Cell Lines KLE Research Articles

Downregulation of ATP5F1D inhibits mtROS/NLRP3/caspase-1/GSDMD axis to suppress pyroptosis-mediated malignant progression of endometrial cancer

PurposeIn developed countries, endometrial cancer (EC) is the most prevalent gynecological cancer and its occurrence is associated with chronic inflammation. ATP5F1D is a subunit of ATP synthase (complex V), as well as the important component of mitochondrial electron transport chain (ETC). ETC play compelling roles in carcinogenesis. To date, little is known about the role of ATP5F1D in EC. MethodsATP5F1D expression was identified in EC tissues and EC cell lines. We evaluated the influence of ATP5F1D on clinical features and prognosis based on TCGA database. The effects of ATP5F1D in EC malignant progression by applying loss-of-function assays in KLE and Ishikawa cell lines were detected by EdU, CCK-8, wound healing, Transwell, and flow cytometry assays. Additionally, electron microscope, LDH release, ELISA, mitochondrial ROS measurement, and Immunofluorescence were performed to demonstrate ATP5F1D can affect the pyroptosis of EC. To observe the anti-tumor effect on ATP5F1D silencing, we established an in vivo human endometrial tumor model using nude mice. ResultsATP5F1D expression was significantly upregulated in EC and was associated with favorable prognosis. ATP5F1D knockdown inhibited the proliferation, invasion, and migration of EC cells. Similarly, in nude mice, ATP5F1D knockdown suppressed the growth EC cells. Knocking down ATP5F1D lead to decrease the production of mitochondrial ROS (mtROS) and inhibited pyroptosis of EC cells. ConclusionDownregulation of ATP5F1D as a new therapeutic strategy that could mediate pyroptosis via suppressing mtROS/NLRP3/caspase-1/GSDMD pathway to inhibit EC progression.

A Multi-Omics Approach Revealed Common Dysregulated Pathways in Type One and Type Two Endometrial Cancers.

Endometrial cancer (EC) is the most frequent gynecologic cancer in postmenopausal women. Pathogenetic mechanisms that are related to the onset and progression of the disease are largely still unknown. A multi-omics strategy can help identify altered pathways that could be targeted for improving therapeutical approaches. In this study we used a multi-omics approach on four EC cell lines for the identification of common dysregulated pathways in type 1 and 2 ECs. We analyzed proteomics and metabolomics of AN3CA, HEC1A, KLE and ISHIKAWA cell lines by mass spectrometry. The bioinformatic analysis identified 22 common pathways that are in common with both types of EC. In addition, we identified five proteins and 13 metabolites common to both types of EC. Western blotting analysis on 10 patients with type 1 and type 2 EC and 10 endometria samples confirmed the altered abundance of NPEPPS. Our multi-omics analysis identified dysregulated proteins and metabolites involved in EC tumor growth. Further studies are needed to understand the role of these molecules in EC. Our data can shed light on common pathways to better understand the mechanisms involved in the development and growth of EC, especially for the development of new therapies.

Cytotoxic effect of 13α-estrane derivatives on breast, endometrial and ovarian cancer cell lines

Hormone-dependent cancers such as breast, uterine, and ovarian cancers account for more than 35% of all cancers in women. Worldwide, these cancers occur in more than 2.7 million women/year and account for 22% of cancer-related deaths/year. The generally accepted mechanism for the pathophysiology of estrogen-dependent cancers is estrogen receptor-mediated cell proliferation associated with an increased number of mutations. Therefore, drugs that can interfere with either local estrogen formation or estrogen action via estrogen receptors are needed. Estrane derivatives that have low or minimal estrogenic activity can affect both pathways. In this study, we investigated the effect of 36 different estrane derivatives on the proliferation of eight breast, endometrial, and ovarian cancer cell lines and the corresponding three control cell lines. Estrane derivatives 3 and 4_2Cl showed a stronger effect on the endometrial cancer cell lines KLE and Ishikawa, respectively, compared with the control cell line HIEEC, with IC50 values of 32.6 microM and 17.9 microM, respectively. Estrane derivative 4_2Cl was most active in the ovarian cancer cell line COV362 compared to the control cell line HIO80 with an IC50 value of 3.6 microM. In addition, estrane derivative 2_4I showed a strong antiproliferative effect on endometrial and ovarian cancer cell lines, while the effect on the control cell line was slight or absent. The addition of halogen at carbon 2 and/or 4 in estrane derivatives 1 and 2 increased the selectivity for endometrial cancer cells. Overall, these results suggest that single estrane derivatives are efficient cytotoxic agents for endometrial and ovarian cancer cell lines, and thus potential lead compounds for drug development.

