树突状细胞疫苗在肿瘤临床治疗中的应用

树突状细胞(Dendritic cell，DC)是目前发现的功能最强大的抗原提呈细胞，其功能独特之处在于能捕获、提呈肿瘤抗原并激活初始型T细胞，从而引发一系列的肿瘤抗原特异性的免疫应答。DC疫苗在众多的动物肿瘤模型的治疗中已取得了显著的效果。近年来，DC疫苗的临床I、Ⅱ期研究也取得了一定的进展。本文就近几年来DC细胞在肿瘤免疫治疗中的临床应用研究做一回顾。     

Dendritic Cell-Based Vaccines in Cancer

Therapeutic vaccines that can activate the immune system to destroy malignancies hold the promise of a low-toxicity, precisely targeted anticancer treatment modality. Because dendritic cells (DCs) are central to the activation of antigen-specific immune responses, DCs loaded with tumor antigens are of considerable interest as therapeutic vaccines. Preclinical studies have demonstrated the potency of DC-based immunizations in promoting tumor rejection. Continued preclinical and clinical studies are assessing a number of important parameters regarding the formulation and administration regimen of DC-based vaccines and have provided support for phase I and II studies. Thus far, DC-mediated immunizations have been well tolerated, with few toxicities reported. Tumor regression has been reported in up to 30% of patients, particularly with immunologically sensitive tumors such as melanoma. Biologic activity, measured as activation of antigen-specific T cells, is reported in up to 100% of patients immunized against potent recall antigens, such as tetanus toxoid, and up to 30% of those immunized against tumor antigens. Current clinical trials are increasingly testing DC-based vaccines in patients with minimal residual disease, such as following attempted curative surgery or following high-dose chemotherapy and stem-cell support where clinical benefit is likely to be the greatest. Newer strategies are focusing on further modifications to DCs to increase their immuno stimulatory potency. These include newer methods of antigen loading, better techniques for DC maturation, strategies to enhance polarization of DCs to ensure the induction of T helper cell type 1 immune responses, and the administration of adjunctive cytokines to augment the immune response following immunization.     

树突状细胞疫苗的临床研究进展

 树突状细胞(Dendritic Cells，DC)最先由Steinman在1973年描述，是体内最活跃、功能最强大的专职抗原提呈细胞。DC广泛存在于淋巴组织和非淋巴组织中，在血细胞中占单个核细胞总数的0．5%～1％。在大多数组织中，DC以不成熟形式存在，其MHC、共刺激分子和黏附分子的表达低，不能够有效地捕捉抗原和激活T细胞。而多种细胞因子能够在体外培养中刺激外周血、骨髓和脐血中DC前体，如在GM-CSF、IL-4和TNF-a的作用下，产生成熟的树突状细胞。     

Development and Clinical Evaluation of Dendritic Cell Vaccines or HPV Related Cervical Cancer - a Feasibility Study

Human papillomavirus infection (HPV) and HPV related immune perturbation play important roles in thedevelopment of cervical cancer. Since mature dendritic cells (DCs) are potent antigen-presenting cells (APC),they could be primed by HPV antigens against cervical cancers. In this study we were able to generate, maintainand characterize, both phenotypically and functionally, patient specific dendritic cells in vitro. A randomizedPhase I trial with three arms - saline control (arm I), unprimed mature DC (arm II) and autologous tumor lysateprimed mature DC (arm III) and fourteen patients was conducted. According to WHO criteria, grade 0 or gradeone toxicity was observed in three patients. One patient who received tumor lysate primed dendritic cells andlater cis-platin chemotherapy showed a complete clinical response of her large metastatic disease and remaineddisease free for more than 72 months. Our findings indicate that DC vaccines hold promise as adjuvant sforcervical cancer treatment and further studies to improve their efficacy need to be conducted.     

