MEK/ERK信号通路在RANKL诱导的乳腺癌MCF-7细胞迁移中的作用及机制探讨

目的探讨细胞外调节蛋白激酶(ERK)信号通路在核因子-κB受体活化因子配体(RANKL)诱导的乳腺癌细胞MCF-7迁移中的作用。方法流式细胞术检测MCF-7细胞表面核因子-κB受体活化因子(RANK)蛋白的表达;Western blot检测RANKL刺激后磷酸化ERK(p-ERK)及ERK的表达;Transwell法测定RANKL刺激后细胞迁移能力的改变。结果 MCF-7细胞表面表达RANK蛋白,RANKL(2μg/mL)显著诱导MCF-7细胞迁移能力增强。RANKL刺激后MCF-7细胞p-ERK表达逐渐升高,MEK抑制剂PD98059显著抑制RANKL诱导的MCF-7细胞迁移。结论 ERK信号通路参与RANKL诱导的乳腺癌细胞MCF-7迁移。     

RANKL和破骨细胞

细胞核因子κB受体活化因子配基（RANKL）与破骨细胞（OC）表面的细胞核因子κB受体活化因子（RANK）结合，经肿瘤坏死因子受体连接因子（TRAF）介导，激活c-Src、Jun氨基末端激酶（JNK）、核因子κB，调节OC的形成和活性。RANKL也参与成骨细胞与OC间的信息传递。     

PI3K/AKT信号通路在RANKL诱导的SGC-7901胃癌细胞迁移中的作用

目的文献报道RANKL/RANK/OPG途径与肿瘤细胞迁移及骨转移密切相关,但RANKL/RANK途径是否参与胃癌细胞迁移,尚无文献报道。本文拟检测RANK在胃癌细胞系SGC-7901细胞中的表达,并进一步探讨磷脂酰肌醇-3-激酶/丝苏氨酸蛋白激酶(PI3K/Akt)信号通路在RANKL诱导的胃癌细胞迁移中的作用。方法 West-ern blot检测SGC-7901细胞表面RANK蛋白的表达;RANKL刺激后磷酸化Akt(P-Akt)及Akt的表达;Transwell法测定RANKL及抑制剂刺激后细胞迁移能力的改变。结果 SGC7901细胞表达RANK蛋白。RANKL(1μg/mL)诱导SGC-7901细胞迁移能力增强,迁移增加率为57.2%±5.9%,RANKL抑制剂rOPG(5μg/mL)显著抑制RANKL诱导的细胞迁移(13.88%±3.57%,P<0.05)。RANKL刺激后30 min～3 h,SGC-7901细胞p-Akt表达升高,应用PI3K的抑制剂LY294002(50 mmol/L)显著抑制RANKL诱导的胃癌细胞SGC-7901的迁移(57.28%±5.91%vs23.18%±2.79%,P<0.05)。结论胃癌细胞系SGC-7901细胞表达受体RANK,PI3K/Akt信号通路参与RANKL诱导的SGC-7901细胞迁移。     

RANKL与骨代谢

核因子κB受体活化因子配基(receptor activator of NF-κB Ligand,RANKL)是一种Ⅱ型跨膜蛋白,是目前发现的惟一具有诱导破骨细胞分化、发育、发挥功能的因子。NF-κB受体激活子(receptor activatorof NF-κB,RANK)是一种Ⅰ型跨膜蛋白,是RANKL的惟一受体,是RANKL发挥功能的关键。骨保护蛋白(osteoprotegerin,OPG)是一种分泌型糖蛋白,与RANKL竞争性与RANK结合抑制骨吸收、促进骨形成。近年来通过许多对RANKL的研究发现,它不仅在骨质疏松症的发病中起重要作用,而且也在骨代谢过程中受多种因素影响,并为骨质疏松症及其他骨骼疾病的治疗开辟了广阔的前景。     

