Insights into cAMP-dependent molecular mechanisms regulating expression and function of LGALS16 gene in choriocarcinoma JEG-3 cells

The human choriocarcinoma cell line JEG-3 offers a valuable model to study galectin-16 gene (LGALS16) expression and functions in the context of placental cell differentiation and cancer cell biology. Recent evidence indicates that cAMP-mediated signaling pathways might be responsible for the upregulation of LGALS16; however, the underlying mechanisms are unknown. Here, we employed biochemical inhibitors of the cAMP cascade and CRISPR/Cas9 engineered cells to assess regulatory patterns and associations between cAMP-induced trophoblast differentiation and LGALS16 expression in JEG-3 cells. The expression of LGALS16 was significantly upregulated in parallel with human chorionic gonadotropin beta (CGB), a biomarker of syncytiotrophoblast differentiation, in response to 8-Br-cAMP. Inhibition of p38 MAPK and EPAC significantly altered LGALS16 expression during differentiation, while PKA inhibition failed to change LGALS16 and CGB3/5 expression in our cell model. The CRISPR/Cas9 LGALS16 knockout cell pool expressed a significantly lower amount of CGB3/5, a reduced level of CGB protein, and an unaltered cell growth rate in response to 8-Br-cAMP in comparison with wild-type JEG-3 cells. Collectively, these findings suggest that LGALS16 is required for the trophoblast-like differentiation of JEG-3 cells, and its expression is mediated through p38 MAPK and EPAC signaling pathway branches.

Short tandem repeats genotyping of gestational choriocarcinoma - our experiences

OBJECTIVE

This short communication demonstrates how short tandem repeat genotyping can identify the origin of gestational choriocarcinoma.

MATERIALS AND METHODS

The origin of gestational choriocarcinoma in our three cases was determined using the short tandem repeats genotyping technique, which involved quantitative fluorescent PCR and fragmentation analysis.

RESULTS

In Case 1 despite no medical history of molar pregnancy, DNA analysis indicated that the choriocarcinoma originated from a homozygous complete hydatidiform mole. We conclude, that the patient's complete abortion 10 years prior to the choriocarcinoma diagnosis was an undiagnosed complete hydatidiform mole. In Case 2 and Case 3 the clinically presumed origin of choriocarcinoma was confirmed.

CONCLUSION

Determining the origin of choriocarcinoma is essential for clinical application, as it affects the FIGO scoring system for gestational trophoblastic neoplasia, which determines the patient's prognosis and treatment approach.

Molecular Evidence for Epithelial Origin of Mixed Ovarian Epithelial-Germ Cell Neoplasms: Report of 2 Cases and Review of Literature

Ovarian germ cell tumors (GCT) account for 2% to 3% of malignant ovarian neoplasms in Western countries and typically occur within the first 2 decades. When presenting later in life, GCTs may be associated with epithelial malignancies. In these circumstances, it has been theorized that these tumors may originate from a somatic, rather than germ cell origin, especially in the postmenopausal setting; however, the true derivation is not fully understood. Our database was searched for primary ovarian GCTs associated with a malignant epithelial component in patients above 35 yr of age, from 2006 to 2021. Two cases were identified and in each case, slides were reviewed and targeted next-generation sequencing was utilized to identify and compare gene mutation variants in morphologically distinct components. Patient A is a 58-yr-old, with choriocarcinoma and minor component of mucinous adenocarcinoma, and patient B is a 43-yr-old, with yolk sac tumor and minor component of endometrioid adenocarcinoma. The morphologically distinct areas in each case showed disparate staining patterns; however, next-generation sequencing demonstrated identical mutation variants within both the germ cell and epithelial components. Variants in CDKN2A , PIK3CA , PIK3R1 , and TP53 were present in patient A's tumor, while patient B's tumor showed CTNNB1 , PIK3R1 , and 2 PTEN variants. These mutational patterns are similar to those seen in pure epithelial counterparts, suggesting somatic derivation of the germ cell component. These rare tumors portend a poor prognosis and understanding their origin has clinical and therapeutic implications.

NLRP7 Enhances Choriocarcinoma Cell Survival and Camouflage in an Inflammasome Independent Pathway

Background: Gestational choriocarcinoma (GC) is a highly malignant trophoblastic tumor that often develops from a complete hydatidiform mole (HM). NLRP7 is the major gene responsible for recurrent HM and is involved in the innate immune response, inflammation and apoptosis. NLRP7 can function in an inflammasome-dependent or -independent pathway. Recently, we have demonstrated that NLRP7 is highly expressed in GC tumor cells and contributes to their tumorigenesis. However, the underlying mechanisms are still unknown. Here, we investigated the mechanism by which NLRP7 controls these processes in malignant (JEG-3) and non-tumor (HTR8/SVneo) trophoblastic cells. Cell survival, dedifferentiation, camouflage, and aggressiveness were compared between normal JEG-3 cells or knockdown for NLRP7, JEG-3 Sh NLRP7. In addition, HTR8/SVneo cells overexpressing NLRP7 were used to determine the impact of NLRP7 overexpression on non-tumor cells. NLRP7 involvement in tumor cell growth and tolerance was further characterized in vivo using the metastatic mouse model of GC. Results: We demonstrate that NLRP7 (i) functions in an inflammasome-dependent and -independent manners in HTR8/SVneo and JEG-3 cells, respectively; (ii) differentially regulates the activity of NF-κB in tumor and non-tumor cells; (iii) increases malignant cell survival, dedifferentiation, and camouflage; and (iv) facilitates tumor cells colonization of the lungs in the preclinical model of GC. Conclusions: This study demonstrates for the first time the mechanism by which NLRP7, independently of its inflammasome machinery, contributes to GC growth and tumorigenesis. The clinical relevance of NLRP7 in this rare cancer highlights its potential therapeutic promise as a molecular target to treat resistant GC patients.

Ultra-High-Risk Gestational Choriocarcinoma of the Ovary Associated with Ectopic Pregnancy

Gestational choriocarcinoma of the ovary is an exceptionally rare and highly aggressive tumor. Preoperative diagnosis of extrauterine choriocarcinoma is difficult due to nonspecific clinical presentation and its resemblance to ectopic pregnancy. Without molecular genetic analysis, it is not possible to reliably differentiate gestational from non-gestational choriocarcinoma. Here, we present a case of a 44-year-old woman who presented to our emergency department with complaints of pelvic pain, vaginal bleeding, and amenorrhea. Because of a recent history of conservatively managed ectopic pregnancy, the patient underwent emergency laparoscopy. Right-sided salpingo-oophorectomy was performed due to intraoperatively suspected ovarian ectopic pregnancy. Histopathology results revealed the diagnosis of ovarian choriocarcinoma of possible gestational origin. It was classified as FIGO stage IV and WHO ultra-high-risk, and she underwent multi-agent chemotherapy without major complications. She has remained in complete remission after a 12-month follow-up. Considering the rarity of this diagnosis, we conducted a literature review including all published cases of suspected gestational choriocarcinomas of the ovary. We conclude that due to the rarity of this entity, preoperative differentiating between ovarian ectopic pregnancy and ovarian choriocarcinoma is extremely challenging, and without molecular genetic analysis, it is not possible to identify the genetic origin of the tumor.

LRSAM1 E3 Ubiquitin Ligase Promotes Choriocarcinoma Progression and Metastasis via p53/p21 Signaling Impediment

Objective

The E3 ubiquitin ligase LRSAM1 (LRSAM1) was involved in many cancers, but whether it exerts anti- or protumor efficacies on choriocarcinoma cellular structures remains unknown. We wanted to explore the efficacies of aberrant LRSAM1 expression on human choriocarcinoma cellular structures and the underlying mechanisms.

Methods

LRSAM1 mRNA expressions in choriocarcinoma lines of cells JEG-3 and JAR cellular structures, as well as HTR8/sev8 human trophoblastic cell line cellular structures, were assessed using assay analysis of quantitative real-time polymerase chain reactions. We compared cell proliferation, migratory flow, invasive force, adhesion, and apoptotic process between cellular structures infected with si-LRSAM1 plasmids versus negative controls using CCK-8, clone formation, Transwell, adhesion, and flow cytometry assays. Protein expressions of LRSAM1, E-cadherin, and N-cadherin (indicators of epithelial-mesenchymal transformation) and p53/p21 pathway components were quantitated using a Western blot assay. The morphology of tumor lesions was observed in xenografted nude mice using immunohistochemistry (IHC) analyses.

Results

LRSAM1 was markedly overexpressed within JEG-3 and JAR choriocarcinoma cellular structures compared to HTR8/sev8 trophoblast cellular structures. Compared to si-NC, LRSAM1 knockdown robustly restricted cell proliferating, migratory flow, invasive force, and adhesion and fueled apoptotic cell process in JEG-3 as well as JAR cellular structures and suppressed tumor growth, as evidenced by the reduction in tumor volume and weight in naked mice inoculated with transfected cellular structures. Compared to si-negative control (si-NC), si-LRSAM1 significantly decreased Ki67 (a proliferating indicator) and N-cadherin expressions but reduced E-cadherin expression in JEG-3 and JAR cellular structures. Blocking the p53/p21 pathway by pifithrin-a (a p53 restrictor) successfully reversed the anti-inhibitory effect of LRSAM1 depletion, resulting in enhanced proliferating and metastasis in JEG-3 and JAR cellular structures.

