Intratumour heterogeneity in endometrial serous carcinoma assessed by targeted sequencing and multiplex ligation-dependent probe amplification: a descriptive study.

AIMS: Endometrial serous carcinoma (ESC) represents the most aggressive subtype of endometrial carcinoma (EC). According to The Cancer Genome Atlas (TCGA), ESC exhibits a genomic profile characterised by frequent TP53 mutations and somatic copy-number alterations (SCNA). Several studies have suggested the role of intratumour heterogeneity (ITH) in tumour progression and therapy resistance, highlighting ITH as a challenge for personalised medicine. ITH is described as the co-existence of clonal and subclonal cellular populations within a single tumour. To date, the extent and prevalence of ITH in ESC have not been fully evaluated. The aim of this study was to address ITH analysis in ESC. We performed a descriptive integrated molecular approach using targeted sequencing and multiplex ligation-dependent probe amplification (MLPA) to identify mutations and SCNA patterns, respectively. METHODS AND RESULTS: Eight ESC were examined, selecting three tumour regions per case and their corresponding normal tissue. For targeted sequencing a gene panel of 40 genes based on TCGA and other survey data was performed. For MLPA different probe mixes were used to detect SCNA in 106 genes. Analysis of mutations and SCNA were performed in each sample and comparative analysis of the three tumour regions was also conducted. Targeted sequencing showed that mutations in TP53, PIK3CA and PPP2R1A were ubiquitous in all tumour regions. Moreover, MLPA results demonstrated a high frequency of SCNA, according to the already known presence of genomic instability in ESC. Unlike the homogeneous distribution of somatic mutations, SCNA exhibited ITH affecting targetable genes such as ERBB2. CONCLUSIONS: Our study suggests that somatic gene copy-number alterations are the main source of ITH in ESC.

Tumor suppressive function of E2F-1 on PTEN-induced serrated colorectal carcinogenesis.

Many human cancers present Phosphatase and tensin homolog (PTEN) deficiency and between 20 and 30% of colorectal tumors show PTEN loss. The transcription factor, E2 promoter binding factor 1 (E2F-1), exhibits tumor promoter or suppressive functions depending on cellular type and tissue context, but its role in the progression and development of colorectal carcinogenesis was largely unknown. Here, using a tamoxifen-inducible PTEN knockout mouse model, we have demonstrated that loss of PTEN leads to the development of colorectal tumorigenesis through the serrated pathway. Next, we studied PTEN loss-driven colorectal lesions in the context of E2F-1 deficiency in vivo. Our results revealed that monoallelic and biallelic absence of E2F-1 led to an increased incidence and progression of serrated tumorigenesis induced by PTEN loss. Finally, we investigated the mechanisms by which double PTEN/E2F-1 deficiency leads to enhanced tumorigenesis. We found that colorectal tumors from PTEN/E2F-1 double knockout mice and the human colorectal carcinoma cell line HT29 with shRNA-mediated downregulation of PTEN and E2F-1 exhibit hyperactivation of the RAS-MAPK pathway, accumulation of DNA damage and resistance to apoptosis. To date, this is the first preclinical study evaluating the effect of genetic deletion of E2F-1 in colorectal malignancies driven by PTEN deficiency. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Therapeutic potential of the new TRIB3-mediated cell autophagy anticancer drug ABTL0812 in endometrial cancer.

OBJECTIVES: The PI3K/AKT/mTOR pathway is frequently overactivated in endometrial cancer (EC). We assessed the efficacy of ABTL0812, a novel first-in-class molecule presenting a unique mechanism of action inhibiting this pathway. METHODS: We investigated the effects of ABTL0812 on proliferation, cell death and modulation of intracellular signaling pathways in a wide panel of endometrioid and non-endometrioid cell lines, an inducible PTEN knock-out murine model, and two patient-derived xenograft murine models of EC. Then, TRIB3 expression was evaluated as potential ABTL0812 pharmacodynamic biomarker in a Phase 1b/2a clinical trial. RESULTS: ABTL0812 induced an upregulation of TRIB3 expression, resulting in the PI3K/AKT/mTOR axis inhibition and autophagy cell death induction on EC cells but not in healthy endometrial cells. ABTL0812 treatment also impaired PTEN knock-out cells to progress from hyperplasia to cancer. The therapeutic effects of ABTL0812 were demonstrated in vivo. ABTL0812 increased TRIB3 mRNA levels in whole blood samples of eight EC patients, demonstrating that TRIB3 mRNA could be used as a pharmacodynamic biomarker to monitor the ABTL0812 treatment. CONCLUSIONS: ABTL0812 may represent a novel and highly effective therapeutic agent by inducing TRIB3 expression and autophagy in EC patients, including those with poorer prognosis.

