All-trans retinoic acid in the treatment of pediatric acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a rare form of acute myeloid leukemia with specific epidemiological, pathogenetic and clinical features. Its frequency varies widely among nations, with a decreased incidence among ‘Nordic’ origin populations. The molecular hallmark of the disease is the presence of a balanced reciprocal translocation resulting in the PML/RAR-α gene fusion, which represents the target of the all-trans retinoic acid (ATRA) therapy. The introduction of ATRA in conjunction with anthracyclines marked a turning point in the treatment of APL, previously associated with a significant morbidity and mortality. Nowadays the standard front-line therapy for pediatric APL includes ATRA in every phase of the treatment, resulting in a complete remission rate of 90–95%. Here we provide an overview of the role of ATRA in the treatment of pediatric APL, summarizing the most relevant clinical results of recent decades and investigating future therapeutic perspectives for children with APL.     

Significance of plasma transforming growth factor-β levels in radiotherapy for non–small-cell lung cancer

PURPOSE: In dose-escalation studies of radiotherapy (RT) for non-small-cell lung cancer (NSCLC), radiation pneumonitis (RP) is the most important dose-limiting complication. Transforming growth factor-beta1 (TGF-beta1) has been reported to be associated with the incidence of RP. It has been proposed that serial measurements of plasma TGF-beta1 can be valuable to estimate the risk of RP and to decide whether additional dose-escalation can be safely applied. The aim of this study was to evaluate prospectively the time course of TGF-beta1 levels in patients irradiated for NSCLC in relation to the development of RP and dose-volume parameters. METHODS AND MATERIALS: Plasma samples were obtained in 68 patients irradiated for medically inoperable or locally advanced NSCLC (dose range, 60.8-94.5 Gy) before and 4, 6, and 18 weeks after the start of RT. Plasma TGF-beta1 levels were determined using a bioassay on the basis of TGF-beta1-induced plasminogen activator inhibitor-1 expression in mink lung cells. All patients underwent chest computed tomography scans before RT that were repeated at 18 weeks after RT. The computed tomography data were used to calculate the mean lung dose (MLD) and to score the radiation-induced radiologic changes. RP was defined on the basis of the presence of either radiographic changes or clinical symptoms. Symptomatic RP was scored according to the Common Toxicity Criteria (Grade 1 or worse) and the Southwestern Oncology Group criteria (Grade 2 or worse). Multivariate analyses were performed to investigate which factors (pre- or posttreatment TGF-beta1 level, MLD) were associated with the incidence of RP. To improve our understanding of the time course of TGF-beta1 levels, we performed a multivariate analysis to investigate which factors (pre-RT TGF-beta1 level, MLD, RP) were independently associated with the posttreatment TGF-beta1 levels. RESULTS: The pre-RT TGF-beta1 levels were increased in patients with NSCLC (median 21 ng/mL, range, 5-103 ng/mL) compared with healthy individuals (range, 4-12 ng/mL). On average, the TGF-beta1 levels normalized toward the end of treatment and remained stable until 18 weeks after RT. In 29 patients, however, TGF-beta1 was increased at the end of RT with respect to the pre-RT value. The multivariate analyses revealed that the MLD was the only variable that correlated significantly with the risk of both radiographic RP (p = 0.05) and symptomatic RP, independent of the scoring system used (p = 0.05 and 0.03 for Southwestern Oncology Group and Common Toxicity Criteria systems, respectively). The TGF-beta1 level at the end of RT was significantly associated with the MLD (p <0.001) and pre-RT TGF-beta1 level (p = 0.001). CONCLUSION: The MLD correlated significantly with the incidence of both radiographic and symptomatic RP. The results of our study did not confirm the reports that increased levels of TGF-beta1 at the end of RT are an independent additional risk factor for developing symptomatic RP. However, the TGF-beta1 level at the end of a RT was significantly associated with the MLD and the pre-RT level.     

