HSP90抑制剂在肿瘤临床中的研究进展

0 引言 分子靶向抗肿瘤治疗是目前肿瘤治疗研究领域的热点,并取得了令人瞩目的疗效.最著名的例子是BCR-ABL特异性抑制剂格列卫在慢性髓系白血病中的应用[1].作为靶点的分子通常是与致癌信号通路相关的蛋白激酶,但是研究发现单个蛋白激酶分子的靶向治疗通常只对少数肿瘤细胞有效,而且敏感的肿瘤细胞通常会发展为获得性抵抗.分子靶向治疗的最新进展提示有效的控制肿瘤需要同时抑制多个致癌信号通道[2].HSP90是一类普遍存在于各种细胞的分子伴侣蛋白,在肿瘤细胞中,HSP90通过调节多种癌蛋白的功能,从而参与调节肿瘤细胞的增殖、生存、侵袭、转移和血管生成等多种重要过程.由于HSP90对多种癌蛋白具有调控作用,通过对HSP90的抑制可以实现同时对多种肿瘤信号通路的调控,从而有效控制肿瘤.HSP90抑制剂的开发研究已经成为分子靶向抗肿瘤治疗的一个热点,近年来国外大量研究开发出了多种HSP90抑制剂,本文对HSP90抑制剂在多种肿瘤的临床研究进展讲行综述.     

Hsp90α和传统肿瘤标志物诊断效能的对比分析

目的:对比分析Hsp90α和传统肿瘤标志物在不同类型肿瘤患者血清中的表达情况。方法:对706例明确诊断的不同类型肿瘤患者和68例健康患者进行肿瘤标志物血清含量测量,应用配对资料t检验分析Hsp90α和传统肿瘤标志物在不同类型肿瘤患者中的血清表达。结果:在384例肺癌患者血清检测中,Hsp90α阳性率为46.6%,CEA、CY211、NSE阳性率分别为24.7%、20.8%、29.9%,4种肿瘤标志物联合诊断阳性率为70.8%;在乳腺癌、肝癌、肠癌、胃癌、食管癌、淋巴瘤中,Hsp90α阳性率分别为41.9%、53.3%、30.0%、44.7%、23.7%、46.8%,相关肿瘤标志物联合诊断阳性率分别为58.1%、71.4%、56.0%、53.2%、30.3%、52.6%;在宫颈癌、卵巢癌、子宫内膜癌、胆囊癌、胰腺癌、头颈肿瘤（鼻咽癌、腮腺肿瘤、舌癌）Hsp90α阳性率分别为50.0%、50.0%,60.0%、40.0%、42.9%、36.4%。结论:Hsp90α在多种肿瘤中都有较高的阳性率,和其它肿瘤标志物联合诊断能进一步提高诊断阳性率,是一个值得关注的新型临床肿瘤标志物。     

免疫检查点抑制剂在血液肿瘤中的研究进展

以抗程序性死亡受体1（PD-1）抗体为代表的免疫检查点抑制剂（ICI）在实体肿瘤治疗中取得重大突破。近年来ICI开始在血液肿瘤中应用,多项临床试验显示其具有较好的疗效并可显著改善患者预后。文章结合2020年第62届美国血液学会（ASH）年会报道,介绍ICI在血液肿瘤治疗中的相关临床研究进展。     

PARP抑制剂联合纳米材料在恶性肿瘤治疗中的研究进展

恶性肿瘤已成为全球第二大死因.传统治疗方案有手术、化疗、放疗及生物治疗等.由于化疗药物的细胞毒性作用,不仅抑制肿瘤细胞的快速增殖,也使其他重要器官受到毒性损害,从而导致多种不良反应.为了加强肿瘤靶向性的同时,又能减轻药物不良反应,精准靶向治疗的治疗模式逐渐开展,纳米材料则作为药物载体,以其靶向性强、不良反应小等优点进入...     

