Apoptosis In Endometrial Cancer Research Articles

UBE2J1 knockdown promotes cell apoptosis in endometrial cancer via regulating PI3K/AKT and MDM2/p53 signaling.

Emerging evidence has demonstrated that ubiquitin conjugating enzyme E2 J1 (UBE2J1) exerts pivotal function in many cancers. UBE2J1 was reported to be dysregulated in endometrial cancer (EC). This study was designed to further investigate the regulatory character and mechanism of UBE2J1 in EC. Bioinformatic tools and databases were used to analyze gene expression pattern and gene expression correlation in EC tissues, and the prognosis of EC patients. Gene expression was evaluated by reverse-transcription quantitative polymerase chain reaction. Western blot was used for protein level detection. In vitro cell apoptosis was detected by flow cytometry analyses and TUNEL assays. In vivo cell apoptosis was evaluated by detecting Bax and Bcl-2 expression in tumor tissues via immunohistochemical and western blot analyses. In this study, UBE2J1 knockdown promoted cell apoptosis in EC cells and in mouse models of EC. PI3K and AKT expression is positively correlated with UBE2J1 level and is related to poor prognosis of EC patients. UBE2J1 knockdown repressed the PI3K/AKT pathway both in vitro and in vivo. UBE2J1 downregulation decreased MDM2 expression, but increased p53 expression. MDM2 overexpression reverses the promotion of UBE2J1 knockdown on cell apoptosis in EC. Overall, UBE2J1 knockdown induces cell apoptosis in EC by inactivating the PI3K/AKT signaling and suppressing the MDM2/p53 signaling.

Stanniocalcin 2 is induced by estrogen and promotes growth in endometrial cancer via AMPK pathway.

Stanniocalcin 2 (STC2) is identified as a glycosylated peptide hormone and estrogen-responsive gene in cancer cells. STC2 participates in angiogenesis, cell development, cytoprotection, and calcium and phosphate regulation during the development of cancer. The role of STC2 in endometrial cancer (EC) remains unclear. The data from the bioinformatic and immunohistochemical analysis showed that STC2 was upregulated in the EC tissues. The EC cells were treated with 17β-estradiol (E2), and 0.1 μmol/L E2 increased the expression of STC2 in the EC cells. E2 also increased cell viability, promoted proliferation, and inhibited apoptosis of EC. However, the knockdown of STC2 decreased cell viability, reduced proliferation, and promoted apoptosis of E2-stimulated EC. Moreover, silencing of STC2 attenuated E2-induced downregulation of phosphorylated-AMP-activated protein kinase (AMPK) in the EC cells. The loss of STC2 reduced E2-stimulated tumor growth EC in vivo. In conclusion, STC2 deficiency suppressed E2-stimulated proliferation and tumor growth of EC through the activation of AMPK signaling.

Retracted: lncRNA NBAT1 Inhibits Cell Metastasis and Promotes Apoptosis in Endometrial Cancer by Sponging miR-21-5p to Regulate PTEN.

[This retracts the article DOI: 10.1155/2022/9304392.].

LncRNA NBAT1 Inhibits Cell Metastasis and Promotes Apoptosis in Endometrial Cancer by Sponging miR-21-5p to Regulate PTEN.

Objective Long noncoding RNA neuroblastoma-associated transcript 1 (NBAT1) is implicated in the progression of various cancers. Nevertheless, its biological function in endometrial cancer (EC) remains unknown. Methods The levels of NBAT1, miR-21-5p, and PTEN in EC cells and EC tissues were examined by RT-qPCR. Western blot was carried out to assess the protein expression of PTEN. The dual-luciferase reporter assay was conducted to explore the interactions among NBAT1, miR-21-5p, and PTEN. The effect of NBAT1 on EC proliferation, metastasis, and apoptosis was evaluated by CCK-8, transwell assays, wound healing, and flow cytometry. miR-21-5p mimics or NBAT1+miR-21-5p were transfected into HEC-1A and Ishikawa cells to investigate whether NBAT1 regulated EC tumorigenesis via sponging miR-21-5p. Results NBAT1 is downregulated, and miR-21-5p is upregulated in EC cells and tumor tissues. Overexpression of NBAT1 inhibits the proliferation, migration, and invasion abilities of EC cells and facilitated apoptosis. NBAT1 directly binds and negatively regulates miR-21-5p in EC. miR-21-5p mimics reverses the effect of lncRNA NBAT1 overexpression on the proliferation and migration of EC cells. PTEN is a downstream gene of miR-21-5p. lncRNA NBTA1 elevates PTEN expression via sponging miR-21-5p. Conclusions lncRNA NBAT1 acts as a tumor suppressor in EC via regulating PTEN through sponging miR-21-5p.

