TIP30在胰腺中的表达及对胰腺癌细胞生物学特性的影响

目的:探讨抑癌基因TIP30在胰腺中的表达情况,并研究其对胰腺癌细胞生物学特性的影响,为TIP30在胰腺癌基因治疗中的应用提供依据.方法:采用免疫组织化学检测12例正常胰腺组织和106例胰腺导管腺癌组织中TIP30的表达情况;RT-PCR和Western blot检测TIP30基因在三种主要胰腺癌细胞系中的表达情况;根据结果构建相应慢病毒载体转染胰腺癌细胞,检测TIP30对细胞增殖能力,克隆形成能力和成瘤能力的影响.结果:TIP30在胰腺导管腺癌组织中表达缺失率为49.1％,正常组织中的缺失率为0％,差异有统计学意义(P＜0.01);在不同胰腺癌细胞系中,内源性TIP30也存在差异化表达,Capan-2细胞系中表达量最高,SW1990细胞系其次,PANC-1细胞系中表达量最低;抑制Capan-2细胞内源性TIP30表达可以增强肿瘤细胞增殖、克隆形成和成瘤能力,使PANC-1细胞中TIP30过表达,可以抑制肿瘤细胞增殖、克隆形成和成瘤能力.结论:组织表达分析和细胞功能试验都证实TIP30作为抑癌基因在胰腺癌发生发展中起重要作用,为胰腺癌的治疗提供新的研究方向.     

人胰腺癌细胞再增殖体外模型的建立

目的:细胞再增殖是导致胰腺癌放化疗失败的主要原因之一,但缺乏合适的用于研究胰腺癌再增殖的细胞模型。本研究拟建立简便、实用的胰腺癌细胞再增殖体外模型。方法:表达绿色荧光蛋白-荧光素酶(GFP-Luc)的慢病毒感染人胰腺癌细胞,经嘌呤霉素筛选,用荧光显微镜和流式细胞仪观察双标记细胞GFP表达情况,用生物成像检测双标记细胞Luc活性及分析细胞数量与Luc活性之间的关系。以X-线照射胰腺癌细胞制备饲养细胞,以相应的双标记肿瘤细胞为报告细胞进行共培养。对共培养细胞进行荧光显微镜观察和生物成像,以判断饲养细胞对报告细胞的生长促进作用。结果:通过表达GFP-Luc的慢病毒感染获得双标记人胰腺癌细胞,经荧光显微术、流式细胞术和生物成像术证实这些双标记的人胰腺癌细胞能有效地表达GFP和Luc活性,可作为报告细胞用于建立人胰腺癌再增殖细胞模型。将经X-线照射的饲养细胞和相应的报告细胞共培养,经荧光显微镜观察和生物成像分析,结果显示X-线照射过的饲养细胞对报告细胞的生长具有显著的促进作用。结论:成功建立了简便、实用的人胰腺癌再增殖体外模型,该模型能很好地模拟人体内胰腺癌细胞再增殖过程,为进一步研究胰腺癌细胞再增殖的分子机制提供了新的技术手段。     

胆固醇代谢重编程在胰腺癌中的作用及靶向胆固醇代谢药物的应用

胰腺癌起病隐匿，缺乏有效的治疗方法，是预后最差的实体肿瘤之一，亟需探索新的治疗方向。代谢重编程是肿瘤的重要标志之一，处于恶劣肿瘤微环境中的胰腺癌细胞为了维持旺盛的代谢需求将胆固醇代谢全面上调，肿瘤相关成纤维细胞为癌细胞提供大量的脂质。胆固醇代谢重编程涉及胆固醇的合成、摄取、酯化、以及胆固醇相关代谢产物的一系列调整，与胰腺癌的增殖、侵袭、转移、耐药、免疫抑制等表型密切相关，抑制胆固醇代谢具有明显的抗肿瘤作用。本文从胰腺癌的高危因素、肿瘤相关成纤维细胞与癌细胞间的能量交互、细胞胆固醇代谢关键靶点的作用机制及其靶向药物，综述了胰腺癌胆固醇代谢的复杂性与重要性。胆固醇代谢具有严格的调控与反馈机制，单一靶点药物在临床应用中的效果并不明确，因此胆固醇代谢的多靶点疗法是胰腺癌治疗的新方向。     

