophoblast cells in culture than in choriocarcinoma cell lines. Subsequent study using immunohistochemistry showed high levels of DOC-2/hDab2 protein expression in normal trophoblast tissues but significantly lower levels of expression in gestational trophoblastic disease tissues, particularly in complete mole and choriocarcinoma. When DOC-2/hDab2 was transfected into the choriocarcinoma cell lines, Jar, JEG and BeWo, the stable transfectants showed significantly reduced growth rate in culture. These data suggest that down regulation of DOC-2/hDab2 may play an important role in the development of gestational trophoblastic diseases.

Prevalence of the partial molar phenotype in triploidy of maternal and paternal origin

Triploid partial moles are at risk for trophoblastic neoplasia, yet the prevalence, parent of origin, and evolution of the partial molar phenotype amongst all triploids remains controversial. We determined parental origin by polymerase chain reaction (PCR) analysis, stage of development by gross and histological criteria, and partial molar status according to strict diagnostic criteria for all triploids identified amongst 1,054 consecutively karyotyped spontaneous abortions. Triploidy was detected in 64 of 832 successfully karyotyped specimens. Complete data were collected in 59 cases. Diandric origin was found in 39 specimens, and 20 of these fulfilled all four criteria for partial mole (trophoblast hyperplasia, dimorphic population of large and small villi, villous hydrops greater than 0.5 mm, and irregular villous contour). We separated the 19 diandric triploids not fulfilling all criteria for partial mole into four groups: specimens of early developmental stage, which we believed represented developing ("early") partial moles (n = 3), cases of late developmental stage, which we believed represented involuting ("ancient") partial moles (n = 4), cases showing some but not all criteria for partial mole (n = 7), and specimens with few if any criteria suggestive of partial mole (n = 5). In triploids of digynic origin (n = 20), developmental stage was significantly lower, fetal tissue was more frequently identified, and all specimens showed well-preserved fetal red blood cells. Digynic triploids occasionally showed irregular contour, dimorphic villi, and a mild form of trophoblast hyperplasia but never showed hydropic degeneration and were never suspicious for partial mole.

New concepts in trophoblastic growth and differentiation with practical application for the diagnosis of gestational trophoblastic disease

Human trophoblast in normal implantation and placentation appears to undergo two different pathways of differentiation resulting in the development of villous and extravillous trophoblast. Cytotrophoblast (CT) differentiates abruptly into syncytiotrophoblast (ST) on the villous surface as compared with the spectrum of differentiation exhibited by extravillous trophoblast where CT differentiates into intermediate trophoblast (IT) and then into multinucleated intermediate trophoblastic cells (MITC). The various types of gestational trophoblastic lesions can be defined and related to discrete pathologic aberrations occurring at different stages of trophoblastic differentiation. The rapid advance in the discovery of new trophoblastic markers has facilitated the molecular dissection of the lineage and differentiation stages of trophoblast and related these to various trophoblastic lesions. Furthermore, antibodies against these markers, especially those that are able to recognize formalin-resistant epitopes, have considerable value in the study and differential diagnosis of different types of gestational trophoblastic disease.

Gestational trophoblastic disease. Molecular and genetic studies

For a geneticist, the gestational trophoblastic diseases are a particularly interesting group of diseases. Hydatidiform moles were one of the first of a growing number of human disorders shown to result from the phenomenon of genomic imprinting, while gestational trophoblastic tumors are unusual neoplasms in that they derive not from the patients' own tissue but from a genetically distinct pregnancy. We review here the development of our understanding of the genetics of gestational trophoblastic disease and describe how modern molecular genetic techniques can be used to aid in the management of these conditions and further our understanding of their unusual biology.

