MicroRNAs in Myeloid Hematological Malignancies

MicroRNAs are 19-24 nucleotides noncoding RNAs which silence modulate the expression of target genes by binding to the messenger RNAs. Myeloid malignancies include a broad spectrum of acute and chronic disorders originating from from the clonal transformation of a hematopoietic stem cell. Specific genetic abnormalities may define myeloid malignancies, such as translocation t(9;22) that represent the hallmark of chronic myeloid leukemia. Although next-generation sequencing pro-vided new insights in the genetic characterization and pathogenesis of myeloid neoplasms, the molecular mechanisms underlying myeloid neoplasms are lacking in most cases. Recently, several studies have demonstrated that the expression levels of specific miRNAs may vary among patients with myeloid malignancies compared with healthy individuals and partially unveiled how miRNAs participate in the leukemic transformation process. Finally, in vitro experiments and pre-clinical model provided preliminary data of the safety and efficacy of miRNA inhibitory molecules, opening new avenue in the treatment of myeloid hematological malignancies.     

中国医学科学院北京协和医学院放射医学研究所天津市分子核医学重点实验室

血液肿瘤即造血系统的恶性肿瘤,是一种严重危害公共健康的疾病。目前,血液肿瘤诊断治疗的最理想方法就是分子特异性诊断和靶向治疗,但该方法面临的最大困难就是分子靶点的选择。噬菌体展示技术是近十年发展起来的一种新的生物学技术,具有高通量筛选、模拟天然表位、易于纯化、将蛋白功能与编码基因相统一等优点,广泛应用于功能性蛋白质和多肽的筛选、蛋白质间的识别与相互作用、抗原表位的鉴定、基因工程抗体的筛选等多个分子生物学领域,非常适于理想靶点的选择。目前,噬菌体文库技术在血液肿瘤诊治中的应用主要集中在噬菌体抗体文库和噬菌体随机肽库上。本文就噬菌体展示技术在血液肿瘤诊断治疗中的研究成果做一总结分析,并对该技术在这一领域的应用前景进行展望。     

单克隆抗体药物与血液系统恶性肿瘤的治疗

单克隆抗体凭借其特异性强、副作用较小的优点,越来越广泛地应用于疾病的诊断与治疗。单克隆抗体药物在血液系统恶性肿瘤的治疗中也发挥了重要作用。目前,经美国食品与药品管理局(FDA)批准用于治疗血液系统恶性肿瘤的单克隆抗体药物已有六种,在临床取得良好的治疗效果。单克隆抗体药物主要通过对肿瘤细胞的直接杀伤作用、抗体依赖性细胞介导的细胞毒性反应(ADCC)、补体依赖性细胞毒性反应(CDC)和改变信号通路等机制达到治疗肿瘤的效果。另外,将单克隆抗体与放射性核素、化疗药物和毒素等偶联,用于肿瘤等疾病的靶向治疗研究,成为生物治疗领域的热点。该文对近年来国际上用于血液系统恶性肿瘤治疗的单克隆抗体药物进行了概括和总结,讨论了治疗性单克隆抗体药物存在的问题和应用前景。     

p73基因在血液系统恶性肿瘤中的生物学行为

p73是肿瘤抑制基因p53家族新成员.它表达多种具有不同功能特点的蛋白质异构体.综述p73蛋白的分子结构、功能以及在血液系统恶性肿瘤中的生物学行为,旨在探索p73与血液系统恶性肿瘤的关系,为血液系统恶性肿瘤的诊断、治疗及预后提供理论依据.     

