The Mediator complex: a central integrator of transcription.

The RNA polymerase II (Pol II) enzyme transcribes all protein-coding and most non-coding RNA genes and is globally regulated by Mediator - a large, conformationally flexible protein complex with a variable subunit composition (for example, a four-subunit cyclin-dependent kinase 8 module can reversibly associate with it). These biochemical characteristics are fundamentally important for Mediator's ability to control various processes that are important for transcription, including the organization of chromatin architecture and the regulation of Pol II pre-initiation, initiation, re-initiation, pausing and elongation. Although Mediator exists in all eukaryotes, a variety of Mediator functions seem to be specific to metazoans, which is indicative of more diverse regulatory requirements.

Deficient H2A.Z deposition is associated with genesis of uterine leiomyoma.

One in four women suffers from uterine leiomyomas (ULs)-benign tumours of the uterine wall, also known as uterine fibroids-at some point in premenopausal life. ULs can cause excessive bleeding, pain and infertility1, and are a common cause of hysterectomy2. They emerge through at least three distinct genetic drivers: mutations in MED12 or FH, or genomic rearrangement of HMGA23. Here we created genome-wide datasets, using DNA, RNA, assay for transposase-accessible chromatin (ATAC), chromatin immunoprecipitation (ChIP) and HiC chromatin immunoprecipitation (HiChIP) sequencing of primary tissues to profoundly understand the genesis of UL. We identified somatic mutations in genes encoding six members of the SRCAP histone-loading complex4, and found that germline mutations in the SRCAP members YEATS4 and ZNHIT1 predispose women to UL. Tumours bearing these mutations showed defective deposition of the histone variant H2A.Z. In ULs, H2A.Z occupancy correlated positively with chromatin accessibility and gene expression, and negatively with DNA methylation, but these correlations were weak in tumours bearing SRCAP complex mutations. In these tumours, open chromatin emerged at transcription start sites where H2A.Z was lost, which was associated with upregulation of genes. Furthermore, YEATS4 defects were associated with abnormal upregulation of bivalent embryonic stem cell genes, as previously shown in mice5. Our work describes a potential mechanism of tumorigenesis-epigenetic instability caused by deficient H2A.Z deposition-and suggests that ULs arise through an aberrant differentiation program driven by deranged chromatin, emanating from a small number of mutually exclusive driver mutations.

Deregulated Expression of Mammalian lncRNA through Loss of SPT6 Induces R-Loop Formation, Replication Stress, and Cellular Senescence.

Extensive tracts of the mammalian genome that lack protein-coding function are still transcribed into long noncoding RNA. While these lncRNAs are generally short lived, length restricted, and non-polyadenylated, how their expression is distinguished from protein-coding genes remains enigmatic. Surprisingly, depletion of the ubiquitous Pol-II-associated transcription elongation factor SPT6 promotes a redistribution of H3K36me3 histone marks from active protein coding to lncRNA genes, which correlates with increased lncRNA transcription. SPT6 knockdown also impairs the recruitment of the Integrator complex to chromatin, which results in a transcriptional termination defect for lncRNA genes. This leads to the formation of extended, polyadenylated lncRNAs that are both chromatin restricted and form increased levels of RNA:DNA hybrid (R-loops) that are associated with DNA damage. Additionally, these deregulated lncRNAs overlap with DNA replication origins leading to localized DNA replication stress and a cellular senescence phenotype. Overall, our results underline the importance of restricting lncRNA expression.

Spatially restricted ecto-5'-nucleotidase expression promotes the growth of uterine leiomyomas by modulating Akt activity.