M6A‐related long noncoding RNAs predict prognosis and indicate therapeutic response in endometrial carcinoma

N6-methyladenosine (m6A) has been identified as the most common, abundant, and conserved internal transcriptional modification. Long noncoding RNAs (lncRNAs) are noncoding RNAs consisting of more than 200 nucleotides, and the expression of various lncRNAs may affect cancer prognosis. The impact of m6A-associated lncRNAs on uterine corpus endometrial carcinoma (UCEC) prognosis is unknown. In this study, UCEC prognosis-related m6A lncRNAs were screened, bioinformatics analysis was performed, and experimental validation was conducted. Endometrial carcinoma (EC) and normal tissue samples were obtained from The Cancer Genome Atlas. The prognosis-related m6A lncRNAs screened by the least absolute shrinkage and selection operator method were used for multivariate Cox proportional risk regression modeling. Principal component analysis and Gene Ontology, immune function difference, and drug sensitivity analyses of the prognostic models were performed. Prognostic analysis was conducted for m6A-associated lncRNAs. The immune infiltration relationship of m6A-associated lncRNAs in EC was identified using the ssGSEA immune infiltration algorithm. A competing endogenouse RNA network was constructed using the LncACTdb database. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) assays were used to validate the differences in m6A-related lncRNA expression in normal and EC cells. CDKN2B-AS1 and MIR924HG were found to be risk factors for EC. RAB11B-AS1 was a protective factor in EC patients. MIR924HG expression was upregulated in KLE and RL95-2 endometrial cancer cell lines. Prognostic models involved RAB11B-AS1, LINC01812, HM13-IT1, TPM1-AS, SLC16A1-AS1, LINC01936, and CDKN2B-AS1. The high-risk group was more sensitive to five compounds (ABT.263, ABT.888, AP.24534, ATRA, and AZD.0530) than the low-risk group. These findings contribute to understanding of the function of m6A-related lncRNAs in UCEC and provide promising therapeutic strategies for UCEC.

Oleic acid, a monounsaturated fatty acid, exhibits antiproliferative and anti-tumorigenic effects in pre-clinical studies for endometrioid endometrial cancer (261)

<b>Objectives:</b> Oleic acid (OA), a monounsaturated fatty acid commonly found in olive oil, has been studied for its potential protective qualities in inflammatory conditions and cancers. In breast cancer cells, OA has been shown to reduce the expression of the oncogene <i>Her-2/ neu</i> and promote apoptosis. The relationship between the intake of olive oil and endometrial cancer risk and progression has been largely unexplored. Thus, we aimed to evaluate the effect of OA on cell proliferation and tumor growth in endometrial cancer cell lines and a transgenic mouse model of endometrial cancer. <b>Methods:</b> The human endometrioid endometrial cancer cell lines, ECC-1 and KLE, were exposed to varying concentrations of OA. Cell proliferation was assessed by MTT assay. Apoptosis was assessed by cleaved caspase-3, -8, and -9 assays. Cell cycle progression was measured by Cellometer. Cellular stress was measured by DCFH-DA assay. Mitochondrial membrane potential was assessed by TMRE assay. Western immunoblotting was performed to determine the effects of OA on BCL-xl, MCL-1, CDK4, CyclinD1, Calnexin, and Bip. The LKB1^fl/flp53^fl/fl mouse model of endometrioid endometrial cancer was used to determine the antitumorigenic activity of OA. The mice were treated with OA (10 mg/kg, oral gavage, daily) versus control for four weeks. <b>Results:</b> OA inhibited proliferation in a dose-dependent manner in both cell lines, with a 60% reduction at a dose of 500 µM in the ECC-1 cell line and 250 µM in the KLE cell line. OA at a dose of 200 µM significantly increased the activity of cleaved caspase-3, 8, and 9 by 2.2, 1.4, and 1.7-fold in the ECC-1 cells (p<0.05), respectively, and 1.4, 1.3, and 1.4-fold in the KLE cells (p<0.05), respectively. OA simultaneously decreased expression of Bcl-xl and MCL-1 in both cell lines. OA inhibited cell cycle progression by G1 phase arrest in both cell lines in a dose-dependent fashion (p=0.02) and decreased expression of the cell cycle-related proteins, CDK4, and cyclin D1. Treatment with OA significantly increased ROS production at doses of 50 and 200 µM (p<0.05) and induced Calnexin and Bip expression in both cell lines. TMRE assay showed decreased mitochondrial membrane potential with OA at doses of 50 and 200 µM (p<0.05). Treatment of LKB1^fl/flp53^fl/fl mice with OA was well-tolerated and reduced tumor weight by 53% compared with control mice (p<0.05). <b>Conclusions:</b> We found that OA, the main monounsaturated fatty acid of olive oil, had antiproliferative and antitumorigenic effects in endometrioid endometrial cancer. These findings provide a preclinical rationale for OA as a potential dietary intervention and therapeutic adjunct in endometrial cancer patients.

MiodesinTM Positively Modulates the Immune Response in Endometrial and Vaginal Cells.