Deletion of Pten in CD45-expressing cells leads to development of T-cell lymphoblastic lymphoma but not myeloid malignancies.

Since its discovery in the late 1990s, Pten has turned out to be one of the most important tumor suppressor genes. Pten loss results in increased activation of the phosphatidylinositol 3-kinase/Akt signaling pathway, which is associated with increased proliferation, survival, and neoplastic growth. Here, we have addressed the effects of conditional deletion of Pten in hematopoietic cells by crossing Pten conditional knockout mice with a knock-in mouse expressing the Cre recombinase in the CD45 locus. CD45 is also known as leukocyte common antigen, and it is expressed in virtually all white cells and in hematopoietic stem cells. Using a reporter mouse, we demonstrate that CD45:Cre mouse displays recombinase activity in both myeloid and lymphoid cells. However, deletion of Pten in CD45-expressing cells induces development of T-cell acute lymphoblastic leukemia and lymphoma, but not other hematologic malignancies.

Tumor Heterogeneity in Endometrial Carcinoma: Practical Consequences.

Endometrial carcinoma (EC) shows intertumor heterogeneity, with several different histologic types differing in their morphologic and molecular features. There is also intratumoral morphologic heterogeneity, with different neoplastic cell components within the same tumor, with different morphologic and molecular features. In this article, we discuss the consequences of tumor heterogeneity in EC at the morphologic and molecular levels, by describing some illustrative examples produced by the research team. They are (1) morphologic heterogeneity in conventional EC and mixed tumors, (2) EC with microsatellite instability, (3) branched evolution as shown by exome sequencing analysis, (4) morphologic, molecular, and metabolomic differences between the tumor surface and myometrial invasion front, (5) tumor heterogeneity at the microenviromental level, (6) the sensitivity of endometrial aspirates to detect tumor heterogeneity in EC, and (7) sampling strategies to detect tumor heterogeneity in hysterectomy specimens. Tumor heterogeneity may have an important clinical impact, since it can be challenging to identify minor tumor cell populations that may have an impact on diagnosis, prognosis, and therapeutic decisions for patients with EC.

Palbociclib has antitumour effects on Pten-deficient endometrial neoplasias.

PTEN is one of the most frequently mutated genes in human cancers. The frequency of PTEN alterations is particularly high in endometrial carcinomas. Loss of PTEN leads to dysregulation of cell division, and promotes the accumulation of cell cycle complexes such as cyclin D1-CDK4/6, which is an important feature of the tumour phenotype. Cell cycle proteins have been presented as key targets in the treatment of the pathogenesis of cancer, and several CDK inhibitors have been developed as a strategy to generate new anticancer drugs. Palbociclib (PD-332991) specifically inhibits CDK4/6, and it has been approved for use in metastatic breast cancer in combination with letrazole. Here, we used a tamoxifen-inducible Pten knockout mouse model to assess the antitumour effects of cyclin D1 knockout and CDK4/6 inhibition by palbociclib on endometrial tumours. Interestingly, both cyclin D1 deficiency and palbociclib treatment triggered shrinkage of endometrial neoplasias. In addition, palbociclib treatment significantly increased the survival of Pten-deficient mice, and, as expected, had a general effect in reducing tumour cell proliferation. To further analyse the effects of palbociclib on endometrial carcinoma, we established subcutaneous tumours with human endometrial cancer cell lines and primary endometrial cancer xenografts, which allowed us to provide more translational and predictive data. To date, this is the first preclinical study evaluating the response to CDK4/6 inhibition in endometrial malignancies driven by PTEN deficiency, and it reveals an important role of cyclin D-CDK4/6 activity in their development. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Oral intake of genetically engineered high-carotenoid corn ameliorates hepatomegaly and hepatic steatosis in PTEN haploinsufficient mice.

