PD-1/PD-L1抑制剂在淋巴瘤治疗中的研究进展

近年来,肿瘤生物免疫治疗因其显著的疗效而迅速发展为肿瘤研究领域的热点。程序性死亡受体-1（programmed death-1,PD-1）与其配体（programmed death ligand-1,PD-L1）在多种肿瘤细胞中过表达,参与肿瘤的发生、发展及侵袭转移。因此,PD-1/PDL1信号通路成为了肿瘤免疫治疗的有效新靶点。目前,PD-1/PD-L1抑制剂在淋巴瘤治疗研究中取得了较好的疗效。本文将对该类药物的相关临床研究现状进行综述,旨在加深对PD-1/PD-L1信号通路的作用机制及相关抗体应用于淋巴瘤治疗的认识。      

PD-1/PD-L1在结直肠癌中的研究进展

程序性死亡受体-1 (programmed death 1,PD-1)与其配体(programmed death-ligand l,PD-L1)是目前免疫治疗中关注的焦点.PD-1与其配体PD-L1结合导致肿瘤微环境中T细胞衰竭及免疫逃逸,阻断PD-1与PD-L1结合是有效的治疗靶点.针对阻断PD-1/PD-L1通路的单克隆抗体通过美国FDA的审批己应用于临床,并已证实在恶性黑色素瘤、肺癌、膀胱癌、胃癌、霍奇金淋巴瘤、乳腺癌等多种恶性肿瘤的治疗中取得了显著效果,目前该疗法在结直肠癌(colorectal cancer,CRC)的治疗研究中也显示出了良好的疗效.本文对当前PD-1/PD-L1的分子结构、肿瘤免疫中的生物学功能和在结直肠癌微环境中的特点、临床病理分子特点、PD-1/PD-L1抑制剂治疗与耐药及预后方面的研究进展作一综述.     

PD-1/PD-L1治疗非小细胞肺癌的研究进展

程序性死亡受体-1（programmed cell death-1,PD-1）/程序性死亡配体-1（programmed cell death-ligand 1,PD-L1）信号通路与肿瘤免疫逃逸密切相关,针对PD-1/PD-L1通路的免疫检查点抑制剂为非小细胞肺癌（non-small cell lung cancer,NSCLC）患者提供了一种新的治疗选择,并且显示出良好的疗效和安全性。本文对PD-1/PD-L1抑制剂治疗NSCLC的临床研究进展进行综述。      

PD-1/PD-L1通路在乳腺癌治疗中的作用及意义

程序性死亡受体1（programmed death-1,PD-1,CD279）为共刺激受体CD28超家族成员,主要表达在活化T细胞、B细胞、单核细胞以及自然杀伤细胞表面。程序性死亡配体1（programmed death-ligand 1,PD-L1,CD274）为PD-1的一个重要配体,广泛表达于肿瘤细胞以及抗原呈递细胞（APC）表面。以PD-1/PD-L1为靶点的肿瘤免疫治疗为肿瘤治疗开辟了新的道路。PD-1通过与PD-L1和(或)PD-L2结合,抑制T细胞活化,诱导T细胞凋亡,在肿瘤免疫逃逸中起着重要的作用。目前PD-1/PD-L1信号通路成为免疫靶向治疗的新靶点,相关研究在非小细胞肺癌、晚期黑色素瘤等多种恶性肿瘤领域有重大进展,研究发现PD-L1 在多种肿瘤细胞包括乳腺癌中表达上调,提示 PD-1/PD-L1通路可能参与肿瘤的免疫逃逸。本文将针对PD-1/PD-L1通路在乳腺癌治疗中的作用及意义进行综述。     

