Apoptosis Of Eca109 Cells Research Articles

The inhibition effects of apatinib on cell proliferation, migration and apoptosis in esophageal carcinoma via Ras/Raf/MEK/ERK and JAK2/STAT3 pathways

Objective: To investigate the in vitro and in vivo effects of apatinib in esophageal squamous cell carcinoma and the underlying mechanisms. Methods: The esophageal cancer cells, KYSE-150 and ECA-109, were divided into control group and apatinib treatment group at the concentrations of 2.5, 5, 10, 20 and 40 μmol/L respectively. All of experiments were performed in triplicate. MTT and colony formation assays were used to measure cell proliferation. Transwell assay was used to determine the migration capacity. The effect of apatinib on cell cycle and apoptosis was analyzed by flow cytometry. The expression of VEGF and VEGFR-2 was measured by real-time quantitative PCR (qRT-PCR). The concentration of VEGF in the cell supernatant was assessed by enzyme-linked immunosorbent assay (ELISA). The expression levels of MEK, ERK, p-MEK, p-ERK, JAK2, STAT3 and p-STAT3 after VEGF stimulation were detected by Western blot. Furthermore, the nude mice xenograft model was established. The tumor-bearing mice were randomly divided into control group, apatinib low dose treatment group (250 mg) and apatinib high dose treatment group (500 mg), respectively. Tumor inhibition rates of different groups were calculated. And then the expressions of VEGF and VEGFR2 were detected in xenograft tissues by immunohistochemical staining. Results: In the presence of 20 μmol/L and 40 μmol/L of apatinib for 24 hours, the migration cell numbers of KYSE-150 and ECA-109 were 428.67±4.16 and 286.67±1.53 as well as 1 123.67±70.00 and 477.33±26.84, respectively, that were significantly lower than control group (P<0.05 for all). In addition, after treatment with 10 μmol/L, 20 μmol/L and 40 μmol/L of apatinib for 7 days on KYSE-150 and ECA-109, the colony formation rates were (65.12±25.48)%, (58.19±24.73)% and (29.10±22.40)% as well as (70.61±15.14)%, (61.12±17.21)% and (43.09±11.13)%, respectively. The colony formation rates of 20 μmol/L and 40 μmol/L of apatinib treatment groups were significantly lower than control group (100.00±0.00, P<0.05). The cell cycle ratio of G(2)/M phase and apoptosis rate of control group and 20 μmol/L apatinib group in KYSE-150 cells were (12.14±2.13)% and (3.49±0.74)% as well as (26.27±3.30)% and (15.65±1.54)%, respectively. The corresponding ratios in ECA-109 cells were (3.44±0.57)% and (6.31±1.43)% as well as (22.64±2.36)% and (49.26±1.62)%, respectively. The results show that apatinib suppressed cell cycle progression at G(2)/M phase and induced cell apoptosis in both KYSE-150 and ECA-109 cells (P<0.05 for all). In the presence of 20 μmol/L and 40 μmol/L of apatinib in KYSE-150 cells, the relative levels of VEGF mRNA were (42.57±10.43)% and (25.69±1.24)%, and those of VEGF-2 mRNA were (36.09±10.82)% and (13.99±6.54)%, which were all significantly decreased compared to control group (100.00±0.00, P<0.05 for all). For ECA-109 cells, the relative expression of VEGF and VEGFR2 showed similar tendency (P<0.05 for all). Moreover, after treatment with 20 μmol/L and 40 μmol/L of apatinib in KYSE-150 cells, the VEGF concentrations were (766.48±114.27) pg/ml and (497.40±102.18)pg/ml, which were significantly decreased compared to control group [(967.41±57.75) pg/ml, P<0.05)]. The results in ECA-109 were consistent (P<0.05). Furthermore, after treatment with 40 μmol/L of apatinib in KYSE-150 and ECA-109, the relative expression of p-MEK and p-ERK were 0.49±0.05 and 0.28±0.03 as well as 0.63±0.03 and 1.22±0.15, which were significantly lower than control group (1.23±0.19 and 0.66±0.07 as well as 1.03±0.20 and 1.76±0.20; P<0.05). The relative expression of STAT3, p-STAT3 in control group and experimental group were 0.96±0.15 and 0.85±0.16 as well as 0.62±0.09 and 0.36±0.13, respectively. The results showed that the protein levels of STAT3 and p-STAT3 were significantly lower than the control group (P<0.05 for all). The inhibition rates of apatinib in xenograft nude mice were 29.25% and 19.96% for 250 mg and 500 mg treatment groups. The concentration of VEGF were (25.11±4.12) pg/ml, (16.40±2.81) pg/ml and (15.04±4.88)pg/ml for control, 250 mg and 500 mg treatment groups, respectively. Conclusions: Apatinib can inhibit cell proliferation, induce apoptosis and suppress migration of esophageal cancer cells in vitro and in vivo. This effect was mainly mediated via the alterations of Ras/Raf/MEK/ERK pathway and JAK2/STAT3 pathway.

