高分子材料调控肿瘤免疫微环境的研究进展

随着肿瘤免疫疗法在临床应用取得巨大突破,通过抗肿瘤免疫反应提高抗肿瘤疗效的治疗方式受到了广泛的关注.然而,肿瘤组织存在复杂的免疫抑制性微环境,严重限制了部分免疫疗法的效果.长期以来,高分子材料作为重要的药物递送载体受到广泛关注,但是其在调控肿瘤免疫微环境的功能及应用方面尚未引起足够的重视.在本文中,我们一方面介绍了肿瘤组织形成免疫抑制性微环境的成因,如肿瘤组织存在多种免疫抑制性细胞,如调节性T细胞(Tregs)、髓系来源抑制性细胞(MDSCs)和肿瘤相关巨噬细胞(TAMs)等,以及免疫细胞、肿瘤细胞等分泌的大量细胞因子、趋化因子、代谢产物等.另一方面,重点介绍了近年来高分子材料作为载体递送免疫调节分子或发挥自身免疫调节功能,调控或逆转免疫抑制性微环境的策略和典型代表,证明了高分子材料在调控肿瘤免疫微环境,改善肿瘤治疗效果方面的巨大潜力.     

金属配合物在肿瘤化学免疫治疗中的应用前景

肿瘤化学免疫治疗是免疫疗法与化学疗法相结合通过协同作用治疗肿瘤的一种新方法。以铂类药物为代表的金属药物是一类重要的化学抗肿瘤药物,其作用机理是与肿瘤细胞DNA形成交联物并阻止其复制;但是,这类药物存在严重的毒性和耐药性问题。近年来发现有些金属配合物在产生细胞毒性的同时,也通过多种机制参与机体的免疫调节过程,其中以诱导免疫原性细胞死亡（ICD）最为常见。本文简要介绍了肿瘤化学免疫治疗的基本概念以及与免疫抑制有关的肿瘤微环境,概述了金属配合物的免疫活性和调节免疫过程的基本原理,并以铂类药物为例总结了金属配合物调节免疫过程的可能途径,最后列举了若干具有ICD诱导潜力和其他免疫调节功能的非铂类金属配合物,指出了目前化学免疫治疗存在的问题和未来的应用潜力。化学治疗与免疫治疗结合既可以利用机体免疫系统增强金属配合物的抗肿瘤效果,又可以减少药物剂量,降低毒副作用,是设计金属抗肿瘤药物的新方向之一。     

抗肿瘤缺氧诱导因子-1的小分子抑制剂

肿瘤的缺氧微环境与其增殖、分化、血管生成、能量代谢、耐药性的发生以及患者预后状况密切相关。缺氧诱导因子1(Hypoxia-inducible factor 1, HIF-1)是细胞适应缺氧环境的重要转录因子和调控蛋白,通过调控下游靶基因如EPO、VEGF、GLUT等的表达,促进血管新生及有氧糖酵解以适应缺氧的环境,进而影响肿瘤细胞代谢、血管生成和肿瘤转移等。因此,开发以HIF-1为靶标的小分子抑制剂药物有望成为一种有效的肿瘤治疗方法。本文就HIF-1小分子抑制剂在肿瘤学研究中的进展进行综述,旨在为靶向HIF-1抗肿瘤药物的研发提供新思路。     

微流控芯片-质谱联用技术在细胞代谢与药物代谢中的研究进展

细胞代谢与药物代谢是新药筛选和研发的关键环节,在推动人类大健康发展进程中具有重要意义。通常情况下,细胞代谢和药物筛选以传统细胞培养测定研究为主,多为静态培养条件,无法很好地模拟体内细胞动态微环境。微流控芯片-质谱联用是近年发展起来的一种新型高通量分析技术。微流控芯片模块可高度模拟细胞体内动态微环境,与质谱联用可实时在线检测样品物质,具有高效、快速、简便、样品和试剂消耗低等特点,广泛应用于细胞代谢和药物代谢分析,有利于加速药物筛选研发进程。该文重点综述了微流控芯片-质谱联用技术及其在细胞代谢和药物代谢方面的应用概况,并对目前存在的局限性进行了讨论和展望,以期为微流控芯片-质谱联用技术在新药研发与细胞分析领域的发展提供参考。     

