高三尖杉酯碱在慢性髓性白血病治疗中的作用机制

酪氨酸激酶抑制剂(TKIs)的出现,通过降低疾病进展的风险,大大提高了慢性髓性白血病(CML)患者的疗效,延长了患者的生存期,但对于进入疾病进展期患者疗效仍较差。而高三尖杉酯碱(HHT)在治疗进展/耐药的CML患者疗效显著。该文就HHT在CML治疗中的作用机制作一简要综述,旨在为CML的治疗提供实验依据和临床参考。     

3q26重排在慢性髓细胞白血病中的临床特征及预后

目的评估慢性髓细胞白血病(chronicmyeloid leukemia,CML)中3q26重排患者的临床及预后。方法对2010年至2016年确诊为CML的1 075例患者进行回顾性分析,将其分为3q26重排阳性组(n=19)与3q26重排阴性组(n=1 056),比较两组EVI1表达、ABL激酶区突变并分析其生存差异。同时比较3种治疗方式[酪氨酸激酶抑制剂(tyrosine kinase inhibitors,TKIs)、TKIs联合化疗、异基因造血干细胞移植]对3q26重排阳性患者的预后影响。结果 3q26重排患者多处于进展期(χ~2=181.233,P0.01),进入急变期的中位时间较短(9.5个月)。3q26重排阳性组ABL激酶区突变比例(χ~2=16.758,P0.01)及EVI1表达量(Z/U=-0.331 9,P0.01)均明显高于阴性组。经TKIs治疗后,3q26重排阳性组患者中位生存时间较阴性组患者明显缩短(χ~2=313.229,P0.01);造血干细胞移植组患者较TKIs治疗组预后好(P=0.049)。结论 3q26重排阳性CML患者急变风险高,时间短,预后差,造血干细胞移植可能改善其预后。     

慢性粒细胞白血病一线治疗药物研究进展

第一代BCR-ABL酪氨酸激酶抑制剂(tyrosine kinase inhibitors,TKIs)伊马替尼(Imatinib)是慢性粒细胞白血病(chronic myeloid leukemia,CML)慢性期的一线标准治疗.伊马替尼通过直接靶向作用于Bcr-Abl激酶,极大改善了CML病程.近期,第二代TKIs药物尼洛替尼(Nilotinib)和达沙替尼(Dasatinib)又被美国FDA批准为CML的一线治疗.本文主要就CML一线治疗的进展作一综述.     

慢性髓系白血病的免疫研究进展

慢性髓系白血病(CML)是最易受免疫控制的恶性疾病之一.CML患者都存在不同程度的免疫缺陷,主要表现为NK细胞,T细胞,间充质干细胞和树突状细胞等数量和功能缺陷.CML初诊时的免疫改变可能反映了患者在免疫缺陷状态下对白血病相关抗原(LAA)残存的反应,酪氨酸激酶抑制剂(TKIs)极大地改善了CML的预后,干扰素α(IFN-α)等治疗也会对免疫功能产生影响.     

表皮生长因子受体突变非小细胞肺癌耐药机制的研究进展

目前，肺癌的发病率及病死率仍居全球各类癌症的首位。肺癌确诊时常为中晚期，放化疗疗效不理想，术后复发与转移率较高。靶向治疗，如表皮生长因子受体(epidermal growth factor receptor,EGFR)酪氨酸激酶抑制剂(tyrosine kinase inhibitors,TKIs)的应用，显著提高了伴EGFR突变的中晚期非小细胞肺癌(non-small cell lung cancer,NSCLC)患者的临床疗效。但由于耐药的发生，NSCLC患者预后仍然欠佳。本文对EGFR突变的NSCLC患者对TKIs耐药机制的研究进展作一综述，以期为临床探索新的解决策略提供依据。     

慢性髓性白血病患者门诊酪氨酸激酶抑制剂治疗规范化管理

21世纪以来,酪氨酸激酶抑制剂(TKI)在治疗慢性髓性白血病(CML)方面取得了极大的成功,使慢性髓性白血病-慢性期(CML-CP)成为一种可控制的慢性疾病.接受TKI治疗的CML患者大多数在门诊随诊监测,因此,患者的依从性及对疾病的认知能力;医师优化临床TKI选择、早期疾病监测、治疗疗效的评估等对实现免治疗缓解最终彻底清除CML干细胞方面有着重要作用.现就CML患者门诊接受TKI的规范化治疗及监测进行概述.     