Found in as many as 80% of women, uterine leiomyomas are a frequent cause of abnormal uterine bleeding, pelvic pain, and infertility. Despite their significant clinical impact, the mechanisms responsible for driving leiomyoma growth remain poorly understood. After obtaining IRB permission, expression of ecto-5'-nucleotidase (NT5E, CD73) was assessed in matched specimens of myometrium and leiomyoma by real-time qPCR, Western blot, and immunohistochemistry (IHC). Adenosine concentrations were measured by enzyme-linked assay. Primary cultures were used to assess the impact of adenosine and/or adenosine receptor agonists on proliferation, apoptosis, and patterns of intracellular signaling in vitro. When compared to matched specimens of healthy myometrium, uterine leiomyomas were characterized by reduced CD73 expression. Largely limited to thin-walled vascular structures and the pseudocapsule of leiomyomas despite diffuse myometrial distribution. Restricted intra-tumoral CD73 expression was accompanied by decreased levels of intra-tumoral adenosine. In vitro, incubation of primary leiomyoma cultures with adenosine or its hydrolysis-resistant analog 2-chloro-adenosine (2-CL-AD) inhibited proliferation, induced apoptosis, and reduced proportion of myocytes in S- and G2-M phases of the cell cycle. Decreased proliferation was accompanied by reduced expression of phospho-Akt, phospho-Cdk2-Tyr15, and phospho-Histone H3. Enforced expression of the A2B adenosine receptor (ADORA2B) and ADORA2B-selective agonists similarly suppressed proliferation and inhibited Akt phosphorylation. Collectively, these observations broadly implicate CD73 and reduced extracellular concentrations of adenosine as key regulators of leiomyoma growth and potentially identify novel strategies for clinically managing these common tumors.

Targeting Galectin 3 illuminates its contributions to the pathology of uterine serous carcinoma.

BACKGROUND: Uterine serous cancer (USC) comprises around 10% of all uterine cancers. However, USC accounts for approximately 40% of uterine cancer deaths, which is attributed to tumor aggressiveness and limited effective treatment. Galectin 3 (Gal3) has been implicated in promoting aggressive features in some malignancies. However, Gal3's role in promoting USC pathology is lacking. METHODS: We explored the relationship between LGALS3 levels and prognosis in USC patients using TCGA database, and examined the association between Gal3 levels in primary USC tumors and clinical-pathological features. CRISPR/Cas9-mediated Gal3-knockout (KO) and GB1107, inhibitor of Gal3, were employed to evaluate Gal3's impact on cell function. RESULTS: TCGA analysis revealed a worse prognosis for USC patients with high LGALS3. Patients with no-to-low Gal3 expression in primary tumors exhibited reduced clinical-pathological tumor progression. Gal3-KO and GB1107 reduced cell proliferation, stemness, adhesion, migration, and or invasion properties of USC lines. Furthermore, Gal3-positive conditioned media (CM) stimulated vascular tubal formation and branching and transition of fibroblast to cancer-associated fibroblast compared to Gal3-negative CM. Xenograft models emphasized the significance of Gal3 loss with fewer and smaller tumors compared to controls. Moreover, GB1107 impeded the growth of USC patient-derived organoids. CONCLUSION: These findings suggest inhibiting Gal3 may benefit USC patients.

Racial disparity in uterine leiomyoma: new insights of genetic and environmental burden in myometrial cells.

Uterine leiomyoma (LM), also known as uterine fibroids, are common gynecological tumors and can reach a prevalence of 70% among women by the age of 50 years. Notably, the LM burden is much higher in Black women with earlier onset, a greater tumor number, size, and severity compared to White women. Published knowledge shows that there are genetic, environmental, and lifestyle-based risk factors associated with racial disparity for LM. Significant strides have been made on genomic, epigenomic, and transcriptomic data levels in Black and White women to elucidate the underlying pathomolecular reasons of racial disparity in LM development. However, racial disparity of LM remains a major area of concern in gynecological research. This review highlights risk factors of LM and their role in different races. Furthermore, we discuss the genetics and uterine myometrial microenvironment in LM development. Comparative findings revealed that a major racial difference in the disease is linked to myometrial oxidative burden and altered ROS pathways which is relevant to the oxidized guanine in genomic DNA and MED12 mutations that drive the LM genesis. Considering the burden and morbidity of LM, we anticipate that this review on genetic risk and myometrial microenvironment will strengthen understanding and propel the growth of research to address the racial disparity of LM burden.

Hypermethylated RASAL1's promotive role in chemoresistance and tumorigenesis of choriocarcinoma was regulated by TET2 but not DNMTs.