肺癌驱动基因与PD-1/PD-L1信号通路相互作用在非小细胞肺癌发生发展中的研究进展

程序性死亡分子1(programmed death 1,PD-1)/程序性死亡分子1配体(programmed death 1 ligand,PD-L1)通路是免疫调节的重要通路,而这一通路在肿瘤组织中存在着异常激活,提示PD-1/PD-L1通路可能参与了肿瘤的免疫逃逸过程.肿瘤驱动基因在非小细胞肺癌(non-small cell lung cancer,NSCLC)的发生发展中发挥着重要的作用,而对于肿瘤免疫逃逸的建立同样具有潜在的作用,这提示肿瘤驱动基因通路与PD-1/PD-L1通路可能存在相互作用.本文将对目前关于PD-L1与主要的肺癌驱动基因表皮生长因子受体基因(epidermal growth factor receptor,EGFR)、鼠类肉瘤病毒癌基因(Kirsten rate sarcoma viral oncogene homolog,KRAS)及棘皮微管样蛋白4-间变性淋巴瘤激酶融合基因(echinoderm microtubuleassociated protein-like 4-anaplastic lymphoma kinase,EML4-ALK)之间的关系及调控进行综述,总结肺癌驱动基因及PD-1/PD-L1通路相互作用在非小细胞肺癌发生发展中的作用.     

PD-1和PD-L1在肿瘤免疫逃逸中的作用机制及临床意义

随着人们对肿瘤免疫微环境的深入研究,发现肿瘤细胞的免疫逃逸是造成肿瘤进展的关键原因,其分子机制也成为肿瘤免疫治疗研究的重点问题之一。近年研究表明程序性死亡受体-1（programmed death receptor-1,PD-1）与程序性死亡配体-1（programmed death ligand-1,PD-L1）与肿瘤发生、发展有密切联系。其中,PD-1是T细胞介导免疫反应中的重要抑制性免疫检查点,肿瘤细胞通过表达PD-L1,与肿瘤浸润淋巴细胞的PD-1结合,诱导淋巴细胞的凋亡,从而抵抗淋巴细胞的杀伤作用,最终造成肿瘤发生免疫逃逸。本文对PD-1和PD-L1在肿瘤免疫逃逸中的作用机制及在肿瘤治疗中的临床意义作一综述。     

PD-L1表达调控机制及其对抗肿瘤免疫反应的影响

肿瘤的发生是一个多因素、多步骤的过程.肿瘤细胞通过抑制机体的抗肿瘤免疫应答,实现免疫逃逸,促进肿瘤生长.肿瘤免疫逃逸的分子机制是肿瘤免疫研究的核心问题之一.在T细胞介导的免疫反应中,程序性死亡受体-1(programmed death receptor-1,PD-1)是关键的抑制性免疫检查点.肿瘤通过表达程序性死亡配体-1(programmed death ligand-1,PD-L1),可以增强PD-1抑制信号,促进肿瘤免疫逃逸.研究肿瘤细胞如何调节PD-L1表达,有助于阐明肿瘤发生免疫逃逸的分子机制.近年来的研究发现,肿瘤细胞在基因转录、转录后调节以及蛋白翻译后修饰等多个环节对PD-L1表达进行调节,并且通过调控PD-L1的表达影响抗肿瘤免疫反应.这些研究为肿瘤免疫治疗提供了新的靶点.     

PD-1/PD-L1抑制剂在外周T细胞淋巴瘤治疗中的研究进展#br#

外周T细胞淋巴瘤（peripheral T-cell lymphoma, PTCL）是一组高度异质性和侵袭性的非霍奇金淋巴瘤（non-Hodgkin’s lymphoma,NHL）。在目前化疗为主的治疗下,PTCL患者通常预后差,复发率高,因此需要积极探索新药来改善预后。肿瘤微环境（tumor microenvironment,TME）在多种肿瘤中发挥重要作用,程序性死亡［蛋白］-1（programmed death-1,PD-1）/程序性死亡［蛋白］配体-1（programmed death ligand-1,PD-L1）信号通路是参与肿瘤免疫逃逸的重要途径之一,针对PD-1/PD-L1通路的抑制剂在多种肿瘤中疗效显著,在PTCL的治疗上也有广阔的应用前景。研究表明在PTCL多种亚型中均有不同程度PD-1/PD-L1的表达,且PD-1单抗在部分亚型中疗效显著。现就PD-1/PD-L1在PTCL中的表达情况和其抑制剂的治疗进展作一综述。     

PD-L1的表达与妇科恶性肿瘤预后关系的研究进展

程序性死亡蛋白1(Programmed death protein 1,PD-1)是T细胞上主要存在的一种抑制性受体。程序性死亡配体-1(Programmed death ligand-1,PD-L1,又称B7-H1)在心、肝、肾、肺等多个器官上皮细胞和内皮细胞中广泛表达。肿瘤发生时机体内的肿瘤微环境会使浸润性T细胞高表达PD-1,同时肿瘤细胞中PD-L1的表达上调,与PD-1受体相结合,导致肿瘤微环境中PD-1通路持续开放,进而导致T细胞凋亡,肿瘤细胞则逃脱机体的免疫监视,发生肿瘤免疫逃逸。本文就PD-L1表达与妇科恶性肿瘤预后关系的研究进展进行综述。     

