Endometrial Cancer Cell Migration Research Articles

∆9-tetrahydrocannabinol inhibits epithelial-mesenchymal transition and metastasis by targeting matrix metalloproteinase-9 in endometrial cancer.

Limited therapeutic interventions are clinically available for treating aggressive endometrial cancer (EC). Therefore, effective therapies are urgently required. Therefore, the present study investigated the role of ∆9-tetrahydrocannabinol (THC), which is reported to impact proliferative and migratory activities during impairment of cancer progression. In the present study, cell migration in response to THC was measured using transwell assays. Using western blot analysis, the levels of cannabinoid receptors in EC tissues were detected and pathways leading to the inhibition of cell migration by THC on human EC cells were determined. Results suggested that cannabinoid receptors were highly expressed in EC tissues. Furthermore, THC inhibited EC cell viability and motility by inhibiting epithelial-mesenchymal transition (EMT) and downregulating matrix metalloproteinase-9 (MMP-9) gene expression in aggressive human EC cells. The results have the potential to promote the development of novel compounds for the treatment of EC metastasis. The presnet findings suggest that THC may inhibit human EC cell migration through regulating EMT and MMP-9 pathways.

Cancer-associated fibroblasts induce epithelial-mesenchymal transition through secreted cytokines in endometrial cancer cells.

Endometrial cancer (EC) is the most common malignant gynecological disease. Cancer-associated fibroblasts (CAFs) serve an important role in the development and progression of EC through epithelial-mesenchymal transition (EMT). The aim of the present study was to examine the association between CAFs and EMT, and the possible mechanisms of action. Firstly, the CAFs and normal fibroblasts (NFs) were isolated and cultured, then an immunofluorescence assay was performed to analyze the purity and level of activation of CAFs and NFs, and then the conditional medium (CM) of CAFs and NFs was prepared. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting examined the expression levels of epithelial (E)-cadherin, neural (N)-cadherin and vimentin. A Matrigel® invasion assay and wound healing assay were used to analyze the effect of the CM on invasion and migration. An ELISA assay also measured the levels of various cytokines in the CM. In addition, EMT-associated proteins in metastatic lung tissues were detected by immunohistochemical assay. The results indicated that the CM of CAFs may decrease the level of E-cadherin, and increase the levels of N-cadherin and vimentin, while increasing the levels of invasion and metastasis in EC cells. The concentration of epidermal growth factor, transforming growth factor-β, hepatic growth factor and fibroblast growth factor in the CM of CAFs increased significantly, in comparison with the NFs group (P<0.05). The exogenous growth factors induced migration and invasion of EC cells. CAFs induced lung metastasis and the EMT process in vivo. These data suggested that cancer-associated fibroblasts may induce EMT through the secreted cytokines in endometrial cancer cells.

SOX15 regulates proliferation and migration of endometrial cancer cells.

The study aimed to investigate the effects of Sry-like high mobility group box 15 (SOX15) on proliferation and migration of endometrial cancer (EC) cells. Immunohistochemistry (IHC) was applied to determine the expression of SOX15 in EC tissues and adjacent tissues. We used cell transfection method to construct the HEC-1-A and Ishikawa cell lines with stable overexpression and low expression SOX15. Reverse-transcription quantitative real-time PCR (RT-qPCR) and Western blot were performed to examine expression of SOX15 mRNA and SOX15 protein, respectively. By conducting a series of cell proliferation assay and migration assay, we analyzed the influence of SOX15 overexpression or low expression on EC cell proliferation and migration. The expression of SOX15 mRNA and protein in EC tissues was significantly lower than that in adjacent tissues. After lentivirus-transfecting SOX15, the expression level of SOX15 mRNA and protein was significantly increased in cells of SOX15 group, and decreased in sh-SOX15 group. Overexpression of SOX15 could suppress cell proliferation, while down-regulation of SOX15 increased cell proliferation. Flow cytometry results indicated that overexpression of SOX15 induced the ratio of cell-cycle arrest in G1 stage. In addition, Transwell migration assay results showed that SOX15 overexpression significantly inhibited cell migration, and also down-regulation of SOX15 promoted the migration. As a whole, SOX15 could regulate the proliferation and migration of EC cells and up- regulation of SOX15 could be valuable for EC treatment.

MiR-143 inhibits endometrial cancer cell proliferation and metastasis by targeting MAPK1.