Histone arginine methyltransferase CARM1 selective inhibitor TP-064 induces apoptosis in endometrial cancer

Histone modification is the key epigenetic mechanism that regulates gene expression. Coactivator-associated arginine methyltransferase 1 (CARM1) is an arginine methyltransferase that catalyzes dimethylation of histone H3 (H3R17) at arginine 17. Lately, it has been suggested that CARM1 is associated with human carcinogenesis, and the CARM1-selective inhibitor, TP-064, has been shown to be a potential therapeutic agent for multiple myeloma. However, the physiological significance of CARM1 in endometrial cancer remains unclear. Therefore, we aimed to explore the role of CARM1 and the effect of TP-064 in endometrial cancer. To this end, we analyzed CARM1 expression in endometrial cancer using quantitative real-time polymerase chain reaction and examined the antitumor mechanism with CARM1 knockdown endometrial cancer cells. Moreover, we evaluated the therapeutic capability of TP-064 in endometrial cancer cells. CARM1 was remarkably overexpressed in 52 endometrial cancer tissues compared to normal endometrial tissues. The growth of CARM1 knockdown endometrial cancer cells was suppressed and CARM1 knockdown induced apoptosis. TP-064 also inhibited endometrial cancer cell growth and declined the number of endometrial cancer cell colonies. These data suggest that CARM1 may be a powerful therapeutic target for endometrial cancer.

SMC4 knockdown inhibits malignant biological behaviors of endometrial cancer cells by regulation of FoxO1 activity

Structural maintenance of chromosomes 4 (SMC4) has an important role in chromosome condensation and segregation, which is involved in regulating multiple tumor development. However, the role of SMC4 in endometrial cancer is uncertain. The expression and prognostic value of SMC4 were predicted by UALCAN, Gene Expression Omnibus (GEO), The Human Protein Atlas and Kaplan Meier plotter tools. SMC4-related genes were analyzed by LinkedOmics, Gene Ontology (GO) annotations, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Forkhead box protein O1 (FoxO1) activity was suppressed by AS1842856 (AS). SMC4, Ki67, B-cell lymphoma-2(Bcl-2), Bcl-2 associated X protein (Bax), FoxO1, phosphorylated FoxO1 (p-FoxO1), and p27 protein levels were detected by Western blotting. Cell proliferation was detected using Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2′-deoxyuridine (EdU) analyses. Cell apoptosis was measured using TUNEL analysis. SMC4 abundance was increased in endometrial cancer, and predicted a worse overall survival. SMC4 knockdown repressed proliferative ability of endometrial cancer cells and promoted cell apoptosis. SMC4 knockdown promoted FoxO1 transactivation by decreasing its phosphorylated level. Addition of AS inhibited FoxO1 activity by increasing the phosphorylated level of FoxO1. The inhibition of FoxO1 activity reversed the effect of SMC4 silencing on cell proliferation and apoptosis. In conclusion, SMC4 silencing restrained cell proliferation and facilitated apoptosis in endometrial cancer via regulating FoxO1 activity.

MiR-101 reduces cell proliferation and invasion and enhances apoptosis in endometrial cancer via regulating PI3K/Akt/mTOR.