慢性粒细胞白血病患者酪氨酸激酶抑制剂的耐药管理

酪氨酸激酶抑制剂(TKI)的应用使慢性粒细胞白血病(CML)的治疗发生了革命性的变化,但是随着其在临床中的广泛应用,耐药成为临床治疗中面临的巨大挑战.二代、三代TKI.及某些新型药物的研发给一代TKI伊马替尼(IM)耐药的患者带来了新的治疗选择和希望.不断完善的疗效监测体系和ABL激酶区突变检测的应用为TKI的选择、疗效评价,以及药物转换提供了客观且敏感的指标.因此,只有将治疗药物与相应的监测体系相结合,才能使CML患者得到更为合理和规范的治疗.本文拟就CML患者使用TKI耐药后,治疗方案选择及疗效监测体系的研究进展进行阐述.     

慢性粒细胞白血病错配修复基因的研究

目的 探讨慢性粒细胞白血病（CML）错配修复（MMR）基因的表达水平及调控机制。方法 用半定量RT-PCR方法检测62例CML患者及K562细胞的5个MMR基因（hMSH2、hMSH3、hMSH6、hMLH1、hPMS2）mRNA的表达；用RT-PCR方法动态检测26例进行异基因外周血造血干细胞移植（allo-PBSCT）及4例使用伊马替尼治疗的CML患者ber-abl及MMR mRNA的表达水平；用伊马替尼体外作用于CML患者的单个核细胞（MNC）及K562细胞后，用Western blot方法检测BCR—ABL融合蛋白的酪氨酸磷酸化水平，RT-PCR方法检测MMR mRNA表达水平。结果 与正常人比较，CML患者及K562细胞的hMSH2、hMSH3、hMLH1 mRNA的表达明显降低（P〈0．05）；26例行allo—PBSCT及4例使用伊马替尼治疗的CML患者，其hMSH2、hMSH3、hMLH1 mRNA的表达随着bcr—abl mRNA的表达降低而升高；伊马替尼体外作用于CML患者MNC及K562细胞后，其hMSH2、hMSH3、hMLH1 mRNA的表达随着BCR—ABL融合蛋白酪氨酸磷酸化水平的降低而升高。结论 CML患者、K562细胞hMSH2、hMSH3、hMLH1 mRNA比正常人降低，bcr—abl融合基因抑制hMSH2、hMSH3、hMLH1 mRNA的表达。     

奥希替尼治疗T790M突变的晚期肺腺癌1例并文献复习

在肺癌的驱动基因中,表皮生长因子(epidermal growth factor receptor,EGFR)是其最常见的驱动基因之一。在EGFR突变阳性的患者中,一线使用表皮生长因子受体酪氨酸激酶抑制剂(epidermal growth factor receptor-tyrosine kinase inhibitors,EGFR-TKIs)(例如吉非替尼、埃克替尼、阿法替尼等)口服治疗,已经体现出良好的疗效。但大多数患者在服用初始一线的TKIs治疗后出现T790M突变,引起耐药,导致疾病进展。嘉兴市第二医院呼吸与危重症医学科收治的1例EGFR突变阳性患者,在使用吉非替尼片口服治疗1年后,出现疾病进展。行基因检测后提示T790M突变阳性,改奥希替尼口服。目前患者疗效评价为部分缓解。奥希替尼对于出现T790M突变患者的治疗,有着稳定的疗效。早期及时将临床、病理和分子诊断学技术联合起来对患者治疗进行全程管理,可以为晚期非小细胞肺癌患者的治疗提供强有力的保障。     

2013年慢性粒细胞白血病和其他慢性骨髓增殖性肿瘤的研究进展

酪氨酸激酶抑制剂(TKIs)已成为治疗慢性粒细胞白血病的首选治疗药物,目前3种TKIs可用于一线选择,如何选择一线TKIs、当治疗失败或不耐受时又如何转换治疗、如何进行分子学监测和及时判断治疗失败的高危患者仍是困扰临床医生的一些问题.其他慢性骨髓增殖性肿瘤中除Janus激酶(JAK)突变以外很多新的基因突变被发现,(JAK)抑制剂ruxolitinib已应用于骨髓纤维化的治疗,其他多种JAK抑制剂也已进入临床试验.其剂量及安全性以及如何最大限度减少骨髓抑制是临床医生面临的问题.现就上述内容做一综述.     