Conclusion

LRSAM1 exerts tumorigenic roles in choriocarcinoma. Via the activating of the p53/p21 pathway of signaling and impediment of choriocarcinoma cell proliferating, migratory flow, and invasive force, LRSAM1 knockdown slows the course of the disease. For choriocarcinoma diagnosis and treatment, it serves as a new therapeutic target.

CBR3-AS1 Accelerates the Malignant Proliferation of Gestational Choriocarcinoma Cells by Stabilizing SETD4

Background

Gestational choriocarcinoma (GC) is a rare malignant gestational trophoblastic tumor. Long noncoding RNA (lncRNA) CBR3 antisense RNA 1 (CBR3-AS1) has been reported to serve as a critical oncogene and facilitate tumor progression. Besides, we found that CBR3-AS1 is implicated in GC progression.

Materials and Methods

Gene and protein expression was detected via quantitative reverse transcription PCR (RT-qPCR) and western blot analyses, respectively. CCK-8 assay and colony formation assay were performed to assess cell proliferative abilities while flow cytometry analysis was applied for cell cycle and apoptosis. To analyze the specific mechanism among CBR3-AS1, SET domain containing 4 (SETD4), and polypyrimidine tract binding protein 1 (PTBP1), RNA binding protein immunoprecipitation (RIP), RNA pulldown, and mRNA stability assays were conducted.

Results

CBR3-AS1 was markedly upregulated in GC cells, and its downregulation suppressed cell proliferation, induced cell cycle arrest, but promoted cell apoptosis in GC. SETD4 was determined as the downstream mRNA of CBR3-AS1 and positively regulated by CBR3-AS1 in GC cells. Furthermore, CBR3-AS1 could interact with its RNA binding protein (RBP) PTBP1, thereby stabilizing SETD4 mRNA. Rescue assays verified that CBR3-AS1 facilitates GC cell malignant proliferation via SETD4.

Conclusion

CBR3-AS1 accelerates the malignant proliferation of GC cells via stabilizing SETD4.

ZBED1 Regulates Genes Important for Multiple Biological Processes of the Placenta

The transcription factor ZBED1 is highly expressed in trophoblast cells, but its functions in the processes of trophoblast and placental biology remain elusive. Here, we characterized the role of ZBED1 in trophoblast cell differentiation using an in vitro BeWo cell model. We demonstrate that ZBED1 is enhanced in its expression early after forskolin-induced differentiation of BeWo cells and regulates many of the genes that are differentially expressed as an effect of forskolin treatment. Specifically, genes encoding markers for the differentiation of cytotrophoblast into syncytiotrophoblast and factors essential for trophoblast cell fusion and invasion were negatively regulated by ZBED1, indicating that ZBED1 might be important for maintaining a steady pool of cytotrophoblast cells. In addition, ZBED1 affected genes involved in the regulation of trophoblast cell survival and apoptosis, in agreement with the observed increase in apoptosis upon knockdown of ZBED1 in forskolin-treated BeWo cells. In addition, genes implicated in the differentiation, recruitment, and function of innate immune cells by the placenta were affected by ZBED1, further suggesting a role for this protein in the regulation of maternal immune tolerance. In conclusion, our study implicates ZBED1 in major biological processes of placental biology.

miR-497-5p/SALL4 axis promotes stemness phenotype of choriocarcinoma and forms a feedback loop with DNMT-mediated epigenetic regulation

Choriocarcinoma stem-like cells (CSLCs) might be at the origin of choriocarcinoma development associated with drug resistance or relapse. Spalt-like transcription factor 4 (SALL4), which is considered to be a stemness-related gene, can be regulated by miRNAs. In this study, SALL4 result is associated with progression-free survival of choriocarcinoma patients and CSLC's stemness characteristics. In addition, it could be downregulated by miR-497-5p by direct binding. miR-497-5p silencing by hypermethylation promoted malignant CSLC phenotype in vitro and in vivo. Furthermore, increased DNA methyltransferases (DNMTs) by SALL4 upregulation inhibited miR-497-5p expression via hypermethylation promotion. SALL4 appeared to be a key factor in promoting stemness phenotype of choriocarcinoma. Silencing miR-497-5p and SALL4 promotes choriocarcinoma progression and forms a feedback loop with DNMT-mediated epigenetic regulation, playing a crucial role in stemness maintenance in choriocarcinoma.

An Overview of the Role of Long Non-Coding RNAs in Human Choriocarcinoma

Choriocarcinoma (CC), a subtype of trophoblastic disease, is a rare and highly aggressive neoplasm. There are two main CC subtypes: gestational and non-gestational, (so called when it develops as a component of a germ cell tumor or is related to a somatic mutation of a poorly differentiated carcinoma), each with very diverse biological activity. A therapeutic approach is highly effective in patients with early-stage CC. The advanced stage of the disease also has a good prognosis with around 95% of patients cured following chemotherapy. However, advancements in diagnosis and treatment are always needed to improve outcomes for patients with CC. Long non-coding (lnc) RNAs are non-coding transcripts that are longer than 200 nucleotides. LncRNAs can act as oncogenes or tumor suppressor genes. Deregulation of their expression has a key role in tumor development, angiogenesis, differentiation, migration, apoptosis, and proliferation. Furthermore, detection of cancer-associated lncRNAs in body fluids, such as blood, saliva, and urine of cancer patients, is emerging as a novel method for cancer diagnosis. Although there is evidence for the potential role of lncRNAs in a number of cancers of the female genital tract, their role in CC is poorly understood. This review summarizes the current knowledge of lncRNAs in gestational CC and how this may be applied to future therapeutic strategies in the treatment of this rare cancer.

Transcriptomic and immunohistochemical approaches identify HLA-G as a predictive biomarker of gestational choriocarcinoma resistance to monochemotherapy

OBJECTIVE

Using a transcriptional approach on tissue samples, we sought to identify predictive biomarkers of post molar malignant transformation, and of choriocarcinoma chemosensitivity to mono- (methotrexate or actinomycin D) or polychemotherapy [EMA(Etoposide, Methotrexate, Actinomycin D)-CO(Cyclophosphamide, Vincristine) and EMA-EP(Etoposide, Cisplatine)] regimens.

METHODS

We studied the expression of a 760-gene panel (PanCancer Pathway) related to oncogenesis and immune tolerance in tissue samples of complete hydatidiform moles and gestational choriocarcinoma.

RESULTS

We did not identify any differentially expressed gene between moles with post molar malignant transformation in choriocarcinoma (n = 14) and moles with remission (n = 20). In monochemoresistant choriocarcinoma (n = 34), four genes (HLA-G, COL27A1, IL1R2 and GLI3) had a significantly reduced expression and one (THEM4) had an increased expression [FDR (false discovery rate) adjusted p-value ≤ 0.05] when compared to monochemosensitive choriocarcinoma (n = 9). The proportion of trophoblast cells and the intensity of immunohistochemical HLA-G expression were reduced in monochemoresistant choriocarcinoma (p < 0.05). In polychemoresistant choriocarcinoma (n = 20) we did not identify differentially expressed genes with an FDR adjusted p-value ≤ 0.05 when compared to polychemosensitive choriocarcinoma (n = 15). Gene pathway analysis revealed a predicted activation of IFN ᵞ in monochemoresistant choriocarcinoma and inhibited IL2 and TNF in polychemoresistant choriocarcinoma. The main biological functions predicted to be altered in chemoresistant choriocarcinoma were related to immunological homeostasis and leukopoiesis.

CONCLUSION

HLA-G is a strong candidate gene to predict choriocarcinoma resistance to monochemotherapy and that further studies are required to implement its routine quantification in the decision process for the management of gestational choriocarcinoma.

A Unique Regulation Region in the 3' UTR of HLA-G with a Promising Potential

Human leukocyte antigen G (HLA-G) is a non-classical human leukocyte antigen (HLA) class I protein that interacts with inhibitory receptors and is commonly overexpressed in various cancers, thereby establishing itself as an inhibitory checkpoint immune ligand. It is also expressed in trophoblast cells during pregnancy and protects the fetus from immune rejection. Despite its crucial role and its intriguing expression pattern, the regulation of HLA-G’s expression is only partially understood. HLA-G’s mRNA is expressed in many tissues but the protein expression is restricted only to the cells mentioned above. Therefore, we suggest that HLA-G is post-transcriptionally regulated. Here, we reveal a distinctive site present only in the 3′ Untranslated region (UTR) of HLA-G, which might explain its unique expression pattern. Consequently, we attempted to find binding factors such as RNA binding proteins (RBPs) and microRNAS (miRs) that regulate HLA-G expression by interacting with this distinct site present in its 3′ UTR. Our research indicates that this site should be further studied in order to reveal its significance.

