Wnt和相关信号通路交互作用在非小细胞肺癌发生发展中的作用

Wnt信号通路和相关信号通路(如EGFR,Notch,Hedgehog等信号通路)在肿瘤发生发展中起着重要的作用。研究证实,Wnt与EGFR及Notch通路的交互在肺癌中起重要作用,Wnt和Hedgehog信号通路交互在宫颈癌中起重要作用。本文主要就Wnt信号通路和EGFR,Notch,Hedgehog信号通路在非小细胞肺癌发生发展中的作用及其相互联系进行综述。     

Wnt拮抗因子SFRP1与肿瘤相关性的研究进展

Wnt信号通路是一类在物种进化过程中高度保守的信号通路,对细胞增殖、迁移、分化有重要影响,在胚胎发育、组织内平衡和肿瘤进展过程中扮演重要角色。分泌型卷曲相关蛋白1(SFRP1)是已知的Wnt信号通路拮抗剂,定位于人染色体8p11.2上,是近年来发现的新的抑癌基因。SFRP1基因在多种肿瘤中的缺失,导致Wnt信号通路转导途径紊乱,影响肿瘤的发生及发展。1 Wnt信号通路简介     

Wnt信号通路在神经和记忆以及精神疾病中的作用

Wnt信号通路是一种在进化中高度保守的信号通路,其各元件在个体发育过程中起重要作用。Wnt信号通路在成年神经系统的发育中起着关键作用,其参与了突触形成,神经传递以及突触可塑性的调节。Wnt信号通路的下调与神经退行性疾病及精神和情绪障碍性疾病有很大的关系。本文对近年来Wnt信号通路的研究、Wnt信号通路在记忆以及神经退行性疾病中的调控作用予以综述。     

肠癌细胞中Hedgehog信号通路改变对β-链接素表达影响作用研究

<正>Hedgehog信号通路是人类胚胎发育过程中调控细胞增殖和组织分化的重要信号通路。该信号通路异常表达与越来越多的肿瘤,如基底细胞癌、髓母细胞瘤、横纹肌肉瘤、小细胞肺癌、胰腺癌、食管癌等多种肿瘤的发病有关[1],但Hedgehog在大肠癌发病中的具体机制还不是很清楚。而Wnt信号通路是与大肠癌的发生发展密切相关的另一条信号通路,其中β-链接素(β-catenin)除了参与细胞间黏附外,也是Wnt信号通路的关键因子,其突变或表达异常可能参与肿瘤的发生及进展[2]。然而,在大肠癌中Hedgehog信号通路与Wnt信号通路之间的调控关系仍存在争议。本研究应用实时荧光定量-聚合酶链反应(RT-PCR)及蛋白印迹法检测激活Hedgehog信号通路后肠癌细胞系HCT116、HT29、DLD1、SW620中     

Wnt/β-catenin信号通路抑制剂的抗肿瘤研究进展

Wnt信号通路广泛存在于多细胞真核生物中,并且高度保守,在胚胎发育过程中起到重要作用。大量研究表明,Wnt信号通路的异常激活与肿瘤的发生发展密切相关,其在多种恶性肿瘤的增殖、分化、凋亡、迁移、侵袭、上皮间质转化(Epithelial-mesenchymal transition, EMT)及肿瘤干细胞特性中发挥重要作用,因此开发靶向Wnt信号通路的抗肿瘤药物具有重要意义。目前,Wnt信号通路抑制剂的研究已取得一定进展。本文主要对近年来Wnt途径中关键成员Wnt/β-catenin信号通路的抑制剂在肿瘤治疗中的研究进展作一综述。     

Wnt/β-catenin信号通路调控Sp5机制的研究进展

摘要：Wnt/β-catenin信号通路是一条广泛存在于生物体内且在进化上具有高度保守特性的通路。该通路在细 胞生长、发育、迁移及凋亡过程中发挥着重要作用。特异性蛋白-5（Sp5）作为Wnt/β-catenin信号通路的下游靶点,在 发育过程中也有着重要的调控作用,包括细胞分化、组织形成及肿瘤的发生等。本文就Wnt/β-catenin信号通路对其 下游分子Sp5的作用进行综述,明确Wnt/β-catenin-Sp5在疾病发展中的作用。     

