Uterine Endometrial Cancer Research Articles

MECOM and the PRDM gene family in uterine endometrial cancer: bioinformatics and experimental insights into pathogenesis and therapeutic potentials

To elucidate the expression profiles, methylation states, and clinicopathological significance of the PRDM gene family, focusing on the MECOM gene's role in uterine endometrial cancer (UCEC) and its molecular interactions with the TGF-beta signaling pathway. Our methodology combined detailed bioinformatics analyses using UALCAN and GEPIA with in vitro assessments in HEC-1-A cells. Techniques included CRISPR-Cas9 for gene editing and various cellular assays (CCK-8, flow cytometry, Transwell) to evaluate the effects of MECOM on cell proliferation, migration, and apoptosis, alongside Western blot analysis for protein regulation in the TGF-beta pathway. MECOM was upregulated in UCEC tissues, influencing tumor cell behavior significantly. Knockout studies demonstrated reduced proliferation and migration and increased apoptosis, while overexpression showed reverse effects. Mechanistically, MECOM modulated critical proteins within the TGF-beta pathway, impacting cell cycle dynamics and apoptotic processes. The PRDM gene family, particularly MECOM, plays a crucial role in the pathogenesis and progression of UCEC, suggesting its utility as a target for novel therapeutic interventions. Our findings offer valuable insights for future research and potential clinical application in managing uterine endometrial cancer.

Glycolysis-mTORC1 crosstalk drives proliferation of patient-derived endometrial cancer spheroid cells with ALDH activity

Cancer stem cells are associated with aggressive phenotypes of malignant tumors. A prominent feature of uterine endometrial cancer is the activation of the PI3K–Akt–mTOR pathway. In this study, we present variations in sensitivities to a PI3K–Akt–mTORC1 inhibitor among in vitro endometrial cancer stem cell-enriched spheroid cells from clinical specimens. The in vitro sensitivity was consistent with the effects observed in in vivo spheroid-derived xenograft tumor models. Our findings revealed a complementary suppressive effect on endometrial cancer spheroid cell growth with the combined use of aldehyde dehydrogenase (ALDH) and PI3K–Akt inhibitors. In the PI3K–Akt–mTORC1 signaling cascade, the influence of ALDH on mTORC1 was partially channeled through retinoic acid-induced lactate dehydrogenase A (LDHA) activation. LDHA inhibition was found to reduce endometrial cancer cell growth, aligning with the effects of mTORC1 inhibition. Building upon our previous findings highlighting ALDH-driven glycolysis through GLUT1 in uterine endometrial cancer spheroid cells, curbing mTORC1 enhanced glucose transport via GLUT1 activation. Notably, elevated LDHA expression correlated with adverse clinical survival and escalated tumor grade, especially in advanced stages. Collectively, our findings emphasize the pivotal role of ALDH–LDHA–mTORC1 cascade in the proliferation of endometrial cancer. Targeting the interaction between mTORC1 and ALDH-influenced glycolysis holds promise for developing novel strategies to combat this aggressive cancer.

Active Heme Metabolism Suppresses Macrophage Phagocytosis via the TLR4/Type I IFN Signaling/CD36 in Uterine Endometrial Cancer.

Uterine endometrial cancer (UEC) is a common gynecological estrogen-dependent carcinoma, usually accompanied by intermenstrual bleeding. Active heme metabolism frequently plays an increasingly important role in many diseases, especially in cancers. Tumor-associated macrophages (TAMs) are the major population in the immune microenvironment of UEC. However, the roles of heme metabolisms in the crosstalk between UEC cells (UECCs) and macrophages are unclear. In our study, by using TCGA database analysis, integration analysis of the protein-protein interaction (PPI) network and sample RNA transcriptome sequencing were done. The expression level of both heme-associated molecules and iron metabolism-related molecules were measured by quantitative real-time polymerase chain reaction. Heme level detection was done through dehydrohorseradish peroxidase assay. In addition to immunohistochemistry, phagocytosis assay of macrophages, immunofluorescence staining, intracellular ferrous iron staining, as well as enzyme-linked immune sorbent assay were performed. In the study, we verified that heme accumulation in UECCs is apparently higher than in endometrial epithelium cells. Low expression of succinate dehydrogenase B under the regulation of estrogen contributes to over-production of succinate and heme accumulation in UECC. More importantly, excessive heme in UECCs impaired macrophage phagocytosis by regulation of CD36. Mechanistically, this process is dependent on toll-like receptor (TLR4)/type I interferons alpha (IFN Iα) regulatory axis in macrophage. Collectively, these findings elucidate that active heme metabolism of UECCs directly decreases phagocytosis by controlling the secretion of TLR4-mediated IFN Iα and the expression of CD36, and further contributing to the immune escape of UEC.