EGFR aptamer-conjugated liposome-polycation-DNA complex for targeted delivery of SATB1 small interfering RNA to choriocarcinoma cells

Choriocarcinoma is a highly aggressive and vascular cancer. The main treatment for choriocarcinoma is the chemotherapy associated with severe side effects. Therefore, the development of novel strategies to eliminate choriocarcinoma is crucial for increasing the health of women. SATB1 (special AT-rich sequence binding protein 1) participates in tissue-specific gene expression and higher-order chromatin organization, and could promote cancer progression and invasion. For the first time, we hereby demonstrated that the expression of SATB1 was increased by 19 folds in choriocarcinoma cells compared with the normal chorionic cell line, and inhibition of SATB1 expression could markedly inhibit the proliferation of choriocarcinoma cells. Then we developed the gene drug delivery system EGFR-LPDS (epidermal growth factor receptor aptamer-conjugated liposome-polycation-DNA complex loaded with SATB1 siRNA) to increase the delivery and therapeutic effect of SATB1 siRNA against choriocarcinoma cells. The results showed that EGFR-LPDS could specifically target choriocarcinoma cells, resulting in significant inhibition of SATB1 expression, growth inhibitory effect and apoptosis in EGFR over-expressing choriocarcinoma cells in vitro. Notably, EGFR-LPDS could inhibit the expression of SATB1 in choriocarcinoma xenograft in mice, and exhibited the best therapeutic efficacy against mice bearing choriocarcinoma xenograft compared with other controls. Notably, EGFR-LPDS achieved a striking tumor weight inhibitory rate of 81.4%. This is the first report of the therapeutic efficacy of SATB1 siRNA towards choriocarcinoma, and the increased SATB1 siRNA delivery by nanoparticles to choriocarcinoma cells using EGFR aptamers. Thus, EGFR-LPDS represents an up-and coming approach for choriocarcinoma therapy. Considering that there are still limited treatment strategies for choriocarcinoma therapy, patients with choriocarcinoma may be beneficial from this gene therapy.

A balancing act: RNA binding protein HuR/TTP axis in endometriosis patients

Endometriosis, a major reproductive pathology affecting 8-10% of women is characterized by chronic inflammation and immune dysfunction. Human antigen R (HuR) and Tristetraprolin (TTP) are RNA binding proteins that competitively bind to cytokines involved in inflammation including: tumor necrosis factor alpha (TNF-α), granulocyte macrophage colony stimulating factor (GM-CSF), interleukin 6 (IL-6) among others, and stabilize and destabilize them, respectively. The aim of this study was to examine RNA binding protein (RNABP) HuR/TTP axis in endometriosis patients compared to menstrual stage matched healthy fertile controls in hopes of better understanding their contribution to the pathogenesis of endometriosis. Additionally, using a targeted in vitro siRNA approach, we examined whether knock-down of TTP can play a functional role on other RNABPs that competitively bind to inflammatory targets of TTP in both endometriotic and endometrial epithelial cell lines. Our results suggest that RNABPs TTP and HuR are dysregulated in endometriotic lesions compared to matched eutopic patient samples as well endometrium from healthy controls. Silencing of TTP in endometriotic and endometrial epithelial cells revealed differential response to inflammatory cytokines and other RNABPs. Our results suggest potential involvement of HuR/TTP RNA binding protein axis in regulation of inflammation in endometriosis.

Downregulation of the gli transcription factors regulator Kif7 facilitates cell survival and migration of choriocarcinoma cells

The kinesin protein Kif7 has been recognized as an integral component of hedgehog signalling. Aberrant activation of hedgehog signalling has been implicated in many human solid tumours. Gestational trophoblastic disease includes frankly malignant choriocarcinoma and potentially malignant hydatidiform mole. Here we investigated the hedgehog signalling components expression profiles in gestational trophoblastic disease. Downregulation of Gli1, Gli2, Gli3 and Kif7 was demonstrated in clinical samples of choriocarcinoma and hydatidiform moles as well as choriocarcinoma cell lines when compared with normal placentas. Ectopic expression of Kif7 in two choriocarcinoma cell lines JAR and JEG-3 led to a decrease in cell growth and increase in apoptosis demonstrated by MTT and TUNEL assays, respectively. Overexpression of Kif7 also led to suppressed cell migration through transwell assay. In contrast, knocking down Kif7 in HTR-8/SVneo, an immortalized trophoblast cell line, increased cell number over time and increased the migratory ability of the cells. Taken together, Kif7 may contribute to pathogenesis of gestational trophoblastic disease through enhancing survival and promoting dissemination of trophoblasts.

[Expression of C1QBP gene and its correlation with drug resistance in human resistance choriocarcinoma cell line]

OBJECTIVE

To examine the complement component 1 Q subcomponent-binding protein (C1QBP) gene expression in human resistance choriocarcinoma cell lines and its parental cell line JeG-3, and to investigate whether silence C1QBP by small interference RNA could reverse the resistance of human resistance choriocarcinoma cell lines to its relevant chemotherapy drugs.

METHODS

Expression of C1QBP mRNA and protein in cells were detected by real- time fluorogenic quantitative PCR and western blot, respectively. The difference of C1QBP expression was compared between human resistance choriocarcinoma cell lines and its parental cell line JeG-3. Sub-cellular location was proved by confocal immunofluorescence microscopy. A lentiviral vector containing short hairpin RNA (shRNA) targeting C1QBP was constructed and cotransfected with the packaging plasmid mixture into 293T cells by lipofectamine 2000. The human resistance choriocarcinoma cell lines were infected with the packaged lentivirus. Real- time fluorogenic quantitative PCR and western blot were used to validate whether the C1QBP gene expression was silenced. The cell counting kit 8 (CCK8) was used to determine the drug sensitivity.

RESULTS

(1) The C1QBP mRNA expression levels among four human resistance choriocarcinoma cell lines [JeG-3/floxuridiuum (FUDR), JeG- 3/methotrexate (MTX), JeG-3/etoposide (VP), JeG-3/dactinomycin (KSM)] were 2.520 ±0.680, 1.770 ± 0.230, 1.940 ± 0.090 and 1.740 ± 0.350 folds compared to that in JeG- 3 cells. The C1QBP protein was higher expression level in human resistance choriocarcinoma cell lines than that in JeG-3. The immunofluorescence methods and confocal analysis showed that C1QBP localized predominantly in the mitochondrial matrix. (2) The C1QBP mRNA expression in JeG-3/FUDR cells after infected with lentiviral vector were decreased by 93.1% (P < 0.01). The protein expression of C1QBP in JeG-3/FUDR cells after infected with lentiviral vector were almost completely suppressed. The resistance indexes of four human resistance choriocarcinoma cell lines (JeG-3/FUDR, JeG-3/MTX, JeG-3/VP, JeG-3/KSM) were respectively 86.3% , 93.9% , 92.8% and 89.9%, which were decreased remarkably by knockdown the C1QBP expression (P < 0.05).

CONCLUSIONS

C1QBP is overexpressed in human resistance choriocarcinoma cell lines compared with parental cell line JeG-3. Inhibition of C1QBP by lentivirus- mediated small interference RNA could effectively reverses the resistance of human resistance choriocarcinoma cell lines to its relevant chemotherapy drugs.

A novel feeder-free culture system for human pluripotent stem cell culture and induced pluripotent stem cell derivation

Correct interactions with extracellular matrix are essential to human pluripotent stem cells (hPSC) to maintain their pluripotent self-renewal capacity during in vitro culture. hPSCs secrete laminin 511/521, one of the most important functional basement membrane components, and they can be maintained on human laminin 511 and 521 in defined culture conditions. However, large-scale production of purified or recombinant laminin 511 and 521 is difficult and expensive. Here we have tested whether a commonly available human choriocarcinoma cell line, JAR, which produces high quantities of laminins, supports the growth of undifferentiated hPSCs. We were able to maintain several human pluripotent stem cell lines on decellularized matrix produced by JAR cells using a defined culture medium. The JAR matrix also supported targeted differentiation of the cells into neuronal and hepatic directions. Importantly, we were able to derive new human induced pluripotent stem cell (hiPSC) lines on JAR matrix and show that adhesion of the early hiPSC colonies to JAR matrix is more efficient than to matrigel. In summary, JAR matrix provides a cost-effective and easy-to-prepare alternative for human pluripotent stem cell culture and differentiation. In addition, this matrix is ideal for the efficient generation of new hiPSC lines.

Effects of corticotrophin releasing hormone (CRH) on cell viability and differentiation in the human BeWo choriocarcinoma cell line: a potential syncytialisation inducer distinct from cyclic adenosine monophosphate (cAMP)

BACKGROUND

Placental production of corticotrophin releasing hormone (CRH) rises exponentially as pregnancy progresses, and has been linked with the onset of normal and preterm labour. CRH is produced in syncytiotrophoblast cells and production is increased by glucocorticoids and cAMP. It remains unclear whether cAMP acts by inducing differentiation of cytotrophoblasts and/or through induction of syncytialisation. As CRH can stimulate cAMP pathways we have tested whether a feed-forward system may exist in placental cells during syncytialisation.