A subset of gestational trophoblastic disease characterized by abnormal chromosome 8 copy number detected by fluorescence in situ hybridization

The present paper describes the results of research conducted to ascertain whether the report by Mark et al. [1], describing the concurrence of congenital trisomy 8 mosaicism and gestational trophoblastic disease (GTD) in a 42 year-old Gravida IV, Para IV patient was an isolated event. In contrast to other cases described in the literature, the patient described in Mark et al. [1] had no additional confounding chromosomal abnormalities other than trisomy 8. To the best of our knowledge, ours was the only reported case of constitutional trisomy 8 mosaicism associated with gestational trophoblastic disease, a rare gynecological disease entity. The question arises whether there exists a subset of patients with GTD characterized by an abnormal chromosome 8 copy number. The implicit hypothesis is that an abnormal number of chromosome 8 somehow predisposes to cancer. A pilot study of 10 cases of GTD was conducted using fluorescence in situ hybridization (FISH) and a commercial chromosome 8-specific alpha-satellite probe on formalin-fixed, paraffin-embedded patient tissues. Among eight informative cases successfully completed, two cases (25%) were found to be trisomic, when a cut-off point of 10% trisomic cells is adopted. Another two cases (25%) were found to be triploid. The results of our FISH study indicated that an abnormal chromosome 8 copy number found in Mark et al. [1] is unlikely to be an isolated event. Our data are consistent with the hypothesis that a subset of GTD indeed may exist which is characterized by more than two copies of chromosome 8. The present findings corroborate those recently found in breast, prostate, and other cancers.

Genetic aspects of gestational trophoblastic diseases: a general overview with emphasis on new approaches in determining genetic composition

All gestational trophoblastic tumors are derived from a fertilization event. In the hydatidiform moles, varying degrees of excess paternal DNA lead to varying histopathologic forms of these tumors. The placental site trophoblastic tumors and the choriocarcinomas may follow normal pregnancy, abortions and hydatidiform moles, and, thus evince a wide range of genetic compositions reflecting their gestation of origin. Advances in molecular biological diagnoses now allow for the determination of the gestational or non-gestational origin of trophoblastic tumors, and, may well provide fantastic new insights into the biology of these unusual tumors.

C-erbB-2 amplification and expression in gestational trophoblastic disease correlates with DNA content and karyotype

The subject of this retrospective study was to evaluate the potential benefit of the c-erbB-2 oncogene amplification and expression in 27 complete hydatidiform moles as well as in 9 cases of persistent gestational trophoblastic disease defined by elevated serum beta-human choriongonadotropin. The persistent cases were histopathologically classified as 5 complete hydatidiform moles, 3 invasive moles and 1 choriocarcinoma. In addition, we determined the DNA content and the karyotype of the sex chromosomes. The data were correlated with the histopathologic characteristics of gestational trophoblastic diseases. Cases with c-erbB-2 amplification and expression in combination with DNA hyperploidy showed higher proliferation and a more aggressive behavior (2 complete hydatidiform moles with lung and liver metastases, 2 invasive moles and 1 choriocarcinoma). XY karyotype was evident in the choriocarcinoma and in two complete hydatidiform moles with advanced stage and DNA hyperploidy.

Human chorionic gonadotrophin-beta gene sequences in women with disorders of HCG production

Women with recurrent abortion, primary unexplained infertility, and gestational trophoblastic neoplasia (GTN) manifest disordered human chorionic gonadotrophin (HCG) secretion. Mutations in the HCG beta/luteinizing hormone (LH) beta gene complex could cause aberrant HCG production in these disorders. The purpose of this study was to determine whether HCG beta gene deletions occur in women with recurrent abortion or primary unexplained infertility, and whether HCG beta gene duplications are present in women with GTN. DNA was extracted from 10 patients with unexplained recurrent abortion, 10 patients with unexplained primary infertility, 12 patients with GTN, three partners of women with GTN, and 30 controls. Southern blots were constructed and hybridized with DNA probes for HCG beta-5 and the LH beta gene. No gene deletions were identified in patients with recurrent abortion or primary unexplained infertility. Likewise, no gene duplications were identified in women with GTN. A previously described Mbol restriction fragment length polymorphism (RFLP) was identified in both patients and controls. A new Pstl RFLP was also characterized, but was present in patients and controls. Deletion/duplication mutations in the HCG beta/LH beta gene complex do not appear to be common causes of aberrant HCG production in humans with these disorders.