Impact of MRI radiomic feature normalization for prognostic modelling in uterine endometrial and cervical cancers

Widespread clinical use of MRI radiomic tumor profiling for prognostication and treatment planning in cancers faces major obstacles due to limitations in standardization of radiomic features. The purpose of the current work was to assess the impact of different MRI scanning- and normalization protocols for the statistical analyses of tumor radiomic data in two patient cohorts with uterine endometrial-(EC) (n = 136) and cervical (CC) (n = 132) cancer. 1.5 T and 3 T, T1-weighted MRI 2 min post-contrast injection, T2-weighted turbo spin echo imaging, and diffusion-weighted imaging were acquired. Radiomic features were extracted from within manually segmented tumors in 3D and normalized either using z-score normalization or a linear regression model (LRM) accounting for linear dependencies with MRI acquisition parameters. Patients were clustered into two groups based on radiomic profile. Impact of MRI scanning parameters on cluster composition and prognostication were analyzed using Kruskal–Wallis tests, Kaplan–Meier plots, log-rank test, random survival forests and LASSO Cox regression with time-dependent area under curve (tdAUC) (α = 0.05). A large proportion of the radiomic features was statistically associated with MRI scanning protocol in both cohorts (EC: 162/385 [42%]; CC: 180/292 [62%]). A substantial number of EC (49/136 [36%]) and CC (50/132 [38%]) patients changed cluster when clustering was performed after z-score-versus LRM normalization. Prognostic modeling based on cluster groups yielded similar outputs for the two normalization methods in the EC/CC cohorts (log-rank test; z-score: p = 0.02/0.33; LRM: p = 0.01/0.45). Mean tdAUC for prognostic modeling of disease-specific survival (DSS) by the radiomic features in EC/CC was similar for the two normalization methods (random survival forests; z-score: mean tdAUC = 0.77/0.78; LRM: mean tdAUC = 0.80/0.75; LASSO Cox; z-score: mean tdAUC = 0.64/0.76; LRM: mean tdAUC = 0.76/0.75). Severe biases in tumor radiomics data due to MRI scanning parameters exist. Z-score normalization does not eliminate these biases, whereas LRM normalization effectively does. Still, radiomic cluster groups after z-score- and LRM normalization were similarly associated with DSS in EC and CC patients.

The consistent anti-cancer effect of a simple exercise (Ou MC decrescendo phenomenon exercise) may hold promise for low-cost cancer prevention.

The causal relationship between physical activity and anti-cancer effect are not proved by the current studies. However, Ou MC decrescendo phenomenon treatment (OuDPt), a simple exercise treatment, has shown consistent anti-cancer effects, which evinces the consequent anti-cancer effect by physical activity. The anti-cancer effects through OuDPt in the context of physical activity and human body anatomical axes showed to induce apoptosis, restore apical-basal polarity of cancer cells and mitigate epithelial-mesenchymal transition (EMT) with concomitant clinical regression of uterine endometrial cancer, suppression of ovarian and pancreatic cancer growth, regression of early suspicious pancreatic cancer, enhancement of chemotherapy effect of pancreatic cancer and cessation of cancer-related bleeding, which underlines the most important anti-cancer mechanisms. Although such anti-cancer effects by OuDPt show insufficient efficacy for advanced cancer in long-term treatment, OuDPt may be availed as an Ou MC decrescendo phenomenon exercise for cancer prevention. Further study is warranted.

