PD-1/PD-L1抑制剂在晚期非小细胞肺癌中的治疗进展

程序性死亡受体1(programmed death 1,PD-1)抑制剂Pembrolizumab进入一线正式标志着免疫检查点抑制剂在晚期非小细胞肺癌(non-small cell lung cancer,NSCLC)的治疗体系中占据了重要地位.临床试验结果证实PD-1/程序性死亡配体1(programmed death ligand 1,PD-L1)抑制剂在晚期NSCLC的一线、二线和多药耐药后治疗的疗效均要优于传统的化疗.一线使用Pembrolizumab联合化疗的客观有效率(objective response rate,ORR)最高可达80%;单药Pembrolizumab的无疾病进展时间(progression-free survival,PFS)接近1年(10.3个月),死亡风险比含铂双药化疗下降40%.单药Pembrolizumab、Nivolumab和Atezolizumab用于二线的疗效同样突出,总生存时间(overall survival,OS)可至1年左右.PD-L1的表达是PD-1/PD-L1抑制剂疗效的预测因子,在晚期NSCLC中阳性(≥1%)的比例约为60%左右,组织类型间差异不大,但是目前并无检测的金标准.     

PD-1/PD-L1抑制剂在尿路上皮癌治疗中的研究进展

近年来,随着人们对肿瘤免疫生物学认识的不断深入,针对免疫检查点抑制的系统免疫疗法在尿路上皮癌领域得到了广泛的探索和临床应用。程序性细胞死亡受体1(programmed death 1,PD-1)及其配体(programmed death ligand 1,PD-L1)是机体免疫活性的重要负性调节因子,可防止正常组织和自身免疫功能的破坏。迄今为止,美国食品和药物管理局(Food and Drug Administration,FDA)已批准了可阻断PD-1(Pembrolizumab和Nivolumab)或PD-L1(Atezolizumab、Durvalumab和Avelumab)的五种免疫检查点抑制剂,根据在相关临床试验中观察到的持久的治疗反应和可控的安全性,用于局部晚期或转移性尿路上皮癌的一线或二线治疗。本文就PD-1/PD-L1抑制剂在尿路上皮癌中的研究进展作一综述。     

PD-1/PD-L1抑制剂在晚期肝细胞肝癌治疗中的研究进展

晚期原发性肝细胞肝癌(hepatocellular carcinoma,HCC)的系统治疗主要包括靶向治疗、化疗以及免疫治疗。近3年,程序性死亡受体-1(programmed death receptor-1,PD-1)/程序性死亡受体-1配体(programmed death receptor-1 ligand,PD-L1)抑制剂在晚期HCC治疗中取得突破性进展。纳武单抗(nivolumab)和帕博利珠单抗(pembrolizumab)先后被美国食品药品管理局(FDA)批准用于HCC二线治疗。多个PD-1/PD-L1抑制剂联合系统治疗的Ⅰ、Ⅱ期临床研究初步显示出较好的疗效和安全性。阿特珠单抗(atezolizumab)联合贝伐单抗一线治疗成为首个在Ⅲ期临床研究中证实优于现有标准治疗索拉非尼的全新疗法。本文就近年PD-1/PD-L1抑制剂在晚期HCC治疗中的研究进展进行概述。     

基于PD-1/PD-L1 抑制剂的肺癌免疫治疗预测标志物的研究进展

[摘要] 近年来,免疫检查点抑制剂在肺癌治疗中取得突破性进展,正迅速改变着肺癌的治疗模式,也标志着免疫治疗2.0 时代的到来。新的肿瘤治疗模式对精准医学提出更高要求,对程序性死亡受体1（programmed death 1, PD-1）/程序性死亡配体1（programmed death ligand 1, PD-L1）抑制剂预后生物标志物也在不断地探索之中,主要包括以下几个方面：PD-L1 表达水平、肿瘤基因组异质性与肿瘤新抗原、T细胞特点、肿瘤微环境以及机体整体状态等。本文将针对目前PD-1/PD-L1 抑制剂在肺癌免疫治疗中的潜在生物标志物最新临床研究进展及其研究前景进行综述。     

