Livin蛋白在乳腺癌中的表达及与Bcl-2关系

目的 探讨凋亡抑制基因Livin和Bcl-2蛋白在乳腺癌组织中表达及与临床病理参数的关系.方法 应用western blot和免疫组织化学SP法检测90例乳腺癌、30例乳腺良性病变和15例乳腺癌旁组织中Livin和Bel-2蛋白的表达情况,分析两种蛋白表达的相关性.结果 Livin蛋白在乳腺癌组织中的阳性表达率及蛋白表达量明显高于癌旁组织和乳腺良性病变,差异有显著性(P＜0.05).Livin蛋白在乳腺癌中的阳性表达与肿瘤大小,组织学类型,组织学分级及淋巴结转移无关(P＞0.05),但随临床分期的增加而升高(P＜0.05);Livin和BcI-2蛋白在乳腺癌组织中的表达显著相关(P＜0.05).结论 Livin蛋白在乳腺癌组织巾表达上调,且与病理分期有关,提示Livin蛋白可通过抑制细胞凋亡促进乳腺癌的发生、发展,Livin与Bel-2蛋白可能在乳腺癌的演进中起着协同作用.     

Livin蛋白在乳腺癌中的表达及与Bcl-2的关系

目的 探讨凋亡抑制基因Livin和Bel-2蛋白在乳腺癌组织中表达及与临床病理参数的关系。方法应用western blot和免疫组织化学SP法检测90例乳腺癌、30例乳腺良性病变和15例乳腺癌旁组织中Livin和Bcl-2蛋白的表达情况,分析两种蛋白表达的相关性。结果Livin蛋白在乳腺癌组织中的阳性表达率及蛋白表达量明显高于癌旁组织和乳腺良性病变,差异有显著性（P〈0．05）。Livin蛋白在乳腺癌中的阳性表达与肿瘤大小,组织学类型,组织学分级及淋巴结转移无关（P〉0．05）,但随临床分期的增加而升高（P〈0．05）;Livin和Bel-2蛋白在乳腺癌组织中的表达显著相关（P〈0．05）。结论Livin蛋白在乳腺癌组织中表达上调,且与病理分期有关,提示Livin蛋白可通过抑制细胞凋亡促进乳腺癌的发生、发展,Livin与Bel-2蛋白可能在乳腺癌的演进中起着协同作用。     

乳腺癌组织中血管内皮生长因子和抑癌基因Maspin 的表达及意义

目的:探讨血管内皮生长因子(vascular endothelial growth factor,VEGF)和抑癌基因Maspin(mammary-serpin)在乳腺癌组织中的表达。方法:采用免疫组织化学法法检测乳腺癌组织与癌旁正常组织中的VEGF和Maspin表达水平。结果:VEGF在正常乳腺组织中表达率为44.4%(40/90),在乳腺癌组织中的表达率为91.1%(82/90),Maspin在正常乳腺组织中表达率为100%(90/90),在乳腺癌组织中的表达率为68.9%(62/90)。VEGF蛋白表达水平与乳腺癌TNM分期、淋巴结转移有关(P<0.01),Maspin蛋白的表达与乳腺癌的组织学分型、分级、淋巴结转移均有关(P<0.05)。结论:检测VEGF和Maspin有利于乳腺癌的生物学行为评估和乳腺癌预后判断。     

MMP-3与乳腺癌上皮间质转化的关系及其意义

为了探讨MMP-3在乳腺癌中表达与乳腺癌上皮间质转化的关系及其在乳腺癌浸润转移中的作用.采用免疫组织化学检测正常乳腺组织、乳腺癌癌旁组织、乳腺癌组织中MMP-3、Claudin-1、Vimentin的表达情况.研究发现:1)MMP-3在乳腺癌组织的阳性表达率较癌旁组织及正常乳腺组织高且具有统计学意义(P<0.05).Claudin-1在乳腺癌中的阳性表达率明显低于癌旁组织及正常乳腺组织具有统计学意义(P<0.05).Vimentin在乳腺癌组织阳性表达率高于癌旁组织及正常乳腺组织具有统计学意义(P<0.05);2)随着乳腺癌病理分期的增加MMP-3表达逐渐增加,同时出现Claudin-1蛋白表达降低及Vimentin蛋白表达升高.相关分析表明MMP-3与Claudin-1的表达呈负相关(r=-0.301,P=0.019),与Vimentin的表达呈正相关(r=0.378,P=0.03),Claudin-1与Vimentin的表达呈负相关(r=-0.278,P=0.031).结果提示,MMP-3可能是通过介导乳腺癌细胞发生上皮间质转化来参与乳腺癌的浸润转移.     