From Infection to Malignancy: Tracing the Impact of Human Papillomavirus on Uterine Endometrial Cancer in a Nationwide Population-Based Cohort Study.

Uterine endometrial cancer (EC) is the most common gynecological malignancy in Taiwan. This study aimed to investigate the association between human papillomavirus (HPV) infection and the development of uterine EC among Taiwanese women. A nationwide population cohort research approach was employed, leveraging longitudinal health insurance databases (LHID 2007 and 2015) from the National Health Insurance Research Database alongside data from the Taiwan Cancer Registry datasets. A comparative analysis examined 472,420 female patients with HPV infection and 944,840 without HPV infection. The results demonstrated that the HPV cohort exhibited a significantly elevated risk of uterine EC, as evidenced by an adjusted hazard ratio (aHR) of 1.588 (95% CI: 1.335-1.888). Furthermore, this elevated risk extended to type 1 EC with an aHR of 1.671 (95% CI: 1.376-2.029), specifically the endometrioid adenocarcinoma subtype with an aHR 1.686 (95% CI: 1.377-2.065). Importantly, these findings were statistically significant (p < 0.001). In conclusion, this research unveils a potential association between HPV infection and an increased risk of uterine EC, particularly the type 1 endometrial cancer subtype, within the Taiwanese female population. These findings have implications for preventive measures and screening programs targeting HPV infection to reduce the risk of this prevalent gynecological malignancy in Taiwan.

Oscillating Gradient Diffusion-Weighted MRI for Risk Stratification of Uterine Endometrial Cancer.

Oscillating gradient diffusion-weighted imaging (DWI) enables elucidation of microstructural characteristics in cancers; however, there are limited data to evaluate its utility in patients with endometrial cancer. To investigate the utility of oscillating gradient DWI for risk stratification in patients with uterine endometrial cancer compared with conventional pulsed gradient DWI. Retrospective. Sixty-three women (mean age: 58 [range: 32-85] years) with endometrial cancer. 3 T MRI including DWI using oscillating gradient spin-echo (OGSE) and pulsed gradient spin-echo (PGSE) research sequences. Mean value of the apparent diffusion coefficient (ADC) values for OGSE (ADCOGSE) and PGSE (ADCPGSE) as well as the ADC ratio (ADCOGSE/ADCPGSE) within endometrial cancer were measured using regions of interest. Prognostic factors (histological grade, deep myometrial invasion, lymphovascular invasion, International Federation of Gynecology and Obstetrics [FIGO] stage, and prognostic risk classification) were tabulated. Interobserver agreement was analyzed by calculating the intraclass correlation coefficient. The associations of ADCOGSE, ADCPGSE, and ADCOGSE/ADCPGSE with prognostic factors were examined using the Kendall rank correlation coefficient, Mann-Whitney U test, and receiver operating characteristic (ROC) curve. A P value of <0.05 was statistically significant. Compared with ADCOGSE and ADCPGSE, ADCOGSE/ADCPGSE was significantly and strongly correlated with histological grade (observer 1, τ = 0.563; observer 2, τ = 0.456), FIGO stage (observer 1, τ = 0.354; observer 2, τ = 0.324), and prognostic risk classification (observer 1, τ = 0.456; observer 2, τ = 0.385). The area under the ROC curves of ADCOGSE/ADCPGSE for histological grade (observer 1, 0.92, 95% confidence intervals [CIs]: 0.83-0.98; observer 2, 0.84, 95% CI: 0.73-0.92) and prognostic risk (observer 1, 0.80, 95% CI: 0.68-0.89; observer 2, 0.76, 95% CI: 0.63-0.86) were significantly higher than that of ADCOGSE and ADCPGSE. The ADC ratio obtained via oscillating gradient and pulsed gradient DWIs might be useful imaging biomarkers for risk stratification in patients with endometrial cancer. 3 TECHNICAL EFFICACY: Stage 2.

