Inhibitory effects of OK-432 (Picibanil) on cellular proliferation and adhesive capacity of breast carcinoma cells

We investigated the potent inhibitory effects of OK-432 (Picibanil) on both cellular adhesion and cell proliferation of estrogen-dependent (MCF-7) or estrogen-independent (MDA-MB-231) breast carcinoma cells. Cellular proliferation of both MCF-7 and MDA-MB-231 cells was markedly inhibited in a dose-dependent manner, when the carcinoma cells were exposed to OK-432. Cell attachment assay demonstrated that incubation with OK-432 for 24 h reduced integrin-mediated cellular adhesion of both cell types. However, fluorescence activated cell sorter (FACS) analysis revealed that incubation with OK-432 for 24 h did not decrease the cell surface expressions of any integrins. These results suggest that the binding avidity of integrins is reduced by OK-432 without alteration of the integrin expression. We conclude that OK-432 inhibits integrin-mediated cellular adhesion as well as cell proliferation of breast carcinoma cells regardless of estrogen-dependence, and that these actions of OK-432 contribute to prevention or inhibition of breast carcinoma invasion and metastasis.     

蟾蜍灵对乳腺癌干细胞增殖和凋亡的影响

目的:探讨蟾蜍灵对乳腺癌干细胞的增殖和侵袭能力的影响。方法:将人乳腺癌MDA-MB-231细胞系进行培养,采用流式细胞分选技术从中分离出乳腺癌干细胞。CCK-8法检测不同浓度的蟾蜍灵对乳腺癌干细胞增殖的影响。流式细胞术Annexin Ⅴ-FITC/PI双染检测不同浓度的蟾蜍灵对乳腺癌干细胞凋亡的影响。结果:成功从MDA-MB-231细胞系中分选出乳腺癌干细胞。CCK-8结果显示,蟾蜍灵呈时间、浓度依赖性抑制乳腺癌干细胞增殖。流式细胞术结果显示蟾蜍灵随时间和浓度增加诱导乳腺癌干细胞凋亡率增加。 结论:蟾蜍灵能够抑制乳腺癌干细胞的增殖,并诱导其凋亡。     

PNCK对鼻咽癌细胞增殖和凋亡作用的研究

目的 研究妊娠上调的非泛素性钙调蛋白激酶(Pregnancy-upregulated nonubiquitous calmodulin kinase,PNCK)在鼻咽癌组织中的表达以及对鼻咽癌细胞增殖和凋亡的作用。方法 采用免疫组织化学方法检测鼻咽癌癌组织和正常组织中PNCK表达水平。构建慢病毒载体干扰PNCK基因表达,并采用Real time PCR和免疫印迹结果证实,采用MTT方法、流式细胞术、Caspase3和Caspase7活性检测鼻咽癌肿瘤细胞增殖和凋亡的变化。结果 免疫组织化学结果显示PNCK蛋白在鼻咽癌癌组织中呈特异性高表达。Real time PCR和免疫印迹结果证实慢病毒成功干扰鼻咽癌CNE-2Z细胞中PNCK表达(PNCK基因在mRNA和蛋白水平表达受到显著抑制)。MTT检测结果显示抑制PNCK表达抑制CNE-2Z细胞增殖。此外,干扰PNCK表达引起CNE-2Z细胞Caspase3和Caspase7活性上升,流式细胞术表明干扰PNCK基因表达可以促进CNE-2Z细胞凋亡。结论 干扰PNCK基因表达抑制鼻咽癌细胞增殖并诱导肿瘤细胞凋亡,可能是治疗鼻咽癌的潜在靶点。     

Effects of dietary fatty acids on the proliferation, adhesion and metastatic potential of breast cancer cells: an experimental review

