A Review on the Pathogenesis and Clinical Management of Placental Site Trophoblastic Tumors

A case of placental site trophoblastic tumor managed in a low resource setting

Placental trophoblastic site tumor (PSTT) is a rare type of gestational trophoblastic neoplasia (GTN). PSTT has a higher mortality than other types of gestational trophoblastic disease (GTD), with a rate of 16.1%, due to its relatively unpredictable behavior and reduced response to chemotherapy. Its diagnostic and management are very challenging in Low resources settings particularity in Haiti where MRI, PET Scan and IHC are not available. Further, the follow-up is very difficult because of social, political, and economic issues limiting the capacity of our patients to be present at all scheduled visits. No case of PSTT has been publicly described yet the Haitian experience in the literature in the management of such case compared to the developed world. We present a case of PSTT successfully diagnosed and managed at Mirebalais University Hospital (MUH) in Haiti with the support of telepathology and intentional partners while highlighting the difference that we observed compare to the developed world.

Placental Site Trophoblastic Tumour Mimicking Placenta Previa

ABSTRACT

We present a 42-year-old Nigerian woman who had three previous caesarean sections and is being managed conservatively for placenta previa. She underwent a caesarean hysterectomy on account of uncontrollable bleeding, and histopathology revealed a placental site trophoblastic tumour.

Placental-site trophoblastic tumor with bone metastasis: A diagnostic and therapeutic challenge

Placental-site trophoblastic tumor (PSTT) is a rare pathological entity included in the spectrum of gestational trophoblastic neoplasia (GTN). It is a neoplasia with metastatic potential that, once metastasized, has poor prognosis because the tumor tends to be less sensitive to chemotherapy. We present a rare case of gestational trophoblastic neoplasia, in which hysterectomy for persistent gestational trophoblastic disease after hydatidiform mole, revealed a primary PSTT in the uterus. Subsequently, a slight persistent elevation of the beta fraction of human chorionic gonadotropin hormone (B-hCG) during follow-up revealed the presence of bone metastases. This location is not usual from this tumor, being even more rare the case of PSTT with isolated bone metastases. Metastasic foci were only identified with PET-CT since the usual diagnostic resources were not able to do it. Finally, it is also remarkable in our case that the treatment required the confluence of chemotherapy together with immunotherapy to achieve a favorable response.

Placental site trophoblastic tumor (PSTT): a case report and review of the literature

Placental site trophoblastic tumor (PSTT), also known as atypical choriocarcinoma, syncytioma, chorioepitheliosis or trophoblastic pseudotumor, is a rare gestational trophoblastic disease (0.25-5% of all trophoblastic tumors) and it is composed by neoplastic proliferation of intermediate trophoblasts at placental implantation site. It consists of aggregates or sheets of large, polyhedral to round, predominantly mononucleated cells with a characteristic vascular and myometrial invasion. Main differential diagnoses are gestational choriocarcinoma (GC) and epitelioid trophoblastic tumor (ETT). We present a case of PSTT in a 25-year-old woman. Neoplastic cells showed moderate/high nuclear pleomorphism, abundant amphophilic, eosinophilic and clear cytoplasm, numerous mitotic figures (10 mitoses/10 HPF), and myometrial invasion. Other features are necrosis, vascular invasion with replacement of myometrial vessels by tumor cells and hemorrhage. The patient showed typical low serum β-hCG levels and high serum humane placental lactogen (hPL) levels.

Expression profiling of lncRNAs and mRNAs in placental site trophoblastic tumor (PSTT) by microarray