BACKGROUND: Patients with choriocarcinoma (CC) accompanying chemoresistance conventionally present a poor prognosis. Whether ras protein activator like-1 (RASAL1) functions as a tumor promoter or suppressor depends on tumor types. However, the role of RASAL1 in process of chemoresistance of CC and underlying molecular mechanism remain elusive. METHODS: The expression pattern of RASAL1 in CC cells and tissues was measured using Western blotting, immunohistochemistry and qRT-PCR. Cell viability and proliferative ability were assessed by MTT assay, Tunnel assay and flow cytometric analysis. Additionally, the stemness was evaluated by the colony formation and tumor sphere formation. Methotrexate (MTX) was applied to exam the chemosensitivity of CC cells. RESULTS: The expression of RASAL1 was reduced both at the protein and mRNA levels in CC tissues and cells compared to hydatidiform mole (HM) and invasive mole (IM). Loss of RASAL1 was attributed to its promoter hypermethylation and could be restored by 5-Aza. Knock-down of RASAL1 promoted the viability, proliferative potential, stemness and EMT phenotype of JEG-3 cells. However, induced overexpression of RASAL1 by 5-Aza significantly prohibited cell proliferation and stemness potential of the JAR cell. Additionally, the xenograft model indicated that knockdown of RASAL1 led to a remarkable increase of tumor volume and weight in comparison with its counterpart. Moreover, the stimulatory activity brought by decrease of RASAL1 could be deprived by ß-catenin inhibitor XAV 939, yet the suppressive activity resulted from its promoter demethylation could be rescued by ß-catenin activator BML-284, indicating that function of RASAL1 depends on ß-catenin. Besides, the co-immunoprecipitation assay confirmed the physical binding between RASAL1 and ß-catenin. Further investigations showed hypermethylated RASAL1 was regulated by TET2 but not DNMTs. CONCLUSION: Taken together, the present data elucidated that reduced RASAL1 through its promoter hypermethylation regulated by TET2 promoted the tumorigenicity and chemoresistance of CC via modulating ß-catenin both in vitro and in vivo.

Targeting the long non-coding RNA MIAT for the treatment of fibroids in an animal model.

Our previous studies indicated that there is overexpression of MIAT in fibroids and MIAT is a sponge for the miR-29 family in these tumors. The objective of the present study was to determine if the knockdown of MIAT in fibroid xenografts will increase miR-29 levels and reduce the expression of genes targeted by this miRNA such as collagen and cell cycle regulatory proteins in a mouse model for fibroids. Ovariectomized CB-17 SCID/Beige mice bearing estrogen/progesterone pellets were implanted subcutaneously in the flank with equal weight of fibroid explants which had been transduced by lentivirus for either control (empty vector) or MIAT knockdown for four weeks (n=7). Knockdown of MIAT in fibroid xenografts resulted in a 30% reduction of tumor weight and a marked increase in miR-29a, -b, and -c levels in the xenografts. There was reduced cell proliferation and expression of cell cycle regulatory genes CCND1, CDK2, and E2F1 and no significant changes in apoptosis. The xenografts with MIAT knockdown expressed lower mRNA and protein levels of FN1, COL3A1, and TGF-ß3, and total collagen protein. Targeting MIAT, which sponges the pro-fibrotic miR-29 family, is an effective therapy for fibroids by reducing cell proliferation and thereby, tumor growth and accumulation of ECM, which is a hallmark of these benign gynecologic tumors.

Preclinical in vitro and in vivo activity of the RAF/MEK clamp avutometinib in combination with FAK inhibition in uterine carcinosarcomas.

