Clinical translation for endometrial cancer stem cells hypothesis

Influence of Aldehyde Dehydrogenase Inhibition on Stemness of Endometrial Cancer Stem Cells

Endometrial cancer is one of the most common gynaecological malignancies. Although often diagnosed at an early stage, there is a subset of patients with recurrent and metastatic disease for whom current treatments are not effective. Cancer stem cells (CSCs) play a pivotal role in triggering tumorigenesis, disease progression, recurrence, and metastasis, as high aldehyde dehydrogenase (ALDH) activity is associated with invasiveness and chemotherapy resistance. Therefore, this study aimed to evaluate the effects of ALDH inhibition in endometrial CSCs. ECC-1 and RL95-2 cells were submitted to a sphere-forming protocol to obtain endometrial CSCs. ALDH inhibition was evaluated through ALDH activity and expression, sphere-forming capacity, self-renewal, projection area, and CD133, CD44, CD24, and P53 expression. A mass spectrometry-based proteomic study was performed to determine the proteomic profile of endometrial cancer cells upon N,N-diethylaminobenzaldehyde (DEAB). DEAB reduced ALDH activity and expression, along with a significant decrease in sphere-forming capacity and projection area, with increased CD133 expression. Additionally, DEAB modulated P53 expression. Endometrial cancer cells display a distinct proteomic profile upon DEAB, sharing 75 up-regulated and 30 down-regulated proteins. In conclusion, DEAB inhibits ALDH activity and expression, influencing endometrial CSC phenotype. Furthermore, ALDH18A1, SdhA, and UBAP2L should be explored as novel molecular targets for endometrial cancer.

Identification ATP5F1D as a Biomarker Linked to Diagnosis, Prognosis, and Immune Infiltration in Endometrial Cancer Based on Data-Independent Acquisition (DIA) Analysis

In developed countries, endometrial cancer (EC) is the most prevalent gynecological cancer. ATP5F1D is a subunit of ATP synthase, as well as an important component of the mitochondrial electron transport chain (ETC). ETC plays a compelling role in carcinogenesis. To date, little is known about the role of ATP5F1D in EC. We undertook data-independent acquisition mass spectrometry (DIA-MS) of 20 EC patients, comprising 10 high-grade and 10 low-grade cancer tissues. Biological functions of differentially expressed genes (DEGs) were analyzed by GO and KEGG. The expression level, clinicopathological features, diagnostic potency, prognostic value, RNA modifications, immune characteristics, and therapy response of ATP5F1D were investigated. In total, 77 DEGs were acquired by DIA analysis, which were closely related to regulating immune response and metabolic pathways. Among the five genes (NDUFB8, SLC26A2, RAF1, ATP5F1D, and GSTM5) involving in reactive oxygen species pathway, ATP5F1D showed the most significant differential expression (2.903-fold change). We found ATP5F1D had a high diagnostic value and was associated with a favorable prognosis in EC patients. After analyzing the RNA modifications of ATP5F1D, revealing a negative regulation between them. Additionally, ATP5F1D was closely related to tumor immune infiltration. Our results suggested T-cell dysfunction and TAM-M2 polarization might be the important mechanisms of ATP5F1D to facilitate tumor immune escape. Noticeably, EC patients with ATP5F1D-high expression had better immune treatment responses and were more sensitive to chemotherapy drugs. ATP5F1D can be used as a biomarker for diagnosis, prognosis, and immune infiltration of EC, and offers a crucial reference for personalized treatment of EC patients.

