Trophoblastic vasculogenic mimicry in gestational choriocarcinoma

Intraplacental Gestational Neoplasms: A Review of Clinically Relevant Diagnostically Challenging Lesions

CONTEXT.—

Case studies reporting intraplacental choriocarcinoma (IPC) and intraplacental "chorangiocarcinoma" have recently increased, with IPC also represented in molecular analyses of gestational trophoblastic neoplasms.

OBJECTIVE.—

To provide an overview of 2 intraplacental neoplastic lesions that can have a significant impact on both mother and fetus/infant, focusing on diagnostic characteristics, and ancillary and molecular tools that support diagnosis, determine prognosis, and further elucidate the nature of these lesions.

DATA SOURCES.—

Data were compiled from a PubMed literature review that included diagnostic and additional keywords within the scope of study for gestational choriocarcinoma in general. Illustrative cases were retrieved from the pathology archives at Michigan Medicine, including the consultation files of the author.

CONCLUSIONS.—

Intraplacental gestational tumors exist along the spectrum of benign (chorangioma) to aggressive malignant (choriocarcinoma) neoplasms with a high potential for metastasis. Although most gestational choriocarcinomas follow complete hydatidiform mole, 20% to 25% occur in association with normal intrauterine gestations, including rare cases in which they are detected within the placenta (IPC). IPCs range from asymptomatic to widely metastatic, with metastases possible even when only microscopic IPCs are present. A second, even less common lesion, variably called "chorangiocarcinoma" and chorangioma with atypical trophoblast proliferation, is also reviewed. The incidence of these lesions is likely to be underestimated. Heightened suspicion and more liberal placental sampling, particularly when specific clinical features are present, may result in higher detection. Enhanced detection to provide the earliest intervention for both mother and infant may improve prognosis, particularly for asymptomatic disease that may later present with metastasis.

Platelet-Based Nanoparticles with Stimuli-Responsive for Anti-Tumor Therapy

In addition to hemostasis and coagulation, years of studies have proved that platelets are involved in the whole process of tumor progression, including tumor invasion, intravasation, extravasation, and so on. It means that this property of platelets can be used in anti-tumor therapy. However, traditional platelet-based antitumor drugs often cause autologous platelet damage due to lack of targeting, resulting in serious side effects. Therefore, the researchers designed a variety of anti-tumor drug delivery systems based on platelets by targeting platelets or platelet membrane coating. The drug delivery systems have special response modes, which is crucial in the design of nanoparticles. These modes enhance the targeting and improve the anti-tumor effect. Here, we present a review of recent discoveries in the field of the crosstalk between platelets and tumors and the progress of platelet-based anti-tumor nanoparticles.

Radiation Therapy for Gestational Trophoblastic Neoplasia: Forward-Looking Lessons Learnt

Gestational trophoblastic neoplasia (GTN) includes several rare malignant diseases occurring after pregnancy: invasive moles, choriocarcinoma, placental site trophoblastic tumours, and epithelioid trophoblastic tumours. Multidisciplinary protocols including multi-agent chemotherapy, surgery, and occasionally radiotherapy achieve good outcomes for some high-risk metastatic patients. In this narrative review of the published studies on the topic, we have tried to identify the role of radiotherapy. The available studies are mainly small, old, and retrospective, with incomplete data regarding radiotherapy protocols delivering low doses (which can make this disease appear radioresistant in some cases despite high response rates with palliative doses) to wide fields (whole-brain, whole-liver, etc.), which can increase toxicity. Studies considering modern techniques are needed to overcome these limitations and determine the full potential of radiotherapy beyond its antihemorrhagic and palliative roles.

