内源性CaN蛋白抑制剂RCAN1在肿瘤中的作用

研究表明CaN通过调节底物蛋白NFAT激活多条细胞内信号转导通路、参与多种病理生理过程。近些年有研究报道CaN-NFAT通路也参与了肿瘤的增殖、侵袭与转移。发现CaN与肺癌嗜骨转移相关。由于外源性抑制剂对各器官组织无选择性及全身应用的毒性,限制了其应用;RCANs是一类具有高效专一低毒特点的内源CaN抑制剂,基于RCANs参与CaN/NFAT通路对CaN抑制的基础之上研究了RCAN1在神经疾病、肌萎缩、血管、免疫抑制及肿瘤中的作用。本文就CaN、NFAT、RCAN1分子结构、相互作用机制及RCAN1-CaN-NFAT通路在肿瘤中的相关研究做一综述,为寻找新的肿瘤治疗方法及药物开辟新的途径。     

CaN／NFAT信号通路与肺癌骨转移的关系

CaN／NFAT信号通路在免疫系统、神经系统和心血管系统中的作用目前比较清楚。近期研究发现此信号通路具有致癌的潜能：对肿瘤细胞、破骨细胞和成骨细胞均有影响,而肿瘤骨转移的发生是这三种细胞相互作用的结果。因此,CaN／NFAT信号通路可能在恶性肿瘤骨转移的发生中发挥重要作用。     

CaN/NFAT信号通路与肺癌骨转移的关系

CaN/NFAT信号通路在免疫系统、神经系统和心血管系统中的作用目前比较清楚.近期研究发现此信号通路具有致癌的潜能:对肿瘤细胞、破骨细胞和成骨细胞均有影响,而肿瘤骨转移的发生是这三种细胞相互作用的结果.因此,CaN/NFAT信号通路可能在恶性肿瘤骨转移的发生中发挥重要作用.     

BDNF对全脑放疗后NFAT3/c4介导的信号通路相关因子作用研究

目的 观察不同剂量电离辐射对NFAT3/c4信号通路表达的影响以及外源性的BDNF对该通路的改善作用。方法 选用1个月龄SD大鼠分成4个组分别接受单次0、2、10、20 Gy照射,照后3 d进行双侧海马立体定向注射外源性的BDNF。后取脑部海马组织进行蛋白印迹法及PCR技术观察NFAT3/c4相关蛋白表达情况。结果 蛋白印迹法及PCR结果表明电离辐射后NFAT3/c4的表达水平明显下降并呈剂量及时间依赖性。IR+BDNF组较单纯照射组相比,随着照射剂量增加及时间延长NFAT3/c4和CaN表达水平明显升高。结论 全脑放疗抑制了CaN/NFAT3/c4信号通路,外源性BDNF能促进NFAT依赖的转录,从而改善认知功能的下降。     

基于Oncomine和GEO数据库分析RCAN1基因在乳腺癌中的表达及临床意义

目的:探讨钙调磷酸酶调节因子1(regulator of calcineurin 1,RCAN1)基因在乳腺癌中的表达及临床意义。方法:检索Oncomine和GEO数据库中有关RCAN1的信息,并对所获取的数据资料挖掘并进行二次分析,对RCAN1在乳腺癌中的作用进行荟萃分析。结果:Oncomine数据库中共收集了454项不同类型RCAN1的研究结果,关于在肿瘤与对照组织中RCAN1表达有统计学差异的结果有64项,其中RCAN1表达增高的有20项,表达降低的有44项。涉及到乳腺癌的研究数据集共有13项。乳腺癌中高表达的研究有0项、低表达的有13项。共有6项研究,9个乳腺癌分型数据集涉及RCAN1在乳腺癌组织和正常组织中的表达,包括2 508例样本。在数据库中综合比较9项研究成果,发现与正常组织相比,RCAN1在乳腺癌中的表达量低于正常组织（P<0.05）。不仅如此,通过挖掘GEO数据库,发现低表达RCAN1的患者总体死亡率较高,高表达RCAN1的患者预后较好（P<0.05）。结论:通过深入挖掘Oncomine和GEO基因芯片数据库中肿瘤相关的基因信息,提示RCAN1的mRNA水平在乳腺癌组织中呈现低表达,并与乳腺癌预后相关,有望成为抗乳腺癌靶向治疗药物的重要靶点。     