Endometrial cancer (EC) is one of the most commonly diagnosed gynecologic malignancies in the world, with the morbidity rate of over 7%. The mechanism of the pathogenesis has not been specifically elucidated to date, which is imperative for EC treatment. The aim of our study was to investigate the target relationship between miR-143 and mitogen-activated protein kinase 1 (MAPK1) and explore the effect of miR-143 on the endometrial cancers (EC) cells through targeting MAPK1. We collected EC tissues and adjacent tissues, and transfected miR-143 mimics and MAPK1 siRNA into EC cells with lipofectamine. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot were used to examine the expression of miR-143 and MAPK1 mRNA and the protein expression of MAPK1. Cell counting kit-8, wound healing assay, flow cytometry and transwell assay were applied to examining the alteration of the proliferation, migration, cell cycle and invasion ability of EC cells. We predicted the targeting gene of miR-143 through bioinformatics analysis. MiR-143 was found under-expressed in EC tissues and cells. Overexpression of miR-143 or knockdown of MAPK1 in human EC cell line HEC-1B inhibited the EC cell proliferation, migration and invasion and induced apoptosis. MAPK1 was verified to be a target gene of miR-143. MiR-143 overexpression could effectively inhibit mRNA and protein expression of MAPK1 in HEC-1B cells. Collectively, miR-143 might inhibit the proliferation, migration and invasion of EC cells, and promote the apoptosis of EC cells by suppressing MAPK1. These findings provided a view for new and potential therapeutic method for the clinical treatment of EC.

Curcumin exhibits anti-tumor effect and attenuates cellular migration via Slit-2 mediated down-regulation of SDF-1 and CXCR4 in endometrial adenocarcinoma cells

Although curcumin shows anti-proliferative and anti-inflammatory activities in various cancers, the effect of curcumin on cellular migration in endometrial adenocarcinoma cells remains to be understood. The current investigation was aimed to explore the anti-proliferative and anti-migratory effects of curcumin and its mechanism of action in endometrial cancer cells. Our in-vitro and in-vivo experimental studies showed that curcumin inhibited the proliferation of endometrial cancer cells and suppressed the tumor growth in Ishikawa xenograft mouse model. Curcumin induced ROS-mediated apoptosis in endometrial cancer cells. Curcumin suppressed the migration rate of Ishikawa and Hec-1B cells as analyzed by scratch wound assay. In transwell migration studies, knock down of Slit-2 reversed the anti-migratory effect of curcumin in these cell lines. Curcumin significantly up-regulated the expression of Slit-2 in Ishikawa, Hec-1B and primary endometrial cancer cells while it down-regulated the expression of stromal cell-derived factor-1 (SDF-1) and CXCR4 which in turn, suppressed the expression of matrix metallopeptidases (MMP) 2 and 9, thus attenuating the migration of endometrial cancer cells. In summary, we have demonstrated that curcumin has inhibitory effect on cellular migration via Slit-2 mediated down-regulation of CXCR4, SDF-1, and MMP2/MMP9 in endometrial carcinoma cells. These findings helped explore the role of Slit-2 in endometrial cancer cells.

Urocortin suppresses endometrial cancer cell migration via CRFR2 and its system components are differentially modulated by estrogen

Urocortin (UCN1) peptide shares structural and functional homology with corticotropin‐releasing factor (CRF). UCN1 is significantly reduced in endometrial adenocarcinoma compared to healthy controls. However, there are no data which evaluate the effects of UCN1 in the endometrium, or how it is modulated. We used proliferation and transwell assays to determine the effect of UCN1 on the proliferation and migration of Ishikawa and HEC1A cells. We also determined the expression levels of UCN1 and its receptors produced by estrogen receptor agonists, and the effect of UCN1 on estrogen receptor expression, using quantitative polymerase chain reaction. UCN1 suppressed migration of endometrial cancer cells in vitro. This effect appears to be specific to CRF receptor 2 (CRFR2), as selective antagonism of CRFR2 but not CRFR1 completely eliminated suppression of migration. Activation of ERA reduced UCN1 expression, but only had a small effect on the expression of CRFR1. However, expression of CRFR2 was more notably reduced at both the mRNA and protein levels by activation of ERB. UCN1 in turn reduced both ERA and ERB expression, as assessed by real‐time quantitative PCR. We demonstrate that UCN1 significantly suppresses the migration of endometrial cancer cells but has no effect on their proliferation. Thus, loss of UCN1 in endometrial cancer may promote invasion and metastatic spread. There is a complex relationship between the UCN1 system and estrogen receptors, which may provide insights into endometrial carcinogenesis, a disease known to be driven by estrogen excess.