脑靶向寡核苷酸药物策略用于衰老相关脑部疾病治疗

寡核苷酸药物近10年发展迅速,已有多款应用于临床治疗。因其设计便捷、序列灵活、特异性高,有望解决许多靶点难成药的困境,并且其临床转化周期和成本较低,目前已成为新兴生物技术药物研发的前沿领域。脑部疾病包括多种目前无法治愈的疾病,如神经退行性疾病、胶质瘤、运动神经元疾病等,其中很多与年龄相关,被认为是衰老相关脑部疾病。因其病因复杂,许多靶点难成以药,同时由于脑部特殊屏障系统“血脑屏障”的存在,导致大部分药物无法实现脑部病灶的有效积累,众多小分子药物遭遇临床转化失败。寡核苷酸类药物的特异性和序列灵活性提供了新的成药可能性,但同样面临脑部递送的挑战。尽管目前已有多款寡核苷酸类药物应用于医疗市场,但脑靶向寡核苷酸药物仍然极为罕见,随着纳米递送和脑靶向基团研究的逐渐成熟,未来5~10年寡核苷酸药物用于脑部疾病治疗将成为可能。本文针对本领域重点话题如寡核苷酸药物临床批准的应用案例、脑靶向寡核苷酸药物的递送瓶颈和当前策略,以及衰老相关脑部疾病的寡核苷酸药物潜在靶点进行了梳理,同时对临床转化中的难点和面临的挑战展开了综述和讨论。     

ADAR1介导的RNA编辑在血液肿瘤中的调控作用

RNA编辑是发生于双链RNA（dsRNA）上的一类重要转录后反应,可通过碱基插入、缺失或替换的方式改变RNA的核苷酸序列从而丰富转录组和蛋白质组水平的多样性。哺乳动物中最常见的RNA编辑是ADAR家族介导的腺嘌呤-次黄嘌呤编辑（A-to-I）,其在碱基配对过程中被识别为鸟嘌呤。人类转录组中已报道了数百万个A-to-I编辑位点,而ADAR1是最主要的催化酶。在血液肿瘤中,ADAR1的失调将直接影响基因编码区、非编码区和miRNA前体的A-to-I编辑状态,从而导致一系列分子事件改变,如蛋白质编码序列改变、内含子滞留、选择性剪接和miRNA生物发生受抑制。近年来研究发现,异常的RNA编辑导致分子调控网络的紊乱,促进细胞增殖、凋亡受阻和细胞耐药,是白血病干细胞（LSCs）生成和干性维持的重要因素。目前,以RNA编辑为靶点的新药（如rebecsinib）已经在动物实验中取得良好疗效。有别于传统抗肿瘤药,表观遗传抗肿瘤药有望克服血液肿瘤的耐药、复发难题,为患者提供全新治疗选择。本综述总结了ADAR1介导的RNA编辑在血液肿瘤中的作用机制及其生物学功能研究的进展,并探讨了其在药物研发和临床应用中的价值。     

Prognostic Role of MicroRNA-181a/b in Hematological Malignancies: A Meta-Analysis

Background

Emerging evidence has shown that miRNAs participate in human carcinogenesis as tumor suppressors or oncogenes, and have prognostic value for patients with cancers. In recent years, the miR-181 family was found dysregulated in a variety of human cancers and significantly associated with clinical outcome of cancerous patients. MiR-181a and miR-181b (miR-181a/b) were the most investigated members in the family. However, the results of miR-181a/b from different studies were inconsistent. Therefore, we performed a meta-analysis to summarize all the results from available studies, aiming to delineate the prognostic role of miR-181a/b in human cancers.

Methods

The identified articles were retrieved from the two main on-line databases, PubMed and EMBASE. We extracted and estimated the hazard ratios (HRs) for overall survival (OS), which compared the high and low expression levels of miR-181a/b in patients of the available studies. Each individual HR was used to calculate the pooled HR.

Results

Eleven studies of 1252 patients were selected into the final meta-analysis after a strict filtering and qualifying process. Fixed model or random model method was chosen depending on the heterogeneity between the studies. The subgroup analysis showed that high expressed miR-181a/b could prolong OS in patients with hematological malignancies rather than low expression level (HR = 0.717, P<0.0001). But the expression of miR-181a/b was not significantly relative to OS in patients with various cancers (HR = 0.861, p = 0.356).