Pathological angiogenesis: mechanisms and therapeutic strategies

In multicellular organisms, angiogenesis, the formation of new blood vessels from pre-existing ones, is an essential process for growth and development. Different mechanisms such as vasculogenesis, sprouting, intussusceptive, and coalescent angiogenesis, as well as vessel co-option, vasculogenic mimicry and lymphangiogenesis, underlie the formation of new vasculature. In many pathological conditions, such as cancer, atherosclerosis, arthritis, psoriasis, endometriosis, obesity and SARS-CoV-2(COVID-19), developmental angiogenic processes are recapitulated, but are often done so without the normal feedback mechanisms that regulate the ordinary spatial and temporal patterns of blood vessel formation. Thus, pathological angiogenesis presents new challenges yet new opportunities for the design of vascular-directed therapies. Here, we provide an overview of recent insights into blood vessel development and highlight novel therapeutic strategies that promote or inhibit the process of angiogenesis to stabilize, reverse, or even halt disease progression. In our review, we will also explore several additional aspects (the angiogenic switch, hypoxia, angiocrine signals, endothelial plasticity, vessel normalization, and endothelial cell anergy) that operate in parallel to canonical angiogenesis mechanisms and speculate how these processes may also be targeted with anti-angiogenic or vascular-directed therapies.

Forskolin promotes vasculogenic mimicry and invasion via Notch‑1‑activated epithelial‑to‑mesenchymal transition in syncytiolization of trophoblast cells in choriocarcinoma

Choriocarcinoma (CC) is characterized by earlier blood metastasis compared with other female genital tumors and a high incidence of massive hemorrhage. Vasculogenic mimicry (VM) is highly associated with metastasis, and syncytiotrophoblast is involved in the formation of VM in CC. Forskolin is a typical activator of the cAMP pathway, which is involved in the syncytiolization of trophoblastic cells. In the present study, to determine the effects and mechanism of forskolin on cell invasion and VM during syncytiolization in vitro and in vivo, JEG-3 and JAR cell lines were treated with 100 µM forskolin for 48 h, and wound healing and invasion assays were used to verify cell migratory and invasive capacities. A 3D culture and tube formation assays were established to detect VM. Variation of morphology and markers of the epithelial-to-mesenchymal transition (EMT) were assessed, and the role of the Notch signaling pathway was investigated in CC cells treated with forskolin. The results of the present study demonstrated that 100 µM forskolin induced syncytiolization of trophoblastic cells and enhanced the migratory and invasive abilities of JEG-3 and JAR cell lines. In addition, the capacity of VM was significantly increased, whereas tube formation ability was decreased by forskolin in vitro and in vivo compared with the respective control groups. The cellular morphology exhibited EMT during the syncytiolization process, which was further supported by the changes in EMT marker expression, including downregulation of E-cadherin and cytokeratin and upregulation of N-cadherin, vimentin and zinc finger E-box-binding homeobox 1. The Notch-1 signaling pathway was activated to induce EMT in forskolin-induced VM process in CC cells, and VM and EMT could be reversed by using the γ-secretase inhibitor DAPT to block the Notch-1 pathway. Overall, the results of the present study demonstrated that forskolin enhanced the capacity of VM formation and metastasis through Notch-1-activated EMT in the syncytiolization of trophoblastic cells.

Overview of advances in vasculogenic mimicry - a potential target for tumor therapy

Vasculogenic mimicry (VM) describes the process utilized by highly aggressive cancer cells to generate vascular-like structures without the presence of endothelial cells. VM has been vividly described in various tumors and participates in cancer progression dissemination and metastasis. Diverse molecular mechanisms and signaling pathways are involved in VM formation. Furthermore, the patterning characteristics of VM, detected with molecular imaging, are being investigated for use as a tool to aid clinical practice. This review explores the most recent studies investigating the role of VM in tumor induction. Indeed, the recognition of these advances will increasingly affect the development of novel therapeutic target strategies for VM in human cancer.