Exosomes in Cancer: Diagnostic and Therapeutic Applications

Small extracellular vesicles called exosomes are produced by cells and contain a range of biomolecules, including proteins, lipids, and nucleic acids. Exosomes have been implicated in the development and spread of cancer, and recent studies have shown that their contents may be exploited as biomarkers for early detection and ongoing surveillance of the disease. In this review article, we summarize the current knowledge on exosomes as biomarkers of cancer. We discuss the various methods used for exosome isolation and characterization, as well as the different types of biomolecules found within exosomes that are relevant for cancer diagnosis and prognosis. We also highlight recent studies that have demonstrated the utility of exosomal biomarkers in different types of cancer, such as lung cancer, breast cancer, and pancreatic cancer. Overall, exosomes show great promise as noninvasive biomarkers for cancer detection and monitoring. Exosomes have the ability to transform cancer diagnostic and therapeutic paradigms, providing promise for more efficient and individualized. This review seeks to serve as an inspiration for new ideas and research in the never-ending fight against cancer. Moreover, further studies are needed to validate their clinical utility and establish standardized protocols for their isolation and analysis. With continued research and development, exosomal biomarkers have the potential to revolutionize cancer diagnosis and treatment.

PVT1/miR-136/Sox2/UPF1 axis regulates the malignant phenotypes of endometrial cancer stem cells

Tumor stem cells (TSCs) are thought to contribute to the progression and maintenance of cancer. Previous studies have suggested that plasmacytoma variant translocation 1 (PVT1) has a tumor-promoting effect on endometrial cancer; however, its mechanism of action in endometrial cancer stem cells (ECSCs) is unknown. Here, we found that PVT1 was highly expressed in endometrial cancers and ECSCs, correlated with poor patient prognosis, promoted the malignant behavior and the stemness of endometrial cancer cells (ECCs) and ECSCs. In contrast, miR-136, which was lowly expressed in endometrial cancer and ECSCs, had the opposite effect, and knockdown miR-136 inhibited the anticancer effects of down-regulated PVT1. PVT1 affected miR-136 specifically binding the 3' UTR region of Sox2 by competitively "sponging" miR-136, thus positively saving Sox2. Sox2 promoted the malignant behavior and the stemness of ECCs and ECSCs, and overexpression Sox2 inhibited the anticancer effects of up-regulated miR-136. Sox2 can act as a transcription factor to positively regulate Up-frameshift protein 1 (UPF1) expression, thereby exerting a tumor-promoting effect on endometrial cancer. In nude mice, simultaneously downregulating PVT1 and upregulating miR-136 exerted the strongest antitumor effect. We demonstrate that the PVT1/miR-136/Sox2/UPF1 axis plays an important role in the progression and maintenance of endometrial cancer. The results suggest a novel target for endometrial cancer therapies.

Aldehyde dehydrogenase in solid tumors and other diseases: Potential biomarkers and therapeutic targets

The family of aldehyde dehydrogenases (ALDHs) contains 19 isozymes and is involved in the oxidation of endogenous and exogenous aldehydes to carboxylic acids, which contributes to cellular and tissue homeostasis. ALDHs play essential parts in detoxification, biosynthesis, and antioxidants, which are of important value for cell proliferation, differentiation, and survival in normal body tissues. However, ALDHs are frequently dysregulated and associated with various diseases like Alzheimer's disease, Parkinson's disease, and especially solid tumors. Notably, the involvement of the ALDHs in tumor progression is responsible for the maintenance of the stem-cell-like phenotype, triggering rapid and aggressive clinical progressions. ALDHs have captured increasing attention as biomarkers for disease diagnosis and prognosis. Nevertheless, these require further longitudinal clinical studies in large populations for broad application. This review summarizes our current knowledge regarding ALDHs as potential biomarkers in tumors and several non-tumor diseases, as well as recent advances in our understanding of the functions and underlying molecular mechanisms of ALDHs in disease development. Finally, we discuss the therapeutic potential of ALDHs in diseases, especially in tumor therapy with an emphasis on their clinical implications.

Molecular mechanism(s) of regulations of cancer stem cell in brain cancer propagation

Brain tumors are most often diagnosed with solid neoplasms and are the primary reason for cancer-related deaths in both children and adults worldwide. With recent developments in the progression of novel targeted chemotherapies, the prognosis of malignant glioma remains dismal. However, the high recurrence rate and high mortality rate remain unresolved and are closely linked to the biological features of cancer stem cells (CSCs). Research on tumor biology has reached a new age with more understanding of CSC features. CSCs, a subpopulation of whole tumor cells, are now regarded as candidate therapeutic targets. Therefore, in the diagnosis and treatment of tumors, recognizing the biological properties of CSCs is of considerable significance. Here, we have discussed the concept of CSCs and their significant role in brain cancer growth and propagation. We have also discussed personalized therapeutic development and immunotherapies for brain cancer by specifically targeting CSCs.