Time profile of nimotuzumab for enhancing radiosensitivity of the Eca109 cell line.

The aim of the present study was to investigate the ability of Nimotuzumab to increase radiosensitivity at different delivery times in the mixed cancer cell line Eca109, to determine the optimal delivery time. Cultured Eca109 cells were classified into five groups: Control with no treatment (O group); irradiation without Nimotuzumab treatment (R group); treatment with Nimotuzumab 24 h prior to or after irradiation (24NR or 24RN group, respectively); and Nimotuzumab combined with irradiation simultaneously (NR group). Following cells reaching the logarithmic-growth phase, cell survival after exposure to Nimotuzumab was evaluated using an MTT assay; thereafter, the 50% inhibitory concentration (IC50) of the cell line was calculated. Cell-survival curves were generated using a colony-forming assay. Flow cytometry analysis was used to detect apoptosis rates and cell-cycle distribution. The expression level of epidermal growth factor receptor was measured in Eca109 cells with western blotting. Growth inhibition was only observed 72 h after exposure to Nimotuzumab. The IC50 was 768 µg/ml. At a dose of 0.2 IC50 or 0.3 IC50, the sensitization enhancement ratio of radiosensitivity was highest in the 24NR group. Nimotuzumab enhanced radiation-induced apoptosis in Eca109 cells, with the optimal delivery time at 24 h prior to irradiation (P=0.035). The concentration of Nimotuzumab administered was directly proportional to the increase in radiosensitivity of the cells.

Grape Seed Proanthocyanidin Extract Inhibits Human Esophageal Squamous Cancerous Cell Line ECA109 via the NF-κB Signaling Pathway.

Esophageal squamous cell carcinoma is the most common type of squamous cell carcinoma. Grape seed proanthocyanidin extract (GSPE) is considered to exhibit anticancer activity against several different types of cancer. We aimed to determine whether GSPE inhibited esophageal squamous cancerous cells and the possible involvement of NF-κB in this process. The human esophageal squamous cancer cell line ECA109 was treated with GSPE (0–80 μg/mL) and BAY11-7082 (10 μmol/L) for 12, 24, and 48 h. The MTT assay was used to determine cell proliferation; alterations in cell apoptosis were detected by flow cytometry; levels of inflammatory factors interleukin-6 and cyclooxygenase-2 and apoptotic proteins Bax/Bcl-2 were measured by ELISA; qRT-PCR and western blots were used to examine the activation of caspase-3 and NF-κB signaling. GSPE inhibited the proliferation of ECA109 cells and induced cellular apoptosis in a time- and dose-dependent manner. ELISA results showed that GSPE and BAY11-7082 reduced the secretion of inflammatory cytokines interleukin-6 and cyclooxygenase-2. The results of PCR and western blotting indicated that GSPE and BAY11-7082 activated caspase-3 and attenuated the activation of the NF-κB signaling pathway. GSPE induced apoptosis in ECA109 cells and inhibited ECA109 cell proliferation via a reduction in the secretion of inflammatory cytokines. This mechanism may be related to the attenuation of NF-κB activity and the sensitization of caspase-3.

Protective effect of propofol on hydrogen peroxide-induced human esophageal carcinoma via blocking the Wnt/β-catenin signaling pathway.