BCR-ABL kinase is dead; long live the CML stem cell

Chronic myeloid leukemia (CML) is a hematopoietic disease characterized by expansion of myeloid blood cells. It is caused by the t(9;22) chromosomal translocation that results in the expression of the fusion tyrosine kinase BCR-ABL. Tyrosine kinase inhibitor (TKI) therapy has led to long-term remissions, but patients remain BCR-ABL+. There is agreement that TKIs do not kill CML stem cells; however, it is controversial whether this is because of a lack of BCR-ABL kinase inhibition in CML stem cells or because CML stem cells do not require BCR-ABL for survival. In this issue of the JCI, Corbin and colleagues provide definitive evidence that BCR-ABL is kinase active in CML stem cells and that TKIs inhibit this kinase activity without affecting CML stem cell survival. Rather, CML stem cells revert to a normal dependence on cytokines for survival and proliferation. These results demonstrate that the CML stem cell is not BCR-ABL addicted and have important implications for developing curative therapeutic approaches to CML.     

BCL6-mediated repression of p53 is critical for leukemia stem cell survival in chronic myeloid leukemia

Chronic myeloid leukemia (CML) is induced by the oncogenic BCR-ABL1 tyrosine kinase and can be effectively treated for many years with tyrosine kinase inhibitors (TKIs). However, unless CML patients receive life-long TKI treatment, leukemia will eventually recur; this is attributed to the failure of TKI treatment to eradicate leukemia-initiating cells (LICs). Recent work demonstrated that FoxO factors are critical for maintenance of CML-initiating cells; however, the mechanism of FoxO-dependent leukemia initiation remained elusive. Here, we identified the BCL6 protooncogene as a critical effector downstream of FoxO in self-renewal signaling of CML-initiating cells. BCL6 represses Arf and p53 in CML cells and is required for colony formation and initiation of leukemia. Importantly, peptide inhibition of BCL6 in human CML cells compromises colony formation and leukemia initiation in transplant recipients and selectively eradicates CD34(+) CD38(-) LICs in patient-derived CML samples. These findings suggest that pharmacological inhibition of BCL6 may represent a novel strategy to eradicate LICs in CML. Clinical validation of this concept could limit the duration of TKI treatment in CML patients, which is currently life-long, and substantially decrease the risk of blast crisis transformation.     

Targeting autophagy potentiates tyrosine kinase inhibitor–induced cell death in Philadelphia chromosome–positive cells, including primary CML stem cells

Imatinib mesylate (IM), a potent inhibitor of the BCR/ABL tyrosine kinase, has become standard first-line therapy for patients with chronic myeloid leukemia (CML), but the frequency of resistance increases in advancing stages of disease. Elimination of BCR/ABL-dependent intracellular signals triggers apoptosis, but it is unclear whether this activates additional cell survival and/or death pathways. We have shown here that IM induces autophagy in CML blast crisis cell lines, CML primary cells, and p210^BCR/ABL-expressing myeloid precursor cells. IM-induced autophagy did not involve c-Abl or Bcl-2 activity but was associated with ER stress and was suppressed by depletion of intracellular Ca²⁺, suggesting it is mechanistically nonoverlapping with IM-induced apoptosis. We further demonstrated that suppression of autophagy using either pharmacological inhibitors or RNA interference of essential autophagy genes enhanced cell death induced by IM in cell lines and primary CML cells. Critically, the combination of a tyrosine kinase inhibitor (TKI), i.e., IM, nilotinib, or dasatinib, with inhibitors of autophagy resulted in near complete elimination of phenotypically and functionally defined CML stem cells. Together, these findings suggest that autophagy inhibitors may enhance the therapeutic effects of TKIs in the treatment of CML.     

PP2A-activating drugs selectively eradicate TKI-resistant chronic myeloid leukemic stem cells

The success of tyrosine kinase inhibitors (TKIs) in treating chronic myeloid leukemia (CML) depends on the requirement for BCR-ABL1 kinase activity in CML progenitors. However, CML quiescent HSCs are TKI resistant and represent a BCR-ABL1 kinase–independent disease reservoir. Here we have shown that persistence of leukemic HSCs in BM requires inhibition of the tumor suppressor protein phosphatase 2A (PP2A) and expression — but not activity — of the BCR-ABL1 oncogene. Examination of HSCs from CML patients and healthy individuals revealed that PP2A activity was suppressed in CML compared with normal HSCs. TKI-resistant CML quiescent HSCs showed increased levels of BCR-ABL1, but very low kinase activity. BCR-ABL1 expression, but not kinase function, was required for recruitment of JAK2, activation of a JAK2/β-catenin survival/self-renewal pathway, and inhibition of PP2A. PP2A-activating drugs (PADs) markedly reduced survival and self-renewal of CML quiescent HSCs, but not normal quiescent HSCs, through BCR-ABL1 kinase–independent and PP2A-mediated inhibition of JAK2 and β-catenin. This led to suppression of human leukemic, but not normal, HSC/progenitor survival in BM xenografts and interference with long-term maintenance of BCR-ABL1–positive HSCs in serial transplantation assays. Targeting the JAK2/PP2A/β-catenin network in quiescent HSCs with PADs (e.g., FTY720) has the potential to treat TKI-refractory CML and relieve lifelong patient dependence on TKIs.     