Conclusion

Our study indicates that the expression level of miR-181a/b is significantly associated with OS in hematological malignancies and can be an important clinical prognostic factor for those patients.     

Diverse Hematological Malignancies Including Hodgkin-Like Lymphomas Develop in Chimeric MHC Class II Transgenic Mice

A chimeric HLA-DR4-H2-E (DR4) homozygous transgenic mouse line spontaneously develops diverse hematological malignancies with high frequency (70%). The majority of malignancies were distributed equally between T and B cell neoplasms and included lymphoblastic T cell lymphoma (LTCL), lymphoblastic B cell lymphoma (LBCL), diffuse large B cell lymphoma (DLBCL), the histiocyte/T cell rich variant of DLBCL (DLBCL-HA/T cell rich DLBCL), splenic marginal zone lymphoma (SMZL), follicular B cell lymphoma (FBL) and plasmacytoma (PCT). Most of these neoplasms were highly similar to human diseases. Also, some non-lymphoid malignancies such as acute myeloid leukemia (AML) and histiocytic sarcoma were found. Interestingly, composite lymphomas, including Hodgkin-like lymphomas, were also detected that had CD30⁺ Hodgkin/Reed-Sternberg (H/RS)-like cells, representing a tumor type not previously described in mice. Analysis of microdissected H/RS-like cells revealed their origin as germinal center B cells bearing somatic hypermutations and, in some instances, crippled mutations, as described for human Hodgkin lymphoma (HL). Transgene integration in an oncogene was excluded as an exclusive driving force of tumorigenesis and age-related lymphoma development suggests a multi-step process. Thus, this DR4 line is a useful model to investigate common molecular mechanisms that may contribute to important neoplastic diseases in man.     

血液恶性肿瘤患者化疗治疗预防侵袭性真菌感染的临床分析与研究

目的:侵袭性真菌感染在血液恶性肿瘤化疗患者中时常出现,其感染周期较长,且易产生抗药性,给患者带来极大痛苦,为了探讨血液恶性肿瘤患者侵袭性真菌感染的最佳临床预防方案,我院进行了相关研究.方法:选取2009年3月-2012年1月入住我院并接受治疗的血液恶性肿瘤患者156例,将所有患者随机分为观察组和对照组,每组患者78例,其中对照组传统预防方案,观察组采用伊曲康唑预防方案.两组患者化疗治疗后对两组患者的侵袭性真菌感染状况及药物不良反应,不良反应包括血压升高、转氨酶升高、肾功能衰竭、腹泻、皮疹、气胸、药物过敏等.同时对两组患者进行满意度调查.结果:观察组感染率低于对照组27个百分点(P＜0.05),不良反应低于对照组5.1个百分点(P＜0.05),观察组的满意度高于对照组6.4个百分点(P＜0.05),均具有显著性差异,具有统计学意义.结论:观察组由于在传统预防方案的基础上额外采用了伊曲康唑预防对患者进行预防,使得观察组的化疗感染率、不良反应状况均低于对照组,而满意度明显高于对照组,因此对血液恶性肿瘤患者化疗时应用伊曲康唑预防方案可以起到明显的侵袭性真菌感染预防效果,该方案值得进一步推广.     

Derivation and Validation of a Scoring System to Identify Patients with Bacteremia and Hematological Malignancies at Higher Risk for Mortality

Background

The aim of this study was to develop and validate a reliable clinical prediction rule that could be employed to identify patients at higher likelihood of mortality among those with hematological malignancies (HMs) and bacterial bloodstream infections (BBSIs).