格尔德霉素在鼻咽癌临床治疗中的应用

热体克蛋白90（heat shock protein 90,Hsp90）是生物进化过程中具有一定保守性质的蛋白质,研究发现多种肿瘤的发生发展与其异常表达有关。Hsp90抑制剂与Hsp90结合,抑制了Hsp90的活性,诱导Hsp90作用蛋白降解,从而阻断了细胞的增殖、生长,是一类具有开发前景的抗肿瘤药物。本文就Hsp90抑制剂格尔德霉素（geldnamycin,GA）在鼻咽癌治疗中的应用进行了简要综述。     

ILK、Hsp90相互作用及在胃癌中表达的研究

目的:探讨ILK与Hsp90在胃癌组织中的相互作用,了解它们及相关因子E-cadherin与胃癌临床病理的关系,以及胃癌患者血清中手术前后ILK与Hsp90含量的变化.方法:用免疫共沉淀,蛋白杂交的方法研究ILK与Hsp90的直接相互作用,用免疫组织化学方法测定ILK,Hsp90,E-cadherin和MMP2在胃癌及癌旁组织表达,比较它们与胃癌临床病理的关系,使用Elisa方法,测定ILK与Hsp90在胃癌患者血清中手术前后含量的变化.结果:用ILK抗体免疫沉淀下来的蛋白中检测有Hsp90蛋白存在.ILK在40例胃癌组织中有28例表达阳性,阳性率为70%,而Hsp90则在37例有高表达,阳性率为.92.5%.其中28例ILK阳性者中有27位Hsp90表达阳性.高分化胃癌分别有50%和75%表达,而低分化者为75%和100%.E-cadherin在正常胃粘膜上皮细胞均为阳性表达,而只有40%的胃癌组织呈阳性.其中高分化者有75%阳性表达,而低分化者仅为32.1%,没有转移的为90%,有转移的仅是23.3%.MMP2在癌组织中的表达阳性率为75%,高于癌旁正常组织,高分化者有50%阳性表达,而低分化者为78.6%,没有转移的为50%,有转移的是83.3%.用Elisa方法测定血清中ILK,Hsp90抗体的含量.结果表明,手术前ILK、Hsp90的含量分别为171.0ng/ml和199.0ng/ml,而手术后分别下降为142.6ng/ml和161.6ng/ml.结论:实验结果证明胃癌组织Hsp90与ILK的相互作用是直接的结合.ILK,Hsp90,E-cadherin和MMP2的表达与肿瘤分化程度显著相关,与淋巴结转移、浸润深度、TNM分期也有一定的关系.这些因子的表达对胃癌的分化程度有重要作用,血清的检测ILK和Hsp90可能对术后状况的监控有一定指导意义.     

蛋白激酶小分子抑制剂在肿瘤治疗中的研究进展

蛋白激酶的异常功能与肿瘤密切相关,通过研发相应的蛋白激酶抑制剂调控对应的信号转导通路是现今抗肿瘤药物开发的重点与热点。自从第一种蛋白激酶抑制剂在2001年被美国食品药品监督管理局(FDA)批准上市以来,已有50余种激酶抑制剂获得批准用于治疗乳腺癌和肺癌等恶性肿瘤,在肿瘤患者的治疗中起到重要的作用。小分子蛋白激酶抑制剂同样存在许多亟待解决的问题,为此,研究者不断地开发新的激酶靶向药物来克服发现的问题,许多新的小分子激酶抑制剂已处于临床试验阶段。本综述就抗肿瘤小分子蛋白激酶抑制剂的分类、作用底物以及作用机理进行分析和总结,并系统阐述抗肿瘤小分子激酶抑制剂的研发现状、研究进展和发展趋势。     