急性早幼粒细胞白血病处理中的共识和争议

急性早幼粒细胞白血病的正确处理包括如下方面使用全反式维甲酸和蒽环类为基础的化疗联合治疗,恰当的支持治疗,从细胞和分子遗传水平证实诊断,正确分析治疗反应及通过分子监测评估疾病复发的危险性。本文综述初治APL患者现代处理方法,并提出一些尚有争议的问题供探讨。     

Altered expression of transforming growth factor-β1 mrna and protein in mouse skin carcinogenesis

Transforming growth factor (TGF)-β1, whose gene is located on mouse chromosome 7, has been proposed to be involved in skin carcinogenesis. In the study presented here, we demonstrated that single topical treatments with different types of tumor promoters, i.e., the protein kinase C activator 12-O-tetradecanoylphorbol-13-acetate (TPA, 2 μg); the non–protein kinase C activators anthralin (22.6 μg), benzoyl peroxide (20 mg), and cumene hydroperoxide (1.2 mg); the first-stage tumor promoters 4-O-methyl-TPA (500 μg) and A23187 (166 μg); and the second-stage tumor promoter mezerein (2 μg) produced transient induction of TGF-β1 mRNA in SSIN (inbred SENCAR) mouse skin. The time of maximum induction varied from 3 to 12 h; the relative extent of induction was ranked as cumene hydroperoxide > benzoyl peroxide > anthralin > TPA > 4-O-methyl-TPA > mezerein > A23187. These findings suggested that TGF-β1 mRNA induction is a common response of skin to several types of complete and stage-specific promoters; however, the extent of induction did not correlate with the reported hyperplastic activity of single applications of these promoters. We also demonstrated that TGF-β1 mRNA expression in papillomas of SENCAR mice generally correlated with expression levels of cyclin D1, another gene on chromosome 7, and with stage of tumor progression. TGF-β1 mRNA expression was constitutively elevated in most squamous cell carcinomas from either initiation-promotion or complete carcinogenesis protocols. Cell lines established from carcinomas also overexpressed TGF-β1 mRNA. Immunohistochemical staining of tissue sections of normal and TPA-treated skin revealed the presence of extracellular TGF-β1 protein in the dermis and intracellular TGF-β1 protein in the epidermis, especially in the suprabasal layers. The staining patterns of papillomas varied, with 62 ± 13% of the tissue showing strong intracellular staining but only 25 ± 8% of the connective tissue staining for extracellular TGF-β1. Variable staining patterns were also found in carcinomas; some areas stained heavily for both the intracellular and extracellular forms of TGF-β1. Overall, 28 ± 6% of the tissue of the 12 analyzed carcinomas stained for the intracellular form and 18 ± 5% for the extracellular from of TGF-β1. © 1994 Wiley-Liss, Inc.     

急性早幼粒细胞白血病细胞黏附分子表达与维甲酸综合征的关系

目的 :观察急性早幼粒细胞白血病细胞在诱导分化中黏附分子的表达与维甲酸综合征的关系。方法 :流式细胞仪方法进行细胞表面标记检测 ,标本来自于 16例急性早幼粒细胞白血病患者的骨髓标本 ,标本采集时间为应用全反式维甲酸治疗前、用药后 7d、14d及 2 8d。结果 :16例患者在诱导缓解过程中有 3例患者出现维甲酸综合征 ,与CD11b表达时间的相关性为 7d :r =0 884,P =0 0 0 0 ;14d :r =0 5 41,P =0 0 3 0 ;2 8d :r =0 3 8,P =0 2 3 0。结论 :急性早幼粒白血病细胞在全反式维甲酸诱导缓解过程中早期、同步表达细胞黏附分子CD11b与维甲酸综合征的发生密切相关。     