PI3K/Akt/mTOR signaling pathway plays an important role in tumor development. mTOR overexpression and PI3K/ Akt/mTOR signaling pathway enhancement were found in endometrial cancer (EC). MiR-101 was found downregulated in EC. Bioinformatics analysis showed the binding site between miR-101 and the 3'-UTR of mTOR mRNA. This study investigated the role of miR-101 in affecting EC proliferation, apoptosis, and invasion, and mediating mTOR expression. EC tumor tissue and normal endometrial tissue were collected from Jinan maternity and child care hospital. MiR-101 and mTOR expressions were detected. The targeted relationship between miR-101 and mTOR was tested by dual-luciferase reporter gene assay. MiR-101, mTOR, p-mTOR, and p-4EBP1 expressions between HEEC and HEC-1A cells were compared. HEC-1A cells were cultured in vitro and divided into five groups, including miR-NC, miR-101 mimic, si-NC, si-mTOR, and miR-101 + si-mTOR. mTOR, p-mTOR, and p-4EBP1 expressions were compared. Cell apoptosis was evaluated by flow cytometry. Cell malignant proliferation was evaluated by colony formation assay. Cell invasion was determined by Transwell assay. MiR-101 and mTOR expressions significantly declined in EC tissue compared with normal endometrium. MiR-101 showed targeted relationship with mTOR. MiR-101 reduced, while mTOR, p-mTOR, and p-4EBP1 levels elevated in HEC-1 cells compared with HEEC cells. MiR-101 mimic and/or si-mTOR transfection obviously reduced mTOR, p-mTOR, and p-4EBP1 expressions, decreased colony formation, decreased invasion, and enhanced apoptosis in HEC-1A cells. MiR-101 downregulated and mTOR elevated in EC tissue. MiR-101 decreased HEC-1A cell proliferation and invasion, and upregulated apoptosis through targeting mTOR to attenuate PI3K/Akt/ mTOR signaling pathway activity.

MiR-326 regulates the proliferation and apoptosis of endometrial cancer by targeting Bcl-2.

MiR-326 has been investigated to be correlated with multiple types of malignancies; however, the role of miR-326 in endometrial cancer (EC) remains rarely reported. The aim of our research is to investigate the functions of miR-326 in EC and the potential molecular mechanism. RT-qPCR was performed to compare the expression of miR-326 and Bcl-2 in normal endometrial epithelial cell line (End1/e6e7) and EC cells lines (HEC-1A, Ishikawa), respectively. Bioinformatic analysis and luciferase assay verified the relationship between miR-326 and the 3'-UTR of Bcl-2. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, soft agar colony formation assay and the flow cytometry were performed to investigate the functions of miR-326 and Bcl-2 on proliferation and apoptosis in EC. Western blotting was employed to explore the expression of Bcl-2, Bcl2-associated X (Bax) and caspase-3. The expression of miR-326 decreased in EC cell lines compared to normal endometrial epithelial cell line, while Bcl-2 expression was increased in EC cells. Results of MTT and soft agar colony formation assays showed that miR-326 suppressed proliferation in EC cells. In addition, flow cytometry revealed that miR-326 promoted apoptosis in EC cells. Western blotting showed that silencing miR-326 promoted the expression of Bcl-2. Bioinformatics analysis and luciferase assay verified the 3'-UTR of Bcl-2 was a target of miR-326. Furthermore, MTT assay, soft agar colony formation assay and the flow cytometry proved that miR-326 acts as tumor suppressor via inhibiting the expression of Bcl-2. MiR-326 acts as a cancer suppressor to inhibit proliferation and promote apoptosis via targeting Bcl-2 axis in EC.

Overexpression of Nuclear Enriched Autosomal Transcript 1 Facilitates Cell Proliferation, Migration Invasion, and Suppresses Apoptosis in Endometrial Cancer by Targeting MicroRNA-202-3p/T Cell Immunoglobulin and Mucin Domain 4 Axis