The Causal Relationship of Anti-Cancer Effect with Physical Activity Evinced by the Consistent Anti-Cancer Effect of the Ou MC Decrescendo Phenomenon.

A causal relationship between physical activity and cancer prevention has not been firmly established in the medical literature. The Ou MC decrescendo phenomenon treatment (OuDPt) is a self-administered protocol in which placing the contralateral hand on or near the affected area of the body produces a zone of decreased pain or inflammation. OuDPt has also been shown to elicit an anti-cancer effect that consistently induces tumor regression in several cancer types, including uterine, ovarian, and pancreatic cancer, with documented apoptosis and squamous metaplasia in uterine endometrial cancer. The anti-cancer effects of OuDPt are associated with factors such as the frequency, duration, and intensity of treatment, as well as the accessibility and susceptibility of the tumor. This relationship mirrors the dynamics between antibiotics and bacterial infections, where similar factors come into play. Given that OuDPt is self-administered and easy to perform, and produces consistent anti-cancer effects, this procedure could be potentially harnessed for cancer prevention. Further study of the use of OuDPt for cancer prevention is warranted.

Active Estrogen-Succinate Metabolism Promotes Heme Accumulation and Increases the Proliferative and Invasive Potential of Endometrial Cancer Cells.

Uterine endometrial cancer (UEC) is an estrogen-related tumor. Succinate and heme metabolism play important roles in the progression of multiple tumors. However, the relationship between estrogen, succinate, and heme metabolism and related regulatory mechanisms remain largely unknown. In this study, we observed that the expression of aminolevulinate delta synthase 1 (ALAS1) and solute carrier family member 38 (SLC25A38) in UEC tissues is significantly higher than that in normal tissues. Further analysis showed that estrogen and succinate increased the expression of ALAS1 and SLC25A38 in uterine endometrial cancer cells (UECC), and the administration of succinate upregulated the level of the estrogen receptor (ER). Silencing nuclear receptor coactivator 1 (NCOA1) reversed the effects of estrogen and succinate via downregulation of ALAS1 expression. Additionally, exposure of UECC to heme increased cell viability and invasiveness, while silencing the NCOA1 gene weakened this effect. These findings revealed that estrogen and succinate can synergistically increase the expression of ALAS1 and SLC25A38 via the ERβ/NCOA1 axis, promoting heme accumulation and increasing the proliferative and invasive potential of UECC.

Using cancer proteomics data to identify gene candidates for therapeutic targeting.

Gene-level associations obtained from mass-spectrometry-based cancer proteomics datasets represent a resource for identifying gene candidates for functional studies. When recently surveying proteomic correlates of tumor grade across multiple cancer types, we identified specific protein kinases having a functional impact on uterine endometrial cancer cells. This previously published study provides just one template for utilizing public molecular datasets to discover potential novel therapeutic targets and approaches for cancer patients. Proteomic profiling data combined with corresponding multi-omics data on human tumors and cell lines can be analyzed in various ways to prioritize genes of interest for interrogating biology. Across hundreds of cancer cell lines, CRISPR loss of function and drug sensitivity scoring can be readily integrated with protein data to predict any gene's functional impact before bench experiments are carried out. Public data portals make cancer proteomics data more accessible to the research community. Drug discovery platforms can screen hundreds of millions of small molecule inhibitors for those that target a gene or pathway of interest. Here, we discuss some of the available public genomic and proteomic resources while considering approaches to how these could be leveraged for molecular biology insights or drug discovery. We also demonstrate the inhibitory effect of BAY1217389, a TTK inhibitor recently tested in a Phase I clinical trial for the treatment of solid tumors, on uterine cancer cell line viability.

