Paradoxical Discrepancy Between the Serum Level and the Placental Intensity of PP5/TFPI-2 in Preeclampsia and/or Intrauterine Growth Restriction: Possible Interaction and Correlation with Glypican-3 Hold the Key

Maternal plasma syndecan-1: a biomarker for fetal growth restriction

OBJECTIVE

The identification of fetal growth disorders is an important clinical priority given that they increase the risk of perinatal morbidity and mortality as well as long-term diseases. A subset of small-for-gestational-age (SGA) infants are growth-restricted, and this condition is often attributed to placental insufficiency. Syndecan-1, a product of the degradation of the endothelial glycocalyx, has been proposed as a biomarker of endothelial damage in different pathologies. During pregnancy, a "specialized" form of the glycocalyx-the "syncytiotrophoblast glycocalyx"-covers the placental villi. The purpose of this study was to determine whether the concentration of maternal plasma syndecan-1 can be proposed as a biomarker for fetal growth restriction.

STUDY DESIGN

A cross-sectional study was designed to include women with normal pregnancy (n = 130) and pregnant women who delivered an SGA neonate (n = 50). Doppler velocimetry of the uterine and umbilical arteries was performed in women with an SGA fetus at the time of diagnosis. Venipuncture was performed within 48 h of Doppler velocimetry and plasma concentrations of syndecan-1 were determined by a specific and sensitive immunoassay.

RESULTS

(1) Plasma syndecan-1 concentration followed a nonlinear increase with gestational age in uncomplicated pregnancies (R² = 0.27, p < .001); (2) women with a pregnancy complicated with an SGA fetus had a significantly lower mean plasma concentration of syndecan-1 than those with an appropriate-for-gestational-age fetus (p = .0001); (3) this difference can be attributed to fetal growth restriction, as the mean plasma syndecan-1 concentration was significantly lower only in the group of women with an SGA fetus who had abnormal umbilical and uterine artery Doppler velocimetry compared to controls (p = .00071; adjusted p = .0028). A trend toward lower syndecan-1 concentrations was also noted for SGA with abnormal uterine but normal umbilical artery Doppler velocimetry (p = .0505; adjusted p = .067); 4) among women with an SGA fetus, those with abnormal umbilical and uterine artery Doppler findings had a lower mean plasma syndecan-1 concentration than women with normal Doppler velocimetry (p = .02; adjusted p = .04); 5) an inverse relationship was found between the maternal plasma syndecan-1 concentration and the umbilical artery pulsatility index (r = -0.5; p = .003); and 6) a plasma syndecan-1 concentration ≤ 850 ng/mL had a positive likelihood ratio of 4.4 and a negative likelihood ratio of 0.24 for the identification of a mother with an SGA fetus who had abnormal umbilical artery Doppler velocimetry (area under the ROC curve 0.83; p < .001).

CONCLUSION

Low maternal plasma syndecan-1 may reflect placental diseases and this protein could be a biomarker for fetal growth restriction. However, as a sole biomarker for this condition, its accuracy is low.

Tissue factor pathway inhibitor 2: Current understanding, challenges, and future perspectives

AIM

Tissue factor pathway inhibitor 2 (TFPI2) is a structural homolog of tissue factor pathway inhibitor 1 (TFPI1). Since TFPI2 is a placenta-derived protein, dynamic changes in TFPI2 levels may be related to pregnancy-related diseases. Furthermore, TFPI2 has been reported to be a novel serum biomarker for detecting ovarian cancer, especially clear cell carcinoma (CCC). This review aims to summarize the current knowledge on the biological function of TFPI2, highlight the major challenges that remain to be addressed, and discuss future research directions.

METHODS

Papers published up to March 31, 2023 in the PubMed and Google Scholar databases were included in this review. We also provide novel complementary information to what is known about the action of TFPI2.

RESULTS

Since TFPI2 concentrations in the blood of pregnant women, preeclampsia patients, and cancer patients vary greatly, its pathophysiological functions have attracted attention. Downregulation of TFPI2, a tumor-suppressor gene, by hypermethylation may contribute to the progression of several cancers. On the other hand, TFPI2 overexpressed in CCC is a risk factor for the development of thrombosis, possibly through inhibition of plasmin activity. However, agreement on the biological function of TFPI2 is still lacking and there are many scientific questions to be addressed. In particular, the lack of international standardization for the quantification of TFPI2 concentrations makes it difficult for researchers and clinicians to evaluate, pool, and compare data from different studies across countries.

DISCUSSION

This review summarizes current understandings and challenges in TFPI2 research and discusses future perspectives.

The role of tissue factor pathway inhibitor 2 in the coagulation and fibrinolysis system

AIM

Tissue factor (TF), the primary initiator of the extrinsic coagulation pathway, contributes to the generation of a hypercoagulable and prothrombotic state in cancer patients. TF pathway inhibitor (TFPI) is a major inhibitor of TF-mediated coagulation pathway. The two proteins, TFPI1 and TFPI2, are encoded by separate genes. Indeed, various cancer patients with venous thromboembolism (VTE) had significantly lower TFPI1 levels than those without VTE. In contrast, serum TFPI2 level was found to increase in ovarian cancer patients with VTE. It remains unclear why TFPI2, unlike TFPI1, is elevated in ovarian cancer patients with VTE. The aim of this review is to explore the pathophysiological role of TFPI2 on the coagulation and fibrinolysis system.

METHODS

A literature search was performed from inception to April 30, 2022 in the PubMed and Google Scholar databases.

RESULTS

TFPI1 and TFPI2 are homologs with different protease inhibitory activities in the coagulation and fibrinolysis system. TFPI1 inhibits TF/factor VIIa (FVIIa) catalyzed factor X (FX) activation. On the other hand, TFPI2 is unlikely to affect TF-initiated thrombin generation, but it has strong inhibitory activity against plasmin. Plasmin is involved in fibrin degradation, clot lysis, and inactivation of several coagulation factors (such as FV, FVIII, FIX, and FX). TFPI2 may increase the risk of VTE by inhibiting plasmin-dependent fibrinolysis.

CONCLUSION

TFPI1 and TFPI2 may have different key functions in regulating the coagulation and fibrinolytic systems.

