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To investigate the effect of 2-methoxyestradiol (2-ME2) to lymphoma Raji cells and its mechanism.Different concentrations of 2-ME2 were used to treat lymphoma Raji cells. CCK8 method was used to detect the effect of 2-ME2 to proliferation of Raji cells. Flow cytometry FITC/PI double labeling method was used to detect early apoptosis of the cells. Western blotting was used to detect the effect of 2-ME2 to the expression of BCL-2, Bax, Caspase-3 and C-myc proteins in Raji cells.2-ME2 significantly inhibited the proliferation of Raji cells. The inhibition rate increased with the increasing of drug concentration, and increased significantly with the prolongation of drug treatment time (r=0.9215). Flow cytometry FITC/PI double staining showed that the apoptotic rate of 2.5 μmol/L 2-ME2 treatment group was (33.79±1.63) %, while the apoptosis rate of the 48 h group was (51.90±2.72) %, and that of the control group was (7.08±0.36) %. After treated with 2.5 μmol/L 2-ME2 for 12 h, the expression of Bax protein was up-regulated, BCL-2 protein was down-regulated, caspase-3 protein expression was up-regulated, and C-myc protein expression was down-regulated, all of them showed a time-dependent relationship.2-ME2 shows obvious inhibitory effect on lymphoma Raji cells in a dose- and time-dependent manner. Its mechanism of treatment on lymphoma Raji cells may be related to up-regulation of Bax/BCL-2 ratio and activation of Caspase-3 to induce apoptosis in cancer cells. Down-regulation of C-myc protein expression also participates in the apoptotic process.2-甲氧基雌二醇上调Bax/BCL-2比例诱导淋巴瘤Raji细胞凋亡的研究.研究2-甲氧基雌二醇（2-ME2）对淋巴瘤Raji细胞的作用及其作用机制.用不同浓度2-ME2作用于淋巴瘤Raji细胞，CCK8法检测2-ME2对Raji细胞增殖的影响；流式细胞仪FITC/PI双标法检测细胞早期的凋亡；蛋白印迹法检测2-ME2对Raji细胞BCL-2、Bax、Caspase-3、C-myc蛋白表达的影响.2-ME2对Raji细胞的增殖具有明显抑制作用，其抑制率随着药物浓度的增高而增加，随着药物作用时间的延长而显著增高（r=0.9215）。流式细胞仪FITC/PI双染色法结果显示，2.5 μmol/L 2-ME2处理24 h组的细胞凋亡率为（33.79±1.63）%，而48 h组的凋亡率高达（51.90±2.72）%，对照组Raji细胞为（7.08±0.36）%。2.5 μmol/L 2-ME2处理Raji细胞12 h后，蛋白印迹检测结果显示，Bax蛋白表达上调，BCL-2蛋白下调，而Caspase-3蛋白表达亦上调，C-myc蛋白表达下调，之间均具有时效性关系.2-ME2对淋巴瘤Raji细胞具有明显的抑制作用，且呈剂量和时间依赖性。其对淋巴瘤Raji细胞的作用机制可能与上调Bax/BCL-2比例，激活Caspase-3诱导癌细胞凋亡有关，下调C-myc蛋白表达也参与了凋亡过程.

To explore the effect of 2-methoxyestradiol (2-ME2) on apoptosis of human acute T lymphoblastic leukemia cells, and its underlying mechanism.The growth inhibition of CEM cells was detected by MTT assay; apoptotic cells were detected by DNA laddering analysis; the expressions of P53 mRNA and protein were detected by RT-PCR and Western blot respectively.2-ME2 remarkably inhibited the CEM cell growth and the 50% growth inhibitory concentration (IC50) at 48 h was 2 µmol/L. The DNA ladder could be detected in CEM cells after treating with 2 µmol/L 2-ME2 for 24, 48 and 72 hours; after treating with 2 µmol/L 2-ME2 for 24, 48 and 72 hours, a time-dependent reduction of P53 mRNA and protein expressions was found in CEM cells.The anti-leukemia effect of 2-ME2 is completed through the induction of cell apoptosis. Down-regulation of P53 gene expression may be an underlying mechanism.