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease. Here we show that a mouse model of haploinsufficiency in the lipid and protein phosphatase and tensin homolog protein (PTEN(+/-)) exhibits hepatomegaly, increased liver lipogenic gene expression (SREBP-1C and PPARγ) and hepatic lesions analogous to human NAFLD. The livers of PTEN(+/-) mice also contained lower levels of retinoic acid (RA) than normal, similarly to human NAFLD patients. The RA signaling pathway thus offers a novel therapeutic target for the treatment of NAFLD although the impact of nutrition in this context is unclear. We therefore fed PTEN(+/-) mice for 36weeks a diet containing genetically engineered high-carotenoid corn (HCAR) to investigate its potential beneficial effects on the hepatic symptoms of NAFLD. The HCAR diet reduced hepatomegaly and promoted the repartitioning of fatty acids in the liver, away from triacylglycerol storage. At the molecular level, the HCAR diet clearly reduced lipogenic gene expression, boosted catabolism, and increased hepatic RA levels. These results set the stage for human trials to evaluate the use of high-carotenoid foods for the reduction or prevention of steatosis in NAFLD.

Endometrial Carcinoma: Specific Targeted Pathways.

Endometrial cancer (EC) is the most common gynecologic malignancy in the western world with more than 280,000 cases per year worldwide. Prognosis for EC at early stages, when primary surgical resection is the most common initial treatment, is excellent. Five-year survival rate is around 70 %.Several molecular alterations have been described in the different types of EC. They occur in genes involved in important signaling pathways. In this chapter, we will review the most relevant altered pathways in EC, including PI3K/AKT/mTOR, RAS-RAF-MEK-ERK, Tyrosine kinase, WNT/ß-Catenin, cell cycle, and TGF-ß signaling pathways. At the end of the chapter, the most significant clinical trials will be briefly discussed.This information is important to identify specific targets for therapy.

Modeling glands with PTEN deficient cells and microscopic methods for assessing PTEN loss: endometrial cancer as a model.

PTEN is an important tumor suppressor gene. Interpreting PTEN deficiency in the appropriate microscopic context of cancer may be important to understand its role in tumor development and progression. This may be particularly relevant in heterogeneous tumors. Here, we discuss the usefulness of 3D cultures in understanding the consequences of PTEN inactivation in tissue architecture. Afterwards, we discuss the role of immunohistochemistry and fluorescent in situ hybridization in assessing PTEN loss in tumors. In this review, endometrial carcinoma is used as a model.

ETV5 transcription program links BDNF and promotion of EMT at invasive front of endometrial carcinomas.

Myometrial infiltration represents a main clinical determinant of endometrial carcinomas (EC) presenting as aggressive high-grade deeply invasive neoplasms, substantially associated with risk of recurrence and death. The up-regulation of ETV5 transcription factor linked to the promotion of epithelial to mesenchymal transition is considered as a basic mechanism underlying the initial steps of EC invasion. In this work, we aimed to investigate the transcription program of tumor invasion regulated by ETV5. We performed a comparative Chip-on-chip analysis at invasive front and superficial area of human EC. ETV5 specific binding to promoter regions of genes related to cellular migration, adhesion and invasion at deep invasion tumor areas highlighted the relevance of neural networks associated with cellular plasticity. Interestingly, brain-derived neurotrophic factor (BDNF) demonstrated a principal role orchestrating ETV5-mediated epithelial-to-mesenchymal transition in endometrial cancer. Impairment of the BDNF/tropomyosin-related kinase B (TrkB)/extracellular signal-regulated kinase axis in endometrial cancer cell lines reversed the aggressive and invasive phenotype promoted by the up-regulation of ETV5 at the invasive front of EC. Likewise, BDNF directly impacted on the efficiency of ETV5 promoted metastasis in a mice model of endometrial distant dissemination. These results translate the recognized role of BDNF/TrkB on neural plasticity into a relevant cancer metastasis event; suggest common mechanisms shared by neural development and tumor invasion; and offer new therapeutic opportunities specifically directed against disseminated disease in endometrial cancer.