PD-L2在血液系统肿瘤免疫治疗中的研究进展

随着程序性死亡受体1(programmed death receptor-1,PD-1)/程序性死亡受体配体1(programmed death-ligand 1,PD-L1)抑制剂在多种实体肿瘤临床治疗中取得广泛进展,血液系统肿瘤亦拉开了免疫疗法帷幕。然而,免疫检查点阻断疗法仍存在应答率低、药物耐药和副作用严重等挑战,需要进一步寻找新的免疫治疗靶点。B7家族中的程序性死亡受体配体2(programmed death-ligand 2,PD-L2)亦可以和PD-1结合,进而抑制免疫细胞功能。此外,PD-L2可以调控肿瘤免疫逃逸,在血液系统肿瘤中的治疗潜力仍有待研究。故本文对PD-L2的生物学特征、在血液系统肿瘤中的表达及在免疫治疗中的研究进展进行简要综述,为血液系统肿瘤通过PD-1/PD-L2通路治疗提供理论依据。     

Polymorphisms in GSTM1, GSTT1 and CYP1A1 and risk of pancreatic adenocarcinoma

A prospective study of 149 unselected incident cases of pancreatic adenocarcinoma and 146 ethnically-matched controls found no associations between GSTM1 (adjusted odds ratio (AOR) 1.14), GSTT1 (AOR: 1.19) and CYP1A1 (AOR: 1.08) polymorphisms and pancreatic cancer susceptibility. Smoking and drinking status did not affect results. These polymorphisms do not appear to be important gene modifiers in pancreatic cancer.     

乙醛脱氢酶1A1基因真核表达载体的构建与鉴定

目的 构建人乙醛脱氢酶1A1（ALDH1A1）真核表达载体,并鉴定其生物学功能。方法 通过基因克隆技术获得人ALDH1A1基因cDNA序列;测序正确后,将其连接到真核细胞表达载体pEGFP-N1,构建pEGFP-N1-ALDH1A1表达载体,经酶切鉴定、测序正确后,用脂质体转染技术将pEGFP-N1-ALDH1A1表达载体转染人胃癌细胞株MKN-28细胞,利用免疫印迹法鉴定表达产物,紫外-可见分光光度法测定ALDH1A1活性的改变。结果 成功克隆到人ALDH1A1基因的全长cDNA,经测序与GeneBank序列完全一致;成功构建pEGFP-N1-ALDH1A1表达载体,经Western blotting鉴定显示ALDH1A1在MKN-28细胞中过表达,活性检测证实转染组的ALDH1A1活性较对照组明显升高。结论 成功构建并鉴定了ALDH1A1基因过表达的胃癌细胞模型,为下一步研究ALDH1A1在胃癌中作用机制打下了基础。     

PD-1/PD-L1抑制剂的困境与sPD-1/sPD-L1的标志物潜能

PD-1和PD-L1免疫检查点抑制剂是肿瘤治疗的又一个里程碑,但缺乏灵敏度和特异度高的标志物来筛选对免疫检查点抑制剂敏感的患者,导致在部分癌种和患者中有效率低;而且由于毒副作用和耐药性的存在,进一步限制了其临床应用。可溶性PD-1(sPD-1)和可溶性PD-L1(sPD-L1)是PD-1和PD-L1的溶解形式,已在多种肿瘤中被证实与肿瘤的临床病理特征、分期、疾病的严重程度、治疗敏感性及预后密切相关,可能成为免疫治疗的标志物。全文就PD-1/PD-L1抑制剂的作用机制和其在临床应用中的困境及sPD-1和sPD-L1的标志物潜能进行综述。     