Tissue Factor Pathway Inhibitors as Potential Targets for Understanding the Pathophysiology of Preeclampsia

BACKGROUND

Preeclampsia is a hypertensive disorder of pregnancy that causes maternal and perinatal morbidity and mortality worldwide. Preeclampsia is associated with complex abnormalities of the coagulation and fibrinolytic system. Tissue factor (TF) is involved in the hemostatic system during pregnancy, while the Tissue Factor Pathway Inhibitor (TFPI) is a major physiological inhibitor of the TF-initiated coagulation cascade. The imbalance in hemostatic mechanisms may lead to a hypercoagulable state, but prior research has not comprehensively investigated the roles of TFPI1 and TFPI2 in preeclamptic patients. In this review, we summarize our current understanding of the biological functions of TFPI1 and TFPI2 and discuss future directions in preeclampsia research.

METHODS

A literature search was performed from inception to 30 June 2022 in the PubMed and Google Scholar databases.

RESULTS

TFPI1 and TFPI2 are homologues with different protease inhibitory activities in the coagulation and fibrinolysis system. TFPI1 is an essential physiological inhibitor of the TF-initiated extrinsic pathway of coagulation. On the other hand, TFPI2 inhibits plasmin-mediated fibrinolysis and exerts antifibrinolytic activity. It also inhibits plasmin-mediated inactivation of clotting factors and maintains a hypercoagulable state. Furthermore, in contrast to TFPI1, TFPI2 suppresses trophoblast cell proliferation and invasion and promotes cell apoptosis. TFPI1 and TFPI2 may play important roles in regulating the coagulation and fibrinolytic system and trophoblast invasion to establish and maintain successful pregnancies. Concentrations of TF, TFPI1, and TFPI2 in maternal blood and placental tissue are significantly altered in preeclamptic women compared to normal pregnancies.

CONCLUSIONS

TFPI protein family may affect both the anticoagulant (i.e., TFPI1) and antifibrinolytic/procoagulant (i.e., TFPI2) systems. TFPI1 and TFPI2 may function as new predictive biomarkers for preeclampsia and navigate precision therapy.

Proteoglycans: Systems-Level Insight into Their Expression in Healthy and Diseased Placentas

Proteoglycan macromolecules play key roles in several physiological processes (e.g., adhesion, proliferation, migration, invasion, angiogenesis, and apoptosis), all of which are important for placentation and healthy pregnancy. However, their precise roles in human reproduction have not been clarified. To fill this gap, herein, we provide an overview of the proteoglycans' expression and role in the placenta, in trophoblast development, and in pregnancy complications (pre-eclampsia, fetal growth restriction), highlighting one of the most important members of this family, syndecan-1 (SDC1). Microarray data analysis showed that of 34 placentally expressed proteoglycans, SDC1 production is markedly the highest in the placenta and that SDC1 is the most upregulated gene during trophoblast differentiation into the syncytiotrophoblast. Furthermore, placental transcriptomic data identified dysregulated proteoglycan genes in pre-eclampsia and in fetal growth restriction, including SDC1, which is supported by the lower concentration of syndecan-1 in maternal blood in these syndromes. Overall, our clinical and in vitro studies, data analyses, and literature search pointed out that proteoglycans, as important components of the placenta, may regulate various stages of placental development and participate in the maintenance of a healthy pregnancy. Moreover, syndecan-1 may serve as a useful marker of syncytialization and a prognostic marker of adverse pregnancy outcomes. Further studies are warranted to explore the role of proteoglycans in healthy and complicated pregnancies, which may help in diagnostic or therapeutic developments.

Toward an understanding of tissue factor pathway inhibitor-2 as a novel serodiagnostic marker for clear cell carcinoma of the ovary

AIMS

Tissue factor pathway inhibitor (TFPI)-2 has recently emerged as a serodiagnostic marker for patients with epithelial ovarian cancer (EOC), especially clear cell carcinoma (CCC). This review discusses the biological properties of TFPI-2 and why serum levels are elevated in CCC patients.

METHODS

A comprehensive literature search was conducted in PubMed up until March, 2021.

RESULTS

TFPI-2 is a Kunitz-type protease inhibitor and negatively regulates the enzymatic activities, such as plasmin. TFPI-2 has been characterized as a tumor suppressor gene and was frequently downregulated through promoter hypermethylation in various human cancers. In contrast, TFPI-2 was overexpressed only in CCC. TFPI-2 may be involved in the pathophysiology of CCC, possibly through regulation of coagulation system, stabilization of extracellular matrix (ECM), and induction of intracellular signal transduction. TFPI-2 suppresses tissue factor-induced hypercoagulation in a hypoxic environment. TFPI-2, secreted by CCC cells, platelets, and adjacent vascular endothelial cells, may suppress tumor growth and invasion through ECM remodeling. Nuclear TFPI-2 may suppress matrix metalloproteinase production via transcription factors and modulate caspase-mediated cell apoptosis. CCC cells may upregulate the TFPI-2 expression to adapt to survival in the demanding environment. TFPI-2 is secreted by CCC cells and enters the systemic circulation, resulting in elevated blood levels.

DISCUSSION

Serum TFPI-2 reflects the overexpression of TFPI-2 in CCC tissues and is a potential serodiagnostic marker. Further research is needed to explore the expression, clinical significance, biological function, and potential mechanism of TFPI-2 in CCC.

Tissue factor pathway inhibitor‑2 is specifically expressed in ovarian clear cell carcinoma tissues in the nucleus, cytoplasm and extracellular matrix

Tissue factor pathway inhibitor-2 (TFPI-2) is a promising candidate as a serum biomarker of ovarian clear cell carcinoma (OCCC), a lethal histological subtype of epithelial ovarian cancer (EOC). TFPI-2 is a secreted serine protease inhibitor that suppresses cancer progression through the inhibition of matrix protease activities. Previous studies have also identified TFPI-2 in the nucleus, and a possible function of nuclear TFPI-2 as a transcriptional repressor of matrix metalloproteinase-2 (MMP-2) was recently demonstrated. We are currently establishing TFPI-2 as a serum biomarker for OCCC patients; however, TFPI-2 expression in OCCC tissues has not been previously investigated. In the present study, we examined TFPI-2 expression and its localization in 11 OCCC cell lines by western blotting and enzyme-linked immune assay. Four cell lines expressed TFPI-2 in the nucleus, cytoplasm and culture plate–attached extracellular fraction, while four other cell lines expressed TFPI-2 only in the extracellular fraction. In the remaining three cell lines, TFPI-2 was not identified in any fraction. The amount of secreted soluble TFPI-2 showed similar trends to that of the plate-attached fraction. We next investigated the expression levels and distribution of TFPI-2 in surgically resected EOC tissues by immunohistochemistry. In 52 of the 77 (67.5%) OCCC tumors, TFPI-2 expression was detected in at least one of the nuclear, cytoplasmic and extracellular matrix fractions. In contrast, we did not identify TFPI-2 in the other EOC subtypes (n=65). TFPI-2-positive expression distinguished CCC from the other EOC tissues with a sensitivity of 67.5% and specificity of 100%. Although the inherent tumor suppressor function, statistical analyses failed to demonstrate correlations between TFPI-2 expression and clinical parameters, including 5-year overall survival, except for the patient age. In conclusion, we identified TFPI-2 expression in the nucleus, cytoplasm and extracellular matrix in OCCC tissues. The high specificity of TFPI-2 may support its use for diagnosis of OCCC in combination with existing markers.