Applications of Photodynamic Therapy in Endometrial Diseases

Photodynamic therapy (PDT) is a medical procedure useful for several benign conditions (such as wound healing and infections) and cancer. PDT is minimally invasive, presents few side effects, good scaring, and is able to minimal tissue destruction maintaining organ anatomy and function. Endoscopic access to the uterus puts PDT in the spotlight for endometrial disease treatment. This work systematically reviews the current evidence of PDT’s potential and usefulness in endometrial diseases. Thus, this narrative review focused on PDT applications for endometrial disease, including reports regarding in vitro, ex vivo, animal, and clinical studies. Cell lines and primary samples were used as in vitro models of cancer, adenomyosis and endometrioses, while most animal studies focused the PDT outcomes on endometrial ablation. A few clinical attempts are known using PDT for endometrial ablation and cancer lesions. This review emphasises PDT as a promising field of research. This therapeutic approach has the potential to become an effective conservative treatment method for endometrial benign and malignant lesions. Further investigations with improved photosensitisers are highly expected.

Emerging role of circulating tumor cells in immunotherapy

Over the last few years, immunotherapy, in particular, immune checkpoint inhibitor therapy, has revolutionized the treatment of several types of cancer. At the same time, the uptake in clinical oncology has been slow owing to the high cost of treatment, associated toxicity profiles and variability of the response to treatment between patients. In response, personalized approaches based on predictive biomarkers have emerged as new tools for patient stratification to achieve effective immunotherapy. Recently, the enumeration and molecular analysis of circulating tumor cells (CTCs) have been highlighted as prognostic biomarkers for the management of cancer patients during chemotherapy and for targeted therapy in a personalized manner. The expression of immune checkpoints on CTCs has been reported in a number of solid tumor types and has provided new insight into cancer immunotherapy management. In this review, we discuss recent advances in the identification of immune checkpoints using CTCs and shed light on the potential applications of CTCs towards the identification of predictive biomarkers for immunotherapy.

Current understanding of epigenetics mechanism as a novel target in reducing cancer stem cells resistance

At present, after extensive studies in the field of cancer, cancer stem cells (CSCs) have been proposed as a major factor in tumor initiation, progression, metastasis, and recurrence. CSCs are a subpopulation of bulk tumors, with stem cell-like properties and tumorigenic capabilities, having the abilities of self-renewal and differentiation, thereby being able to generate heterogeneous lineages of cancer cells and lead to resistance toward anti-tumor treatments. Highly resistant to conventional chemo- and radiotherapy, CSCs have heterogeneity and can migrate to different organs and metastasize. Recent studies have demonstrated that the population of CSCs and the progression of cancer are increased by the deregulation of different epigenetic pathways having effects on gene expression patterns and key pathways connected with cell proliferation and survival. Further, epigenetic modifications (DNA methylation, histone modifications, and RNA methylations) have been revealed to be key drivers in the formation and maintenance of CSCs. Hence, identifying CSCs and targeting epigenetic pathways therein can offer new insights into the treatment of cancer. In the present review, recent studies are addressed in terms of the characteristics of CSCs, the resistance thereof, and the factors influencing the development thereof, with an emphasis on different types of epigenetic changes in genes and main signaling pathways involved therein. Finally, targeted therapy for CSCs by epigenetic drugs is referred to, which is a new approach in overcoming resistance and recurrence of cancer.

A Risk Signature with Nine Stemness Index-Associated Genes for Predicting Survival of Patients with Uterine Corpus Endometrial Carcinoma

Purpose

To identify mRNA expression-based stemness index- (mRNAsi-) related genes and build an mRNAsi-related risk signature for endometrial cancer.