肿瘤微环境代谢对T细胞的影响

肿瘤微环境(tumor microenvironment,TME)包含肿瘤组织中各种细胞如肿瘤细胞、免疫细胞、成纤维细胞等,还包含这些细胞分泌的各种可溶性因子,以及代谢底物(如葡萄糖)和代谢产物(如乳酸)等等。由于肿瘤细胞和免疫细胞对营养共同的大量需求,肿瘤微环境中的肿瘤细胞和T细胞之间会发生营养代谢竞争。这种微环境中的营养竞争已经被证明和抗肿瘤免疫抑制的发生密切相关,但同时这种关联也是复杂的和多因素的。肿瘤微环境中的共抑制分子的表达、葡萄糖的竞争、氨基酸的竞争、氧的竞争以及乳酸的分泌等等,共同成为了免疫抑制表型的重要促进因素。这些研究也给肿瘤的治疗提供了新的方向。本文从肿瘤细胞和T细胞代谢重编程出发,介绍不同的微环境因素对T细胞的影响。     

异质性干细胞增殖过程中的熵变化

干细胞在多细胞生物体内广泛存在,其增殖过程在生命体的生长、发育、衰老、组织修复过程中起着重要作用。正常组织中的细胞增殖过程受到严格的控制,干细胞的异常增殖与恶性肿瘤、肥胖症、再生障碍性贫血等疾病有密切关系。生命体内异质性细胞的增殖过程是复杂的动力系统行为,干细胞异常增殖过程伴随细胞的可塑性变化和细胞间相互作用的再平衡过程,如何对这一过程进行定量描述是重要的研究课题。本文构建包含细胞的增殖分化指标和异常增殖性指标异质性的干细胞增殖模型,通过所建立的模型研究由于微环境变化引起的细胞异常增殖过程的熵变化,建立不同增殖条件下的系统熵变化与宏观动力学和系统参数之间的关系。结果表明,在细胞微环境变化引起异常增殖和恢复的过程中,系统的熵与细胞数量之间存在对应关系,而与微环境变化的路径无关。 此外,熵对细胞数量的依赖关系在异常增殖和恢复阶段表现出不同的行为,显示了生物过程的微观不可逆性。本文从物理学的角度对细胞异常增殖过程中熵变化与细胞数量变化的动力学给出定量刻画,为定量描述异质性干细胞增殖过程给出新的研究思路。     

黏着斑激酶与肿瘤微环境

黏着斑激酶（focal adhesion kinase, FAK）是一种胞质非受体酪氨酸激酶。FAK和肿瘤密切相关,在多种癌细胞中高表达,促进癌细胞的发生、生长、存活、增殖、粘附、转移和侵袭以及血管生成等过程。肿瘤微环境包括肿瘤细胞、周围血管、免疫细胞、纤维母细胞、内皮细胞、信号分子和细胞外基质,它对癌症的发展和恶化具有重要作用。肿瘤细胞可以通过分泌细胞外信号影响微环境,使其有利于肿瘤生存和发展|肿瘤微环境中的基质细胞能通过产生趋化因子、基质降解酶和生长因子促进肿瘤侵袭和转移。本文综述肿瘤微环境在癌症发生发展过程中的作用及FAK在肿瘤微环境中的调控作用,为肿瘤疾病的治疗提供新思路。     