Background: Endometrial cancer (EC) is an intractable gynecological cancer with increasing incidence and mortality worldwide. Accumulating studies indicated that long noncoding RNA nuclear enriched autosomal transcript 1 (NEAT1) was a novel oncogene implicated in a variety of cancers. However, whether NEAT1 could accelerate cell growth in EC is unclear. Materials and Methods: NEAT1, microRNA (miR)-202-3p, and T cell immunoglobulin and mucin domain 4 (TIMD4) levels were detected by quantitative real-time polymerase chain reaction. Cell proliferation and apoptosis were examined by cell counting kit-8 and flow cytometry. Transwell assay was employed for the evaluation of cell migration and invasion. The relationship between miR-202-3p and NEAT1 or TIMD4 was determined by luciferase reporter system. TIMD4 protein expression was assessed by Western blot assay. Results: NEAT1 was upregulated, whereas miR-202-3p was downregulated in EC tumors and cells. Depletion of NEAT1 restrained EC cell proliferation, migration, invasion, and improved apoptosis. MiR-202-3p was targeted by NEAT1 and could bind to TIMD4. Subsequently, it is observed that miR-202-3p inhibitor neutralized NEAT1 silencing mediated suppression on EC cell progression. Meanwhile, TIMD4 rescued miR-202-3p induced inhibition on cell progression in EC. Furthermore, it was obvious that NEAT1 facilitated TIMD4 expression by absorbing miR-202-3p in EC. Conclusions: Upregulation of NEAT1 accelerated EC cell progression through sponging miR-202-3p to facilitate TIMD4 expression, providing potential novel treatment method for EC.

Targeting CDK9: A novel biomarker inthetreatment of endometrial cancer.

Endometrial cancer is one of the three major malignant tumors of the female reproductive system. Although cyclin-dependent kinase 9 (CDK9) has a definitive pathogenic role in various types of cancer, little is known concerning its function in endometrial cancer. Our study was conducted to evaluate the expression and therapeutic potential of CDK9 in endometrial cancer. CDK9 expression was determined by immunohistochemistry in endometrial cancer tissues constructed with paired primary, metastatic, and recurrent tumor tissues from 32 endometrial cancer patients. Small interfering RNA (siRNA) and inhibitors of CDK9 were used to evaluate the effect of CDK9 inhibition on the anti-apoptotic activity and proliferation in endometrial cancer cells. Colony formation assay and wound-healing assays were adopted to assess clonal formation and migratory capacity. The results of the immunohistochemistry demonstrated that CDK9 was highly expressed in the human endometrial cancer cell lines; moreover, it was elevated in metastatic and recurrent endometrial tumor tissue compared when compared with that in patient-matched primary endometrial tumor tissue. Knockdown of CDK9 with siRNA and inhibition of CDK9 activity with the inhibitor suppressed cell proliferation and promoted apoptosis in endometrial cancer. In conclusion, our results provide evidence that CDK9 may be a potential prognostic biomarker and a promising therapeutic target for the treatment of endometrial cancer in the future.

CircRNA hsa_circRNA_0001776 inhibits proliferation and promotes apoptosis in endometrial cancer via downregulating LRIG2 by sponging miR-182

BackgroundEndometrial cancer (EC) is a common malignancy of the female reproductive system. Circular RNAs (circRNAs) were demonstrated to exert critical roles in cancers, including EC. This study aimed to investigate the effects of hsa_circRNA_0001776 (circ_0001776) on EC.MethodsReal-time quantitative PCR (RT-qPCR) was used to measure circ_0001776, microRNA-182 (miR-182) and leucine-rich repeats and immunoglobulin-like domains 2 (LRIG2) expression. The diagnostic and prognostic values of circ_0001776 were identified by receiver operating characteristic (ROC) curve analysis and survival analysis, respectively. RNase R digestion was used to characterize circ_0001776, and the localization of circ_0001776 was evaluated by cell fractionation assay. Then, cell counting kit-8 (CCK-8), colony formation, and flow cytometry analysis were used to detect cell proliferation and apoptosis, respectively. The real-time glycolytic rate (ECAR) and lactate production were measured by extracellular flux analysis and a lactate assay kit, respectively. Bioinformatics analysis and dual-luciferase reporter assay were used to determine the interaction among circ_0001776, miR-182 and LRIG2. The protein expression of LRIG2 was determined by western blot. Moreover, circ_0001776 overexpression vector was used to upregulate circ_0001776 expression in an animal tumor model.ResultsCirc_0001776 and LRIG2 were downregulated, while miR-182 was upregulated in EC tissues and cells. Low expression of circ_0001776 was correlated with the 5-year survival rate of EC patients. Upregulated circ_0001776 markedly attenuated cell proliferation and glycolysis, and enhanced cell apoptosis. Besides, circ_0001776 sponged miR-182 to regulate LRIG2 expression. Circ_0001776 could suppress EC progression by miR-182/LRIG2 axis. Furthermore, we also found that circ_0001776 significantly inhibited tumor growth in vivo.ConclusionOur results confirmed that circ_0001776 inhibited EC tumorigenesis and progression via miR-182/LRIG2 axis, providing a potential therapeutic target for EC.

