目的 观察下调Ras同源类似物E (RhoE)表达对人乳腺癌细胞231生物学行为的影响。 方法 蛋白质印迹技术检测小干扰RNA（siRNA）转染前后RhoE在乳腺癌细胞231中的表达；RhoE siRNA的细胞转染 用lipofectamine?2000脂质体法；Cell Counting Kit-8检测转染细胞及对照细胞的增殖变化；损伤刮擦试验和体外侵袭实验（Transwell小室）分别检测转染细胞及对照细胞的迁移与侵袭能力。 结果 RhoE在乳腺癌细胞231中的表达较高；成功转染RhoE siRNA的乳腺癌细胞，蛋白质印迹显示RhoE的表达被明显的抑制；RhoE的表达被抑制后对乳腺癌细胞的增殖、迁移和侵袭有着明显的促进作用。 结论 下调RhoE 表达能够明显促进乳腺癌细胞的增殖﹑迁移和侵袭，RhoE可能在乳腺癌的发生发展中起着重要作用。
目的:探讨表没食子儿茶素没食子酸酯(EGCG)对乳腺癌细胞MCF7生长的影响及对乳腺癌细胞MDAMB231迁移的影响。方法:MCF7细胞培养贴壁之后,加入EGCG处理,2d后收集蛋白,采用Western Blot检测磷酸化p38丝裂原活化蛋白激酶(phosphop38MAPK)的表达;同样处理后收集活细胞,用细胞计数法检测细胞的存活;取对数生长期的MDAMB231细胞,分至6孔板培养,使用EGCG处理后,采用细胞划线法探测乳腺癌细胞的迁移。结果:使用EGCG处理乳腺癌细胞后,phosphop38MAPK的表达降低,EGCG处理乳腺癌细胞4d后其增殖率降低50%,迁移活性降低。结论:EGCG处理乳腺癌细胞能抑制肿瘤细胞的生长以及迁移,这与p38MAPK信号通路相关。
Objective To observe the outcomes of using different concentrations of arsenic trioxide at varying phases on the breast cancer cell line MCF-7 and to study the mechanism of this effect. Methods The effect of arsenic trioxide on the growth of breast cancer cell line MCF-7 was observed after applying arsenic trioxide of different concentrations （0.5-16 μmol/Ｌ）. The inhibitory effect of arsenic trioxide on the cell proliferation was investigated with 3-(4，5-dimethyl-thizazol-2-yl)-2， 5-diphenyl tetrazolium bromide (MTT) and the induction of arsenic trioxide on cell apoptosis was detected by DNA ladder and terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). Results The effect of arsenic trioxide on breast cancer cell line MCF-7 depended on the phase and the dose. The number of cell decreased significantly and there were conspicuously typical morphological changes of apoptosis after the use of arsenic trioxide， including membrane blebbing， chromatin pyknosis, nuclear fragmentation and the formation of apoptotic body. The typical DNA ladders were observed in the MCF-7 cells after 48 h administration of arsenic trioxide at concentrations 1-8 μmol/Ｌ. Significant elevations of apoptosis index at 24 h, 48 h and 72 h were all detected by TUNEL after incubating with 4 μmol/L arsenic trioxide. Conclusion Arsenic trioxide may inhibit the growth of breast cancer cell line MCF-7 significantly by inducing the apoptosis of breast cancer cell.
ObjectiveTo investigate the effect of expressions of nucleoside transporters subtype (hENT1 and hENT2) on 5-fluorouracil(5-FU) cytotoxicity in breast cancer cell lines(MDA-MB-231, MDA-MB-468, SK-BR-3, MCF-7). MethodsFour breast cancer cell lines were chosen to detect the mRNA expressions of hENT1 and hENT2 by RT-PCR. Cells were incubated in the medium with a serial concentrations of 5-FU from 1.28×104 ng/L to 2.00×108 ng/L for 48 h. Then the cell proliferation in each cell line was measured by MTT assay and the IC50 was evaluated. Results①The mRNA expressions of hENT1 and hENT2 in the MDA-MB-231, MDA-MB-468, or SK-BR-3 cells were significantly higher than thoes in the MCF-7 cells(P < 0.05). The mRNA expression of hENT2 was detected in the MDA-MB-231, MDA-MB-468, or SK-BR-3 cells, not detected in the MCF-7 cells. 2MTT showed that IC50 of 5-FU in the MDAMB-231, MDA-MB-468, or SK-BR-3 cells was significantly lower than that in the MCF-7 cells(P < 0.05). There was no statistical difference of IC50 among the three lines(MDA-MB-231, MDA-MB-468, and SK-BR-3)(P > 0.05).③The three lines(MDA-MB-231, MDA-MB-468, and SK-BR-3) with lower IC50 of 5-FU highly expressed hENTs, and MCF-7 cell with the higher IC50 of 5-FU expressed less hENTs. ConclusionsThe expressions of hENTs in breast cancer cell lines can significantly influence 5-FU cytotoxic effect. It is implicated that the hENTs expressions might be the clue to the choice of nucleoside anticancer drugs in clinic.