Methods

We collected mRNAsi data of endometrial cancer samples from The Cancer Genome Atlas (TCGA) and analyzed their relationship with the main clinicopathological characteristics and prognosis of endometrial cancer patients. We screened the top 50% of the genes in TCGA for weighted gene correlation network analysis (WGCNA) to explore mRNAsi-related gene sets. Among these mRNAsi-related genes, we further screened for those related to the prognosis of endometrial cancer patients via univariate Cox regression analysis and least absolute shrinkage and selection operator (LASSO) regression analysis. Using stepwise multivariate Cox regression analysis, a stemness index-related risk signature was constructed. Finally, we identified potential prognostic biomarkers for endometrial cancer by combining the GEO database and immunohistochemical staining.

Results

The mRNAsi of endometrial cancer samples was significantly higher than that of normal samples and was related to the International Federation of Gynecology and Obstetrics (FIGO) stage, pathological grade, postoperative tumor status, and overall survival of endometrial cancer patients. We identified 21 mRNAsi-related gene modules, and 1,324 genes were obtained from the most relevant module. TCGA samples were divided into training and validation cohorts, and the training cohort was used to construct a nine-mRNAsi-related gene signature (B3GAT2, CD3EAP, DMC1, FRMPD3, LINC01224, LINC02068, LY6H, NR6A1, and TLE2). High-risk and low-risk patients had significant prognostic differences, and the risk signature could accurately predict their 1-, 3-, and 5-year survival. The nomogram composed of risk score and multiple clinicopathological features could accurately predict 1-, 3-, and 5-year survival. Finally, CD3EAP was found to be a novel prognostic biomarker for endometrial cancer.

Conclusion

Endometrial cancer cell stemness is related to patient prognosis. The nine-gene risk signature is an independent prognostic factor and can accurately predict endometrial cancer patient prognosis.

Exosomes as Biomarkers for Female Reproductive Diseases Diagnosis and Therapy

Cell-cell communication is an essential mechanism for the maintenance and development of various organs, including the female reproductive system. Today, it is well-known that the function of the female reproductive system and successful pregnancy are related to appropriate follicular growth, oogenesis, implantation, embryo development, and proper fertilization, dependent on the main regulators of cellular crosstalk, exosomes. During exosome synthesis, selective packaging of different factors into these vesicles happens within the originating cells. Therefore, exosomes contain both genetic and proteomic data that could be applied as biomarkers or therapeutic targets in pregnancy-associated disorders or placental functions. In this context, the present review aims to compile information about the potential exosomes with key molecular cargos that are dysregulated in female reproductive diseases which lead to infertility, including polycystic ovary syndrome (PCOS), premature ovarian failure (POF), Asherman syndrome, endometriosis, endometrial cancer, cervical cancer, ovarian cancer, and preeclampsia, as well as signaling pathways related to the regulation of the reproductive system and pregnancy outcome during these pathological conditions. This review might help us realize the etiology of reproductive dysfunction and improve the early diagnosis and treatment of the related complications.

Notch and Endometrial Cancer

The human endometrium is a unique, highly dynamic tissue that undergoes cyclic changes of cell proliferation, differentiation, and death. Endometrial cancer is the most common malignancy among women in developed countries. Importantly, the incidence of endometrial cancer is rising in high-income countries. Currently histological classification is used for subtyping of endometrial cancer, while ongoing research is evaluating markers for more accurate molecular classification. Evolutionary conserved Notch signaling pathway regulates diverse cellular processes such as proliferation, differentiation, and cell invasion. Accumulating evidence links aberrant Notch signaling with diseases such as hyperplasia and endometrial cancer. This chapter summarizes the current state of Notch signaling investigations in the endometrium, endometriosis, and endometrial cancer.