Wnt通路在肿瘤中的作用及其相应抑制剂的研究进展

近些年研究表明,Wnt信号通路不仅在胚胎发育中起着重要的作用,还与肿瘤的发生关系甚密。本文将着重介绍Wnt信号通路的组成,分析它在各肿瘤发生中的作用机制及其相应抑制剂在治疗肿瘤中可能发挥的作用。     

Dvl交叉调控Wnt及NF-κB信号通路在类风湿性关节炎骨侵蚀中的作用研究进展

Wnt信号通路在骨细胞的成熟、分化和凋亡过程中具有重要的调控作用,通过调控成骨细胞和破骨细胞从而达到骨代谢的动态平衡。Wnt通路激活不足或过度激活均参与了类风湿性关节炎的发生和发展。核因子κB(NF-κB)是一种具有多向性调节作用的转录因子,参与细胞的生长、发育、凋亡等多种生理功能。如果NF-κB通路被不适当的活化,则可导致多种自身免疫和炎症性疾病,这其中就包括类风湿性关节炎。Dvl蛋白是Wnt信号通路中关键蛋白,有研究发现其也参与NF-κB通路的调控。因此,通过对Dvl蛋白交叉调控Wnt和NF-κB通路的研究,有可能为我们提供治疗类风湿关节炎新的药物靶点。     

Notch信号通路与乳腺癌的研究进展

Notch信号通路是一条进化过程中高度保守的信号通路,广泛存在于生物进化过程中,是决定细胞命运的重要通路之一,相邻细胞通过Notch受体与配体相互作用转导细胞信号,在细胞的增值、分化及凋亡过程中发挥重要的调控作用。Notch信号通路的异常激活与乳腺癌的发生、发展有着密切关系,本文对Notch信号通路及其异常表达与乳腺癌的关系进行综述,重点讲述Notch信号通路与乳腺癌的发病机制,希望能给靶向治疗乳腺癌带来一条新的思路。     

Wnt信号通路中糖原合成激酶3β和β-catenin在人脑胶质瘤中的表达及其意义

<正>胶质瘤是神经系统常见的恶性肿瘤,单纯手术切除预后较差,目前国内外学者都在寻找能够治疗胶质瘤新的靶向药物及新的肿瘤信号通路的分子抑制剂。近期研究发现Wnt通路中信号成分的改变在胶质瘤的发生过程中起着重要作用。本研究主要检测Wnt信号转导通路中糖原合成激酶2(GSK)3β和β-catenin在胶质瘤中的表达及其作用关系。希望找到     

选择性雌激素受体下调剂研究进展

乳腺癌作为全球女性发病率最高的癌症,一直威胁着全世界女性的健康。雌激素受体(estrogen receptor,ER)介导的信号通路在乳腺癌疾病发展中扮演着重要的角色,成为乳腺癌治疗的重要靶点之一,一直吸引着许多药企进行相关药物的研发。2002年,由阿斯利康开发的首个选择性雌激素受体下调剂(selective estrogen receptor down-regulators,SERDs)——氟维司群正式在美国上市。氟维司群通过下调ER水平,全面抑制ER信号通路,临床疗效优于其他内分泌治疗药物,使得SERDs受到越来越多药企的关注。然而,肌内注射限制了氟维司群的临床应用,表明SERDs的开发仍有很大提升空间。综述相关SERDs的研发现状,为进一步研究与应用提供参考。     

17-Beta-estradiol inhibits transforming growth factor-beta signaling and function in breast cancer cells via activation of extracellular signal-regulated kinase through the G protein-coupled receptor 30