MicroRNA-93 Promotes Epithelial-Mesenchymal Transition of Endometrial Carcinoma Cells.

MicroRNA-93, derived from a paralog (miR-106b-25) of the miR-17-92 cluster, is involved in the tumorigenesis and progression of many cancers such as breast, colorectal, hepatocellular, lung, ovarian, and pancreatic cancer. However, the role of miR-93 in endometrial carcinoma and the potential molecular mechanisms involved remain unknown. Our results showed that miR-93 was overexpressed in endometrial carcinoma tissues than normal endometrial tissues. The endometrial carcinoma cell lines HEC-1B and Ishikawa were transfected with miR-93-5P, after which cell migration and invasion ability and the expression of relevant molecules were detected. MiR-93 overexpression promoted cell migration and invasion, and downregulated E-cadherin expression while increasing N-cadherin expression. Dual-luciferase reporter assay showed that miR-93 may directly bind to the 3′ untranslated region of forkhead box A1 (FOXA1); furthermore, miR-93 overexpression downregulated FOXA1 expression while miR-93 inhibitor transfection upregulated FOXA1 expression at both mRNA and protein level. In addition, transfection with the most effective FOXA1 small interfering RNA promoted both endometrial cancer cell migration and invasion, and downregulated E-cadherin expression while upregulating N-cadherin expression. Therefore, we suggest that miR-93 may promote the process of epithelial–mesenchymal transition in endometrial carcinoma cells by targeting FOXA1.

Perfluorooctanoic acid induces human Ishikawa endometrial cancer cell migration and invasion through activation of ERK/mTOR signaling.

Perfluorooctanoic acid (PFOA) is a common environmental pollutant that has been associated with various diseases, including cancer. We explored the molecular mechanisms underlying PFOA-induced endometrial cancer cell invasion and migration. PFOA treatment enhanced migration and invasion by human Ishikawa endometrial cancer cells, which correlated with decreased E-cadherin expression, a marker of epithelial-mesenchymal transition. PFOA also induced activation of ERK1/2/mTOR signaling. Treatment with rapamycin, an mTOR inhibitor, antagonized the effects of PFOA and reversed the effects of PFOA activation in a xenograft mouse model of endometrial cancer. Consistent with these results, pre-treatment with rapamycin abolished PFOA-induced down-regulation of E-cadherin expression. These results indicate that PFOA is a carcinogen that promotes endometrial cancer cell migration and invasion through activation of ERK/mTOR signaling.

TGF-β1 stimulates migration of type II endometrial cancer cells by down-regulating PTEN via activation of SMAD and ERK1/2 signaling pathways

PTEN acts as a tumor suppressor primarily by antagonizing the PI3K/AKT signaling pathway. PTEN is frequently mutated in human cancers; however, in type II endometrial cancers its mutation rate is very low. Overexpression of TGF-β1 and its receptors has been reported to correlate with metastasis of human cancers and reduced survival rates. Although TGF-β1 has been shown to regulate PTEN expression through various mechanisms, it is not yet known if the same is true in type II endometrial cancer. In the present study, we show that treatment with TGF-β1 stimulates the migration of two type II endometrial cancer cell lines, KLE and HEC-50. In addition, TGF-β1 treatment down-regulates both mRNA and protein levels of PTEN. Overexpression of PTEN or inhibition of PI3K abolishes TGF-β1-stimulated cell migration. TGF-β1 induces SMAD2/3 phosphorylation and knockdown of common SMAD4 inhibits the suppressive effects of TGF-β1 on PTEN mRNA and protein. Interestingly, TGF-β1 induces ERK1/2 phosphorylation and pre-treatment with a MEK inhibitor attenuates the suppression of PTEN protein, but not mRNA, by TGF-β1. This study provides important insights into the molecular mechanisms mediating TGF-β1-induced down-regulation of PTEN and demonstrates an important role of PTEN in the regulation of type II endometrial cancer cell migration.

