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。      

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-1/PD-L1抑制剂在晚期尿路上皮癌中的研究进展

摘 要：含顺铂方案的化疗是晚期尿路上皮癌的一线治疗方式,不耐受顺铂化疗的及一线标准化疗后发生疾病进展的患者可选择的有效治疗有限,平均生存期约5~10个月。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）抑制剂在大型临床试验中显示出持久的抗肿瘤效应和可耐受的安全性,为改善晚期尿路上皮癌患者预后带来了希望。PD-1抑制剂Pembrolizumab是第一个获得美国食品药品管理局（Food and Drug Administration,FDA）批准的治疗晚期尿路上皮癌的一线免疫治疗药物。2种PD-1抑制剂Pembrolizumab和Nivolumab,3种PD-L1抑制剂Atezolizumab、Durvalumab和Avelumab,先后获得美国FDA批准作为含铂方案化疗进展的晚期尿路上皮癌患者的二线治疗药物。全文就PD-1/PD-L1抑制剂在晚期尿路上皮癌中的研究进展作一综述。     

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。     

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。     

循环外泌体PD-L1表达水平与PD-1/PD-L1抑制剂治疗恶性肿瘤疗效的相关性研究现状

外泌体作为具有生物学功能的小囊泡,是近年肿瘤研究领域关注的热点。研究发现,肿瘤细胞分泌的外泌体表达的程序性死亡受体配体1(programmed death ligand 1,PD-L1),可在肿瘤患者外周血液中检测到,可能参与并抑制机体免疫反应。近年来,一些研究发现,外泌体PD-L1可能影响程序性死亡受体1（programmed death 1,PD-1）/PD-L1抑制剂的抑制效应。反之,亦然。应用PD-1/PD-L1抑制剂治疗,可影响外泌体PD-L1的表达水平。二者有怎样的联系和相关性？本文就循环外泌体PD-L1在不同肿瘤免疫反应及抗PD-1/PD-L1免疫治疗中的研究进展作一综述。     

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-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在肿瘤免疫逃逸中的作用机制及其临床应用

程序性死亡受体-1 (programmed death receptor-1,PD-1)是T细胞上主要存在的一种抑制性受体,与程序性死亡受体配体-1 (programmed death receptor ligand-1,PD-L1)相互作用,可抑制T细胞增殖、活化.在正常机体中,PD-1/PD-L1信号通路对维持机体的免疫耐受具有重要作用;而在肿瘤发生时,PD-1/PD-L1信号通路能抑制T细胞的免疫反应而促进肿瘤免疫逃逸的发生.本文从PD-1/PD-L1的发现及其结构、信号通路的作用机制、PD-1/PD-L1抗体在肿瘤免疫治疗中的应用等方面进行综述.     

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.     

CYP1A1 and GSTM1 polymorphisms affect urinary 1-hydroxypyrene levels after PAH exposure

Certain human biotransformation enzymes have been implicated in the formation and scavenging of the ultimate reactive metabolites, the diolepoxides, from polycyclic aromatic hydrocarbons (PAHs). In the present study, performed on aluminum smelter workers, we have analyzed airborne PAH, the pyrene metabolite 1-hydroxypyrene (1-OHP) in urine, and genotypes for biotransformation enzymes involved in PAH metabolism. The aim was to evaluate the correlation between external exposure and biomarkers of exposure and to investigate to what extent genetic polymorphism in metabolic enzymes can explain interindividual variation in urinary 1-OHP levels. DNA was prepared from blood samples from 98 potroom workers and 55 controls and altogether eight polymorphisms in the CYP1A1, mEH, GSTM1, GSTP1 and GSTT1 genes were analyzed. The 1-OHP excretion was found to correlate significantly (P 100-fold) and univariate and multivariate regression analyses were used to find the variables that could determine differences in excretion. The variation could, to some degree, be explained by differences in exposure to airborne particulate-associated PAHs, the use of personal respiratory protection devices, smoking habits and genetic polymorphisms in the cytochrome P450 1A1, GSTM1 and GSTT1 enzymes. The part of the variance that could be explained by differences in biotransformation genotypes seemed to be of the same order of magnitude as the variance explained by differences in exposure. In the control group as well as in the occupationally exposed group, the highest 1-OHP levels were observed in individuals carrying the CYP1A1 Ile/Val genotype who were also of the GSTM1 null genotype. The results show that urinary 1-OHP is a sensitive indicator of recent human exposure to PAHs and that it may also to some extent reflect the interindividual variation in susceptibility to PAHs.