肿瘤相关成纤维细胞促进肿瘤侵袭转移的作用机制

肿瘤相关成纤维细胞(cancer-associated fibroblasts,CAFs)是肿瘤微环境中最主要的成分之一,在肿瘤的发生发展中发挥着必不可少的作用。骨髓和脂肪的局部组织固有成纤维细胞及间充质干细胞是CAFs来源的主要前体细胞。大量研究表明,CAFs并不作为单独细胞在肿瘤周围存在,而是和肿瘤细胞相互作用,促进肿瘤的生长与存活并维持其恶性倾向。肿瘤细胞可以影响CAFs前体的招募,并诱导正常成纤维细胞活化为CAFs;同时,CAFs可以分泌多种细胞因子、生长因子和细胞外基质蛋白质,促进肿瘤细胞的增殖、耐药及侵袭转移,从而影响肿瘤的预后。CAFs还参与血管淋巴管的生成、细胞外基质重塑、免疫抑制以及肿瘤细胞上皮间质转化等有利于肿瘤发生发展的外源性途径,为肿瘤细胞提供了一个良好的微环境。大量研究显示,研发靶向CAFs的药物可以中断其与肿瘤细胞之间的联系,从而抑制肿瘤的生长和转移。因此,深入了解CAFs促肿瘤的作用机制将有利于肿瘤治疗新靶点的发现。本文将对CAFs促进肿瘤侵袭转移的作用机制加以综述。     

间充质干细胞在炎症性疾病治疗中的基础研究和临床应用

间充质干细胞/基质细胞(mesenchymal stem/stromal cells, MSCs),由于其独特的免疫调节能力而备受关注。在治疗克罗恩病、移植物抗宿主病、系统性红斑狼疮以及器官纤维化等炎症性疾病的临床研究和应用中, MSCs均被报道可以抑制炎症,缓解疾病进展,展现出了良好的药用前景。MSCs调控炎症微环境、改善疾病的方式有很多,总体而言,在强烈炎症因子的刺激下, MSCs可以重塑组织微环境,使之向有利于再生和免疫正常化的方向转变。机制上,在炎症因子的刺激下,MSCs通过产生免疫抑制分子、生长因子、趋化因子、补体以及代谢产物等,调控多种免疫细胞的迁移、增殖和活化等生物过程以达到调控炎症微环境的目的。更新的报道甚至提出凋亡的MSCs也能发挥免疫抑制的功能。此外, MSCs的免疫调节能力受炎症因子调控,不是与生俱来又一成不变的,因此,依据微环境中炎症因子的种类、水平, MSCs的免疫调节功能也会发生变化。该文主要总结了近年来人们对MSCs免疫调节机制、MSCs与炎症微环境相互作用的理解以及应用MSCs治疗炎症性疾病的临床现状。     

肿瘤相关成纤维细胞与成纤维细胞活化蛋白在肿瘤免疫治疗中的研究进展

除了依赖于肿瘤细胞自身的恶性增殖以外,肿瘤的发生和发展还依赖于肿瘤细胞与肿瘤间质微环境的相互作用。肿瘤间质中存在的肿瘤相关成纤维细胞（tumor-associatedfibroblasts,TAF）能够诱导免疫抑制,是肿瘤免疫治疗中的一大障碍。在TAF上存在一种成纤维细胞激活蛋白（fibroblast activationprotein,FAP）,它在细胞表面发挥作用,是一种膜丝氨酸肽酶,是Ⅱ型丝氨酸蛋白酶家族成员之一,具有二肽肽酶及胶原酶活性,在肿瘤微环境中表达FAP的肿瘤相关成纤维细胞是最早被鉴定的一种肿瘤间质细胞类型。它由肿瘤问质中的成纤维细胞与癌细胞相互作用而活化,是肿瘤微环境中最主要的宿主细胞,具有促进肿瘤细胞生长、侵袭及免疫抑制的作用,而且基因组稳定不易耐药,有望成为肿瘤免疫治疗的新靶标。就靶向TAF和FAP在肿瘤免疫治疗中的研究做一综述,为基于肿瘤间质微环境的免疫治疗提供参考。     