Objective(s):To analyze the potential influences of propofol on the oxidative stress of H2O2-induced human esophageal squamous cell carcinoma (ESCC) Eca109 cell through mediating the Wnt/β-catenin signaling pathway.Materials and Methods:Eca109 cells were classified into 5 groups: Control group, H2O2 group, Propofol + H2O2 group, Dkk1 (Dickkopf-1, Wnt/β-catenin pathway antagonist) + H2O2 group, and Propofol + LiCl (Lithium chloride, Wnt/β-catenin pathway agonist) + H2O2 group. Western blotting was performed to determine the protein expressions, flow cytometry to measure the content of ROS, immunofluorescence staining to detect the oxidative DNA damage, as well as MTT, AnnexinV-FITC/PI, Wound-healing, and Transwell assays to test the biological characteristics of Eca109 cells.Results:H2O2 resulted in the increased nuclear and cytoplasmatic expression of β-catenin, reduced p-GSK3β expression, up-regulated ROS content, and induced oxidative DNA damage in Eca109 cells. Moreover, Eca109 cells treated with H2O2 alone had enhanced cell proliferation and metastasis but decreased cell apoptosis, as compared with those without any treatment; meanwhile, the declined Cyt C, Bax, and cleaved caspase-3, as well as the elevated Bcl-2 were also observed in Eca109 cells in the H2O2 group, which were reversed by Propofol or Dkk1. Moreover, Propofol could inhibit the effect of LiCl on activating the Wnt/β-catenin signaling pathway in H2O2-induced Eca109 cells.Conclusion:Propofol elicits protective effects to inhibit H2O2-induced proliferation and metastasis and promote apoptosis of Eca109 cells via blocking the Wnt/β-catenin pathway, offering a possible therapeutic modality for ESCC.

Cistanche tubulosa phenylethanoid glycosides induce apoptosis in Eca-109 cells via the mitochondria-dependent pathway.

Cistanche tubulosa has various biological functions. In the present study, the antitumor effect of water-soluble phenylethanoid glycosides of C. tubulosa (CTPG-W) on esophageal cancer was investigated. Eca-109 cells were treated with CTPG-W and the cell viability was measured by MTT assay. The apoptosis, cell cycle, mitochondrial membrane potential (Δψm) and reactive oxygen species were analyzed by flow cytometry. The levels of proteins in apoptotic pathways were detected by western blot analysis. It was determined that CTPG-W significantly reduced the viability of Eca-109 cells through the induction of apoptosis and cell cycle arrest. Following CTPG-W treatment, the Δψm of Eca-109 was notably decreased, which is associated with the upregulated levels of B-cell lymphoma-2 (Bcl-2)-associated X and downregulated levels of Bcl-2. Consequently, the levels of cytochrome c and c-Jun NH2-terminal kinase were increased, which upregulated the levels of cleaved-poly (ADP-ribose) polymerase and cleaved-caspase-3, −7 and −9, but not caspase-8. Correspondingly, the levels of reactive oxygen species in Eca-109 cells demonstrated notable changes. These results indicated that CTPG-W induced apoptosis of Eca-109 cells through a mitochondrial-dependent pathway.

Apoptosis and autophagy induced by DVDMs-PDT on human esophageal cancer Eca-109 cells.

Esophageal cancer is a common gastrointestinal cancer. About 300,000 people die from esophageal cancer every year in the world. Photodynamic therapy (PDT) has attracted attention as a feasible cancer therap for this diagnosis. Sinoporphyrin sodium (DVDMs) is a novel sensitizer isolated from photofrin. In this study, we aimed to investigate the effects of DVDMs mediated photodynamic therapy and the possible mechanism on human esophageal cancer Eca-109 cells. Cell viability was measured by MTT assay and cell apoptosis was determined by Annexin V-PE/7-AAD and western blot. MDC staining and western blot were used to evaluate cell autophagy. The production of intracellular reactive oxygen species (ROS) was detected by flow cytometry. The expression of MAPK and HO-1 were detected by western blot. DVDMs-PDT decreased cell viability and induced cell apoptosis and autophagy. Autophagy inhibition reduced cell apoptosis triggered by DVDMs-PDT in Eca-109 cells. Generation of ROS was detected in DVDMs-PDT group. p38MAPK, JNK and HO-1 were activated after PDT treatment and the activation were reversed by adding ROS scavenger NAC. Our studies demonstrated that DVDMs-PDT induced apoptosis and autophagy in Eca-109 cells. DVDMs-PDT induced ROS generation in Eca-109 cells, and the generation of ROS activated p38MAPK and JNK. Activation of p38MAPK and JNK may be involved in PDT-induced apoptosis.

Long non-coding RNA DANCR promotes cell proliferation, migration, invasion and resistance to apoptosis in esophageal cancer.