As a rare type of gestational trophoblastic disease, placental site trophoblastic tumor (PSTT) is originated from intermediate trophoblast cells. Long noncoding RNAs (lncRNAs) regulate numerous biological process. However, the role of lncRNAs in PSTT remains poorly understood. In the present study, expression levels of lncRNAs and mRNAs in four human PSTT tissues and four normal placental villi were investigated. The results of microarray were validated by the reverse transcription and quantitative real-time polymerase reaction (RT-qPCR) and immunohistochemistry analyses. Furthermore, GO and KEGG pathway analyses were performed to identify the underlying biological processes and signaling pathways of aberrantly expressed lncRNAs and mRNAs. We also conducted the coding-non-coding gene co-expression (CNC) network to explore the interaction of altered lncRNAs and mRNAs. In total, we identified 1247 up-regulated lncRNAs and 1013 down-regulated lncRNAs as well as 828 up-regulated mRNAs and 1393 down-regulated mRNAs in PSTT tissues compared to normal villi (fold change ≥ 2.0, p < 0.05). GO analysis showed that mitochondrion was the most significantly down-regulated GO term, and immune response was the most significantly up-regulated term. A CNC network profile based on six confirmed lncRNAs (NONHSAT114519, NR_103711, NONHSAT003875, NONHSAT136587, NONHSAT134431, NONHSAT102500) as well as 354 mRNAs was composed of 497 edges. GO and KEGG analyses indicated that interacted mRNAs were enriched in the signal-recognition particle (SRP)-dependent cotranslational protein targeting to membrane and Ribosome pathway. It contributes to expand the understanding of the aberrant lncRNAs and mRNAs profiles of PSTT, which may be helpful for the exploration of new diagnosis and treatment of PSTT.

PLAC8 promotes the autophagic activity and improves the growth priority of human trophoblast cells

Autophagy plays an important role in the normal development and function of trophoblast cells and is precisely regulated during pregnancy. Dysregulated autophagy contributes to the abnormal proliferation of trophoblasts, which is closely related to the occurrence of pregnancy-related diseases. Placenta specific 8 (PLAC8, Onzin) is a multifaceted protein proven to promote autophagy and potentiate various tumor progression. Its role in trophoblasts remains elusive. In our present study, PLAC8 expression was detected in tissues of first-trimester placentas (n = 5), term placentas (n = 5), choriocarcinoma (n = 5), and placental site trophoblastic tumor (n = 5). PLAC8 expression was increased in gestational neoplasms compared with normal pregnancies. mCherry-EGFP-LC3B reporter and transmission electron microscopy confirmed PLAC8 promoted the autophagic flux of human trophoblast cells. Both gain-of-function and loss-of-function experiments demonstrated PLAC8-regulated autophagy-related genes, including ATG5, ATG12, and Beclin-1. In addition, our data showed that PLAC8 co-localized with p53 and promoted its degradation, and p53 re-expression partially abrogated the PLAC8-induced autophagy activity. Furthermore, the overexpression of PLAC8 promoted cell viability and proliferation, acting as a protective mechanism of trophoblasts against the cytotoxicity of etoposide (VP-16). Such a phenomenon was effectively abrogated by autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ). In conclusion, PLAC8-induced autophagy to promote the proliferation of trophoblasts. This study provided insights into the mechanism of PLAC8-induced autophagy in trophoblasts, which is significant for a wide range of gestational diseases and may contribute to developing novel treatment strategies for trophoblastic diseases.

Her2-Targeted Multifunctional Nano-Theranostic Platform Mediates Tumor Microenvironment Remodeling and Immune Activation for Breast Cancer Treatment

Purpose

The treatment of breast cancer is often ineffective due to the protection of the tumor microenvironment and the low immunogenicity of tumor cells, leading to a poor therapeutic effect. In this study, we designed a nano-theranostic platform for these obstacles: a photothermal effect mediated by a gold shell could remodel the tumor microenvironment by decreasing cancer-associated fibroblasts (CAFs) and promote the release of doxorubicin (DOX) from nanoparticles. In addition, it could realize photoacoustic (PA)/MRI dual-model imaging for diagnose breast cancer and targeted identification of Her2-positive breast cancer.

Methods

Her2-DOX-superparamagnetic iron oxide nanoparticles (SPIOs)@Poly (D, L-lactide-co-glycolide) acid (PLGA)@Au nanoparticles (Her2-DSG NPs) were prepared based on a single emulsion oil-in-water (O/W) solvent evaporation method, gold seed growing method, and carbon diimide method. The size distribution, morphology, PA/MRI imaging, drug loading capacity, and drug release were investigated. Cytotoxicity, antitumor effect, cellular uptake, immunogenic cell death (ICD) effect, and targeted performance on human Her2-positive BT474 cell line were investigated in vitro. BT474/Adr cells were constructed and the antitumor effect of NPs on it was evaluated in vitro. Moreover, chemical-photothermal therapy effect, PA/MRI dual-model imaging, ICD effect induced by NPs, and tumor microenvironment remodeling in human BT474 breast cancer nude mice model were also investigated.