OBJECTIVES: Uterine carcinosarcomas (UCS) are rare, biologically aggressive tumors. Since UCS may harbor mutations in RAS/MAPK pathway genes we evaluated the preclinical in vitro and in vivo efficacy of the RAF/MEK clamp avutometinib in combination with the focal adhesion kinase (FAK) inhibitors defactinib or VS-4718 against multiple primary UCS cell lines and xenografts. METHODS: Whole-exome-sequencing (WES) was used to evaluate the genetic landscape of 5 primary UCS cell lines. The in vitro activity of avutometinib ± FAK inhibitor was evaluated using cell viability and cell cycle assays against primary UCS cell lines. Mechanistic studies were performed using western blot assays while in vivo experiments were completed in UCS tumor bearing mice treated with avutometinib ± FAK inhibitor by oral gavage. RESULTS: WES results demonstrated multiple UCS cell lines harbor genetic alterations including KRAS, PTK2, BRAF, MAP2K, and MAP2K1, potentially sensitizing to FAK and RAF/MEK inhibition. Four out of five of the UCS cell lines demonstrated in vitro sensitivity to FAK and/or RAF/MEK inhibition when used alone or in combination. By western blot assays, exposure of UCS cell lines to the combination of defactinib/avutometinib demonstrated decreased phosphorylated (p)-FAK as well as decreased p-ERK. In vivo, the combination of avutometinib/VS-4718 demonstrated superior tumor growth inhibition and longer survival compared to single agent treatment and controls starting at day 10 (p < 0.002) in UCS xenografts. CONCLUSION: The combination of avutometinib and defactinib demonstrates promising in vitro and in vivo anti-tumor activity against primary UCS cell lines and xenografts.

High-dose ascorbate exerts anti-tumor activities and improves inhibitory effect of carboplatin through the pro-oxidant function pathway in uterine serous carcinoma cell lines.

OBJECTIVE: Uterine serous carcinoma is a highly aggressive non-endometrioid subtype of endometrial cancer with poor survival rates overall, creating a strong need for new therapeutic strategies to improve outcomes. High-dose ascorbate (vitamin C) has been shown to inhibit cell proliferation and tumor growth in multiple preclinical models and has shown promising anti-tumor activity in combination with chemotherapy, with a favorable safety profile. We aimed to study the anti-tumor effects of ascorbate and its synergistic effect with carboplatin on uterine serous carcinoma cells. METHODS: Cell proliferation was evaluated by MTT and colony formation assays in ARK1, ARK2 and SPEC2 cells. Cellular stress, antioxidant ability, cleaved caspase 3 activity and adhesion were measured by ELISA assays. Cell cycle was detected by Cellometer. Invasion was measured using a wound healing assay. Changes in protein expression were determined by Western immunoblotting. RESULTS: High-dose ascorbate significantly inhibited cell proliferation, caused cell cycle arrest, induced cellular stress, and apoptosis, increased DNA damage, and suppressed cell invasion in ARK1 and SPEC2 cells. Treatment of both cells with 1 mM N-acetylcysteine reversed ascorbate-induced apoptosis and inhibition of cell proliferation. The combination of ascorbate and carboplatin produced significant synergistic effects in inhibiting cell proliferation and invasion, inducing cellular stress, causing DNA damage, and enhancing cleaved caspase 3 levels compared to each compound alone in both cells. CONCLUSIONS: Ascorbate has potent antitumor activity and acts synergistically with carboplatin through its pro-oxidant effects. Clinical trials of ascorbate combined with carboplatin as adjuvant treatment of uterine serous carcinoma are worth exploring.

Raf kinase inhibitor protein expression in smooth muscle tumours of the uterus: a diagnostic marker for leiomyosarcoma?

RESEARCH QUESTION: What is the expression pattern of Raf kinase inhibitory protein (RKIP) in different subtypes of leiomyoma (usual type, cellular, apoplectic or haemorrhagic leiomyoma, leiomyoma with bizarre nuclei and lipoleiomyoma) and leiomyosarcoma specimens, and what is its biological role in leiomyosarcoma cells? DESIGN: Leiomyoma and leiomyosarcoma specimens underwent immunohistochemistry staining. Leiomyosarcoma SK-LMS-1 cell line was RKIP knocked down and RKIP overexpressed, and cell viability, wound healing migration and clonogenicity assays were carried out. RESULTS: A higher immunohistochemical expression of RKIP was observed in bizarre leiomyomas, than in usual-type leiomyomas. Decreased expression was also found in cellular leiomyoma, with generally absent staining in leiomyosarcomas. Upon RKIP expression manipulation in SK-LMS-1 cell line, no major differences were observed in cell viability and migration capacity over time. RKIP knockout, however, resulted in a significant increase in the cell's ability to form colonies (P = 0.011). CONCLUSION: RKIP distinct expression pattern among leiomyoma histotype and leiomyosarcoma, and its effect on leiomyosarcoma cells on colony formation, encourages further studies of RKIP in uterine smooth muscle disorders.

