Cell State of Origin Impacts Development of Distinct Endometriosis-Related Ovarian Carcinoma Histotypes

Single-cell technology: the key to an improved understanding of the human endometrium in health and disease

Cyclic exposure of the endometrium to ovarian sex steroids during the menstrual cycle induces a transition between proliferative and receptive states involving a different variety of cell types (ie, epithelial, stromal, endothelial, and immune cells) in preparation for embryo implantation during the narrow window of implantation. The study of the female reproductive system cells across these different phases contributes to our understanding of the healthy endometrium at the cellular level, supporting comparisons with pathological conditions, such as endometriosis, endometrial cancer, or Asherman's syndrome. Single-cell RNA sequencing technology represents a powerful tool that can discern the gene expression profiles of each cell within a tissue sample and has recently revealed the complex collaborations taking place between diverse cell types during the distinct endometrial phases. This review aims to summarize those studies that have employed single-cell RNA sequencing to deepen our understanding of the endometrium at single-cell resolution during the menstrual cycle. We discuss the transitions taken by distinct cell populations across the proliferative and secretory phases and the general importance of these transitions to successful embryo implantation. Furthermore, we analyze the use of single-cell RNA sequencing technology to study in vitro models of healthy endometrium and endometrial carcinoma. We believe that future studies using single-cell RNA sequencing will be essential to understanding the behavior of the endometrium as a whole and identifying potential avenues for the improved management of endometrial diseases.

Impact of BRCA mutations, age, surgical indication, and hormone status on the molecular phenotype of the human Fallopian tube

The human Fallopian tube (FT) is an important organ in the female reproductive system and has been implicated as a site of origin for pelvic serous cancers, including high-grade serous tubo-ovarian carcinoma (HGSC). We have generated comprehensive whole-genome bisulfite sequencing, RNA-seq, and proteomic data of over 100 human FTs, with detailed clinical covariate annotations. Our results challenge existing paradigms that extensive epigenetic, transcriptomic and proteomic alterations exist in the FTs from women carrying heterozygous germline BRCA1/2 pathogenic variants. We find minimal differences between BRCA1/2 carriers and non-carriers prior to loss of heterozygosity. Covariates such as age and surgical indication can confound BRCA1/2-related differences reported in the literature, mainly through their impact on cell composition. We systematically document and highlight the degree of variations across normal human FT, defining five groups capturing major cellular and molecular changes across various reproductive stages, pregnancy, and aging. We are able to associate gene, protein, and epigenetic changes with these and other clinical covariates, but not heterozygous BRCA1/2 mutation status. This sheds new light into prevention and early detection of tumorigenesis in populations at high-risk for ovarian cancer.

Establishment of a Novel In Vitro and In Vivo Model to Understand Molecular Carcinogenesis of Endometriosis-Related Ovarian Neoplasms

The molecular mechanisms through which endometriosis-related ovarian neoplasms (ERONs) develop from benign endometrioma remain unclear. It is especially a long-standing mystery why ovarian endometrioma has the potential to develop into two representative histological subtypes: endometrioid ovarian carcinoma or clear cell ovarian carcinoma. This study aimed to investigate the molecular carcinogenesis of ERONs using newly developed in vitro and in vivo carcinogenesis models. Epithelial cells were isolated and purified from surgically removed benign endometrioma samples, followed by immortalization by overexpressing cyclinD1/CDK4 in combination with the human TERT gene. Immortalized cells were subjected to various molecular manipulations by combining knockout or overexpression of several candidate drivers, including ARID1A, KRAS, PIK3CA, AKT, and MYC, based on previous comprehensive genome-wide studies of ERONs. These cells were then inoculated into immunocompromised mice and evaluated for malignant transformation. Inoculated cells harboring a combination of three genetic alterations successfully developed tumors with malignant features in mice, whereas those with two genetic manipulations failed to do so. Especially, ARID1A gene knockout, combined with overexpressing the KRAS oncogenic mutant allele (or overexpressing AKT) and c-Myc overexpression led to efficient tumor formation. Of note, these three combinations of genetic alterations produced tumors that histologically represented typical clear cell carcinoma in SCID mice, while the same combination led to tumors with endometrioid histology in nude mice. A combination of ARID1A mutation, KRAS mutation or AKT activation, and c-Myc overexpression were confirmed to be the main candidate drivers for the development of ERONs, as suggested by comprehensive genetic analyses of ERONs. A tumor immune microenvironment involving B-cell signaling may contribute to the diverse histological phenotypes. The present model may help to clarify the molecular mechanisms of ERON carcinogenesis and understand their histological diversity and novel molecular targets.