METHODS

The choriocarcinoma BeWo cell line was treated with cAMP, CRH or vehicle. Cell viability was determined by MTT assay, while apoptosis was analysed by DAPI staining and by FACS. Differentiation was measured by assaying message for hCG and ERVW-1 (syncytin1) by qRT-PCR, as well as the respective protein by ELISA. Fusion of BeWo cells was assessed by co-staining cell membrane and nuclei with CellMask and Hoechst 33342. CRHR1 and CRHR2 mRNA levels were measured by qRT-PCR.

RESULTS

We show that cAMP has an inductive effect on syncytialisation, as evidenced by induction of hCG secretion, by ERVW-1 mRNA expression and by formation of multinuclear cells. CRH mRNA expression was found to increase prior to the changes in the other syncytialisation markers. cAMP had an inhibitory effect on BeWo cell viability, but exogenous CRH did not. However, CRH did mimic the differentiation inducing effect of cAMP, suggesting a link between CRH and cAMP signalling in syncytialisation. We also found that treatment of BeWo cells with exogenous CRH resulted in elevated cellular CRHR1 levels.

CONCLUSIONS

This study suggests a positive feed-forward role exists for CRH in trophoblast cell differentiation, which may underlie the exponential rise in CRH observed as gestation advances.

StarD7 knockdown modulates ABCG2 expression, cell migration, proliferation, and differentiation of human choriocarcinoma JEG-3 cells

Background

StAR-related lipid transfer domain containing 7 (StarD7) is a member of the START-domain protein family whose function still remains unclear. Our data from an explorative microarray assay performed with mRNAs from StarD7 siRNA-transfected JEG-3 cells indicated that ABCG2 (ATP-binding cassette sub-family G member 2) was one of the most abundantly downregulated mRNAs.

Methodology/Principal Findings

Here, we have confirmed that knocking down StarD7 mRNA lead to a decrease in the xenobiotic/lipid transporter ABCG2 at both the mRNA and protein levels (−26.4% and −41%, p<0.05, at 48 h of culture, respectively). Also a concomitant reduction in phospholipid synthesis, bromodeoxyuridine (BrdU) uptake and ³H-thymidine incorporation was detected. Wound healing and transwell assays revealed that JEG-3 cell migration was significantly diminished (p<0.05). Conversely, biochemical differentiation markers such as human chorionic gonadotrophin β-subunit (βhCG) protein synthesis and secretion as well as βhCG and syncytin-1 mRNAs were increased approximately 2-fold. In addition, desmoplakin immunostaining suggested that there was a reduction of intercellular desmosomes between adjacent JEG-3 cells after knocking down StarD7.

Conclusions/Significance

Altogether these findings provide evidence for a role of StarD7 in cell physiology indicating that StarD7 modulates ABCG2 multidrug transporter level, cell migration, proliferation, and biochemical and morphological differentiation marker expression in a human trophoblast cell model.

Role of thoracotomy and metastatectomy in gestational trophoblastic neoplasia: a single center experience

Gestational trophoblastic neoplasia (GTN) is a rare collection of malignancies which are usually curable with modern chemotherapy. Lung metastasis is a relatively common feature of these malignancies and is not considered an adverse prognostic feature. Occasionally, however, the management of these patients necessitates adjuvant thoracic surgery, either to establish the diagnosis or to potentially provide a curative resection of drug-resistant foci of disease. This case series highlights 5 such cases in which thoracic surgery has significantly contributed to the management and outcome of complicated GTN patients, and suggests when thoracic surgery should be considered in this rare group of patients.

HOXC10 is overexpressed in breast cancer and transcriptionally regulated by estrogen via involvement of histone methylases MLL3 and MLL4

HOXC10 is a critical player in the development of spinal cord, formation of neurons, and associated with human leukemia. We found that HOXC10 is overexpressed in breast cancer and transcriptionally regulated by estrogen (17β-estradiol, E(2)). The HOXC10 promoter contains several estrogen response elements (ERE1-7, half-sites). A luciferase-based reporter assay showed that ERE1 and ERE6 of HOXC10 promoter are E(2) responsive. ERα and ERβ play critical roles in E(2)-mediated activation of HOXC10. Knockdown of ERα and ERβ downregulated E(2)-induced HOXC10 expression. ERα and ERβ bind to ERE1 and ERE6 regions in an E(2)-dependent manner. Additionally, knockdown of histone methylases MLL3 and MLL4 (but not MLL1 and MLL2) diminished E(2)-induced expression of HOXC10. MLL3 and MLL4 were bound to the ERE1 and ERE6 regions of HOXC10 promoter in an E(2)-dependent manner. Overall, we demonstrated that HOXC10 is overexpressed in breast cancer, and it is an E(2)-responsive gene. Histone methylases MLL3 and MLL4, along with ERs, regulate HOXC10 gene expression in the presence of E(2).

Genome-wide high-resolution aCGH analysis of gestational choriocarcinomas

Eleven samples of DNA from choriocarcinomas were studied by high resolution CGH-array 244 K. They were studied after histopathological confirmation of the diagnosis, of the androgenic etiology and after a microsatellite marker analysis confirming the absence of contamination of tumor DNA from maternal DNA. Three cell lines, BeWo, JAR, JEG were also studied by this high resolution pangenomic technique. According to aCGH analysis, the de novo choriocarcinomas exhibited simple chromosomal rearrangements or normal profiles. The cell lines showed various and complex chromosomal aberrations. 23 Minimal Critical Regions were defined that allowed us to list the genes that were potentially implicated. Among them, unusually high numbers of microRNA clusters and imprinted genes were observed.

Efflux transporter mRNA expression profiles in differentiating JEG-3 human choriocarcinoma cells as a placental transport model

The kinetics of drug transport across the trophoblast layer is determined by several factors. Human choriocarcinoma cell lines like BeWo and JEG-3 have been used as models of the trophoblast layer to examine the placental transport of drugs. Previously, the drugs examined in these models have been readily transported across the trophoblast layer via cellular gap junctions. These backgrounds enabled us to establish the differentiating JEG-3 cell (DJEG) layer model, which suppresses paracellular drug transport, as an evaluation system of placental drug transport. The efflux transporters on the trophoblast layer assume the meaningful role of protecting the fetus from xenobiotic substances. In order to clarify the usefulness of our DJEG placental drug transport model, this study examined the mRNA expression profiles of the efflux transporters MRPs, MDR1, and BCRP in JEG-3 cells and compared them with those of BeWo cells and their known placental expression. We suggest that the mRNA of efflux transporters MRP 1-8 and BCRP are expressed widely in JEG-3 cells; however, expression levels of MDR1 mRNA were undetectable. It was also indicated that polymorphisms of BCRP C421A in both the BeWo and JEG-3 cells are of the wild-type. We demonstrated the efflux transporters' expression profiles, as well as those of the BeWo cells, was demonstrated in the DJEG placental drug transport evaluating model as well as the BeWo cells, in the DJEG placental drug transport evaluation model. Based on these findings, we hope that the DJEG model will be adequate for use in evaluating placental drug transport in relation to the transporter proteins.

Metastasis gene expression analyses of choriocarcinoma and the effect of silencing metastasis-associated genes on metastatic ability of choriocarcinoma cells

OBJECTIVE

Obtaining choriocarcinoma metastasis-associated genes and identifying the role and mechanism of VEGF-B in the progression of human choriocarcinoma.

STUDY DESIGN

(1) cDNA microarray technique was used to compare the transcriptional profiles between highly metastatic JEG-3 cells and lowly metastatic JAR cells; (2) An inhibitory effect of VEGF-B shRNA was demonstrated by RT-PCR; (3) The effect of VEGF-B shRNA on invasion of JEG-3 cells in vitro was detected by Matrigel invasion assay.

RESULTS

(1) In upregulated genes, 51 genes were correlated with the cell metastasis ability, and FN, MMP-2, uPA, CAV-1 and VEGF-B were the first five genes; (2) Afterwards transfected VEGF-B shRNA, VEGF-B mRNA expression decreased obviously; (3) VEGF-B shRNA transfection significantly downregulated invasion level of JEG-3 cells in vitro (p < 0.05).

CONCLUSION

VEGF-B plays an important role in the metastatic capability of human choriocarcinoma. Reducing the expression of VEGF-B can help weaken the invasion ability of human choriocarcinoma.

Does malaoxon play a role in the geno- and cytotoxic effects of malathion on human choriocarcinoma cells?