乳腺癌组织中PI3K/AKT信号通路相关蛋白表达

目的研究PI3K/AKT信号传导通路中Her-2、PI3K、AKT以及bcl-2在乳腺癌中的表达及其与临床特征、预后的相关性。方法用免疫组化SP法检测31例乳腺癌和癌旁组织中Her-2、PI3K、AKT以及bcl-2的表达。结果 Her-2、PI3K、AKT在乳腺癌中的表达率分别为45.2%、90.3%、67.7%,均明显高于癌旁组织(P<0.05),而bcl-2在乳腺癌中的表达率为58.1%,在癌旁组织中的表达率为83.9%,(P<0.05);乳腺癌组织中,Her-2、PI3K、AKT、bcl-2的表达均与年龄无相关性(P>0.05);Her-2、AKT在乳腺癌中的表达和组织学分级呈正相关(P<0.05),bcl-2的表达和组织学分级呈负相关(P<0.05),PI3K的表达与组织学分级无明显相关性(P>0.05);AKT的表达在有淋巴结转移时表达率较高,与无淋巴结转移组相比差异有显著性(P<0.05),bcl-2的表达在有淋巴结转移时表达率较低,与无淋巴结转移组相比差异有显著性(P<0.05),Her-2、PI3K的表达与淋巴结转移无明显相关性(P>0.05)。结论 Her-2、AKT的过表达和bcl-2的低表达和乳腺癌的形成和进展有关,检测Her-2、AKT以及bcl-2的表达可用于判定乳腺癌的恶性程度,并可作为判断预后的指标。     

乳腺癌中Abi1和c-Abl及WAVE 2的表达及其相互关系

目的研究乳腺癌组织中Abi1、c-Abl和WAVE2蛋白的表达及其相互关系。方法应用免疫组化SP法检测66例乳腺癌组织和24例正常乳腺组织中Abi1、c-Abl和WAVE2蛋白的表达情况。结果 1.正常乳腺组织与乳腺癌组织相比,Abi1和WAVE2蛋白表达有显著性差异(P0.05),而c-Abl蛋白表达无显著性差异(P0.05),但有定位的改变。2.Abi1强阳性率与乳腺癌的肿瘤大小、组织学分级、淋巴结转移及临床分期呈负相关性(P0.05);与患者年龄无关(P0.05)。c-Abl阳性率及WAVE2强阳性率均与乳腺癌的组织学分级、淋巴结转移及临床分期呈负相关性(P0.05);与患者年龄及肿瘤大小无关(P0.05)。3.Abi1蛋白表达与c-Abl和WAVE2蛋白表达呈正相关(P0.05)。结论乳腺癌中Abi1低表达与预后不良有关。乳腺癌中Abi1蛋白表达的变化可影响c-Abl蛋白的定位和WAVE2蛋白的表达。推测Abi1在Abl/Abi1/WAVE2通路中具有至关重要的地位。     

UCH-L1在乳腺癌中的表达及其与转移关系的研究

目的研究泛素羧基末端水解酶L1(UCH-L1)与磷酸化p38(p-p38)在乳腺癌组织、细胞系中的表达情况、两种蛋白的表达与临床病理特征的关系以及UCH-L1与乳腺癌侵袭转移的关系。方法用免疫组织化学方法检测乳腺癌组织中UCH-L1与p-p38蛋白的表达情况,用Western Blot方法检测乳腺癌组织以及细胞系中UCH-L1与p-p38蛋白的表达情况。应用UCH-L1特异性抑制剂作用于乳腺癌高侵袭高转移细胞系MDA-MB-435s后,用Western Blot观察UCH-L1与p-p38蛋白表达改变的情况,用Transwell实验检测MDA-MB-435s细胞侵袭潜能的改变。结果 UCH-L1和p-p38蛋白在乳腺浸润性导管癌中的表达高于其在癌旁正常乳腺组织中的表达(P=0.012,P=0.001),二者呈正相关(r=0.397,P=0.000),并与乳腺癌的TNM分期(P=0.017,P=0.010)、淋巴结转移情况(P=0.033,P=0.021)相关。乳腺上皮细胞系MCF-10A、乳腺癌低侵袭低转移细胞系MCF-7和乳腺癌高侵袭高转移细胞系MDA-MB-435s中两种蛋白表达水平呈递增趋势(P均<0.05)。UCH-L1特异性抑制剂可以浓度依赖性地下调MDA-MB-435s细胞系中p-p38蛋白的表达水平(P均<0.05),并能抑制乳腺癌细胞的侵袭转移潜能。结论 UCH-L1、p-p38过表达与乳腺癌的TMN分期、淋巴结转移有关。UCH-L1可能通过上调p-p38介导乳腺癌转移。     