Knockdown of Heparanase Suppresses Invasion of Human Trophoblasts by Activating p38 MAPK Signaling Pathway

Preeclampsia is a pregnancy-related disease with increasing maternal and perinatal morbidity and mortality worldwide. Defective trophoblast invasion is considered to be a major factor in the pathophysiological mechanism of preeclampsia. Heparanase, the only endo-β-glucuronidase in mammalian cells, has been shown to be abnormally expressed in the placenta of preeclampsia patients in our previous study. The biological role and potential mechanism of heparanase in trophoblasts remain unclear. In the present study, stably transfected HTR8/SVneo cell lines with heparanase overexpression or knockdown were constructed. The effect of heparanase on cellular proliferation, apoptosis, invasion, tube formation, and potential pathways in trophoblasts was explored. Our results showed that overexpression of heparanase promoted proliferation and invasion. Knockdown of heparanase suppressed proliferation, invasion, and tube formation but induced apoptosis. These findings reveal that downregulation of heparanase may contribute to defective placentation and plays a crucial role in the pathogenesis of preeclampsia. Furthermore, increased activation of p38 MAPK in heparanase-knockdown HTR8/SVneo cell was shown by MAPK pathway phosphorylation array and Western blotting assay. After pretreatment with 3 specific p38 MAPK inhibitors (BMS582949, SB203580, or BIRB796), inadequate invasion in heparanase-knockdown HTR8/SVneo cell was rescued. That indicates that knockdown of heparanase decreases HTR8/SVneo cell invasion through excessive activation of the p38 MAPK signaling pathway. Our study suggests that heparanase can be a potential predictive biomarker for preeclampsia at an early stage of pregnancy and represents a promising therapeutic target for the treatment of preeclampsia.

Antagonism of EG-VEGF Receptors as Targeted Therapy for Choriocarcinoma Progression In Vitro and In Vivo

Purpose: Choriocarcinoma (CC) is the most malignant gestational trophoblastic disease that often develops from complete hydatidiform moles (CHM). Neither the mechanism of CC development nor its progression is yet characterized. We recently identified endocrine gland-derived vascular endothelial growth factor (EG-VEGF) as a novel key placental growth factor that controls trophoblast proliferation and invasion. EG-VEGF acts via two receptors, PROKR1 and PROKR2. Here, we demonstrate that EG-VEGF receptors can be targeted for CC therapy.Experimental Design: Three approaches were used: (i) a clinical investigation comparing circulating EG-VEGF in control (n = 20) and in distinctive CHM (n = 38) and CC (n = 9) cohorts, (ii) an in vitro study investigating EG-VEGF effects on the CC cell line JEG3, and (iii) an in vivo study including the development of a novel CC mouse model, through a direct injection of JEG3-luciferase into the placenta of gravid SCID-mice.Results: Both placental and circulating EG-VEGF levels were increased in CHM and CC (×5) patients. EG-VEGF increased JEG3 proliferation, migration, and invasion in two-dimensional (2D) and three-dimensional (3D) culture systems. JEG3 injection in the placenta caused CC development with large metastases compared with their injection into the uterine horn. Treatment of the animal model with EG-VEGF receptor's antagonists significantly reduced tumor development and progression and preserved pregnancy. Antibody-array and immunohistological analyses further deciphered the mechanism of the antagonist's actions.Conclusions: Our work describes a novel preclinical animal model of CC and presents evidence that EG-VEGF receptors can be targeted for CC therapy. This may provide safe and less toxic therapeutic options compared with the currently used multi-agent chemotherapies. Clin Cancer Res; 23(22); 7130-40. ©2017 AACR.

Effects of HCG on human epithelial ovarian cancer vasculogenic mimicry formation in vivo