Long non-coding RNAs (lncRNAs) have important effects on the development and progression of multiple carcinomas. Our studies aimed to investigate the expression of lncRNA DANCR in esophageal squamous cell carcinoma (ESCC) tissues and paracancerous tissues, and to explore its effect on the cell biological characteristics of ESCC ECA109 cells. The expression of DANCR was detected by qRT-PCR in human ESCC tissues and paracancerous normal tissues in ESCC patients. Small interfering RNA (siRNA) was transfected to knock down the expression of DANCR and interference efficiency was analyzed by qRT-PCR in ECA109 cells. MTT, wound healing, Transwell, TUNEL and flow cytometry (FCM) assay was used to measure the influence of DANCR on proliferation, invasion, migration and apoptosis in ECA109 cells, respectively. The expression of DANCR in ESCC tissues and ESCC cells was significantly higher compared with that in the adjacent normal tissues (P<0.05). Furthermore, cell proliferation, migration and invasion were significantly suppressed by knock-down mediated down-regulation of DANCR expression. On the contrary, cell apoptosis was promoted by silencing of DANCR. According to our research, the expression of DANCR was up-regulated in human ESCC tissues, and the important role that DANCR played in ESCC cells was similar to an oncogene. Therefore, silencing of lncRNA DANCR could have potentially beneficial effects on the prognostic and therapy for ESCC in the future.

Mechanism of Oxymatrine-induced Human Esophageal Cancer Cell Apoptosis by the Endoplasmic Reticulum Stress Pathway.

Endoplasmic reticulum stress is one of the mechanisms of cell apoptosis. In this study, the mechanism of oxymatrine-induced human esophageal cancer Eca-109 cell apoptosis by the endoplasmic reticulum stress pathway was investigated. Eca-109 cells were cultured in vitro with different doses of oxymatrine (0.5, 1, 2 μg/mL) for 48 h. The cell viability and proliferation inhibition rate were examined by MTT assay and cell cycle assay. The apoptosis rate was examined by Annexin V-FITC/propidium iodide assay. The expression of endoplasmic reticulum stress markers, including binding immunoglobulin protein and CCAAT-enhancer-binding protein homologous protein, were determined by real-time quantitative polymerase chain reaction and western blotting, respectively. MTT data showed that oxymatrine significantly inhibited the proliferation of Eca-109 cells. The cell apoptosis rate was quantified by flow cytometry. The expression of binding immunoglobulin protein was markedly downregulated in oxymatrine-treated Eca-109 cells while that of CCAAT-enhancer-binding protein homologous protein was upregulated. Oxymatrine inhibited proliferation and induced apoptosis of human esophageal carcinoma Eca-109 cells. Thus, oxymatrine may be a potential agent for treating human esophageal cancer.

Bufalin induces apoptosis in human esophageal carcinoma ECA109 cells by inhibiting the activation of the mTOR/p70S6K pathway.

The present study examined whether bufalin could induce human esophageal carcinoma ECA109 cells apoptosis via inhibiting the activation of mechanistic target of rapamycin (mTOR)/p70 S6 kinase (p70S6K) pathway is discussed in this article. The present study used the esophageal squamous cell carcinoma ECA109 cell line to assess the apoptosis-inducing effects of bufalin via inhibition of the mTOR/p70S6K pathways. A plasmid containing the wild-type mTOR gene (wtmTOR) was transfected into ECA109 cells. The levels of p70S6K, phosphorylated (p)-p70S6K, cellular inhibitor of apoptosis-1 (cIAP-1) and Bcl-2-associated death promoter (BAD) in ECA109 cells were examined by western blot analysis, and apoptosis was detected by flow cytometry analysis and Giemsa staining. The results revealed that the expression of p-p70S6K was increased as the time progressed (at 0, 12 and 24 h), and then decreased at 30, 36, 42 and 48 h after transfection. The expression of cIAP-1 was significantly decreased as time progressed following the addition of bufalin, whereas that of BAD was increased. The levels of p-p70S6K and cIAP-1 were significantly higher in the wtmTOR-transfected group than in the control and empty vector-transfected groups, and then reduced following addition of bufalin; however, BAD expression was significantly lower in the wtmTOR-transfected group. The results of flow cytometry revealed the cell cycle of ECA109 was arrested at G2/M phase and the apoptotic rate was significantly lower in the wtmTOR-transfected group than in the control and empty vector-transfected groups, and then increased following addition of bufalin. In conclusion, the findings of the present study demonstrated that bufalin induced apoptosis in esophageal carcinoma cells via the inhibition of the mTOR/p70S6K pathway and indicated that treatment with bufalin could be combined with chemotherapy to overcome the resistance of esophageal carcinoma cells to chemotherapeutic-induced apoptosis.