RANKL和破骨细胞

细胞核因子kB受体活化因子配基(RANKL)与破骨细胞(OC)表面的细胞核因子kB受体活化因子(RANK)结合,经肿瘤坏死因子受体连接因子(TRAF)介导,激活c-Src、Jun氨基末端激酶(JNK)、核因子kB,调节OC的形成和活性。RANKL也参与成骨细胞与OC间的信息传递。     

OPG/RANKL/RANK信号通路在非酒精性脂肪性肝病进展中的作用

非酒精性脂肪性肝病(NAFLD)已成为全球范围内最常见的肝脏疾病,在现有基础上更好诊断、治疗NAFLD也愈发迫切。骨保护素(OPG)/NF-κB受体活化因子(RANKL)/NF-κB受体活化因子受体(RANK)信号通路是参与骨代谢平衡的重要信号通路。分别介绍了OPG、RANKL、RANK及OPG/RANKL/RANK系统,简述了OPG/RANKL/RANK信号通路通过激活NF-κB调节炎症因子生成,促使NAFLD发展的研究现状。指出OPG/RANKL/RANK系统可作为NAFLD治疗的潜在新靶点。     

脂肪组织对骨代谢的调节关系

骨代谢的调节是一个复杂的过程,其本质是调节成骨细胞和破骨细胞的活动。通过破骨细胞吸收旧骨和成骨细胞形成新骨这两个相互偶联又相互制约的骨转换过程,骨组织不断地进行骨重建,以对自身进行新陈代谢~([1])。成骨细胞分泌核转录因子(NF)-κB受体活化因子配体(RANKL),破骨细胞分泌NF-κB受体活化因子(RANK)。RANKL与RANK结合后,传递信号,激活NF-κB,从而促进破骨细胞增     

雷公藤多苷对2型糖尿病肾脏疾病大鼠肾脏保护作用的研究

目的观察雷公藤多苷对STZ诱导的糖尿病肾脏疾病(DKD)大鼠肾脏中细胞核因子κB受体活化因子/核因子κB受体活化因子配体(RANK/RANKL)的表达变化,探讨其保护肾脏的机制。方法采用高糖高脂喂养加STZ腹腔注射法建立T2DM动物模型,造模成功后随机分为DKD模型组(DKD,n=8)和雷公藤多苷组(DT,n=8),另选健康大鼠作为正常对照组(NC,n=8)。DT组予雷公藤多苷50mg/(kg·d)剂量灌胃,NC组和DN组每日予等量生理盐水灌胃。12周后处死大鼠,检测FPG、FIns、UAlb、BUN、Scr、Ucr,计算Ccr。PAS染色观察肾脏病理改变,免疫组织化学法检测肾脏中RANK、RANKL的表达分布,Western blot检测RANK、RANKL、Nephrin的蛋白表达。结果与NC组比较,DKD组FPG、FIns、UAlb、Ccr、BUN在给药12周末表达均升高,肾脏中RANK[(0.27±0.05)vs(0.68±0.11)]、RANKL[(0.23±0.07)vs(0.62±0.08)]蛋白表达增加,而Nephrin表达水平下降(P0.01);与DN组比较,DT组上述生化指标均改善,肾脏病理改变减轻;RANK[(0.45±0.09)vs(0.68±0.11)]、RANKL[(0.39±0.06)vs(0.62±0.08)],而Nephrin蛋白表达增多(P0.01)。结论雷公藤多苷可以抑制RANK/RANKL的表达,减轻T2DM大鼠肾脏病理改变,减少蛋白尿,起到肾脏保护作用。     

26届全美骨矿盐研究学会年会会议纪要

本文对26届全美骨矿盐研究学会年会的主要内容进行总结,本次年会的规模宏大,基础和临床研究方面均取得较多的进展。基础研究方面主要集中在Wnt—低密度脂蛋白受体相关蛋白(Lrp)—Catenin和成骨细胞;骨保护素(OPG)—核因子-κB受体活化因子(RANK)配体(RANKL)—RANK和破骨细胞;力学刺激和骨细胞;维生素D的作用机制;以及性激素的作用机制等方面。临床方面主要报道了钙剂、维生素D及其衍生物、双膦酸盐、激素替代治疗、选择性雌激素受体调节剂(SERM)、降钙素及其他防治骨质疏松的药物研究进展。     