Endometriosis presents high prevalence and its physiopathology involves hyperactivation of endometrial and vaginal cells, especially by bacteria. The disease has no cure and therapies aiming to inhibit its development are highly desirable. Therefore, this study investigated whether MiodesinTM (10 µg/mL = IC80; 200 µg/mL = IC50), a natural compound constituted by Uncaria tomentosa, Endopleura uchi, and astaxanthin, could exert anti-inflammatory and anti-proliferative effects against Lipopolysaccharides (LPS) stimulation in endometrial and Candida albicans vaginal cell lines. VK2 E6/E7 (vaginal) and KLE (epithelial) cell lines were stimulated with Candida albicans (1 × 107 to 5 × 107/mL) and LPS (1 μg/mL), respectively. MiodesinTM inhibited mRNA expression for Nuclear factor kappa B (NF-κB), ciclo-oxigenase 1 (COX-1), and phospholipase A2 (PLA2), beyond the C–C motif chemokine ligand 2 (CCL2), CCL3, and CCL5 in VK2 E6/E7 cells (p < 0.05). In addition, the inhibitory effects of both doses of MiodesinTM (10 µg/mL and 200 µg/mL) resulted in reduced secretion of interleukin-1β (IL-1β), IL-6, IL-8, tumor necrosis factor α (TNF-α) (24 h, 48 h, and 72 h) and CCL2, CCL3, and CLL5 (p < 0.05) by VK2 E6/E7 cells. In the same way, COX-1 MiodesinTM inhibited LPS-induced hyperactivation of KLE cells, as demonstrated by reduced secretion of IL-1β, IL-6, IL-8, TNF-α (24 h, 48 h, and 72 h) and CCL2, CCL3, and CLL5 (p < 0.05). Furthermore, MiodesinTM also inhibited mRNA expression and secretion of matrix metalloproteinase-2 (MMP-2), MMP-9, and vascular endothelial growth factor (VEGF), which are key regulators of invasion of endometrial cells. Thus, the study concludes that MiodesinTM presents beneficial effects in the context of endometriosis, positively affecting the inflammatory and proliferative response.

Blocking of EphA2 on Endometrial Tumor Cells Reduces Susceptibility to Vδ1 Gamma-Delta T-Cell-Mediated Killing

BackgroundEndometriosis is a common gynecological disease characterized by the presence of endometrial tissue outside the uterus causing chronic inflammation, severe pain, and infertility. However, the innate immunity of gamma-delta (γδ) T lymphocytes in endometriosis has not been characterized. Women with endometriosis present numerous endocrine and immune dysfunctions and elevated risk for endometrial, ovarian, and breast cancers. The tyrosine kinase EphA2 is often overexpressed in cancer including endometrial carcinoma.MethodsWe analyzed Vδ1 and Vδ2 γδ T cells in peripheral blood and paired peritoneal fluid samples in endometriosis patients (n = 19) and compared the counts with that of age- and sex-matched healthy donors (n = 33) using flow cytometry. Vδ1 and Vδ2 T cells isolated from healthy donors were used against KLE, RL-95, and Ishikawa endometrial tumor cells in 4 h flow cytometric cytotoxicity assays. The EphA2 blocking studies were performed using antibody, small-molecule inhibitor ALW-II-41-27, and the CRISPR/Cas9.ResultsWe determined Vδ1 T cells substantially reduced in patients’ peripheral blood (p < 0.01) and peritoneal fluid (p < 0.001). No differences were found for circulating Vδ2 T cells compared with peritoneal fluid samples. We observed inherent cytotoxic reactivity of Vδ1 and Vδ2 γδ T lymphocytes against endometrial tumor cells. Importantly, we found reduced specific lysis of EphA2-positive cell lines KLE and RL-95 by Vδ1 T cells in the EphA2 antibody blocking studies and by the EphA2 inhibitor. Furthermore, Vδ1 T-cell-mediated killing was significantly decreased in RL-95 cell EPHA2 knockout. Finally, potent cytolytic activity exerted by Vδ1 T cells was significantly reduced in EPHA2 knockouts in renal A-498 and colon HT-29 carcinoma cell lines.ConclusionsWe determined variable levels of Vδ1 and Vδ2 γδ T cells in endometriosis patients. We observed inherent cytotoxic reactivity of γδ T-cell subsets against endometrial cell lines. Specifically, we found that blocking of EphA2 expression resulted in significant inhibition of endometrial tumor killing mediated by Vδ1 γδ T cells. These results suggest that EphA2 is involved in tumor cell lysis and contributes to susceptibility to Vδ1 γδ T cells cytotoxic reactivity.