Breast cancer development and breast cancer progression involves the deregulation of growth factors leading to uncontrolled cellular proliferation, invasion and metastasis. Transforming growth factor (TGF)-beta plays a crucial role in breast cancer because it has the potential to act as either a tumor suppressor or a pro-oncogenic chemokine. A cross-communication between the TGF-beta signaling network and estrogens has been postulated, which is important for breast tumorigenesis. Here, we provide evidence that inhibition of TGF-beta signaling is associated with a rapid estrogen-dependent nongenomic action. Moreover, we were able to demonstrate that estrogens disrupt the TGF-beta signaling network as well as TGF-beta functions in breast cancer cells via the G protein-coupled receptor 30 (GPR30). Silencing of GPR30 in MCF-7 cells completely reduced the ability of 17-beta-estradiol (E2) to inhibit the TGF-beta pathway. Likewise, in GPR30-deficient MDA-MB-231 breast cancer cells, E2 achieved the ability to suppress TGF-beta signaling only after transfection with GPR30-encoding plasmids. It is most interesting that the antiestrogen fulvestrant (ICI 182,780), which possesses agonistic activity at the GPR30, also diminished TGF-beta signaling. Further experiments attempted to characterize the molecular mechanism by which activated GPR30 inhibits the TGF-beta pathway. Our results indicate that GPR30 induces the stimulation of the mitogen-activated protein kinases (MAPKs), which interferes with the activation of Smad proteins. Inhibition of MAPK activity prevented the ability of E2 from suppressing TGF-beta signaling. These findings are of great clinical relevance, because down-regulation of TGF-beta signaling is associated with the development of breast cancer resistance in response to antiestrogens.     

Evidence that bone marrow-derived mesenchymal stem cells reduce epithelial permeability following phosgene-induced acute lung injury via activation of wnt3a protein-induced canonical wnt/β-catenin signaling

An increase in epithelial cell permeability has been proposed to contribute to phosgene-induced acute lung injury (ALI). However, no specific and effective means for blocking increases in permeability are currently available. Cell-based therapy using bone marrow-derived mesenchymal stem cells (MSCs) is an attractive new approach. Canonical wnt/β-catenin signaling has been demonstrated to contribute to both epithelial cell injury and repair mechanisms in ALI. The goal of our study was to determine the effects of MSCs on epithelial permeability in phosgene-induced ALI in Sprague–Dawley (SD) rats and identify changes in major components of the wnt3a/β-catenin signaling pathway during this process. Epithelial cell permeability was evaluated by measuring total protein, albumin, keratinocyte growth factor, and occludin in bronchoalveolar lavage fluid and lung tissue. MSCs-harboring lentiviral vectors expressing green fluorescent protein (GFP) were used to determine rates of MSC engraftment at injured sites. Lung tissue was excised to evaluate changes in the levels of proteins that function in wnt3a/β-catenin signaling, including wnt3a, total β-catenin, non-phosphorylated-Ser33/37/Thr41 β-catenin, axin2, and cyclin D1 by western blot analysis. Because TGF-β1 and wnt5a can inhibit canonical wnt/β-catenin signaling, we also measured levels of TGF-β1 and wnt5a by western blotting.

Conclusions: (1) TGF-β1 and wnt5a expression correlated with inhibition of wnt3a/β-catenin signaling in our phosgene-induced ALI model and (2) exogenously supplied MSCs homed to sites of lung injury and reduced epithelial permeability likely by blocking TGF-β1- and wnt5a-mediated inhibition of wnt3/β-catenin signaling.     

Interaction between estrogen receptor alpha and insulin/IGF signaling in breast cancer

Estrogens and insulin/Insulin like growth factor 1 (IGF-I) have potent positive effects on the proliferation of mammary epithelial cells and estrogen-dependent breast cancer cells. A cooperative crosstalk between estrogens and insulin/IGF-I signaling pathways exists and it plays a critical role in breast carcinogenesis, tumor cell proliferation, differentiation and survival through the modulation of multiple biological events. The biological effects of estrogens are mainly mediated by the activation of estrogen receptor (ERalpha) whose activity is deeply influenced by the insulin/IGF-I signaling pathway. On the other hand, estrogens enhance insulin signaling by increasing the expression and/or the functional activity of some proteins involved in the insulin/IGF-I pathway. This review will focus on the critical node of the IGF-I network involved in the crosstalk with ERalpha and implicated in breast cancer development and progression.     