Hsp90潜在抑制剂姜黄素诱导人宫颈癌Hela细胞凋亡的机制

目的:研究姜黄素对人宫颈癌细胞Hela的抑制作用及对Hsp90信号通路的影响.方法:MTT法检测姜黄素对Hela细胞的增殖抑制作用.划痕实验检测姜黄素对细胞浸润侵袭的影响.流式细胞术检测姜黄素促进细胞凋亡的效果.Western blotting检测姜黄素对Hela细胞内Hsp90、Hsp70、AKT及Her-2蛋白表达的影响.结果:作用48h后,姜黄素对Hela细胞的增殖抑制呈现出显著的剂量依赖性(P＜0.01),当药物浓度为100 μmol/L时抑制率达到(87.5 ±3.5)％,IC50值为(41.8 ±2.3)μmol/L.划痕实验表明,姜黄素能抑制细胞的浸润和迁移.流式细胞结果显示,姜黄素能有效的促进Hela细胞凋亡,40 μmol/L组细胞的凋亡率即从原来的(10.3±0.6)％提高至(19.1±1.5)％(P＜0.05),当药物浓度达到100 μmol/L时凋亡率达到(55.8±2.6)％.Westem blotting结果显示,姜黄素能引起Hsp70蛋白表达上调,并促进Hsp90下游客户蛋白AKT及Her-2降解.结论:姜黄素表现出较强的抗Hela细胞活性,其机制可能是通过抑制Hsp90活性,影响相关信号通路引起的.     

CDK4/6抑制剂治疗消化道肿瘤的研究进展

摘 要：CDK4/6抑制剂（CDK4/6 inhibitors,CDK4/6i）通过调控Rb/E2F通路,诱导细胞周期停滞,抑制细胞增殖,发挥抗肿瘤作用,被FDA批准用于乳腺癌的治疗,并在多个瘤种中被广泛研究。在消化道肿瘤相关研究中,CDK4/6i表现出较好的抗肿瘤活性,并可与化疗、靶向治疗、免疫治疗和放疗等产生良好的协同效果。全文现就CDK4/6i近年在消化道肿瘤的研究进展作一综述。     

肿瘤治疗分子靶点Hsp90研究进展

热休克蛋白90(Hsp90)是维持细胞内蛋白构象稳定与功能正常所必需的分子伴侣.近年来随着Hsp90特异性抑制剂不断发现,其在肿瘤发生与治疗中的作用正被逐渐揭示,使之成为目前最有希望的抗肿瘤药物作用靶点之一.现对该领域研究进展作一简要综述.     

Novel Hsp90 inhibitor NVP-AUY922 radiosensitizes prostate cancer cells

Outcomes for poor-risk localized prostate cancers treated with radiation are still insufficient. Targeting the “non-oncogene” addiction or stress response machinery is an appealing strategy for cancer therapeutics. Heat-shock-protein-90 (Hsp90), an integral member of this machinery, is a molecular chaperone required for energy-driven stabilization and selective degradation of misfolded “client” proteins, that is commonly overexpressed in tumor cells. Hsp90 client proteins include critical components of pathways implicated in prostate cancer cell survival and radioresistance, such as androgen receptor signaling and the PI3K-Akt-mTOR pathway. We examined the effects of a novel non-geldanamycin Hsp90 inhibitor, AUY922, combined with radiation (RT) on two prostate cancer cell lines, Myc-CaP and PC3, using in vitro assays for clonogenic survival, apoptosis, cell cycle distribution, γ-H2AX foci kinetics and client protein expression in pathways important for prostate cancer survival and radioresistance. We then evaluated tumor growth delay and effects of the combined treatment (RT-AUY922) on the PI3K-Akt-mTOR and AR pathways in a hind-flank tumor graft model. We observed that AUY922 caused supra-additive radiosensitization in both cell lines at low nanomolar doses with enhancement ratios between 1.4–1.7 (p < 0.01). RT-AUY922 increased apoptotic cell death compared with either therapy alone, induced G₂-M arrest and produced marked changes in client protein expression. These results were confirmed in vivo, where RT-AUY922 combination therapy produced supra-additive tumor growth delay compared with either therapy by itself in Myc-CaP and PC3 tumor grafts (both p < 0.0001). Our data suggest that combined RT-AUY922 therapy exhibits promising activity against prostate cancer cells, which should be investigated in clinical studies.     