胰腺癌原位种植瘤中VEGF-C的器官差异表达和作用

目的 研究胰腺癌裸鼠原位种植瘤自发性淋巴结转移模型中VEGF-C表达的器官差异,以及VEGF-C反义寡核苷酸对不同生长部位胰腺癌细胞生长、凋亡能力的影响。方法 建立人胰腺癌细胞株PANC-1裸鼠原位种植瘤自发性淋巴结转移模型,分离、原代培养原发灶和自发性淋巴结转移灶中的胰腺癌细胞,并应用荧光定量PCR、MTT、流式细胞术检测VEGF-C反义寡核苷酸转染对原发胰腺癌细胞和淋巴结转移的胰腺癌细胞各自生长特性、凋亡能力的影响。结果 淋巴结转移胰腺癌细胞VEGF-C的mRNA表达水平显著高于原发灶胰腺癌细胞（P〈0.05）。VEGF-C反义核苷酸抑制胰腺癌细胞VEGF-C的表达后,淋巴结转移灶中胰腺癌细胞生长抑制率、凋亡率均显著提高（P〈0.01）,而原发灶中胰腺癌细胞无明显影响（P〉0.05）。结论 VEGF-C反义寡核苷酸能显著抑制淋巴结转移灶中胰腺癌细胞生长、促进凋亡,但对原发灶胰腺癌细胞无影响;VEGF-C基因的表达和作用存在器官差异性。     

Neutrophil-Derived Proteases in the Microenvironment of Pancreatic Cancer -Active Players in Tumor Progression

A hallmark of pancreatic ductal adenocarcinoma (PDAC) is the fibro-inflammatory microenvironment, consisting of activated pancreatic stellate cells, extracellular matrix proteins, and a variety of inflammatory cells, such as T cells, macrophages, or neutrophils. Tumor-infiltrating immune cells, which are found in nearly all cancers, including PDAC, often fail to eliminate the tumor, but conversely can promote its progression by altering the tumor microenvironment. Pancreatic cancer cells are able to attract polymorphonuclear neutrophils (PMN) via tumor secreted chemokines and in human PDAC, PMN infiltrates can be observed in the vicinity of tumor cells and in the desmoplastic tumor stroma, which correlate with undifferentiated tumor growth and poor prognosis. The behavior of tumor-infiltrating neutrophils in the tumor micromilieu is not yet understood at a mechanistic level. It has been shown that PMN have the potential to kill tumor cells, either directly or by antibody-dependent cell-mediated cytotoxicity, but on the other side various adverse effects of PMN, such as promotion of aggressive tumor growth with epithelial-to-mesenchymal transition and increased metastatic potential, have been described. Recent therapeutic approaches for PDAC focus not only the tumor cell itself, but also elements of the tumor microenvironment. Therefore, the role of PMN and their derived products (e.g. cytokines, proteases) as a new vein for a therapeutic target should be critically evaluated in this context. This review summarizes the current understanding of the interplay between proteases of tumor-infiltrating neutrophils and pancreatic tumor cells and elements of the desmoplastic stroma.     

Oncolytic virotherapy for pancreatic ductal adenocarcinoma: A glimmer of hope after years of disappointment?

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and highly lethal malignancies. Existing therapeutic interventions have so far been unsuccessful in improving prognosis, and survival remains very poor. Oncolytic virotherapy represents a promising, yet not fully explored, alternative strategy for the treatment of PDAC. Oncolytic viruses (OVs) infect, replicate within and lyse tumor cells specifically and stimulate antitumor immune responses. Multiple challenges have hampered the efficacy of oncolytic virotherapy for PDAC, the most significant being the desmoplastic and immunosuppressive pancreatic tumor microenvironment (TME). The TME limits the access of therapeutic drugs and the infiltration of effector T cells and natural killer (NK) cells into the tumor mass. Additionally, cancer cells promote the secretion of immunosuppressive factors and develop mechanisms to evade the host immune system. Because of their oncolytic and immune-stimulating properties, OVs are the ideal candidates for counteracting the pancreatic immunosuppressive TME and for designing combination therapies that can be clinically exploited in clinical trials that seek to improve the prognosis of PDAC.     