ObjectiveTo isolate cancer stem cells (CST) from human breast cancer cell line (MCF-7) and study their sensitivity toward oxidative stress.MethodsMCF-7 cells were cultured in serum-free suspension culture medium to identify cells forming the sphere phenotype. The morphological changes of MCF-7 cells were observed by inverted phase contrast microscope (compared with MCF-7 cells cultured in serum-free suspension culture medium). The expression of CST marker CD133 was detected by immunocytochemical staining in CST cell spheres (experimental group) with a diameter of 100 μm and MCF-7 cells (control group) with a fusion degree of 70%. The positive rate of CD133 was detected by flow cytometry in the third generation of tumor cells with diameter of 150 μm. The second generation of tumor globular cells (experimental group) with diameter of 150 μm and corresponding MCF-7 cells (control group) were taken to be damaged by 50 mol/L H2O2 for 120 minutes. The expression of DNA damage marker histone H2AX phosphorylation (γH2AX) was detected by immunocytochemical staining.ResultsInverted phase contrast microscopy showed that MCF-7 cells grew initially in a single-cell adherent state, then aggregated and grew in serum-free suspension culture medium, and finally formed CST cell spheres, while the control MCF-7 cells cultured in MCF-7 cell culture medium grew extensively and could not grow in suspension. Fluorescence microscopy showed that the expression of CD133 in MCF-7 cells of control group was negative, while that in experimental group was positive. Flow cytometry showed that CD133 was positive in CST cells, and the positive rate was 92%. Inverted fluorescence microscopy showed that the expression of γH2AX in CST tumor spheres of experimental group was significantly lower than that in MCF-7 cells of control group after 120 minutes of H2O2 injury.ConclusionSerum-free suspension culture medium can produce globular CST cells from MCF-7 tumor cell line, which have strong antioxidant damage.
ObjectiveTo investigate the effects of phenethyl isothiocyanate (PEITC) on apoptosis and proliferation of breast cancer SK-BR-3 cells. MethodsSK-BR-3 cells were treated with different concentrations (0, 10, 30, 50 μmol/L) of PEITC respectively. The proliferation capacity of SK-BR-3 cells was detected by MTT and BrdU staining methods. The cell apoptosis was detected by TUNEL and flow cytometry methods. The protein and mRNA expressions levels of indexes related apoptosis such as Bcl-2, Bax, and MCL-1 and indexes related endoplasmic reticulum stress (ERS) such as PERK, eIF2α, CHOP, IRE1α, ATF6α were detected by Western blot and quantitative real-time PCR (qRT-PCR), respectively. ResultsCompared with the control group (0 μmol/L PEITC treatment group), the results of MTT and BrdU staining methods showed that the proliferations of SK-BR-3 cells in the 10, 30 and 50 μmol/L PEITC treatment group were decreased in turn with the increase of concentration. The results of TUNEL and flow cytometry methods showed that the apoptosis rates of SK-BR-3 cells in the 10, 30 and 50 μmol/L PEITC treatment group were increased in turn with the increase of concentration. The results of Western blot and qRT-PCR methods showed that the protein and mRNA expression levels of anti-apoptotic indexes (Bcl-2, MCL-1) were decreased with the increase of concentration, while the expression levels of protein and mRNA of the pro-apoptotic index (Bax) and ERS-related indexes (PERK, eIF2α, CHOP, IRE1α, ATF6α) increased with the increase of concentration. ConclusionFrom the preliminary results of this study, PEITC can promote the apoptosis of breast cancer SK-BR-3 cells and inhibit cell proliferation, which might be achieved by regulating the expression levels of indexes related apoptosis and ERS.