漆姑草醇提物对人急性早幼粒白血病细胞的诱导分化作用

目的： 探讨漆姑草醇提物（HSJ）对人急性早幼粒白血病细胞（NB4）的诱导分化作用。方法： 以NB4细胞为研究对象,设HSJ低（30 μg/mL）、中（60 μg/mL）、高（120 μg/mL）剂量组和阴性对照组,共4组;HSJ作用NB4细胞48 h后,采用透射电镜法观察NB4细胞形态;硝基四唑氮（NBT）还原实验检测NB4细胞分化能力;流式细胞术检测NB4细胞周期分布;流式细胞术检测NB4细胞表面分化抗原CD14和CD11b细胞的表达率;实时荧光定量PCR （qPCR）检测c-fos mRNA表达;Western blot检测c-fos蛋白表达。结果： 与对照组比较,3个不同剂量HSJ处理组NB4细胞胞核均缩小,胞浆呈空泡状,核形呈肾形或蚕豆形;各HSJ处理组NB4细胞的NBT还原率均高于对照组,差异有统计学意义（P < 0.05）;HSJ处理组NB4细胞中G2期细胞比例均高于对照组,而S期细胞比例均低于对照组,差异有统计学意义（P < 0.05）;HSJ处理组CD14和CD11b阳性细胞表达率均高于对照组（P < 0.05）;HSJ低剂量组cfos mRNA和蛋白表达与对照组比较,差异均无统计学意义（P > 0.05）,HSJ中、高剂量组c-fos mRNA和蛋白表达均高于对照组,差异均有统计学意义（P < 0.05）。结论： HSJ可能诱导NB4细胞向成熟粒细胞方向分化。     

Induction of murine leukemia and lymphoma by dominant negative retinoic acid receptor alpha

Acute promyelocytic leukemia (APL) is invariably associated with chromosomal translocation to retinoic acid receptor alpha (RARalpha) locus. In a vast majority of cases, RARalpha translocates to and fuses with the promyelocytic leukemia (PML) gene. It was thought that the fusion protein PML-RARalpha acts as a double dominant negative mutant to inhibit the PML and RARalpha signaling. In an attempt to study the physiological role of retinoic acid in mammary gland development, we created a transgenic model system expressing a dominant negative RARalpha under the regulation of murine mammary tumor viral promoter. We found that the transgene was also targeted to the lymphoid system in addition to mammary gland. Here we showed that dominant negative RARalpha induced acute lymphoblastic leukemia and lymphoma development in the transgenic mice. Retinoic acid blocked tumor development ex vivo through induction of apoptosis. Thus, our results suggested that disruption of RARalpha signaling was the first essential step in the development of APL in vivo.     

全反式维甲酸联合亚砷酸治疗儿童急性早幼粒细胞白血病疗效分析

目的:评价全反式维甲酸（all-trans retinoic acid,ATRA）联合亚砷酸(ATO)治疗儿童急性早幼粒细胞性白血病(acute promyelocytic leukemia,APL) 的疗效。方法:2009年8月至2013年4月于我院儿科就诊的APL患儿18例,将亚砷酸注射液（0.1% ATO）按6mg/m2稀释于50g/L的葡萄糖溶液200-400ml中,静脉滴注持续3-5h,1次/d,ATRA 20-35mg/(m·d),口服,3次/d。结果:18例患儿获得完全缓解（CR）率为94.4%;12例初治患儿均获得CR,6例复发患儿中5例获得CR。获得缓解时间（26.2±1.2）天,无明显不良反应发生。结论:ATRA联合亚砷酸治疗儿童APL疗效显著,有效缩短达到CR的时间,毒副作用基本可以耐受,本方案可以有效缩短治疗时间,降低患儿家庭经济负担,对患儿长期治疗具有重要作用,是一种经济有效的治疗方案。     

Platelet PDGF and TGF-β Levels in Myeloproliferative Disorders

Myeloproliferative disorders mainly including essential thrombocythemia, polycythemia vera, chronic myeloid leukemia and myelofibrosis with myeloid metaplasia are clonal myeloproliferative diseases in which myelofibrosis is commonly observed. The pathogenesis of myelofibrosis still remains unclear. However it was proposed that an inappropriate release of PDGF from either megakaryocytes in bone marrow or platelets in circulation might promote medullary fibrosis. Recently the role of another peptide growth factor, namely TGF-β, in the fibrotic process was emphasized. This review will focus on the different studies aimed at the evaluation of intraplatelet PDGF and TGF-β content in patients with the various MPD, and outline the salient results lending support to the potential role of PDGF and TGF-β in the promotion of myelofibrosis.     