Methods and Findings

We conducted a retrospective cohort study in nine Italian hematological units. The derivation cohort consisted of adult patients with BBSI and HMs admitted to the Catholic University Hospital (Rome) between January 2002 and December 2008. Survivors and nonsurvivors were compared to identify predictors of 30-day mortality. The validation cohort consisted of patients hospitalized with BBSI and HMs who were admitted in 8 other Italian hematological units between January 2009 and December 2010. The inclusion and exclusion criteria were identical for both cohorts, with type and stage of HMs used as matching criteria. In the derivation set (247 episodes), the multivariate analysis yielded the following significant mortality-related risk factors acute renal failure (Odds Ratio [OR] 6.44, Confidential Interval [CI], 2.36–17.57, P<0.001); severe neutropenia (absolute neutrophil count <100/mm³) (OR 4.38, CI, 2.04–9.43, P<0.001); nosocomial infection (OR, 3.73, CI, 1.36–10.22, P = 0.01); age ≥65 years (OR, 3.42, CI, 1.49–7.80, P = 0.003); and Charlson Comorbidity Index ≥4 (OR, 3.01, CI 1.36–6.65, P = 0.006). The variables unable to be evaluated at that time (for example, prolonged neutropenia) were not included in the final logistic model. The equal-weight risk score model, which assigned 1 point to each risk factor, yielded good-excellent discrimination in both cohorts, with areas under the receiver operating curve of 0.83 versus 0.93 (derivation versus validation) and good calibration (Hosmer-Lemshow P = 0.16 versus 0.75).

Conclusions

The risk index accurately identifies patients with HMs and BBSIs at high risk for mortality; a better initial predictive approach may yield better therapeutic decisions for these patients, with an eventual reduction in mortality.     

Nosocomial Infection in Adult Admissions with Hematological Malignancies Originating from Different Lineages: A Prospective Observational Study

Background

Nosocomial infection (NI) causes prolonged hospital stays, increased healthcare costs, and higher mortality among patients with hematological malignancies (HM). However, few studies have compared the incidence of NI according to the HM lineage.

Objective

To compare the incidence of NI according to the type of HM lineage, and identify the risk factors for NI.

Methods

This prospective observational study monitored adult patients with HM admitted for >48 hours to the General Hospital of the People''s Liberation Army during 2010–2013. Attack rates and incidences of NI were compared, and multivariable logistic regression was used to control for confounding effects.

Results

This study included 6,613 admissions from 1,922 patients. During these admissions, 1,023 acquired 1,136 NI episodes, with an attack rate of 15.47% and incidence of 9.6‰ (95% CI: 9.1–10.2). Higher rates and densities of NIs were observed among myeloid neoplasm (MN) admissions, compared to lymphoid neoplasm (LN) admissions (28.42% vs. 11.00%, P<0.001 and 11.4% vs. 8.4‰, P<0.001). NI attack rates in acute myeloid leukemia (AML) and myelodysplastic/myeloproliferative neoplasm (MDS/MPN) were higher than those in MDS (30.69% vs. 20.19%, P<0.001; 38.89% vs. 20.19%, P = 0.003). Attack rates in T/NK-cell neoplasm and B-cell neoplasm were higher than those in Hodgkin lymphoma (15.04% vs. 3.65%; 10.94% vs. 3.65%, P<0.001). Multivariable regression analysis indicated prolonged hospitalization, presence of central venous catheterization, neutropenia, current stem cell transplant, infection on admission, and old age were independently associated with higher NI incidence. After adjusting for these factors, MN admissions still had a higher risk of infection (odds ratio 1.34, 95% CI: 1.13–1.59, P<0.001).

Conclusion

Different NI attack rates were observed for HM from different lineages, with MN lineages having a higher attack rate and incidence than LN lineages. Special attention should be paid to MN admissions, especially AML and MDS/MPN admissions, to control NI incidence.     

Acute Kidney Injury in Patients with Newly Diagnosed High-Grade Hematological Malignancies: Impact on Remission and Survival

Background

Optimal chemotherapy with minimal toxicity is the main determinant of complete remission in patients with newly diagnosed hematological malignancies. Acute organ dysfunctions may impair the patient’s ability to receive optimal chemotherapy.

Design and Methods

To compare 6-month complete remission rates in patients with and without acute kidney injury (AKI), we collected prospective data on 200 patients with newly diagnosed high-grade malignancies (non-Hodgkin lymphoma, 53.5%; acute myeloid leukemia, 29%; acute lymphoblastic leukemia, 11.5%; and Hodgkin disease, 6%).