Secondary Adrenal Insufficiency Due to Isolated ACTH Deficiency Induced by Pembrolizumab: A Report of Two Cases of Uterine Endometrial Cancer

Immune checkpoint inhibitors (ICIs) enhance antitumoral immune mechanisms and are used to treat various types of solid tumors including those that are microsatellite instability (MSI)-high. Uterine endometrial cancer is one of the most frequent tumor types that shows MSI-high, and, consequently, opportunities to use ICIs for endometrial cancer treatment are increasing. While using ICIs, it is important to monitor and manage various immune-related adverse events (irAEs). Here, we report two cases of secondary adrenal insufficiency during treatment of endometrial cancer with pembrolizumab. Both cases showed appetite loss and general fatigue after the 6th or 12th cycle of pembrolizumab. They were admitted to our hospital because of remarkable hyponatremia. Both cases showed no adrenocorticotropic hormone (ACTH) or cortisol response to CRH loading tests. Other pituitary hormone levels were normal, and MRI revealed no sign of hypophysitis in either patient. They were diagnosed with secondary adrenal insufficiency due to isolated ACTH deficiency and recovered soon after the administration of hydrocortisone and hydration. Thus, we should be aware of irAEs with the use of ICIs. In particular, adrenocortical insufficiency is sometimes lethal without appropriate treatment. Because the clinical symptoms are fatigue, appetite loss, and nausea, patients might be misjudged to have symptoms related to cancer. Checking serum morning cortisol before ICIs use and monitoring serum sodium levels could provide clues to diagnose secondary adrenal insufficiency.

Pattern of practice for postoperative management of endometrial cancer in Korea: a survey by the Korean Gynecologic Oncology Group and the Korean Radiation Oncology Group (KGOG 2028-KROG 2104).

This study aimed to investigate the current status of postoperative management of uterine endometrial cancer (EC) in Korea. A mail survey was administered to members of the Korean Gynecologic Oncology Group and Korean Radiation Oncology Group. A total of 38 gynecologic cancer surgeons (GYNs) and 31 radiation oncologists (RO) in 43 institutions was responded. The questionnaire consisted of general questions for clinical decision and clinical case questions. The GYN and RO responses were compared using chi-square statistics. The 2 expert groups had similar responses for clinical decision based on the results of the Gynecologic Oncology Group (GOG)-249 and Postoperative Radiation Therapy for Endometrial Carcinoma-III trials in the early-stage EC. In contrast, the responses based on GOG-258 results differed, as GYNs most frequently opted for sequential chemotherapy (CTx) and radiotherapy (RT), while ROs preferred concurrent chemoradiotherapy in locally advanced stage (p<0.05). Based on the GOG-258, GYNs preferred CTx alone for adjuvant treatment of serous or clear cell adenocarcinoma histology, whereas ROs advocated for combined CTx and RT (sequential or concurrent). Among the clinical case questions, GYNs were more likely than ROs to choose CTx alone rather than the combination of CTx and RT (sequential or concurrent) as the answers to case questions representing patients with locally advanced stage or unfavorable histology (all p<0.05). The present study showed several different opinions of GYNs and ROs regarding adjuvant treatment for EC, particularly for adjuvant RT in advanced stage or unfavorable histology.

Genistein induces long-term expression of progesterone receptor regardless of estrogen receptor status and improves the prognosis of endometrial cancer patients

Progesterone is used to treat uterine endometrial cancer in young patients wishing to preserve their fertility as well as in advanced or recurrent patients, but its response rate is limited. The antitumor effect of progesterone is mediated by progesterone receptor (PR) binding. Hence, loss of progesterone’s therapeutic effect, i.e., development of progesterone resistance, is mainly due to decreased PR expression. However, little is known about underlying mechanisms that regulate PR expression. Immunohistochemistry analysis of specimens from 31 young, endometrial cancer patients showed that elevated PR expression significantly increased (P < 0.05) rates of progression-free and overall survival. We investigated mechanisms of regulating PR expression and suppressing cell proliferation using genistein, a chemotherapeutic agent against different cancers. Genistein inhibits cell growth by inducing cell cycle arrest in G2 and apoptosis; moreover, it upregulates prolonged expression of PR-B and forkhead box protein O1, regardless of estrogen receptor alpha expression in endometrial cancer cells. Genistein-induced PR expression decreases CCAAT/enhancer binding protein beta expression and activates c-Jun N-terminal kinase pathway, rather than causing epigenetic alterations of the PR promoter. Therefore, increased PR expression is an important antitumor effect of genistein. This may help to improve the response rates of fertility-sparing treatments for young patients.