Evaluation of the efficacy and treatment sequence of paclitaxel and gemcitabine-loaded microparticles in a serous-like endometrial cancer cell line: a novel treatment strategy

<h3>Objectives:</h3> Uterine serous carcinoma (USC) presents a clinical challenge due its propensity to present at advanced stages, high recurrence rate and development of chemoresistance. The majority of patients with advanced disease will progress or recur following first-line platinum-based chemotherapy. As a result, new treatment strategies are urgently needed. Poly (lactic-co-glycolic acid)-based (PLGA) microparticles (MP) are a promising tool for delivery of chemotherapy due to prolonged drug elution over a period of several weeks, offering the benefit of sustained anti-cancer activity in the target tissue while limiting systemic toxicity. This is an attractive treatment strategy for USC, which can be accessed vaginally, allowing for the delivery of drug-loaded MP directly to the tumor. Previous work demonstrates paclitaxel and gemcitabine can be successfully loaded to PLGA-MP for drug delivery. <h3>Methods:</h3> The human endometrial cancer (EC) cell line KLE, representing a poorly differentiated serous-like EC was obtained from ATCC. Cells were treated with paclitaxel-loaded MP only (PMP), gemcitabine-loaded MP only (GMP), PMP-GMP sequence (PG), GMP-PMP sequence (GP) and PMP-GMP delivered concurrently (C). Blank MP (BMP) were used as control for each treatment. Cells were then collected at 6-days post-treatment for isolation of protein and assessment of cytotoxicity by cell viability assay. Protein lysates were analyzed for expression of multiagent chemoresistance protein AXL and paclitaxel resistance protein beta III tubulin (TUBB3) and apoptotic protein cleaved-PARP by Western Blot. <h3>Results:</h3> We observed morphologic changes and a decrease in cell density in all treatment regimens versus controls. These changes were most marked in the two-drug combination regimens. A significant increase in cleaved-PARP was observed in all treatments compared to controls. Chemoresistance proteins AXL and TUBB3 were not expressed in controls. AXL expression was increased in all treatment regimens. TUBB3 expression was significantly greater in PMP and GP regimens compared to PG (p=0.05). All treatment regimens were associated with a significantly decrease in cell viability versus controls (p<0.001). GMP containing regimens produced a greater decrease in cell viability compared to single agent paclitaxel. C treatment produced a significantly greater decrease in cell viability compared to all other regimens (p<0.001). <h3>Conclusions:</h3> PMP and GMP demonstrated significant cytotoxicity in a serous-like EC cell line. Concurrent PMP-GMP administration elicited the greatest decrease in cell viability. TUBB3 expression was markedly less when cells received PG, indicating the sequence of paclitaxel followed by gemcitabine may counteract paclitaxel resistance observed with single agent paclitaxel and alternate sequencing. Chemotherapy delivered via MP is an attractive treatment strategy for advanced and recurrent USC. Future <i>in vivo</i> studies are needed to validate this new treatment approach.

B3GNT3 acts as a carcinogenic factor in endometrial cancer via facilitating cell growth, invasion and migration through regulating RhoA/RAC1 pathway-associated markers.

Aberrant expression of beta-1,3-N-acetylglucosaminyltransferase-3 (B3GNT3) has been frequently clarified in various cancers, however, its role in endometrial cancer (EC) has not been assessed in detail. This study aimed to investigate the biological role of B3GNT3 in EC and simply explored the detailed mechanism. The EC RNA-Seq dataset from TCGA database was applied to evaluate the expression of B3GNT3 and assess its role on prognostic value. HEC-1-A and KLE cell lines of EC were used to perform loss- and gain-of-function B3GNT3 assays respectively. Quantitative real-time PCR (qRT-PCR) and western blot were used to measure the mRNA and protein levels of indicated molecules respectively. Cell counting kit-8, clone formation tests, and Transwell assay served to determine the changes of proliferative, invasive and migratory abilities of EC cells after altering the expression of B3GNT3. B3GNT3 was found to be highly expressed in EC tissues compared to normal tissues according to the online public databases, which confirmed by the following qRT-PCR in 3 EC cell lines. Besides, high B3GNT3 expression presented a worse overall survival in EC patients as compared with low B3GNT3 expression group. Furthermore, functional experiments in vitro indicated that B3GNT3 could facilitate the cell growth, invasion and migration. Moreover, we found that downregulation of B3GNT3 significantly reduced the expression level of GTP-RhoA and GTP-RAC1, whereas upregulation of B3GNT3 presented the opposite results. The results of current study demonstrate that B3GNT3 acts as an oncogene that promotes EC cells growth, invasion and migration possibly through regulating the RhoA/RAC1 signaling pathway-related markers, suggesting that B3GNT3 may be a candidate biomarker for EC therapeutic intervention.