Two ways of epigenetic silencing of TFPI2 in cervical cancer

Objective

Comparison of human mRNA microarray results from tumor-associated and normal cervical fibroblasts revealed significant TFPI2 downregulation in tumor-associated fibroblasts isolated from cervical cancer, indicating that TFPI2 downregulation may play an important role in the pathogenesis of the disease. In the present work, we investigated the mechanism of TFPI2 downregulation in tumor-associated fibroblasts and tumor cells.

Methods

In vitro models of monocultures and co-cultures were established with tumor cells and fibroblasts to explore the changes of TFPI-2 expression and epigenetic modifications of the TFPI2 gene.

Results

The TFPI2 gene was hypermethylated only in tumor cells. Reduction of TFPI-2 protein levels in tumor-associated fibroblasts, although the gene was not methylated, suggested alternative regulatory mechanisms of gene expression, such as inhibition by microRNAs. The expression pattern of miR-23a, a gene thought to inhibit TFPI2 translation, showed changes strongly correlated to detected TFPI-2 protein alterations. Transfections with miR-23a mimics resulted in a decrease of TFPI-2 protein expression whereas miR-23a inhibitors increased the TFPI-2 amount. Due to downregulation of miR-23a expression by HPV in cancer cells, TFPI2 was silenced by promoter methylation. In contrary, miR-23a was active in HPV-free fibroblasts and inactivated TFPI2.

Conclusion

These results indicate dual epigenetic inhibition of TFPI2 on the transcription level by promoter methylation in cancer cells and on the translation level by miR-23a in tumor-associated fibroblasts. As a consequence, inactivation of the TFPI2 gene plays a strategic role in the progression of cervical cancer.

Increased placental expression of Placental Protein 5 (PP5) / Tissue Factor Pathway Inhibitor-2 (TFPI-2) in women with preeclampsia and HELLP syndrome: Relevance to impaired trophoblast invasion?

INTRODUCTION

Placental Protein 5 (PP5)/Tissue Factor Pathway Inhibitor-2 (TFPI-2) is an extracellular matrix-associated protein mainly expressed by the syncytiotrophoblast that may regulate trophoblast invasion. Our aim was to study placental PP5/TFPI-2 expression and its relation to placental pathology in various forms of preeclampsia and HELLP syndrome.

METHODS

Placental and maternal blood specimens were collected at the time of delivery from the same women in the following groups: 1) early controls; 2) early preeclampsia; 3) early preeclampsia with HELLP syndrome; 4) late controls; and 5) late preeclampsia. After histopathological examination, placental specimens were immunostained with polyclonal anti-PP5/TFPI-2 antibody on Western blot and tissue microarray immunohistochemistry. Placental PP5/TFPI-2 immunoscores were assessed manually and with a semi-automated method. Maternal sera were immunoassayed for PP5/TFPI-2.

RESULTS

PP5/TFPI-2 was localized to the cytoplasm of syncytiotrophoblast. Manual and semi-automated PP5/TFPI-2 immunoscores were higher in early preeclampsia with or without HELLP syndrome but not in late preeclampsia than in respective controls. In patients with preeclampsia, the correlation of placental PP5/TFPI-2 expression with maternal vascular malperfusion score of the placenta was positive while it was negative with birthweight and placental weight. Maternal serum PP5/TFPI-2 concentration was higher in early preeclampsia and it tended to be higher in early preeclampsia with HELLP syndrome than in early controls.

DISCUSSION

Our findings suggest that an increased placental PP5/TFPI-2 expression may be associated with abnormal placentation in early preeclampsia, with or without HELLP syndrome.

Bisphenol A exposure alters placentation and causes preeclampsia-like features in pregnant mice involved in reprogramming of DNA methylation of WNT2

Preeclampsia leads to adverse outcomes for pregnant women. Bisphenol A (BPA) is an environmental endocrine disruptor and has been shown to be positively associated with increased risk of preeclampsia in human studies. We investigated whether BPA exposure causes preeclampsia-like features in pregnant mice and the associated underlying mechanisms. Experiments were performed in animal models and cell cultures. In pregnant mice, BPA-exposed mice exhibited preeclampsia-like features including hypertension, disruption of the circulation, and the placental angiogenesis biomarkers fms-related tyrosine kinase 1 and placenta growth factor, and glomerular atrophy; urinary protein was not affected. These preeclampsia-like features correlated with increased retention of smooth muscle cells and reduced vessel areas at the junctional zone of the placenta. In addition, there were disrupted expression of invasion-related genes including increased tissue inhibitors of metalloproteinases, decreased metalloproteinases, and Wnt family member WNT2/β-catenin, which correlated with increased DNA methylation in its promoter region and upregulation of DNA methyltransferase (Dnmt)1. BPA exposure impeded the interaction between the human cytotrophoblast cell line, HTR-8/SVneo, and endothelium cells. BPA exposure down-regulated WNT2 expression, and elevated the DNA methylation of WNT2; these results were consistent with in vivo observations. Inhibition of DNMT in HTR-8/SVneo cells resulted in reduced DNA methylation and increased expression of WNT2. Taken together, these data demonstrate that BPA exposure alters trophoblast cell invasion and causes abnormal placental vessel remodeling, both of which lead to the development of preeclampsia-like features in pregnant mice. Our results suggest that this phenomenon involves the epigenetic reprogramming and down-regulation of WNT2 mediated by DNMT1.-Ye, Y., Tang, Y., Xiong, Y., Feng, L., Li, X. Bisphenol A exposure alters placentation and causes preeclampsia-like features in pregnant mice involved in reprogramming of DNA methylation of WNT2.