Altered extracellular matrix-related pathways accelerate the transition from normal to prefibroid myometrium in Black women.

BACKGROUND: Black women experience a disproportionate impact of uterine fibroids compared to White women, including earlier diagnosis, higher frequency, and more severe symptoms. The etiology underlying this racial disparity remains elusive. OBJECTIVE: The aim of this study was to evaluate the molecular differences in normal myometrium (fibroid-free uteri) and at-risk myometrium (fibroid-containing uteri) tissues in Black and White women. STUDY DESIGN: We conducted whole-genome RNA-seq on normal and at-risk myometrium tissues obtained from both self-identified Black and White women (not Hispanic or Latino) to determine global gene expression profiles and to conduct enriched pathway analyses (n=3 per group). We initially assessed the differences within the same type of tissue (normal or at-risk myometrium) between races. Subsequently, we analyzed the transcriptome of normal myometrium compared to at-risk myometrium in each race and determined the differences between them. We validated our findings through real-time PCR (sample size range=5-12), western blot (sample size range=5-6), and immunohistochemistry techniques (sample size range=9-16). RESULTS: The transcriptomic analysis revealed distinct profiles between Black and White women in normal and at-risk myometrium tissues. Interestingly, genes and pathways related to extracellular matrix and mechanosensing were more enriched in normal myometrium from Black than White women. Transcription factor enrichment analysis detected greater activity of the serum response transcription factor positional motif in normal myometrium from Black compared to White women. Furthermore, we observed increased expression levels of myocardin-related transcription factor-serum response factor and the serum response factor in the same comparison. In addition, we noted increased expression of both mRNA and protein levels of vinculin, a target gene of the serum response factor, in normal myometrium tissues from Black women as compared to White women. Importantly, the transcriptomic profile of normal to at-risk myometrium conversion differs between Black and White women. Specifically, we observed that extracellular matrix-related pathways are involved in the transition from normal to at-risk myometrium and that these processes are exacerbated in Black women. We found increased levels of Tenascin C, type I collagen alpha 1 chain, fibronectin, and phospho-p38 MAPK (Thr180/Tyr182, active) protein levels in at-risk over normal myometrium tissues from Black women, whereas such differences were not observed in samples from White women. CONCLUSION: These findings indicate that the racial disparities in uterine fibroids may be attributed to heightened production of extracellular matrix in the myometrium in Black women, even before the tumors appear. Future research is needed to understand early life determinants of the observed racial differences.

Evaluation of Combined p57KIP2 Immunohistochemistry and Fluorescent in situ Hybridization Analysis for Hydatidiform Moles Compared with Genotyping Diagnosis.