晚期胃癌免疫检查点PD-1/PD-L1抑制剂联合治疗的研究进展

胃癌是最为常见的恶性肿瘤之一，在中国其发病率和死亡率均较高，大多数胃癌初诊即已为晚期，预后较差，目前治疗现状仍不理想。免疫逃逸是肿瘤发生发展的一主要机制，细胞程序性死亡受体-1（programmed death-1，PD-1）及细胞程序性死亡配体（programmed death-ligand 1，PD-L1）是导致免疫逃逸的重要分子，PD-1与PD-L1结合是肿瘤细胞免疫逃逸的重要发病机制之一，特异性阻断二者结合，可达到杀灭肿瘤细胞的目的。PD-1/PD-L1抑制剂可明显改善晚期胃癌患者预后，并且PD-1/PD-L1抑制剂联合化疗、靶向治疗、放疗等可进一步提高疗效。本文就PD-1/PD-L1抑制剂联合治疗在晚期胃癌中的治疗进展进行综述。      

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抑制剂在膀胱癌新辅助治疗中的应用进展

膀胱癌是一种泌尿系统常见的肿瘤,单纯根治切除手术治疗的患者面临较高复发和转移风险,5年生存率为60~80%。在减少复发、转移和延长生存期的探索中,指南推荐以顺铂为基础的化疗作为标准新辅助治疗。但部分患者无法耐受化疗或对化疗不敏感,新辅助治疗应用率较低,未广泛开展。程序性死亡因子1(PD-1)和程序性死亡因子配体1(PD-L1)是重要的免疫检验点共抑制分子,通过抑制T细胞的激活和增殖通路参与肿瘤的免疫逃逸。近年来一批PD-1/PD-L1抑制剂被批准用于局晚期膀胱癌的一线、二线治疗,疗效及安全性得到证实,因此一些最新的研究探索将PD-1/PD-L1抑制剂运用于新辅助治疗。本文主要对近年来相关研究进行了回顾与总结,探讨PD-1/PD-L1抑制剂在膀胱癌新辅助治疗应用的前景和可能发展的方向。     

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。     

晚期胃癌免疫检查点抑制剂治疗的临床研究进展

[摘要] 晚期胃癌治疗方法有限,预后较差。2017 年,针对程序性死亡蛋白-1（programmed cell death protein-1, PD-1）和程序性死亡配体-1（programmed death ligand-1, PD-L1）的免疫检查点抑制剂获批用于晚期胃癌治疗,提示胃癌免疫治疗时代已经到来。然而,相对于肺癌,免疫检查点抑制剂尚未获批用于胃癌一、二线治疗。目前,大量胃癌免疫治疗临床试验正在进行中,其模式还在进一步优化,包括免疫联合化疗、免疫检查点抑制剂联合其他免疫治疗及新型免疫检查点抑制剂的应用等,同时寻找合适的肿瘤标志物,筛选优势人群用于胃癌精准免疫治疗。本文着重讨论晚期胃癌免疫检查点抑制剂治疗的临床研究最新进展。     

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。     

HDAC1-mSin3a-NCOR1, Dnmt3b-HDAC1-Egr1 and Dnmt1-PCNA-UHRF1-G9a regulate the NY-ESO1 gene expression

The NY-ESO1 gene is a cancer/testis antigen considered to be suitable target for the immunotherapy of human malignancies. Despite the identification of the epigenetical silencing of the NY-ESO1 gene in a large variety of tumors, the molecular mechanism involved in this phenomenon is not fully elucidated. In two non epithelial cancers (glioma and mesothelioma), we found that the epigenetic regulation of the NY-ESO1 gene requires the sequential recruitment of the HDAC1-mSin3a-NCOR, Dnmt3b-HDAC1-Egr1 and Dnmt1-PCNA-UHRF1-G9a complexes. Thus, our data illustrate the orchestration of a sequential epigenetic mechanism including the histone deacetylation and methylation, and the DNA methylation processes.     