This investigation was undertaken to elucidate whether the active metabolite of malathion, malaoxon, has any role in exerting cyto- and genotoxic effects for human choriocarcinoma (JAR) cell line which is an acceptable model for human placental cells. Gas chromatography-mass spectrometry (GC-MS) analysis were separately performed on the cell compartment and supernatant cell culture medium after subjecting the cell line to different malathion concentrations (10-400 μg/mL) and for various incubation periods (0.5 to 24 hours). GC-MS analysis showed that the sonication performed for the disruption of the cells did not cause the chemical change of malathion. The uptake of malathion by the cells was relatively fast. However, the presence of malaoxon, even in trace amounts, could not be confirmed either in samples originating from disrupted cells or in the cell culture medium. Although the hydrolysis of malaoxon occurred in the culture medium, this degradation process could not be counted as a reason for the absence of malaoxon. Since both malathion and malaoxon standard compounds could be accurately detected and distinguished by the applied liquid-liquid extraction and GC-MS methods, one can conclude that, in the case of JAR cells, the parent compound, (i.e. malathion itself) is responsible for the observed in vitro cyto- and genotoxic effects. Our results indicate that the direct toxicity of malathion contributes to the complications of pregnancy observed for environmental malathion exposure.

Calponin 3 regulates actin cytoskeleton rearrangement in trophoblastic cell fusion

Cell-cell fusion is an intriguing differentiation process, essential for placental development and maturation. A proteomic approach identified a cytoplasmic protein, calponin 3 (CNN3), related to the fusion of BeWo choriocarcinoma cells. CNN3 was expressed in cytotrophoblasts in human placenta. CNN3 gene knockdown promoted actin cytoskeletal rearrangement and syncytium formation in BeWo cells, suggesting CNN3 to be a negative regulator of trophoblast fusion. Indeed, CNN3 depletion promoted BeWo cell fusion. CNN3 at the cytoplasmic face of cytoskeleton was dislocated from F-actin with forskolin treatment and diffused into the cytoplasm in a phosphorylation-dependent manner. Phosphorylation sites were located at Ser293/296 in the C-terminal region, and deletion of this region or site-specific disruption of Ser293/296 suppressed syncytium formation. These CNN3 mutants were colocalized with F-actin and remained there after forskolin treatment, suggesting that dissociation of CNN3 from F-actin is modulated by the phosphorylation status of the C-terminal region unique to CNN3 in the CNN family proteins. The mutant missing these phosphorylation sites displayed a dominant negative effect on cell fusion, while replacement of Ser293/296 with aspartic acid enhanced syncytium formation. These results indicated that CNN3 regulates actin cytoskeleton rearrangement which is required for the plasma membranes of trophoblasts to become fusion competent.

Downregulation of caveolin-1 enhances fusion of human BeWo choriocarcinoma cells

Background

Fusion of placental villous cytotrophoblasts with the overlying syncytiotrophoblast is essential for the maintenance of successful pregnancy, and disturbances in this process have been implicated in pathological conditions such as pre-eclampsia and intra-uterine growth retardation. Caveolin-1 has been shown to be expressed in human villous cytotrophoblast and to be downregulated during fusion into syncytiotrophoblast but it is unclear whether it plays a role in this process.

Methodology/Principal Findings

We used RNA interference to determine whether caveolin-1 plays a role in differentiation and fusion in the BeWo choriocarcinoma cell line, a model of villous cytotrophoblast fusion. Assessment of cell fusion by desmosomal protein immunostaining revealed that cells transfected with caveolin-1 siRNA showed significantly enhanced fusion in response to treatment with dibutyryl cyclic AMP compared with cells transfected with a non-silencing control. Furthermore, caveolin-1 knockdown alone was sufficient to promote spontaneous fusion. In addition, biochemical differentiation, assessed by expression of placental alkaline phosphatase, was upregulated in caveolin-1 siRNA-transfected cells, with or without dbcAMP treatment. Assessment of Akt phosphorylation showed that caveolin-1 knockdown resulted in a significant reduction in phosphorylation at Thr³⁰⁸.

Conclusions/Significance

Taken together, these results suggest that caveolin-1 regulates BeWo cell differentiation and fusion, possibly through a mechanism involving modulation of Akt activity.

Thymidylate synthase mRNA expression does not predict resistance to floxuridine in a choriocarcinoma cell line

OBJECTIVE

Pyrimidine antagonist-based chemotherapy is a recommended chemotherapeutic treatment for gestational trophoblastic neoplasia in China. The main reason for treatment failure is chemoresistance. We established a floxuridine (FUDR)-resistant human choriocarcinoma JeG-3/FUDRA sub-line and investigated the role of thymidylate synthase (TS) transcript levels in chemoresistance prediction.

STUDY DESIGN

The JeG-3/FUDRA sub-line was established by intermittent exposure to increasing doses of FUDR. Levels of TS transcripts were measured by real-time fluorescence quantitative reverse transcription-polymerase chain reaction. beta-hCG secretion in these cell lines has also been detected by using a chemoluminescence method.

RESULTS

The JeG-3/FUDRA sub-line had a resistance index of 31.62. When exposed to 5.1 x 10(-7) M FUDR, the secretion of beta-hCG was enhanced dramatically, but with the increasing of the FUDR concentration, it was downregulated gradually. According to the concentration of FUDR exposure from low to high, the multiples of free beta-hCG secretion increased 13.19-, 4.76-, 1.90-, 1.44- and 0.47-fold, respectively. The TS transcript level was down-regulated by exposure to a low concentration of FUDR and then gradually increased with increasing doses of the drug. But when a certain concentration was reached, the expression would not increase but decrease sharply. By sub-lines of different concentration of FUDR exposure varying from low to high, the multiples of increases comparing the TS transcript level to parental cells were 0.56-, 0.42-, 1.02-, 2.78- and 2.06-fold, respectively.

CONCLUSION

We successfully established an FUDR-resistant human choriocarcinoma sub-line and found that the expression of TS mRNA in FUDR-resistant JeG-3 cells was related to the concentration and phase of FUDR exposure. These data suggest that TS mRNA levels would be of limited use as biomarkers for the prediction of chemoresistance to FUDR-based chemotherapy.

MicroRNA-34a suppresses invasion through downregulation of Notch1 and Jagged1 in cervical carcinoma and choriocarcinoma cells

MicroRNAs (miRNAs) are small non-coding RNAs that regulate the expression of other genes by transcriptional inhibition or translational repression. miR-34a is a known tumor suppressor gene and inhibits abnormal cell growth. However, its role in other tumorigenic processes is not fully known. This study aimed to investigate the action of miR-34a on cell invasion. We found that miR-34a is expressed at various levels in cervical cancer (HeLa, SiHa, C4I, C33a and CaSki) and trophoblast (BeWo and JAR) cell lines. Transient forced expression of miR-34a did not affect the proliferation of these cell lines. Computational miRNA target prediction suggested that Notch1 and Jagged1 were targets of miR-34a. By using functional assays, miR-34a was demonstrated to bind to the 3' untranslated regions of Notch1 and Jagged1. Forced expression of miR-34a altered the expression of Notch1 and Jagged1 protein as well as Notch signaling as shown by the response of Hairy Enhancer of Split-1 protein to these treatments using western blot analysis. Forced expression of miR-34a suppressed the invasiveness of HeLa and JAR cells. By using gamma-secretase inhibitor (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester) that interfered Notch signaling and RNA interference that knockdown Notch1 expression, we confirmed that downregulation of Notch1 reduced the invasiveness of the cells. Transfection of intracellular domain of Notch nullifies the effect of miR-34a on the invasiveness of the cells. Besides, we identified that miR-34a affected cell invasion by regulating expression of urokinase plasminogen activator through Notch. Our results provide evidence that miR-34a inhibits invasiveness through regulation of the Notch pathway and its downstream matrix degrading enzyme.

Expression of mTOR and downstream signalling components in the JEG-3 and BeWo human placental choriocarcinoma cell lines

Emerging data suggest that nutritional status and body weight are related to reproductive function, and nutrient imbalances during pregnancy lead to changes in the expression of fetal genes. Recent studies show that the mTOR acts as a placental growth signalling sensor and its expression is down-regulated in intrauterine growth restriction. To date, very little is known about the expression of this signalling pathway in choriocarcinoma, one of the most lethal germ cell cancers. In this study, cultures of fusigenic (BeWo) and non-fusigenic (JEG-3) human choriocarcinoma cell lines were used to investigate the expression of mTOR and its downstream signalling components. The effects of an inducer of syncytialisation (forskolin) on mTOR, eIF4E binding proteins (4EBPs) and ribosomal protein S6 kinases (S6Ks) in BeWo cells were also assessed. RT-PCR studies revealed that mTOR, 4EBP and S6Ks are expressed at mRNA level in both JEG-3 and BeWo cells. Semi-quantitative RT-PCR analysis revealed that in early stages of syncytialisation (50 microM forskolin for 48 h), the expression of mTOR and 4EBP was down-regulated when compared to unstimulated cells. In fully syncytialised cells (50 microM forskolin for 72 h) the expression of both genes was similar to basal levels. Interestingly, the phosphorylation (Ser371, Thr389) status of p70S6K remained unaltered upon forskolin treatment. These data validate BeWo cells as an experimental model to study the effects of forskolin-induced syncytialisation on mTOR signalling.

[Genetic genesis of choriocarcinoma]

OBJECTIVE

To distinguish choriocarcinoma from gestational or non-gestational choriocarcinoma and also identify the causative pregnancy of gestational choriocarcinoma by the genetic origin through molecular genetic analysis.