Ovarian cancer is the leading cause of mortality due to gynecological malignancy, and vasculogenic mimicry (VM) formation is correlated with poor prognosis. In a previous study, the present authors observed that human chorionic gonadotropin (HCG) could promote VM formation in three-dimensional OVCAR-3 cell cultures. In order to investigate whether HCG could promote VM formation in ovarian cancer in vivo, the role of OVCAR-3 cells overexpressing or depleted of chorionic gonadotropin, beta polypeptide 5 (CGB5, which is the fifth subunit of β-HCG and was identified as the key part of HCG) were injected into nude mice in the present study, while BeWo cells were used as a positive control. The results demonstrated that overexpressed CGB5 promoted xenografts tumor formation in nude mice, and the results of hematoxylin and eosin and cluster of differentiation (CD)34-periodic acid-Schiff dual staining revealed that CGB5 promoted VM formation. Furthermore, reverse transcription-polymerase chain reaction and immunochemistry staining demonstrated that the expression of the vascular markers CD31, vascular endothelial growth factor and factor VIII was also upregulated in the CGB5-overexpressing xenografts tumors. In addition, the expression of luteinizing hormone receptor (LHR), the receptor of CGB5, was increased in CGB5-overexpressing cells. In conclusion, CGB5 may promote tumor growth and VM formation via activation of the LHR signal transduction pathway, which may support a novel strategy for ovarian cancer therapy.

An HCG-rich microenvironment contributes to ovarian cancer cell differentiation into endothelioid cells in a three-dimensional culture system

We investigated the expression of human chorionic gonadotropin (HCG) and its effects on vasculogenic mimicry (VM) formation in ovarian cancer cells under normoxic and hypoxic conditions in three-dimensional matrices preconditioned by an endothelial-trophoblast cell co-culture system. The co-culture model was established using human umbilical vein endothelial cells (HUVECs) and HTR-8 trophoblast cells in a three-dimensional culture system. The co-cultured cells were removed with NH4OH, and ovarian cancer cells were implanted into the preconditioned matrix. VM was identified morphologically and by detecting vascular markers expressed by cancer cells. The specificity of the effects of exogenous HCG in the microenvironment was assessed by inhibition with a neutralizing anti-HCG antibody. HCG siRNA was used to knock down endogenous HCG expression in OVCAR-3 ovarian cancer cells. HTR-8 cells 'fingerprinted' HUVECs to form capillary-like tube structures in co-cultures. In the preconditioned HCG-rich microenvironment, the number of vessel-like network structures formed by HCG receptor-positive OVCAR-3 cells and the expression levels of CD31, VEGF and factor VIII were significantly increased. The preconditioned HCG-rich microenvironment significantly increased the expression of hypoxia inducible factor-1α (HIF‑1α) and VM formation in OVCAR-3 cells under hypoxic conditions. Treatment with a neutralizing anti-HCG antibody but not HCG siRNA significantly inhibited the formation of vessel-like network structures. HCG in the microenvironment contributes to OVCAR-3 differentiation into endothelioid cells in three-dimensional matrices preconditioned with an endothelial-trophoblast cell co-culture system. HCG may synergistically enhance hypoxia-induced vascular markers and HIF-1α expression. These findings would provide perspectives on new therapeutic targets for ovarian cancer.

Lymphatic endothelial cancerization in papillary thyroid carcinoma: hidden evidence of lymphatic invasion

We hypothesize that cystic structures in metastatic papillary thyroid carcinoma (PTC) develop along the framework of lymphatic channels. To investigate this phenomenon, different categories of PTC were immunostained for D2-40 and TTF1. In this study, reactivity for D2-40 was considered as positive when there is membranous staining as often seen in lymphatic endothelial cells. Thirty cases of PTC with lymph node metastasis or with potential for lymphatic invasion and 20 cases metastatic PTC in lymph nodes were reviewed and found to show double/mosaic immunoreactivity for TTF1/D2-40 in 40-100% of cases. PTC metastasis in lymph nodes with cysts and some branching lymphatic-like channels lined by follicular cells with or without nuclear features of PTC were diffusely reactive to TTF1, and focally to D2-40. For primary and metastatic PTC, focal membranous D2-40 reactivity was also demonstrated in cysts or cleft linings. For25 thyroid neoplasms with no known potential for lymphatic invasion, there was no such immunoreactivity. The mosaic or double immunoreactivity for TTF1/D2-40 suggests lymphatic cancerization and possible endothelial mimicry of follicular cells. Mosaic/double immunoreactivity is helpful to detect the hidden pattern of lymphatic invasion masquerading as 'benign-appearing' follicles and supports our hypothesis of malignant cells developing along the lymphatic framework.