CYP1A1, SULT1A1, and SULT1E1 polymorphisms are risk factors for endometrial cancer susceptibility

BACKGROUND: In estrogen biosynthetic pathways, many enzymes are important for metabolism, detoxification, and bioavailability. Polymorphisms in these genes may have an effect on the enzymes' function. For example, higher expression and activation of biosynthetic enzymes and lower expression and activation of conjugation enzymes may lead to high toxicity or carcinogenesis. The authors hypothesized that single nucleotide polymorphisms (single nucleotide polymorphisms) of CYP1A1, CYP1A2, CYP1B1, CYP17, SULT1A1, SULT1E1, and SHBG genes may be risk factors for endometrial cancer. METHODS: DNA samples from 150 cases of endometrial cancer and healthy controls (n = 165) were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to determine the genotypic frequency of 13 different polymorphic loci on the CYP1A1 (m1, m2, m3, m4), CYP1A2 1F, CYP1B1 codon432, COMT codon158, CYP17, SULT1A1 (Arg213His, 14A/G, 85C/T in the 3' flanking region), SULT1E1-64G/A promoter region, and SHBG genes. Genotyping was validated by direct DNA sequencing. The authors also investigated the relation between expression of CYP1A1 in endometrial cancer tissues and genotypes of CYP1A1 m1. RESULTS: A decreased frequency of TC + CC genotype of the CYP1A1 m1 (T/C) polymorphism was observed in endometrial cancer patients compared with controls (OR = 0.42; 95% CI, 0.27-0.69). The T-A haplotype of CYP1A1 m1 and m2 was increased in endometrial cancer patients (P = .017). The frequency of CYP1A1 m1 T/C + C/C was higher in a high CYP1A1 expression group (P = .009). The authors also found that individuals carrying the variants of SULT1A1 codon213 and 2 single nucleotide polymorphisms in the 3' flanking region (14A/G and 85C/T) had an increased risk for endometrial cancer. The frequencies of G-A-C and A-G-T haplotypes of these 3 variants were higher in endometrial cancer patients (P < .0001; P = .0002). In addition, the frequency of combined genotypes (SULT1A1 213 GA + AA and CYP1A1 m1 TT) was higher in endometrial cancer patients. (OR, 4.58; 95% CI, 2.35-8.93). CONCLUSIONS: This is the first report on the combined association of CYP1A1 and SULT gene polymorphisms in endometrial cancer that suggests a decreased single nucleotide polymorphism of CYP1A1 and an increased single nucleotide polymorphism for SULT1A1 and SULT1E1 genes may be risk factors for endometrial cancer in Caucasians.     

CYP1A1.

CYP1A1 plays an important role in the metabolism of polycyclic hydrocarbons that occur in the environment and several studies suggest that the genetic polymorphism of the gene may play a role in the predisposition to cancer. In order to evaluate the function of CYP1A1 in vivo as a host factor determinant of environmentally-caused cancers in humans, additional investigations are needed involving not only molecular epidemiological approaches in different ethnic populations but also more direct approaches such as the use of gene-targeted mice as a model system.     