Ezrin Regulates the Cell Surface Localization of PD-L1 in HEC-151 Cells.

Programmed death ligand-1 (PD-L1) is an immune checkpoint molecule widely expressed on the surface of cancer cells and is an attractive immunotherapeutic target for numerous cancer cell types. However, patients with endometrial cancer derive little clinical benefit from immune checkpoint blockade therapy because of their poor response rate. Despite the increasingly important function of PD-L1 in tumor immunology, the mechanism of PD-L1 localization on endometrial cancer cell surfaces is largely unknown. We demonstrated the contribution of the ezrin, radixin, and moesin (ERM) family, which consists of scaffold proteins that control the cell surface localization of several transmembrane proteins to the localization of PD-L1 on the cell surface of HEC-151, a human uterine endometrial cancer cell line. Confocal immunofluorescence microscopy and immunoprecipitation analysis revealed the colocalization of all the ERM with PD-L1 on the cell surface, as well as their protein–protein interactions. The RNA-interference-mediated knockdown of ezrin, but not radixin and moesin, significantly reduced the cell surface expression of PD-L1, as measured by flow cytometry, with little impact on the PD-L1 mRNA expression. In conclusion, among the three ERM proteins present in HEC-151 cells, ezrin may execute the scaffold function for PD-L1 and may be mainly responsible for the cell surface localization of PD-L1, presumably via the post-translational modification process.

ARID1A loss-of-function induces CpG island methylator phenotype

The CpG island methylator phenotype (CIMP) is associated with prognosis and drug sensitivity in multiple cancer types. In gastric cancer, the CIMP is closely associated with Epstein-Barr virus (EBV) infection and AT-rich interactive domain 1A (ARID1A) mutations, a component of the SWI/SNF chromatin remodeling complex. However, the involvement of SWI/SNF defects in CIMP induction has been unclear. In this study, we demonstrate a causal role of ARID1A loss-of-function in CIMP induction. Mutations of SWI/SNF components, especially ARID1A, was associated with the CIMP, as well as EBV infection, in gastric cancers, and also in uterine endometrial and colorectal cancers, which are not affected by EBV infection. Genome-wide DNA methylation analysis showed that ARID1A knockout (KO) in cultured 293FT cells and gastric epithelial cells, GES1, induced aberrant DNA methylation of a substantial number of CpG sites. DNA methylation was induced at genomic regions with high levels of pre-existing histone H3 lysine 27 trimethylation (H3K27me3) and those with acquired H3K27me3 by ARID1A KO. These results showed that the ARID1A mutation induced aberrant DNA methylation, and this is likely to be one of the potential mechanisms of CIMP induction.

Clinical issues of surgery for uterine endometrial cancer in Japan.

The mainstay of treatment for uterine endometrial cancer is surgery, and recurrent-risk cases require multidisciplinary treatment, including surgery, chemotherapy and radiation therapy. The standard surgery for uterine endometrial cancer is hysterectomy and bilateral salpingooophorectomy, with additional retroperitoneal lymph node dissection and omentectomy, depending on the case. The appropriate treatment is determined based on the risk classification, such as the depth of invasion into the myometrium, diagnosis of histological type and grade, and risk assessment of lymph node metastasis. Recently, minimally invasive surgery has been widely used not only in low-risk patients but also in intermediate- and high-risk patients. In low-risk patients, the possibility of ovarian preservation is discussed from a healthcare perspective for young women. Determining the need for retroperitoneal lymph node dissection based on sentinel lymph node evaluation may contribute in minimizing the incidence of post-operative lymphedema while ensuring accurate diagnosis of lymph node metastasis. Recently, many studies using sentinel lymph nodes have been reported for patients with uterine endometrial cancer, and the feasibility of sentinel lymph node mapping surgery has been proven. Unfortunately, sentinel lymph node biopsy and sentinel lymph node mapping surgery have not been widely adopted in surgery for uterine cancer in Japan. In addition, the search for biomarkers, such as RNA sequencing using The Cancer Genome Atlas, metabolic profile and lipidomic profile for early detection and prognostic evaluation, has been actively pursued. Gynecologic oncologists expect to be able to provide uterine endometrial cancer patients with appropriate treatment that preserves their quality of life without compromising oncologic outcomes in the near future.