ERα-mediated repression of pro-inflammatory cytokine expression by glucocorticoids reveals a crucial role for TNFα and IL1α in lumen formation and maintenance.

Most glandular tissues comprise polarized epithelial cells organized around a single central lumen. Although there is active research investigating the molecular networks involved in the regulation of lumenogenesis, little is known about the extracellular factors that influence lumen formation and maintenance. Using a three-dimensional culture system of epithelial endometrial cells, we have revealed a new role for pro-inflammatory cytokines such as TNFα and IL1α in the formation and, more importantly, maintenance of a single central lumen. We also studied the mechanism by which glucocorticoids repress TNFα and IL1α expression. Interestingly, regulation of pro-inflammatory cytokine expression and subsequent lumen formation is mediated by estrogen receptor α (ERα) but not by the glucocorticoid receptor. Finally, we investigated the signaling pathways involved in the regulation of lumen formation by pro-inflammatory cytokines. Our results demonstrate that activation of the ERK/MAPK signaling pathway, but not the PI3K/Akt signaling pathway, is important for the formation and maintenance of a single central lumen. In summary, our results suggest a novel role for ERα-regulated pro-inflammatory cytokine expression in lumen formation and maintenance.

Long-term estradiol exposure is a direct mitogen for insulin/EGF-primed endometrial cells and drives PTEN loss-induced hyperplasic growth.

Loss of tumor-suppressor PTEN is the most common alteration in endometrial carcinoma. However, the relationship between loss of PTEN, growth factors [eg, insulin/insulin-like growth factor (IGF)-1], epidermal growth factor (EGF), and hyperestrogenism in the development of endometrial carcinoma is still controversial. By using three-dimensional (3D) cultures of PTEN(+/+) and PTEN(+/-) endometrial epithelial cells, we investigated the effects of EGF, insulin/IGF, and estradiol in endometrial cell proliferation. We have previously demonstrated that 3D cultures of endometrial cells require EGF and insulin/IGF to proliferate. Herein, we demonstrate that, in the presence of EGF and insulin/IGF, long-term estradiol treatment directly induces proliferation of 3D cultures. Moreover, we show that the mitogenic effects of estradiol require the presence of insulin/IGF and EGF, because withdrawal of such factors completely abolishes estradiol-induced proliferation. In the presence of EGF and insulin/IGF, PTEN(+/-) and PTEN(+/+) spheroids display a similar rate of proliferation. However, the addition of estradiol causes an exaggerated proliferation of PTEN(+/-) cultures, leading to formation of complex structures, such as those observed in endometrial hyperplasia or carcinoma. In summary, we demonstrate that EGF and insulin/IGF prime endometrial epithelial cells to direct the mitogenic effects of estradiol. Furthermore, PTEN deficiency results in enhanced responsiveness to this combination, leading to the development of hyperplasia of endometrial cells in culture.

Endometrial epithelial cell organoids as tools for studying the CD39 family of enzymes and for validating enzyme inhibitors.

Extracellular adenosine triphosphate (ATP) conducts a complex dynamic system of broadly represented cell signaling. Ectonucleotidases are the enzymes with nucleotide hydrolytic ability that regulate ATP levels in physiological and pathological conditions, thus playing a key role in the so-called purinergic signaling. Altered ectonucleotidase expression has been reported in cancer, and the ectonucleoside triphosphate diphosphohydrolase (NTPDase) family of enzymes, with its best-known form NTPDase1 (CD39), is targeted in cancer immunotherapy. The tandem of enzymes CD39-CD73 is responsible for the generation of immunosuppressive adenosine in the tumor microenvironment, and inhibition strategies are of great interest. Organoids have emerged as very convenient models for the study of tumors since they are three-dimensional cultures that retain many of the features of tissue. The present study aims to contribute to improving the methodology and the molecular tools needed for the study of ectonucleotidases in healthy and disease conditions. The study, performed in an endometrial cancer cell model, could be extended to other types of tumors and pathologies in which the purinergic system is involved. We generated organoids from endometrial cancer cells overexpressing NTPDase2 (CD39L1) and NTPDase3 (CD39L3) as fusion proteins with EGFP, and we performed functional assays by adapting in situ cytochemistry protocols. This allowed us to simultaneously detect enzyme activity and protein expression and to demonstrate that organoids can be used to test ectonucleotidase inhibitors-a result that can be used to develop new cancer treatment options.