NF2基因甲基化及其mRNA表达与乳腺癌发病的关系(英文)

目的:探讨乳腺癌中NF2基因启动子甲基化状态及其mRNA水平与乳腺癌发病的关系。方法:应用甲基化特异性聚合酶链反应(MSP)和逆转录-聚合酶链反应(RT-PCR)技术,检测47例乳腺癌组织及相应的癌旁组织和15例乳腺良性病变组织,分析NF2基因的甲基化与某些临床参数及mRNA表达的关系。结果:NF2基因启动子区在乳腺癌、癌旁和乳腺良性病变组织中的甲基化频率分别为57.4%(27/47)、23.4%(23/47)和0%(0/15),且乳腺癌组明显高于其余两组(P<0.05)。NF2基因发生甲基化与发病年龄、组织分型、转移和组织分级无相关性。乳腺癌组NF2基因mRNA的相对表达量(0.16±0.11)明显低于相应的癌旁组(0.27±0.14)及乳腺良性病变组(0.64±0.17()P<0.05)。NF2基因启动子区甲基化频率与其mRNA表达呈负相关(Spearman’sr=-0.314,P<0.05)。结论:NF2基因发生甲基化与乳腺癌的发生密切相关,NF2mRNA表达与NF2基因启动子高甲基化呈负相关。     

PIWIL4在人卵巢癌中的表达及其功能研究

采用半定量RT-PCR方法检测人卵巢透明细胞癌ES-2细胞中PIWIL1、PIWIL2、PIWIL3、PIWIL4 mRNA表达水平,以及PIWIL4在卵巢癌组织和癌旁正常组织中的表达情况．设计并化学合成针对PIWIL4的siRNA,用脂质体转染法将其转入ES-2细胞内,通过MTT和克隆形成实验,观察PIWIL4-siRNA对ES-2细胞生长活性和增殖能力的影响．半定量RT-PCR实验结果发现,ES-2细胞中,PIWIL4相对PIWIL1、PIWIL2、PIWIL3,其表达水平最高(P < 0.05),而且PIWIL4在卵巢癌组织中的表达明显高于癌旁正常组织(P < 0.01)．MTT实验和克隆形成实验结果显示,转染PIWIL4-siRNA的ES-2细胞生长活性和克隆形成率明显低于对照组(P < 0.05)．由此得出结论：PIWIL4在卵巢癌细胞系ES-2细胞表达较高,且它在卵巢癌组织中的表达明显上调,同时PIWIL4-siRNA可有效抑制ES-2细胞的生长活性和增殖能力,提示PIWIL4可能与卵巢癌发生、发展相关．     

FGFR4 mRNA及蛋白在乳腺癌组织中的表达及临床意义

目的:研究乳腺癌组织与乳腺癌癌旁组织中FGFR4 mRNA及蛋白的表达及其临床意义。方法:分别以实时荧光定量RT-PCR、Western blot的方法检测52例乳腺癌组织和52例癌旁正常组织中FGFR4 mRNA和蛋白的表达,分析FGFR4 mRNA和蛋白的表达与临床病理特征的相关性。结果:在乳腺癌组织中,FGFR4 mRNA及蛋白的表达均高于在乳腺癌癌旁正常组织(P0.05),并且FGFR4的表达与患者淋巴结转移和Her-2相关,而与患者年龄、肿瘤大小、分化程度、ER和PR无明显相关性(P0.05)。结论:FGFR4 mRNA及蛋白在乳腺癌组织中表达升高,与淋巴结转移和Her-2有关,有望成为预测乳腺癌的转移和预后的参考指标之一。     

SIAH ubiquitin ligases regulate breast cancer cell migration and invasion independent of the oxygen status

