黄芪甲苷和齐墩果酸对体外神经干细胞增殖和Jagged1 mRNA表达的影响

目的 观察黄芪甲苷和齐墩果酸对体外神经干细胞增殖和相关基因Jagged1表达的影响。方法 采用机械吹打法从胎鼠脑内获得神经干细胞,随机分组,分别给予不同浓度(10^-6,5×10^-7,10^-7,5×10^-8,10^-8,5×10^-9,10^-9 mol·L^-1)的黄芪甲苷、齐墩果酸进行干预,72 h后用WST法检测细胞的增殖情况,PCR检测Jagged1表达水平。结果 黄芪甲苷对体外神经干细胞增殖影响不显著,高剂量尚存在细胞毒性。齐墩果酸能促进神经干细胞增殖,且呈一定的剂量效应关系,与对照组和黄芪甲苷组比较均有显著差异(P<0.05)。细胞未分化状态下Jagged1基因存在一定的表达,增殖率越高Jagged1表达水平越高;与同浓度黄芪甲苷组比较,齐墩果酸显著上调Jagged1表达(P<0.05)。结论 不同浓度的黄芪甲苷和齐墩果酸对体外培养神经干细胞增殖和Jagged1表达的影响不同;齐墩果酸作用优于黄芪甲苷。     

七氟醚预处理对全身缺氧损伤小鼠脑NO含量和NOS活性的影响

目的观察七氟醚(Sev)预处理后全身缺氧损伤小鼠的生存状况,测定脑内一氧化氮(NO)含量及一氧化氮合酶(NOS)活性,探讨七氟醚预处理的保护作用。方法 6~7周龄健康雄性昆明小鼠120只,随机分为3组:Sev 0.5 h组、Sev 24 h组及对照组(P组),每组40只。Sev 0.5 h组吸入1.0%Sev 30 min,在空气中洗脱30 min后放入体积分数5%O2+95%N2环境中持续20 min;Sev 24 h组每天吸入体积分数1.0%Sev30 min,连续2 d,第3天放入体积分数5%O2+95%N2环境中持续20 min;P组不吸入Sev,直接放入体积分数5%O2+95%N2环境中持续20 min。观察小鼠在体积分数5%O2环境中20 min内的生存时间、生存率,测定脑组织NO含量和NOS活性。结果与P组比较,Sev 0.5 h组小鼠生存率提高、生存时间延长(P<0.05),脑组织NO含量降低,NOS活性增高(P<0.05);而Sev 24 h组与P组比较差异无统计学意义(P>0.05)。Sev 0.5 h组与Sev 24 h组比较,生存率提高,生存时间延长(P<0.05),NO含量和NOS活性差异有统计学意义(P<0.05)。结论 Sev预处理能对全身缺氧损伤小鼠产生保护作用,通过即刻效应提高小鼠在低氧环境中的生存率,延长其生存时间,降低脑组织中的NO含量,提高NOS活性,减轻脑组织缺氧损伤。     

腺病毒转染的肝细胞生长因子对冠心病患者外周造血干细胞的动员作用

目的 探讨经冠状动脉内注射腺病毒（adenovirus,Ad,）转染人肝细胞生长因子（HGF）对严重冠状动脉狭窄患者外周造血干细胞的动员作用。方法 本研究人选18例冠心病患者,分为两组：给药组9例,经冠状动脉注入Ad5-HGF;对照组9例,经冠状动脉注入同等量的生理盐水。所有患者均于冠状动脉造影术前、术后6h、24h及6天抽取外周血,并应用流式细胞仪单克隆荧光抗体标记法检测其外周造血干细胞表面抗原CD34^＋、CD38^＋及CD117^＋。结果 给药组术后6h的CD34^＋明显高于对照组（0,104±0．082比0．022±0．012,P=0．021）,0h、24h及6天的CD34^＋两组之间差异无统计学意义;给药组术后6天的CD117^＋明显高于对照组（0．058±0．058比0．012±0．009,P=0,034）,差异有统计学意义,其余时间点两组间差异均无统计学意义;CD38^＋在各时间点两组间差异均无统计学意义。结论 经冠状动脉内注射转染A5-HGF可能在短时间内引起外周造血干细胞的动员。动员外周造血干细胞可能是HGF参与血管新生和器官组织损伤修复及抗凋亡、改善心功能的一个重要机制。     