Intracytoplasmic sperm injection combined with preimplantation genetic diagnosis for the prevention of recurrent gestational trophoblastic disease

A strategy for the prevention of repeated molar pregnancies by using intracytoplasmic sperm injection (ICSI) coupled with preimplantation genetic diagnosis (PGD) with fluorescence in-situ hybridization (FISH) was developed. In this approach, complete moles which arise from dispermic fertilization are avoided by the use of ICSI. ICSI is followed by preimplantation selection against the transfer of 46,XX embryos, thus preventing complete moles resulting from a fertilization of an inactive oocyte, by a haploid X-bearing spermatozoon which subsequently duplicates. Triploid partial moles which arise mainly from dispermic fertilization may also be prevented by ICSI. The preimplantation confirmation of diploidy by FISH guards against triploid partial moles which may result from mechanisms other than dispermic fertilization. The employment of this strategy in an attempt to prevent a repeated event of molar pregnancy in a patient with a history of two previous episodes of gestational trophoblastic disease is reported.

Gestational trophoblastic disease following the evacuation of partial hydatidiform mole: a review of 66 cases

OBJECTIVE

The current study was undertaken in order to identify the clinical characteristics and natural history, as well as methods of investigation and available therapy, of persistent gestational trophoblastic disease (GTD) following the evacuation of partial hydatidiform mole (PM).

METHODS

Case reports of persistent GTD following the evacuation of partial mole, were searched using the Medline computerized retrieval system. There were 66 such cases (including 4 cases treated at our department), representing 2.9% of GTD following PM.

RESULTS

The mean age of the women at diagnosis was 28.4 years and mean gravidity was 2.99. The mean gestational age at diagnosis was 15.5 weeks and the mean uterine size was 13.6 weeks. The most common presenting symptom was vaginal bleeding. In the majority of the patients, the pre-evacuation diagnosis was incomplete or missed abortion.

CONCLUSIONS

Although the malignant potential of PM is low, persistent GTD may develop after PM and may even metastasize, it is usually responsive to single agent chemotherapy but may require combination chemotherapy. Therefore, after evacuation of PM, these women should be followed with serial serum b-hCG. Further research is needed to enable earlier identification of PM that eventually will develop persistent GTD.

Gestational trophoblastic disease

GTD occurs in fewer than 1 in 1200 pregnancies in the United States, but it is much more common in Asia and Latin America, where its incidence may be as high as 1 in 200 pregnancies. Risk factors for GTD include advanced or young maternal age, low socioeconomic status, and prior hydatidiform mole. Early diagnosis and prompt treatment are key to a favorable outcome, and thus recognition of the signs and symptoms of the disease is important for all physicians. Because these diseases have low incidences and occur after reproductive events, screening for them in the general population is not worthwhile. No chemopreventive agents have yet been studied in women at risk for GTD, but the oral contraceptive is a good candidate.

Placental site trophoblastic tumor: molecular analysis and clinical experience

Placental site trophoblastic tumor is a very rare variant of gestational trophoblastic disease which differs histologically and immunocytochemically from gestational choriocarcinoma. The English language literature includes only 74 reported cases. Seventeen patients have been managed at Charing Cross Hospital with this diagnosis. The median follow-up is 4.6 years, and the 5-year overall survival is 80% (95% confidence interval, 55-93%). Multivariate regression analysis identified an interval of >2 years since the preceding pregnancy as an independent adverse prognostic factor. Genotypic analysis by PCR allelotyping has confirmed the gestational origin of all 11 tumors successfully studied. More detailed molecular analysis has identified the causative pregnancy for eight tumors. Five were diploid biparental tumors following term pregnancies, and three were androgenetic tumors following monospermic complete hydatidiform moles.