Results

According to RIFLE criteria, 137 (68.5%) patients had AKI. Five causes of AKI accounted for 91.4% of cases: hypoperfusion, tumor lysis syndrome, tubular necrosis, nephrotoxic agents, and hemophagocytic lymphohistiocytosis. Half of the AKI patients received renal replacement therapy and 14.6% received suboptimal chemotherapy. AKI was associated with a lower 6-month complete remission rate (39.4% vs. 68.3%, P<0.01) and a higher mortality rate (47.4% vs. 30.2%, P<0.01) than patients without AKI. By multivariate analysis, independent determinants of 6-month complete remission were older age, poor performance status, number of organ dysfunctions, and AKI.

Conclusion

AKI is common in patients with newly diagnosed high-grade malignancies and is associated with lower complete remission rates and higher mortality.     

Carbohydrate Modifications in Antisense Oligonucleotide Therapy: New Kids on the Block

Abstract

Chemical modifications to improve the efficacy of an antisense oligonucleotide are designed to increase the binding affinity to target RNA, to enhance the nuclease resistance, and to improve cellular delivery. Among the different sites available for chemical modification in a nucleoside building block, the 2′-position of the carbohydrate moiety¹ has proven to be the most valuable for various reasons: (1) 2′-modification can confer an RNA-like 3′-endo conformation to the antisense oligonucleotide. Such a preorganization for an RNA like conformation^2,3,4,5 greatly improves the binding affinity to the target RNA; (2) 2′-modification provides nuclease resistance to oligonucleotides; (3) 2′-modification provides chemical stability against potential depurination conditions pharmacology evaluations and correlation with pharmacokinetic changes are emerging from these novel chemical modifications. Analytical chemistry of modified oligonucleotides before and after biological administration of antisense oligonucleotides with techniques such as capillary gel electrophoresis (CGE) and mass spectrometry help to determine the purity as well as the in vivo fate of these complex molecules. Large-scale synthesis is becoming a tangible reality for antisense oligonucleotides. Nucleic acid chemists and biologists alike are beginning to understand the structure-biological activity in terms of basic physical-organic parameters such as the gauche effect, the charge effect and conformational constraints. Synthesis of chimeric designer oligonucleotides bringing the attractive features of different modifications to a given antisense oligonucleotide sequence to generate synergistic interactions is forthcoming³⁰. These advances along with the potential availability of complete human genome sequence information promise a bright future for the widespread use of nucleic acid based therapeutics.     

Identification of Novel HLA-A*24:02-Restricted Epitope Derived from a Homeobox Protein Expressed in Hematological Malignancies

The homeobox protein, PEPP2 (RHOXF2), has been suggested as a cancer/testis (CT) antigen based on its expression pattern. However, the peptide epitope of PEPP2 that is recognized by cytotoxic T cells (CTLs) is unknown. In this study, we revealed that PEPP2 gene was highly expressed in myeloid leukemia cells and some other hematological malignancies. This gene was also expressed in leukemic stem-like cells. We next identified the first reported epitope peptide (PEPP2^271-279). The CTLs induced by PEPP2^271-279 recognized PEPP2-positive target cells in an HLA-A*24:02-restricted manner. We also found that a demethylating agent, 5-aza-2’-deoxycytidine, could enhance PEPP2 expression in leukemia cells but not in blood mononuclear cells from healthy donors. The cytotoxic activity of anti-PEPP2 CTL against leukemic cells treated with 5-aza-2’-deoxycytidine was higher than that directed against untreated cells. These results suggest a clinical rationale that combined treatment with this novel antigen-specific immunotherapy together with demethylating agents might be effective in therapy-resistant myeloid leukemia patients.     