Results

Nanoparticles were spherical, uniform in size and covered with a gold shell. NPs had a photothermal effect, and can realize photothermal-controlled drug release in vitro. Chemical-photothermal therapy had a good antitumor effect on BT474/Adr cells and on BT474 cells in vitro. The targeting evaluation in vitro showed that Her2-DSG NPs could actively target and identify Her2-positive tumor cells. The PA/MRI imaging was successfully validated in vitro/vivo. Similarly, NPs could enhance the ICD effect in vitro/vivo, which could activate an immune response. Immunofluorescence results also proved that photothermal effect could decrease CAFs to remodel the tumor microenvironment and enhance the accessibility of NPs to tumor cells. According to the toxicity results, targeted drug delivery combined with photothermal-responsive drug release proved that NPs had good biosafety in vivo. Chemical-photothermal therapy of Her2-targeted NPs has a good antitumor effect in the BT474 nude mice model.

Conclusion

Our study showed that chemical-photothermal therapy combined with tumor microenvironment remodeling and immune activation based on the Her2-DSG NPs we developed are very promising for Her2-positive breast cancer.

Sequential metastasis to the liver and pancreas 4 years after gestational trophoblastic neoplasia: a case report

This case report describes a 43-year-old female initially diagnosed with gestational trophoblastic neoplasia that then experienced metastasis to the liver and then subsequently to the pancreas nearly 4 years after the primary diagnosis. After resection of the body and tail of the pancreas, the postoperative histopathological examination confirmed a placental site trophoblastic tumour that had developed after several cycles of chemotherapy for the original primary tumour and the liver metastases. This type of sequential recurrence of gestational trophoblastic neoplasia in the primary site or metastatic sites, such as the liver or pancreas, can be cured by a comprehensive treatment strategy involving surgery and/or salvage chemotherapy and continuous follow-up over a long period, especially for patients with a high-risk status.

Placental site trophoblastic tumour and epithelioid trophoblastic tumour

Placental site trophoblastic tumour (PSTT) and epithelioid trophoblastic tumour (ETT) are the rarest subtypes of gestational trophoblastic disease (GTD). Their diagnosis is complicated and lacks specific and sensitive tumour markers. They are slow-growing tumours and can occur months to years after any type of antecedent pregnancy. The primary treatment for localised disease is hysterectomy. However, extra-uterine invasion and/or metastasis occur in about one-third of cases and still cause death in a small number. Most patients are young; hence, fertility preservation is a consideration. The major obstacle for prognosis is chemotherapy resistance. The current understanding of these tumours remains elusive and no randomized controlled trials have been done. Even those centres treating a large number of patients with GTD will infrequently manage PSTT/ETT. In this review, we assess progress in the understanding of the disease and discuss four main clinical challenges - establishing conformity of practice, devising a risk-adapted approach to clinical management, establishing long-term follow-up data and evaluating therapies for poor prognosis and multi drug-resistant patients.

MAP Kinase driven actomyosin rearrangement is a crucial regulator of monocyte to macrophage differentiation

Rearrangement of actin cytoskeleton correlates significantly with the immune responses as the perturbation of cytoskeletal dynamics leads to many immune deficiencies. Mechanistic insights into this correlation remain unknown. Cellular spreading, the most characteristic phenotype associated with monocyte to macrophage differentiation, led us to investigate the contribution of actomyosin dynamics in monocyte differentiation. Our observation revealed that actomyosin reorganization intrinsically governs the process of monocyte to macrophage differentiation. Further, we established that the MAPK-driven signaling pathways regulate the cellular actomyosin dynamics that direct monocyte to macrophage differentiation. We also identified P42/44 Mitogen-Activated Protein Kinase (P42/44 MAPK), P38 Mitogen-Activated Protein Kinase (P38 MAPK), MAP Kinase Activated Protein Kinase 2 (MK-2), Heat Shock Protein 27 (Hsp-27), Lim Kinase (Lim K), non-muscle cofilin (n-cofilin), Myosin Light Chain Kinase (MLCK) and Myosin Light Chain (MLC) as critical components of the signaling network. Moreover, we have shown the involvement of the same signaling cascade in 3D gel-like microenvironment induced spontaneous monocyte to macrophage differentiation and in human blood-derived PBMC differentiation. Our study reveals new mechanistic insights into the process of monocyte to macrophage differentiation.