LPCAT1-TERT fusions are uniquely recurrent in epithelioid trophoblastic tumors and positively regulate cell growth

Placental Site Trophoblastic Tumors and Epithelioid Trophoblastic Tumors

Placental site trophoblastic disease (PSTT) and epithelioid trophoblastic tumor (ETT) are the rarest forms of gestational trophoblastic neoplasia (GTN) with unique clinical features and treatment considerations. Unlike other GTN, human chorionic gonadotropin (hCG) is minimally, if at all, elevated. Additionally, unlike other GTN, WHO risk scores are not applied to PSTT/ETT. Management of PSTT/ETT is predominately surgical with hysterectomy and possible lymphadenectomy. There are case reports of fertility sparing surgery for uterine confined disease. Multi-agent chemotherapy ± pembrolizumab is added for those with high risk features defined as advanced stage disease and those diagnosed ≥48 months from the antecedent pregnancy. Survival for early stage, low risk disease remains quite good but the prognosis for high-risk disease is poor and an scenario for which novel treatments are needed.

Pathology of Gestational Trophoblastic Disease (GTD)

Gestational trophoblastic disease (GTD), comprising hydatidiform moles (HM) and gestational trophoblastic tumors (GTT), is extremely rare. HM originate from villous trophoblast and are considered preneoplastic. GTT originate from the intermediate, largely extravillous trophoblast and includes choriocarcinoma, placental site trophoblastic tumor, epitheloid trophoblastic tumor, and mixed trophoblastic tumor. The abnormal (non-molar) villous lesions, non-malignant tumour-like conditions, and non-gestational tumors add to the diagnostic dilemma. The correct diagnosis and classification of these rare conditions are important. This review intends to provide an update on changes in the World Health Organization classification and focusses on the morphologic aspects in diagnosis of GTD.

Hypoxia and loss of GCM1 expression prevents differentiation and contact inhibition in human trophoblast stem cells

The placenta develops alongside the embryo and nurtures fetal development to term. During the first stages of embryonic development, due to low blood circulation, the blood and ambient oxygen supply is very low (~1-2% O2) and gradually increases upon placental invasion. While a hypoxic environment is associated with stem cell self-renewal and proliferation, persistent hypoxia may have severe effects on differentiating cells and could be the underlying cause of placental disorders. We find that human trophoblast stem cells (hTSC) thrive in low oxygen, whereas differentiation of hTSC to trophoblast to syncytiotrophoblast (STB) and extravillous trophoblast (EVT) is negatively affected by hypoxic conditions. The pro-differentiation factor GCM1 (human Glial Cell Missing-1) is downregulated in low oxygen, and concordantly there is substantial reduction of GCM1-regulated genes in hypoxic conditions. Knockout of GCM1 in hTSC caused impaired EVT and STB formation and function, reduced expression of differentiation-responsive genes, and resulted in maintenance of self-renewal genes. Treatment with a PI3K inhibitor reported to reduce GCM1 protein levels likewise counteracts spontaneous or directed differentiation. Additionally, chromatin immunoprecipitation of GCM1 showed enrichment of GCM1-specific binding near key transcription factors upregulated upon differentiation including the contact inhibition factor CDKN1C. Loss of GCM1 resulted in downregulation of CDKN1C and corresponding loss of contact inhibition, implicating GCM1 in regulation of this critical process.

Identification of LPCAT1 as a key biomarker for Crohn's disease based on bioinformatics and machine learnings and experimental verification

Epithelial-mesenchymal transition (EMT) plays a crucial role in regulating inflammatory responses and fibrosis formation. This study aims to explore the molecular mechanisms of EMT-related genes in Crohn's disease (CD) through bioinformatics methods and identify potential key biomarkers. In our research, we identified differentially expressed genes (DEGs) related to EMT based on the GSE52746 dataset and the gene set in the GeneCards database. Key genes were identified through Lasso-cox and Random Forest and validated using the external dataset GSE10616. Immune infiltration analysis showed that Lysophosphatidylcholine acyltransferase 1 (LPCAT1) was positively correlated with Neutrophils and Macrophages M1. The Gene Set Enrichment Analysis (GSEA) results for LPCAT1 showed associations with celladhesionmolecules and ECM receptor interaction. Additionally, a lncRNA-miRNA-mRNA ceRNA network was constructed. Finally, we validated that knocking down LPCAT1 could inhibit the release of inflammatory factors, EMT, and the elevation of fibrosis indices as well as the activation of NF-κB signaling pathway in LPS-induced HT-29 cells. LPCAT1 plays an important role in the occurrence and development of CD and may become a new biomarker.