微量元素与激素

微量元素可以在激素的分泌、活性以及与组织的结合等各个环节上影响激素。反之，激素也可以调控机体微量元素的代谢过程。     

几种化学计量学方法在放线菌及其次生代谢产物抗肿瘤活性筛选中的应用

当今肿瘤的诊断与治疗对人类健康非常重要. 在放线菌次生代谢产物内寻找抗肿瘤抗生素的过程中, 如何从种类多、数量大的土壤放线菌株中确定目标菌株, 筛选是关键. 将化学计量学方法用于大批量的放线菌及其次生代谢产物的筛选数据分析, 首先通过主成分分析获得具有抗肿瘤活性菌株对6种肿瘤细胞抑制作用的一些关系与特异性, 其次在进行菌株次生代谢产物的分子模型筛选数据分析时, 利用比较分析发现有较好肿瘤抑制作用者, 基本与细胞筛选结果吻合. 二者结合建立了一种简便适当的分析模式, 能较快地从大批量放线菌株的筛选中找到具有抗肿瘤活性的有研究价值的目标放线菌株.     

色谱指纹谱用于中药大黄抗肿瘤活性成分的筛选

采用液相色谱-质谱联用方法分析了中药大黄经过SD大鼠肝匀浆体外代谢前后的指纹谱中色谱峰面积、保留值的差异。指出5种游离型蒽醌化合物在SD大鼠肝匀浆体外代谢体系中只有大黄酚发生代谢反应转化为芦荟大黄素。考察了体外代谢条件下,肝匀浆浓度与代谢时间对大黄酚转化及其代谢产物的影响。SD大鼠体外抗肿瘤试验表明,大黄代谢物对于人宫颈癌(HeLa)细胞的抑制活性略高于其提取物。通过比较芦荟大黄素、大黄酸、大黄素、大黄酚、大黄素甲醚的活性,并结合大黄酚的体外代谢反应的考察,解释了大黄代谢物对肿瘤细胞活性的抑制率的提高是由大黄酚的代谢产物芦荟大黄素浓度的增加引起的。     

模拟体内微环境筛选与肿瘤细胞作用的中药活性成分

利用三维(3D)细胞反应器模拟体内微环境,建立了一种与肿瘤细胞作用的活性分子的筛选和分析方法.利用药物与三维细胞反应器中活肿瘤细胞和固化肿瘤细胞分别作用后的HPLC生物指纹谱峰面积之间有无显著性差异,建立了与细胞结合的活性成分的筛选识别模型.已知抗肿瘤药物紫杉醇和白藜声醇的谱峰均具有显著性差异,而非抗肿瘤药物酮洛芬和青霉素G的谱峰均没有显著性差异,证明利用该模型筛选识别与细胞结合的活性成分是可行的.此外,应用该模型从中草药桃儿七提取物中筛选出了7种可作用于Lovo细胞的活性成分.此研究提供了一种模拟体内微环境下与肿瘤细胞作用的活性成分的筛选和分析方法,在药物发现环节,特别是中草药活性成分研究中具有潜在的应用价值.     

抗肿瘤纳米材料

<正>蓬勃发展的纳米材料为肿瘤的安全高效治疗提供了有潜力的平台,其主要应用于肿瘤精确诊断、药物靶向递送、微环境调控和自身免疫系统激活等方面^[1-2]。本文简述了该领域发表于《应用化学》上的最新研究成果,并展望了抗肿瘤纳米材料在临床应用中的机遇与挑战。     

南海红树林内生真菌ZSUH 36次级代谢物的分离鉴定

红树林;内生真菌;次级代谢产物;抗肿瘤活性     

Sodium Bicarbonate Nanoparticles for Amplified Cancer Immunotherapy by Inducing Pyroptosis and Regulating Lactic Acid Metabolism

Although immunotherapy has a broad clinical application prospect, it is still hindered by low immune responses and immunosuppressive tumor microenvironment. Herein, a simple and drug-free inorganic nanomaterial, alkalescent sodium bicarbonate nanoparticles (NaHCO₃ NPs), is prepared via a fast microemulsion method for amplified cancer immunotherapy. The obtained alkalescent NaHCO₃ regulates lactic acid metabolism through acid-base neutralization so as to reverse the mildly acidic immunosuppressive tumor environment. Additionally, it can further release high amounts of Na⁺ ions inside tumor cells and induce a surge in intracellular osmolarity, and thus activate the pyroptosis pathway and immunogenic cell death (ICD), release damage-associated molecular patterns (DAMPs) and inflammatory factors, and improve immune responses. Collectively, NaHCO₃ NPs observably inhibit primary/distal tumor growth and tumor metastasis through acid neutralization remitted immunosuppression and pyroptosis induced immune activation, showing an enhanced antitumor immunity efficiency. This work provides a new paradigm for lactic acid metabolism and pyroptosis mediated tumor treatment, which has a potential for application in clinical tumor immunotherapy.     