Metabolomic-Based Approaches for Endometrial Cancer Diagnosis and Prognosis: A Review.

Endometrial cancer, the most prevalent gynecological malignancy in developed countries, is experiencing a sustained rise in both its incidence and mortality rates, primarily attributed to extended life expectancy and lifestyle factors. Currently, the absence of precise diagnostic tools hampers the effective management of the expanding population of women at risk of developing this disease. Furthermore, patients diagnosed with endometrial cancer require precise risk stratification to align with optimal treatment planning. Metabolomics technology offers a unique insight into the molecular landscape of endometrial cancer, providing a promising approach to address these unmet needs. This comprehensive literature review initiates with an overview of metabolomic technologies and their intrinsic workflow components, aiming to establish a fundamental understanding for the readers. Subsequently, a detailed exploration of the existing body of research is undertaken with the objective of identifying metabolite biomarkers capable of enhancing current strategies for endometrial cancer diagnosis, prognosis, and recurrence monitoring. Metabolomics holds vast potential to revolutionize the management of endometrial cancer by providing accuracy and valuable insights into crucial aspects.

KSR1 is overexpressed in endometrial carcinoma and regulates proliferation and TRAIL-induced apoptosis by modulating FLIP levels.

The Raf/MEK/extracellular signal-regulated kinase (ERK) pathway participates in many processes altered in development and progression of cancer in human beings such as proliferation, transformation, differentiation, and apoptosis. Kinase suppressor of Ras 1 (KSR1) can interact with various kinases of the Raf/MEK/extracellular signal-regulated kinase pathway to enhance its activation. The role of KSR1 in endometrial carcinogenesis was investigated. cDNA and tissue microarrays demonstrated that expression of KSR1 was up-regulated in endometrial carcinoma. Furthermore, inhibition of KSR1 expression by specific small hairpin RNA resulted in reduction of both proliferation and anchorage-independent cell growth properties of endometrial cancer cells. Because inhibition of apoptosis has a pivotal role in endometrial carcinogenesis, the effects of KSR1 in regulation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis were investigated. KSR1 knock-down sensitized resistant endometrial cell lines to both TRAIL- and Fas-induced apoptosis. Sensitization to TRAIL and agonistic anti-Fas antibody was caused by down-regulation of FLIP (FLICE-inhibitory protein). Also investigated was the molecular mechanism by which KSR1 regulates FLIP protein levels. It was demonstrated that KSR1 small hairpin RNA did not affect FLIP transcription or degradation. Rather, FLIP down-regulation was caused by Fas-associated death domain protein-dependent inhibition of FLIP translation triggered after TRAIL stimulation in KSR1-silenced cells. Re-expression of heterologous KSR1 in cells with down-regulated endogenous KSR1 restored FLIP protein levels and TRAIL resistance. In conclusion, KSR1 regulates endometrial sensitivity to TRAIL by regulating FLIP levels.

Metabolomic Analysis Points to Bioactive Lipid Species and Acireductone Dioxygenase 1 (ADI1) as Potential Therapeutic Targets in Poor Prognosis Endometrial Cancer.