活化T细胞核因子与肿瘤发生和发展的研究进展

活化T细胞核因子(nuclear factor of activated T cells,NFAT)是一组在哺乳动物细胞内广泛表达的转录因子,主要参与精密调控机体生长发育相关的、复杂的细胞内相互作用。近年来,越来越多的研究数据显示NFAT与人类肿瘤的发生、发展密切相关在多种肿瘤细胞及肿瘤微环境的复杂间质成分中,NFAT异常活化,促进肿瘤形成和浸润转移。本文旨在阐述目前研究发现的NFAT在肿瘤生物学中发挥的重要作用,涉及肿瘤的形成、生长、存活、恶性转化、侵袭转移和血管生成等过程,以及NFAT在肿瘤发生、发展中的作用机制,预测这些研究结果对于开辟新的肿瘤治疗途径有着重要的意义。     

RCAN1在恶性肿瘤中的研究进展

钙调神经磷酸酶调节蛋白(Regulator of calcineurin 1,RCAN1)作为与钙调神经磷酸酶(Calcineurin,CaN)发生相互作用的内源性蛋白,在许多恶性肿瘤细胞中广泛表达,如小细胞肺癌、甲状腺癌、白血病、肝癌、恶性胶质细胞瘤、子宫内膜腺癌等。近年来研究显示,当RCAN1呈高表达状态时,可以通过多种途径来抑制肿瘤的增殖、分化、侵袭和转移,从而抑制肿瘤的进展。这些研究结果对患者的生存期和预后评估有着重要的指导作用,并对恶性肿瘤的治疗和干预奠定了一定的理论基础。     

CaN/NFATc1通路与骨癌痛发生机制的研究进展

骨癌痛（cancer induced bone pain，CIBP）是由原发性或转移性骨肿瘤及抗癌治疗或合并症如关节炎、痛风、脊椎关节强直等引起的骨疼痛，是中晚期癌症常见的症状之一，目前多以局部放疗、双磷酸盐及三阶梯镇痛处理, 但尚缺乏更精准的靶向治疗方法。研究表明，钙调神经磷酸酶（Calcineurin，CaN）/活化T细胞核因子（Nuclear factor-activated T cell，NFAT）通路与骨吸收重建及骨微环境的改变密切相关，尤其是NFATc1作为OPG-RANK-RANKL系统下游的信号分子，其对破骨细胞的分化发挥着重要的转录调节作用，分化后的破骨细胞可实现骨吸收导致骨密度 降低，破坏骨结构，引起CIBP。本文就破骨细胞中CaN/NFATc1通路与CIBP发生机制的研究进展进行简要综述，为今后骨癌痛的治疗提供新的思路。     

PD-1/PD-L1抑制剂在淋巴瘤治疗中的研究进展

近年来,肿瘤生物免疫治疗因其显著的疗效而迅速发展为肿瘤研究领域的热点。程序性死亡受体-1（programmed death-1,PD-1）与其配体（programmed death ligand-1,PD-L1）在多种肿瘤细胞中过表达,参与肿瘤的发生、发展及侵袭转移。因此,PD-1/PDL1信号通路成为了肿瘤免疫治疗的有效新靶点。目前,PD-1/PD-L1抑制剂在淋巴瘤治疗研究中取得了较好的疗效。本文将对该类药物的相关临床研究现状进行综述,旨在加深对PD-1/PD-L1信号通路的作用机制及相关抗体应用于淋巴瘤治疗的认识。      

MEKK1在肿瘤MAPK信号传导通路中作用的研究进展

目的:总结国内外关于MEKK1在肿瘤MAPK信号通路中的调控作用,及其对肿瘤转移、细胞迁移和运动影响的研究进展.方法:应用Medline及CNKI期刊全文数据库检索系统,以"MEKK1、MAPK信号转导和肿瘤"为关键词,检索1992-01-2008-01的相关文献,共检索到英文文献4046篇和中文文献2篇.纳入标准:1)MEKK1的来源和分子结构特征;2)MEKK1与肿瘤相关的MAPK信号通路及其他信号通路的关系;3)MEKK1与AP1的关系;4)MEKK1与肿瘤细胞凋亡的关系;5)MEKK1与肿瘤细胞迁移和运动的关系.根据纳入标准,精选55篇文献,最后纳入分析21篇文献.结果:MEKK1是MAPK信号传导通路中的重要结点,也是MAPK通路与其他信号通路的结点.MEKK1具有广泛的生物学功能,如调控NFκB和AP1,影响细胞的存活和凋亡,并且与肿瘤细胞的侵袭、迁移和运动密切相关.结论:MEKK1是抗肿瘤药物研究的潜在靶点,虽然目前还没有MEKK1的抑制剂上市,但可通过研究疾病状态下与MEKK1过表达有关的细胞功能来开发MEKK1抑制剂.     