C-terminal binding protein‑2 mediates cisplatin chemoresistance in esophageal cancer cells via the inhibition of apoptosis.

C-terminal binding protein‑2(CtBP2) is a transcriptional co-repressor that is associated with tumorigenesis and tumor progression. It has been reported to predict a poor prognosis in several human cancers, including esophageal squamous cell carcinoma(ESCC). The present study aimed to investigate the involvement of CtBP2 in the cisplatin (DDP) resistance of the ECA109 ESCC cell line and its effect on the expression of apoptosis-associated proteins. Constructed recombinant lentiviruses were used for the knockdown or overexpression of CtBP2 in ECA109 cells, and the expression of CtBP2 was measured using reverse transcription-quantitative polymerase chain reaction and western blotting following transfection. MTT assays, Hoechst33342 staining and flow cytometry (FCM) were applied to detect the influence of CtBP2 on the DDP-induced viability and apoptosis of the transfected ECA109 cells. In addition, the levels of apoptosis-associated proteins, including p53, B‑cell lymphoma2(Bcl‑2), Bcl‑2‑associated X protein (Bax) and activated caspase-3 were investigated in the transfected ECA109 cells. Stable ECA109 cells with CtBP2 overexpression or knockdown were successfully established. The results of the MTT, Hoechst33342 and FCM assays demonstrated that overexpression of CtBP2 attenuated the reduction of cell viability and inhibited the cell apoptosis induced by DDP. Furthermore, the western blotting results indicated that CtBP2 overexpression inhibited the DDP-induced apoptosis of ECA109 cells via the reduction of p53, activated caspase-3 and Bax expression, and promotion of Bcl‑2 expression. Therefore, the present study indicated that CtBP2 reduced the susceptibility of ECA109 cells to DDP by regulating the expression of apoptosis-related proteins, suggesting that it may be a promising therapeutic target in ESCC in the future.

Down-regulation of STAT3 induces the apoptosis and G1 cell cycle arrest in esophageal carcinoma ECA109 cells

BackgroundSignal transducer and activator of transcription 3 (STAT3) is persistently activated in a wide variety of epithelial cancers. Aberrant activity of STAT3 correlates with tumor growth, invasion and metastasis, which makes it a potential therapeutic target of cancer. To explore the biological role of STAT3 in esophageal cancer, we used small hairpin RNA to knockdown the expression of the STAT3 gene in the esophageal carcinoma ECA109 cell line and the cell apoptosis, cell cycle and cell migration were investigated.MethodsThe cell apoptosis was tested using DNA ladder, mitochondrial membrane potential assay, TUNEL assay, annexin V-PI staining. Cell cycle phases were estimated using flow cytometry analysis. The mRNA and proteins related to apoptosis and cell cycle were examined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. And cell migration was investigated by in vitro Transwell assay. The data were analyzed with two-sample Student’s t test and ANOVA followed by the LSD post hoc test.ResultsOur results showed that knockdown of STAT3 in ECA109 cells induced noticeable apoptotic morphological changes like cell shrinkage, apoptotic vacuoles, membrane blebbing time-dependently. In addition, DNA ladder, TUNEL assay, Annexin V-PI staining and declined level of cleaved Caspase-3 indicated that down-regulation of STAT3 could induce apoptosis in ECA109 cells. Flow cytometry analysis displayed the induction of G1-phase cell cycle arrest of ECA109 cells by STAT3 decreasing, consistent with the descend of c-Myc and cyclin D1 in protein levels. Furthermore, STAT3 knockdown suppressed the expression of matrix metalloproteinases-9, sushi domain containing 2 and urokinase plasminogen activator in ECA109 cells and inhibited cell migration ability.ConclusionsKnockdown of STAT3 could induce the apoptosis and G1 cell cycle arrest in esophageal carcinoma ECA109 cells, and inhibit the migration ability of cells as well.

Clinical values of Ku80 upregulation in superficial esophageal squamous cell carcinoma.