LncRNA ROR promotes proliferation of endometrial cancer cells via regulating Notch1 pathway.

The aim of this study was to investigate the effects of long non-coding ribonucleic acid regulator of reprogramming (lncRNA ROR) on the proliferation and apoptosis of endometrial cancer (EC) cells, and to explore its possible underlying mechanism. The expression levels of lncRNA ROR and Notch1 in EC tissues were detected via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The changes in Notch1 protein were detected via Western blotting. Subsequently, the regulatory mechanism of lncRNA ROR on Notch1 was analyzed using Luciferase reporter gene assay. Moreover, the changes in cell proliferation and apoptosis were determined through cell counting kit-8 (CCK-8) assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, respectively. Both lncRNA ROR and Notch1 were highly expressed in EC tissues (p<0.05). After overexpression of lncRNA ROR, HEC-1A cells had significantly enhanced proliferation (p<0.05) and weakened apoptosis (p<0.05). Meanwhile, the mRNA and protein levels of Notch1 rose remarkably compared with those in control group (p<0.05). Luciferase reporter gene assay revealed that lncRNA ROR could bind to the Notch1 regulatory factor miR-34a and inhibit its activity. LncRNA ROR regulates the proliferation and apoptosis of EC cells via promoting the expression of Notch1 protein.

MicorRNA-148b inhibits cell proliferation and facilitates cell apoptosis by regulating DNA Methyltransferase 1 in endometrial cancer.

BackgroundMicroRNA (miR)-148b has been shown to be dysregulated in a number of cancers; however, studies on the role of miR-148b in the gynaecologic malignancy endometrial cancer (EC) are rare. The purpose of this study was to explore the role of miR-148b in EC and the underlying molecular mechanism.MethodsThe expression levels of miR-148b and DNA methyltransferase 1 (DNMT1) were determined by quantitative real-time PCR (qRT-PCR) in both EC tissues and cell lines (HEC-1A and HEC-1B). These EC cell lines were then transfected with either an miR-148b inhibitor or miR-148b mimics, and cell proliferation, colony, and apoptosis and the cell cycle were measured by the cell counting kit-8, colony formation assay, and flow cytometry assays, respectively. In addition, the expression levels of p16, cyclin-dependent kinase 4 (CDK4), cyclin D1, caspase-3, B-cell lymphoma 2 (Bcl-2), and Bcl-2-associated X (Bax) were assessed by western blotting. Dual luciferase reporter and RNA pull-down assays were performed to investigate the target genes of miR-148b and validate their relationship.ResultsmiR-148b expression was down-regulated in both EC tissues and HEC-1A and HEC-1B cells, whereas DNMT1 was highly expressed. Moreover, transfection of miR-148b mimics inhibited cell proliferation and cell cycle progression, but induced cell apoptosis. Western blotting showed that transfection of miR-148b mimics markedly increased caspase-3 and cyclin D1 expression, whereas transfection of miR-148b inhibitor dramatically decreased the expression of caspase-3 and cyclin D1. Importantly, we determined that DNMT1 is a target gene of miR-148b in EC cells, and silencing of DNMT1 reversed the effects of miR-148b inhibitor on cell proliferation, cell cycle progression, and apoptosis in EC.ConclusionsmiR-148b inhibits cell proliferation and facilitates cell apoptosis in EC by regulating DNMT1.