Endometrial Cancer Stem Cells: Role, Characterization and Therapeutic Implications

Endometrial cancer (EC) is the most frequent gynecological cancer. In patients with relapsed and advanced disease, prognosis is still dismal and development of resistance is common. In this context, endometrial Cancer Stem Cells (eCSC), stem-like cells capable to self-renewal and differentiation in mature cancer cells, represent a potential field of expansion for drug development. The aim of this review is to characterize the role of eCSC in EC, their features and how they could be targeted. CSC are involved in progression, invasiveness and metastasis (though epithelial to mesenchimal transition, EMT), as well as chemoresistance in EC. Nevertheless, isolation of eCSC is still controversial. Indeed, CD133, Aldheyde dehydrogenase (ALDH), CD117, CD55 and CD44 are enriched in CSCs but there is no universal marker nowadays. The most frequently activated pathways in eCSC are Wingless-INT (Wnt)/β-catenin, Notch1, and Hedghog, with a high expression of self-renewal transcription factors like Octamer binding transcription factor 4 (OCT), B Lymphoma Mo-MLV Insertion Region 1 Homolog (BMI1), North American Network Operations Group Homebox protein (NANOG), and SRY-Box 2 (SOX2). These pathways have been targeted with selective drugs alone or in combination with chemotherapy and immunotherapy. Unfortunately, although preclinical results are encouraging, few clinical data are available.

Proteomic Characterization of Epithelial-Like Extracellular Vesicles in Advanced Endometrial Cancer

Endometrial cancer (EC) is the most frequent gynecological cancer. Tumor dissemination affecting ∼20% of EC patients is characterized at the primary carcinoma by epithelial-to-mesenchymal transition (EMT) associated with myometrial infiltration. At distant sites, the interaction of circulating tumor cells (CTCs) with the microenvironment is crucial for metastatic colonization, with a participation of the extracellular vesicles (EVs). We comprehensively approached these primary and secondary sites to study the impact of tumor EVs on the metastatic efficiency of CTCs in EC. Tumor EVs in circulation reproduce the epithelial phenotype predominant in the primary carcinoma, whereas CTCs are characterized by an EMT phenotype. We modeled this EMT-related clinical scenario in the Hec1A endometrial cell line and characterized the epithelial-like EVs in circulation by SILAC proteome analysis. The identification of proteins involved in cell-cell and cell-matrix interaction and binding, together with in vitro evidence of an improved adhesion of CTC to a functionalized endothelium, suggests a contribution of the epithelial-like EVs in the homing of CTCs at metastatic sites. Accordingly, adhesion protein LGALS3BP was found to be significantly enriched in circulating EVs from a cohort of EC patients with a high risk of recurrence by targeted proteomics (multiple reaction monitoring), highlighting its potential in liquid biopsy in EC.

Endometrial Cancer Spheres Show Cancer Stem Cells Phenotype and Preference for Oxidative Metabolism

This study aimed to characterize endometrial cancer regarding cancer stem cells (CSC) markers, regulatory and differentiation pathways, tumorigenicity and glucose metabolism. Endometrial cancer cell line ECC1 was submitted to sphere forming protocols. The first spheres generation (ES1) was cultured in adherent conditions (G1). This procedure was repeated and was obtained generations of spheres (ES1, ES2 and ES3) and spheres-derived cells in adherent conditions (G1, G2 and G3). Populations were characterized regarding CD133, CD24, CD44, aldehyde dehydrogenase (ALDH), hormonal receptors, HER2, P53 and β-catenin, fluorine-18 fluorodeoxyglucose ([¹⁸F]FDG) uptake and metabolism by NMR spectroscopy. An heterotopic model evaluated differential tumor growth. The spheres self-renewal was higher in ES3. The putative CSC markers CD133, CD44 and ALDH expression were higher in spheres. The expression of estrogen receptor (ER)α and P53 decreased in spheres, ERβ and progesterone receptor had no significant changes and β-catenin showed a tendency to increase. There was a higher ¹⁸F-FDG uptake in spheres, which also showed a lower lactate production and an oxidative cytosol status. The tumorigenesis in vivo showed an earlier growth of tumours derived from ES3. Endometrial spheres presented self-renewal and differentiation capacity, expressed CSC markers and an undifferentiated phenotype, showing preference for oxidative metabolism.