Genetic and therapeutic heterogeneity shape the baseline and longitudinal immune ecosystem of ovarian clear cell carcinoma

BACKGROUND

Ovarian clear cell carcinoma (OCCC) is a rare and chemo-resistant subtype of ovarian cancer. While immunotherapy has demonstrated effectiveness in some OCCC cases, the mechanisms for heterogeneous immunoreactivity and potential combinatory strategies remain unclear.

METHODS

Tumor samples from 13 patients with OCCC underwent single-cell mRNA-seq and TCR-seq to generate 1 40 683 cells transcriptome, while additionally 31 formalin-fixed paraffin-embedded samples were used for immunohistochemistry. Spatial transcriptomics of two OCCC samples and bulk RNA-seq of 58 patients were incorporated for spatial and interpatient level explorations. Serum tumor markers and radiologic images of three patients with OCCC who received combinatory VEGF and PD-1 inhibition were retrospectively analyzed.

RESULTS

OCCC exhibited a dynamic immune architecture shaped by genetic and therapeutic pressure. ARID1A mutation linked to baseline immune activation, correlated with an enrichment of neoantigen-reactive CXCL13+ CTLA4+ CD8+ T cells (p<0.001) and enhanced FASLG-FAS interactions. Recurrent OCCC was fibrotic, angiogenic, and immunosuppressive, exhibiting metabolic reprogramming towards activated activity in fatty acid metabolism. High CD36 (log-rank p=0.012, HR: 4.515) and CD47 expression (log-rank p=0.037, HR: 3.246) indicated worse progression-free survival. Treatment with bevacizumab increased intratumoral T cell infiltration and activated T cell interferon-γ signaling. Retrospective analysis of clinical cases revealed that combination therapy with anti-VEGF (vascular endothelial growth factor) and anti-PD-1 agents exerted clinical benefits in patients with OCCC with persistent, recurrent, and metastatic disease.

CONCLUSIONS

ARID1A mutation correlated with OCCC baseline immune activation. Stromal reconstruction and tumor metabolic reprogramming functioned as key processes of OCCC dynamic progression. VEGF inhibition remodeled OCCC stroma, restored T cell function and potentiated immunotherapy. CD36 and CD47 might be potential therapeutic targets for recurrent OCCC.

Molecular classification of ovarian high-grade serous/endometrioid carcinomas through multi-omics analysis: JGOG3025-TR2 study

BACKGROUND

Considerable interobserver variability exists in diagnosis of ovarian high-grade endometrioid carcinoma (HGEC) and high-grade serous carcinoma (HGSC) due to histopathological similarities. While homologous recombination deficiency (HRD) correlates with drug sensitivity in HGSC, the molecular features of HGEC are unclear.

METHODS

Fresh-frozen samples from 15 ovarian HGECs and 274 ovarian HGSCs in the JGOG-TR2 cohort were submitted to targeted DNA sequencing, RNA sequencing, DNA methylation array, and SNP array. We additionally analyzed 555 ovarian HGSCs from TCGA-OV and 287 endometrial high-grade carcinomas from TCGA-UCEC.