Immunostaining with p57KIP2 is a widely used diagnostic technique to differentiate complete hydatidiform moles (CHMs) from partial hydatidiform moles (PHM) and non-molar hydropic abortion. However, distinguishing between PHMs and non-molar hydropic abortions using histopathology alone is often challenging. This study aimed to evaluate the technical validity and additional benefits of using fluorescence in situ hybridization (FISH) in combination with p57KIP2 immunostaining to diagnose molar and non-molar conceptuses. The study involved 80 specimens, which underwent genetic diagnosis using short tandem repeat analysis, including 44 androgenetic CHMs, 20 diandric monogynic PHMs, 14 biparental non-molar hydropic abortions, 1 monoandric digynic triploid abortion, and 1 vaginal specimen of gestational trophoblastic neoplasia. Two pathologists independently diagnosed the cases based on morphology and p57KIP2 immunostaining while the clinical information was masked. FISH analysis was performed using 3 probes (CEP17, CEPX, and CEPY), which revealed that all androgenetic CHM and biparental diploid non-molar hydropic abortion specimens were diploid. Among the 20 diandric monogynic PHM cases examined by analyzing short tandem repeat polymorphisms, 18 were triploid, and the remaining 2 were diploid. These two specimens were possibly androgenetic/biparental mosaics based on FISH analysis, where the three-signal ratios counting 50 cells were clearly within the diploid ranges. Eight of the 20 genetic PHMs and 2 of the 14 genetically confirmed non-molar hydropic abortions that were falsely diagnosed based on morphology and immunohistochemistry by at least 1 pathologist were correctly diagnosed as PHM and non-molar hydropic abortion, respectively, by FISH analysis. However, 1 monoandric digynic villus was classified as triploid by FISH analysis, leading to a false PHM diagnosis. In conclusion, the combination of FISH analysis with p57KIP2 immunostaining helps in diagnosing molar and non-molar conceptuses in numerous cases; nevertheless, exceptional cases should be considered.

Molecular Basis of Hydatidiform Moles-A Systematic Review.

Gestational trophoblastic diseases (GTDs) encompass a spectrum of conditions characterized by abnormal trophoblastic cell growth, ranging from benign molar pregnancies to malignant trophoblastic neoplasms. This systematic review explores the molecular underpinnings of GTDs, focusing on genetic and epigenetic factors that influence disease progression and clinical outcomes. Based on 71 studies identified through systematic search and selection criteria, key findings include dysregulations in tumor suppressor genes such as p53, aberrant apoptotic pathways involving BCL-2 (B-cell lymphoma), and altered expression of growth factor receptors and microRNAs (micro-ribose nucleic acid). These molecular alterations not only differentiate molar pregnancies from normal placental development but also contribute to their clinical behavior, from benign moles to potentially malignant forms. The review synthesizes insights from immunohistochemical studies and molecular analyses to provide a comprehensive understanding of GTD pathogenesis and implications for personalized care strategies.

The Effect of Race/Ethnicity and MED12 Mutation on the Expression of Long Non-Coding RNAs in Uterine Leiomyoma and Myometrium.

The objective of this study was to elucidate the expression of long non-coding RNA (lncRNA) in leiomyomas (Lyo) and paired myometrium (Myo) and explore the impact of race and MED12 mutation. Fold change analysis (Lyo/paired Myo) indicated the expression of 63 lncRNAs was significantly altered in the mutated group but not in the non-mutated Lyo. Additionally, 65 lncRNAs exhibited an over 1.5-fold change in the Black but not the White group. Fifteen differentially expressed lncRNAs identified with next-generation sequencing underwent qRT-PCR confirmation. Compared with Myo, the expression of TPTEP1, PART1, RPS10P7, MSC-AS1, SNHG12, CA3-AS1, LINC00337, LINC00536, LINC01436, LINC01449, LINC02433, and LINC02624 was significantly higher, while the expression of ZEB2-AS1, LINC00957, and LINC01186 was significantly lower. Comparison of normal Myo with diseased Myo showed significant differences in the expression of several lncRNAs. Analysis based on race and Lyo MED12 mutation status indicated a significantly higher expression of RPS10P7, SNHG12, LINC01449, LINC02433, and LINC02624 in Lyo from Black patients. The expression of TPTEP1, PART1, RPS10P7, MSC-AS1, LINC00337, LINC00536, LINC01436, LINC01449, LINC02433, and LINC02624 was higher, while LINC01186 was significantly lower in the MED12-mutated group. These results indicate that Lyo are characterized by aberrant lncRNA expression, which is further impacted by race and Lyo MED12 mutation status.

Analysis of Expression of the ANG1, CaSR and FAK Proteins in Uterine Fibroids.