Genetic polymorphism of CYP1A1, GSTM1 and GSTT1 genes in Indian oral cancer

Oral cancer ranks first among all cancers in males and is the third most common among females in India. Tobacco-derived carcinogens are involved in the development of oral cancer. Environment-gene interaction in oral carcinogenesis is well demonstrated by phase I and II enzymes that are involved in the metabolism of carcinogens. This study looked at the significance of genetic polymorphisms in CYP1A1, GSTM1 and GSTT1 genes in patients with oral cancer. The study included 98 oral cancer patients and 60 age and sex matched healthy controls. Genotypes of CYP1A1, GSTM1 and GSTT1 were determined by PCR-RFLP. GSTM1 null deletion was observed in 49% of oral cancer cases and 33% of control subjects. For GSTT1, 18% of carcinomas and 8% of controls had the null genotype. In the case of CYP1A1 m2 allele, 51% of oral cancers and 17% of normal controls, respectively, had one or both alleles with the isoleucine-->valine substitution. Digestion of the PCR products with enzyme Nco1 revealed polymorphism for CYP1A1 m2 with bands at 263 bp. There was no association between genotypes with tumor size, stage, grade, and age. Since null genotype individuals may possibly be poor detoxifiers with reduced ability to neutralise the reactive carcinogenic intermediates, they may be a high risk category. The frequency distribution of CYP1A1 m2 (Ile/val) genotypes among oral cancer patients was significantly different that from normal controls. The risk of CYP1A1 can be supported by the functional difference between presence of valine and isoleucine; valine type has higher catalytic and mutagenic activity towards benzo[a] pyrene than the isoleucine type. In conclusion, our results suggest that polymorphism in CYP1A1 m2 gene and/or GSTM1 and GSTT1 null genotype may confer an increased risk for oral cancer.     

Genetic polymorphisms of CYP1A1, GSTM1 and GSTT1 genes and lung cancer risk

Genetic polymorphisms of the genes encoding for the xenobiotic metabolizing enzymes result in individual variations in the efficiency of detoxification of environmental carcinogens, and have been extensively associated with variable risk for lung neoplasms in different ethnic and environmental backgrounds. In this study, using PCR-RFLP based assays, we investigated the distribution of genetic polymorphisms in CYP1A1, GSTM1 and GSTT1 genes in Greek lung cancer patients (N=122) and healthy controls (N=178). The frequency of CYP1A1 m1 homozygous genotype was 0.04 in patients and 0.02 in controls (detected in 4.10% of patients and in 1.69% of controls, respectively), that of GSTM1 null genotype was 0.52 in patients and 0.54 in controls, whereas those of GSTT1 null genotype was 0.17 and 0.11, in patients and controls, respectively. The GSTM1 null genotype was more frequent in adenocarcinoma, as well as in lung cancer patients with history of chronic obstructive pulmonary disease (COPD). The GSTT1 null genotype correlated with advanced age of the patients at the time of diagnosis. Three combinations of rare genotypes - in subjects carrying simultaneously deviations from the common genotype in more than one gene - were over-represented in lung cancer patients, compared to control population, and were furthermore significantly associated with history of heavy tobacco consumption in lung cancer patients. The results imply involvement of specific genotype combinations of CYP1A1, GSTM1 and GSTT1 alleles in the development of lung cancer in heavy smokers.     

谷胱苷肽S转硫酶T1、M1和P1基因多态性与结直肠癌易感性的关系

目的研究谷胱苷肽S转硫酶T1、M1和P1(GSTT1、GSTM1和GSTP1)多态性与结直肠癌易感性的关系。方法在江苏省进行了1个病例—对照研究(结直肠癌患者315例,人群对照439例),调查研究对象的生活习惯,抽取静脉血,提取白细胞DNA,以多重PCR技术检测GSTT1和GSTM1基因缺失,PCR-RFLP技术检测GSTP1基因单核苷酸多态(第104密码子A→G)。结果①在结直肠癌组和正常组GSTT1和GSTM1基因缺失频率分别为55.24%、57.31%和72.70%、73.29%、差异无显著性。②在结直肠癌组GSTP1 A/A、A/G和G/G基因型分布频度分别为57.51%、36.74%和5.75%;对照组分别为63.70%、31.05%和5.25%,2组之间差异无显著性(χ2 MH=2.993,P=0.224)。与GSTP1 A/A基因型携带者相比,G/G基因型者发生结直肠癌的危险性无显著升高,其性别、年龄、吸烟、饮酒习惯调整后的OR为1.09(95%CI:0.79~1.51)。结论GSTT1、GSTM1基因缺失型和GSTP1 G/G基因型与结直肠癌的易感性无显著相关。