Ku80 is an important DNA repair protein. Here, this study sought to investigate clinical impacts of Ku80 expression for patients with superficial esophageal squamous cell carcinoma (ESCC). Immunohistochemical analysis of Ku80 expression was carried out in normal esophageal mucosa, squamous epithelial dysplasia, carcinoma in situ, and superficial ESCC. Its relationships with clinicopathological features and survival of superficial ESCC patients were further clarified. Lentivirus‐mediated RNA interference was used to silence Ku80 gene in ECA109 and KYSE150 cells. Both quantitative real‐time PCR and Western blot were employed to evaluate Ku80 levels. CCK‐8 assay, clone formation assay, flow cytometry, and tumorigenesis experiment were performed to evaluate the malignant phenotype of ECA109 and KYSE150 cells. Increased Ku80 expression was observed in dysplastic esophageal mucosa and carcinoma in situ compared to normal esophageal mucosa (P < 0.001, P < 0.001). Ku80 expression was further increased in superficial ESCC in comparison with dysplastic esophageal mucosa and carcinoma in situ (P < 0.001, P = 0.034). In superficial ESCC, Ku80 overexpression was related to tumor differentiation (P = 0.017), T status (P = 0.011), nodal involvement (P = 0.005), TNM stage (P = 0.004), and postoperative recurrence (P = 0.008). Cox proportional hazards regression showed tumor differentiation, T status, nodal involvement, TNM stage, and Ku80 expression were both independent predictors of patients’ overall survival and disease‐free survival. Ku80 shRNA effectively reduced Ku80 expression, which significantly inhibited proliferation, clone formation, and induced apoptosis in ECA109 and KYSE150 cells. The tumor growth of xenografts was significantly reduced by Ku80 silencing in ECA109 and KYSE150 cells. Ku80 overexpression associates with unfavorable prognosis of superficial ESCC patients, and silencing of Ku80 could inhibit the malignant behavior of ESCC cells. We provide evidence that Ku80 has unrecognized roles in carcinogenesis and development of ESCC.

MicroRNA-133b inhibits cell proliferation and promotes apoptosis by targeting cullin 4B in esophageal squamous cell carcinoma.

microRNAs (miRs) serve a role as modulators during carcinogenesis. It has been demonstrated that the expression of miR-133b is decreased in a variety of tumor tissues and cell lines and serves a suppressive role in the proliferation and apoptosis of different types of tumor cells. However, its effect on esophageal squamous cell carcinoma (ESCC) cells remains unclear. In the current study, the expression of mature miR-133b was measured using reverse transcription-quantitative polymerase chain reaction and the results indicated that miR-133b was significantly downregulated in ESCC tissues and various ESCC cell lines. The overexpression of miR-133b significantly inhibited the proliferation and promoted the apoptosis of KYSE150 and Eca-109 cells. Furthermore, it was demonstrated that cullin 4B (CUL4B) promotes ESCC cell proliferation and inhibits apoptosis by activating the protein kinase B/glycogen synthase kinase 3β/β-catenin pathway. Taken together, these results demonstrate that miR-133b/CUL4B serves a tumor suppressive role during ESCC progression and may therefore be used as a potential target to treat patients with ESCC.

DNA binding, crystal structure, molecular docking studies and anticancer activity evaluation of a copper(II) complex

A copper complex [Cu(HPBM)(l-Phe)(H2O)]·ClO4 (1) (HPBM = 5-methyl-2-(2′-pyridyl)benzimidazole, l-Phe = l-phenylalanine anion) was synthesized and characterized by elemental analysis, IR, ESI–MS, HR–ESI–MS, ESR spectroscopy, and by X-ray single-crystal analysis. The binding constant of the complex with calf thymus DNA (CT-DNA) was determined as 7.38 (± 0.57) × 104 M−1. Further studies indicated that the complex interacts with CT-DNA through minor groove binding. The in vitro cytotoxic activities of both the free proligand and the complex against Eca-109, HeLa and A549 cancer cells and normal LO2 cells were evaluated by the MTT method. The IC50 values range from 5.7 ± 0.1 to 8.3 ± 0.6 µM. Free HPBM displays no cytotoxic activity against the selected cancer cells, with IC50 values more than 100 µM. Double staining analysis showed that the complex can induce apoptosis in Eca-109 cells. Comet assays demonstrated that the complex can damage DNA and cause apoptosis. The complex also induces an increase in intracellular reactive oxygen species and a reduction in mitochondrial membrane potential. The complex can also increase the intracellular Ca2+ level and induce release of cytochrome c. The cell cycle arrest was investigated by flow cytometry. The results demonstrate that the complex induces apoptosis in Eca-109 cells through DNA-binding and ROS-mediated mitochondrial dysfunctional pathways.