Immunohistological Description of Nongestational Ovarian Choriocarcinoma in Two Female Mice With Conditional Loss of Trp53 Driven by the Tie2 Promoter

Nongestational ovarian choriocarcinoma (NGCO) is a tumor of germ cell origin seldom described in nonhuman species. Few spontaneous cases are reported in macaques and mice, with the B6C3F1 strain overrepresented. This report describes 2 cases of ovarian choriocarcinoma in nulliparous female mice with conditional loss of Trp53 under the Tie2 promoter. The mouse line was maintained on a mixed genetic background including Crl: CD1(ICR) and 129X1/SvJ strains. In both cases, affected ovary was partially replaced by blood-filled lacunae lined by neoplastic trophoblast-like giant cells. Immunohistochemically, neoplastic cells expressed folate-binding protein and prolactin and were invariably negative for p53. To the authors’ knowledge, this is the first report characterizing this entity in a genetically engineered mouse (GEM) line. Considering that germ cells (the cell population from which NGCO originates) constitutively express Tie2 receptor, it can be speculated that Tie2-driven deletion of Trp53 may have played a role in the development of these tumors.

Tumor cells forming sinusoids connected to vasculature are involved in hemorrhage of pineal choriocarcinoma

Intratumor hemorrhage is a poor prognostic factor in pineal choriocarcinoma (PCCC). The aim of this study was to understand the relationship of tumor cells to the blood vessels to gain insights into the formation of intratumor hemorrhage in PCCC. The clinical data indicated that total tumor removal by surgical procedures followed immediately by radiotherapy and chemotherapy improved the prognosis in PCCC. The PCCC tissues removed from the patients were examined by histology and immunohistochemistry. Hematoxylin and eosin staining showed that the tumor stroma mainly consists of hemorrhagic tissues with tumor cells scattered inside. The pattern of distribution suggests that the tumor cells were possibly flushed and compressed by the bleeding. The tumor cells tended to form sinusoids that lacked CD34, but laminin expression provided evidence of vasculogenic mimicry. Interestingly, CD34-positive blood vessels were found connected to these sinusoids, suggesting that blood may flow from the tumor vasculature to the sinusoids. This may subsequently cause the enlargement of the sinusoids, blood clotting, the widening of the blood lakes, and eventually extensive hemorrhagic necrosis. Our study identified the key features of the PCCC vasculature. The findings add to the previous understanding of the formation of vascular channels, blood lakes, and extensive hemorrhagic necrosis. The intimate connections between the tumor-formed sinusoids and the blood vessels might be a major cause of severe hemorrhage in PCCC. The new information may be useful for the development of treatment strategies for managing PCCC.

Development of the hemochorial maternal vascular spaces in the placenta through endothelial and vasculogenic mimicry

The maternal vasculature within the placenta in primates and rodents is unique because it is lined by fetal cells of the trophoblast lineage and not by maternal endothelial cells. In addition to trophoblast cells that invade the uterine spiral arteries that bring blood into the placenta, other trophoblast subtypes sit at different levels of the vascular space. In mice, at least five distinct subtypes of trophoblast cells have been identified which engage maternal endothelial cells on the arterial and venous frontiers of the placenta, but which also form the channel-like spaces within it through a process analogous to formation of blood vessels (vasculogenic mimicry). These cells are all large, post-mitotic trophoblast giant cells. In addition to assuming endothelial cell-like characteristics (endothelial mimicry), they produce dozens of different hormones that are thought to regulate local and systemic maternal adaptations to pregnancy. Recent work has identified distinct molecular pathways in mice that regulate the morphogenesis of trophoblast cells on the arterial and venous sides of the vascular circuit that may be analogous to specification of arterial and venous endothelial cells.