Antitumor activity of the combination of an HSP90 inhibitor and a PI3K/mTOR dual inhibitor against cholangiocarcinoma

The PI3K/Akt/mTOR pathway is overactivated and heat shock protein (HSP) 90 is overexpressed in common cancers. We hypothesized that targeting both pathways can kill intrahepatic cholangiocarcinoma (CCA) cells. HSP90 and PTEN protein expression was evaluated by immunohistochemical staining of samples from 78 patients with intrahepatic CCA. CCA cell lines and a thioacetamide (TAA)-induced CCA animal model were treated with NVP-AUY922 (an HSP90 inhibitor) and NVP-BEZ235 (a PI3K/mTOR inhibitor) alone or in combination.Both HSP90 overexpression and loss of PTEN were poor prognostic factors in patients with intrahepatic CCA. The combination of the HSP90 inhibitor NVP-AUY922 and the PI3K/mTOR inhibitor NVP-BEZ235 was synergistic in inducing cell death in CCA cells. A combination of NVP-AUY922 and NVP-BEZ235 caused tumor regression in CCA rat animal model. This combination not only inhibited the PI3K/Akt/mTOR pathway but also induced ROS, which may exacerbate the vicious cycle of ER stress. Our data suggest simultaneous targeting of the PI3K/mTOR and HSP pathways for CCA treatment.     

Hsp90 Inhibitor; NVP-AUY922 in Combination with Doxorubicin Induces Apoptosis and Downregulates VEGF in MCF-7 Breast Cancer Cell Line

Objective: Breast cancer is one of the most prevalent malignancies and leading causes of females’ mortality worldwide. Because of resistance to various treatment options, new treatments based on molecular targeting has introduced as noticeable strategies in cancer treatment. In this regard, heat shock protein 90 (Hsp90) inhibitors are proposed as effective anticancer drugs. The goal of the study was to utilize a combination of the doxorubicin (DOX) and NVP-AUY 922 on the MCF-7 breast cancer model to investigate the possible cytotoxic mechanisms. Methods: MCF-7 breast cancer cell line was prepared and treated with various concentrations of DOX and NVP-AUY922 in single-drug treatments. We investigated the growth-inhibitory pattern by MTT assay after continuous exposure to NVP-AUY922 and DOX in order to determine dose-response. Then the combinatorial effects were evaluated in concentrations of 0.5 × IC50, 0.2 × IC50, 1 × IC50 and, 2 × IC50 of each drugs. Based on MTT results of double combinations, low effective doses were selected for Real-time PCR [caspase3 and vascular endothelial growth factor(VEGF)] and caspase 3 enzyme activity. Results: A dose-dependent inhibitory effects were presented with increasing the doses of both drugs in single treatments. The upregulation of caspase 3 and downregulation of VEGF mRNA were observed in double combinations of NVP-AUY922 and DOX versus single treatments. Also, in these combinations in low doses of examined drugs (0.5 × IC50, 0.2 × IC50), higher caspase 3 activity were presented in comparison to single treatments (p<0.05). Conclusions: Our findings indicate an effective action of NVP-AUY922 in combined with DOX in this cell line. These results can predict the treatment outcome in this model.     

A novel C-terminal HSP90 inhibitor KU135 induces apoptosis and cell cycle arrest in melanoma cells

Heat shock protein 90 (Hsp90) is differentially expressed in tumor cells including melanoma and involved in proper folding, stabilization and regulation of cellular proteins. We investigated a novobiocin-derived Hsp90 C-terminal inhibitor, KU135, for anti-proliferative effects in melanoma cells. The results indicate that KU135 reduced cell viability and cell proliferation in melanoma cells and IC₅₀ values for A735(DRO), M14(NPA), B16F10 and SKMEL28 cells were 0.82, 0.92, 1.33 and 1.30 μM respectively. KU135 induced a more potent anti-proliferative effect in most melanoma cells versus N-terminal Hsp90 inhibitor 17AAG. KU135 induced apoptosis in melanoma cells, as indicated by annexin V/PI staining, reduction in the mitochondrial membrane potential, mitochondrial cytochrome C release and caspase 3 activation. KU135 reduced levels of Hsp90 client proteins Akt, BRAF, RAF-1, cyclin B and cdc25. Additionally, levels of Hsp90 and Hsp70 did not increase, while the levels of phosphorylated HSF1 levels decreased. KU135 induced strong G2/M cell cycle arrest, associated with decreased expression of cdc25c, cyclin B and increased phosphorylation of cdc25c. These finding show that KU135 reduced cell survival, proliferation, and induces apoptosis in melanoma cells. We suggest that KU135 may be a potential candidate for cancer therapy against melanoma.     