Fibroblast heterogeneity in pancreatic ductal adenocarcinoma: Perspectives in immunotherapy

Cancer-associated fibroblasts (CAFs), the key component in pancreatic tumor microenvironment (TME), originate from many sources and are naturally heterogeneous in phenotype and function. Numerous studies have identified their crucial role in promoting tumorigenesis through many routes including fostering cancer proliferation, angiogenesis, invasion, and metastasis. Conversely, research also indicates that subsets of CAFs express anti-tumor activity. These dual effects reflect the complexity of CAF heterogeneity and their interactions with other cells and factors in pancreatic TME. A critical component in this environment is infiltrated immune cells and immune mediators, which can communicate with CAFs. The crosstalk occurs via the production of various cytokines, chemokines, and other mediators and shapes the immunological state in TME. Comprehensive studies of the crosstalk between CAFs and tumor immune environment, particularly internal mechanisms interlinking CAFs and immune effectors, may provide new approaches for pancreatic ductal adenocarcinoma (PDAC) treatments. In this review, we explore the characteristics of CAFs, describe the interplay among CAFs, infiltrated immune cells, other mediators, and provide an overview of recent CAF-target therapies, their limitations, and potential research directions in CAF in the context of PDAC.     

Targeting the metabolism and immune system in pancreatic ductal adenocarcinoma: Insights and future directions

Pancreatic cancer, specifically pancreatic ductal adenocarcinoma (PDAC), presents a challenging landscape due to its complex nature and the highly immunosuppressive tumor microenvironment (TME). This immunosuppression severely limits the effectiveness of immune-based therapies. Studies have revealed the critical role of immunometabolism in shaping the TME and influencing PDAC progression. Genetic alterations, lysosomal dysfunction, gut microbiome dysbiosis, and altered metabolic pathways have been shown to modulate immunometabolism in PDAC. These metabolic alterations can significantly impact immune cell functions, including T-cells, myeloid-derived suppressor cells (MDSCs), and macrophages, evading anti-tumor immunity. Advances in immunotherapy offer promising avenues for overcoming immunosuppressive TME and enhancing patient outcomes. This review highlights the challenges and opportunities for future research in this evolving field. By exploring the connections between immunometabolism, genetic alterations, and the microbiome in PDAC, it is possible to tailor novel approaches capable of improving immunotherapy outcomes and addressing the limitations posed by immunosuppressive TME. Ultimately, these insights may pave the way for improved treatment options and better outcomes for PDAC patients.     

Inhibition of DCLK1 kinase reverses epithelial-mesenchymal transition and restores T-cell activity in pancreatic ductal adenocarcinoma

Immunotherapy has recently become a promising cancer therapy with extensive applications of immune checkpoint inhibitors (ICIs). However, pancreatic ductal adenocarcinoma (PDAC) appears to be unresponsive to immunotherapy due to the immunosuppressive microenvironment. Recent studies showed that cancer stem cell marker DCLK1 promoted the initiation and development of PDAC. Nevertheless, the mechanism driving this process remains unclear. Here, by performing gain-of-function investigations in PDAC cell lines, we demonstrate that both DCLK1 long (DCLK1-iso1, DCLK1-AS) and short (DCLK1-iso4, DCLK1-BL) isoforms can efficiently activate EMT leading to tumor migration and invasion. Consistent with experiments in vitro, bioinformatic analysis demonstrates that DCLK1 may act as a driver of EMT activation in PDAC. Further analysis showed that EMT was associated with an immunosuppressive microenvironment, which includes more immunosuppressive cells and chemokines, and patients with a higher EMT score were less sensitive to immune checkpoint inhibitors according to the TIDE (Tumor Immune Dysfunction and Exclusion) algorithm. Multiplexed immunofluorescence results demonstrated the close correlation between DCLK1, EMT and immunosuppression in PDAC patients. The findings were further confirmed in vivo reflected by decreased CD4+, CD8+ T cells and increased M2 macrophages as well as E-cad loss in DCLK1-overexpressing subcutaneous tumors. Importantly, the highly-specific DCLK1 inhibitor (DCLK1-IN-1) was able to effectively block EMT process and restore T-cell activity. Altogether, our data demonstrate that DCLK1 is strongly associated with tumor immune escape in PDAC and inhibiting DCLK1 kinase activity may be a promising therapeutic modality.     