A case of laparoscopic total hysterectomy for uterine endometrial cancer in a patient with severe obesity and a giant thyroid tumor

A case of laparoscopic total hysterectomy for uterine endometrial cancer in a patient with severe obesity and a giant thyroid tumor

Elevated Enhancer-Oncogene Contacts and Higher Oncogene Expression Levels By Recurrent CTCF inactivating Mutations in T Cell Acute Lymphoblastic Leukemia

Introduction. The CCCTC-binding factor (CTCF) regulates the 3D chromatin architecture by facilitating chromosomal loops and forming the boundaries of structural domains. In addition, CTCF is an important transcription factor and regulator of antigen receptor and T cell receptor recombination events. CTCF inactivating events have been found in various human cancers. Loss-of-heterozygosity (LOH) or inactivating missense mutations in specific zinc- fingers have been identified in many human cancers including sporadic breast cancer, prostate cancer, Wilms-tumors and acute lymphoblastic leukemia (ALL). Heterozygous deletions or point mutations have been identified in over half of the patients with breast cancer or uterine endometrial cancers, deregulating global gene expression by altering methylated genomic states and poor survival. Here, we investigated the functional significance and molecular-cytogenetic associations of CTCF aberrations in T-cell acute lymphoblastic leukemia patients.Methods. Biopsies from a cohort of 181 pediatric T-ALL patients who enrolled on DCOG or COALL protocols and/or their derivative patient-derived xenograft models were screened for alterations in global DNA copy number, methylation status, topologically associating domain organization and CTCF and cohesion binding patterns and changes in local TLX3 and BCL11B promoter enhancer loops using array-comparative genomic hybridization, single molecule Molecular Inversion Probe sequencing, targeted locus amplification, gene expression and DNA methylation microarrays, Hi-C sequencing, Chromatin Immunoprecipitation and/or real-time quantitative PCR. Ctcf f/fl mice 1 were crossed on a the Lck-cre transgenic background 2 to study the impact of Ctcf loss during early T-cell development.Results. We here describe that inactivation of CTCF can drive subtle and local genomic effects that elevate oncogene expression levels from driver chromosomal rearrangements. We find that for T cell acute lymphoblastic leukemia (T-ALL), heterozygous CTCF deletions or inactivating mutations are present in nearly 50 percent of t(5;14)(q35;q32.2) rearranged patients that positions the TLX3 oncogene in the vicinity of the BCL11B enhancer. Functional CTCF loss results in diminished expression of the αβ-lineage commitment factor BCL11B from the non-rearranged allele and γδ-lineage development. Unexpectedly, it also drives higher levels of the TLX3 oncogene from the translocated allele. We demonstrate that heterozygous CTCF aberrations specifically occur in TLX3-rearranged patients with distal breakpoints that preserve CTCF bindings sites in the translocation breakpoint areas in between the BCL11B enhancer and the TLX3 oncogene. We show that these intervening CTCF sites insulate TLX3 from the enhancer by forming competitive loops with TLX3. Upon loss of CTCF, or the deletion of the intervening CTCF sites, these competitive loops are weakened and loops with the BCL11B enhancer are stimulated, boosting TLX3 oncogene expression levels and leukemia burden in these T-ALL patients.Conclusions. CTCF aberrations are especially associated with t(5;14)(q35;q32.2) rearranged T-ALL patients who maintain TLX3-proximal CTCF sites reflects a necessity to neutralize these sites in order to topologically enable the distal BCL11B enhancer to interact with the TLX3 oncogene and to boost its expression. Collectively, this provides direct demonstration of a mechanism in which loss of CTCF result in removal of enhancer insulation that facilitates elevated levels of an oncogene in leukemia.References.1. Heath H, Ribeiro de Almeida C, Sleutels F, et al. CTCF regulates cell cycle progression of alphabeta T cells in the thymus. EMBO J. 2008;27(21):2839-2850.2. Lee PP, Fitzpatrick DR, Beard C, et al. A critical role for Dnmt1 and DNA methylation in T cell development, function, and survival. Immunity. 2001;15(5):763-774. DisclosuresSplinter: Cergentis BV: Current Employment. Van Eyndhoven: Agilent Technologies Netherland: Current Employment. Van Min: Cergentis BV: Current Employment. Mullighan: Pfizer: Research Funding; Illumina: Membership on an entity's Board of Directors or advisory committees; AbbVie: Research Funding; Amgen: Current equity holder in publicly-traded company.