Understanding the molecular factors involved in the development of uterine myomas may result in the use of pharmacological drugs instead of aggressive surgical treatment. ANG1, CaSR, and FAK were examined in myoma and peripheral tissue samples taken from women after myoma surgery and in normal uterine muscle tissue samples taken from the control group. Tests were performed using tissue microarray immunohistochemistry. No statistically significant differences in ANG1 expression between the tissue of the myoma, the periphery, and the normal uterine muscle tissue of the control group were recorded. The CaSR value was reduced in the myoma and peripheral tissue and normal in the group of women without myomas. FAK expression was also lower in the myoma and periphery compared to the healthy uterine myometrium. Calcium supplementation could have an effect on stopping the growth of myomas.

Alpha-fetoprotein producing endometrioid carcinoma arising in an adenomyoma of the uterus.

We report a case of alpha-fetoprotein-producing endometrioid carcinoma (AFP-EC) that originated within an adenomyoma of the uterine corpus. A 76-year-old Japanese woman was incidentally discovered to have a uterine tumor along with multiple lung nodules. Upon surgical removal of the uterus, it was revealed that the tumor was situated within the adenomyoma. The tumor exhibited microfollicular structures and solid growth patterns, with hyaline globules, clear cell glands, and primitive tumor cells. Immunohistochemical analysis indicated the presence of germ cell markers, including AFP, SALL4, and glypican3, leading to final diagnosis of AFP-EC. Histopathologically, AFP-ECs exhibit characteristics similar to those of AFP-producing neoplasms in other organs. Furthermore, a nomenclature issue arises when distinguishing AFP-ECs from yolk sac tumors of the endometrium in older patients due to their shared features. The concept of retrodifferentiation or neometaplasia suggests that "endometrioid carcinoma with yolk sac tumor differentiation" or "endometrioid carcinoma with a primitive phenotype" may serve as more fitting terms for the diverse spectrum of AFP-producing neoplasms in the endometrium. In conclusion, this case underscores the diagnostic challenges posed by AFP-ECs arising from adenomyomas and emphasizes the need for refining the nomenclature and classification of AFP-producing neoplasms within the endometrium.

[TFE3-rearranged perivascular epithelioid cell tumors: a clinicopathological analysis of eight cases].

Objective: To investigate the clinicopathological, immunohistochemical and molecular genetic characteristics of TFE3-rearranged perivascular epithelioid cell tumor (PEComa). Methods: Eight cases of PEComa with TFE3 rearrangement diagnosed in the First Affiliated Hospital of Air Force Medical University from January 2014 to July 2022 were collected. Three were consultation cases and 5 were collected from our hospital; 7 cases were resection specimens and 1 case was a needle biopsy specimen. Routine histolopathological analysis, immunohistochemical staining, fluorescence in situ hybridization (FISH) and the next-generation sequencing were performed. Clinical data were collected and the prognosis was assessed. Results: The 8 patients consisted of 5 females and 3 males with a median age of 45 years (ranged from 25 to 65 years). The tumor location included 1 uterus, 1 liver, 1 urachus, 2 kidneys, 1 abdominal cavity, 1 colon, and 1 retroperitoneum (3 subsequent recurrences in the abdominal cavity, pelvis and ovary, and abdominal cavity, respectively). Morphologically, the tumor cells were uniform and epithelioid with translucent or eosinophilic cytoplasm. They were arranged in nests or sheets, most of which were separated by thin-walled blood vessels. There were no papillary structures, and no overt smooth muscle or fat components. Atypical features were seen in 3 cases, with bizarre nuclei and tumor giant cells. Large areas of necrosis were visible, and mitosis was common (up to 28/50 HPF). Melanin deposition was present in 3 cases. Immunohistochemical staining showed diffuse and strong positivity for TFE3 in 8/8 cases and for HMB45 in 6/8 cases; focal positivity for Cathepsin K and Melan-A in 6/8 cases and for SMA in 2/8 of cases. All cases were negative for CKpan, PAX8 and Desmin. TFE3 gene break-apart was detected by FISH in all 8 cases, 4 of which underwent next-generation sequencing, and it revealed that 2 cases presented with SFPQ::TFE3 fusion, 1 case with ASPSCR1::TFE3 fusion, and 1 case with no chimeric fusion. Seven cases were followed up for 4-94 months. All cases were alive; 4 cases were disease-free, 2 cases showed recurrence, and 1 case had metastasis at initial diagnosis. Conclusions: TFE3-rearranged PEComa has unique histomorphological, immunohistochemical and molecular characteristics. The biological behavior is aggressive, which could lead to recurrence and metastasis, and warrants close clinical follow-up.

