哺乳动物雷帕霉素靶向抑制剂靶向治疗肿瘤的进展

细胞生长受到复杂、精细的网络调控,哺乳动物雷帕霉素靶向(mammalian target of rapamycin,mTOR)在该调控系统中的作用尤为重要[1].     

哺乳动物雷帕霉素靶蛋白复合物在神经发生中的研究进展

神经发生过程失调可导致多种神经功能障碍,引起一系列的神经病症,如癫痫和自闭症等.哺乳动物雷帕霉素靶蛋白(mTOR)通过整合细胞内信号来控制细胞生长、营养代谢和蛋白质翻译,同时也参与调节大脑发育过程中神经元的增殖、分化、迁移和树突形成等.此外,mTOR在突触形成和可塑性方面也起着重要作用.多种神经系统发育的严重缺陷与mT...     

腺嘌呤核苷酸活化蛋白激酶与哺乳动物雷帕霉素靶蛋白信号转导通路的相互作用

背景：腺嘌呤核苷酸活化蛋白激酶的下游靶分子哺乳动物雷帕霉素靶蛋白对细胞生长、分裂和蛋白质合成有重要意义。 目的：综述腺嘌呤核苷酸活化蛋白激酶与哺乳动物雷帕霉素靶蛋白信号转导相互调节的最新研究进展,以期揭示腺嘌呤核苷酸活化蛋白激酶和哺乳动物雷帕霉素靶蛋白信号转导的交互作用对蛋白质合成的影响。 方法：以“(mammalian target of rapamycin OR mTOR) AND (AMP activated protein kinase OR AMPK) AND signal transduction”为检索式,计算机检索PubMed数据库相关内容的文献,最终纳入30篇可反映腺嘌呤核苷酸活化蛋白激酶与哺乳动物雷帕霉素靶蛋白信号转导通路相互作用的文献,并进行归纳总结。 结果与结论：腺嘌呤核苷酸活化蛋白激酶活化导致哺乳动物雷帕霉素靶蛋白信号转导减弱一定程度上抑制蛋白质合成,腺嘌呤核苷酸活化蛋白激酶通过多个位点磷酸化和活化而调节哺乳动物雷帕霉素靶蛋白信号转导。腺嘌呤核苷酸活化蛋白激酶磷酸化马铃薯球蛋白会抑制Akt,ERK1/ERK2和p90rsk等其他蛋白激酶的作用。明确腺嘌呤核苷酸活化蛋白激酶对哺乳动物雷帕霉素靶蛋白的调节过程所起的作用,对揭示腺嘌呤核苷酸活化蛋白激酶-哺乳动物雷帕霉素靶蛋白途径调控能量代谢和蛋白合成方面有重要意义。     

哺乳动物雷帕霉素靶蛋白在中枢神经系统再生中的作用

成年哺乳动物中枢神经系统(central nervous system, CNS)损伤后再生困难的主要原因是抑制性微环境的存在和其内在的生长能力低下[1].目前关于损伤微环境的大量研究显示,单纯阻断环境抑制信号而不激活神经元内在生长状态(intrinsic growth state),其再生是有限的[2].     

哺乳动物雷帕霉素靶蛋白信号通路相关基因对大鼠再生肝8种细胞生长过程的调节作用

个基因含于大鼠Genome 230 2.0芯片,82个基因与大鼠肝再生相关。其中,在启动阶段,mTOR信号通路主要参与激活、促进肝细胞、陷窝细胞、库普弗细胞、树突状细胞、肝星形细胞和窦内皮细胞的生长过程;在进展阶段,mTOR信号通路明显地促进肝细胞、胆管上皮细胞、卵圆细胞、肝星形细胞、库普弗细胞、陷窝细胞和树突状细胞的生长过程;在终止阶段,mTOR信号通路的大多数途径对肝细胞、库普弗细胞和树突状细胞的生长过程的促进作用减弱,而途径25却对肝细胞、窦内皮细胞、肝星形细胞和陷窝细胞的生长过程有明显的抑制作用。 结论 mTOR信号通路的25条途径和82个基因参与大鼠再生肝8种细胞的生长调控。     

哺乳动物雷帕霉素靶蛋白信号通路在帕金森病中的作用

哺乳动物雷帕霉素靶蛋白（mTOR）是一种保守的丝氨酸/ 苏氨酸蛋白激酶,调控细胞生长、增殖、运 动、存活和自噬等生物学活动,作为细胞代谢和生存的关键调节剂,现已成为帕金森病（PD）的新型治疗靶点。 越来越多的研究表明,在PD模型中恢复受干扰的mTOR信号转导可以预防神经元的死亡。然而,在PD中通过 mTOR介导产生作用的分子机制尚未完全清楚。现将mTOR信号通路与PD关系的最新进展进行综述,并进一步 讨论mTOR信号通路在PD中的潜在作用。     