T淋巴细胞在雌激素缺乏状态下对破骨细胞的影响

雌激素缺乏是导致绝经后女性破骨细胞活化的重要因素。雌激素缺乏一方面可促进胸腺T细胞输出，诱导T细胞活化和增殖，导致骨髓活化T细胞增多而促进破骨细胞形成；另一方面通过促炎细胞因子进一步增强活化T细胞的破骨作用。活化的T细胞不仅表达核因子-κB受体活化因子配体（RANKL）和巨噬细胞集落刺激因子（M—CSF）等促骨吸收因子，抑制成骨细胞分化和形成，直接参与破骨过程；而且其产生的肿瘤坏死因子．仪还可与骨髓基质细胞表达的RANKL和M-CSF协同作用，增强破骨前体细胞对RANKL的敏感性，促进破骨细胞的发育和功能，引起骨形成和骨吸收的失衡，最终导致骨丢失增加。     

Breast cancer cells interact with osteoblasts to support osteoclast formation.

Breast cancers commonly cause osteolytic metastases in bone, a process that is dependent upon osteoclast-mediated bone resorption. Recently the osteoclast differentiation factor (ODF), better termed RANKL (receptor activator of NF-kappaB ligand), expressed by osteoblasts has been cloned as well as its cognate signaling receptor, receptor activator of NFkappaB (RANK), and a secreted decoy receptor osteoprotegerin (OPG) that limits RANKL's biological action. We determined that the breast cancer cell lines MDA-MB-231, MCF-7, and T47D as well as primary breast cancers do not express RANKL but express OPG and RANK. MCF-7, MDA-MB-231, and T47D cells did not act as surrogate osteoblasts to support osteoclast formation in coculture experiments, a result consistent with the fact that they do not express RANKL. When MCF-7 cells overexpressing PTH-related protein (PTHrP) were added to cocultures of murine osteoblasts and hematopoietic cells, osteoclast formation resulted without the addition of any osteotropic agents; cocultures with MCF-7 or MCF-7 cells transfected with pcDNAIneo required exogenous agents for osteoclast formation. When MCF-7 cells overexpressing PTHrP were cultured with murine osteoblasts, osteoblastic RANKL messenger RNA (mRNA) levels were enhanced and osteoblastic OPG mRNA levels diminished; MCF-7 parental cells had no effect on RANKL or OPG mRNA levels when cultured with osteoblastic cells. Using a murine model of breast cancer metastasis to bone, we established that MCF-7 cells that overexpress PTHrP caused significantly more bone metastases, which were associated with increased osteoclast formation, elevated plasma PTHrP concentrations and hypercalcaemia compared with parental or empty vector controls.     

siRNA干扰LOX基因对乳腺癌细胞株侵袭性影响的研究

目的检测赖氨酰氧化酶（LOX）基因在低侵袭性乳腺癌细胞MCF-7和高侵袭性乳腺癌细胞MDA-MB-231中的表达差异,并探讨LOX基因对乳腺癌细胞生物学行为的影响。方法 RT-PCR扩增MCF-7和MDA-MB-231LOX基因,采用SYBR G reen I实时荧光定量RT-RCR技术相对定量两种细胞的LOX基因表达。瞬转MDA-MB-231,并于转染后24、48、72 h行体外运动试验侵袭实验,观察干扰LOX基因表达后对MDA-MB-231侵袭的影响。结果 MDA-MB-231较MCF-7高表达LOX基因（P〈0.05）。MDA-MB-231细胞中LOX mRNA在转染48 h表达下降明显。干扰LOX表达后,体外运动实验结果显示RNA i组中MDA-MB-231细胞穿过微孔滤膜到达下室面的细胞数少于未转染组和阴性对照组（P均〈0.05）。结论 MDA-MB-231细胞高表达LOX基因,干扰其LOX基因表达后细胞的侵袭运动能力明显减弱。     