Seven-in-absentia homolog (SIAH) proteins are evolutionary conserved RING type E3 ubiquitin ligases responsible for the degradation of key molecules regulating DNA damage response, hypoxic adaptation, apoptosis, angiogenesis, and cell proliferation. Many studies suggest a tumorigenic role for SIAH2. In breast cancer patients SIAH2 expression levels correlate with cancer aggressiveness and overall patient survival. In addition, SIAH inhibition reduced metastasis in melanoma. The role of SIAH1 in breast cancer is still ambiguous; both tumorigenic and tumor suppressive functions have been reported. Other studies categorized SIAH ligases as either pro- or antimigratory, while the significance for metastasis is largely unknown. Here, we re-evaluated the effects of SIAH1 and SIAH2 depletion in breast cancer cell lines, focusing on migration and invasion. We successfully knocked down SIAH1 and SIAH2 in several breast cancer cell lines. In luminal type MCF7 cells, this led to stabilization of the SIAH substrate Prolyl Hydroxylase Domain protein 3 (PHD3) and reduced Hypoxia-Inducible Factor 1α (HIF1α) protein levels. Both the knockdown of SIAH1 or SIAH2 led to increased apoptosis and reduced proliferation, with comparable effects. These results point to a tumor promoting role for SIAH1 in breast cancer similar to SIAH2. In addition, depletion of SIAH1 or SIAH2 also led to decreased cell migration and invasion in breast cancer cells. SIAH knockdown also controlled microtubule dynamics by markedly decreasing the protein levels of stathmin, most likely via p27^Kip1. Collectively, these results suggest that both SIAH ligases promote a migratory cancer cell phenotype and could contribute to metastasis in breast cancer.     

miR-335 Targets SIAH2 and Confers Sensitivity to Anti-Cancer Drugs by Increasing the Expression of HDAC3

We previously reported the role of histone deacetylase 3 (HDAC3) in response to anti-cancer drugs. The decreased expression of HDAC3 in anti-cancer drug-resistant cancer cell line is responsible for the resistance to anti-cancer drugs. In this study, we investigated molecular mechanisms associated with regulation of HDAC3 expression. MG132, an inhibitor of proteasomal degradation, induced the expression of HDAC3 in various anti-cancer drug-resistant cancer cell lines. Ubiquitination of HDAC3 was observed in various anti-cancer drug-resistant cancer cell lines. HDAC3 showed an interaction with SIAH2, an ubiquitin E3 ligase, that has increased expression in various anti-cancer drug-resistant cancer cell lines. miRNA array analysis showed the decreased expression of miR-335 in these cells. Targetscan analysis predicted the binding of miR-335 to the 3′-UTR of SIAH2. miR-335-mediated increased sensitivity to anti-cancer drugs was associated with its effect on HDAC3 and SIAH2 expression. miR-335 exerted apoptotic effects and inhibited ubiquitination of HDAC3 in anti-cancer drug-resistant cancer cell lines. miR-335 negatively regulated the invasion, migration, and growth rate of cancer cells. The mouse xenograft model showed that miR-335 negatively regulated the tumorigenic potential of cancer cells. The down-regulation of SIAH2 conferred sensitivity to anti-cancer drugs. The results of the study indicated that the miR-335/SIAH2/HDAC3 axis regulates the response to anti-cancer drugs.     

SIAH1介导TRB3的泛素化和降解

目的利用酵母回转实验和免疫共沉淀实验验证SIAHI和TRB3之间的相互作用并探讨其功能相关性。方法将全长形式的TRB3基因和SIAH1基因分别克隆入酵母表达载体pDBLeu和pPC86中,共转化至MaV203酵母感受态细胞,验证其相互作用,然后分别构建至真核表达载体pCMV—Myc和pFLAG—CMV-2中,采用免疫共沉淀实验进行进一步验证。通过体内泛素化实验检测SIAH1对TRB3蛋白稳定性及泛素化修饰的影响。结果通过在酵母细胞中的回转实验和HEK293rr细胞中的免疫共沉淀实验证实了TRB3与SIAH1之间的相互作用。通过体内泛素化实验证实了S1AH1介导了TRB3的泛素化修饰和降解。结论证实了TRB3与SIAH1之间的相互作用并发现SIAH1介导了TRB3的泛素化修饰和降解,为TRB3蛋白的功能研究提供了新的线索。     