Metabolomic profiling analysis has the potential to highlight new molecules and cellular pathways that may serve as potential therapeutic targets for disease treatment. In this study, we used an LC-MS/MS platform to define, for the first time, the specific metabolomic signature of uterine serous carcinoma (SC), a relatively rare and aggressive variant of endometrial cancer (EC) responsible for 40% of all endometrial cancer-related deaths. A metabolomic analysis of 31 ECs (20 endometrial endometrioid carcinomas (EECs) and 11 SCs) was performed. Following multivariate statistical analysis, we identified 232 statistically different metabolites among the SC and EEC patient samples. Notably, most of the metabolites identified (89.2%) were lipid species and showed lower levels in SCs when compared to EECs. In addition to lipids, we also documented metabolites belonging to amino acids and purine nucleotides (such as 2-Oxo-4-methylthiobutanoic acid, synthesised by acireductone dioxygenase 1 (ADI1) enzyme), which showed higher levels in SCs. To further investigate the role of ADI1 in SC, we analysed the expression protein levels of ADI1 in 96 ECs (67 EECs and 29 SCs), proving that the levels of ADI1 were higher in SCs compared to EECs. We also found that ADI1 mRNA levels were higher in p53 abnormal ECs compared to p53 wild type tumours. Furthermore, elevated ADI1 mRNA levels showed a statistically significant negative correlation with overall survival and progression-free survival among EEC patients. Finally, we tested the ability of ADI1 to induce migration and invasion capabilities in EC cell lines. Altogether, these results suggest that ADI1 could be a potential therapeutic target in poor-prognosis SCs and other Ecs with abnormal p53 expression.

Lack of extracellular matrix switches TGF-ß induced apoptosis of endometrial cells to epithelial to mesenchymal transition.

The extracellular matrix and the correct establishment of epithelial cell polarity plays a critical role in epithelial cell homeostasis and cell polarity. In addition, loss of tissue structure is a hallmark of carcinogenesis. In this study, we have addressed the role of extracellular matrix in the cellular responses to TGF-ß. It is well known that TGF-ß is a double-edged sword: it acts as a tumor suppressor in normal epithelial cells, but conversely has tumor-promoting effects in tumoral cells. However, the factors that determine cellular outcome in response to TGF-ß remain controversial. Here, we have demonstrated that the lack of extracellular matrix and consequent loss of cell polarity inhibits TGF-ß-induced apoptosis, observed when endometrial epithelial cells are polarized in presence of extracellular matrix. Rather, in absence of extracellular matrix, TGF-ß-treated endometrial epithelial cells display features of epithelial-to-mesenchymal transition. We have also investigated the molecular mechanism of such a switch in cellular response. On the one hand, we found that the lack of Matrigel results in increased AKT signaling which is sufficient to inhibit TGF-ß-induced apoptosis. On the other hand, we demonstrate that TGF-ß-induced epithelial-to-mesenchymal transition requires ERK and SMAD2/3 activation. In summary, we demonstrate that loss of cell polarity changes the pro-apoptotic function of TGF-ß to tumor-associated phenotype such as epithelial-to-mesenchymal transition. These results may be important for understanding the dual role of TGF-ß in normal versus tumoral cells.

ARID1A-deficient cells require HDAC6 for progression of endometrial carcinoma.

AT-rich interactive domain-containing protein 1A (ARID1A) loss-of-function mutation accompanied by a loss of ARID1A protein expression is frequently observed in endometrial carcinomas. However, the molecular mechanisms linking these genetic changes to the altered pathways regulating tumour initiation, maintenance and/or progression remain poorly understood. Thus, the main aim of this study was to analyse the role of ARID1A loss of function in endometrial tumorigenesis. Here, using different endometrial in vitro and in vivo models, such as tumoral cell lines, 3D primary cultures and metastatic or genetically modified mouse models, we show that altered expression of ARID1A is not enough to initiate endometrial tumorigenesis. However, in an established endometrial cancer context, ARID1A loss of function accelerates tumoral progression and metastasis through the disruption of the G2/M cell cycle checkpoint and ATM/ATR-mediated DNA damage checkpoints, increases epithelial cell proliferation rates and induces epithelial mesenchymal transition through the activation of histone deacetylase 6 (HDAC6). Next, we demonstrated that the inhibition of HDAC6 function, using the HDAC6-specific inhibitor ACY1215 or by transfection with HDAC6 short hairpin RNA (shRNA), can reverse the migratory and invasive phenotype of ARID1A-knockdown cells. Further, we also show that inhibition of HDAC6 activity causes an apoptotic vulnerability to etoposide treatments in ARID1A-deficient cells. In summary, the findings exposed in this work indicate that the inhibition of HDAC6 activity is a potential therapeutic strategy for patients suffering from ARID1A-mutant endometrial cancer diagnosed in advanced stages.