冻融抗原冲击致敏的树突状细胞对结肠癌小鼠的治疗作用

目的 :研究冻融的肿瘤抗原冲击致敏的骨髓来源的树突状细胞 (DC)对结肠癌小鼠是否具有治疗作用。方法 :用小鼠结肠癌细胞株C2 6冻融抗原体外冲击致敏BALB/c小鼠骨髓来源的DC ,观察其体外刺激荷瘤小鼠脾细胞增殖的能力及其诱导的CTL对C2 6肿瘤细胞的杀伤活性 ;体内以 3× 10 5DC /只一次或多次接种于已荷瘤 10d结肠癌的小鼠同侧腹股沟皮下 ,观察抗原冲击的DC对肿瘤生长的抑制作用以及对荷瘤小鼠生存期的影响。结果 :体外抗原冲击致敏的DC能显著刺激荷瘤小鼠脾脏T细胞增殖 ,其诱导的CTL对C2 6肿瘤细胞具有显著的杀伤作用 ,在效靶比为 10∶1,5∶1,2 .5∶1时其杀伤率分别 88 1% ,71.4%和 5 0 .0 % ;抗原冲击致敏的DC体内多次皮下免疫后对肿瘤的生长具有显著的抑制作用 ,能显著延长荷瘤小鼠的生存期。一次性DC体内免疫接种对荷瘤小鼠的治疗作用不明显。结论 :肿瘤细胞冻融抗原体外冲击致敏的DC多次皮下免疫对结肠癌小鼠具有显著的治疗效果     

DC肿瘤融合瘤苗抗肿瘤效应的实验研究

目的:观察DC与肿瘤细胞融合后的瘤苗体内诱导的抗肿瘤免疫应答以及对荷瘤小鼠的治疗作用.方法:应用免疫磁珠分选和贴壁培养方法收集融合细胞,应用3H-TdR掺入法、4h51Cr释放法观察T细胞增殖反应的能力和CTL活性,并观察瘤苗对荷瘤小鼠保护性免疫反应和免疫治疗作用.结果:DC肿瘤融合瘤苗具有强烈的激活T细胞增殖和抗原提呈的能力,在体外、体内诱导出更强的特异CTL细胞毒活性,使免疫小鼠产生一定的免疫保护作用,抵抗Hepa1-6肝癌细胞的再次攻击,使治疗的小鼠肿瘤的生长明显缓慢,具有更明显的治疗作用.结论:DC与肿瘤细胞融合后进行体内免疫和治疗,能诱导出显著的抗肿瘤免疫反应,为DC介导的肿瘤免疫治疗开辟了新的途径.     

Vaccines for the Treatment of Non‐Small Cell Lung Cancer: A Renewed Anticancer Strategy

Carcinoma of the lung is the leading cause of cancer death worldwide, with non‐small cell lung cancer (NSCLC) constituting about 85% of all new diagnoses. Standard approaches for each NSCLC stage have reached a plateau in effectiveness. A variety of novel approaches are now being investigated to improve the outcome of this disease. Despite decades of research, no specific active cancer vaccine has, to date, been approved for NSCLC therapy; nevertheless, vaccine therapy has recently re‐emerged as a potential therapeutic approach. In particular, several new paradigms have stemmed from recent clinical findings both in the use of combination therapy approaches with more sophisticated specific vaccines and in clinical trial design and endpoint analyses. Several vaccine therapies have been investigated in NSCLC, including in the early and advanced disease stages. The best results appear to be in the adjuvant settings and in locally advanced NSCLC. In fact, in these two settings, phase III randomized trials are ongoing evaluating the melanoma‐associated antigen A3 vaccine and the liposomal BLP25 vaccine. This paper reviews the main clinical trials involving several different cancer vaccines employed in the treatment of early and advanced stage NSCLC, focusing on those in advanced stages of development.     

过氧化氢促进结肠癌细胞诱导的内皮细胞迁移

目的探讨过氧化氢在大肠癌进展过程中的作用。方法不同浓度的过氧化氢分别与结肠癌细胞系LS174T和HCT8共孵育，24h后再与内皮细胞系ECV304共培养，观察不同浓度过氧化氢作用下结肠癌细胞诱导的内皮细胞迁移数目的差异；同时应用免疫组化及双抗体夹心酶联免疫法观察癌细胞及其培养液中血管内皮生长因子的表达情况。结果当过氧化氢浓度≤10—5mol／L时，不同程度地促进内皮细胞的迁移，当过氧化氢浓度为10^-5 mol／L时，促进作用最强（P〈0．05）。免疫组化及双抗体夹心酶联免疫法显示，在过氧化氢的作用下，2种癌细胞中血管内皮生长因子表达增强。结论适当浓度的过氧化氢等活性氧可能对大肠癌的进展起促进作用。     