Caspase-8和Bcl-2在脑肿瘤干细胞肿瘤坏死因子相关凋亡诱导配体耐药中的作用研究

 目的 探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)对脑肿瘤干细胞生长的影响,研究Caspase-8和Bcl-2在肿瘤坏死因子相关凋亡诱导配体耐药中的作用。方法 应用CD133免疫磁珠分选法获得脑肿瘤干细胞,流式细胞术检测分选阳性率;亚神经球形成实验分析脑肿瘤干细胞的自我更新能力和增殖能力;四甲基偶氮唑盐法检测肿瘤坏死因子相关凋亡诱导配体对脑肿瘤干细胞生长的影响;Western blot法检测DR5、FADD、Caspase-8和Bcl-2蛋白的表达。结果 分选后CD133⁺细胞即脑肿瘤干细胞可达71%;脑肿瘤干细胞以神经球的方式生长;肿瘤坏死因子相关凋亡诱导配体作用前后,脑肿瘤干细胞都有极强的形成神经球的能力;肿瘤坏死因子相关凋亡诱导配体可以引起脑肿瘤干细胞死亡,加入Caspase-8或Caspases抑制剂,可明显阻断肿瘤坏死因子相关凋亡诱导配体所引起的细胞死亡(P<0.05);Western blot结果显示,脑肿瘤干细胞表达Caspase-8 蛋白水平降低,表达Bcl-2蛋白水平增加(P<0.05)。结论 脑肿瘤干细胞是脑肿瘤对肿瘤坏死因子相关凋亡诱导配体耐药的根源,Caspase-8蛋白表达减少及Bcl-2蛋白表达增强使Caspase-8不能活化,导致了脑肿瘤干细胞发生肿瘤坏死因子相关凋亡诱导配体耐药。     

Traitement systémique des métastases cérébrales de mélanome

Melanomas have a high rate of brain metastases. Both the functional prognosis and the overall survival are poor in these patients. Until now, surgery and radiotherapy represented the two main modalities of treatment. Nevertheless, due to the improvement in the management of the extracerebral melanoma, the systemic treatment may be an option in patients with brain metastases. Immunotherapy with anti-CTLA4 (cytotoxic T-lymphocyte-associated protein 4) – ipilimumab – or BRAF (serine/threonine-protein kinase B-raf) inhibitors – vemurafenib, dabrafenib – has shown efficacy in the management of brain metastases in a- or pauci-symptomatic patients. Studies are ongoing with anti-PD1 (programmed cell death 1) and combinations of targeted therapies associating anti-RAF (raf proto-oncogene, serine/threonine kinase) and anti-MEK (mitogen-activated protein kinase kinase).     

EGFR inhibitors prevent induction of cancer stem-like cells in esophageal squamous cell carcinoma by suppressing epithelial-mesenchymal transition

There exists a highly tumorigenic subset of esophageal squamous cell carcinoma (ESCC) cells defined by high expression of CD44. A novel therapy targeting these cancer stem-like cells (CSCs) is needed to improve prognosis of ESCC. CSCs of ESCC have a mesenchymal phenotype and epithelial-mesenchymal transition (EMT) is critical to enrich and maintain CSCs. EGFR, frequently overexpressed in ESCC, has pivotal roles in EMT induced by TGF-β in invasive fronts. Thus, EMT in invasive fronts of ESCC might be important for CSCs and EGFR could be a target of a novel therapy eliminating CSCs. However, effects of EGFR inhibitors on CSCs in ESCC have not been fully examined. EGFR inhibitors, erlotinib and cetuximab, significantly suppressed enrichment of CSCs via TGF-β1-mediated EMT. Importantly, EGFR inhibitors sharply suppressed ZEB1 that is essential for EMT in ESCC. Further, EGFR inhibitors activated Notch1 and Notch3, leading to squamous cell differentiation. EGFR inhibition may suppress expression of ZEB1 and induce differentiation, thereby blocking EMT-mediated enrichment of CSCs. In organotypic 3D culture, a form of human tissue engineering, tumor cells in invasive nests showed high expression of CD44. Erlotinib significantly blocked invasion into the matrix and CD44 high expressing CSCs were markedly suppressed by erlotinib in organotypic 3D culture. In conclusion, EMT is a critical process for generation of CSCs and the invasive front of ESCC, where EMT occurs, might form a CSC niche in ESCC. EGFR inhibitors could suppress EMT in invasive fronts and be one therapeutic option targeting against generation of CSCs in ESCC.     

