The etiology and pathophysiology of endometriosis remain unclear. Accumulating evidence suggests that aberrant microRNA (miRNA) and transcription factor (TF) expression may be involved in the pathogenesis and development of endometriosis. This study therefore aims to survey the key miRNAs, TFs and genes and further understand the mechanism of endometriosis. Paired expression profiling of miRNA and mRNA in ectopic endometria compared with eutopic endometria were determined by high-throughput sequencing techniques in eight patients with ovarian endometriosis. Binary interactions and circuits among the miRNAs, TFs, and corresponding genes were identified by the Pearson correlation coefficients. miRNA-TF-gene regulatory networks were constructed using bioinformatic methods. Eleven selected miRNAs and TFs were validated by quantitative reverse transcription-polymerase chain reaction in 22 patients. Overall, 107 differentially expressed miRNAs and 6112 differentially expressed mRNAs were identified by comparing the sequencing of the ectopic endometrium group and the eutopic endometrium group. The miRNA-TF-gene regulatory network consists of 22 miRNAs, 12 TFs and 430 corresponding genes. Specifically, some key regulators from the miR-449 and miR-34b/c cluster, miR-200 family, miR-106a-363 cluster, miR-182/183, FOX family, GATA family, and E2F family as well as CEBPA, SOX9 and HNF4A were suggested to play vital regulatory roles in the pathogenesis of endometriosis. Integration analysis of the miRNA and mRNA expression profiles presents a unique insight into the regulatory network of this enigmatic disorder and possibly provides clues regarding replacement therapy for endometriosis.

Endometriosis is a complex and enigmatic disease that arises from the interplay among multiple genetic and environmental factors. The defining feature of endometriosis is the deposition and growth of endometrial tissues at sites outside of the uterine cavity. Studies to date have established that endometriosis is heritable but have not addressed the causal genetic variants for this disease. Here, we conducted whole-exome sequencing to comprehensively search for somatic mutations in both eutopic and ectopic endometrium from 16 endometriosis patients and five normal control patients using laser capture microdissection. We compared the mutational landscape of ectopic endometrium with the corresponding eutopic sample from endometriosis patients compared with endometrium from normal women and identified previously unreported mutated genes and pathway alternations. Statistical analysis of exome data identified that most genes were specifically mutated in both eutopic and ectopic endometrium cells. In particular, genes that are involved in biological adhesion, cell–cell junctions, and chromatin-remodeling complex(es) were identified, which partially supports the retrograde menstruation theory that proposes that endometrial cells are refluxed through the fallopian tubes during menstruation and implanted onto the peritoneum or pelvic organs. Conspicuously, when we compared exomic mutation data for paired eutopic and ectopic endometrium, we identified a mutational signature in both endometrial types for which no overlap in somatic single nucleotide variants were observed. These mutations occurred in a mutually exclusive manner, likely because of the discrepancy in endometriosis pathology and physiology, as eutopic endometrium rapidly regrows, and ectopic endometrial growth is inert. Our findings provide, to our knowledge, an unbiased view of the landscape of genetic alterations in endometriosis and vital information for indicating that genetic alterations in cytoskeletal and chromatin-remodeling proteins could be involved in the pathogenesis of endometriosis, thus implicating a novel therapeutic possibility for endometriosis.

Background/Aims: Mitochondrial homeostasis is implicated in the development and progression of endometriosis through poorly defined mechanisms. Mst1 is the major growth suppressor related to cancer migration, apoptosis and proliferation. However, whether Mst1 is involved in endometriosis apoptosis and migration via regulating the mitochondrial function remains to be elucidated. Methods: Expression of Mst1 in endometriosis was examined via western blots. Cellular apoptosis was detected via MTT and TUNEL assay. Gain of function assay about Mst1 was conducted via adenovirus over-expression. Mitochondrial functions were evaluated via mitochondrial membrane potential JC-1 staining, ROS flow cytometry analysis, mPTP opening assessment and immunofluorescence of HtrA2/Omi. The mitophagy activity were examined via western blots and immunofluorescence. Results: First, we found that Mst1 was significantly downregulated in the ectopic endometrium of endometriosis compared to the normal endometrium. However, the recovery of Mst1 function was closely associated with the inability of endometrial stromal cells (ESCs) to migrate and survive. A functional study indicated that regaining Mst1 enhanced Drp1 post-transcriptional phosphorylation at Ser616 and repressed Parkin transcription activity via p53, leading to mitochondrial fission activation and mitophagy inhibition. Excessive Drp1-related fission forced the mitochondria to liberate HtrA2/Omi into the cytoplasm. Moreover, Mst1-induced defective mitophagy evoked cellular oxidative stress, energy metabolism and calcium overload. Through excessive mitochondrial fission and aberrant mitophagy, Mst1 launched caspase 9-related mitochondrial apoptosis and abrogated F-actin/lamellipodium-dependent cellular migration. Notably, we also defined NR4A/miR181c as the upstream signal for Mst1 dysfunction in endometriosis. Conclusion: Collectively, our results comprehensively described the important role of the NR4A-miR181c-Mst1 pathway in endometriosis, which handled mitochondrial apoptosis and F-actin/ lamellipodium-based migration via the regulation of Drp1-related mitochondrial fission and Parkin-required mitophagy, with a potential application in endometriosis therapy by limiting ESCs migration and promoting apoptosis.

Classification of ovarian cancer by morphologic features has a limited effect on serous ovarian cancer (SOC) treatment and prognosis. Here, we proposed a new system for SOC subtyping based on the molecular categories from the Cancer Genome Atlas project. We analyzed the DNA methylation, protein, microRNA and gene expression of 1203 samples from 599 serous ovarian cancer patients. These samples were divided into nine subtypes based on RNA-seq data and each subtype was found to be associated with the activation and/or suppression of the following four biological processes: immunoactivity, hormone metabolic, mesenchymal development and the MAPK signaling pathway. We also identified four DNA methylation, two protein expression, six microRNA sequencing and four pathway subtypes. By integrating the subtyping results across different omics platforms, we found that most RNA-seq subtypes overlapped with one or two subtypes from other omics data. Our study sheds light on the molecular mechanisms of SOC and provides a new perspective for the more accurate stratification of its subtypes.

The goal of this work was to investigate the tumor mutational burden (TMB) in Chinese patients with gynecologic cancer. In total, 117 patients with gynecologic cancers were included in this study. Both tumor DNA and paired blood cell genomic DNA were isolated from formalin-fixed paraffin-embedded (FFPE) specimens and blood samples, and next-generation sequencing was performed to identify somatic mutations. TP53, PTEN, ARID1A, and PIK3CA alterations were significantly different in various types of gynecologic cancers (p = 0.001, 1.15E-07, 0.004, and 0.009, respectively). The median TMB of all 117 gynecologic tumor specimens was 0.37 mutations/Mb, with a range of 0–41.45 mutations/Mb. Despite the lack of significant difference, endometrial cancer cases had a higher median TMB than cervical and ovarian cancer cases. Younger gynecologic cancer patients (age <40 years) had a significantly lower TMB than older patients (age ≥40 years) (p = 0.04). In addition, TMB was significantly increased with increasing clinical stage of disease (p = 0.001). PTEN alterations were commonly observed in patients with a moderate to high TMB (n = 8, 38.10%, p = 9.95E-04). Although limited by sample size, all of the patients with TSC2 (n = 3, p = 3.83E-11) or POLE (n = 2, p = 0.005) mutations had a moderate to high TMB. Further large-scale, prospective studies are needed to validate our findings.