This study was aimed to explore the synergistic effect of 2-methoxyestradiol (2-ME2) and bortezomib (Bor) on the proliferative inhibition and apoptosis of U266 cell line and its possible mechanism. The cells were treated with 2-ME2, Bor alone and 2-ME2 combined with Bor, respectively. The cell viability and proliferative curve were detected by CCK8, the cell apoptosis was detected by caspase 3/7 activity test, cell cycle status was analyzed by flow cytometry, and real-time PCR was used to detect the mRNA expression of P21, BAX and BCL-2. The results showed that compared with cells treated with 2-ME2 or Bor alone, the proliferative potential of cells in combination group was significantly inhibited (p0.05), and apoptosis rate markedly increased (p0.05), cell cycle was arrested at G(1)-S phase, the mRNA expressive level of P21 and BAX increased, while the expression of BCL-2 decreased. It is concluded that 2-ME2 combined with Bor synergistically inhibits cell proliferation and induces apoptosis in U266 cell line. The possible mechanism may be associated with its effect of up-regulating P21 and BAX expressions.

The purpose of this study was to explore the mechanism underlying the regulation of 2-methoxyestradiol (2-ME)-induced cell apoptosis by mcl-1 and bax gene in myelodysplastic syndrome (MDS). The MUTZ-1 cells were pretreated with 2-ME; then the activity of caspases-3 was determined by fluorescent colorimetry; the mRNA expressions of apoptosis-related genes (mcl-1) and bcl-2-related X protein (bax) were determined by RT-PCR. The results showed that as compared with control, the 2-ME enhanced the activity of caspase-3 in MUTZ-1 cells in a dose-and time-dependent manners (p0.05); along with increasing of 2-ME concentration, the expression of intracellular mcl-1 mRNA reduced (p0.05), meanwhile the expression level of mcl-1 mRNA negatively correlated to the activity of caspase-3 at the corresponding time points (r=-0.992, p0.01), but the expression of bax mRNA did not show significant change (p0.05). It is concluded that 2-ME can regulate the apoptosis of MDS cells through the pathway of down-regulating the expression of mcl-1 mRNA and activating the caspase-3.

The aim of this study was to investigate the effects of 2-methoxyestradiol (2-ME) on expressions of caspase-3 and survivin in chronic myelocytic leukemia (CML) K562 cells. The experiment was divided into 3 groups: control group, in which K562 cells were cultured in medium without 2-ME; the experimental group, in which K562 cells were cultured in medium containing different concentrations of 2-ME (1, 2, 4, 8 and 16 micromol/L) for 36 hours; the negative control group, in which K562 cells were replaced by distilled water without RNase in medium. The apoptosis rate, the protein and its mRNA expressions of caspase-3 and survivin of K562 cells was detected by TUNEL, flow cytometry (FCM), half-quantitative RT-PCR respectively. The results showed that the apoptosis rate of K562 cells in experimental group was significantly higher than that in control group (p0.05). The apoptosis rate of K562 cells detected by FCM was almost the same as that detected by TUNEL method (p0.01). The result detected by TUNEL methods was positively correlated with that detected by FCM (gamma = 0.845, p = 0.034). The expression of caspase-3 protein increased in a concentration-dependent manner, and also this expression level in the experimental group was higher than that in the control group (p0.05); the expression of survivin protein decreased along with the increasing of 2-ME concentration. and the difference between the experimental group and the control group was statistically significant (p0.05). The expression of caspase-3 mRNA was higher in the experimental group than that in the control group (p0.01), and the expression of survivin mRNA was lower in the experimental group than that in the control group (p0.01). The expression level of caspase-3 mRNA was negatively correlated with that of survivin (gamma = -0.966, p = 0.001). It is concluded that the 2-ME can induce apoptosis of K562 cells in a concentration-dependent manner and indicate its promising potential in the treatment of CML patients.