A proteomic clock of human pregnancy

BACKGROUND

Early detection of maladaptive processes underlying pregnancy-related pathologies is desirable because it will enable targeted interventions ahead of clinical manifestations. The quantitative analysis of plasma proteins features prominently among molecular approaches used to detect deviations from normal pregnancy. However, derivation of proteomic signatures sufficiently predictive of pregnancy-related outcomes has been challenging. An important obstacle hindering such efforts were limitations in assay technology, which prevented the broad examination of the plasma proteome.

OBJECTIVE

The recent availability of a highly multiplexed platform affording the simultaneous measurement of 1310 plasma proteins opens the door for a more explorative approach. The major aim of this study was to examine whether analysis of plasma collected during gestation of term pregnancy would allow identifying a set of proteins that tightly track gestational age. Establishing precisely timed plasma proteomic changes during term pregnancy is a critical step in identifying deviations from regular patterns caused by fetal and maternal maladaptations. A second aim was to gain insight into functional attributes of identified proteins and link such attributes to relevant immunological changes.

STUDY DESIGN

Pregnant women participated in this longitudinal study. In 2 subsequent sets of 21 (training cohort) and 10 (validation cohort) women, specific blood specimens were collected during the first (7-14 weeks), second (15-20 weeks), and third (24-32 weeks) trimesters and 6 weeks postpartum for analysis with a highly multiplexed aptamer-based platform. An elastic net algorithm was applied to infer a proteomic model predicting gestational age. A bootstrapping procedure and piecewise regression analysis was used to extract the minimum number of proteins required for predicting gestational age without compromising predictive power. Gene ontology analysis was applied to infer enrichment of molecular functions among proteins included in the proteomic model. Changes in abundance of proteins with such functions were linked to immune features predictive of gestational age at the time of sampling in pregnancies delivering at term.

RESULTS

An independently validated model consisting of 74 proteins strongly predicted gestational age (P = 3.8 × 10^-14, R = 0.97). The model could be reduced to 8 proteins without losing its predictive power (P = 1.7 × 10^-3, R = 0.91). The 3 top ranked proteins were glypican 3, chorionic somatomammotropin hormone, and granulins. Proteins activating the Janus kinase and signal transducer and activator of transcription pathway were enriched in the proteomic model, chorionic somatomammotropin hormone being the top-ranked protein. Abundance of chorionic somatomammotropin hormone strongly correlated with signal transducer and activator of transcription-5 signaling activity in CD4 T cells, the endogenous cell-signaling event most predictive of gestational age.

CONCLUSION

Results indicate that precisely timed changes in the plasma proteome during term pregnancy mirror a proteomic clock. Importantly, the combined use of several plasma proteins was required for accurate prediction. The exciting promise of such a clock is that deviations from its regular chronological profile may assist in the early diagnoses of pregnancy-related pathologies, and point to underlying pathophysiology. Functional analysis of the proteomic model generated the novel hypothesis that chrionic somatomammotropin hormone may critically regulate T-cell function during pregnancy.

The maternal plasma proteome changes as a function of gestational age in normal pregnancy: a longitudinal study

OBJECTIVE

Pregnancy is accompanied by dramatic physiological changes in maternal plasma proteins. Characterization of the maternal plasma proteome in normal pregnancy is an essential step for understanding changes to predict pregnancy outcome. The objective of this study was to describe maternal plasma proteins that change in abundance with advancing gestational age and determine biological processes that are perturbed in normal pregnancy.

STUDY DESIGN

A longitudinal study included 43 normal pregnancies that had a term delivery of an infant who was appropriate for gestational age without maternal or neonatal complications. For each pregnancy, 3 to 6 maternal plasma samples (median, 5) were profiled to measure the abundance of 1125 proteins using multiplex assays. Linear mixed-effects models with polynomial splines were used to model protein abundance as a function of gestational age, and the significance of the association was inferred via likelihood ratio tests. Proteins considered to be significantly changed were defined as having the following: (1) >1.5-fold change between 8 and 40 weeks of gestation; and (2) a false discovery rate-adjusted value of P < .1. Gene ontology enrichment analysis was used to identify biological processes overrepresented among the proteins that changed with advancing gestation.

RESULTS

The following results were found: (1) Ten percent (112 of 1125) of the profiled proteins changed in abundance as a function of gestational age; (2) of the 1125 proteins analyzed, glypican-3, sialic acid-binding immunoglobulin-type lectin-6, placental growth factor, C-C motif-28, carbonic anhydrase 6, prolactin, interleukin-1 receptor 4, dual-specificity mitogen-activated protein kinase 4, and pregnancy-associated plasma protein-A had more than a 5-fold change in abundance across gestation (these 9 proteins are known to be involved in a wide range of both physiological and pathological processes, such as growth regulation, embryogenesis, angiogenesis immunoregulation, inflammation etc); and (3) biological processes associated with protein changes in normal pregnancy included defense response, defense response to bacteria, proteolysis, and leukocyte migration (false discovery rate, 10%).

CONCLUSION

The plasma proteome of normal pregnancy demonstrates dramatic changes in both the magnitude of changes and the fraction of the proteins involved. Such information is important to understand the physiology of pregnancy and the development of biomarkers to differentiate normal vs abnormal pregnancy and determine the response to interventions.

Evaluation of maternal serum hypoxia inducible factor-1α, progranulin and syndecan-1 levels in pregnancies with early- and late-onset preeclampsia

OBJECTIVE

To determine the serum levels of HIF-1 α, progranulin, and syndecan-1 in preeclampsia (PE) and normal pregnancy, and to compare whether these markers demonstrate any difference between early-onset PE (EO-PE) and late-onset PE (LO-PE).

METHODS

This cross-sectional study was conducted on 27 women with EO-PE, 27 women with LO-PE, and 26 healthy normotensive pregnant controls matched for gestational age. Maternal levels of serum HIF-1 α, progranulin, and syndecan-1 were measured with the use of an enzyme-linked immunosorbent assay kit.

RESULTS

Statistical analysis revealed significant differences between the control and the PE groups in progranulin (p < .001) and syndecan-1 (p <.001) levels. There were no significant differences in the serum HIF-1 α levels between these groups (p= .069). When PE patients were evaluated by considering subgroups; statistical analysis revealed significant inter-group differences in all biomarkers. Serum progranulin levels were significantly higher in LO-PE compared with the other two groups (EO-PE versus LO-PE and LO-PE versus controls p = .000). Control group presented significantly higher syndecan-1 levels, than EO and LO-PE (p < .001). HIF-1 α levels positively correlated with progranulin levels (r = .439, p= .000).