雷帕霉素及哺乳动物雷帕霉素靶蛋白(mTOR)在免疫调节中的作用研究进展

哺乳动物雷帕霉素靶蛋白(m TOR)是丝氨酸苏氨酸蛋白酶,由雷帕霉素靶蛋白复合物1(m TORC1)和m TORC2组成,具有调节细胞生长、代谢、增殖、存活功能。m TOR及其相关信号通道在多种疾病的病理生理过程中具有重要的调节作用,如自身免疫性疾病系统性红斑狼疮(SLE)、移植排斥反应及肿瘤等。雷帕霉素是m TOR敏感性抑制剂,具有免疫抑制作用,现已用于m TOR相关的多种疾病治疗,我们主要总结了雷帕霉素及m TOR参与疾病免疫调节的作用及机制。     

哺乳动物雷帕霉素靶蛋白在脑生理和病理中的作用

哺乳动物雷帕霉素靶蛋白（mTOR）常被用于研究免疫抑制剂药物雷帕霉素的功能和作用机制。作为丝氨酸/苏氨酸激酶,mTOR有两种功能明显不同的复合体--mTORC1和mTORC2,控制诸如蛋白质合成,能量代谢,细胞大小,脂质代谢,自噬,线粒体功能和溶酶体形成等细胞的基本功能。此外,mTOR控制的信号通路还参与调节神经系统的许多生理功能,包括神经系统的发育,突触可塑性,记忆储存和认知功能。因此, mTOR信号通路失调可能与许多神经和精神疾病的发生有关。前期研究表明,抑制mTORC1对癫痫、认知障碍和脑部肿瘤等疾病的治疗有利,而直接或间接刺激mTORC1一方面可促进脑细胞轴突再生和骨髓鞘形成,另一方面该通路可成为治疗抑郁症的靶点之一。     

哺乳动物雷帕霉素靶蛋白及其对神经退行性疾病影响的研究现状

正神经退行性疾病(neurodegenerative diseases)或许是生命过程中的自然规律,是神经细胞生理性衰老或是病理性衰老的一种形式。这种复杂生物学进程与生命过程的时间推移呈渐进性老化或衰退,体内分子、细胞和器官的退变、自噬或凋亡是其病变进程的本质[1,2]。对神经退行性疾病机制的研究是一个古老而崭新学科,其病理生理、发病机制至今仍在     

The pros and the cons of mTOR inhibitors in kidney transplantation

Sirolimus and its derivate everolimus are two immunosuppressive drugs with similar chemical structure that inhibit the proliferation of T cells by interfering with a serine-threonine kinase, called mTOR. Apart from their immunosuppressive effects, these agents may also inhibit endothelial intimal proliferation, the replication of cytomegalovirus, and the development of certain cancers. The main dose-dependent adverse events of mTOR inhibitors are hyperlipidemia, thrombocytopenia, mucositis, edema, and proteinuria. The use of mTOR inhibitors in renal transplantation may allow to reduce the doses of calcineurin inhibitors. Withdrawal of calcineurin inhibitors is also possible and may improve renal function, but some patients do not tolerate this regimen because of side effects. Further studies are needed to assess the role of mTOR inhibitors in the long-term.     

mTOR在乳腺癌中的表达及其抑制剂对乳腺癌细胞增殖和凋亡的作用

目的：探讨mTOR在乳腺癌中的表达及其抑制剂CCI-779对乳腺癌细胞MDA-MB-231增殖及凋亡的影响。方法采用免疫组化SP法检测mTOR蛋白在乳腺癌组织和乳腺癌细胞MDA-MB-231中的表达;MTT法检测mTOR抑制剂CCI-779对MDA-MB-231细胞增殖的影响;应用AnnexinV-FITC/PI法检测CCI-779对MDA-MB-231细胞凋亡的影响。结果 mTOR蛋白在71例乳腺癌组织中的阳性率为54.9%,明显高于32例癌旁组织(阳性率为21.9%);MDA-MB-231细胞中亦存在mTOR蛋白的表达;mTOR抑制剂CCI-779对MDA-MB-231细胞的增殖具有显著抑制作用,呈浓度和时间依赖性;但CCI-779并不能诱导MDA-MB-231细胞发生凋亡。结论 mTOR与乳腺癌关系密切,其抑制剂CCI-779具有较强的抗MDA-MB-231细胞活性,有望成为乳腺癌治疗的前景药物。     

Protein tyrosine kinase inhibitors in cancer therapy

The tyrosine kinase inhibitors (TKI) are small molecules of low molecular weight that inhibit tyrosine kinases, enzymes responsible for the activation of signal transduction cascades. Currently, a number of TKI received approval in various cancers, while others are in clinical development process: TKI are specifically clinically active when they target a tyrosine kinase (TK) with constitutional activity subsequent to a mutation, being then a master-gene driving transformation and tumour progression. Already, this drug-family provides a major therapeutic weapon against cancer.     