Characterizing sarcoma dominance pattern in uterine carcinosarcoma: Homologous versus heterologous element

OBJECTIVE

To examine significance of sarcoma dominance (SD) patterns in uterine carcinosarcoma (UCS).

METHODS

This is a secondary analysis of multicenter retrospective study examining women with stages I-IV UCS who underwent primary surgery. SD was defined as >50% of sarcoma component in uterine tumor. SD patterns were grouped as homologous sarcoma without SD (homo/non-dominance, n = 351), heterologous sarcoma without SD (hetero/non-dominance, n = 174), homologous sarcoma with SD (homo/dominance, n = 175), and heterologous sarcoma with SD (hetero/dominance, n = 189), and correlated to tumor characteristics and survival.

RESULTS

SD patterns were significantly associated with age, body habitus, carcinoma type, tumor size, depth of myometrial invasion, and nodal metastasis (all, P < 0.05). On univariate analysis, SD was associated with decreased progression-free survival (PFS) and cause-specific survival (CSS) in homologous cases (both, P < 0.05) but not in heterologous cases. On multivariate models, both homologous and heterologous SD patterns remained independent prognostic factors for decreased PFS (adjusted-hazard ratio [HR] ranges: homo/dominance 1.35-1.69, and hetero/dominance 1.47-1.64) and CSS (adjusted-HR ranges: 1.52-1.84 and 1.66-1.81, respectively) compared to homo/non-dominance (all, P < 0.05). Among stage I-III disease, when tumors had SD, adding radiotherapy to chemotherapy was significantly associated with improved PFS (adjusted-HR: homo/dominance 0.49, and hetero/dominance 0.45) and CSS (0.36 and 0.31, respectively) compared to chemotherapy alone (all, P < 0.05); contrary, this association was not observed with absence of SD (all, P > 0.05).

CONCLUSION

In UCS, SD impacts survival in homologous but not in heterologous type. Regardless of sarcoma types, SD was associated with decreased survival in UCS; adding radiotherapy to chemotherapy may be an effective postoperative strategy.

Liquid Biopsy in Endometrial Cancer: New Opportunities for Personalized Oncology

The identification of new molecular targets and biomarkers associated with high risk of recurrence and response to therapy represents one of the main clinical challenges in the management of advanced disease in endometrial cancer. In this sense, the field of liquid biopsy has emerged as a great revolution in oncology and is considered "the way" to reach personalised medicine. In this review, we discuss the promising but already relatively limited advances of liquid biopsy in endometrial cancer compared to other types of tumours like breast, colorectal or prostate cancer. We present recent data analysing circulating tumour material in minimally-invasive blood samples, but also in alternative forms of liquid biopsy like uterine aspirates. Proteomic and genomic studies focused on liquid-based uterine samples are resulting not only in optimal diagnostic tools but also in reliable approaches to address tumour heterogeneity. Likewise, circulating tumour cells (CTCs) and circulating tumour DNA (ctDNA) represent an opportunity for the correct stratification of patients, for the assessment of early recurrent disease or for the real-time monitoring of therapy responses. Appropriately designed studies and implementation in clinical trials will determine the value of liquid biopsy for precision oncology in endometrial cancer.

Evaluation of Vav3.1 as prognostic marker in endometrial cancer

PURPOSE

Vav3 is a guanine nucleotide exchange factor that regulates the activity of Rho/Rac family GTPases. In a study on ovarian cancer, we recently demonstrated pronounced prognostic and predictive value of Vav3.1, a specific truncation variant of the parental Vav3 gene. Here, we sought to investigate the role of Vav3.1 in the most prevalent gynecological tumor entity, endometrial cancer.