The aim of this study was to investigate apoptotic effect of 2-methoxyestradiol (2-ME2) on K562 cells and its mechanism. K562 cells were treated with different concentrations of 2-ME2. MTT assay was used to examine the effect inducing growth inhibition. DNA fragmentation assay and Annexin V-FITC/PI staining were used to detect the effect of apoptosis. The change of mitochondrial transmembrane potential was analyzed by flow cytometry. The expressions of related gene mRNA and/or proteins were detected by RT-PCR and Western blot respectively. The results indicated that the 2-ME2 inhibited proliferation of K562 cells in a time- and dose-dependent manners and the concentration of 50% growth inhibition (IC(50)) was 2 micromol/L at 48 hours. 2-ME2 induced DNA ladder and significantly increased apoptosis in K562 cells when exposed to 2 micromol/L of 2-ME2 for 24, 48 and 72 hours, the result of Annexin-V/PI staining showed that rates of the apoptotic cells were 13.78%, 22.32% and 29.43% respectively, which was remarkably higher than that of control (1.78%) (p0.05). The FCM analysis showed that the mitochondrial transmembrane potential in K562 cells lowered after exposed to 1, 2 and 4 micromol/L of 2-ME2 for 24 hours. 2-ME2 down-regulated the expression of bcr/abl and bcl-2, up-regulated the expression of bax mRNA, and down-regulated protein expressions of bcl-2, procaspase-3, procaspase-9, PARP (116 kD) and p-Akt, and up-regulated expression of cytoplasmic Cyto-C and PARP 85 kD apoptosis-related cleavage fragment protein, but had no effect on total Akt protein in K562 cells after treated with 2 micromol/L of 2-ME2 for 24, 48 and 72 hours. It is concluded that the 2-ME2 can induce the apoptosis and inhibit the proliferation of K562 cells by increasing the ratio of bax/bcl-2, reducing the mitochondrial transmembrane potential, releasing cytochrome C to cytoplasm, initiating the mitochondrial apoptosis pathway and leading in turn to caspase-3 activation. These findings suggest that interfere PI3K/Akt signal pathway via down-regulating the expression of bcr/abl mRNA is implicated in the effect of 2-ME2 on K562 cells.

The study was aimed to investigate the mechanism of proliferation inhibition and apoptosis of MDS-RAEB MUTZ-1 cells induced by 2-methoxyestradiol (2-ME), the cell proliferation was determined by MTT assay, apoptosis rate was determined with annexinV-FITC/PI double staining and cell cycle was analyzed by flow cytometry (FCM) after MUTZ-1 cells were treated with different concentrations of 2-ME; the changes of morphologic features of MUTZ-1 cells were observed with Wright-Giemsa's staining; lactate dehydrogenase was determined by Beckman Counter; and agarose gel electrophoresis was used to verify whether 2-ME can induce apoptosis of MUTZ-1 cells. The results showed that 2-ME inhibited the proliferation of MUTZ-1 cells in a dose-and time-dependent manner and caused a sustained arrest at G(2)/M phase in MUTZ-1 cells; the typical apoptotic morphological features appeared in MUTZ-1 cells; the production of lactate dehydrogenase was up-regulated and the marked DNA ladder pattern of internucleosomal fragmentation was observed. It is concluded that the mechanism of proliferation inhibition and apoptosis of MUTZ-1 cells induced by 2-ME is probably related with the G(2)/M cell cycle arrest; 2-ME may be a potentially adjunctive anticancer drug useful to treat myelodysplastic syndrome.

In order to investigate the differentiation-inducing effect of 2-methoxyestradiol (2ME2), an estrogen derivative, on CD138+ (Syndecan-1) primary myeloma cells from 7 patients with myeloma, primary myeloma cells from 7 patients were enriched by using CD138 immunomagenetic beads. The enriched CD138+ (Syndecan-1) myeloma cells treated with 0.5 micromol/L 2ME2 for 36 h and 72 hours were used to observe the differentiation changes with expression of CD49e and to quantitatively detect the light-chain secretion in the supernatants. The results indicated that 2ME2 caused morphological and immunophenotypic changes with light-chain secretion in the supernatant, and the typical features of differentiation of CD138+ (Syndecan-1) primary myeloma cells. CD138+ (Syndecan-1) myeloma cells became more and more mature in morphology, with decreased ratio of nucleus to plasma, disappearance of nucleoli, and pyknosis of chromatin. The result of detecting the expression of CD49e of CD138+ (Syndecan-1) myeloma cells showed the obvious up-regulation of CD49e expression after exposure to 2ME2 for 72 hours. Quantitative assay for light chain secretion in the supernatant of bone marrow CD138+ cells from patients showed remarkable increment at 72 hours. It is concluded that lower concentrations of 2-methoxyestradiol can induce differentiation of bone marrow CD138+ cells from multiple myeloma patients.