PI3K/Akt/mTOR信号通路及其相关基因突变与子宫内膜癌靶向性药物治疗的研究进展

子宫内膜癌(EC)是最常见的女性生殖道恶性肿瘤之一,其发生发展的分子生物学机制十分复杂。近年来研究发现,磷脂酰肌醇-3激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白(PI3K/Akt/mTOR)信号通路调节异常与子宫内膜癌密切相关。PI3K/Akt/mTOR信号通路中的多种受体及激酶的突变和异常激活,可能成为子宫内膜癌治疗的靶点。     

Synergistic anti-proliferative effects of mTOR and MEK inhibitors in high-grade chondrosarcoma cell line OUMS-27

Chondrosarcoma is a malignant bone tumor that produces cartilaginous neoplastic tissue. Owing to the absence of an effective adjuvant therapy, high-grade chondrosarcoma has a poor prognosis. Therefore, it is important to develop an effective adjuvant therapy to prevent the recurrence and metastasis. Mammalian target of rapamycin (mTOR), a central regulator of cell growth, metabolism, proliferation, and survival, is considered an important target for anticancer drug development. The mitogen activated protein kinase (MAPK) pathway is another highly implicated cellular pathway in cancer and is thought to have compensatory effects in response to the inhibition of the phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR signaling pathway. We investigated the mechanism of anti-proliferative effect of the mTOR inhibitor rapamycin and MAPK/ERK (MEK) inhibitor PD 0325901, and the combined effect of rapamycin and PD 0325901 on human chondrosarcoma cell line (OUMS-27). Combination therapy with rapamycin and PD 0325901 showed a stronger anti-proliferative effect on OUMS-27 cells than rapamycin monotherapy. We confirmed that the dual inhibition of the PI3K/Akt/mTOR and RAF/MEK/ERK signaling pathways had synergistic anti-proliferative effects in OUMS-27. Our results suggest that combination therapy of mTOR and MEK inhibitor could be an effective therapeutic approach against chondrosarcoma.     

Comparing mTOR inhibitor Rapamycin with Torin-2 within the RIST molecular-targeted regimen in neuroblastoma cells

The prognosis for patients with relapsed or refractory high-risk neuroblastoma remains dismal and novel therapeutic options are urgently needed. The RIST treatment protocol has a multimodal metronomic therapy design combining molecular-targeted drugs (Rapamycin and Dasatinib) with chemotherapy backbone (Irinotecan and Temozolomide), which is currently verified in a phase II clinical trial ({"type":"clinical-trial","attrs":{"text":"NCT01467986","term_id":"NCT01467986"}}NCT01467986). With the availability of novel and more potent ATP competitive mTOR inhibitors, we expect to improve the RIST combination therapy. By comparing the IC₅₀ values of Torin-1, Torin-2, AZD3147 and PP242 we established that only Torin-2 inhibited cell viability of all three MycN-amplified neuroblastoma cell lines tested at nanomolar concentration. Single treatment of both mTOR inhibitors induced a significant G₁ cell cycle arrest and combination treatment with Dasatinib reduced the expression of cell cycle regulator cyclin D1 or increased the expression of cell cycle inhibitor p21. The combinatorial index depicted for both mTOR inhibitors a synergistic effect with Dasatinib. Interestingly, compared to Rapamycin, the combination treatment with Torin-2 resulted in a broader mTOR pathway inhibition as indicated by reduced phosphorylation of AKT (Thr308, Ser473), 4E-BP (Ser65), and S6K (Thr389). Furthermore, substituting Rapamycin in the modified multimodal RIST protocol with Torin-2 reduced cell viability and induced apoptosis despite a significant lower Torin-2 drug concentration applied. The efficacy of nanomolar concentrations may significantly reduce unwanted immunosuppression associated with Rapamycin. However, at this point we cannot rule out that Torin-2 has increased toxicity due to its potency in more complex systems. Nonetheless, our results suggest that including Torin-2 as a substitute for Rapamycin in the RIST protocol may represent a valid option to be evaluated in prospective clinical trials for relapsed or treatment-refractory high-risk neuroblastoma.     