Malignant trophoblastic neoplasms with different modes of origin

The genetic origin of 24 trophoblastic neoplasms was determined using PCR polymorphisms. Based on pregnancy history, these tumors included nine postmolar trophoblastic tumors, 12 tumors preceded by live birth or abortion, and three nongestational tumors. Androgenetic origin was defined in eight post-molar trophoblastic tumors, and the remaining one might have arisen from a normal fertilization. Six tumors retained genetic features carried by the homozygous complete mole. Two tumors showed PCR polymorphism compatible with that of the heterozygous complete mole. All 12 tumors in the second class had alleles of both paternal and maternal contribution. However, discordance of sex between the antecedent pregnancy product and the tumor was recognized in three choriocarcinomas. The absence of paternal contribution suggested a parthenogenetic origin of three nongestational choriocarcinomas. The findings that PCR polymorphisms were either homozygous in certain loci or heterozygous in others may mean that the tumor was derived from a germ cell after meiosis I. As a result, at least three subtypes with different modes of origin were demonstrated in the 24 trophoblastic tumors. These findings underscore the importance of precise genetic marker analyses in a large series to clearly identify clinical and biologic characteristics of each subset of tumors.

Gestational trophoblastic diseases: current trends and perspectives

Gestational trophoblastic diseases (GTD) include a spectrum of diseases from the potentially premalignant hydatidiform mole to the highly aggressive choriocarcinoma. Most complete moles have diploid chromosomes, nearly always of pure paternal origin, whereas most partial moles have triploid chromosomes, containing one haploid maternal set and two paternal sets. The first-line treatment of molar pregnancies is suction evacuation. In patients with persistent trophoblastic diseases or choriocarcinoma, single agent or multiagent chemotherapy is indicated, depending on the prognostic score of the individual patient. With careful follow-up and appropriate treatment, nearly all patients with gestational trophoblastic diseases can be cured. Although many advances have been made in the cytogenetics, molecular biology and immunobiology of GTD, the reasons for its unique curability remain unclear. Studies comparing induction of apoptosis and multidrug resistance gene expression, in normal trophoblasts and GTD, may elucidate the mechanism behind the good response of GTD to chemotherapy. This may give some innovative insight into chemoresistance.

Fluorescent in situ hybridization assessment of chromosome copy number in gestational trophoblastic disease

The concurrence of congenital trisomy 8 mosaicism and gestational trophoblastic disease in a forty-two-year-old Gravida IV, Para IV female has been described. In contrast to other cases in the literature, this patient had no additional confounding chromosomal abnormalities other than trisomy 8. To the best of our knowledge, this was the only reported case of constitutional trisomy 8 mosaicism associated with gestational trophoblastic disease, a rare gynecological disease entity in and by itself. The present report describes fluorescent in situ hybridization (FISH) studies for assessing chromosome 8 copy number on various patient tissues. The results of the FISH studies are compared with each other and with the original cytogenetic studies. It is concluded that the overall frequency of trisomy 8 cells is lower in the FISH studies using archival material than in the original conventional cytogenetic studies. This is true for the uterus and lung tissues with a metastatic tumor. The possible reasons for the somewhat different frequencies found between conventional cytogenetics via GTG-banding and interphase cytogenetics via FISH are discussed.

Ploidy analysis by flow cytometry and fluorescence in situ hybridization in hydropic placentas and gestational trophoblastic disease