Local T regulatory cells depletion by an integrated nanodrug system for efficient chem-immunotherapy of tumor

T regulatory(Treg) cell is a major immunosuppressive factor that restrains the antitumor effect of immunotherapy, because it gets more after the immune activation and is hardly to be eliminated. Here, an acid-sensitive integrated nanodrug system is designed to activate antitumor immune response as well as locally deplete Treg cells with low side effect. The nanosystem is synthetized by coordinating doxorubicin(DOX) and pentoxifylline(PTX) with Zn ions, then stabilized via liposome encapsulation(denoted as DTX@Lipo). DTX@Lipo can activate antitumor immune effect by chemotherapy of DOX. Besides, the release of PTX inhibits c-Rel expression, leading to the reduction of Treg cells in tumor site. Owing to the good tumor accumulation and local drug release ability, DTX@Lipo exhibits better biosafety and convenience than traditional antibody blockade method for Treg cells depletion. According to the results of in vivo experiments, the nanodrug system can significantly increase the ratio between effector T(Teff) cells and Treg cells locally, resulting in an immunoactivated tumor microenvironment. Importantly, it exhibits significant antitumor effect when combined with PD-1 blockade therapy, providing great potential for tumor therapy.     

Enhanced antitumor chemo-immunotherapy by local co-delivery of chemotherapeutics,immune checkpoint blocking antibody and IDO inhibitor using an injectable polypeptide hydrogel

The efficiency of antitumor immunotherapy is usually limited by the immunosuppressive tumor microenvironment (TME). In this study, we developed a chemo-immunotherapy strategy that is able to improve the immunosuppressive TME for enhancing the antitumor efficacy. The chemo-immunotherapy was achieved by the topical co-delivery of a chemotherapeutic drug, Doxorubicin (DOX), an immune checkpoint blocking antibody targeting programmed cell death protein 1 (aPD-1), and an indoleamine-2,3-dioxygenase (IDO) inhibitor, 1-methyl-d -tryptophan (d -1MT) by using a thermosensitive polypeptide hydrogel. It was revealed that the sustained DOX release from the hydrogel caused the immunogenic cell death (ICD) of B16F10 cells in vitro, and the tumor cell lysates subsequently promoted the activation of dendritic cells (DCs). After intratumoral injection into B16F10 melanoma-bearing mice, the DOX/aPD-1/D-1MT co-loaded hydrogel exhibited enhanced tumor inhibition efficacy and prolonged animal survival time, compared to the DOX/aPD-1/D-1MT mixed solution, DOX-loaded hydrogel or DOX/aPD-1 co-loaded hydrogel. The improvement of immunosuppressive TME and enhancement of antitumor immune response after the local chemo-immunotherapy were demonstrated by the augmented activation of DCs and increased infiltration of CD8⁺ and CD4⁺ T cells, as well as enhanced secretion of pro-inflammatory cytokines. Therefore, the hydrogel-based local chemo-immunotherapy system holds great potential for effective antitumor treatment.     

A Polymeric Extracellular Matrix Nanoremodeler for Activatable Cancer Photo-Immunotherapy

Cancer immunotherapy has shown tremendous potential to train the intrinsic immune system against malignancy in the clinic. However, the extracellular matrix (ECM) in tumor microenvironment is a formidable barrier that not only restricts the penetration of therapeutic drugs but also prevents the infiltration of antitumor immune cells. We herein report a semiconducting polymer-based ECM nanoremodeler (SPNcb) to combine photodynamic antitumor activity with cancer-specific inhibition of collagen-crosslinking enzymes (lysyl oxidase (LOX) family) for activatable cancer photo-immunotherapy. SPNcb is self-assembled from an amphiphilic semiconducting polymer conjugated with a LOX inhibitor (β-aminopropionitrile, BAPN) via a cancer biomarker (cathepsin B, CatB)-cleavable segment. BAPN can be exclusively activated to inhibit LOX activity in the presence of the tumor-overexpressed CatB, thus blocking collagen crosslinking and decreasing ECM stiffness. Such an ECM nanoremodeler synergizes immunogenic phototherapy and checkpoint blockade immunotherapy to improve the tumor infiltration of cytotoxic T cells, inhibiting tumor growth and metastasis.     