CONCLUSIONS

Serum progranulin may have potential to be used as a biomarker for the differentiation of EO-PE and LO-PE. The co-operative action between HIF-1 α and progranulin might play a key role in the pathogenesis of LO-PE. The predominant feature of LO-PE seems to be an inflammatory process, whereas in EO-PE placentation problem seems to be the main pathology.

Impact of haemostatic mechanisms on pathophysiology of preeclampsia

Preeclampsia (PE) is disorder of new onset hypertension and proteinuria during the second half of pregnancy. There is increasing evidence to implicate placental over-expression of tissue factor and PAR-1 in the pathophysiology of PE. Excessive activation of platelets, neutrophils and the complement system may also contribute to the placental pathology and maternal endothelial responsible for the symptoms of PE. Increased knowledge in this field may identify new therapeutic strategies for the treatment of PE.

Hypomethylation of tissue factor pathway inhibitor 2 in human placenta of preeclampsia

OBJECTIVES

To investigate the expression, DNA methylation status and its regulatory mechanism of tissue factor pathway inhibitor 2 (TFPI-2) in human placenta tissues of preeclampsia (PE).

MATERIAL AND METHODS

We studied the mRNA and protein expression and the promoter methylation levels of TFPI-2 in the PE placentas compared with those in the normal pregnant (NP) women. Quantitative real-time polymerase chain reaction, immunohistochemistry, western blot, and Sequenom MassARRAY were used for placenta tissue detection.

RESULTS

The expressions of TFPI-2 mRNA and protein were significantly elevated in the PE placentas when compared with those in the NP ones (P<0.05). Hypomethylation of the TFPI-2 promoter was detected both in PE patients and NP women, with a significant decrease in PE placentas (P=0.005). The methylation level was significantly decreased at CpG_6 (-168 to -167), CpG_15 (-98 to -97) and CpG_18.19 (-68 to -65) in PE patients than that in normal placentas (P<0.05). However, the expression of DNMT-1 didn't show significant difference between the two groups (P>0.05).

CONCLUSION

Over-expression of TFPI-2 and aberrant promoter mythylation status presented in the PE placentas, suggesting that epigenetic mechanism might contribute to the pathogenesis of PE.

A potential pathophysiological role for galectins and the renin-angiotensin system in preeclampsia

This review discusses a potential role of galectins and the renin-angiotensin system (RAS) in the pathophysiology of preeclampsia (PE). Preeclampsia affects between 3 and 5 % of all pregnancies and is a heterogeneous disease, which may be caused by multiple factors. The only cure is the delivery of the placenta, which may result in a premature delivery and baby. Probably due to its heterogeneity, PE studies in human have hitherto only led to the identification of a limited number of factors involved in the pathogenesis of the disease. Animal models, particularly in mice and rats, have been used to gain further insight into the molecular pathology behind PE. In this review, we discuss the picture emerging from human and animal studies pointing to galectins and the RAS being associated with the PE syndrome and affecting a broad range of cellular signaling components. Moreover, we review the epidemiological evidence for PE increasing the risk of future cardiovascular disease later in life.

Discovery and diagnostic value of a novel oncofetal protein: glypican 3

Glypican 3 is a membrane-bound heparan sulfate proteoglycan, which has recently been identified as a marker for liver cancer and germ cell malignancies. Individuals with loss-of-function mutations for the glypican 3 gene exhibit Simpson-Golabi-Behmel syndrome, a rare X-linked overgrowth disorder. Expression of glypican 3 mRNA and protein is normally silenced in most adult organs and may reappear during malignant transformation. In the past few years, immunohistochemical and molecular characteristics of glypican 3 in hepatocellular carcinoma have been elucidated. More recently, glypican 3 has been emerging as a new diagnostic marker for germ cell tumors and especially testicular and ovarian yolk sac tumors. However, in other tumors such as renal cell carcinomas, squamous cell carcinomas, and melanomas, studies disagree on the level of glypican 3 expression. Finally, there is the controversial notion of glypican 3 as a tumor suppressor gene. In this review article, we update current knowledge on glypican 3 expression in normal and neoplastic tissues, evaluate its utility as a tumor marker in clinical practice, and explore its role as a novel oncofetal protein with clinical implications. Our focus is on the diagnostic value of glypican 3 in germ cell tumors and other neoplasms in addition to hepatocellular carcinoma. In conclusion, glypican 3 has been proven to be a useful immunohistochemical marker in distinguishing yolk sac tumors, choriocarcinomas, and Wilms tumors from other malignancies histologically mimicking these primitive tumors. Clinically, we recommend that glypican 3 be used as part of a panel of markers in subtyping testicular germ cell tumors.

Platelets contain tissue factor pathway inhibitor-2 derived from megakaryocytes and inhibits fibrinolysis

Tissue factor pathway inhibitor-2 (TFPI-2) is a homologue of TFPI-1 and contains three Kunitz-type domains and a basic C terminus region. The N-terminal domain of TFPI-2 is the only inhibitory domain, and it inhibits plasma kallikrein, factor XIa, and plasmin. However, plasma TFPI-2 levels are negligible (≤20 pM) in the context of influencing clotting or fibrinolysis. Here, we report that platelets contain significant amounts of TFPI-2 derived from megakaryocytes. We employed RT-PCR, Western blotting, immunohistochemistry, and confocal microscopy to determine that platelets, MEG-01 megakaryoblastic cells, and bone marrow megakaryocytes contain TFPI-2. ELISA data reveal that TFPI-2 binds factor V (FV) and partially B-domain-deleted FV (FV-1033) with K(d) ~9 nM and binds FVa with K(d) ~100 nM. Steady state analysis of surface plasmon resonance data reveal that TFPI-2 and TFPI-1 bind FV-1033 with K(d) ~36-48 nM and bind FVa with K(d) ~252-456 nM. Further, TFPI-1 (but not TFPI-1161) competes with TFPI-2 in binding to FV. These data indicate that the C-terminal basic region of TFPI-2 is similar to that of TFPI-1 and plays a role in binding to the FV B-domain acidic region. Using pull-down assays and Western blots, we show that TFPI-2 is associated with platelet FV/FVa. TFPI-2 (~7 nM) in plasma of women at the onset of labor is also, in part, associated with FV. Importantly, TFPI-2 in platelets and in plasma of pregnant women inhibits FXIa and tissue-type plasminogen activator-induced clot fibrinolysis. In conclusion, TFPI-2 in platelets from normal or pregnant subjects and in plasma from pregnant women binds FV/Va and regulates intrinsic coagulation and fibrinolysis.