IL-24 inhibits endometrial cancer cell proliferation by promoting apoptosis through the mitochondrial intrinsic signaling pathway

BackgroundEndometrial cancer is a type of malignant tumor of the female reproductive system. Preserving fertility in endometrial cancer patients is currently a formidable challenge. Interleukin-24 (IL-24) is a unique cytokine tumor suppressor gene belonging to the IL-10 cytokine family. IL-24 has broad-spectrum antitumor activity through different signaling pathways but does not affect normal cells. IL-24 gene therapy may provide a new method for the treatment of endometrial cancer. MethodsTransfection was used for gene transfer. The expression of IL-24 and related pathway proteins in endometrial cancer tissue and the Ishikawa cell line was detected by immunohistochemistry and Western blotting, respectively. The antitumor function of IL-24 was examined in vitro and in vivo. Cell proliferation was determined by CCK-8 assay, cell migration was shown by wound-healing assay, and cell invasion was detected by Transwell assay. Apoptosis was analyzed by TUNEL assay, and HE staining was performed to observe the morphology of the samples. ResultsImmunohistochemical analysis showed different expression levels of IL-24 in human endometrial cancer tissues and normal endometrial tissues. IL-24 increased protein expression of BAX and Cytochrome C, while BCL-2, MMP-3, VEGF, Caspase-9 and Caspase-3 expression was decreased. Overexpression of IL-24 inhibited cell proliferation, migration and invasion, but increased cell apoptosis in endometrial cancer. Mechanistically, we demonstrated that IL-24 inhibited endometrial cancer cell growth by inducing cell apoptosis through the mitochondrial intrinsic signaling pathway. In addition, IL-24 inhibited tumor development by inducing cell apoptosis and inhibiting angiogenesis, as shown in xenograft tumor experiments. ConclusionsOur study demonstrates the antitumor effect of IL-24 on endometrial cancer and shows that IL-24 may be a promising therapeutic gene for endometrial cancer gene therapy.

MicroRNA-183 induces epithelial-mesenchymal transition and promotes endometrial cancer cell migration and invasion in by targeting CPEB1.

The aim of this study is to evaluate the ability of microRNA-183 (miR-183) to influence epithelial-mesenchymal transition (EMT) and cell proliferation, migration, invasion, and apoptosis in endometrial cancer (EC) by targeting cytoplasmic polyadenylation element binding protein 1(CPEB1). EC tissues with matched nonmalignant tissues were collected from 208 EC patients. Ishikawa and RL95-2 cells were selected for cell experiments in vitro and each kind of cells were grouped into blank, negative control (NC), miR-183 mimic, miR-183 inhibitor, CPEB1 overexpression, and miR-183 mimic + CPEB1 overexpression groups. Expressions of miR-183, CPEB1, E-cadherin, and Vimentin were determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting. Cell viability, colony formation ability, migration, invasion, and apoptosis were assessed by MTT assay, clone formation assay, scratch test, Transwell assay, and flow cytometry. In vivo tumorigenesis of Ishikawa cells was evaluated by tumor formation in nude mice. The miR-183 expression was higher, but the CPEB1 expression was lower in EC tissues than in adjacent nonmalignant tissues. CPEB1 was confirmed as the target of miR-183 by dual-luciferase reporter assay. The miR-183 mimic group had increased cell viability, colony formation ability, cell invasion and migration, tumor volume and weight in nude mice, but decreased cell apoptosis when compared with the blank group. The expression of E-cadherin was down-regulate, but expression of Vimentin was up-regulate in the miR-183 mimic group in comparison with the blank group. In terms of a comparison between the blank group and CPEB1 overexpression group, the CPEB1 overexpression group had suppressed cell viability, colony formation ability, cell invasion and migration, tumor volume and weight, but increased cell apoptosis. The expression of E-cadherin was up-regulated, but the expression of Vimentin was down-regulated in the CPEB1 overexpression group in comparison with the blank group. The miR-183 mimic + CPEB1 overexpression group had higher miR-183 expression than the blank group. These findings indicate that miR-183 induces EMT, inhibits apoptosis, and promotes cell proliferation, migration, invasion, and in vivo tumorigenesis in EC by targeting CPEB1.

Foretinib (GSK1363089) induces p53-dependent apoptosis in endometrial cancer.