This study was aimed to investigate whether 2-methoxyestradiol (2ME2) could exert effect of inducing differentiation on myeloma cells. A myeloma cell line CZ-1 secreting lambda light chain protein was used as an object of study. The CZ-1 cell morphology was observed by Wright's staining, the CD49e expression on cell surface after treatment with 2ME2 was detected by flow cytometry, the concentration of lambda light chain protein in the supernatant was assayed by immuno-scattering turbidity method. The results showed that treatments with 0.1-0.5 micromol/L 2ME2 for 72 hours resulted in some mature morphological changes of CZ-1 cells, such as the ratio of karyoplasms going down, nucleolus reducing or disappearing, chromatin getting rougher and more compacted; the CD49e positive CZ-1 cells increased by 2ME2 with concentrations of 0.1 micromol/L to 0.5 micromol/L in a concentration-dependent manner. The statistical difference from the control group was significant; the concentration of lambda light chain protein increased from control group 29.3 +/- 2.77 microg/ml to 35.97 +/- 2.6 microg/ml (P0.05) after exposure to 0.1 micromol/L 2ME2 for 72 hours, and the treatment of 0.5 micromol/L 2ME2 up-regulated lambda light chain protein to 79.67 +/- 1.88 microg/ml (P0.01) continuously. It is concluded that 2ME2 at low-concentration can induce differentiation of the CZ-1 cells to mature, which provides a new, and safe strategy for myeloma therapy.

The objective was to explore the in vitro effects of growth inhibition and apoptosis induction of 2-methoxyestradiol (2ME2), an estrogen derivative, on seven myeloma cell lines NCI-H929, HS-sultan, KM3, SKO-007, CZ-1, U266 and LP-1and to observe its synergistic effects in combination with some other drugs, such as dexamethasone, As(2)O(3), thalidomide and zoledronic acid. Seven myeloma cell lines NCI-H929, HS-sultan, KM3, SKO-007, CZ-1, U266 and LP-1 were cultured at different concentrations with or without dexamethasone, As(2)O(3), thalidomide and zoledronic acid. Cell viability was assessed by trypan blue assay, plasma cell labeling index (PCLI) was detected by BrdU assay, terminal-deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay were used to determine apoptosis cells in situ. Synergistic effects of 2ME2 in combination with other drugs were judged by King's formula. The results showed that after treatment with 1, 4, 8, 12, 16 micromol/L 2ME2 at 12, 24, 36 and 48 hours respectively, 2ME2 caused a dose- and time-dependent inhibition of the cell viability. The concentration of 50% growth inhibition (IC(50)) was between (20.8 +/- 0.27) and (34.1 +/- 0.57) micromol/L. After treatment with 12 micromol/L 2ME2 within 24 hours, 2ME2 led to a progressive decline in the fraction of S-phase cells by BrdU assay, plasma cell labeling index (PCLI) declined from (30.14 +/- 4.28)% to (14.71 +/- 6.27)% (P0.05). After treatment with 1, 4, 8, 12, 16 micromol/L 2ME2 at 12, 24, 36 and 48 hours respectively, 2ME2 can induce a dose- and time-dependent apoptosis of myeloma cell lines. The percentage of apoptosis was between 9% - 33% (P0.05). Q value of synergistic effects was between 1.13 to 1.43. It is concluded that 2ME2 can inhibit proliferation and induce apoptosis of myeloma cell lines and has synergistic effects with dexamethasone, As(2)O(3), thalidomide and zoledronic acid.