Placental syndecan-1 and sulphated glycosaminoglycans are decreased in preeclampsia

Glycosaminoglycans are found in extracellular matrix and on the cell surface in the form of proteoglycans. There is evidence that these molecules regulate biological processes, including cell survival, migration and angiogenesis. Preeclampsia is a common pregnancy disorder associated with insufficient placental development. This study aimed to determine the concentrations of glycosaminoglycans and the proteoglycan syndecan-1 within villous trophoblast and to investigate changes associated with preeclampsia. Seventy-five placental samples collected from third trimester singleton pregnancies were divided into term placentas following labour onset, gestational age-matched placentas prior to labour onset and preterm placentas. Preterm placentas were divided into three gestational age-matched groups, spontaneous preterm labour, preterm premature rupture of membranes (PPROM) and preterm preeclampsia. Sulphated glycosaminoglycan (sGAG) concentrations in placental extracts were quantified using a modified 1,9-dimethylmethylene blue assay. Syndecan-1 expression was localised using immunohistochemistry and concentrations in placental extracts determined by immunoassay. Preterm placentas had significantly lower sGAG concentrations compared to term tissues and concentrations were significantly lower in preeclampsia compared to spontaneous preterm labour (medians 5.80 and 10.0 μg/mg protein respectively, P<0.05). Syndecan-1 expression was localised to syncytiotrophoblast and median concentrations were lower in preeclampsia compared to PPROM material (preeclampsia median = 41.7, PPROM 74.4 ng/mg tissue) but not significantly different to concentrations in spontaneous preterm labour. Multivariate analysis revealed that decreased sGAG and syndecan-1 in preeclampsia were independent of labour, gestational age and birthweight centile. These findings may provide insights into a role for these molecules in the pathophysiology of preeclampsia.

Galectin signature in normal pregnancy and preeclampsia

Members of the galectin family are expressed within the female reproductive tract and have been shown to be involved in multiple biological functions that support the progression of pregnancy. Specific expression patterns of different members of this family have been identified at the maternal decidua and on the placental side. In some cases, mechanisms by which galectins exert their functions have been delineated in adverse pregnancy outcomes. This review summarizes studies on galectins that have been documented to be important for pregnancy maintenance, either supporting the maternal adaptation to pregnancy or the placentation process. In addition, we focus our discussion on the role of galectins in preeclampsia, a specific life-threatening pregnancy disorder.

Changes of placental syndecan-1 expression in preeclampsia and HELLP syndrome

Preeclampsia is characterized by maternal systemic anti-angiogenic and pro-inflammatory states. Syndecan-1 is a cell surface proteoglycan expressed by the syncytiotrophoblast, which plays an important role in angiogenesis and resolution of inflammation. Our aim was to examine placental syndecan-1 expression in preeclampsia with or without hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome. Placentas were obtained from women in the following groups: (1) late-onset preeclampsia (n = 8); (2) early-onset preeclampsia without (n = 7) and (3) with HELLP syndrome (n = 8); (4) preterm controls (n = 5); and (5) term controls (n = 9). Tissue microarrays (TMAs) were constructed from paraffin-embedded placentas. TMA slides were immunostained for syndecan-1 and evaluated using microscopy, virtual microscopy, and semi-automated image analysis. Maternal sera from patients with preeclampsia (n = 49) and controls (n = 32) were immunoassayed for syndecan-1. BeWo cells were treated with Forskolin or Latrunculin B or kept in ischemic conditions. SDC1 expression and syndecan-1 production were investigated with qRT-PCR, confocal microscopy, and immunoassays. Syndecan-1 was localized to the syncytiotrophoblast apical membrane in normal placentas. Syndecan-1 immunoscores were higher in late-onset preeclampsia (p = 0.0001) and early-onset preeclampsia with or without HELLP syndrome (p = 0.02 for both) than in controls. Maternal serum syndecan-1 concentration was lower in preeclampsia (median, 673 ng/ml; interquartile range, 459-1,161 ng/ml) than in controls (1,158 ng/ml; 622-1,480 ng/ml). SDC1 expression and syndecan-1 immunostainings in BeWo cells and syndecan-1 concentrations in supernatants increased during cell differentiation. Disruption of the actin cytoskeleton with Latrunculin B decreased syndecan-1 release, while ischemic conditions increased it. Syncytiotrophoblastic syndecan-1 expression depends on the differentiation of villous trophoblasts, and trophoblastic syndecan-1 release is decreased in preeclampsia and HELLP syndrome. This phenomenon may be related to the disturbed syncytiotrophoblastic cortical actin cytoskeleton and associated with maternal anti-angiogenic and pro-inflammatory states in these syndromes.

Distribution of sugar residues in human placentas from pregnancies complicated by hypertensive disorders

The aim of the study was to investigate the content and distribution of sugar residues in placentas from pregnancies complicated by hypertensive disorders. Placentas from women with uncomplicated pregnancies (group 1), pregnancies complicated by gestational hypertension (group 2), pregnancies complicated by pre-eclampsia (group 3), pregnancies complicated by pre-eclampsia with HELLP syndrome (hemolysis, elevated liver enzymes and low platelets) (group 4) were collected. Lectins: ConA, WGA, PNA, SBA, DBA, UEA I, GNA, DSA, MAA, SNA, in combination with chemical and enzymatic treatments, were used. Data showed a decrease and/or lack of α-d-mannose, α-d-glucose and d-galactose-(β1-4)-N-acetyl-d-glucosamine in placentas from pre-eclampsia and pre-eclampsia with HELLP syndrome compared with control and hypertension cases. N-acetyl-d-galactosamine appeared and/or increased in placentas from hypertensive disorders. A different distribution of various types of sialic acid was observed in placentas from hypertensive disorders compared with the controls. In particular, placentas from pre-eclampsia, with and without HELLP syndrome, lacked the acetylated sialic acid side-chain. These findings demonstrate various alterations of the carbohydrate metabolism in the placentas from pregnancies complicated by different types of hypertensive disorders. This indicates correlation with the placental morpho-functional changes characteristic of these complications and with the degree of clinical severity.