Molecular Analyses of Chorionic-Type Intermediate Trophoblastic Lesions: Atypical Placental Site Nodules are Closer to Placental Site Nodules Than Epithelioid Trophoblastic Tumors

Gestational trophoblastic diseases derived from the chorionic-type intermediate trophoblast include benign placental site nodule (PSN) and malignant epithelioid trophoblastic tumor (ETT). Among PSNs, the World Health Organization classification introduced a new entity named atypical placental site nodule (APSN), corresponding to an ETT precursor, for which diagnostic criteria remain unclear, leading to a risk of overdiagnosis and difficulties in patient management. We retrospectively studied 8 PSNs, 7 APSNs, and 8 ETTs to better characterize this new entity and performed immunohistochemical analysis (p63, human placental lactogen, Cyclin E, and Ki67), transcriptional analysis using the NanoString method to quantify the expression of 760 genes involved in the main tumorigenesis pathways, and RNA sequencing to identify fusion transcripts. The immunohistochemical analysis did not reveal any significant difference in Cyclin E expression among the 3 groups (P = .476), whereas the Ki67 index was significantly (P < .001) higher in ETT samples than in APSN and PSN samples. None of the APSN samples harbored the LPCAT1::TERT fusion transcripts, in contrast to 1 of 6 ETT samples, as previously described in 2 of 3 ETT samples. The transcriptomic analysis allowed robust clustering of ETTs distinct from the APSN/PSN group but failed to differentiate APSNs from PSNs. Indeed, only 7 genes were differentially expressed between PSN and APSN samples; CCL19 upregulation and EPCAM downregulation were the most distinguishing features of APSNs. In contrast, 80 genes differentiated ETTs from APSNs, establishing a molecular signature for ETT. Gene set analysis identified significant enrichments in the DNA damage repair, immortality and stemness, and cell cycle signaling pathways when comparing ETTs and APSNs. These results suggested that APSN might not represent a distinct entity but rather a transitional stage between PSN and ETT. RNA sequencing and the transcriptional signature of ETT described herein could serve as triage for APSN from curettage or biopsy material, enabling the identification of cases that need further clinical investigations.

Clinical features and management of trophoblastic epithelioid tumors: A systematic review

BACKGROUND

This study aimed to systematically review the existing literature on epithelioid trophoblastic tumors (ETTs), the rarest type of gestational trophoblastic neoplasia.

METHODS

A systematic review according to PRISMA guidelines was performed, using ScienceDirect, Web of Science, and Scopus databases. The only filter used was the English language. Eligibility/inclusion criteria: retrospective observational studies (case reports, case series) including full case description of epithelioid trophoblastic tumor lesions.

RESULTS

Seventy studies were assessed for synthesis, including 147 cases. 66.7% of patients with ETT presented with irregular vaginal bleeding. Pretreatment β-hCG levels ranged up to 1000 mIU/mL in 58.5% patients. Of most patients, 42.2% had stage I disease, 10.9% stage II, 25.2% stage III, and 21.8% of patients had stage IV. The most common sites of metastatic disease were the lungs, followed by the liver and brain. After treatment, complete remission was achieved in 75.5% of patients, partial remission in 10.2% of patients, and 14.3% of patients died. On univariate and multivariate analyses, stage IV disease was an independent prognostic factor for overall and disease-free survival.

CONCLUSIONS

Hysterectomy and metastatic lesion resection are essential for controlling ETT. Investigational studies on molecules like EGFR, VEGF, PD-1, CD105, and LPCAT1 are potential therapeutic targets for metastatic ETT.

ncRNA-Mediated High Expression of LPCAT1 Correlates with Poor Prognosis and Tumor Immune Infiltration of Liver Hepatocellular Carcinoma

Purpose

To investigate the expression of LPCAT1 in liver hepatocellular carcinoma (LIHC) and its relationship with prognosis and immune infiltration and predict its upstream nonencoding RNAs (ncRNAs).

Method

In this study, expression analysis and survival analysis for LPCAT1 in pan cancers were first performed by using The Cancer Genome Atlas (TCGA) data, which suggested that LPCAT1 might be a potential LIHC oncogene. Then, ncRNAs contributing to the overexpression of LPCAT1 were explored in starBase by a combination of expression analysis, correlation analysis, and survival analysis. Immune cell infiltration of LPCAT1 in LIHC was finally investigated via Tumor Immune Estimation Resource (TIMER).

Result

SNHG3 was observed to be the most promising upstream lncRNA for the hsa-miR-139-5p/LPCAT1 axis in LIHC. In addition, the LPCAT1 level was significantly positively associated with tumor immune cell infiltration, biomarkers of immune cells, and immune checkpoint expression in LIHC.

Conclusion

To summarize, the upregulation of LPCAT1 mediated by ncRNAs is associated with poor prognosis, immune infiltration, and immune checkpoint expression in LIHC.