EMT——联系免疫炎症反应与肿瘤发生发展的桥梁

恶性肿瘤严重威胁着人们的健康,肿瘤细胞侵袭和转移是恶性肿瘤患者死亡的重要原因。研究表明,肿瘤恶性转化的过程需要适宜的微环境,即肿瘤微环境,肿瘤细胞在肿瘤微环境中受到细胞因子、蛋白酶等多种因素的影响,发生免疫炎性反应、上皮间质转化（EMT）、刺激肿瘤血管形成等一系列病理生理改变,从而促进肿瘤的侵袭和转移。本文概述了机体免疫炎性反应、EMT和肿瘤微环境在肿瘤中的相互联系及其作用,以期为深入研究肿瘤发生发展的分子机制提供新的思路,并为肿瘤的分子靶向治疗提供理论依据。     

PKCι regulates the expression of PDL1 through multiple pathways to modulate immune suppression of pancreatic cancer cells

To investigate the impact of oncogenic protein kinase C isoform ι (PKCι) on the microenvironment and the immunogenic properties of pancreatic tumors, we prohibit PKCι activity in various pancreatic ductal adenocarcinoma (PDAC) cell lines and co-culture them with human natural killer NK92 cells. The results demonstrate that PKCι suppression enhances the susceptibility of PDAC to NK cytotoxicity and promotes the degranulation and cytolytic activity of co-cultured NK92 cells. Mechanistic studies pinpoint that downstream of KRAS, both YAP1 and STAT3 are recruited by oncogenic PKCι to elevate the expression of PDL1, contributing to constitute an immune suppressive microenvironment in PDAC. Co-culture with NK92 further induces PDL1 upregulation via STAT3 to stimulate immune escape of PDAC cells. Subsequently, inhibition of PKCι in PDAC alleviates the immune suppression and enhances the cytotoxicity of NK92 towards PDAC through restraining PDL1 overexpression. Combined with PD1/PDL1 blocker, PKCι inhibitor remarkably elevates the cytotoxicity of NK92 against PDAC cells in vitro, establishing PKCι inhibitor as a promising candidate for boosting the immunotherapy of PDAC.     

From tumor microenvironment communicants to biomarker discovery: Selectively packaged extracellular vesicular cargoes in pancreatic cancer

Virtually all cells release various types of vesicles into the extracellular environment. These extracellular vesicles (EVs) transport molecular cargoes, performing as communicants for information exchange both within the tumor microenvironment (TME) and to distant organs. Thus, understanding the selective packaging of EV cargoes and the mechanistic impact of those cargoes - including metabolites, lipids, proteins, and/or nucleic acids - offers an opportunity to increase our knowledge of cancer biology and identify EV cargoes that might serve as cancer biomarkers in blood, saliva, or urine samples. In this review, we collect and organize recent advances in this field with an emphasis on pancreatic cancer (pancreatic adenocarcinoma, PDAC) and the concept that cells selectively package cargo into EVs. These studies demonstrate PDAC EV cargoes signal to reprogram and remodel the TME and impact distant organs. EV cargoes identified as potential PDAC diagnostic and prognostic biomarkers are summarized.