DNA切除修复交叉互补基因1、乳腺癌易感基因、核苷酸还原酶1与非小细胞肺癌

 阐述了近年来非小细胞肺癌（NSCLC）化疗敏感性与DNA 切除修复交叉互补基因1 （ERCC1）、乳腺癌易感基因（BRCA1）、核苷酸还原酶1（RRM1）基因表达关系的研究进展，分析3个基因对NSCLC个体化化疗潜在的指导意义     

Methoxyestrogens exert feedback inhibition on cytochrome P450 1A1 and 1B1

Cytochrome P450 1A1 (CYP1A1) and 1B1 (CYP1B1) catalyze the oxidative metabolism of 17 beta-estradiol (E2) to catechol estrogens (2-OHE2 and 4-OHE2) and estrogen quinones, which may lead to DNA damage. Catechol-O-methyltransferase catalyzes the methylation of catechol estrogens to methoxyestrogens (2-MeOE2, 2-OH-3-MeOE2, and 4-MeOE2), which simultaneously lowers the potential for DNA damage and increases the concentration of 2-MeOE2, an antiproliferative metabolite. In this study, we showed that CYP1A1 and CYP1B1 recognized as substrates both the parent hormone E2 and the methoxyestrogens. Using purified recombinant enzymes, we demonstrated that CYP1A1 and CYP1B1 O-demethylated the methoxyestrogens to catechol estrogens according to Michaelis-Menten kinetics. Both CYP1A1 and CYP1B1 demethylated 2-MeOE2 and 2-OH-3-MeOE2 to 2-OHE2, whereas CYP1B1 additionally demethylated 4-MeOE2 to 4-OHE2. Because the P450-mediated oxidation of E2 and the O-demethylation of methoxyestrogens both yielded identical catechol estrogens as products, we used deuterated E2 (E2-d4), unlabeled methoxyestrogens, and gas chromatography/mass spectrometry to examine both reactions simultaneously. Kinetic analysis revealed that methoxyestrogens acted as noncompetitive inhibitors of E2 oxidation with K(i) ranging from 27 to 153 micro M. For both enzymes, the order of inhibition by methoxyestrogens was 2-OH-3-MeOE2 > or = 2-MeOE2 > 4-MeOE2. Thus, methoxyestrogens exert feedback inhibition on CYP1A1- and CYP1B1-mediated oxidative estrogen metabolism, thereby reducing the potential for estrogen-induced DNA damage.     

Polymorphisms in CYP1B1, GSTM1, GSTT1 and GSTP1, and susceptibility to breast cancer

Polymorphisms in the cytochrome P450 1B1 (CYP1B1) and glutathione S-transferase (GST) drug metabolic enzymes, which are responsible for metabolic activation/detoxification of estrogen and environmental carcinogens, were analyzed for their association with breast cancer risk in 541 cases and 635 controls from a North Carolina population. Each polymorphism, altering the catalytic function of their respective enzymes, was analyzed in Caucasian and African-American women. As reported in previous studies, individual polymorphisms did not significantly impact breast cancer risk in either Caucasian or African-American women. However, African-American women exhibited a trend towards a protective effect when they had at least one CYP1B1 119S allele (OR=0.53; 95% CI=0.20-1.40) and increased risk for those women harboring at least one CYP1B1 432V allele (OR=5.52; 95% CI=0.50-61.37). Stratified analyses demonstrated significant interactions in younger (age < or =60) Caucasian women with the CYP1B1 119SS genotype (OR=3.09; 95% CI=1.22-7.84) and younger African-American women with the GSTT1 null genotype (OR=4.07; 95% CI=1.12-14.80). A notable trend was also found in Caucasian women with a history of smoking and at least one valine allele at GSTP1 114 (OR=2.12; 95% CI=1.02-4.41). In Caucasian women, the combined GSTP1 105IV/VV and CYP1B1 119AA genotypes resulted in a near 2-fold increase in risk (OR=1.96; 95% CI=1.04-3.72) and the three way combination of GSTP1 105IV/VV, CYP1B1 119AS/SS and GSTT1 null genotypes resulted in an almost 4-fold increase in risk (OR=3.97; 95% CI=1.27-12.40). These results suggest the importance of estrogen/carcinogen metabolic enzymes in the etiology of breast cancer, especially in women before the age of 60, as well as preventative measures such as smoking cessation.