钙调神经磷酸酶CaNAαa和CaNAβ在肺癌中的表达及意义

目的：检测钙调神经磷酸酶（calcineurin,CaN）Aα和Aβ亚基蛋白在肺癌细胞中的表达,研究CaN蛋白亚基的表达与肺癌骨转移发生是否相关。方法：应用PCR和Westernblot方法检测SBC-5、SBC-3和NCI—H345小细胞肺癌细胞中CaNAα和Aβ在基因和蛋白水平上的表达;通过免疫组织化学方法检测肺癌骨转移和肺癌无骨转移患者肺癌组织中CaNAα和Aβ的表达。结果：CaNAα和Aβ的表达强度在能产生骨转移的肺癌细胞SBC-5中明显高于非骨转移肺癌细胞SBC-3和NCI—H345。在肺癌伴有骨转移患者的肺癌组织中CaNAα和CaNAβ的表达强度也都明显较无骨转移肺癌患者组高（CaNAαP=n000;CaNAβP=n030）。结论：钙调神经磷酸酶不同亚基（CaNAα和Aβ）的表达可能在肺癌骨转移的发生和发展中具有重要意义。     

Calcineurin-mediated dephosphorylation of c-Jun Ser-243 is required for c-Jun protein stability and cell transformation

The proto-oncogene c-Jun plays an important role in regulating tumor progression. We previously reported that the serine/threonine phosphatase calcineurin (CaN, also called PP2B) dephosphorylates the C-terminus (Ser-243) of c-Jun, resulting in the increase in c-Jun and Sp1 interaction, and subsequent c-Jun-induced gene expression. Here, we demonstrate the interaction of c-Jun and CaN in the nucleus of living cells by fluorescence resonance energy transfer assay and that this interaction is mediated through the calmodulin-binding domain of CaN. Furthermore, c-Jun protein stability was altered by CaN-mediated dephosphorylation at the Ser-243 site of c-Jun. The half-life of the c-Jun mutant, c-Jun-S243A was longer than that of the wild-type c-Jun. Moreover, silencing of endogenous CaN expression led to increased c-Jun ubiquitination and decreased stability. In 46% of clinical cervical tissue samples obtained from patients with cervical cancer, enhanced c-Jun and CaN expression, as well as decreased phospho-Ser-243 expression levels were detected. Our results suggest that CaN stabilizes c-Jun by dephosphorylating c-Jun at Ser-243 to enhance its tumorigenic ability.     

Immunocytochemical detection of calcineurin and microtubule-associated protein 2 in central neurocytoma

Summary An immunohistochemical study was carried out on four cases of central neurocytoma, which had characteristic clinicopathological features including ultrastructural findings. Specific antibodies to calcineurin (CaN), microtubule-associated protein 2 (MAP2) and synaptophysin (SYP) were used. All tumor tissues examined showed specific immunoreactivity for CaN and MAP2. Immunolabelling of both molecules revealed that they were mainly localized in the perikarya and proximal processes of the tumor cells. SYP immunoreactivity was found in three of the four cases. SYP immunoreaction products were predominantly seen in the tumor cell processes, while the perikarya were weakly or moderately positive for SYP. The data suggest that CaN and MAP2, together with SYP, can be useful tools for identifying and characterizing of the central neurocytoma.     

PET/MRI在高级别脑胶质瘤放射治疗中的应用

脑胶质瘤是最常见的原发性神经系统肿瘤,其中高级别胶质瘤生长迅速,常呈浸润性生长,且治疗后易复发,死亡率和致残率都很高。手术切除仍是高级别胶质瘤的首选治疗方法,术后放射治疗则是其重要的辅助治疗手段之一。目前放射治疗多以MRI图像指导靶区的勾画,但MRI在肿瘤显像方面仍存在局限性。随着多种放射性示踪剂的研究及应用,PET能够通过肿瘤组织的代谢变化来反映肿瘤的浸润范围,还有助于鉴别放射性坏死与肿瘤复发。PET/MRI的联合应用在高级别脑胶质瘤的放射治疗中具有很好的应用前景。     

Immunosuppressant inhibition of P-glycoprotein function is independent of drug-induced suppression of peptide-prolyl isomerase and calcineurin activity