二烯丙基二硫对人结肠癌HT-29细胞周期的阻滞作用

[目的]探讨二烯丙基二硫(DADS)对人结肠癌HT-29细胞周期的阻滞作用及其分子机制.[方法]应用MTF法及细胞计数法测量HT-29细胞生长抑制,流式细胞术检测细胞时相分布,免疫细胞法测定p21、C-myc、Cyclin E表达.[结果]MTT法显示,不同浓度DADS作用HT-29细胞12、24、48h后,细胞生长抑制率及细胞群体倍增时间呈浓度、时间依赖性增加.流式细胞仪分析,30、60pmol/LL DADS阻滞HT29细胞在G1期,与对照组相比,可使G1期细胞增加约2倍,而90、120μmol/L DADS显著地将细胞阻滞在G2/M期.免疫细胞化学分析表明在细胞周期阻滞的同时有p21wafl蛋白表达上调,Cyclin E、C-myc蛋白表达下降.[结论]DADS对HT-29细胞的抑制增殖作用可能与细胞周期阻滞有关,DADS对HT-29细胞周期阻滞的分子机制可能与调节p21wafl、Cyclin E、C-myc表达相关.     

大鼠胰腺癌细胞裂解物修饰的树突状细胞疫苗在大鼠胰腺癌模型中的抗肿瘤作用

观察经大鼠胰腺癌细胞裂解物修饰的树突状细胞（DC）疫苗对大鼠胰腺癌皮下移植瘤的免疫治疗作用。方法：大鼠胰腺癌细胞注入SD大鼠胰腺被膜下,形成肿瘤,将肿瘤取出后切碎,植入同种大鼠的腋窝皮下,建立皮下移植瘤模型;将大鼠胰腺癌细胞反复冻融4次,提取出裂解物,与SD大鼠骨髓来源的DC共培养72 h,制成DC疫苗。根据DC致敏情况分为DC疫苗组、DC组、裂解物组与对照组,分别注入大鼠皮下移植瘤体内,每组5只。每两天测一次肿瘤长径与横径,共8次,观察大鼠的生存期。结果：随着时间延长,DC疫苗组肿瘤大小呈递减趋势;DC组、裂解物组、对照组肿瘤大小呈递增趋势;DC疫苗组与对照组之间肿瘤大小差异有统计学意义（P<0.05）;DC组、裂解物组与对照组之间肿瘤大小差异无统计学意义（P>0.05）;DC疫苗组与DC组、裂解物组之间肿瘤大小差异有统计学意义（P<0.05）;DC疫苗组大鼠生存期为（55.6±9.4）d,明显长于其他各组（P<0.01）。结论：大鼠胰腺癌细胞裂解物修饰的DC疫苗有可能诱导胰腺癌皮下移植瘤大鼠产生高效的免疫应答反应,发挥抗肿瘤作用。     

非小细胞肺癌的巩固性治疗

恶性肿瘤巩固性治疗的概念,从广义上说是指肿瘤经过手术、放疗、化疗等主体治疗取得疗效后,为了达到根治或延长生存期所采取的治疗措施,巩固其治疗效果.包括术后辅助治疗、化疗取得疗效后的维持治疗,以及完成主体治疗后的巩固性治疗.要想把非小细胞肺癌变成一种可治性疾病,巩固性治疗是综合治疗中的一个至关重要的环节.非小细胞肺癌的巩固性治疗包括:巩固性化学治疗、巩固性生物治疗和巩固性中药治疗.     

卵巢癌肿瘤微环境中树突状细胞功能的研究进展

摘 要：树突状细胞是参与抗肿瘤免疫反应的始动细胞,在肿瘤的进展中扮演着不可或缺的角色,而卵巢癌患者体内树突状细胞的功能发生了诸多变化。多项研究表明,肿瘤微环境中存在免疫抑制介质,能够通过多种途径引起严重的树突状细胞功能障碍,影响着卵巢癌的进展与预后。全文对卵巢癌肿瘤微环境中树突状细胞的功能和作用作一综述,以期为改善卵巢癌的免疫治疗寻找新思路。     

肿瘤治疗新目标——肿瘤干细胞

肿瘤干细胞是肿瘤细胞的祖细胞,是肿瘤的真正种子,它们虽然仅占肿瘤细胞中极少的一部分,但具有自我更新能力和不定分化潜能,是形成不同分化程度肿瘤和肿瘤不断生长的根源,是肿瘤发生、扩散、复发等过程中的“起始细胞”或“动力细胞”。传统的化疗药物不能有效靶向作用肿瘤干细胞,开发针对肿瘤干细胞的靶向治疗,能给肿瘤治疗模式带来全新的改变,有望彻底改善患者的预后。     