Abstract PO042: ROR2 is epigenetically regulated in endometrial cancer

Abstract BACKGROUND: The Wnt signalling receptor ROR2 has been identified as a potential target in numerous cancers, however its exact role remains controversial. ROR2 has been shown to play distinct roles in regards to tumorigenesis in different tumour types. Our previous study suggested a potential tumour suppressor role for ROR2 in endometrial cancer (EC), however the mechanism associated with ROR2 repression in EC remains unclear. ROR2 has been found to be epigenetically inactivated in colorectal cancer. OBJECTIVE: The aim of this study was to investigate the role of ROR2 in EC, and to determine if ROR2 expression in EC was regulated epigenetically. METHODS: The correlation between ROR2 mRNA expression levels and clinicopathological parameters, including overall survival (OS) was analysed in The Cancer Genome Atlas Uterine Corpus Endometrial Carcinoma (TCGA-UCEC, n=546) cohort and GEO datasets (GSE17025, n=91). Immunohistochemistry (IHC) of ROR2 was performed on a large EC patient cohort (Australia-wide population-based Australian EC Study, ANECS, n=499). The correlation between ROR2 staining intensity (0-3) and clinicopathological parameters as well as 5-year progression free survival (PFS) and OS was analysed. Cox regression was also applied to analyse the impact of selected covariates (age, BMI, FIGO stage and grade) on the PFS and OS. Four EC cell lines (KLE, MFE-296, Ishikawa and ARK-1) and eight clinical EC samples were analysed for ROR2 methylation via COmbined Bisulphite Restriction Analysis (COBRA) and bisulphite genomic sequencing (BGS). RESULTS: ROR2 promoter methylation or reduced ROR2 expression were both found to correlate with lower OS, high grade and serous EC in the TCGA-UCEC and GEO dataset at p&amp;lt;0.05 level. In our ANECS cohort, the same trend of correlation was observed of ROR2 expression and grade (p=0.062). No significant correlation was observed for ROR2 expression with OS or PFS in this cohort at univariate or multivariable survival analysis. ROR2 was epigenetically silenced by promoter methylation in KLE and ARK-1 cell lines. There was also a significant correlation between ROR2 expression level and promoter methylation in our patient cohort (r=-0.79, p=0.02). CONCLUSION: ROR2 plays a tumour suppressor role in EC and is epigenetically suppressed with the development of disease. It may therefore be a diagnostic or therapeutic candidate for EC. Citation Format: Dongli Liu, Luis Enriquez, Benjamin Daniels, Tracy O'Mara, Katrina Tang, Caroline Ford. ROR2 is epigenetically regulated in endometrial cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PO042.

Biogenesis of copper nanoparticles (Cu-NPs) using leaf extract of Allium noeanum, antioxidant and in-vitro cytotoxicity

In this research, we formulated new chemotherapeutic copper nanoparticles (Cu NPs) containing Allium noeanum Reut. ex Regel leaf for treating human endometrial cancer. For investigating the antioxidant activitiy, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test was used. MTT test was used on normal (Human umbilical vein endothelial cells (HUVECs)) and human endometrial cancer (Ishikawa, HEC-1-A, HEC-1-B, and KLE) cell lines for comparing the anti-human endometrial cancer properties of Cu(NO3)2, A. noeanum leaf aqueous extract, and copper nanoparticles. Copper nanoparticles had high cell death and anti-human endometrial cancer effects against Ishikawa, HEC-1-A, HEC-1-B, and KLE cell lines. The IC50 of A. noeanum leaf aqueous extract and copper nanoparticles against HEC-1-B cell line were 548 and 331 µg/mL, respectively; against HEC-1-A cell line were 583 and 356 µg/mL, respectively; against KLE cell line were 609 and 411 µg/mL, respectively; and against Ishikawa cell line were 560 and 357 µg/mL, respectively. Among the above cell lines, the best result of anti-human endometrial cancer properties of copper nanoparticles was gained in the cell line of HEC-1-B. This study indicated excellent anti-human endometrial cancer potentials of copper nanoparticles containing A. noeanum in the in vitro condition.

Abstract 2942: ROR1: A novel target in endometrial cancer

Abstract Background Endometrial cancer is one of the fastest rising cancers in women, and despite overall high survival, new therapies are required for women with aggressive subtypes of the disease. ROR1 and ROR2 are Wnt receptor tyrosine kinases whose expression is altered in a range of cancers. This study aimed to investigate the role of ROR1/2 in endometrial cancer (EC). Method Immunohistochemistry (IHC) of ROR1 and ROR2 was performed on an EC patient cohort (Australia-wide population-based Australian EC Study, ANECS, n=499). The association between ROR1/2 staining intensity (0-3) and clinicopathological parameters was analyzed, as well as association with 5-year progression free survival (PFS) and overall survival (OS). Cox multivariate regression was also applied to analyze the impact of selected covariates (age, BMI, FIGO stage, grade and subtypes) on the PFS and OS. The functional effect of ROR1 and ROR2 modulation was further investigated in two EC cell lines–KLE (high ROR1, low ROR2) and MFE-296 (low ROR1, high ROR2). For KLE, ROR1 silencing and ROR2 overexpression were performed. In contrast, ROR2 silencing and ROR1 overexpression were performed in MFE-296. ROR1 or ROR2 silencing was achieved via transfection with ROR1 or ROR2 siRNA. ROR1 pCMV3 plasmid or ROR2 pFLAG plasmid were transfected for ROR1 or ROR2 overexpression. All the conditions were compared to the negative control which was prepared by transfecting both non-targeting siRNA and pCMV3-NH plasmid. Effects on proliferation, adhesion, migration and invasion were measured. Result In the patient cohort, ROR1 expression level was significantly associated with tumor grade (p=0.004) and moderately associated with FIGO stage (p=0.057). A significant decrease in OS and PFS was observed in patients with high ROR1 expression (p=0.045 and 0.003 respectively). This correlation was not lost when filtering against multiple parameters including age, BMI, FIGO stage and tumor grade in COX regression (p=0.049). No significant correlation was observed for ROR2 expression with OS or PFS, though high ROR2 showed a trend towards better PFS. ROR1 downregulation or ROR2 upregulation in KLE cells decreased cell proliferation after 72 hours. The combination of the two further reduced cell proliferation significantly after 48h and 72h (p=0.04 and 0.004 respectively). Proliferation was not significantly altered in MFE-296, although ROR1 overexpression showed a trend for increasing cell proliferation after 72h. ROR1 silencing in KLE decreased the migration ability moderately (p=0.059) and its combination with ROR2 overexpression further reduced migration significantly (p=0.038). No significant change in invasion or adhesion was observed. Conclusion This study confirms the oncogenic role ROR1 plays in EC, which warrants the future application of ROR1-targeting therapies in EC patients. The role of ROR2 is more complex in EC and may be context dependent. Citation Format: Dongli Liu, Kate Gunther, Benjamin Daniels, Tracy O'Mara, Katrina Tang, Australian National Endometrial Cancer Study Group, Caroline Ford. ROR1: A novel target in endometrial cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2942.