The dietary fat hypothesis postulates that dietary or exogenously derived fatty acids play an important role in the carcinogenesis, evolution and/or progression of breast cancer. In order to reveal possible underlying mechanisms of this hypothesis, we studied the influence of ω- 3 polyunsaturated fatty acids (PUFAs) -α-linolenic (ALA), eicosapentaenoic (EPA) and docosahexaenoic (DHA)-, ω-6 PUFAs-linoleic (LA), γ-linolenic (GLA) and arachidonic (ARA)- and monounsaturated ω- 9 oleic acid (OA) on the proliferation, adhesion and metastatic potential of human breast cancer cells in culture. GLA and the ω-3 PUFAs, ALA and DHA, inhibited significantly the cell growth of MCF-7 and MDA-MB-231 breast cancer cell lines, while EPA has less marked inhibitory effects. ω-6 PUFAs, LA and ARA, or ω- 9 OA had either no effect or caused a slight increase of proliferation. The attachment of breast cancer cells to the extracellular matrix components (type IV collagen, fibronectin and Matrigel) was significantly inhibited by ω-6 GLA and ω-3 PUFAs ALA, DHA and EPA. At concentrations which had no effect on cell growth over the duration of experiments the ω-6 PUFAs, LA and GLA, and the ω-3 PUFAs, ALA, DHA and EPA, had the ability to inhibit both cellular migration and invasion into type IV collagen and Matrigel. In summary, our findings indicate important differences in the ability of ω-3, ω-6 and ω-9 fatty acids to modulate prolif eration, attachment to extracellular matrix components, mo-tility and invasiveness of human breast carcinoma cells in vitro, with the GLA and all ω-3 PUFAs being the most effective inhibitors. Our data are consistent with the view that the type rather than the amount of dietary fatty acids is be more important in breast cancer development and progression.     

FRNK抑制人乳腺癌细胞体外增殖及机制研究

目的：研究黏着斑相关非激酶（focal adhesion kinase related non—kinase，FRNK）对人乳腺癌MCF-7细胞增殖的抑制作用及相关机制。方法：通过RT—PCR方法克隆目的基因FRNK，构建pcDNA3．1-FRNK重组质粒；经脂质体分别介导重组质粒（pcDNA3．1-FRNK）、阳性对照质粒（pcDNA3．1-GFP）和空质粒（pcDNA3．1）转染MCF-7细胞，以正常MCF-7细胞作为空白对照；通过检测转染后细胞FRNK蛋白的表达，并结合转染pcDNA3．1-GFP后细胞表达荧光的多寡来评估转染效率；采用MTT法研究转染后12、24、48和72h各时间点细胞的增殖情况；转染质粒48h后，采用流式细胞术分析MCF-7细胞周期，Westernblot法检测细胞核内NF-κBp65的表达。结果：pcDNA3．1-FRNK质粒可经脂质体介导高效转染MCF-7细胞，促进细胞FRNK的表达，FRNK表达量在转染后48h达高峰；转染pcDNA3．1-FRNK后，MCF-7细胞增殖趋缓，且这种抑制增殖呈一定的时间依赖性；转染FRNK基因后，S＋G2／M期的细胞比例较正常细胞显著下降（P〈0．05）；转染pcDNA3．1-FRNK后MCF-7细胞核内NF-teBp65蛋白表达减少。结论：FRNK可抑制MCF-7细胞增殖，其抑制作用与下调NF-κBp65核易位相关。     

XAV939对肝癌细胞增殖及糖酵解的影响

目的：探讨 Wnt／β－catenin 信号通路特异性抑制剂 XAV939对肝癌细胞增殖及糖酵解过程的影响。方法：MTT 方法检测不同浓度 XAV939对肝癌细胞 Bel －7402、HCCLM3增殖能力的影响;Western blot 方法检测 XAV939对肝癌 Bel －7402、HCCLM3细胞 Wnt／β－catenin 信号通路关键基因和其下游靶基因表达的影响,以及对糖酵解过程中关键调控基因表达的影响。运用 SPSS 19．0统计软件分析各组间的差异。结果：MTT 结果表明不同浓度的 XAV939能够不同程度的抑制 Bel －7402、HCCLM3细胞增殖能力,XAV939对两种细胞的抑制率接近50％时,浓度分别为：30μmol／L、20μmol／L。Western blot 结果显示,XAV939可以显著抑制 Wnt／β－catenin 及其下游基因 c －myc、Cyclin D1的表达,有效抑制β－catenin 信号通路活性;同时,XAV939可以通过抑制 HK －2、LDHA 而非 Glut －1的蛋白表达水平来抑制肝癌细胞的糖酵解过程。结论：XAV939在体外能够有效抑制肝癌细胞 Wnt／β－catenin 信号通路及其依赖性细胞增殖和糖酵解过程。     