Transforming growth factor-β1 expression in Syrian hamster cheek pouch carcinogenesis

The expression pattern of transforming growth factor-β1 (TGF-β1) during the stages of complete carcinogenesis in the hamster cheek pouch model was studied. The right cheek pouches of 18 male hamsters were treated with 0.5% 7,12-dimethylbenz[a]anthracene (DMBA) for 16 wk. TGF-β1 was detected immunohistochemically in the resulting samples with two different polyclonal monospecific antibodies that recognize intracellular and extracellular forms of TGF-β1. In the normal cheek pouch, extracellular protein stained the corium strongly, but the reaction was not evenly distributed. As treatment progressed, the reaction increased in both area and intensity; the peak was reached at 8 wk. Intracellular TGF-β1 expression followed a similar pattern, with a peak at 4 wk of treatment. The results of northern blot analysis were concordant with the immunohistochemical results. Overexpression of TGF-β1 was also observed in the malignant tumors, but only the extracellular form of the protein was present; intracellular TGF-β1 was not detected in these tumors. The expression of TGF-β1 in this carcinogenesis model seems to have two formal stages, the first being an overexpression step as a reaction to the uncontrolled growth and the second being one in which tumors have no internal expression of TGF-β1 but in which external protein accumulates in the surrounding stroma. A possible explanation of this paradox may be that TGF-β1 has functions other than its growth-repressing activity. © 1994 Wiley-Liss, Inc.     

亚砷酸联合全反式维甲酸治疗急性早幼粒细胞白血病16例疗效观察

目的:观察亚砷酸(As2O3)与全反式维甲酸(ATRA)联合治疗初发急性早幼粒细胞白血病(APL)的疗效和不良反应.方法:As2O3联合ATRA治疗初治APL患者16例,As2O30.1%注射液10ml加入5%葡萄糖溶液500ml静脉点滴,持续4h,1次/d;ATRA40-60mg/d,分2次口服,观察完全缓解(CR)率,获得CR所需时间、不良反应.结果:15例患者获得CR,CR率93.8%,获得缓解时间(27.3±3.6)d,没有发现明显的不良反应.结论:As2O3,联合ATRA治疗初发APL患者疗效好,能缩短CR的时间,长期CR时间需要进一步观察.     

Liver regeneration and hepatocarcinogenesis in transforming growth factor-α-targeted mice

Transforming growth factor-α (TGFα), a member of the epidermal growth factor receptor ligand family, has been implicated in the regeneration and transformation of liver. Our recent development of mice that are homozygous for a disrupted TGFα gene allowed us to assess the requirement for this growth factor in these complex processes. We report here that although a 70% hepatectomy produced a significant increase in hepatic TGFα protein levels in wild-type mice, liver regeneration nevertheless proceeded normally in the absence of the growth factor. The hepatocyte labeling indices determined for homozygous targeted and wild-type mice at 36 and 48 h after hepatectomy were comparable, and the total liver DNA to body weight ratios 8 d after hepatectomy were essentially identical for the two genotypes. These results indicate that TGFα is not necessary for liver regeneration. To test its requirement in liver carcinogenesis, young mice were administered single doses of diethylnitrosamine (DEN) with or without subsequent chronic treatment with the promoting agent phenobarbital (PB). Both wild-type and homozygous mutant male mice treated with DEN or DEN plus PB developed multiple preneoplastic foci or tumors by 9 mo of age with relatively high incidence. However, while five of 88 tumors in wild-type mice attained a diameter greater than 5 mm and were classified as hepatocellular carcinomas, none of 132 tumors in livers of targeted mice reached this size. Furthermore, three of these large wild-type tumors expressed significantly elevated levels of TGFα protein compared with normal liver. These results indicate that TGFα is not required for early events in chemically induced hepatocarcinogenesis but suggest that it could be important in the progression from small preneoplastic foci to large tumors. © 1996 Wiley-Liss, Inc.     

Src family kinase inhibitor PP2 enhances differentiation of acute promyelocytic leukemia cell line induced by combination of all-trans-retinoic acid and arsenic trioxide

An all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) combination yields high-quality remission and survival in newly-diagnosed acute promyelocytic leukemia (APL). For subsequent similar data, NCCN guidelines indicate that ATRA plus ATO is one of the recommended regimens for the treatment of patients with APL. We demonstrated SFK (Src family kinase) inhibitor PP2-enhanced APL cell differentiation when combined with either ATRA or ATO with difference in activation of RA-induced genes. In this study, we investigated whether SFK inhibitor PP2 could enhance the differentiation of NB4 APL cells when combined with ATRA and ATO and the changes in the expression of intercellular adhesion molecule-1 (ICAM-1) derived from the retinoic acid receptor (RAR) target gene.     