Choriocarcinoma-like tumor in a potbellied pig (Sus scrofa)

A uterine tumor, with histological and immunohistochemical features consistent with those of human choriocarcinoma, was identified in a 10-year-old unmated female pot-bellied pig ( Sus scrofa). The tumor showed biphasic proliferation of cytotrophoblast-like cells and syncytiotrophoblast-like cells. Immunohistochemically, the syncytiotrophoblast-like cells were positive for human chorionic gonadotropin, and both types of cells were positive for cytokeratin and negative for vimentin, octamer-binding transcription factor 4, and α-fetoprotein. Because syncytiotrophoblasts are absent in the normal porcine placenta, the tumor was diagnosed as a choriocarcinoma-like tumor.

Molecular genetic analysis of nongestational choriocarcinoma in a postmenopausal woman: a case report and literature review

Choriocarcinoma is a highly malignant tumor of trophoblastic origin. Most cases occur in association with preceding gestational events. However, on very rare occasions, nongestational choriocarcinoma arises from germ cell or trophoblastic differentiation in different types of carcinoma. This article reports the case of a 58-year-old woman with primary nongestational choriocarcinoma of the uterus that developed 19 years after her final pregnancy and 4 years after menopause. A total abdominal hysterectomy and bilateral salpingo-oophorectomy was performed. Histopathological examination showed choriocarcinoma of the uterus without components of other germ cell tumors. Karyotype analysis of the tumor cells demonstrated XX. We confirmed its nongestational origin by DNA polymorphism analysis at 15 short tandem repeat loci. After surgery, the patient was given four courses of combination chemotherapy. She is still alive and there has been no evidence of recurrence 3 years after surgery.

Vasculogenic mimicry and its clinical significance in medulloblastoma

Vasculogenic mimicry (VM), a process involving the formation of a tubular structure by highly invasive and genetically dysregulated tumor cells, can supplement the function of blood vessels to transport nutrients and oxygen to maintain the growth of tumor cells in many malignant tumors. We aimed to explore the existence of VM and its clinical significance in medulloblastoma in this study. VM was identified in 9 out of 41 (22%) medulloblastoma tissues. Immunohistochemical studies revealed that the presence of VM was associated with the expression of MMP-2, MMP-14, EphA2 and laminin 5γ2. Tumor tissues with VM were associated with lower microvessel density (MVD), which was indirect evidence of the blood supply function of VM. Survival analysis and log-rank tests showed that patients with VM had shorter overall survival time than those without VM. Multivariate analysis and the Cox proportional hazards model identified VM as independent prognostic factor for overall survival. Our results confirmed the existence of VM for the first time and revealed that VM is a strong independent prognostic factor for survival in patients with medulloblastoma.

Uterine artery pulsatility index: a predictor of methotrexate resistance in gestational trophoblastic neoplasia

Background:

Neo-angiogenesis is a hallmark of cancer. The aim of this study was to test the hypothesis, in a prospective patient cohort, that in low-risk gestational trophoblastic neoplasia (LR-GTN) the uterine artery pulsatility index (UAPI), a measure of tumour vascularity, can predict resistance to methotrexate chemotherapy (MTX-R).

Methods:

286 LR-GTN patients (Charing Cross Hospital (CXH) score 0–8, or FIGO score 0–6) were treated with methotrexate between January 2008 and June 2011 at CXH. During staging investigations, patients underwent a Doppler ultrasound to assess the UAPI.

Results:

239 patients were assessable for both UAPI and MTX-R. The median UAPI was lower (higher vascularity) in MTX-R compared with MTX-sensitive patients (0.8 vs 1.4, P<0.0001). In multivariate logistic regression, UAPI⩽1 predicted MTX-R, independent of both CXH and FIGO scores. The risk of MTX-R in patients with a FIGO score of 6 and UAPI⩽1 was 100% vs 20% in patients with UAPI>1 (χ²P<0.0001).

Conclusion:

UAPI represents an independently validated clinically useful predictor of MTX-R in LR-GTN. Further, consideration of whether to incorporate UAPI into the FIGO scoring system is now warranted so that patients with a score of 6 and a UAPI ⩽1 might be upstaged and offered combination chemotherapy rather than MTX.