Acid-activatible micelleplex delivering siRNA-PD-L1 for improved cancer immunotherapy of CDK4/6 inhibition

Cyclin-dependent kinases 4 and 6 inhibitors(CDK4/6i) have been demonstrated to trigger antitumor immunity for tumor regression. However, the therapeutic performance of CDK4/6i-meadiated cancer immunotherapy was impaired by the immunosuppressive tumor microenvironment(ITM) due to overexpression of programmed death ligand 1(PD-L1) on the surface of cancer cell membrane. To improve the immunotherapeutic performance of CDK4/6i, we herein developed endosomal acidactivatable micelleplex for si RNA delivery and PD-L1 knockdown in the tumor cells in vitro and in vivo. We further demonstrated that the combination of PD-L1 knockdown and CDK4/6 inhibition facilitated intratumoral infiltration of cytotoxic T lymphocytes(CTLs), and elicited protective immune response and efficiently suppressed tumor growth in vivo. This study revealed the importance of molecular design of the micelleplex for highly efficient si RNA delivery, which might provide a novel insight for RNAi-based cancer immunotherapy.     

In situ Engineering of Tumor-Associated Macrophages via a Nanodrug-Delivering-Drug (β-Elemene@Stanene) Strategy for Enhanced Cancer Chemo-Immunotherapy

Tumor-associated macrophages (TAMs) play a critical role in the immunosuppressive solid tumor microenvironment (TME), yet in situ engineering of TAMs for enhanced tumor immunotherapy remains a significant challenge in translational immuno-oncology. Here, we report an innovative nanodrug-delivering-drug (STNSP@ELE) strategy that leverages two-dimensional (2D) stanene-based nanosheets (STNSP) and β-Elemene (ELE), a small-molecule anticancer drug, to overcome TAM-mediated immunosuppression and improve chemo-immunotherapy. Our results demonstrate that both STNSP and ELE are capable of polarizing the tumor-supportive M2-like TAMs into a tumor-suppressive M1-like phenotype, which acts with the ELE chemotherapeutic to boost antitumor responses. In vivo mouse studies demonstrate that STNSP@ELE treatment can reprogram the immunosuppressive TME by significantly increasing the intratumoral ratio of M1/M2-like TAMs, enhancing the population of CD4⁺ and CD8⁺ T lymphocytes and mature dendritic cells, and elevating the expression of immunostimulatory cytokines in B16F10 melanomas, thereby promoting a robust antitumor response. Our study not only demonstrates that the STNSP@ELE chemo-immunotherapeutic nanoplatform has immune-modulatory capabilities that can overcome TAM-mediated immunosuppression in solid tumors, but also highlights the promise of this nanodrug-delivering-drug strategy in developing other nano-immunotherapeutics and treating various types of immunosuppressive tumors.     

Bioorthogonal Reaction-Mediated Tumor-Selective Delivery of CRISPR/Cas9 System for Dual-Targeted Cancer Immunotherapy

CRISPR system-assisted immunotherapy is an attractive option in cancer therapy. However, its efficacy is still less than expected due to the limitations in delivering the CRISPR system to target cancer cells. Here, we report a new CRISPR/Cas9 tumor-targeting delivery strategy based on bioorthogonal reactions for dual-targeted cancer immunotherapy. First, selective in vivo metabolic labeling of cancer and activation of the cGAS-STING pathway was achieved simultaneously through tumor microenvironment (TME)-biodegradable hollow manganese dioxide (H-MnO₂) nano-platform. Subsequently, CRISPR/Cas9 system-loaded liposome was accumulated within the modified tumor tissue through in vivo click chemistry, resulting in the loss of protein tyrosine phosphatase N2 (PTPN2) and further sensitizing tumors to immunotherapy. Overall, our strategy provides a modular platform for precise gene editing in vivo and exhibits potent antitumor response by boosting innate and adaptive antitumor immunity.