白藜芦醇对人乳腺癌骨高转移细胞株MDA-MB-231BO生长抑制和凋亡的影响

目的观察白藜芦醇（Res）对人乳腺癌骨高转移细胞株MDA-MB-231BO生长抑制和凋亡的影响,探讨其在抑制乳腺癌骨转移中的应用价值。方法将0、12.5、50、100、200μmo/L的Res分别与MDA-MB-231BO细胞作用24、48、72 h;用CCK-8法检测MDA-MB-231BO细胞的生长抑制率,流式细胞仪分析细胞周期并检测细胞凋亡率,荧光显微镜观察细胞形态。结果随Res浓度的增加及作用时间的延长,MDA-MB-231BO细胞的生长抑制率逐渐升高,S期细胞逐渐增多。Res浓度为200μmol/L、作用48 h,MDA-MB-231BO生长抑制率为82.17%±5.37%、早期凋亡率为4.48%±1.23%、晚期凋亡率为9.48%±2.30%,荧光显微镜下观察用药组随着Res浓度的增加,凋亡细胞逐渐增多。结论Res能抑制人乳腺癌骨高转移细胞株MDA-MB-231BO细胞增殖,使MDA-MB-231BO细胞阻滞于S期,并可诱导该细胞凋亡。     

CIK对地西他滨增敏乳腺癌MDA-MB-231细胞的杀伤机制探讨

目的 观察地西他滨（DAC）增敏细胞因子介导的杀伤细胞（CIK）对人乳腺癌MDA-MB-231细胞株的细胞毒作用,并探讨其增敏机制.方法 取对数生长期的乳腺癌MDA-MB-231及正常乳腺MCF-10A细胞,MMT法检测DAC及TRAIL对乳腺癌细胞的增殖抑制率,LDH法检测DAC单用或联合肿瘤坏死因子相关凋亡诱导配体（TRAIL）及CIK对乳腺癌细胞的杀伤率,流式细胞仪检测细胞凋亡率.结果 DAC对乳腺癌细胞MDA-MB-231及正常乳腺上皮细胞MCF-10A无明显杀伤作用.TRAIL对MDA-MB-231有明显杀伤作用,作用24h的IC50约为100 ng/mL,然而对MCF-10A无明显促凋亡影响.5∶1、10∶1、20∶1效靶比的CIK对MDA-MB-231的杀伤率分别为10.7％±1.2％、17.8％±2.1％、37.2％±3.4％,对MCF-10A无杀伤作用.经50 μmol/L的DAC预处理乳腺癌细胞MDA-MB-231 24 h后,5∶1、10∶1、20∶1效靶比的CIK对MDA-MB-231的杀伤率分别为18.6％±2.6％、26.3％±4.5％、51.6％±6.6％,与相应单独效靶比的CIK杀伤作用比较,P均＜0.01.结论 DAC增敏CIK对乳腺癌MDA-MB-231细胞的杀伤敏感性,对正常的乳腺上皮细胞无影响,DAC联合CIK可能成为治疗乳腺癌患者的新途径.     

MT(1) melatonin receptor overexpression enhances the growth suppressive effect of melatonin in human breast cancer cells