Monoubiquitylation of alpha-synuclein by seven in absentia homolog (SIAH) promotes its aggregation in dopaminergic cells

alpha-Synuclein plays a major role in Parkinson disease. Unraveling the mechanisms of alpha-synuclein aggregation is essential to understand the formation of Lewy bodies and their involvement in dopaminergic cell death. alpha-Synuclein is ubiquitylated in Lewy bodies, but the role of alpha-synuclein ubiquitylation has been mysterious. We now report that the ubiquitin-protein isopeptide ligase seven in absentia homolog (SIAH) directly interacts with and monoubiquitylates alpha-synuclein and promotes its aggregation in vitro and in vivo, which is toxic to cells. Mass spectrometry analysis demonstrates that SIAH monoubiquitylates alpha-synuclein at lysines 12, 21, and 23, which were previously shown to be ubiquitylated in Lewy bodies. SIAH ubiquitylates lysines 10, 34, 43, and 96 as well. Suppression of SIAH expression by short hairpin RNA to SIAH-1 and SIAH-2 abolished alpha-synuclein monoubiquitylation in dopaminergic cells, indicating that endogenous SIAH ubiquitylates alpha-synuclein. Moreover, SIAH co-immunoprecipitated with alpha-synuclein from brain extracts. Inhibition of proteasomal, lysosomal, and autophagic pathways, as well as overexpression of a ubiquitin mutant less prone to deubiquitylation, G76A, increased monoubiquitylation of alpha-synuclein by SIAH. Monoubiquitylation increased the aggregation of alpha-synuclein in vitro. At the electron microscopy level, monoubiquitylated alpha-synuclein promoted the formation of massive amounts of amorphous aggregates. Monoubiquitylation also increased alpha-synuclein aggregation in vivo as observed by increased formation of alpha-synuclein inclusion bodies within dopaminergic cells. These inclusions are toxic to cells, and their formation was prevented when endogenous SIAH expression was suppressed. Our data suggest that monoubiquitylation represents a possible trigger event for alpha-synuclein aggregation and Lewy body formation.     

The Expression of the Ubiquitin Ligase SIAH2 (Seven In Absentia Homolog 2) Is Increased in Human Lung Cancer

Objectives

Lung cancer is the leading cause of cancer-related deaths worldwide. Overall 5-year survival has shown little improvement over the last decades. Seven in absentia homolog (SIAH) proteins are E3 ubiquitin ligases that mediate proteasomal protein degradation by poly-ubiquitination. Even though SIAH proteins play a key role in several biological processes, their role in human cancer remains controversial. The aim of the study was to document SIAH2 expression pattern at different levels (mRNA, protein level and immunohistochemistry) in human non-small cell lung cancer (NSCLC) samples compared to surrounding healthy tissue from the same patient, and to analyse the association with clinicopathological features.

Materials and Methods

One hundred and fifty-two samples from a patient cohort treated surgically for primary lung cancer were obtained for the study. Genic and protein expression levels of SIAH2 were analysed and compared with clinic-pathologic variables.

Results

The present study is the first to analyze the SIAH2 expression pattern at different levels (RNA, protein expression and immunohistochemistry) in non-small cell lung cancer (NSCLC). We found that SIAH2 protein expression is significantly enhanced in human lung adenocarcinoma (ADC) and squamous cell lung cancer (SCC). Paradoxically, non-significant changes at RNA level were found, suggesting a post-traductional regulatory mechanism. More importantly, an increased correlation between SIAH2 expression and tumor grade was detected, suggesting that this protein could be used as a prognostic biomarker to predict lung cancer progression. Likewise, SIAH2 protein expression showed a strong positive correlation with fluorodeoxyglucose (2-deoxy-2(¹⁸F)fluoro-D-glucose) uptake in primary NSCLC, which may assist clinicians in stratifying patients at increased overall risk of poor survival. Additionally, we described an inverse correlation between the expression of SIAH2 and the levels of one of its substrates, the serine/threonine kinase DYRK2.

Conclusions

Our results provide insight into the potential use of SIAH2 as a novel target for lung cancer treatment.     