METHODS

Twelve patients with choriocarcinoma, who had experienced surgery prior to chemotherapy were enrolled in this study. All 12 cases were diagnosed pathologically as choriocarcinoma. Peripheral venous blood samples and formalin-fixed paraffin-embedded blocks of choriocarcinoma tissue microdissected from haematoxylin and eosin-stained sections of tissue by microdissection method were available from the patient and (or) her husband. DNA was then prepared from the couples' blood samples and choriocarcinoma tissue by using standard techniques. PCR amplification and fluorescent microsatellite genotyping were performed by using DNA from the couples and captured choriocarcinoma tissues. The genetic contributions to the choriocarcinoma tissue were determined by comparing the fragments of genes from the choriocarcinoma tissue to those from blood samples of the couples.

RESULTS

The primary lesion was ovary in 7 cases, but only 4 of them had the maternal contribution, indicating a non-gestational origin; the other three were gestational choriocarcinoma. The primary lesion was uterus in 5 cases, which were all gestational choriocarcinoma confirmed by genetic analyses. The causative pregnancies of the 8 cases with gestational choriocarcinoma were identified as androgenetic complete hydatidiform mole (AnCHM) in six cases and normal pregnancies in two cases, respectively.

CONCLUSION

Microsatellite polymorphism analysis is a molecular approach for distinguishing the non-gestational choriocarcinoma from the gestational one, and also be used to identify the causative pregnancy of gestational choriocarcinoma.

Allelic loss of the PTEN gene and mutation of the TP53 gene in choriocarcinoma arising from gastric adenocarcinoma: analysis of loss of heterozygosity in two male patients with extragonadal choriocarcinoma

A tumor suppressor gene at 10q23.3, designated PTEN, encoding a dual-specificity phosphatase with lipid and protein phosphatase activity, has been shown to play an essential role in the pathogenesis of a variety of human cancers. Frequent mutations and deletions of PTEN genes are found in cancer. Little is known, however, about the role that PTEN plays in the pathogenesis of a primary choriocarcinoma derived from gastric adenocarcinoma, an extremely rare choriocarcinoma, or in extragonadal retroperitoneal choriocarcinoma. In this study, genetic alterations occurring in extragonadal choriocarcinoma in two Japanese male patients were examined. Loss of heterozygosity (LOH) analysis using a polymorphic marker of the PTEN gene, IVS4+109ins/delTCTTA, revealed a hemizygous deletion of PTEN not only in the primary gastric choriocarcinoma, but also in the gastric adenocarcinoma. Microsatellite marker D12S1051 likewise showed LOH in both the primary gastric choriocarcinoma and the gastric adenocarcinoma. Mutational analysis of the TP53 gene revealed a point mutation in exon 5 (A536G), which resulted in H179R in the gastric choriocarcinoma but not in the gastric adenocarcinoma. No LOH was found for PTEN in an extragonadal retroperitoneal choriocarcinoma. Microsatellite marker D9S162 showed LOH in the extragonadal retroperitoneal choriocarcinoma, but not in the primary gastric choriocarcinoma. These results indicate that LOH of the PTEN gene and of D12S1051 is the molecular pathogenesis of the gastric adenocarcinoma, and the mutation of the TP53 gene is an additional hit for the oncogenesis of choriocarcinoma arising from gastric adenocarcinoma. However, LOH of the PTEN gene is not a common molecular event for pathogenesis of extragonadal choriocarcinoma. In addition, it was found that expression of PTEN is significantly decreased in the nuclei of syncytiotrophoblast-like cancer cells, compared with those of cytotrophoblast-like cancer cells in choriocarcinoma.

Interleukin-11 increases invasiveness of JEG-3 choriocarcinoma cells by modulating STAT3 expression

Amongst the interleukin-6 (IL-6) family of cytokines, leukemia inhibitory factor (LIF) has been shown to promote trophoblast invasion and proliferation. In the present study interleukin-11 (IL-11), another member of the IL-6 family, was investigated for its role in regulating invasion, migration and proliferation of JEG-3 choriocarcinoma cells. JEG-3 cells, like extra villous trophoblast (EVT), express mRNA transcripts encoding IL-11 and IL-11 receptor-alpha (IL-11Ralpha). Treatment of JEG-3 cells with IL-11 led to an increase in invasion across Matrigel extracellular matrix without an increase in proliferation. There was a dose-dependent increase in activation of STAT3 under the influence of IL-11 with maximum Tyr705 phosphorylation by 10min. In addition, treatment of JEG-3 cells with IL-11 for 24h led to an increase in expression of unphosphorylated STAT1 and STAT3. Analysis of the nuclear fraction showed an increased localization of STAT3 following IL-11 treatment while STAT1 was absent. Silencing the expression of STAT3 by siRNA caused a 25% reduction in invasion compared to control cells, however this was not significant. Furthermore, treatment of STAT3-silenced JEG-3 cells with IL-11 led to a significant increase in invasion compared to STAT3-silenced cells without cytokine, but this was not significant compared to non-transfected control cells. Silencing the expression of gp130 but not of IL-6R abrogated the increase in invasiveness of JEG-3 cells following IL-11 treatment. In conclusion, activation and upregulation of STAT3 appears to be critical for the IL-11-mediated increase in invasiveness of JEG-3 cells.

Diagnostic and prognostic significance of circulating tumor suppressor gene p53 autoantibodies in patients with gestational trophoblastic tumors

Seventy-two patients with gestational trophoblastic tumors (GTTs) and 20 first-trimester healthy pregnant women (controls) participated in this study. According to the WHO scoring system, GTTs were subgrouped into 24 hydatiform mole spontaneous regression (HMSR), 18 postmolar high-risk (PMHR) and 16 low- and 14 high-risk cases of choriocarcinoma. Patients with choriocarcinoma were treated with hysterectomy and methotrexate chemotherapy, whereas molar pregnancy was managed by either oxytocin infusion followed by suction evacuation or by hysterectomy. Serum p53 autoantibodies were determined by enzyme-linked immunosorbant assay and serum hCGbeta was determined by radioimmunoassay before and throughout the 12 months after treatment. p53 autoantibodies were not detected in normal pregnancy and cases of HMSR but were detected in all cases of PMHR and choriocarcinoma. Concentrations of p53 autoantibodies were higher in choriocarcinoma than in PMHR cases. Serial measurements of p53 autoantibodies dropped to an undetectable level within 1 and 6 months after treatment in cases of PMHR and low-risk choriocarcinoma, respectively. Decreasing values of p53 autoantibodies in high-risk choriocarcinoma remained higher than the cut-off level of controls. There was a significant positive correlation between p53 autoantibodies and serum hCGbeta concentration in GTTs. In conclusion, detection of p53 autoantibodies has a high potential for the differential diagnosis of GTTs and their serial measurements are clinically useful to monitor disease progression and to assess response to therapy in GTTs.

Transcription regulation in differential expression of the human GSTP1 gene in breast and choriocarcinoma cells

Glutathione S-transferase P1 is a major phase II detoxification enzyme in most cell types. Aberrant expression of GSTP1 is associated with carcinogenesis and development of multidrug resistance. GSTP1 gene transcription is regulated by promoter methylation and by transcription factors. To elucidate the mechanisms responsible for the different levels of GSTP1 expression observed in Hbl-100 and BeWo cells we utilized truncated promoter constructs to compare the functional role of different promoter elements. We also identified transcription factors binding the responsive elements by electrophoretic mobility shift assay. The applied approaches provided the evidence that binding of transcription factors to ARE, CRE and NF-kappaB sites are responsible for the cell specific levels of GSTP1 expression in Hbl-100 and BeWo cells. It was also indicated that partial promoter methylation occurs in BeWo cells.

Stimulating the GPR30 estrogen receptor with a novel tamoxifen analogue activates SF-1 and promotes endometrial cell proliferation

Estrogens and selective estrogen receptor (ER) modulators such as tamoxifen are known to increase uterine cell proliferation. Mounting evidence suggests that estrogen signaling is mediated not only by ERalpha and ERbeta nuclear receptors, but also by GPR30 (GPER), a seven transmembrane (7TM) receptor. Here, we report that primary human endometriotic H-38 cells express high levels of GPR30 with no detectable ERalpha or ERbeta. Using a novel tamoxifen analogue, STX, which activates GPR30 but not ERs, significant stimulation of the phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways was observed in H-38 cells and in Ishikawa endometrial cancer cells expressing GPR30; a similar effect was observed in JEG3 choriocarcinoma cells. STX treatment also increased cellular pools of phosphatidylinositol (3,4,5) triphosphate, a proposed ligand for the nuclear hormone receptor SF-1 (NR5A1). Consistent with these findings, STX, tamoxifen, and the phytoestrogen genistein were able to increase SF-1 transcription, promote Ishikawa cell proliferation, and induce the SF-1 target gene aromatase in a GPR30-dependent manner. Our findings suggest a novel signaling paradigm that is initiated by estrogen activation of the 7TM receptor GPR30, with signal transduction cascades (PI3K and MAPK) converging on nuclear hormone receptors (SF-1/LRH-1) to modulate their transcriptional output. We propose that this novel GPR30/SF-1 pathway increases local concentrations of estrogen, and together with classic ER signaling, mediate the proliferative effects of synthetic estrogens such as tamoxifen, in promoting endometriosis and endometrial cancers.