Retracted] Effects of cyclin E gene silencing on the proliferation of esophageal cancer cell lines, EC9706, Eca109 and KYSE30.

Subsequently to the publication of this article, an interested reader drew to our attention the fact that the six panels shown in Fig.6 shared several areas of identity among them. Following an internal investigation, a laboratory technician, who was responsible for editing the pictures, admitted that the data as presented in the figure had been manipulated after having mislaid some of the original data. The corresponding author of the article takes responsibility for this oversight, and therefore the paper is to be retracted from publication. All of the named authors agree to this retraction. We deeply regret that these errors were allowed to remain in the paper, and extend our apologies to the readership of the Journal. [the original article was published in Molecular Medicine Reports 7: 799-804, 2013; DOI: 10.3892/mmr.2013.1280].

RACKI induces chemotherapy resistance in esophageal carcinoma by upregulating the PI3K/AKT pathway and Bcl-2 expression.

IntroductionAccumulating evidence indicates that RACK1 is involved in the progression of tumors. We aimed to evaluate the function of RACK1 in esophageal squamous cell carcinoma (ESCC) and its role in the mechanism of chemotherapy resistance.Materials and methodsTransfected ESCC cell lines with plasmids expressed shRACK1 or open reading frame (ORF) targeting RACK1 and established stable cell lines. We then examined the effects of RACK1 on cell proliferation and chemotherapy resistance in ESCC cell lines, and the expression of AKT, pAKT, ERK1/2, Bcl-2, and Bim was introduced to further detect the association between RACK1 and chemotherapy resistance.ResultsThe proliferation ability of ESCC cells was improved in the overexpression RACK1 groups (P<0.001) and decreased in the transfected shRACK1 groups (P<0.001) compared with the control ones. Meanwhile, upregulation of RACK1 significantly suppressed cisplatin-induced apoptosis in Eca109 and EC9706 cells, while downregulation of RACK1 promoted the sensitivity compared to the control group (Eca109: P<0.001 for shRACK1, P<0.01 for shNC, and P<0.001 for overexpression group; EC9706: P<0.001 for shRACK1, P<0.001 for shNC, and P<0.05 for overexpression group). Furthermore, we found that RACK1 could activate the PI3K/AKT pathway and increase the expression level of Bcl-2 in ESCC, which leads to the enhancement of chemoresistance in ESCC.ConclusionRACK1 promotes proliferation and chemotherapy resistance in ESCC by activating the PI3K/AKT pathway and upregulating the Bcl-2 expression.

Celastrus orbiculatus extracts induce cell cycle arrest and apoptosis in human esophageal squamous carcinoma ECA-109 cells in vitro via the PI3K/AKT/mTOR signaling pathway.

Recently, Celastrus orbiculatus ethyl acetate extracts (COE) have been investigated for their anticancer effects on digestive tract tumors. However, the therapeutic effects of COE on esophageal squamous carcinoma cells (ESCC) have not been investigated. In the present study, the effects of COE on the cell cycle and apoptosis of ESCCs were assessed in vitro, and it was revealed that COE treatment triggered G0/G1 cell cycle arrest, and induced DNA damage and apoptosis in a dose-dependent manner in ESCC. Activation of the phosphatidylinositol 3-kinase/protein kinase-B/mechanistic target of rapamycin (mTOR) pathway was also suppressed by COE. Additionally, the combined treatment with COE and rapamycin (an mTOR inhibitor) acted synergistically in ECA-109 cells compared with the treatment with COE or rapamycin alone. These findings extend the understanding of the action of COE and suggest that COE has potential as a treatment option for ESCC as a single treatment or in combination.

Downregulation of YAP inhibits proliferation and induces apoptosis in Eca-109 cells.