Preferential radiosensitization to glioblastoma cancer stem cell-like cells by a Hsp90 inhibitor,N-vinylpyrrolidone-AUY922

The present study examined the radiosensitization induced by a heat shock protein 90 inhibitor, N-vinylpyrrolidone (NVP)-AUY922, in CD133-positive cells in a hypoxic area of T98G spheroids. CD133-positive cells that are induced in the hypoxic microenvironment of spheroids have previously been reported to exhibit cancer stem cell-like properties. The present study used CD133-positive cells from a glioblastoma cell line (T98G) as cancer stem cell-like cells. CD133-positive and negative cells were sorted from T98G spheroids using fluorescence-activated cell sorting and used for colony formation assay. Colony formation assay results indicated that NVP-AUY922 enhanced radiosensitivity more strongly in CD133-positive cells compared with CD133-negative cells. This result showed that NVP-AUY922 was a preferential radiosensitization candidate targeting glioblastoma cancer stem cells. The mechanisms underlying radiosensitization by NVP-AUY922 are discussed in relation to the properties of cancer stem cells. Overall, HIF-1α inhibition by NVP-AUY922 may induce higher sensitization of cancer stem cells to radiation.     

NVP-AUY922: a small molecule HSP90 inhibitor with potent antitumor activity in preclinical breast cancer models

Introduction

Heat shock protein 90 (HSP90) is a key component of a multichaperone complex involved in the post-translational folding of a large number of client proteins, many of which play essential roles in tumorigenesis. HSP90 has emerged in recent years as a promising new target for anticancer therapies.

Methods

The concentrations of the HSP90 inhibitor NVP-AUY922 required to reduce cell numbers by 50% (GI₅₀ values) were established in a panel of breast cancer cell lines and patient-derived human breast tumors. To investigate the properties of the compound in vivo, the pharmacokinetic profile, antitumor effect, and dose regimen were established in a BT-474 breast cancer xenograft model. The effect on HSP90-p23 complexes, client protein degradation, and heat shock response was investigated in cell culture and breast cancer xenografts by immunohistochemistry, Western blot analysis, and immunoprecipitation.

Results

We show that the novel small molecule HSP90 inhibitor NVP-AUY922 potently inhibits the proliferation of human breast cancer cell lines with GI₅₀ values in the range of 3 to 126 nM. NVP-AUY922 induced proliferative inhibition concurrent with HSP70 upregulation and client protein depletion – hallmarks of HSP90 inhibition. Intravenous acute administration of NVP-AUY922 to athymic mice (30 mg/kg) bearing subcutaneous BT-474 breast tumors resulted in drug levels in excess of 1,000 times the cellular GI₅₀ value for about 2 days. Significant growth inhibition and good tolerability were observed when the compound was administered once per week. Therapeutic effects were concordant with changes in pharmacodynamic markers, including HSP90-p23 dissociation, decreases in ERBB2 and P-AKT, and increased HSP70 protein levels.

Conclusion

NVP-AUY922 is a potent small molecule HSP90 inhibitor showing significant activity against breast cancer cells in cellular and in vivo settings. On the basis of its mechanism of action, preclinical activity profile, tolerability, and pharmaceutical properties, the compound recently has entered clinical phase I breast cancer trials.     

HSP90 inhibitor AUY922 can reverse Fulvestrant induced feedback reaction in human breast cancer cells

Hormone therapy has become one of the main strategies for breast cancer, however, many estrogen receptor (ER) positive patients end in tumor collapse due to initial or acquired resistance to hormone treatment, which includes Fulvestrant. Here we report that ErbB receptors and downstream PI3K/AKT and ERK pathway have been reactivated after treatment of Fulvestrant in ER positive MCF‐7 and T47D cells, which are related to Fulvestrant resistance. HSP90 is a universally expressed chaperone protein and plays a vital role in both normal and cancer cells, HSP90 inhibitor AUY922 can reverse this feedback reactivation effect of Fulvestrant by targeting multiple proteins related in ErbB receptors, PI3K/AKT and ERK pathway, which is much better than single targeting inhibitors. We also consolidate these effects in human fresh breast tumors. Combination of AUY922 and Fulvestrant may become a promising therapy strategy in breast cancer treatment.