Regulation of Sprouty2 stability by mammalian Seven-in-Absentia homolog 2

Mammalian Sprouty (Spry) gene expression is rapidly induced upon activation of the FGF receptor signaling pathway in multiple cell types including cells of mesenchymal and epithelial origin. Spry2 inhibits FGF-dependent ERK activation and thus Spry acts as a feedback inhibitor of FGF-mediated proliferation. In addition, Spry2 interacts with the ring-finger-containing E3 ubiquitin ligase, c-Cbl, in a manner that is dependent upon phosphorylation of Tyr55 of Spry2. This interaction results in the poly-ubiquitination and subsequent degradation of Spry2 by the proteasome. Here, we describe the identification of another E3 ubiquitin ligase, human Seven-in-Absentia homolog-2 (SIAH2), as a Spry2 interacting protein. We show by yeast two-hybrid analysis that the N-terminal domain of Spry2 and the ring finger domain of SIAH2 mediated this interaction. Co-expression of SIAH2 resulted in proteasomal degradation of Spry1, 2, and to a lesser extent Spry4. The related E3 ubiquitin-ligase, SIAH1, had little effect on Spry2 protein stability when co-expressed. Unlike c-Cbl-mediated degradation of Spry2, SIAH2-mediated degradation was independent of phosphorylation of Spry2 on Tyr55. Spry2 was also phosphorylated on Tyr227, and phosphorylation of this residue was also dispensable for SIAH2-mediated degradation of Spry2. Finally, co-expression of SIAH2 with Spry2 resulted in a rescue of FGF2-mediated ERK phosphorylation. These data suggest a novel mechanism whereby Spry2 stability is regulated in a manner that is independent of tyrosine phosphorylation, and provides an addition level of control of Spry2 protein levels.     

Growth factor TGF-β induces intestinal epithelial cell (IEC-6) differentiation: miR-146b as a regulatory component in the negative feedback loop

TGF-β is a potent pleiotropic factor that promotes small intestinal cell differentiation. The role of microRNAs in the TGF-β induction of intestinal epithelial phenotype is largely unknown. We hypothesized that microRNAs are functionally involved in TGF-β-induced intestinal cell growth. In this study, TGF-β caused a morphological change of IEC-6 cells and stimulated expression of the epithelial cell markers alkaline phosphatase, villin, and aminopeptidase N. By global microRNA profiling during TGF-β-induced intestinal crypt cell (IEC-6) differentiation, we identified 19 differentially expressed microRNAs. We showed by real-time Q-PCR that miR-146b expression increased rapidly after TGF-β treatment; sequence analysis and in vitro assays revealed that miR-146b targets SIAH2, an E3 ubiquitin ligase, with decreased protein expression upon IEC-6 cell differentiation. Transfection of miR-146b inhibitor before TGF-β treatment blocked the down-regulation of SIAH2 in response to TGF-β. Moreover, SIAH2 over-expression during TGF-β treatment caused a significant decrease in Smad7 protein expression in IEC-6 cells. Furthermore, activation of the ERK1/2 pathway is active in the up-regulation of miR-146b by TGF-β. These findings suggest a novel mechanism whereby TGF-β signaling during IEC-6 cell differentiation may be modulated in part by microRNAs, and we propose a key role for miR-146b in the homeostasis of growth factor TGF-β signaling through a negative feedback regulation involving down-regulation of SIAH2 repressed Smad7 activities.     

福莫特罗对大鼠骨髓间充质干细胞向成骨细胞分化基因表达的影响

目的：研究β2肾上腺素能激动剂福莫特罗（Formoterol）对大鼠的体外骨髓间充质干细胞（MMSC）向成骨细胞分化的影响,进而探讨其作用机制。方法：取SD大鼠的骨髓间充质干细胞,用条件培养液诱导分化后分别加入不同浓度药物,在不同时间点采用RT-PCR法检测细胞分化中Runx2和Osterix的mRNA的表达,采用westernblot法检测细胞中MEK和ERK1/2的磷酸化。结果：在细胞分化早期,加入已知浓度10-7mol/L的Formoterol可抑制成骨样细胞细胞特异性转录因子Runx2mRNA表达;在细胞分化晚期,浓度10-7mol/L的Formoterol也可抑制成骨样细胞OsterixmRNA表达。在加入浓度10-7mol/的Formoterol作用30min后,MEK和ERK1/2的蛋白磷酸化表达均下降。结论：β2受体激动剂可抑制MMSC细胞体外向成骨样细胞的分化,并且可抑制MEK和ERK1/2磷酸化的表达。