Mifepristone inhibites the migration of endometrial cancer cells through regulating H19 methylation

To investigate the effect and mechanism of mifepristone on the migration of human endometrial carcinoma cells. A human endometrial carcinoma cell line, Ishikawa cells, was cultured in vitro and treated with mifepristone at different concentrations. Wound healing assay was applied to detect the migration of Ishikawa cells. RT-PCR and methylation-specific PCR (MSP) were used to detect the levels of H19 mRNA and its DNA methylation. Western-blot was used to detect the expressions of HMGA2 and epithelial to mesenchymal transition (EMT) related proteins. When treated with different concentrations of mifepristone for 48 hours, the width of scratch of the the control group, the 5 mg/L and the 10 mg/L mifepristone treatment groups were (4.18±0.07)mm, (4.68±0.07)mm, and(4.99±0.07)mm, respectively (P<0.05 for all) and treated with mifepristone for 72 hours, those were(3.46±0.07)mm, (4.29±0.07)mm, and(4.78±0.04)mm, respectively (P<0.05 for all). In the Ishikawa cells, mifepristone suppressed the transcriptional level of H19 through enhancing its promoter methylation, which resulted in inhibited expressions of HMGA2 and vimentin and increased expression of E-cadherin in a time- and concentration-dependent manner. Mifepristone inhibits the migration of endometrial carcinoma cells partially through methylation-induced of transcriptional inhibition of H19, which results in the down-regulation of HMGA2 and vimentin and upregulation of E-cadherin.

Promotion of epithelial-mesenchymal transition by Frizzled2 is involved in the metastasis of endometrial cancer

The Wnt signaling pathway is essential for embryonic development, and genetic alteration in this network is closely correlated with tumorigenesis and progression. Previous research has shown that Wnt receptor Frizzled2(Fzd2) is elevated in many metastatic cancer cell lines and high grade tumors. Yet, little is known about the Fzd2 expression and activity in human endometrial cancer(EC). In this study, we present evidence of a direct role of Fzd2 in human EC. We found that Fzd2 expression was higher in EC than that in adjacent normal tissues, and was correlated with epithelial‑mesenchymal transition markers. Next, it was determined that the stable overexpression of Fzd2 in HEC-1B and Ishikawa cells promoted cell migration and induced an EMT phenotype. Conversely, RNA interference-mediated depletion of Fzd2 inhibited EC cell migration. Additionally, mechanistic investigation revealed that elevated Fzd2 expression activated canonical Wnt signaling and was blocked by canonical Wnt signaling inhibitor XAV939. However, Fzd2 did not influence the proliferation of EC cells. Thus, Fzd2 may be a potential marker for EC metastasis and a target for future therapies for this disease.

HMGA1 facilitates tumor progression through regulating Wnt/β-catenin pathway in endometrial cancer.

Recent studies have identified a unique role for high mobility group protein A1 (HMGA1) as a major regulator of tumor progression and in diverse tumor models. Emerging evidences indicate that overexpressed HMGA1 facilitates multiple malignant phenotypes of cancer cells, however, the oncogenic activities of HMGA1 in endometrial cancer (EC) remains elusive. Here we showed that HMGA1 was more frequently expressed in human EC tissues compared to non-tumor tissues. Elevated HMGA1 was significantly associated with advanced clinical stage. Wound-healing assay and transwell assay showed that HMGA1 can positively regulate cell migration and invasion. Mechanistically, luciferase reporter assay and Western blotting assay demonstrated that activation of Wnt/β-catenin pathway contributed to the oncogenic activity of HMGA1. Taken together, our data reveal that HMGA1 may function as an oncogene and modulate EC cell migration and invasion by activating Wnt/β-catenin pathway, implying that suppression of HMGA1 might be a potential therapeutic strategy for EC.

Activin B promotes endometrial cancer cell migration by down-regulating E-cadherin via SMAD-independent MEK-ERK1/2-SNAIL signaling