METHODS

Vav3.1 transcript levels were determined in a large cohort of endometrial cancer patients using variant-specific PCR (n = 239), and non-malignant endometrial tissue served as control (n = 26). Expression levels of Vav3.1 were stratified according to established clinicopathological characteristics and correlated to long-term patient survival (average follow-up of > 7.5 years). Type 1 and type 2 cancers were separately investigated.

RESULTS

While Vav3.1 was markedly overexpressed in endometrial cancer tissue, we could not detect associations with clinical parameters related to prognosis, such as FIGO stage and tumor grade. Kaplan-Meier estimators of different measures of survival failed to show prognostic significance of Vav3.1 in endometrial cancer. Lack of prognostic value was observed for both type 1 and type 2 cancers.

CONCLUSIONS

Our study shows that Vav3.1 is not suited as a marker of cancer progression and/or treatment response in endometrial cancer. Feasibility and potential benefit of targeting Vav3.1 in endometrial cancer needs to be evaluated in future studies, proceeding from its clear, roughly ten-fold, induction in the malignant endometrium.

The Use of Endometrial Cancer Patient-Derived Organoid Culture for Drug Sensitivity Testing Is Feasible

Supplemental digital content is available in the text.

Objective

Patient-derived organoids (PDOs), used in multiple tumor types, have allowed evaluation of tumor characteristics from individual patients. This study aimed to assess the feasibility of applying PDO in vitro culture for endocrine-based and drug sensitivity testing in endometrial cancer.

Methods

Endometrial cancer cells were enzymatically dissociated from tumors retrieved from fresh hysterectomy specimens and cultured within basement membrane extract in serum-free medium. An organoid growth assay was developed to assess the inhibitory effects of a variety of drugs including endocrine treatments. Organoid cultures were also prepared for histological and immunohistochemical comparison to the tumors of origin.

Results

Fifteen endometrial cancer specimens were successfully cultured as PDOs. Small spherical structures formed within 24 hours, and many continued to grow to larger, denser organoids, providing the basis for an organoid growth assay. The STAT3 transcription factor inhibitor, BBI608 (Napabucasin), strongly inhibited growth in almost all PDO cultures, suggesting that stemness programing is involved in organoid formation and/or growth. Inhibition by different growth factor receptor tyrosine kinase inhibitors was observed in several PDO specimens. Four cultures were inhibited by fulvestrant, implying the importance of estrogen-receptor signaling in some PDO cultures. Organoids closely resembled their tumors of origin in both histomorphology and immunohistochemical expression.

Conclusions

The use of endometrial cancer PDO cultures for development of drug sensitivity testing for individual patient tumors is feasible. The potential value of the PDO model for clinical decision making will require clinical trial evaluation.

MicroRNA-34a inhibits cells proliferation and invasion by downregulating Notch1 in endometrial cancer

MicroRNAs (miRNAs) are small non-coding RNAs composed of 18-25 nucleotides that regulate the expression of approximately 30% of human protein coding genes. Dysregulation of miRNAs plays a pivotal role in the initiation and progression of malignancies. Our study has shown that microRNA-34a (miR-34a) was upregulated in human endometrial cancer stem cells (ECSCs). However, it is unknown how miR-34a regulates endometrial cancer itself. Here, we report that miR-34a directly and functionally targeted Notch1. MiR-34a inhibited the proliferation, migration, invasion, EMT-associated phenotypes by downregulating Notch1 in endometrial cancer cells. Overexpression of miR-34a also suppressed tumor growth in nude mice. Importantly, further results suggested miR-34a was significantly downregulated in endometrial cancer tissues and negatively correlated with Notch1 expression. There was a significant association between decreased miR-34a expression and worse patient prognosis. Taken together, our results suggest that miR-34a plays tumor-suppressive roles in endometrial cancer through downregulating Notch1. Thus miR-34a could be a potential therapeutic target for prevention and treatment of endometrial cancer.