Automatic segmentation of uterine endometrial cancer on multi-sequence MRI using a convolutional neural network

Endometrial cancer (EC) is the most common gynecological tumor in developed countries, and preoperative risk stratification is essential for personalized medicine. There have been several radiomics studies for noninvasive risk stratification of EC using MRI. Although tumor segmentation is usually necessary for these studies, manual segmentation is not only labor-intensive but may also be subjective. Therefore, our study aimed to perform the automatic segmentation of EC on MRI with a convolutional neural network. The effect of the input image sequence and batch size on the segmentation performance was also investigated. Of 200 patients with EC, 180 patients were used for training the modified U-net model; 20 patients for testing the segmentation performance and the robustness of automatically extracted radiomics features. Using multi-sequence images and larger batch size was effective for improving segmentation accuracy. The mean Dice similarity coefficient, sensitivity, and positive predictive value of our model for the test set were 0.806, 0.816, and 0.834, respectively. The robustness of automatically extracted first-order and shape-based features was high (median ICC = 0.86 and 0.96, respectively). Other high-order features presented moderate-high robustness (median ICC = 0.57–0.93). Our model could automatically segment EC on MRI and extract radiomics features with high reliability.

Abstract 2502: Co-existing P53 and ARID1A mutations promote metastatic endometrial tumorigenesis

Abstract P53 and ARID1A are frequently mutated across cancer but rarely in the same tumor. Uterine endometrial cancer displays the highest P53-ARID1A mutual exclusivity rate. The genetic basis underlying P53-ARID1A mutual exclusivity and the relationship between molecular programs imposed by either mutation have not been elucidated in vivo mouse models. Here, genetically engineered mice were used to discern both unique and overlapping roles of P53 and ARID1A in the endometrium. Endometrial epithelial hyperplasia is driven by P53 loss with oncogenic PIK3CAH1047R in the endometrial epithelium. Sorted hyperplastic endometrial epithelial cells were transcriptome profiled and compared to control cells and ARID1A-PIK3CA mutant endometrium. Both P53 and ARID1A mutations lead to activation of inflammatory pathways but differ on other gene expression programs, such as epithelial-to-mesenchymal transition. Gene expression patterns observed in the genetic mouse models are reflective of human tumors with respective genetic alterations. ARID1A co-regulates P53 transcriptional gene targets, and the P53 pathway is activated in ARID1A mutant endometrial tumors. Finally, TP53 and ARID1A mutations co-occur more frequently in metastatic lesions, and co-existing TP53-ARID1A mutations are viable in the endometrium and lead to invasive endometrial cancer. These data suggest P53 and ARID1A mutations stimulate shared and distinct tumorigenic programs in the endometrium and promote metastasis when existing simultaneously. We propose that ARID1A loss in P53 mutant endometrial cancer promotes metastasis. Citation Format: Jake J. Reske, Mike R. Wilson, Jeanne Holladay, John I. Risinger, Ronald L. Chandler. Co-existing P53 and ARID1A mutations promote metastatic endometrial tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2502.