High-risk type II endometrial cancers account for ~30% of cases but ~75% of deaths due, in part, to their tendency to metastasize. Histopathological studies of type II endometrial cancers (non-endometrioid, mostly serous) suggest overproduction of activin B and down-regulation of E-cadherin, both of which are associated with reduced survival. Our previous studies have shown that activin B increases the migration of type II endometrial cancer cell lines. However, little is known about the relationship between activin B signaling and E-cadherin in endometrial cancer. We now demonstrate that activin B treatment significantly decreases E-cadherin expression in both a time- and concentration-dependent manner in KLE and HEC-50 cell lines. Interestingly, these effects were not inhibited by knockdown of SMAD2, SMAD3 or SMAD4. Rather, the suppressive effects of activin B on E-cadherin were mediated by MEK-ERK1/2-induced production of the transcription factor SNAIL. Importantly, activin B-induced cell migration was inhibited by forced-expression of E-cadherin or pre-treatment with the activin/TGF-β type I receptor inhibitor SB431542 or the MEK inhibitor U0126. We have identified a novel SMAD-independent pathway linking enhanced activin B signaling to reduced E-cadherin expression and increased migration in type II endometrial cancer.

S100A4 promotes endometrial cancer progress through epithelial-mesenchymal transition regulation.

Epithelial-mesenchymal transition (EMT) is a major cause of endometrial cancer (EC) to initiate invasion and metastasis. S100A4, a calcium-binding protein, is implicated in multistage of tumorigenesis and tumor progression. The correlation between S100A4 and EMT in EC is still unclear. This study was aimed to clarify the role of S100A4 in EC and the relationship between S100A4 expression and EMT markers. S100A4, E-cadherin, and vimentin were detected in tissues of EC patients (n=50) by immunohistochemistry. The impact of S100A4 on EC cell proliferation, migration and invasion was investigated via RNA interference, and the correlation between S100A4 and EMT markers were also explored. The results showed that S100A4 was significantly increased in epithelial cells of EC compared with the normal endometrium (P<0.05), also S100A4 level was positively related to age (P=0.021), histological grade (P<0.001), and lymph node metastasis (P<0.001). Additionally, silencing of S100A4 remarkably attenuated EC cell migration and invasion. Significant morphological change accompanied with the downregulation of EMT markers, E-cadherin and vimentin were also observed. Aberrant S100A4 expression may predict EC progression and play an important role in regulating EC cell invasion through EMT regulation. Hence, S100A4 is a promising therapeutic target.

The role of glycogen synthase kinase-3β (GSK-3β) in endometrial carcinoma: A carcinogenesis, progression, prognosis, and target therapy marker.

PurposeGlycogen synthase kinase-3β (GSK-3β) is a serine/threonine kinase involved in cancer development. Herein, we demonstrated the role of GSK-3β in endometrial cancer (EC) and identified new therapeutic targets.ResultsGSK-3β was overexpressed in EC tissues, and was positively correlated with International Federation of Gynecology and Obstetrics (FIGO) staging, dedifferentiation, and myometrial infiltration depth. Besides, GSK-3β overexpression predicted lower cumulative and relapse-free survival rate. si-GSK-3β transfection suppressed cell proliferation, migration, invasion, and promoted cell apoptosis through downregulating NF-kB, Cyclin D1 and MMP9 expression whereas upregulating P21 expression. Bioinformatic predictions and dual-luciferase reporter assays showed that GSK-3β was a possible target of miR-129. MiR-129 transfection reduced GSK-3β expression, and exhibited the same trend as si-GSK-3β transfection in cell function experiments. The nude mouse xenograft assay showed that miR-129 overexpression may suppress tumor growth through downregulating GSK-3β expression. Further studies showed that AZD1080, a GSK-3β inhibitor, could also inhibit EC cell proliferation, migration and invasion, while induced cell apoptosis through modulating relevant genes downstream of GSK-3β signaling.Experimental DesignGSK-3β expression was determined in EC tissue and normal endometrial tissues by immunohistochemistry. After GSK-3β down-regulation by si-GSK-3β, microRNA-129 mimic transfection or GSK-3β inhibitor exposure, EC cell phenotypes and related molecules were examined.ConclusionsOur results demonstrate for the first time that GSK-3β may be a novel and important therapeutic target for the treatment of endometrial carcinoma. GSK-3β inhibitor AZD1080 may be an effective drug for treating endometrial carcinoma.

Reactivation of epigenetically silenced miR-124 reverses the epithelial-to-mesenchymal transition and inhibits invasion in endometrial cancer cells via the direct repression of IQGAP1 expression.