Expression of glypican 3 in placental site trophoblastic tumor

Background

Glypican-3 (GPC3) is a membrane-bound heparan sulfate proteoglycan that functions in embryonic cell growth and differentiation and is highly expressed in the placenta. GPC3 is mutated in Simpson-Golabi-Behmel syndrome, which is characterized by tissue overgrowth and an increased risk of embryonal malignancies. GPC3 has also been implicated in sporadic cancer, particularly hepatocellular carcinoma, for which it has been shown to be a useful diagnostic marker. Although GPC3 expression has been studied in non-neoplastic placental tissue, its presence in gestational trophoblastic diseases has not been previously explored. The purpose of this study was to investigate the immunohistochemical expression of GPC3 in placental site trophoblastic tumor (PSTT), a very rare gestational trophoblastic neoplasm which may be morphologically confused with non-trophoblastic tumors, and to assess its possible utility as a diagnostic marker.

Methods

Fifteen cases of PSTT, as well as samples from placental site nodule (PSN) (n = 2), leiomyosarcoma (n = 1), leiomyoma (n = 1), invasive cervical squamous cell carcinoma (n = 7) and endometrial adenocarcinoma (n = 11) were examined. Immunoreactivity was semi-quantitatively evaluated as negative (0, < 5% of cells stained), focally positive (1+, 5-10% of cells stained), positive (2+, 11-50% of cells stained) or diffusely positive (3+, > 50% of cells stained). Staining intensity for each subtype was graded from 0 to 3 and a mean intensity was calculated.

Results

Eighty percent of PSTT (12/15) were immunoreactive for GPC3 (0, 20; 1+, 20%; 2+, 40%; 3+, 20%) with a mean intensity of 1.3. Stronger, predominately cytoplasmic staining was seen in larger multi- and mononucleated cells with smaller mononucleate cells showing weak muddy cytoplasmic staining. Both PSN cases were positive (1+, 50%; 2+, 50%) and two of nine invasive cervical squamous cell carcinomas showed staining (0, 57%; 1+, 29%; 2+, 14%), predominately in a basal distribution. Other uterine tumors and non-neoplastic tissues were negative.

Conclusions

Identification of GPC3 in PSTT and PSN is consistent with the derivation of these lesions from intermediate trophoblasts, which have been described to express GPC3. GPC3 may be a useful adjunct immunohistochemical marker in differentiating PSTT from non-trophoblastic tumors.

Changes of plasma and placental tissue factor pathway inhibitor-2 in women with preeclampsia and normal pregnancy

OBJECTIVES

To investigate the maternal and fetal plasma changes of tissue factor pathway inibitor-2 (TFPI-2) and its placental expression in women with normal pregnancy and preeclampsia.

MATERIAL AND METHODS

We assessed the plasma TFPI-2 level in non-pregnant, normal pregnant and postpartum women, detected fetal plasma level and expression in placenta, and compared the changes in women with preeclampsia. Time-resolved fluoroimmunoassay and immunohistochemistry were used for plasma and placenta tissue detection, respectively.

RESULTS

Maternal plasma levels of TFPI-2 in normal pregnant women at 13weeks of gestation increased 9.3 times as compared with healthy non-pregnant women (149.3+/-17.1 versus 16.0+/-3.6ng/ml)reached a maximum level ( 282.6+/-17.1ng/ml) at 39weeks of gestation, and dramatically decreased to nearly a non-pregnant level on the first day of postpartum (32.3+/-7.1ng/ml); similar change was found in the placental expression. Fetal plasma TFPI-2 was significantly lower than the maternal level at delivery. The maternal plasma TFPI-2 in preeclampsia was significantly lower compared with that in normal pregnancy, coupled with significantly higher placental expression.

CONCLUSIONS

Placenta may be the main site of the high level of TFPI-2 production in maternal circulation, and the dramatic changes in preeclampsia provide a clue to elucidate its pathogenesis.

The relationship between plasma and placental tissue factor, and tissue factor pathway inhibitors in severe pre-eclampsia patients

OBJECTIVE

To investigate the mechanism underlying the hypercoagulable state in severe pre-eclampsia.

METHODS

Plasma tissue factor (TF) and tissue factor pathway inhibitor (TFPI) expression from pre-eclampsia patients and healthy pregnant controls were determined by ELISA. Placental TF and TFPI gene and protein expression were detected by quantitative RT-PCR, immunohistochemistry, and Western analysis.

RESULTS

The plasma TF level in the pre-eclampsia group was significantly higher than the control group (p<0.01), and surprisingly, the plasma TFPI-1 and TFPI-2 in the pre-eclampsia group were significantly lower (p<0.01). Placental TF gene and protein expression levels in the pre-eclampsia group was significantly higher than the control group, while TFPI-1 and TFPI-2 levels were significantly lower (p<0.05). Lastly, a significant correlation was found between plasma and placental TF protein levels in the pre-eclampsia group (p<0.01).

CONCLUSION

Higher expression and/or release of TF from the placenta may contribute towards a pathological hypercoagulable state in pre-eclampsia patients.

Markers of haemostasis and angiogenesis in placentae from gestational vascular complications: impairment of mechanisms involved in maintaining intervillous blood flow

INTRODUCTION

Preeclampsia (PE) and fetal growth restriction (FGR) are multifactorial diseases, whose pathogenesis is largely unknown. A significant relationship between haemostasis and angiogenesis in placentae from uneventful pregnancies was previously shown.

MATERIALS AND METHODS

RNA expression of haemostasis (TF, TFPI, TFPI-2, PAI-2, Anx V, TM) and angiogenesis (Ang-1, Ang-2, PlGF, VEGF) markers in placentae from PE (n=12), PE+FGR (n=17) and FGR (n=20) in respect of placentae from uncomplicated pregnancies (n=21) were investigated.

RESULTS

Placentae from complicated pregnancies showed a significant lower expression (p<or=0.05 Mann-Whitney U test) of TF, TFPI, TFPI-2, Anx V, PAI-2 than those from in uncomplicated ones. VEGF and PlGF were not different in the considered groups; Ang-1 and Ang-2 were significantly higher (p<or=0.05 Mann-Whitney U test) in the PE group. Correlations between factors involved in haemostasis and those involved in angiogenesis, observed in placentae from uneventful pregnancies are lacking in those from complicated ones.

CONCLUSIONS

Haemostasis factors are reduced in placentae from complicated pregnancies. The relationship between haemostasis and angiogenesis observed in uncomplicated pregnancies is impaired in PE and FGR.