A previous study reported that Yes-associated protein (YAP) gene was overexpressed in esophageal squamous cell carcinoma (ESCC); however, the exact role of YAP in ESCC remains largely unclear. The present study aimed to investigate the effects of YAP inhibition on ESCC. In order to investigate the exact role of YAP in ESCC cells, a stable YAP low-expression ESCC cell line was established using YAP-small interfering RNA. MTT assay was performed to examine the cell proliferation ability, while flow cytometry were used to detect the cell apoptosis and cell cycle distribution. In addition, reverse transcription-quantitative polymerase chain reaction and western blot analysis were applied for mRNA and protein level detection, respectively. The results suggested that YAP gene inhibition significantly repressed the ECA-109 cell proliferation and induced cell apoptosis, whereas this inhibition had no significant effects on cell cycle. Furthermore, the expression levels of cell apoptosis-associated proteins were determined in the current study, and the data demonstrated that the B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein ratio and phosphorylated extracellular signal-regulated kinase expression were significantly reduced, while the p53 and caspase 3 levels were notably increased in YAP gene-inhibited ECA-109 cells. In conclusion, the current study revealed that YAP gene inhibition suppresses the proliferation and induces apoptosis in ECA-109 cells, indicating that the YAP gene serves as an oncogene in ESCC.

RNAi-mediated TCF-3 gene silencing inhibits proliferation of Eca-109 esophageal cancer cells by inducing apoptosis.

Esophageal cancer (EC) remains an important health problem in China. In the present study, through the use of siRNA, specific gene knockdown of transcription factor 3 gene (TCF-3) was achieved in vitro and the effect of TCF-3 gene on human EC Eca-109 cell proliferation and apoptosis. Eca-109 cells were treated using negative control (NC) of siRNA against TCF-3 (siTCF-3) and siTCF-3 group. Colony formation assay was used to detect the colony formation ability in Eca-109 cells. MTT assay was used to measure the cell growth and viability, whereas BrDU assay was used to evaluate cell proliferation, and flow cytometry (FCM) to assess cell apoptosis. Reverse-transcription quantitative PCR (RT-qPCR) was applied to measure TCF-3 gene expression. Protein expressions of TCF-3, apoptosis-related proteins, Bcl-2, Bax, and caspase-3 were determined using Western blotting. Transfection of siTCF-3 successfully down-regulated TCF-3 gene expression. In addition, siTCF-3, reduced Eca-109 cell viability and proliferation, in a time-dependent manner, and inhibited progression of cell cycle from G0/G1 to S-stage. When treated with siTCF-3, the Eca-109 cells exhibited increased apoptosis, with up-regulated cleaved caspase and Bax expressions, whereas Bcl-2 expression was down-regulated. The present study shows that TCF-3 gene silencing inhibits Eca-109 cell growth and proliferation, suppresses cell cycle progression, and promotes apoptosis, which might serve as a new objective for EC treatment.

Epigallocatechin-3-gallate promotes apoptosis and reversal of multidrug resistance in esophageal cancer cells

Evidence for demonstrating the role of the green tea component epigallocatechin-3-gallate (EGCG) in esophageal squamous cell carcinoma cells is limited. In this study, we investigated apoptosis induced by EGCG and the underlying molecular mechanisms in human esophageal squamous cell carcinoma cells. The growth-inhibitory effects of EGCG on esophageal cancer cell (Eca109 and Ec9706) were detected by MTT. Using flow cytometry, we determined the cellular apoptosis, bcl-2, bax and caspase-3 protein expression in Eca109 and Ec9706 cells following treatment with EGCG for 24h. After treatment of Eca109/ABCG2 (an esophageal cancer multidrug resistance cell line) cells with adriamycin (ADM) combined with EGCG for 24h, the cellular apoptosis, mitochondrial membrane potential, ADM concentration in cells and ABCG2 protein expression were detected by flow cytometry. EGCG inhibited the growth of Eca109 and Ec9706 cells in a dose- and time- dependent manner. EGCG induced apoptosis, decreased the bcl-2 protein expression and increased the expression of bax and caspase-3 protein. The rate of apoptosis and ADM concentration in the Eca109/ABCG2 cells following treatment with ADM and EGCG were higher than that with ADM treatment alone, although the mitochondrial membrane potential was significantly lower (P<0.01). EGCG reduced the ABCG2 expression of Eca109/ABCG2 cells. Our data indicated that EGCG inhibited cell growth and induced esophageal cancer cell apoptosis. It reduced the bcl-2 protein expression and increased the bax and caspase-3 protein expression. EGCG reversed multi-drug resistance by reducing ABCG2 expression and increasing the anticancer drug concentration in cancer cells.