Primary patient-derived lung adenocarcinoma cell culture challenges the association of cancer stem cells with epithelial-to-mesenchymal transition

The cancer stem cell (CSC) and epithelial-to-mesenchymal transition (EMT) models have been closely associated and used to describe both the formation of metastasis and therapy resistance. We established a primary lung cell culture from a patient in a clinically rare and unique situation of primary resistant disease. This culture consisted of two biologically profoundly distinct adenocarcinoma cell subpopulations, which differed phenotypically and genotypically. One subpopulation initiated and sustained in spheroid cell culture (LT22s) whereas the other subpopulation was only capable of growth and proliferation under adherent conditions (LT22a). In contrast to our expectations, LT22s were strongly associated with the epithelial phenotype, and expressed additionally CSC markers ALDH1 and CD133, whereas the LT22a was characterized as mesenchymal with lack of CSC markers. The LT22s cells also demonstrated an invasive behavior and mimicked gland formation. Finally, LT22s were more resistant to Cisplatin than LT22a cells. We demonstrate a primary lung adenocarcinoma cell culture derived from a patient with resistant disease, with epithelial aggressive subpopulation of cells associated with stem cell features and therapy resistance. Our findings challenge the current model associating CSC and disease resistance mainly to mesenchymal cells and may have important clinical implications.

Autophagy plays an important role in stemness mediation and the novel dual function of EIG121 in both autophagy and stemness regulation of endometrial carcinoma JEC cells

Endometrial cancer (EC) is the third most common gynecologic malignancy in the world, and is considered a chemotherapy poor responding cancer. There are two underlying mechanisms on chemoresistance: the stemness of cancer stem cells (CSCs) and activation of pro-survival autophagy. It was found that autophagy is one of the main factors of cancer stem cell survival, multidrug resistance and maintenance of the homeostasis of cancer stem cells and normal cancer cells. However, the relationship between CSCs and autophagy of EC cells is still unknown. In this study, higher autophagy level was found in endometrial cancer stem cells (ECSCs) and stemness kept in line with autophagy in successive cultured JEC spheres. Autophagy inhibition decreased the properties of CSCs in JEC spheres and enhanced sensitivity of ECSCs to paclitaxel. Besides, it was found that EIG121 exerted dual functions in the regulation of autophagy and stemness not only in normal JEC cells but also JEC obtained CSCs. These findings could be useful for developing targeted therapies for endometrial carcinoma.

Preliminary identification of endometrial cancer stem cells in vitro and in vivo

Stem cells play a critical role in endometrial cancer progression. However, the current methodologies used to isolate endometrial cancer stem cells (ECSCs) remain unsatisfactory. The ECSCs were isolated by serumfree suspension cultivation. The stem cells-related genes CD44, CD133, Oct4, Sox2 and Nanog were analyzed, and the biological behaviour of ECSCs was evaluated in vitro and vivo. The results suggest that (i) serumfree suspension cultivation is non-toxic and a convenient way for isolating the ECSCs, and is not limited to specific surface markers; (ii) Ishikawa cells can be used as an effective source of ECSCs, and the obtained ECSCs expressing the pluripotent stem cells markers CD44, CD133, Oct4, Sox2, and Nanog; (iii) ECSCs originated from Ishikawa cells showed an increased ability to invasion and metastasis in vitro, and exhibited a high proliferative capacity and pluripotency in vivo and vitro. These findings indicate that serumfree suspension cultivation is an effective method for isolating ECSCs from Ishikawa cells, and the obtained ECSCs are tumorigenic and display stem cell-like properties.

Insulinemia, heterogeneity of obesity and the risk of different types of endometrial cancer: existing evidence

Due to a number of reasons, endometrial cancer is a point of interest not only for oncologists, but also for a variety of specialists - especially endocrinologists. The endocrinology of endometrial cancer can be firmly divided into two categories - steroid and non-steroid. The steroid approach dominated during several decades due to hyperestrogenization signs observed in some patients. The balance was only regained in the last 15 years, when the role of diabetes and insulin resistance began to draw attention. This review aims to provide an update on connections between insulinemia (insulin resistance) and different obesity phenotypes as well to discuss their relation to development of endometrial cancer, its clinical-morphological features and the increasing number of its molecular-biological subtypes.