A link between a hemostatic disorder and preterm PROM: a role for tissue factor and tissue factor pathway inhibitor

OBJECTIVE

Vaginal bleeding is a risk factor for preterm PROM (PPROM). A disorder of decidual hemostasis has been implicated in the genesis of PROM. Indeed, excessive thrombin generation has been demonstrated in PPROM both before and at the time of diagnosis. Decidua is a potent source of tissue factor (TF), the most powerful natural pro-coagulant. A decidual hemostatic disorder may link vaginal bleeding, PPROM and placental abruption. This study was conducted to determine the behaviour of maternal TF and its natural inhibitor, the tissue factor pathway inhibitor (TFPI) in PPROM.

METHODS

This cross-sectional study included women with PPROM (n = 123) and women with normal pregnancies (n = 86). Plasma concentrations of TF and TFPI were measured by a sensitive immunoassay. Non-parametric statistics were used for analysis.

RESULTS

(1) The median maternal plasma TF concentration was significantly higher in patients with PPROM than in women with normal pregnancies (median: 369.5 pg/mL; range: 3.27-2551 pg/mL vs. median: 291.5 pg/mL; range: 6.3-2662.2 pg/mL respectively, p = 0.001); (2) the median maternal TFPI plasma concentration was significantly lower in patients with PPROM than in women with normal pregnancies (median: 58.7 ng/mL; range: 26.3-116 ng/mL vs. median: 66.1 ng/mL; range: 14.3-86.5 ng/mL respectively, p = 0.019); (3) there was no correlation between the plasma concentration of TF and TFPI and the gestational age at sample collection; and (4) among patients with PPROM there was no association between the presence of intra-amniotic infection or inflammation and median plasma concentrations of TF and TFPI.

CONCLUSIONS

(1) Patients with PPROM have a higher median plasma concentration of TF and a lower median plasma concentration of TFPI than women with normal pregnancies. (2) These findings suggest that PPROM is associated with specific changes in the hemostatic/coagulation system.

Tissue factor and its natural inhibitor in pre-eclampsia and SGA

OBJECTIVE

Tissue factor (TF), the major activator of the extrinsic pathway of coagulation, is abundant in the placenta and decidua. The aim of this study was to determine the maternal plasma concentrations of TF and its primary inhibitor, tissue factor pathway inhibitor (TFPI), in women who delivered small for gestational age (SGA) neonates, and in pre-eclampsia.

STUDY DESIGN

A cross-sectional study included the following groups: 1) women with normal pregnancies (n = 86); 2) patients who delivered SGA neonates (n = 61) and 3) women with pre-eclampsia (n = 133). Maternal plasma concentrations of TF and TFPI were measured by a sensitive immunoassay. Non-parametric statistics were used for analysis.

RESULTS

1) Women with pre-eclampsia had a significantly higher median plasma concentration of TF than patients with a normal pregnancy (median: 1187 pg/mL; range: 69-11675 vs. median: 291.5 pg/mL; range: 6.3-2662.2; p < 0.0001, respectively); 2) Similarly, TFPI concentrations were higher in pre-eclampsia than in normal pregnancy (median: 87.5 ng/mL; range 25.4-165.1 vs. median: 66.1 ng/mL; range: 14.3-86.5; p < 0.0001, respectively); 3) Surprisingly, mothers with SGA neonates had a lower median maternal plasma concentration of TF (median: 112.2 pg/mL; range: 25.6-1225.3) than women with a normal pregnancy (p < 0.0001).

CONCLUSION

1) Maternal plasma concentrations of TF in patients with pre-eclampsia, but not in those who delivered an SGA neonate, were higher than in women with normal pregnancies; 2) Although the role of immunoreactive plasma TF in coagulation remains controversial, our observations suggest that changes are present in the context of complications of pregnancy.

Placental protein 13 (galectin-13) has decreased placental expression but increased shedding and maternal serum concentrations in patients presenting with preterm pre-eclampsia and HELLP syndrome

Placental protein 13 (PP13) is a galectin expressed by the syncytiotrophoblast. Women who subsequently develop preterm pre-eclampsia have low first trimester maternal serum PP13 concentrations. This study revealed that third trimester maternal serum PP13 concentration increased with gestational age in normal pregnancies (p < 0.0001), and it was significantly higher in women presenting with preterm pre-eclampsia (p = 0.02) and hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome (p = 0.01) than in preterm controls. Conversely, placental PP13 mRNA (p = 0.03) and protein, as well as cytoplasmic PP13 staining of the syncytiotrophoblast (p < 0.05) was decreased in these pathological pregnancies compared to controls. No differences in placental expression and serum concentrations of PP13 were found at term between patients with pre-eclampsia and control women. In contrast, the immunoreactivity of the syncytiotrophoblast microvillous membrane was stronger in both term and preterm pre-eclampsia and HELLP syndrome than in controls. Moreover, large syncytial cytoplasm protrusions, membrane blebs and shed microparticles strongly stained for PP13 in pre-eclampsia and HELLP syndrome. In conclusion, parallel to its decreased placental expression, an augmented membrane shedding of PP13 contributes to the increased third trimester maternal serum PP13 concentrations in women with preterm pre-eclampsia and HELLP syndrome.

Silencing of tissue factor pathway inhibitor-2 gene in malignant melanomas

To identify tumor-suppressor genes inactivated by aberrant methylation of promoter CpG islands (CGIs) in human malignant melanomas, genes upregulated by treatment of cells with a demethylating agent, 5-aza-2'-deoxycytidine (5-aza-dC), were searched for using oligonucleotide microarrays in melanoma cell lines, HMV-I, MeWo and WM-115. Seventy-nine known genes with CGIs were identified as being upregulated (>or=16-fold), and 18 of them had methylation of their putative promoter CGIs in 1 or more of 8 melanoma cell lines. Among the 18 genes, TFPI-2, which is involved in repression of the invasive potential of malignant melanomas, was further analyzed. Its expression was repressed in a melanoma cell line with its complete methylation, and was restored by 5-aza-dC treatment. It was unmethylated in cultured neonatal normal epidermal melanocyte, and was induced by ultraviolet B. In surgical melanoma specimens, TFPI-2 methylation was detected in 5 of 17 metastatic site specimens (29%), while it was not detected in 20 primary site specimens (0%) (p=0.009). By immunohistochemistry, the 5 specimens with promoter methylation lacked immunoreactivity for TFPI-2. The results showed that TFPI-2 is silenced in human malignant melanomas by methylation of its promoter CGI and suggested that its silencing is involved in melanoma metastasis.