NNMT overexpression is an adverse prognostic factor in uterine leiomyosarcoma.

Background/aim: Uterine leiomyosarcomas (uLMS) are extremely rare high-grade tumors with a poor prognosis. Their etiopathogenesis remains largely unknown. The uterus is the most frequent site for LMS. uLMS and uterine leiomyoma (uLM) must frequently be differentiated in patients with a uterine mass. Nicotinamide N-methyltransferase (NNMT), a cytoplasmic protein, is involved in the progression and spread of a variety of cancer types. The expression of NNMT in a mesenchymal malignancy was not examined previously. This study represents the first investigation into NNMT expression in uLMS, uLM and benign uterine myometrium and correlates NNMT overexpression with worse prognosis in uLMS. Materials and methods: The expression of NNMT was investigated by immunohistochemistry on formalin-fixed paraffin-embedded tissue of uLMS in 31 patients, uLM in seven patients and benign myometrial in 31 patients. Results: The expression of NNMT in uLMS was markedly higher than in uLM and normal myometrial tissue (p < 0.001). The expression of NNMT in early stage uLMS was lower than in advanced stage disease (p = 0.034). NNMT expression was an independent prognostic factor in predicting recurrence-free survival in uLMS (p = 0.037). Conclusion: NNMT can aid in the preoperative differentiation of uLMS and uLM. The consequences of NNMT overexpression, such as the activation and inactivation of oncoproteins and tumor suppressor proteins, respectively, as well as the enrichment of the cancer stem cell population, overlap with the major mechanisms responsible for poor prognosis in mesenchymal tumors. NNMT may be investigated further in the context of antitumor treatment in patients with mesenchymal malignancies.

POTENTIAL DIAGNOSTIC BIOMARKERS FOR HUMAN MESENCHYMAL TUMORS, ESPECIALLY LMP2/Β1I AND CYCLIN E1/MIB1 DIFFERENTIAL EXPRESSION: PRUM-IBIO STUDY.

Most mesenchymal tumors found in the uterine corpus are benign tumors; however, uterine leiomyosarcoma is a malignant tumor with unknown risk factors that repeatedly recurs and metastasizes. In some cases, the histopathologic findings of uterine leiomyoma and uterine leiomyosarcoma are similar and surgical pathological diagnosis using excised tissue samples is difficult. It is necessary to analyze the risk factors for human uterine leiomyosarcoma and establish diagnostic biomarkers and treatments. Female mice deficient in the proteasome subunit low molecular mass peptide 2 (LMP2)/ß1i develop uterine leiomyosarcoma spontaneously. MATERIAL AND METHODS: Out of 334 patients with suspected uterine mesenchymal tumors, patients diagnosed with smooth muscle tumors of the uterus were selected from the pathological file. To investigate the expression status of biomarker candidate factors, immunohistochemical staining was performed with antibodies of biomarker candidate factors on thin-cut slides of human uterine leiomyosarcoma, uterine leiomyoma, and other uterine mesenchymal tumors. RESULTS AND DISCUSSION: In human uterine leiomyosarcoma, there was a loss of LMP2/ß1i expression and enhanced cyclin E1 and Ki-67/MIB1 expression. In human uterine leiomyomas and normal uterine smooth muscle layers, enhanced LMP2/ß1i expression and the disappearance of the expression of E1 and Ki-67/MIB1 were noted. The pattern of expression of each factor in other uterine mesenchymal tumors was different from that of uterine leiomyosarcoma. CONCLUSIONS: LMP2/ß1i, cyclin E1, and Ki-67/MIB1 may be candidate factors for biomarkers of human uterine leiomyosarcoma. Further large-cohort clinical trials should be conducted to establish treatments and diagnostics for uterine mesenchymal tumors.