Actin‑like protein 8 executes a promoting function in the malignant progression of endometrial cancer: identification of a promising biomarker.

Endometrial cancer (EC) is generally considered as a disease that affects older women. We attempt to explore the role of actin‑like protein 8 (ACTL8) in EC and how it achieves its function. Based on the data from The Cancer Genome Atlas (TCGA), we found that ACTL8 expression was up-regulated in EC tissues and correlated with shorter overall survival of EC patients. ACTL8 expression was significantly associated with age, clinical-stage, or grade. Cox proportional hazards model analysis revealed that ACTL8 expression, grade, and clinical-stage were promising independent prognostic factors of EC. Knockdown of ACTL8 repressed the proliferative, migrating and invading capabilities of human EC cell lines KLE and Ishikawa. Silencing ACTL8 up-regulated the negative cell cycle regulator p21 and epithelial marker E-cadherin, and down-regulated the positive cell cycle regulator Cyclin A, mesenchymal markers MMP-9 and N-cadherin in KLE cells. Collectively, these outcomes illustrated that ACTL8 might act as a tumor facilitator during EC progression.

Repurposing of antipsychotics perphenazine for the treatment of endometrial cancer

Endometrial cancer (EC) is one of the most common and fatal gynecological cancers worldwide, but there is no effective treatment for the EC patients of progesterone resistance. Repurposing of existing drugs is a good strategy to discover new candidate drugs. In this text, perphenazine (PPZ), approved for psychosis therapy, was identified as a potential agent for the treatment of both progesterone sensitive and resistant endometrial cancer for the first time. Specifically, perphenazine exhibited good cell proliferation inhibition in Ishikawa (ISK) and KLE cell lines according to the CCK-8 assay and colony formation assay. It also reduced the cell migration of ISK and KLE cell lines in the light of the transwell migration assay. Annexin-V/PI double staining assay suggested that perphenazine could effectively induce ISK and KLE cell apoptosis. Moreover, results of western blot assay indicated perphenazine obviously inhibited the phosphorylation of Akt. Delightedly, PPZ also could significantly attenuate xenograft tumor growth at both 3 mg/kg and 15 mg/kg in mice without influencing the body weights.

Picropodophyllin inhibits type I endometrial cancer cell proliferation via disruption of the PI3K/Akt pathway.

The type-I insulin-like growth factor receptor (IGF-IR) is overexpressed in endometrial cancer. High IGF-IR expression was considered as an important prognostic factor for tumor progression. The purpose of this study was to investigate the role and molecular mechanism of IGF-IR inhibitor picropodophyllin (PPP) in the growth and development of endometrial cancer. High expression of IGF-IR was observed in endometrial cancer tissues, as well as in ECC-1 and KLE cell lines. PPP suppressed the number of clones of ECC-1 and KLE cell lines; however, it had no significant effect on HEC-1-A cell line, which expressed lower IGF-IR than ECC-1 and KLE cell lines. Furthermore, PPP reduced cell proliferation capacity, inhibited the IGF-IR mRNA expression, and suppressed protein phosphorylation of IGF-IR and Akt in the three cell lines. In addition, PPP inhibited the protein expression of survivin in KLE cell line after 1h of exposure, though this effect did not last for prolonged time. In conclusion, IGF-IR was mostly overexpressed in type I endometrial cancer. High IGF-IR expression was an important prognostic factor of tumor progression. PPP mediated the down-regulation of IGF-IR phosphorylation and inhibited cell proliferation via the PI3K/Akt signal pathway. PPP may have the potential to become a clinical treatment target in endometrial carcinoma.