Enhancement of sensitivity by bestatin of acute promyelocytic leukemia NB4 cells to all-trans retinoic acid

All-trans retinoic acid (ATRA) induces the differentiation of acute promyelocytic leukemia (APL) cells into neutrophils. We found that bestatin, an inhibitor of CD13/aminopeptidase N, enhanced the sensitivity of APL NB4 cells to ATRA at concentrations of 0.1–1000 ng/ml. A structurally different aminopeptidase N inhibitor, actinonin, also increased the effect of ATRA on differentiation, but an inactive stereoisomer of bestatin, (2R,3S)-AHPA-(R)-Leu, did not. Bestatin synergistically enhanced the cytostatic effect of ATRA on NB4 cells. Masking of the cell-surface CD13 by anti-CD13 antibody WM15 blocked the synergistic effect of bestatin and ATRA on differentiation. Thus bestatin, an immunomodulator clinically used for nonlymphocytic leukemia, synergistically increased the ATRA-induced differentiation of NB4 cells by inhibiting CD13/aminopeptidase N on the cell-surface.     

急性早幼粒细胞白血病凝血紊乱机制及诱导治疗期间凝血纤溶参数的变化

急性早幼粒细胞白血病（acute promyelocytic leukemia,APL）患者极易发生出血及血栓并发症,其凝血紊乱的临床表现和实验室检查特征与传统的脓毒性弥散性血管内凝血明显不同。研究认为APL凝血紊乱的主要发生机制包括外源凝血通路激活和原发纤溶亢进,直接依据包括组织因子、癌性促凝物及膜联蛋白Ⅱ表达增加。常见的诱导缓解药物有全反式维甲酸、亚砷酸及蒽环类药物为主的化疗,且各疗法诱导治疗过程中凝血纤溶参数的变 化各有差异。现就APL凝血紊乱发生机制的研究进展及诱导治疗期间凝血纤溶参数的变化作一综述。     

Regulatory role of the transforming growth factor-β signaling pathway in the drug resistance of gastrointestinal cancers

Gastrointestinal (GI) cancer, including esophageal, gastric, and colorectal cancer, is one of the most prevalent types of malignant carcinoma and the leading cause of cancer-related deaths. Despite significant advances in therapeutic strategies for GI cancers in recent decades, drug resistance with various mechanisms remains the prevailing cause of therapy failure in GI cancers. Accumulating evidence has demonstrated that the transforming growth factor (TGF)-β signaling pathway has crucial, complex roles in many cellular functions related to drug resistance. This review summarizes current knowledge regarding the role of the TGF-β signaling pathway in the resistance of GI cancers to conventional chemotherapy, targeted therapy, immunotherapy, and traditional medicine. Various processes, including epithelial-mesenchymal transition, cancer stem cell development, tumor microenvironment alteration, and microRNA biogenesis, are proposed as the main mechanisms of TGF-β-mediated drug resistance in GI cancers. Several studies have already indicated the benefit of combining antitumor drugs with agents that suppress the TGF-β signaling pathway, but this approach needs to be verified in additional clinical studies. Moreover, the identification of potential biological markers that can be used to predict the response to TGF-β signaling pathway inhibitors during anticancer treatments will have important clinical implications in the future.     

亚硒酸钠和维甲酸联合对HL－60细胞生长、分化的影响

 以人早幼粒白血病细胞（HL－60）为实验对象，观察了亚硒酸钠和维甲酸联合作用对其生长、分化的影响。结果表明：5.8μmol/L亚硒酸钠和0.1μmol/L维甲酸联合可显著抑制细胞生长，且细胞毒性并无增加，强于两者的单独作用。而且可明显诱导细胞向粒系细胞分化，在处理5天后有72%的细胞进行分化。单用0.1μmol/L维甲酸只有39%的细胞分化成熟。NBT还原实验表现出类似结果。