Inhibition of insulin-like growth factor 1 receptor signaling enhanced silibinin-induced activation of death receptor and mitochondrial apoptotic pathways in human breast cancer MCF-7 cells

Silibinin, which had been used as a hepatoprotectant, was shown to have anticancer activity. In this study we investigated the mechanisms of silibinin-induced apoptosis in human breast cancer MCF-7 cells. Expressions of Fas ligand (FasL), Fas-associated death domain protein (FADD), and Bax were significantly up-regulated in silibinin-treated cells, whilst silibinin induced a conspicuous translocation of Bax to mitochondria and release of cytochrome c to the cytosol. Therefore, both the extrinsic Fas death receptor and intrinsic mitochondrial death pathways played essential roles in silibinin-induced apoptosis. It was also found that silibinin markedly decreased protein expression of SIRT1, a mammalian homologue of yeast Sir2, which was proved to have a role in sequestering Bax away from mitochondria. Insulin-like growth factor 1 receptor (IGF-1R), a receptor tyrosine kinase with a crucial role in malignancy development, is expressed in most human primary breast carcinomas. Our results showed that silibinin-induced apoptosis was significantly reinforced by blocking IGF-1R signaling with tyrphostin AG1024, a specific inhibitor of IGF-1R autophosphorylation. Up-regulation of FADD, down-regulation of SIRT1 expression, and activation of the mitochondrial death pathway were apparently enhanced by AG1024 in the silibinin-treated MCF-7 cells.     

Everolimus: targeted therapy on the horizon for the treatment of breast cancer

The mammalian target of rapamycin (mTOR) is a signaling kinase of the phosphatidylinositol 3-kinase/protein kinase B (also known as Akt) signaling pathway that mediates cell growth and metabolism. Dysregulation of the mTOR pathway creates a favorable environment for the development and progression of many cancers, including breast cancer, and is associated with the development of resistance to endocrine therapy and to the anti-human epidermal growth factor receptor-2 (HER2) monoclonal antibody trastuzumab. Therefore, the addition of mTOR inhibitors to conventional breast cancer therapy has the potential to enhance therapeutic efficacy and/or overcome innate or acquired resistance. Everolimus, an mTOR inhibitor with demonstrated preclinical activity against breast cancer cell lines, has been shown to reverse Akt-induced resistance to hormonal therapy and trastuzumab. Phase I-II clinical trials have demonstrated that everolimus has promising clinical activity in women with HER2-positive, HER2-negative, and estrogen receptor-positive breast cancer when combined with HER2-targeted therapy, cytotoxic chemotherapy, and hormonal therapy, respectively. Everolimus is generally well tolerated; hematologic abnormalities and stomatitis are most common adverse events when this drug is combined with cytotoxic chemotherapy. Based on these promising results, everolimus is currently under evaluation in a series of phase III Breast Cancer Trials of Oral Everolimus (BOLERO) trials of women with HER2-positive and estrogen receptor-positive breast cancer. Results of these trials will help to establish the role of everolimus in the treatment of clinically important breast cancer subtypes.     

关于紫杉类药物药理及临床研究

紫杉类药物是从植物紫杉中提取,而合成的一种中成药。主要药理是对于细胞的有丝分裂发挥作用,或者是通过其他的信号通路抑制肿瘤细胞,导致肿瘤细胞的凋亡。紫杉类药物作为抗癌药物已经被公认。紫杉类药物在卵巢癌、乳腺癌、肺癌等严重危害人类健康的肿瘤的治疗中发挥了极为重要的作用,在其他疾病的治疗,比如Ca2＋通道异常的疾病中也有一定的疗效。该药物在肿瘤治疗和其他疾病的治疗中有很大的发展潜力。     

p90核糖体S6激酶2——治疗三阴性乳腺癌的潜在靶标

三阴性乳腺癌是乳腺癌的一种特殊类型,由于高侵袭性、易复发、易转移等特点成为临床上的一大难题。p90核糖体S6激酶（RSK）是Ras-Raf-MEK-ERK信号通路下游的信号分子,其家族成员RSK2在三阴性乳腺癌中高表达,与肿瘤细胞的增殖、凋亡及侵袭密切相关,是治疗三阴性乳腺癌的具有潜力的靶标。综述了RSK2在癌症发生发展中的作用及其抑制剂的研究进展,旨在为三阴性乳腺癌靶向药物的研发提供思路与参考。