Interactions between microRNA-200 family and Sestrin proteins in endometrial cancer cell lines and their significance to anoikis

In the present study, we intend to determine whether Sestrin proteins 1, 2, and 3 (SESN1-3) are targets of microRNA-200 family (miR-200) in endometrial cancer (EC) Ishikawa, AN3CA, KLE, and RL 95-2 cell lines and to investigate how these potential interactions influence anoikis resistance of EC cell lines. The luciferase reporter assay, qRT-PCR, and western blotting assays were used to verify whether SESN1-3 are direct targets of miR-200. Moreover, the anoikis assay and transient transfections of miR-200 mimics or inhibitors into EC cell lines were performed to evaluate the modulatory role of miR-200 and SESN proteins on anoikis resistance. We demonstrated that SESN2 protein is a direct target of mir-141 in KLE and RL-95-2 EC cell lines and the functional interaction of miR-141 and SESN2 protein has a downstream effect on anoikis resistance and SESN2 expression level in Ishikawa and AN3CA cell lines. Moreover, we have shown that SESN3 protein is a direct target of miR-200b, miR-200c, and miR-429 in Ishikawa, AN3CA, and KLE cell lines. Our results show that manipulation of miR-200b, miR-200c, and miR-429 expression patterns also has an influence on anoikis resistance in EC cell lines. In conclusion, we identified new interactions between miR-200 and the oxidative stress response SESN proteins that affect anoikis resistance in human EC cells.

Effect of apoptosis and proliferation of endometrial cancer HEC-1B cell by siRNA down-regulating expression of Ezrin

Objective To observe the changes of cell cycle, apoptosis and proliferation of endometrial cancer cells after the expression and down-regulation of Ezrin in endometrial cancer cells and to explore whether Ezrin may be a candidate gene for targeted therapy. Methods Endometrial cancer cells were from Shanghai Institute of Cell Research, of Chinese Academy of Medical Sciences in February 2017 and divided into blank control group and siEzrin group according to the intervention methods.Western blot and qRT-PCR was used to detect the expression of Ezrin protein and mRNA in endometrial cell lines.Small interfering RNA(siRNA) was used to transfect HEC-1B cell and down-regulate Ezrin.Cell cycle and apoptosis were detected by flow cytometry.MTT assay was used to detect multiplication. Results Western blot showed that Ezrin protein was expressed in Ishikawa(31.742±5.832)、HEC-1A(16.326±3.135)、HEC-1B(17.636±4.426) and KLE(14.862±5.109) and qRT-PCR showed that mRNA was expressed in Ishikawa (2.513±0.725), HEC-1A (1.655±0.692), HEC-1B (3.237±0.411) and KLE (0.962±0.235) cell lines, and expressed highest in HEC-1B cells (F=6.173, P<0.05; F=7.042, P<0.05). Flow cytometry assay showed that compared with blank control group less cells stayed in G1 phase and G2 phase, more stayed in S phase (t=3.118, P<0.05; t=5.435, P<0.05; t=3.332, P<0.05). The apoptotic rate of HEC-1B cells increased from (9.84±2.37)% to (17.64±5.96)%(t=8.963, P<0.01) after Ezrin was down-regulated.MTT assay showed that the proliferation of HEC-1B cells in 72 h and 96 h siEzrin transfection group was lower than that in blank control group (t=3.209, P<0.05; t=3.726, P<0.05). Conclusion Down-regulating of Ezrin may promote more endometrial cancer cells stay in S phase and promote apoptosis, inhibit proliferation, Ezrin may become target candidate gene in target therapy. Key words: Endometrial cancer; Ezrin protein; Cell cycle; Apoptosis; Proliferation

CP‑31398 attenuates endometrial cancer cell invasion, metastasis and resistance to apoptosis by downregulating MDM2 expression.

Endometrial cancer (EC) is one of the most common malignancies of the female reproductive system, and metastasis is a major cause of mortality. In this study, we aimed to explore the role of CP-31398 in the migration, invasion and apoptosis of EC cells by its regulation of the expression of the murine double minute 2 (MDM2) gene. For this purpose, EC tissues and adjacent normal tissues were collected, and the positive expression rate of MDM2 in these tissues was assessed. Subsequently, the cellular 50% inhibitory concentration (IC50) of CP-31398 was measured. The EC RL95-2 and KLE cell lines had a higher MDM2 expression and were thus selected for use in subsequent experiments. The EC cells were then treated with CP-31398 (2 µg/ml), and were transfected with siRNA against MDM2 or an MDM2 overexpression plasmid in order to examine the effects of CP-31398 and MDM2 on EC cell activities. The expression of p53, p21, Bad, Bax, B-cell lymphoma-2 (Bcl-2), cytochrome c (Cyt-c), caspase-3, Cox-2, matrix metalloproteinase (MMP)-2 and MMP-9 was measured to further confirm the effects of CP-31398 on cell migration, invasion and apoptosis. Our results indicated that MDM2 was highly expressed in EC tissues. Notably, EC cell viability decreased with the increasing concentrations of CP-31398. The EC cells treated with CP-31398 or siRNA against MDM2 exhibited an increased apoptosis and a suppressed migration and invasion, corresponding to an increased expression of p53, p21, Bad, Bax, Cyt-c and caspase-3, as well as to a decreased expression of Bcl-2, Cox-2, MMP-2 and MMP-9. Moreover, treatment with CP-31398 and siRNA against MDM2 further enhanced these effects. Taken together, the findings of this study indicate that the CP-31398-mediated downregulation of MDM2 may suppress EC progression via its inhibitory role in EC cell migration, invasion and resistance to apoptosis. Therefore, treatment with CP-31398 may prove to be possible therapeutic strategy for EC.