ObjectiveForetinib (GSK1363089 or XL880), which is an oral multikinase inhibitor developed to primarily target the hepatocyte growth factor (HGF)/Met signaling pathway, has shown anti-tumor effects against some cancers in preclinical and clinical studies.ResultsHGF/Met signaling in endometrial cancer cell lines was stimulated in an autocrine manner, and was essential for cell survival. Inhibiting the HGF/Met signaling with foretinib induced p53-dependent apoptosis in endometrial cancer cell lines in vitro. Foretinib also showed significant anti-cancer effects in vivo in experiments using cell tumor xenografts. p53 mutations were observed in 37 (10.8%) of 344 endometrial cancer specimens.ConclusionThe HGF/Met-MAPK/PI3K pathway in endometrial cancer is activated by HGF in an autocrine manner. Foretinib induces an anti-cancer effect through the anti-phosphorylation of Met, which results in the induction of p53-dependent apoptosis; foretinib was found to exert greater anti-cancer activity in endometrial cancer specimens with wild-type p53 than in specimens with p53 mutations. Our immunochemical analysis revealed that foretinib-induced p53-dependent apoptosis can be expected to have therapeutic potential in approximately 90% of endometrial cancer patients.MethodsWe evaluated the HGF/Met signaling pathway in endometrial cancer cell lines and assessed the anti-cancer effects of foretinib using in vitro and in vivo experimental models. Furthermore, endometrial cancer specimens were subjected to an immunohistochemical analysis.

SUMO-1 Promotes Ishikawa Cell Proliferation and Apoptosis in Endometrial Cancer by Increasing Sumoylation of Histone H4.

To investigate the functional role of SUMO-1 on cell proliferation and apoptosis in endometrial cancer cells (Ishikawa line) and to explore the underlying regulatory mechanisms. Different concentrations of estradiol (E2) and small interfering RNA (siRNA) targeting the SUMO-1 (siCo) were treated in Ishikawa cells, and then quantitative polymerase chain reaction was used to examine the expression of progesterone receptor (PR) expression in Ishikawa cells. Western blots were applied to validate histone H4 sumoylation. CCK8 assay and flow cytometry were performed to investigate cell proliferation and apoptosis in Ishikawa cells. Estradiol up-regulated the expression of PR messenger RNA, most obviously at 100 nM. SUMO-1 siRNA decreased the PR expression. Estradiol up-regulated H4 sumoylation and caused the increase of Ishikawa cell proliferation, whereas SUMO-1 siRNA down-regulated H4 sumoylation, inhibited the cell proliferation, and induced apoptosis. Furthermore, SUMO-1 siRNA-transfected cells were arrested in the S and G2/M phases and E2 increased the S and G2/M phases of Ishikawa cells. SUMO-1 regulates the Ishikawa cell proliferation and apoptosis by the sumoylation of histone H4.

Induction of Apoptosis in Endometrial Cancer (Ishikawa) Cells by Pogostemon cablin Aqueous Extract (PCAE).

Pogostemon cablin (PC) is a traditional herbal medicine used in the treatment of the common cold, nausea, diarrhea, and even for headaches and fever. However, the mechanisms underlying the anti-proliferative activity of PC in endometrial cancer (EC) cells have yet to be fully elucidated. This study investigated the anticancer effects of an aqueous extract of Pogostemon cablin (PCAE), specifically induced apoptosis in EC (Ishikawa) cells. Proliferation of EC cells following exposure to PCAE was assessed by an MTT assay. DNA content and the induction of cell cycle apoptosis were analyzed by flow cytometry (FACS Calibur). Protein caspase-3 and, -9 as well as AIF were investigated using Western blot. Our results demonstrate growth inhibition of Ishikawa cells by PCAE. Furthermore, caspase-3 activity caused PCAE-treated cell lines to accumulate in apoptosis. Gene expression profiling (GEP) results further suggest that, in addition to its known effects with regard to EC prevention, PCAE may also exert antitumor activity on established EC cells. Many previous studies have identified the chemo-preventive effects of natural plant materials and the potential role of these materials in chemotherapy. This current study used human EC Ishikawa cells to investigate the anti-tumor effects of PCAE in EC cells. Our results demonstrate that PCAE inhibits the growth of cancer cells and induces apoptosis, which suggests the potential applicability of PCAE as an antitumor agent.