Melatonin inhibits the proliferation of estrogen receptor alpha (ERalpha)-positive (MCF-7), but not ERalpha-negative (MDA-MB-231) breast cancer cells. Here, we assessed the effect of MT(1) melatonin receptor stable overexpression in MCF-7 and MDA-MB-231 breast cancer cells on the growth-suppressive effects of melatonin. Parental and vector-transfected MCF-7 cells demonstrated a modest, but significant, growth-suppressive response to melatonin; however, melatonin treatment of MT(1)-transfected MCF-7 cells resulted in significantly enhanced growth-suppression. This response was blocked by an MT1/MT2 melatonin receptor antagonist. Interestingly, MT(1)-overexpression did not induce a melatonin-sensitive phenotype in melatonin-insensitive MDA-MB-231 cells. Finally, Northern blot analysis demonstrated an enhanced inhibition of ERalpha mRNA expression and an enhanced induction of pancreatic spasmolytic polypeptide (pS2) by melatonin in MT(1)-transfected MCF-7 cells relative to vector-transfected MCF-7 cells. These data suggest the involvement of the MT(1) melatonin receptor in mediation of melatonin effects on growth-suppression and gene-modulation in breast cancer cells.     

Phytocompounds of Anonna muricata leaves extract and cytotoxic effects on breast cancer cells

Objective: To identify the phytochemical compounds from Annona muricata(A. muricata) and to determine their in vitro anti-proliferative activities against breast cancer cells, MCF7 and MDA-MB-231. Methods: A. muricata leaves were successively extracted by soxhlet method using n-hexane, ethyl acetate and methanol, and decocted with water. Each extract was analysed by gas chromatography mass spectrometry(GCMS) and characterized with Wiley and NIST library searches. Anti-proliferative activity of each extract was evaluated on MCF7 and MDA-MB-231 breast cancer cells using MTT assay. Results: The GCMS analysis of different solvent extracts of A. muricata leaves showed presence of different chemical groups of compounds such as steroids, terpenoids, phenolic compounds, sugars, sugars alcohol and others including vitamin E. Ethyl acetate leaves extract exhibited the lowest IC_(50) value on the MDA-MB-231 breast cancer cell and n-hexane leaves extract showed the the lowest IC_(50) value on the MCF-7 breast cancer cell. Conclusion: Steroids and phenolic compounds were the main phytocompound groups identified from all A. muricata leaves extracts. The antiproliferative activity of n-hexane and ethyl acetate extract towards breast cancer MCF7 and MDA-MB-231 respectively might be due to the presence of biologically active compounds in the extracts, hence, providing some scientific evidences of the effectiveness of its traditional usages.     

The combined use of <Emphasis Type="Italic">Camellia sinensis</Emphasis> and metronomic zoledronic acid in a breast cancer-induced osteolysis mouse model

Purpose

In previous studies, we demonstrated that green tea (Camellia sinensis, CS) water extract had potent anti-tumor and anti-metastasis effects in the 4T1 mouse breast cancer xenograft model, and the metronomic regimen (0.0125 mg/kg twice a week for 4 weeks) of zoledronic acid (ZOL) was also effective in decreasing tumor burden and metastasis when compared with the conventional regimen. This study aimed to investigate the combined use of CS water extract and metronomic ZOL against tumor metastasis and bone destruction in MDA-MB-231-TXSA human breast cancer.

Methods

Female nude mice were injected with MDA-MB-231-TXSA cells into the marrow space of tibia and were treated with CS water extract and/or metronomic ZOL for 4 weeks. Tumor growth and metastasis to lungs and livers were assessed by in vivo bioluminescence imaging. Abilities of migration and invasion of MDA-MB-231-TXSA cells were also evaluated in vitro.

Results

Our results demonstrated that combination of CS and ZOL had the most potent effects on tumor burden and metastasis to bone, lung and liver, while treatment with CS or ZOL alone significantly protected the bone from cancer-induced osteolysis. In vitro, the combined use of CS + ZOL significantly inhibited MDA-MB-231-TXSA cell migration and invasion. Mechanistic zymography studies showed that the enzyme activities of MMP-9 and MMP-2 were significantly suppressed by CS and CS + ZOL.

Conclusions

The combination of CS plus metronomic ZOL demonstrated potent anti-tumor, anti-metastasis and anti-osteolysis effects against breast cancer, suggesting the potential clinical application against breast cancer patients.