Placenta-specific methylation of the vitamin D 24-hydroxylase gene: implications for feedback autoregulation of active vitamin D levels at the fetomaternal interface

Plasma concentrations of biologically active vitamin D (1,25-(OH)(2)D) are tightly controlled via feedback regulation of renal 1alpha-hydroxylase (CYP27B1; positive) and 24-hydroxylase (CYP24A1; catabolic) enzymes. In pregnancy, this regulation is uncoupled, and 1,25-(OH)(2)D levels are significantly elevated, suggesting a role in pregnancy progression. Epigenetic regulation of CYP27B1 and CYP24A1 has previously been described in cell and animal models, and despite emerging evidence for a critical role of epigenetics in placentation generally, little is known about the regulation of enzymes modulating vitamin D homeostasis at the fetomaternal interface. In this study, we investigated the methylation status of genes regulating vitamin D bioavailability and activity in the placenta. No methylation of the VDR (vitamin D receptor) and CYP27B1 genes was found in any placental tissues. In contrast, the CYP24A1 gene is methylated in human placenta, purified cytotrophoblasts, and primary and cultured chorionic villus sampling tissue. No methylation was detected in any somatic human tissue tested. Methylation was also evident in marmoset and mouse placental tissue. All three genes were hypermethylated in choriocarcinoma cell lines, highlighting the role of vitamin D deregulation in this cancer. Gene expression analysis confirmed a reduced capacity for CYP24A1 induction with promoter methylation in primary cells and in vitro reporter analysis demonstrated that promoter methylation directly down-regulates basal promoter activity and abolishes vitamin D-mediated feedback activation. This study strongly suggests that epigenetic decoupling of vitamin D feedback catabolism plays an important role in maximizing active vitamin D bioavailability at the fetomaternal interface.

Mechanisms of matrix metalloproteinase-2 (mmp-2) transcriptional repression by progesterone in jar choriocarcinoma cells

BACKGROUND

Although the MMP-2 promoter lacks a canonical progesterone response element (PRE), the hormone inhibits MMP-2 expression and is part of treatment protocols in gynecological invasive pathologies, including endometriosis and endometrial hyperplasia. This study aimed to explore the mechanism by which progesterone inhibits MMP-2 expression.

METHODS

The effect of progesterone on MMP-2 expression in the JAR human choriocarcinoma cell line was analyzed by gelatin zymography. MMP-2 transcript expression was studied using Northern blot and semi-quantitative RT-PCR. Rat promoter deletion analysis, electrophoretic mobility shift and chromatin immuno-precipitation assays were performed in order to locate the DNA binding site and the transcription factors involved in MMP-2 regulation.

RESULTS

Progesterone significantly decreased secretion of pro-MMP-2 and MMP-2 transcript expression level in a dose-dependent manner. Progesterone (1 microM) significantly decreased both human and rat MMP-2 promoter activity (80.1% +/- 0.3 and 81.3% +/- 0.23, respectively). Progesterone acts through the SP1 family transcription factors-binding site, located between -1433 and -1342 bp region from the transcriptional start site of the rat MMP-2 promoter, which are present in the orthologous human MMP-2 promoter. Progesterone receptor (PR), SP2, SP3 and SP4 proteins are constitutively bound to this consensus sequence.

CONCLUSION

Progesterone reduces PR and SP4 binding to the MMP-2 promoter, thereby suppressing transcription. Progesterone also promotes SP4 degradation. These novel mechanisms of MMP-2 regulation by progesterone provide the biological rationale for the use of progesterone in clinical settings associated with increased MMP-2 expression.

Expression and activity of vitamin D receptor in the human placenta and in choriocarcinoma BeWo and JEG-3 cell lines

Vitamin D receptor (VDR) regulates the expression of many genes involved in mineral metabolism, cellular proliferation, differentiation and drug biotransformation. We studied the expression and activity of VDR and its heterodimerization partner retinoid X receptor-alpha (RXRalpha) in choriocarcinoma trophoblast cell lines BeWo and JEG-3, in comparison with human isolated placental cytotrophoblasts and human full term placenta. We found that VDR and RXRalpha are localised in the human term placenta trophoblast and expressed in isolated cytotrophoblasts. However, we found low expression and no transcriptional activity of VDR in used choriocarcinoma cell lines. The inhibitor of DNA methylation, 5-deoxy-3'-azacytidine, and histone deacetylase inhibitor sodium butyrate partially restored the expression of VDR, suggesting an epigenetic suppression of the gene in choriocarcinoma cells. Differentiation of BeWo cells resulted in up-regulation of VDR mRNA. Finally, we observed a non-genomic effect of 1,25(OH)(2)D(3) in the activation of the extracellular signal-regulated kinase (ERK) signalling pathway in JEG-3 cells. In conclusion, our results suggest an epigenetic repression of VDR gene expression and activity in choriocarcinoma cell lines, and a non-genomic effect of 1,25(OH)(2)D(3) in JEG-3 cells.

PDCD1, CTLA-4 and p53 gene polymorphism and susceptibility to gestational trophoblastic diseases

OBJECTIVE

Gestational trophoblastic neoplasms (also termed gestational trophoblastic diseases [GTDs]) encompass a spectrum of interrelated tumors originating from trophoblasts. The search is ongoing for identification of the culpable gene defects in GTDs. Considering the role of PDCD1, CTLA-4 and p53 genes in immune regulation and tumor progression, we explored the association of single-nucleotide polymorphisms (SNPs) corresponding to each gene and GTDs.

STUDY DESIGN

In a genetic association study, PD1.5 (7785) C/T, CTLA-4 +49 A/G, and p53 codon 72 Arg/Pro SNPs were genotyped in case-control groups with patient/control ratios of 92:295, 83:84 and 85:150, respectively.

RESULTS

The C/T genotype of the PDCD1 gene was significantly more prevalent among patients with GTDs (40.2%) than controls (19%) (odds ratio [OR] = 2.87; 95% CI = 1.72, 4.77; p < 0.001). Moreover, the C allele was present in 65.8% of patients and 49.5% of controls (OR = 1.96; 95% CI = 1.38, 2.76; p < 0.001). There was no difference in the distribution of each genotype or allele between patients with GTDs and controls considering other studied SNPs.

CONCLUSION

The results of the current study demonstrate that SNPs in the PDCD1 gene confer susceptibility to GTDs, while there is no association between CTLA-4 and p53 gene polymorphisms and GTDs in an Iranian population.

STOX1 overexpression in choriocarcinoma cells mimics transcriptional alterations observed in preeclamptic placentas

BACKGROUND

Mutations in STOX1 were proposed to be causal for predisposing to preeclampsia, a hypertensive disorder originating from placental defects, affecting up to 10% of human pregnancies. However, after the first study published in 2005 three other groups have dismissed the polymorphism described in the first paper as a causal mutation.

METHODOLOGY AND PRINCIPAL FINDINGS

In the present study, we have produced a choriocarcinoma cell line overexpressing STOX1. This overexpression results in transcriptional modification of 12.5% of the genes, some of them being direct targets as shown by chromatin immunoprecipitation. STOX1 overexpression correlates strongly and specifically with transcriptomic alterations in preeclamptic placentas (r = 0.30, p = 9.10(-7)). Numerous known key modulators of preeclampsia (such as Endoglin, Syncytin, human chorionic gonadotrophin -hCG-, and Glial Cell Missing Homolog -GCM1-) were modified in these transformed choriocarcinoma cells.

CONCLUSIONS

Our results contribute to reconcile contradictory data concerning the involvement of STOX1 in preeclampsia. In addition, they strongly suggest that anomalies in STOX1 expression are associated with the onset of preeclampsia, thus indicating that this gene should be the target of future studies. Our cellular model could constitute an invaluable resource for studying specific aspects of this human disease.

Interleukin-18 gene promoter polymorphisms in women with gestational trophoblastic diseases

OBJECTIVE

Gestational trophoblastic diseases (GTDs) consist of a spectrum of disorders characterized by an abnormal proliferation of trophoblastic tissue. IL-18 is a pleiotropic cytokine with a capacity for both ThI and Th2 polarization. Considering the association of IL-18 promoter polymorphisms at positions -607 (A/C) and -137 (C/G) with pregnancy events and some cancers, we sought to examine these polymorphisms in Iranian patients with GTD, their association with disease subtypes, and IL-18 serum level.

STUDY DESIGN

Single nucleotide polymorphisms (SNPs) were analyzed by allele-specific polymerase chain reaction in 92 patients with GTDs and 103 healthy pregnant controls. IL-18 serum level was determined using ELISA method.

RESULTS

No significant association was found between the allele, genotype, genotype combination and haplotype distribution of these SNPs and GTDs or its subgroups. Mean IL-18 serum level was significantly higher in patients with choriocarcinoma and pregnant controls compared with nonpregnant controls (p = 0.04, 0.04 and 0.001, respectively). -137 GG genotype pregnant controls had a significantly higher IL-18 serum level compared with CC genotype.