Placentas with hydropic change may be hydropic degeneration (HD) or gestational trophoblastic disease (GTD), partial (PM) or complete (CM) hydatidiform mole. The separation of HD from PM and PM from CM by histological findings may be problematic in some cases and can be clarified with ploidy analysis. Fluorescence in situ hybridization (FISH) using a probe to chromosome 7 (D7Z1) was applied to tissue cut from paraffin blocks from 10 histologically representative cases each of HD, PM, and CM on which ploidy had been previously confirmed by flow cytometry from paraffin embedded tissue. Villous stromal cells and nonproliferative trophoblast were examined for number of signals/cell and percentage of cells/placenta with three hybridization signals. The mean number of hybridization signals/cell was HD 1.14; PM 1.79; and CM 1.17, with statistical significance between HD and PM (P < .0001), and PM and CM (P < .0001). The mean percentage of cells/placenta with three hybridization signals was HD 1.10%, PM 23.1%, and CM 2.11%, with statistical significance between HD and PM (P < .0001), and PM and CM (P < .0001). In addition, there was no overlap in the mean percentage of cells with three hybridization signals between HD and PM, and PM and CM. Chromosome 2 probe (D2Z1) was applied to tissues that had three chromosome 7 signals to exclude trisomy, and in all cases three signals were present confirming triploidy in PM. FISH can identify diploid and triploid hydropic placentas in paraffin-embedded tissue to assist in differentiating HD from PM, and PM from CM.

p53 expression in gestational trophoblastic disease

The p53 expression of normal trophoblasts (11 cases), partial moles (11 cases), complete moles (19 cases), and gestational choriocarcinoma (eight cases) were studied. We found that p53 is frequently expressed in gestational choriocarcinoma and in hydatidiform moles (mainly cytotrophoblasts), whereas syncytiotrophoblasts are generally spared. This finding supports the view that p53 expression is a reflection of proliferative capacity of cells rather than an indicator of neoplastic or malignant transformation. The greater p53 expression observed in complete moles as compared with partial moles is in keeping with the more pronounced trophoblastic hyperplasia and proliferative activity of complete moles. More interesting was the observation that p53 expression was also noted in normal trophoblasts, secretory endometrial glands, and decidual cells of the stroma. Therefore, it appears that the immunohistochemical expression of p53 can occur in a variety of situations, including neoplastic, proliferative, and nonproliferative conditions. Although p53 mutations are often the basis of excessive accumulation of mutant p53 protein in malignancies, other mechanisms may be involved in nonneoplastic conditions. These findings emphasize the need for caution in the interpretation of immunohistochemical expression of p53 protein.

Constitutional trisomy 8 mosaicism and gestational trophoblastic disease

Concurrence of congenital trisomy 8 mosaicism and gestational trophoblastic disease in a 42-year-old gravida IV, para IV female is described in the present report. In contrast to other cases described in the literature, our patient had no known additional confounding chromosomal abnormalities other than trisomy 8. The finding of trisomy 8 mosaicism in yet another type of cancer provides further support for the hypothesis of an increased predisposition to cancer in tissues with constitutional genomic imbalance, which can manifest itself as numerical chromosomal abnormalities (e.g., trisomies) or structural chromosomal abnormalities (e.g., translocations). To the best of our knowledge, this is the only report in the English literature of constitutional trisomy 8 mosaicism associated with gestational trophoblastic disease, a rare gynecologic disease entity in itself.

Paternally derived H19 is differentially expressed in malignant and nonmalignant trophoblast

The paternal allele of the H19 gene has been shown to be transcriptionally inactive in the developing human embryo. Using reverse transcription PCR and RNase protection assays, we demonstrate that expression of H19 is predominantly, but not exclusively, from the maternal allele in the human placenta. In situ hybridization analysis shows strong expression of the H19 gene in eight complete hydatidiform moles, hyperplastic tissues consisting of trophoblasts which contain only paternally derived genetic material, indicating that H19 is not functionally imprinted in this tissue. H19, a putative growth suppressor, is oppositely imprinted to the neighboring insulin-like growth factor II (IGF2) gene and an up-regulation of IGF2 expression has been linked previously to a down-regulation of H19 expression in the progression to Wilms' tumor. Two cases of complete hydatidiform mole which progressed to choriocarcinoma show high levels of expression of both H19 and IGF2. The choriocarcinomas which developed from these complete hydatidiform moles showed similar expression of IGF2 but a decreased number of H19-positive cells, which may reflect selection for cells expressing IGF2 and against those expressing H19 in this tissue.