交替式区域化疗治疗结肠癌肝转移

[目的]观察交替式区域化疗治疗结肠癌肝转移的近期疗效.[方法]178例结肠癌肝转移随机分成3组,交替式区域化疗组(60例)于术后2周开始,用5-Fu1500mg/(m2·d) DDP80mg/(m2·d)行肝动脉插管介入化疗,3周后以相同剂量行腹腔化疗(加生理盐水1500～2000ml注入腹腔)交替治疗.单纯腹腔化疗组(58例)于术后2周开始以相同剂量行腹腔化疗,3周后重复.单纯肝动脉介入组(60例)于术后2周开始以相同剂量行肝动脉介入化疗,3周后重复.三组均6～8个疗程,3个周期后评价疗效.[结果]交替式区域化疗组有效率43.3%,单纯腹腔化疗组有效率20.7%,单纯肝动脉介入治疗组有效率16.6%,三组差异有显著性.而且伴有癌性腹水和弥漫性肝转移者经交替式区域化疗组的有效率较其它两组高.[结论]交替式区域化疗治疗结肠癌肝转移较单一区域化疗近期疗效较好,尤其是对伴有癌性腹水和弥漫性肝转移患者.     

西达本胺对结肠癌LoVo细胞增殖抑制的体外研究

[目的]研究去乙酰化酶抑制剂（histone deacetylase inhibitor,HDACi）西达本胺（Chi-damide,实验室编号：CS055）对结肠癌细胞株LoVo体外生物学特性的影响、诱导细胞凋亡的分子机制。[方法]MTT法观察CS055（2、4、8、16、32、64μmol/L）对LoVo增殖抑制情况,流式细胞仪检测细胞周期阻滞,Westernblot检测p21、CDK4、caspase-3蛋白表达情况。[结果]CS055体外能明显抑制LoVo细胞的增殖,呈剂量、时间依赖性（P〈0.05）。CS055（16μmol/L、48h）诱导后,流式细胞仪检测示细胞被阻滞于G0/G1期,并且出现典型的亚二倍体（sub-G1）峰。CS055可明显提高p21、caspase-3蛋白的表达水平,下调CDK4蛋白的表达水平。[结论]CS055可通过诱导细胞周期阻滞及细胞凋亡而发挥体外抗结肠癌LoVo细胞增殖作用,其作用机制可能涉及对p21、CDK4、caspase-3蛋白表达的调控。     

Colonic Cell Proliferation in Normal Mucosa of Patients with Colon Cancer

Cell kinetics parameters have been analysed in colonic mucosa at different distances from a tumour in patients with colon carcinoma. Total cell number (TCN), H thymidine labelling index (TLI), mitotic index (MI), Goblet cell index (GCI) and the distribution of labelled cells along the crypt column (cell position frequency plot) were determined in well-aligned crypts. Total cell number, GCI and the labelled cell position frequency plots were similar in different samples from the same individual. A negative linear correlation between TCN and TLI was observed. The analysis of the cell position plots showed two patterns 1) with a high concentration in the bottom fifth of the crypt and 2) with frequent labelled cells at high positions. Whereas a negative correlation between overall TLI and the percent contribution to the TLI of the lowermost fifth was seen, the correlation was positive for the next 3 fifths and labelling was absent in the last part of the crypt.     

辣椒碱对结肠癌细胞自噬抑制作用的研究

[目的]研究辣椒碱对人结肠癌细胞SW480自噬的抑制作用。[方法]通过MTT法和克隆形成实验检测不同浓度辣椒碱处理的细胞增殖率,免疫荧光检测细胞自噬体的形成．Western Blot检测自噬标志物和信号通路蛋白的表达。通过蛋白组实验方法获取辣椒碱药物的相互作用蛋白。质谱技术进行蛋白鉴定及STRING数据库进行生物信息学分析。[结果]MTT结果表明100μmol／L浓度的辣椒碱能促进细胞增殖,该浓度的辣椒碱抑制了细胞自噬体的形成,抑制了LC3的活化,促进了p62的表达,提高了Akt和mTOR的磷酸化。质谱分析和STRING数据库查询发现了7个辣椒碱的相互作用蛋白,其中ATG2B与自噬存在重要联系。[结论]低浓度辣椒碱通过激活P13K-Akt信号通路及与ATG2B相互作用来抑制细胞自噬。