Purpose: P-glycoprotein is a 170-kDa plasma membrane multidrug transporter that actively exports cytotoxic substances from cells. Overexpression of P-glycoprotein by tumor cells is associated with a multidrug-resistant phenotype. Immunosuppressive agents such as cyclosporins and macrolides, have been shown to attenuate P-glycoprotein activity. However, the mechanism by which some immunosuppressants inhibit P-glycoprotein function has not been determined. Since cyclosporin and macrolide immunosuppressants inhibit calcineurin (CaN) phosphatase and FKBP12 peptide-prolyl isomerase (FKBP12 PPI) activity, studies were conducted to determine if these effects are directly related to the inhibitory effects these immunosuppressants have on P-glycoprotein function. Methods: Western blot analysis was performed to assess CaN and FKBP12 protein levels in P-glycoprotein-negative (MCF-7) and -positive (MCF-7/Adr) breast cancer cell lines. P-glycoprotein function was determined by intracellular doxorubicin accumulation and/or cytotoxicity assays before and after CaN and FKBP12 were independently inhibited by pharmacological antagonists. Results: CaN and FKBP12 levels were similar in MCF-7 and MCF-7/Adr cells. P-glycoprotein function was not affected by treatment of P-glycoprotein-expressing MCF-7/Adr cells with CaN and FKBP12 antagonists. Conclusions: These results demonstrate that the inhibitory effects of immunosuppressive agents on P-glycoprotein function are independent of CaN or FKBP12 PPI activity. Received: 1 July 1998 / Accepted: 16 December 1998     

肺癌骨转移患者CaN、PTHRP的水平变化及诊断价值探讨

目的 探讨血清钙调磷酸酶(CaN)和甲状旁腺激素相关蛋白(PTHRP)对早期诊断肺癌骨转移的临床价值.方法 选取79例肺癌骨转移患者(转移组)和90例肺癌未发生骨转移患者(无转移组),检测两组患者的血清CaN、PTHRP、癌胚抗原(CEA)、CA125、骨碱性磷酸酶(BALP)的水平并进行比较分析.结果 转移组患者的血清CaN、PTHRP、CEA、CA125、BALP水平明显高于无转移组,差异有统计学意义(P﹤0.01).转移组患者的血清CaN、PTHRP与CEA、CA125、BALP水平均呈明显正相关(P﹤0.01).绘制ROC曲线,当选取CaN=590.4 U/ml为诊断临界点时,鉴别诊断肺癌骨转移的灵敏度为78.2%,特异度为84.0%,漏诊率为21.8%,误诊率为16.0%, ROC曲线下面积为0.872(95%CI:0.821~0.946);当选取PTHRP=6.81 ng/ml为诊断临界点时,鉴别诊断肺癌骨转移的灵敏度为70.4%,特异度为78.5%,漏诊率为29.6%,误诊率为21.5%,ROC曲线下面积为0.811(95%CI:0.785~0.863).结论 肺癌骨转移患者的血清CaN和PTHRP水平升高明显,对肺癌骨转移有一定的鉴别诊断价值.     

Overexpression of calcineurin B subunit (CnB) enhances the oncogenic potential of HEK293 cells

Calcineurin (CaN) is a Ca²⁺/calmodulin (CaM)-stimulated protein phosphatase. It is a heterodimeric enzyme consisting of a catalytic A subunit (CnA) and a Ca²⁺-binding regulatory B subunit (CnB). CaN's key role in vivo is well known, while the function of CnB keeps unclear except that it acts as a regulator of CaN. The present paper shows that CnB overexpression promotes proliferation of human embryonic kidney HEK293 cells by comparing with vector control cells in the complete or serum reduced medium. Furthermore, stable CnB transfectants showed dramatically improved growth in soft agar. And the migration ability of CnB overexpressors also was enhanced remarkably. But in the progress of transformation, the activity of CaN remained unchanged between CnB overexpressors and controls. Therefore, CnB, rather than CaN, is involved in the proliferation promotion of HEK293 cells. Subsequently, 11 proteins with different expression levels between CnB transfectants and controls were identified using two-dimensional gel electrophoresis and electrospray ionization time-of-fight mass spectrometry. Therein, the expression of heat shock protein 27 (HSP27) and protein DJ-1 increased along with CnB overexpression. The important role of CnB in cell neoplastic transformation was found and the possible mechanism was analyzed. ( Cancer Sci 2008; 99: 1100–1108)