青蒿琥酯对人胃癌细胞增殖及凋亡的影响

目的:研究青蒿琥酯对胃癌细胞增殖和凋亡的作用,探讨其对胃癌作用机制,为进一步的临床研究及应用提供依据。方法:采用MTT噻唑蓝法观察青蒿琥酯对胃癌细胞MGC-803生长增殖的影响,流式细胞仪和透射电镜检测药物作用前后细胞凋亡,逆转录-聚合酶链反应测定药物作用前后凋亡抑制基因survivin表达的变化。结果:青蒿琥酯在3.125~50μg/ml浓度范围内呈剂量依赖性方式抑制胃癌细胞MGC-803的生长增殖,并能显著抑制胃癌细胞survivin基因的表达。流式细胞仪检测出凋亡峰,透射电镜下可见部分MGC-803细胞呈典型的凋亡形态学改变。结论:青蒿琥酯能显著抑制胃癌细胞生长,并诱导胃癌细胞凋亡。     

Cell surface heparan sulfate proteoglycans control adhesion and invasion of breast carcinoma cells

Background

Cell surface proteoglycans interact with numerous regulators of cell behavior through their glycosaminoglycan chains. The syndecan family of transmembrane proteoglycans are virtually ubiquitous cell surface receptors that are implicated in the progression of some tumors, including breast carcinoma. This may derive from their regulation of cell adhesion, but roles for specific syndecans are unresolved.

Methods

The MDA-MB231 human breast carcinoma cell line was exposed to exogenous glycosaminoglycans and changes in cell behavior monitored by western blotting, immunocytochemistry, invasion and collagen degradation assays. Selected receptors including PAR-1 and syndecans were depleted by siRNA treatments to assess cell morphology and behavior. Immunohistochemistry for syndecan-2 and its interacting partner, caveolin-2 was performed on human breast tumor tissue arrays. Two-tailed paired t-test and one-way ANOVA with Tukey’s post-hoc test were used in the analysis of data.

Results

MDA-MB231 cells were shown to be highly sensitive to exogenous heparan sulfate or heparin, promoting increased spreading, focal adhesion and adherens junction formation with concomitantly reduced invasion and matrix degradation. The molecular basis for this effect was revealed to have two components. First, thrombin inhibition contributed to enhanced cell adhesion and reduced invasion. Second, a specific loss of cell surface syndecan-2 was noted. The ensuing junction formation was dependent on syndecan-4, whose role in promoting actin cytoskeletal organization is known. Syndecan-2 interacts with, and may regulate, caveolin-2. Depletion of either molecule had the same adhesion-promoting influence, along with reduced invasion, confirming a role for this complex in maintaining the invasive phenotype of mammary carcinoma cells. Finally, both syndecan-2 and caveolin-2 were upregulated in tissue arrays from breast cancer patients compared to normal mammary tissue. Moreover their expression levels were correlated in triple negative breast cancers.

Conclusion

Cell surface proteoglycans, notably syndecan-2, may be important regulators of breast carcinoma progression through regulation of cytoskeleton, cell adhesion and invasion.     

LRRK2在乳腺癌细胞增殖和耐药中的作用及其机制研究

目的:探讨LRRK2在乳腺癌组织中的表达及其对乳腺癌细胞增殖、凋亡及耐药的作用和分子机制.方法:采用实时荧光定量PCR(qRT-PCR)和Western blot检测了48例乳腺癌组织及其配对正常组织中LRRK2表达;并检测人正常乳腺上皮细胞MCF-10A、乳腺癌细胞株MCF-7、MDA-MB-231、BT-483及阿...     