Integrating digital pathology with transcriptomic and epigenomic tools for predicting metastatic uterine tumor aggressiveness.

The incidence of new cancer cases is expected to increase significantly in the future, posing a worldwide problem. In this regard, precision oncology and its diagnostic tools are essential for developing personalized cancer treatments. Digital pathology (DP) is a particularly key strategy to study the interactions of tumor cells and the tumor microenvironment (TME), which play a crucial role in tumor initiation, progression and metastasis. The purpose of this study was to integrate data on the digital patterns of reticulin fiber scaffolding and the immune cell infiltrate, transcriptomic and epigenetic profiles in aggressive uterine adenocarcinoma (uADC), uterine leiomyosarcoma (uLMS) and their respective lung metastases, with the aim of obtaining key TME biomarkers that can help improve metastatic prediction and shed light on potential therapeutic targets. Automatized algorithms were used to analyze reticulin fiber architecture and immune infiltration in colocalized regions of interest (ROIs) of 133 invasive tumor front (ITF), 89 tumor niches and 70 target tissues in a total of six paired samples of uADC and nine of uLMS. Microdissected tissue from the ITF was employed for transcriptomic and epigenetic studies in primary and metastatic tumors. Reticulin fiber scaffolding was characterized by a large and loose reticular fiber network in uADC, while dense bundles were found in uLMS. Notably, more similarities between reticulin fibers were observed in paired uLMS then paired uADCs. Transcriptomic and multiplex immunofluorescence-based immune profiling showed a higher abundance of T and B cells in primary tumor and in metastatic uADC than uLMS. Moreover, the epigenetic signature of paired samples in uADCs showed more differences than paired samples in uLMS. Some epigenetic variation was also found between the ITF of metastatic uADC and uLMS. Altogether, our data suggest a correlation between morphological and molecular changes at the ITF and the degree of aggressiveness. The use of DP tools for characterizing reticulin scaffolding and immune cell infiltration at the ITF in paired samples together with information provided by omics analyses in a large cohort will hopefully help validate novel biomarkers of tumor aggressiveness, develop new drugs and improve patient quality of life in a much more efficient way.

Nuclear factor-κB2/p100 promotes endometrial carcinoma cell survival under hypoxia in a HIF-1α independent manner.

Endometrial carcinoma (EC) is a common female cancer, treated mainly by surgery and adjuvant radiotherapy. Relapse following treatment is associated with increased risk of metastases. Hypoxia, a common microenvironment in solid tumors, correlates with malignant progression, rendering tumors resistant to ionizing therapy. Hence, we assessed here the immunohistochemical expression of hypoxia-inducible factor-1α (HIF-1α) and members of the NF-κB family in 82 primary EC and 10 post-radiation recurrences of EC. Post-radiation recurrences were highly hypoxic, with a higher expression of HIF-1α and also RelA (p65) and p52 when compared with primary EC. We next investigated the effects of hypoxia on EC cell lines. We found that EC cell lines are highly resistant to hypoxia-induced apoptosis. We thus focused on the molecular mechanisms involved in conferring hypoxic cell death resistance. We show that in addition to the classical NF-κB, hypoxia activates the alternative NF-κB pathway. To characterize the upstream kinases involved in the activation of these pathways, we used lentiviral-mediated knockdown and mouse embryonic fibroblasts lacking IKKα and IKKß kinases. Both IKKα and IKKß kinases are required for RelA (p65) and p100 accumulation, whereas p52 processing under hypoxia is IKKα dependent. Furthermore, Ishikawa endometrial cell line harboring either RelA (p65) or p52 short-hairpin RNA was sensitive to hypoxia-induced cell death, indicating that, in addition to the known prosurvival role of RelA (p65) under hypoxia, alternative NF-κB pathway also enhances hypoxic survival of EC cells. Interestingly, although HIF-1α controlled classical NF-κB activation pathway and survival under hypoxia through RelA (p65) nuclear accumulation, the alternative pathway was HIF-1α independent. These findings have important clinical implications for the improvement of EC prognosis before radiotherapy.