Overexpression of IQGAP1 and microRNA (miRNA) dysregulation are frequent in human tumors, but little is known about the role of IQGAP1 and its relationship to miRNA in endometrial carcinogenesis. We demonstrate that IQGAP1 activates the epithelial–mesenchymal transition (EMT) program and that miR-124 directly represses IQGAP1 expression in endometrial cancer (EC) cells. The overexpression of IQGAP1 stimulates EMT features and enhances migration, invasion and proliferation of EC cells, whereas knocking down IQGAP1 expression reverses EMT and inhibits these malignant properties. Using miRNA microarray profiling, we identified 29 miRNAs (let-7b, let-7f, miR-10b, miR-15b, miR-23a, miR-24, miR-25, miR-27a, miR-29b, miR-30a-5p, miR-34a, miR-124, miR-127, miR-130b, miR-148a, miR-155, miR-191*, miR-194, miR-224, miR-362, miR-409-3p, miR-422b, miR-424, miR-453, miR-497, miR-518d, miR-518f*, miR-526a and miR-656) that are significantly down-regulated in an in vitro-selected highly invasive derivative cell line (HEC-50-HI) relative to the parental HEC-50 cells. We further identified miR-124 as a direct regulator of IQGAP1 in EC cells. Enforced expression of miR-124 suppresses EC cell invasion and proliferation. The expression of IQGAP1 mRNA was significantly elevated in EC tissues, while the expression of miR-124 was decreased. The downregulation of miR-124 correlates with a poor survival outcome for patients with EC. Treating EC cells with the demethylating agent 5-aza-2′-deoxycytidine increased miR-124 expression and down-regulated IQGAP1 levels. Our data suggest that IQGAP1 promotes EMT, migration and invasion of EC cells. MiR-124, a novel tumor suppressor miRNA that is epigenetically silenced in EC, can reverse EMT and the invasive properties, by attenuating the expression of the IQGAP1 oncogene.

MicroRNA-126 inhibits the migration and invasion of endometrial cancer cells by targeting insulin receptor substrate 1

MicroRNAs (miRs) have been demonstrated to serve important roles in the development and progression of human cancer, primarily through the direct targeting of oncogenes or tumor suppressors. It has been previously suggested that miR-126 may be associated with endometrial cancer (EC). However, the exact role of miR-126 in the migration and invasion of EC cells has not yet been studied. The present study demonstrated that the expression of miR-126 was significantly decreased in EC tissues when compared with matched normal adjacent tissues. The current study reverse transcription-quantitative polymerase chain reaction was performed in order to examine the expression level of miR-126. Wound healing and transwell assays were used to examine cell migration and invasion. A luciferase reporter assay was used to determine the targeting relationship and western blotting assay was performed to detect the protein expression. Furthermore, the overexpression of miR-126 significantly inhibited EC SKOV3 cell migration and invasion. Molecular mechanism investigation established that insulin receptor substrate 1 (IRS1) functioned as a direct miR-126 target, and its expression was negatively regulated by miR-126 at a post-transcriptional level in the SKOV3 cells. Additionally, the overexpression of IRS1 reversed the inhibitory effect of miR-126 overexpression on SKOV3 cell migration and invasion. In conclusion, the current study demonstrated that miR-126 inhibited EC cell migration and invasion, at least partially through the direct targeting of IRS1, suggesting that miR-126 may aid the treatment of EC metastasis.

Ca2+ channel subunit α 1D promotes proliferation and migration of endometrial cancer cells mediated by 17β-estradiol via the G protein-coupled estrogen receptor.

Calcium and calcium channels are closely related to the estrogen-induced nongenomic effect of endometrial carcinoma, but the specific role of calcium channels is unknown. This study aimed to explore the expression and the biologic effect of the L-type calcium channel in endometrial carcinoma cells and to clarify the molecular mechanism of the relationship between L-type calcium channels and estrogen. The immunohistochemical results showed that Ca(2+) channel subunit α 1D (Cav1.3) expression was high in atypical hyperplasia (1.90 ± 0.35) and endometrial carcinoma tissues (2.05 ± 0.82) but weak (0.80 ± 0.15) in benign endometrial tissues (P < 0.05). Treatment with 17β-estradiol rapidly increased Cav1.3 expression in a dose- and time-dependent manner, and 100 nM cell-impermeable β-estradiol-6-(O-carboxymethyl)oxime:bovine serum albumin also promoted Cav1.3 expression. Transfection with small interfering RNA against G protein-coupled estrogen receptor (GPER) suppressed estrogen-induced up-regulation of Cav1.3 compared with control cells and markedly reduced the estrogen-induced phosphorylation of ERK1/2 and CREB. Knocking down the Cav1.3 significantly suppressed estrogen-stimulated Ca(2+) influx, cell proliferation, and migration in endometrial cancer cells. Taken together, Cav1.3 was overexpressed in atypical hyperplasia and endometrial carcinoma, and the estrogen-induced phosphorylation of downstream molecular ERK1/2 and CREB is the result of activation of the GPER pathway. L-type channel Cav1.3 is required for estrogen-stimulated Ca(2+) influx and contributes broadly to the development of endometrial cancer. The Cav1.3 channel may be a new target for endometrial carcinoma treatment.