二氢青蒿素诱导乳腺癌细胞凋亡的分子机制初探

48 h凋亡相关蛋白tbid和Caspase-8表达增强,且呈一定剂量依赖关系.结论: DHA能显著抑制人乳腺癌细胞T47D生长,影响细胞周期,诱导细胞凋亡,其分子机制可能与促使Bim、tbid和Caspase-8表达增强的内源性凋亡途径有关.     

Dominant-negative E-cadherin alters adhesion and reverses contact inhibition of growth in breast carcinoma cells

Cadherins play a crucial role in epithelial morphogenesis and mediate intercellular adhesion. These receptors bind catenins and are involved in signal transduction pathways that regulate cell growth and apoptosis, and are frequently down-regulated in invasive and metastatic carcinomas. In order to assess the role of E-cadherin in cell adhesion and growth, we transfected MCF-7 cells, a human breast cancer cell line, with a dominant-negative construct of E-cadherin (H-2kd-E-cad). The dominant-negative form of E-cadherin disrupted cell-cell adhesion of monolayer cells and induced an epithelial-to-fibroblastic conversion without any significant change in integrin profiles. Whereas control cells rapidly formed multicellular aggregates that tightly compacted into spheroids, dominant-negative transfected cells failed to compact and remained as loosely-associated cells. The transfectants exhibited down-regulation and redistribution of endogenous E-cadherin as well as increased levels of alpha- and beta-catenin. Importantly, the H-2kd-E-cad-transfected cells, when grown as multicellular aggregates, showed an increase in cell proliferation rate, compared to control cells. Overall, these observations suggest that in breast carcinoma, disruption of E-cadherin and catenin function modulates both cell-cell adhesion and permits escape from cell-cell contact-involved inhibition of cell growth.     

Akt抑制剂MK2206对乳腺癌细胞增殖和凋亡的影响

目的:研究新型Akt抑制剂MK2206对体外培养的人乳腺癌T47D和MDA-MB-231细胞株增殖和凋亡的影响,并初步探讨其可能的作用机制。方法:以不同浓度的MK2206作用于人乳腺癌T47D和MDA-MB-231细胞,采用MTT法检测细胞的增殖抑制率,FCM法检测细胞的凋亡率,Western印迹法检测细胞中caspase-3、多聚ADP核糖聚合酶(polyADP-ribosepolymerase,PARP)、bcl-2、bax、磷酸化Akt(phosphorate-Akt,p-Akt)和总Akt(total-Akt,T-Akt)蛋白表达水平的变化。结果:0.1、1、10和100nmol/LMK2206作用细胞24h后,可明显抑制T47D和MDA-MB-231细胞的增殖和诱导细胞凋亡,其作用随着药物浓度的增加而增强。MK2206可促进乳腺癌细胞中caspase-3和PARP蛋白剪切,上调bax蛋白表达,下调bcl-2和p-Akt蛋白的表达,且均呈剂量依赖性,但对T-Akt表达却无明显影响。结论:MK2206可抑制乳腺癌T47D和MDA-MB-231细胞的增殖并诱导其凋亡,其机制可能与抑制Akt磷酸化从而阻断PI3K/Akt信号转导途径有关。     