Expression and the clinical significance of Wnt10a and Wnt10b in endometrial cancer are associated with the Wnt/β-catenin pathway

To determine the role played by the Wnt/β-catenin signaling pathway in the development of endometrial cancer (EC), we examined the expression of Wnt10a and Wnt10b in EC tissues and the correlation between their expression. Furthermore, the associations between these two proteins and the clinicopathological characteristics and prognosis of EC were also evaluated. In our search of alternative mechanisms, we investigated the impact of Wnt10b on proliferation and apoptosis of EC cells. Western blotting, 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were used to evaluate the expression of Wnt10b and some key proteins of the Wnt/β-catenin pathway, proliferation and apoptosis in EC. Our results showed that Wnt10b expression in EC tissues was significantly higher compared to that in hyperplastic and normal samples. The expression of Wnt10a in endometrioid cancer tissues was higher compared to that in other types of cancerous samples. The difference in Wnt10b levels was significant among subgroups for histological type, grade of differentiation, FIGO phase and lymphovascular metastasis. Furthermore, no correlation was observed between the expression of Wnt10a and Wnt10b. In the follow-up, Wnt10b gene expression was frequently upregulated in EC and associated with better prognostic clinicopathological markers in EC patients. Collectively, the in vitro data showed that the upregulated expression of Wnt10b in Ishikawa cells promoted proliferation and inhibited apoptosis through β-catenin and c-myc activation and adenomatous polyposis coli (APC) inhibition, which suggests that Wnt10b activates EC via the Wnt/β-catenin pathway. These results suggest that Wnt10b likely plays an important role in the development of EC. Furthermore, these results identify a role for Wnt10b in EC cells through promoting proliferation and inhibiting apoptosis, primarily through the activation of the Wnt/β-catenin pathway. The role played by Wnt10a in EC, however, still requires further investigation.

Abstract 1196: Progesterone via the PRB receptor attenuates AKT inhibitor mediated apoptosis in endometrioid endometrial cancer

Abstract Mutations in the PTEN gene are the most common genetic defects in endometrioid endometrial carcinoma and seen in more than 50% of tumors. PTEN, a tumor suppressor gene, negatively regulates PI3K/Akt-driven cell growth and survival. Previously, we have shown that levels of the forkhead protein, FOX01, a direct target of AKT, were significantly lower in endometrial carcinoma and overexpression of this gene in endometrial cancer cell lines resulted in decreased cell proliferation and increased apoptosis. Interestingly, the function of FOX01 in this context was determined by the progesterone receptor isoform that was expressed, strongly implicating the regulatory role of the progesterone receptor predictably at the transcription level. In this study, we aimed to look at the effects of an AKT inhibitor (APi59) on endometrial cancer cells and the influence of PRA or PRB on its efficacy. The cell viability assay revealed a decrease in the number of viable PRA and PRB cells treated with APi59 for 48 hours, while the progestin, R5020, alone did not affect cell viability. In addition, more cell death was observed in the PRA cells compared to the PRB cells. APi59 treatment promoted apoptosis, as measured by cleaved PARP levels, in both PRA and PRB cells, with increased apoptosis in PRA cells compared to the PRB cells. R5020 treatment alone did not cause apoptosis as compared to control. In order to further investigate the increased levels of apoptosis in the PRA cells, a real time PCR array focused on genes associated with apoptosis was used to identify potential genes involved in this differential response. The most highly upregulated gene specifically expressed in PRB cells in response to R5020 was BIRC3 (ciap2). BIRC3 was upregulated 13-fold with R5020 treatment in PRB cells where its expression in PRA cells was unaffected. Given that BIRC3 is a member of the inhibitor of apoptosis genes (IAP), we hypothesized that the increased expression of BIRC3 in PRB cells attenuated APi59-mediated apoptosis. Thus, PR was silenced using transient transfection of siRNA specific to PR and cells were treated with APi59 and R5020. Upon PR silencing, there was an increase in apoptosis as measured by cleaved PARP in APi59 treated cells along with a concomitant decrease in BIRC3 protein. To determine if the attenuation in apoptosis through BIRC3 occurred with other cytotoxic agents, PRB cells were treated with 10nm paclitaxel and R5020. Again, apoptosis in response to paclitaxel was attenuated, as shown by lower cleaved PARP levels when R5020 was added. In conclusion, not only can the AKT inhibitor, APi59, promote apoptosis in endometrial cancer cells, but liganded PRB can blunt the apoptotic response through increased expression of BIRC3, an inhibitor of apoptosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1196.