RESULTS

Unsupervised clustering using copy number signatures identified four distinct tumor groups (C1, C2, C3 and C4). C1 (n = 41) showed CCNE1 amplification and poor survival. C2 (n = 160) and C3 (n = 59) showed high BRCA1/2 alteration frequency with low and moderate ploidy, respectively. C4 (n = 22) was characterized by favorable outcome, higher HGEC proportion, no BRCA1/2 alteration or CCNE1 amplification, and low levels of HRD score, ploidy, intra-tumoral heterogeneity, cell proliferation rate, and WT1 gene expression. Notably, C4 exhibited a normal endometrium-like DNA methylation profile, thus, defined as "HGEC-type" tumors, which were also identified in TCGA-OV and TCGA-UCEC.

CONCLUSIONS

Ovarian "HGEC-type" tumors present a non-HRD status, favorable prognosis, and endometrial differentiation, possibly constituting a subset of clinically diagnosed HGSCs.

The role of epigenetics in women's reproductive health: the impact of environmental factors

This paper explores the significant role of epigenetics in women's reproductive health, focusing on the impact of environmental factors. It highlights the crucial link between epigenetic modifications-such as DNA methylation and histones post-translational modifications-and reproductive health issues, including infertility and pregnancy complications. The paper reviews the influence of pollutants like PM2.5, heavy metals, and endocrine disruptors on gene expression through epigenetic mechanisms, emphasizing the need for understanding how dietary, lifestyle choices, and exposure to chemicals affect gene expression and reproductive health. Future research directions include deeper investigation into epigenetics in female reproductive health and leveraging gene editing to mitigate epigenetic changes for improving IVF success rates and managing reproductive disorders.

Redox-Regulated Iron Metabolism and Ferroptosis in Ovarian Cancer: Molecular Insights and Therapeutic Opportunities

Ovarian cancer (OC), known for its lethality and resistance to chemotherapy, is closely associated with iron metabolism and ferroptosis-an iron-dependent cell death process, distinct from both autophagy and apoptosis. Emerging evidence suggests that dysregulation of iron metabolism could play a crucial role in OC by inducing an imbalance in the redox system, which leads to ferroptosis, offering a novel therapeutic approach. This review examines how disruptions in iron metabolism, which affect redox balance, impact OC progression, focusing on its essential cellular functions and potential as a therapeutic target. It highlights the molecular interplay, including the role of non-coding RNAs (ncRNAs), between iron metabolism and ferroptosis, and explores their interactions with key immune cells such as macrophages and T cells, as well as inflammation within the tumor microenvironment. The review also discusses how glycolysis-related iron metabolism influences ferroptosis via reactive oxygen species. Targeting these pathways, especially through agents that modulate iron metabolism and ferroptosis, presents promising therapeutic prospects. The review emphasizes the need for deeper insights into iron metabolism and ferroptosis within the redox-regulated system to enhance OC therapy and advocates for continued research into these mechanisms as potential strategies to combat OC.

Regulated Cell Death in Endometriosis

Regulated cell death (RCD) represents a distinct mode of cell demise, differing from accidental cell death (ACD), characterized by specific signaling cascades orchestrated by diverse biomolecules. The regular process of cell death plays a crucial role in upholding internal homeostasis, acting as a safeguard against biological or chemical damage. Nonetheless, specific programmed cell deaths have the potential to activate an immune-inflammatory response, potentially contributing to diseases by enlisting immune cells and releasing pro-inflammatory factors. Endometriosis, a prevalent gynecological ailment, remains incompletely understood despite substantial progress in unraveling associated signaling pathways. Its complexity is intricately tied to the dysregulation of inflammatory immune responses, with various RCD processes such as apoptosis, autophagic cell death, pyroptosis, and ferroptosis implicated in its development. Notably, limited research explores the association between endometriosis and specific RCD pathways like pyroptosis and cuproptosis. The exploration of regulated cell death in the context of endometriosis holds tremendous potential for further advancements. This article thoroughly reviews the molecular mechanisms governed by regulated cell death and their implications for endometriosis. A comprehensive understanding of the regulated cell death mechanism in endometriosis has the potential to catalyze the development of promising therapeutic strategies and chart the course for future research directions in the field.

Editorial on the Special Issue Titled "Pathology and Diagnosis of Gynecologic Diseases"

In the medical and diagnostic daily routine, gynecologic diseases present many different scenarios [...].