血管内皮生长因子对肝癌细胞侵袭能力和同质性粘附作用影响

目的　观察血管内皮细胞生长因子 (VascularEndothelialGrowthFactorVEGF)诱导肝癌HepG2 细胞转移及其对细胞同质性粘附作用的影响。方法　采用3 H -TdR掺入及鼠尾胶粘附试验测定VEGF对肝癌HepG2 细胞同质性粘附作用以及Bodyen -Chamber观察VEGF诱导肝癌细胞转移作用。 结果　 1ng/ml、5ng/mlVEGF诱导HepG2 细胞 6 0min、90min、12 0min3 H -TdR掺入实验 (dpm/min)分别为 175 8.6 7± 2 89.4 6、1380 .0 3± 32 8.5 5、2 6 5 7.4 3± 310 .31和 312 4 .3± 2 2 6 2 .14、2 2 4 5 .6±2 73.2 4、2 0 91.5 2± 2 13.84 ,10ng/mlVEGF诱导HepG2 细胞 6 0min、90min、12 0min ,3 H -TdR掺入实验 (dpm/min)分别为12 32 .32± 2 0 1.0 4、2 337.5± 333.0 4、2 2 36 .99± 2 37.0 7,显著低于对照组 6 0、90、12 0min的 2 184 .4 9± 336 .0 3、35 6 0± 2 5 5 .17、4 337.4± 377.35 ,(P <0 .0 5或 0 .0 1) ;用VEGF 1ng/ml、5ng/ml、10ng/ml培养肝癌细胞 2h ,下室浸润的肝癌细胞数分别为5 .75± 1.0 0、17.17± 2 .38、10 .33± 0 .88× 10 4/ml,分别高于对照组 1.5 8± 0 .38× 10 4/ml,(P <0 .0 5或 0 .0 1)。结论　VEGF可以促进肝癌HepG2 细胞转移 ,与VEGF降低肝癌细胞的同质性粘附作用有关。     

Ribosomal phosphoprotein P0 interacts with GCIP and overexpression of P0 is associated with cellular proliferation in breast and liver carcinoma cells

The ribosomal acidic P0 protein, an essential component of the eukaryotic ribosomal stalk, was found to interact with the helix-loop-helix protein human Grap2 and cyclin D interacting protein (GCIP)/D-type cyclin-interacting protein 1/human homolog of MAID protein. Using in vivo and in vitro binding assays, we show that P0 can interact with the N and C termini of GCIP via its N-terminal 39-114 amino-acid residues. Although the P0-GCIP complex was detected mainly in cytoplasmic fraction, polysome profile analysis indicated that the P0-GCIP complex did not coelute with either polysomes or 60S ribosomes, suggesting that GCIP associates with the free form of P0 in the cytoplasm. Transfection of GCIP into MCF-7 cells resulted in decreased levels of pRb phosphorylation. Cotransfection of P0 with GCIP, however, resulted in GCIP-mediated reduction of pRb phosphorylation level which was repressed by P0. Furthermore, overexpression of P0 in breast cancer and hepatocellular cancer cell lines promoted cell growth and colony formation compared to control transfectants. Overexpression of P0 also increased cyclin D1 expression and phosphorylation of pRb at Ser780. Interestingly, P0 mRNA was overexpressed in 12 of 20 pairs of breast cancer/ normal breast specimens (60%). Together, these data indicate that P0 overexpression may cause tumorigenesis in breast and liver tissues at least in part by inhibiting GCIP-mediated tumor suppression.     

The effects of chemotherapy on morphology, cellular proliferation, apoptosis and oncoprotein expression in primary breast carcinoma.

The use of chemotherapy as a form of primary treatment for breast cancer is increasing and, as a result, more resection specimens contain tumours which have been exposed to cytotoxic drugs. We have studied the effects of chemotherapy on the tumour morphology and various biological features of breast carcinoma in a group of 35 patients. These were a group who responded to treatment in a clinical study of the use of primary chemotherapy designed to reduce tumour bulk prior to surgery. Characteristic morphological changes, temporally related to the administration of cytotoxic agents, are seen. The malignant cells become enlarged with vacuolated cytoplasm and vesicular nuclei containing prominent nuclei; occasionally the nuclei were angular and hyperchromatic. These features are interpreted as degenerative in nature. In 15 cases sufficient material was present in the pretreatment biopsies to compare the grade of the tumours before and after chemotherapy: changes were found in six tumours. Cytotoxic drugs do not induce a consistent pattern of change in the proliferation and apoptotic indices of individual tumours, but there is a tendency to reduce proliferative activity over all the tumours as a group. It was also found that chemotherapy is capable of modifying the expression of the oncoproteins c-erbB-2 and p53 in a minority of cases of breast cancer, usually resulting in an acquisition of immunoreactive oncoprotein. It is important to be aware of these effects when studying breast carcinomas removed after chemotherapy.     