MPA influences tumor cell proliferation, migration, and invasion induced by RANKL through PRB involving the MAPK pathway in endometrial cancer.

The targeting of receptor activator of nuclear factor-κB ligand (RANKL) is being increasingly investigated as a potential therapeutic strategy in several types of cancers. However, the exact function and mechanism of RANKL in human endometrial cancer (EC), particularly in progesterone-resistant and aggressive EC, remain unclear. We evaluated whether targeting of RANKL might be an efficient therapeutic strategy in EC. In the present study, we performed the first investigation of the relationship between RANK/RANKL expression in EC tissues and clinicopathological features. In the present study, we showed that RANK/RANKL was aberrantly overexpressed in human EC tissues. The higher RANK expression in human EC was associated with myometrial invasion, lymph node metastasis and lymphovascular space involvement. Additionally, we discovered that RANK/RANKL promoted EC cell proliferation, migration and invasion, which was correlated with the activated mitogen-activated protein kinase (MAPK) pathway. Moreover, medroxyprogesterone acetate (MPA)-mediated progesterone receptor B (PRB) was found to significantly inhibit the EC cell behavior induced by RANKL in vitro. Furthermore, MPA efficiently inhibited the tumorigenicity in an in vivo xenograft model. Collectively, RANKL is a common tumor promoter, which activates MAPK signaling in EC cells. MPA-mediated PRB plays important roles in inhibiting the growth, migratory and invasive capacities of EC cells induced by RANKL. Targeting of RANKL may be useful in the treatment of EC.

Kisspeptin-10 Inhibits Stromal-Derived Factor 1–Induced Invasion of Human Endometrial Cancer Cells

The cross talk between metastatic cancer cells and target sites is critical for the development and progression of metastases. Disruption of this interaction will allow to design mechanism-based effective and specific therapeutic interventions for metastases. We have established a coculture system of cells derived from different tumor entities and MG63 human osteoblastlike cells to analyze tumor cell invasion. Recently, we have shown that breast cancer cell invasion was dramatically increased when cocultured with MG63 cells.Using this model, we have now analyzed whether stromal-derived factor 1 (SDF-1) is responsible for human endometrial cancer cell invasion and whether kisspeptin-10 (KP-10) treatment affects SDF-1-induced invasion of endometrial cancer cells in vitro. Invasion was quantified by assessment of endometrial cancer cell migration rate through an artificial basement membrane in a modified Boyden chamber during coculture with MG63 cells or after treatment with SDF-1α, SDF-1β, or the combination of both SDF-1 isoforms. In addition, the role of SDF-1 in invasion of endometrial cancer cells was analyzed by blocking SDF-1 secretion during coculture with MG64 cells. Furthermore, the effects of KP-10 treatment on MG63 coculture-driven and SDF-1-induced invasion were analyzed. Endometrial cancer cell invasion was significantly increased when cocultured with MG63 cells. Treatment with KP-10 reduced the ability to invade a reconstituted basement membrane and to migrate in response to the cellular stimulus. This effect was significant in a dose window of 10(-13) to 10(-11) mol/L. During coculture, SDF-1 protein expression of MG63 cells was significantly increased. The MG63 coculture-induced increase of endometrial cancer cell invasion could be blocked by anti-SDF-1 antibodies. Treatment of endometrial cancer cells in monoculture (without MG63) with SDF-1α, SDF-1β, or the combination of both isoforms resulted in a significant increase of endometrial cancer cell invasion. The SDF-1-induced increase of endometrial cancer cell invasion was significantly reduced after treatment with KP-10. Our findings suggest that SDF-1 plays a major role in endometrial cancer invasion. Stromal-derived factor 1-induced invasion can be inhibited by KP-10 treatment.