Expression of tumor suppressor programmed cell death 4 in endometrioid endometrial carcinomas and clinicopathological significance.

Programmed cell death 4 (PDCD4), as a novel tumor suppressor, serves important roles in the pathogenesis of tumors. The expression of PDCD4 is downregulated or lost in various human tumors. However, the expression of PDCD4 in endometrial cancer and the clinicopathological significance remain unclear. The aim of the present study was to investigate the expression of PDCD4 in endometrioid endometrial carcinoma (EEC) and the association with clinicopathological parameters. The expression of PDCD4 in EEC tissues and control endometrium was detected by reverse transcription-quantitative polymerase chain reaction, western blotting and immunohistochemistry. PDCD4 expression was also investigated in control endometrial glandular epithelial cells and the endometrial cancer KLE cell line by immunocytochemistry, and the association between PDCD4 expression and clinicopathological parameters of patients with EEC was analyzed. The results demonstrated that PDCD4-positive staining was mainly located in the cytoplasm of endometrial glandular epithelial cells and EEC cells. The staining index of PDCD4 in the proliferative phase was significantly increased compared with that in the secretory phase of control endometrium (P<0.001). There was significantly decreased PDCD4 expression in grade (G) 2/3 EEC tissues compared with the proliferative phase of control endometrium (P<0.001). PDCD4 expression was significantly associated with tumor grade. The PDCD4 levels in G1 EEC tissues were higher compared with the G2/3 EEC group (P<0.01). The results indicated that PDCD4 is associated with the histological grade of EEC, and that PDCD4 may be a valuable indicator of the degree of tumor malignancy in patients with EEC.

Abstract 3229: Drug repurposing of topiramate in obesity-driven endometrial cancer

Abstract Introduction: Topiramate (TPM) is a B-D-fructopyranose sulfamate that acts by inhibiting carbonic anhydrases (CAs) and has been implicated as a novel inhibitor of angiogenesis. TPM is commonly used for the treatment of epilepsy and migraine headaches; however, when combined with phentermine, TPM can induce weight loss. Due to its weight loss and anti-angiogenic properties, we assessed TPM’s potential as an anti-tumorigenic agent in endometrial cancer (EC), a highly obesity-driven disease. Methods: Cell proliferation was assessed by MTT assay after exposure to TPM for 72 hours in the HEC-1A, KLE, Ishikawa and ECC-1 EC cell lines. Two representative cell lines, ECC-1 and Ishikawa, were used to analyze apoptosis, cell cycle progression, cell adhesion and invasion. Apoptosis was analyzed by Annexin V-FITC assay. Inhibition of adhesion and invasion by TPM were assessed by ELISA and transwell assay, respectively. Cell cycle progression was evaluated by Cellometer. Western immunoblotting was performed to assess downstream targets of the MAPK and mTOR pathways. The LKB1fl/flp53fl/fl EC mouse model was utilized to assess the in vivo effects of TPM. AdCre was injected at six weeks of age to induce invasive EC. Eight wks following AdCre injection, mice (N=10 per group) were treated with placebo or TPM (200 mg/kg/day, oral) for four weeks. The expression of phosphorylated-S6 and Ki-67 was assessed by IHC. Results: TPM inhibited cell proliferation in a dose dependent manner in all four EC cell lines (IC50 range=1500-3000 mM). Treatment with TPM resulted in G1 arrest and induction of apoptosis (p&amp;lt;0.05). TPM also reduced adhesion and invasion in the EC cell lines (p=0.05), with a corresponding decrease in VEGF expression. In addition, TPM significantly inhibited phosphorylation of p42/44 and S6 in the EC cell lines. Lastly, TPM decreased tumor weight in the LKB1fl/flp53fl/fl mice by 68% compared to those treated with placebo (p&amp;lt;0.05), accompanied by a reduction in Ki-67 and phosphorylated-S6 expression (p&amp;lt;0.05). Conclusion: TPM inhibited cell proliferation and tumor growth in EC cell lines and an EC mouse model. Therefore, TPM may be worthy of drug repurposing as an anti-tumorigenic agent in EC, with the potential added benefit of weight loss in this obesity-linked disease. Citation Format: Arthur-Quan Tran, Stephanie A. Sullivan, Chunxiao Zhou, David Kaufman, Victoria Bae-Jump. Drug repurposing of topiramate in obesity-driven endometrial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3229. doi:10.1158/1538-7445.AM2017-3229