尼洛替尼治疗伴V299L突变的慢性髓性白血病二例

本研究提高对尼洛替尼治疗伊马替尼耐药伴V299L突变的慢性髓系白血病（chronicmyeloidleukemia,CML）患者的临床认识。收集我院2例伴V299L突变的CML患者尼洛替尼治疗前后的骨髓标本,采用巢式PCR扩增并测序的方法检测A砚突变,分析临床特征。结果表明,2例伊马替尼耐药的CML患者均发生V299L突变,1例经尼洛替尼治疗6个月后V299L突变转为阴性,并取得完全血液学缓解;另1例经尼洛替尼治疗7个月后V299L突变转为阴性,并取得明显分子学缓解。结论：尼洛替尼治疗伊马替尼耐药伴V299L突变的CML患者安全性和疗效令人满意。     

Adherence trajectories in oral therapy for chronic myeloid leukemia: Overview of a research protocol

Over a quarter of chemotherapy regimens now include oral agents. Individuals living with cancer are now responsible for administering this lifesaving therapy at home by taking every dose as prescribed. One type of oral chemotherapy, tyrosine kinase inhibitors (TKIs), is the current recommended treatment for chronic myeloid leukemia. This targeted therapy has markedly improved survival but comes with significant side effects and financial costs. In the study described in this protocol, the investigators seek to understand the dynamic nature of TKI adherence experienced by individuals diagnosed with CML. Using a mixed-method approach in this prospective observational study, funded by the National Cancer Institute, we seek to describe subjects' adherence trajectories over 1 year. We aim to characterize adherence trajectories in individuals taking TKIs using model-based cluster analysis. Next, we will determine how side effects and financial toxicity influence adherence trajectories. Then we will examine the influence of TKI adherence trajectories on disease outcomes. Additionally, we will explore the experience of patients taking TKIs by interviewing a subset of participants in different adherence trajectories. The projected sample includes 120 individuals taking TKIs who we will assess monthly for 12 months, measuring adherence with an objective measure (Medication Event Monitoring System). Identifying differential trajectories of adherence for TKIs is important for detecting subgroups at the highest risk of nonadherence and will support designing targeted interventions. Results from this study can potentially translate to other oral agents to improve care across different types of cancer.     

Dual targeting of EGFR can overcome a major drug resistance mutation in mouse models of EGFR mutant lung cancer

EGFR is a major anticancer drug target in human epithelial tumors. One effective class of agents is the tyrosine kinase inhibitors (TKIs), such as gefitinib and erlotinib. These drugs induce dramatic responses in individuals with lung adenocarcinomas characterized by mutations in exons encoding the EGFR tyrosine kinase domain, but disease progression invariably occurs. A major reason for such acquired resistance is the outgrowth of tumor cells with additional TKI-resistant EGFR mutations. Here we used relevant transgenic mouse lung tumor models to evaluate strategies to overcome the most common EGFR TKI resistance mutation, T790M. We treated mice bearing tumors harboring EGFR mutations with a variety of anticancer agents, including a new irreversible EGFR TKI that is under development (BIBW-2992) and the EGFR-specific antibody cetuximab. Surprisingly, we found that only the combination of both agents together induced dramatic shrinkage of erlotinib-resistant tumors harboring the T790M mutation, because together they efficiently depleted both phosphorylated and total EGFR. We suggest that these studies have immediate therapeutic implications for lung cancer patients, as dual targeting with cetuximab and a second-generation EGFR TKI may be an effective strategy to overcome T790M-mediated drug resistance. Moreover, this approach could serve as an important model for targeting other receptor tyrosine kinases activated in human cancers.     

药物基因组学在慢性髓细胞白血病靶向治疗中的研究进展

慢性髓细胞白血病(CML)是骨髓造血干细胞克隆性增殖引起的血液系统恶性疾病,其治疗方案以药物治疗为主.近年,随着靶向药物酪氨酸激酶抑制剂(TKI)的广泛应用,CML患者的预后得到显著提高.但是CML患者接受靶向治疗后,在治疗反应、耐药及不良反应等方面存在较大的个体差异.相关研究者推测,CML患者对靶向治疗的个体间差异与遗传因素有关.因此,研究遗传因素与TKI疗效之间关系的药物基因组学,成为近年CML靶向治疗的研究热点之一.笔者拟就CML靶向治疗中,与靶向药物TKI的代谢和转运相关基因的药物基因组学研究进展进行综述.