Management of Hyperglycemia in Diabetic Patients with Hematologic Malignancies During Dexamethasone Therapy

ObjectiveTo compare the response to different insulin regimens for management of hyperglycemia in diabetic patients with hematologic malignancies who are receiving dexamethasone.MethodsA retrospective analysis was conducted to determine whether a basal bolus insulin (BBI) regimen with detemir and aspart is superior to a sliding scale regular insulin (SSI) regimen for management of hyperglycemia in hospitalized diabetic patients receiving dexamethasone.ResultsForty patients with hematologic malignancies were treated with intravenous (8 to 12 mg/day) or oral (40 mg/day) dexamethasone for 3 days. The average blood glucose (BG) level was 301 ± 57 mg/dL in the SSI group (n = 28) and 219 ± 51 mg/dL in the BBI group (n = 12) (P <.001). The BBI regimen resulted in an average BG reduction of 52 ± 82 mg/dL throughout the course of dexa-methasone therapy, while the SSI regimen produced an increase in the mean daily BG level of 128 ± 77 mg/dL (P <.001). On the last day of dexamethasone administration, the insulin requirement was 49 ± 29 units/day in the SSI group and 122 ± 39 units/day in the BBI group (P <.001). Three patients in the SSI group developed diabetic ketoacidosis or hyperosmolar hyperglycemia during steroid therapy. No hypoglycemia was observed in either group. The length of stay and infection rates were similar between groups.ConclusionBasal and bolus insulin regimen is an effective and safe approach for managing dexamethasone-induced hyperglycemia in hospitalized patients with hematologic malignancies. (Endocr Pract. 2013;19:231-235)     

光动力治疗在各类恶性肿瘤病人姑息治疗中的应用探讨

光动力治疗(photodynamic therapy,PDT)是近二十年来新兴的肿瘤治疗方法,与肿瘤传统手术、化疗和放疗方法相比,能选择性地消灭局部的原发和复发肿瘤,而不伤及正常组织。大多数肿瘤出现临床症状时,已是肿瘤晚期,丧失了肿瘤治疗的最佳时机。光动力治疗作为新兴的肿瘤治疗技术,能够以较小创伤为代价改善患者的生活质量,并提高患者生存时间,有望成为恶性肿瘤姑息性治疗的首选。     

Prevalence and Positive Correlates of Posttraumatic Stress Disorder Symptoms among Chinese Patients with Hematological Malignancies: A Cross-Sectional Study

Purpose

Positive psychological constructs have been given increasing attention in research on the coping resources of cancer-related distresses. However, little research is available on posttraumatic stress disorder (PTSD) in patients with hematological malignancies. The purposes of this study were to assess the prevalence of PTSD symptoms and to explore the associations of perceived social support (PSS), hope, optimism and resilience with PTSD symptoms among Chinese patients with hematological malignancies.

Methods

A cross-sectional study was conducted during the period from July 2013 through April 2014. A total of 225 inpatients with hematological malignancies, which were eligible for the study, completed the Post-traumatic Stress Checklist-Civilian Version, Multidimensional Scale of Perceived Social Support, Adult Hope Scale, Life Orientation Scale-Revised, and Resilience Scale. Hierarchical regression analysis was performed to explore the correlates of PTSD symptoms.

Results

Overall, the prevalence of PTSD symptoms was 10.7%. Initially, PSS was negatively associated with PTSD symptoms (β = -0.248, P < 0.01). However, when positive psychological variables were added, optimism was negatively associated with PTSD symptoms (β = -0.452, P < 0.01), and gender had a significant effect on PTSD symptoms. Women were more vulnerable to these symptoms than men (β = 0.123, P < 0.05). When the analysis was performed separately by gender, only optimism showed a significantly negative association with PTSD symptoms in both men (β = -0.389, P < 0.01) and women (β = -0.493, P < 0.01).

Conclusions

Some patients with hematological malignancies suffer from PTSD symptoms. The positive effects of PSS and optimism on PTSD symptoms suggest that an integrated approach to psychosocial intervention from both external and internal perspectives could have practical significance. Gender difference should be considered in developing potential interventions in reducing cancer-related PTSD symptoms.