Use of mTOR inhibitors in human organ transplantation

The mammalian target of rapamycin (mTOR) inhibitor drugs rapamycin (sirolimus) and everolimus have undergone extensive clinical trials for a variety of organ grafts and have been licensed for use in human transplantation. Uniquely, they block the function of a master chemical switch, the protein kinase mTOR, which integrates the multiple biochemical pathways that are necessary for growth factors to induce cell proliferation. Many of these pathways are abnormal in tumorigenesis, and the role of mTOR and its inhibitors in cancer treatment is undergoing intense investigation. There are pharmacokinetic differences between the rapamycins, however, in all major respects, their actions are the same. They show synergy with the calcineurin inhibitors in antirejection effects but also augment the nephrotoxicity of both cyclosporine and tacrolimus. They allow marked reduction in calcineurin inhibitor drug doses, which also reduces the nephrotoxicity of the combinations. In clinical trials in kidney, heart, lung, small bowel, pancreas, islet and liver transplantation in combination with cyclosporine and tacrolimus, rejection rates are equivalent or superior to those achieved with mycophenolate mofetil combinations. Despite this, its clinical usage remains limited. The side-effect profile, especially elevations in serum lipids and nephrotoxicity when administered in combination with calcineurin inhibitors, are the major factors. However, these drugs are finding an increasing place in other areas of medicine, including incorporation into endovascular coronary artery and peripheral arterial stents and in cancer therapy. Their ability to reduce fibrosis and neovascularization suggests other areas of potential use.     

Additive cytotoxic effects of radiation and mTOR inhibitors in a cervical cancer cell line

The PI3 K/AKT/mTOR signaling pathway is frequently activated in HPV-positive cervical squamous cell cancer (CC). This study investigated the biological effects of mTOR inhibitors associated with radiotherapy in a CC cell line (HeLa). A human keratinocyte cell line (HaCaT) was used as control. Temsirolimus, everolimus, resveratrol, curcumin and epigallocatechin gallate (EGCG) were the mTOR inhibitors assessed. The 50% cell cytotoxicity rate (CC₅₀) for each treatment was determined by MTT cell viability assay. Cells were pre-treated with mTOR inhibitors at CC₅₀ followed by radiotherapy (RT) at 2 Gy. Cell death profile after treatment with temsirolimus, resveratrol and curcumin was assessed with flow cytometry. Everolimus, temsirolimus, EGCG, resveratrol and curcumin were cytotoxic to HeLa. Radiation induced a statistically significant (p < 0.01) supra-additive cytotoxic effect in the cervical cancer cell line when combined with mTOR inhibitors. After a 24-h treatment, EGCG and resveratrol were more cytotoxic to HeLa cells than to HaCaT cells. After 48 h of treatment, resveratrol, curcumin and everolimus were more cytotoxic to HeLa cells when compared to HaCaT cells. After 24 h, temsirolimus induced late apoptosis or necrosis in HeLa cells. Based on these data, new studies with mTOR inhibitors as treatment options for cervical cancer are recommended, mainly combined to radiotherapy.     

用于肿瘤联合治疗的基因和化疗药物纳米共载体系的研究进展

化学药物治疗（化疗）或基因治疗单独使用治疗肿瘤均具有较多缺陷,而将两者联合应用能协同治疗肿瘤,克服单一疗法的不足.纳米载体既能包载化疗药物又能递送基因,其用于肿瘤的联合治疗,可减少化疗药物的剂量,增加药物在靶器官的分布量,减轻毒副作用,从而提高抗肿瘤效果;同时保护携带基因的稳定性和完整性,一定程度上提高基因的转染效率,以达到减轻毒副作用及提高疗效的协同目的.基因和化疗药物纳米共载体系用于肿瘤的联合治疗是近年来肿瘤治疗的研究热点.就基因和化疗药物纳米共载体系的类型及负载基因类型,特别是纳米共载体系用于肿瘤联合治疗的研究进行总结和展望.     

AM激活mTOR信号通路对人卵巢癌细胞增殖的影响

目的探讨肾上腺髓质素(Adrenomedullin,AM)通过激活mTOR(哺乳动物雷帕霉素靶蛋白)信号途径对人卵巢癌细胞HO8910增殖的影响。方法应用AM及mTOR拮抗剂(雷帕霉素)诱导卵巢癌细胞,CCK8法检测AM及雷帕霉素对卵巢癌细胞增殖的影响,进一步采用Western印迹法,测定AM对mTOR磷酸化的激活作用结果 AM可促进卵巢癌细胞的增殖,并呈剂量依赖关系及受体依赖关系,而这种促增殖作用可被mTOR信号通路的拮抗剂雷帕霉素所抑制;随着AM浓度的增加,卵巢癌细胞mTOR磷酸化水平随之升高。结论AM介导的mTOR信号通路促进卵巢癌细胞增殖,为卵巢癌的分子靶向治疗提供新的思路。