Adult mouse subventricular zones stimulate glioblastoma stem cells specific invasion through CXCL12/CXCR4 signaling

Background

Patients with glioblastoma multiforme (GBM) have an overall median survival of 15 months. This catastrophic survival rate is the consequence of systematic relapses that could arise from remaining glioblastoma stem cells (GSCs) left behind after surgery. We previously demonstrated that GSCs are able to escape the tumor mass and specifically colonize the adult subventricular zones (SVZs) after transplantation. This specific localization, away from the initial injection site, therefore represents a high-quality model of a clinical obstacle to therapy and relapses because GSCs notably retain the ability to form secondary tumors.

Method

In this work, we questioned the role of the CXCL12/CXCR4 signaling in the GSC-specific invasion of the SVZs.

Results

We demonstrated that both receptor and ligand are respectively expressed by different GBM cell populations and by the SVZ itself. In vitro migration bio-assays highlighted that human U87MG GSCs isolated from the SVZs (U87MG-SVZ) display stronger migratory abilities in response to recombinant CXCL12 and/or SVZ-conditioned medium (SVZ-CM) compared with cancer cells isolated from the tumor mass (U87MG-TM). Moreover, in vitro inhibition of the CXCR4 signaling significantly decreased the U87MG-SVZ cell migration in response to the SVZ-CM. Very interestingly, treating U87MG-xenografted mice with daily doses of AMD3100, a specific CXCR4 antagonist, prevented the specific invasion of the SVZ. Another in vivo experiment, using CXCR4-invalidated GBM cells, displayed similar results.

Conclusion

Taken together, these data demonstrate the significant role of the CXCL12/CXCR4 signaling in this original model of brain cancer invasion.     

Recent advances in the treatment of adult T‐cell leukemia‐lymphomas

Recent advances in treatment for adult T‐cell leukemia‐lymphoma (ATL) are reviewed herein. It is currently possible to select a therapeutic strategy for ATL and predict prognosis by classification of patients by clinical subtypes and clinicopathological factors. Although the overall survival (OS) of patients with ATL has increased marginally because of advances in chemotherapy, further prolongation of survival might be difficult with conventional chemotherapy alone. Promising results have been reported for antiviral therapy using zidovudine and interferon‐α, and, indeed, antiviral therapy is currently the standard treatment for patients with ATL in western countries. Remarkably, the 5‐year OS rates are 100% for both the smoldering‐type and chronic‐type ATL. Recently, treatments for ATL have included allogeneic hematopoietic stem cell transplantation and molecular targeted therapies. Furthermore, the anti‐CCR4 monoclonal antibody mogamulizumab has been shown to have marked cytotoxic effects on ATL cells, especially in the leukemic type of ATL. In the lymphoma type of ATL, the response rate may be improved by combining mogamulizumab with chemotherapy. It should be recognized that prevention of infection from carriers of human T‐cell leukemia virus type‐I and transfer of the virus from mother to infant are crucial issues for the eradication of ATL.     

Changing trends in prognostic factors for patients with multiple myeloma after autologous stem cell transplantation during the immunomodulator drug/proteasome inhibitor era

We evaluated the clinical significance of prognostic factors including the International Staging System (ISS) and modified European Group for Blood and Marrow Transplantation response criteria in 1650 Japanese patients with multiple myeloma (MM) who underwent upfront single autologous stem cell transplantation (ASCT). We categorized patients into two treatment cohorts: pre‐novel agent era (1995–2006) and novel agent era (2008–2011). The combined percentage of pre‐ASCT complete response and very good partial response cases (463 of 988, 47%) significantly increased during the novel agent era compared with the pre‐novel agent era (164 of 527, 31%; P < 0.0001). The 2‐year overall survival (OS) rate of 87% during the novel agent era was a significant improvement relative to that of 82% during the pre‐novel agent era (P = 0.019). Although significant differences in OS were found among ISS stages during the pre‐novel agent era, no significant difference was observed between ISS I and II (P = 0.107) during the novel agent era. The factors independently associated with a superior OS were female gender (P = 0.002), a good performance status (P = 0.024), lower ISS (P < 0.001), pre‐ASCT response at least partial response (P < 0.001) and ASCT during the novel agent era (P = 0.017). These results indicate that the response rate and OS were significantly improved, and the ISS could not clearly stratify the prognoses of Japanese patients with MM who underwent upfront single ASCT during the novel agent era.