Estrogen responsive proliferation of clonal human breast carcinoma cells in athymic mice

A clone of MCF-7 (MCF-7ED), a cell in continuous in vitro cultivation derived from an estrogen-responsive human breast carcinoma, requires estrogen supplementation for progressive exponential (doubling time: 50–85 h) tumor growth in the mammary fat of athymic mice. The plasma concentration of estradiol which stimulated exponential growth of MCF-7ED corresponded to physiologic premenopausal levels in women. The tumors were carcinomas with murine and MCF-7ED cells intermixed. MCF-7ED cells could be repurified in subcultures of mixed tumors. Comparative studies of breast and non-breast cell lines showed concordance between the presence of estradiol receptor, sensitivity to the anti-estrogen tamoxifen for growth in vitro, and estradiol dependence for tumorigenic growth in athymic mice. Progesterone alone did not stimulate MCF-7ED growth, but acted synergistically with estrogen. Progesterone's action was to decrease tumor latent period, not to increase final tumor incidence or growth rate. Under estrogen-deficient conditions, conditions approximating postmeno-pausal status in women, (10^?10 M in plasma), a dormant state was established between MCF-7ED cells and murine mammary stroma which could be maintained several months. The dormant state could be broken by introduction of estradiol, but not progesterone. This system should be useful for defining host and cancer cell determinants in estrogen-responsive breast cancer growth.     

The role of focal adhesion kinase catalytic activity on the proliferation and migration of squamous cell carcinoma cells

Focal adhesion kinase (FAK) is upregulated in several epithelial tumours and there has been considerable interest in developing small molecule kinase inhibitors of FAK. However, FAK also has important adaptor functions within the cell, integrating signals from both integrins and growth factors. To investigate the role of FAKs kinase domain, we generated fak-deficient squamous cell carcinoma (SCC) cell lines. Re-expression of a wild type or kinase dead FAK allowed us to delineate its kinase dependent functions. In addition, we used the novel FAK kinase inhibitor PF-562,271. The kinase activity of FAK was important for tumour cell migration and polarity but more striking was its requirement for the anchorage independent 3 dimensional (3D) proliferation of SCC cells and their growth as xenografts in mice. Inhibition of FAK activity and prevention of growth in 3D correlated with Src inhibition. We further identified a mechanism whereby FAK regulates proliferation in 3D via regulation of the kinase activity of Src. This was dependent on the kinase activity of FAK and its resulting phosphorylation on Y397 that provides a high affinity binding site for Src. These data support the further development of FAK kinase inhibitors as agents that have the potential to inhibit both tumour cell migration and proliferation.     

Effects of arsenic trioxide on the cellular proliferation, apoptosis and differentiation of human neuroblastoma cells

A human neuroblastoma cell line, IMR-32, was used as an in vitro model system to study the effects of arsenic trioxide (As(2)O(3)) on aggressive human neuroblastoma. From 0.5 micro M, As(2)O(3) exhibited a dose-dependent inhibition of IMR-32 proliferation. At concentrations of 1.5 micro M or higher, As(2)O(3) up-regulated caspase 3, leading to cellular apoptosis. However, neurofilament-200 kDa and tyrosine hydroxylase were not up-regulated, implying minimal neuronal differentiation. Concomitantly, TrkA was down-regulated and TrkB up-regulated. Pre-treatment with the protein kinase C (PKC) inhibitor Ro-31-8220 partially blocked As(2)O(3)-mediated apoptosis, meaning that As(2)O(3) might signal through PKC activation. The results suggest that As(2)O(3) might be potentially useful in neuroblastoma.