CONCLUSION

IL-18 promoter polymorphisms do not confer susceptibility to GTDs or its variants; however, their functional significance is demonstrated in this study. Furthermore, IL-18 serum level increases in GTDs and in normal pregnancy.

Establishment and Characterization of a Human Gestational Choriocarcinoma Cell Line (HOCC)

Human gestational choriocarcinoma cell line (HOCC) was established from the mouse graft of choriocarcinoma. The HOCC cells were spindle or polygonal in shape and multi-nucleated giant cells, showing neoplastic and pleomorphic features. The cell proliferated stably, and the population doubling time was about 32 hours. The chromosome numbers showed a wide distribution of aneuploidy, the mode was in hypertriploid range and the marker chromosomes were recognized in the several generations. Heterotransplantation was easy, and subcutaneous transplantation of 1 X 10(7) cells in nude mouse formed a tumor composed of choriocarcinoma. It is most noteworthy characteristic of the cell line that it produced human chorionic gonadotropin (hCG) in an in vitro culture system and in vivo in nude mice.

Indoleamine 2,3-dioxygenase expression in gestational trophoblastic disease: implications for development of immunotherapeutic approaches

OBJECTIVE

To examine the immunoexpression of indoleamine 2,3-dioxygenase (IDO) in gestational trophoblastic neoplasia (GTN), including hydatidiform moles and gestational trophoblastic tumors.

STUDY DESIGN

GTN cases were identified from a referral center for trophoblastic disease, and sections were immunostained with anti-IDO antibody and classified as positive or negative for trophoblast staining relative to normal chorionic villi.

RESULTS

Fifty-two cases were included: 10 nonmolar hydropic miscarriages (HA), 11 partial moles (PHM), 9 complete moles (CHM), 15 choriocarcinoma cases (CC) and 7 placental site trophoblastic tumors (PSTT). All HA, PHM and CHM demonstrated IDO staining; 2 of 15 CC were strongly positive, 6 demonstrated focal positivity (< 10% of tumor cells), and the remainder were negative. Of the 7 PSTT, only 2 showed focal weak positivity; the others were negative.

CONCLUSION

Hydatidiform moles express IDO, but the majority of gestational trophoblastic tumors, despite arising from villous or nonvillous trophoblast, do not express this enzyme, suggesting that IDO-mediated immunoregulation is unlikely to be a major component of the malignant phenotype in these tumors. Immunotherapeutic approaches involving IDO might represent ancillary approaches in a minority of patients with GTN.

Gene expression profiling during Forskolin induced differentiation of BeWo cells by differential display RT-PCR

The differentiation of cytotrophoblasts into syncytiotrophoblasts in the placenta has been employed as a model to investigate stage specific expression as well as regulation of genes during this process. While the cytotrophoblasts are highly invasive and proliferative with relatively less capacity to synthesize pregnancy related proteins, the multinucleated syncytiotrophoblasts are non-proliferative and non-invasive. However, syncytiotrophoblasts are the site of synthesis of a variety of protein, peptide and steroid hormones as well as several growth factors. Both the freshly isolated cytotrophoblasts from human placenta as well as the BeWo cell, a choriocarcinoma cell line model which retain several characteristic of cytotrophoblasts has been employed by us to study regulation of differentiation. In the present study, we have employed the differential display RT-PCR analysis (DD-RT-PCR) to evaluate gene expression changes during Forskolin induced in vitro differentiation of BeWo cells. We have identified several genes which are differentially expressed during differentiation and the differential expression of 10 transcripts was confirmed by Northern blot analysis. Based on the identity of the transcripts an attempt has been made to relate the known function of the gene products, to changes observed during differentiation. Of the several transcripts, one of the transcripts, namely Secretory Leukocyte Protease Inhibitor (SLPI) which is known to have multiple functions was found to increase 15-fold in the syntiotrophoblast.

Ad-PUMA sensitizes drug-resistant choriocarcinoma cells to chemotherapeutic agents

PURPOSE/OBJECTIVE

To investigate whether exogenous PUMA expression suppresses the growth of drug-resistant choriocarcinoma cells and sensitizes them to chemotherapeutic agents.

METHODS

An adenovirus expressing PUMA (Ad-PUMA), alone or in combination with chemotherapeutic agents (5-FU, vp16, MTX), was used to treat drug-resistant choriocarcinoma cells jeg-3/vp16 and parental jeg-3. The growth inhibitory and proapoptotic effects of Ad-PUMA both in vitro and in vivo were examined. The mechanisms of PUMA-mediated growth suppression and apoptosis were investigated by an analysis of caspase 3 activation and the change of mitochondrial membrane potential. The levels of PUMA, p53 and caspase 3 were detected by Western blotting.

RESULT

PUMA was expressed lower in jeg-3/vp16 than in jeg-3. jeg-3/vp16 responded much less sensitively to 5-FU and vp16 treatment than jeg-3, though PUMA was up-regulated in both cells. Exogenous PUMA expression resulted in potent growth suppression of jeg-3/vp16 and jeg-3 through induction of apoptosis. Ad-PUMA sensitized jeg-3 and jeg-3/vp16 to chemotherapeutic agents. When Ad-PUMA 10MOI and 5-FU, vp16 or MTX were combined respectively, IC50 of drugs decreased by 8.66-, 18.66- and 13.06-fold compared with those treated by anticancer drugs alone in jeg-3/vp16, while in jeg-3, IC50 decreased only by 1.80-, 1.78- and 2.76-fold. Ad-PUMA restored the sensitivity of choriocarcinoma cells to chemotherapeutic agents by enhancing apoptosis induced by anticancer drugs. Similar results could be observed in vivo. Xenograft tumors were inhibited by Ad-PUMA or vp16. In the drug-resistant group, the inhibitory rate increased from 14.57% to 78.93% in vp16 and vp16 combined with Ad-PUMA subgroups. While in the parental group, the inhibitory rate increased but slightly, from 66.39% to 71.56%.

CONCLUSION

PUMA is an important player in the therapeutic responses to chemotherapeutic agents of choriocarcinoma cells. In addition to its role in inhibiting tumor growth, low dose of Ad-PUMA significantly restored the sensitivity of choriocarcinoma cells to chemotherapeutic agents in vitro and in vivo. Exogenous PUMA is potentially useful as a sensitizer in treating drug-resistant choriocarcinoma.

The N-terminus domain of the a2 isoform of vacuolar ATPase can regulate interleukin-1beta production from mononuclear cells in co-culture with JEG-3 choriocarcinoma cells

PROBLEM

a2V-ATPase is the a2 isoform of vacuolar ATPase and is expressed in human trophoblast cells. a2V-ATPase resides as a 70-kDa molecule in intracellular vesicles. Upon cell stimulation, it migrates to the surface as a 50-kDa molecule, after a 20-kDa portion [N-terminus domain of the a2V-ATPase (a2NTD)] is cleaved and secreted to the extracellular environment. Previous studies showed that a2NTD-regulated cytokine production from stimulated T cells. The aim of this study was to determine if a2NTD can regulate cytokine production from immune cells that were in contact with JEG-3 cells.

METHOD OF STUDY

Peripheral blood mononuclear cells (PBMC) from females were co-cultured with JEG-3 cells in the presence or absence of a2NTD, and supernatants were analyzed by enzyme-linked immunosorbent assay for interleukin (IL)-1beta. Additionally, PBMC cultured with JEG-3 cells, in the presence or absence of a2NTD, were analyzed for cytokine gene expression by gene arrays.

RESULTS

There was an increased secretion of IL-1beta and a decrease in type I and II IL-1 receptors (IL1RA and IL-1R2) gene expression in PBMC that were co-cultured with JEG-3 cells in the presence of a2NTD.

CONCLUSION

These data suggest a role for a2NTD in the regulation of IL-1beta pro-inflammatory cytokine production at the fetal-maternal interface.

Mixed Ovarian Germ Cell Tumor in a BRCA2 Mutation Carrier

BRCA2 germ-line mutations confer an increased risk of developing breast and ovarian cancer. We report the occurrence of a mixed ovarian germ cell tumor (GCT) (50% embryonal carcinoma, 20%-25% choriocarcinoma, 10%-15% dysgerminoma, and 10%-15% immature teratoma) in a 33-year-old Ashkenazi Jewish woman, carrier of the BRCA2:6174delT mutation. The mutation is also present in the patient's father, who was diagnosed with breast cancer at age 59 and with prostate cancer at age 69. This is the first report of a GCT in a BRCA2 mutation carrier; there was one previous report of an ovarian dysgerminoma in a BRCA1 carrier. Molecular analysis of the proband's tumor DNA revealed there was no loss of heterozygosity of the wild-type allele in the tumor, as is usually the case for epithelial BRCA-related ovarian tumors. This suggests either that biallelic inactivation of BRCA2 is not required for GCT development or that this is a chance event unrelated to the presence of the mutation.