结肠癌Lovo细胞RUNX3基因的表达与其增殖及凋亡的关系

目的:探讨5-氮-2'-脱氧胞苷(5-Aza-CdR)对人结肠癌Lovo细胞增殖凋亡及抑癌基因RUNX3表达的影响.方法:用特异性甲基转移酶抑制剂5-Aza-CdR0.4,4,40 μmol/L处理人结肠癌细胞株Lovo 3d,继续常规培养5d后,采用四唑盐法(MTT)比色法观察细胞经药物处理前后的生长活性.以半定量RT-PCR检测细胞处理前后抑癌基因RUNX3 mRNA的表达,以甲基化特异性PCR(methylation-specific PCR,MSP)检测细胞处理前后RUNX3的甲基化状态,应用流式细胞仪进行细胞凋亡率的检测.结果:与对照组相比,0.4,4,40 μmol/L的5.Aza-CdR处理细胞后.细胞RUNX3mRNA的相对表达量(0.46±0.06,0.71±0.06,0.84±0.07 vs 0,P＜0.01)和细胞凋亡率均增高(10.95%±2.09%,17.61%±1.51%,26.60%±1.89%vs 2.92%±0.93%,P＜0.01).呈剂量依赖性(F=168.4,F=145.7),结肠癌Lovo细胞生长速率下降,RUNX3 mRNA重新表达,其基因启动子区域部分甲基化.结论:5-Aza-CdR可逆转RUNX3启动子高甲基化状态,抑制细胞生长,诱导部分细胞凋亡.     

槲皮素对结肠癌HT-29细胞增殖及周期的影响

目的:探讨槲皮素(Qu)对结肠癌HT-29细胞增殖和凋亡影响的分子机制．方法:以40×10-6,80×10-6,160×10-6mol／L的槲皮素作用结肠癌HT-29细胞,以溶剂为对照组,采用MTT试验、流式细胞分析、免疫细胞化学和RT-PCR等方法观察槲皮素对结肠癌细胞增殖,细胞周期,细胞凋亡,及Caspase-3 蛋白表达、Caspase-3、bcl-2、bax mRNA表达的影响．结果:40×10-6mol／L Qu明显促进HT-29细胞增殖(P<0．05),80×10-6,160×10-6mol／L Qu 明显抑制细胞增殖(P<0．05或P<0．01),呈时间 (?)效应．40×10-6,80×10-6,160×10-6mol/L槲皮素作用HT-29细胞72 h,其增殖率分别为 (111．8±9．6)％,(64．6±8.3)％和(26．1±5．7)％, G0／G1期细胞分别为(32．7±5．4)％、(58．1± 18．3)％和(71．6±20．8)％,S期细胞分别为(48．6 ±17．5)％、(27．4±13．4)％和(15．4±10．1)％,细胞凋亡率分别为(7．0±1．3)％、(15．6±3．6)％和(26．4±6．2)％,80×10-6,160×10-6mol／L能明显提高G0／G1期细胞(P<0．01),明显降低S期细胞(P<0．01),细胞凋亡明显增加(P<0．01)．80 ×10-6,160×10-6mol／L的Qu增加细胞中bax mRNA,Caspase-3 mRNA及其蛋白的表达,降低 bcl-2 mRNA的表达．40×10-6mol／L的Qu增加 Caspasc-3 mRNA表达,但其蛋白表达未见明显增加,细胞增殖明显增加．结论:槲皮素能促进结肠癌HT-29细胞增殖, 也能诱导细胞凋亡,其机制可能是通过上调 Caspase-3和bax表达,降低bcl-2表达来实现的．     

5-氮杂-2'-脱氧胞苷对人胃癌SGC-7901细胞株生长及EDNRB基因启动子异常甲基化的影响

目的:探讨去甲基化药物5-氮杂-2'-脱氧胞苷(5-Aza-CdR)对人胃癌细胞系SGC-7901细胞株的生长及EDNRB基因启动子异常甲基化的影响.方法:使用1、2、5、10μmol/L5-Aza-CdR干预胃癌SGC-7901细胞,甲基化特异性PCR(MSP)和逆转录聚合酶链反应(RT-PCR)分别检测药物干预前后EDNRB基因的甲基化状态和EDNRB mRNA的表达,MTT法检测细胞增殖活性,流式细胞术分析细胞周期及细胞凋亡的改变.结果:未经5-Aza-CdR处理的SGC-7901细胞中EDNRB基因启动子区域CpG岛高甲基化,且EDNRB mRNA不表达,经1、2、5、10μmol/L5-Aza-CdR处理4d后,EDNRB基因启动子区域高甲基化状态得到逆转,细胞中EDNRB mRNA表达恢复.4种浓度5-Aza-CdR处理的SGC-7901细胞后,细胞增殖受到抑制,且呈时间和剂量依赖性;并抑制SGC-7901细胞生长周期,其细胞周期阻滞于S期,5、10μmol/L5-Aza-CdR实验组细胞凋亡率显著高于对照组,且差异有统计学意义(7.13%±0.87%,13.34%±1.12% vs 3.69%±...     

5-Aza-CdR 对人卵巢癌3AO、SKOV3细胞增殖凋亡及抑癌基因RUNX3表达的影响

目的探讨5-氮-2’脱氧胞苷（5-Aza—CdR）对人卵巢癌3AO及SKOV3细胞增殖凋亡及抑癌基因RUNX3表达的影响。方法以浓度为0．5、5、50μmol／L的5-Aza—CdR处理人卵巢癌细胞株3AO及SKOV33d，常规培养5d后采用四唑盐（MTT）比色法观察细胞的生长活性，以半定量RT—PCR法检测抑癌基因RUNX3mRNA的表达，并用流式细胞仪检测细胞凋亡率。结果5-Aza—CdR能明显抑制肿瘤细胞生长，随5-Aza—CdR浓度增加，细胞生长速率下降；药物处理后RUNX3mRNA的表达明显高于处理前（P〈0．05），且存在明显剂量依赖性。5-Aza—CdR处理后3AO及SKOV3细胞凋亡率均高于处理前（P均〈0．05），细胞凋亡率与5-Aza—CdR剂量均呈正相关。结论5-Aza—CdR能使RUNX3基因去甲基化，增强其抑癌功能。     

5-氮杂-2′-脱氧胞苷对结肠腺癌细胞株Caco-2细胞生物学行为的影响

[目的]研究去甲基化5-氮杂-2′-脱氧胞苷(5-Aza-CdR)对人结肠腺癌细胞株Caco-2细胞生长周期及凋亡的影响,探讨其临床治疗的可能性。[方法]分别使用0.4、1.6、6.4、25.6、102.4μmol/L浓度的5-Aza-CdR处理Caco-2细胞;通过MTT检测5-Aza-CdR对Caco-2细胞存活率的影响;应用流式细胞检测5-Aza-CdR对Caco-2细胞生长周期及凋亡的影响;RT-PCR检测处理前后抑癌基因RASSF1A mRNA表达的改变。[结果]1.6μmol/L浓度的5-Aza-CdR可以明显的抑制Caco-2细胞的增殖,细胞周期中处于G0/G1期的细胞明显的增多,阻滞于G1期,凋亡率增高;5-Aza-CdR的作用与其浓度、时间在一定范围内呈正相关。5-Aza-CdR处理后,无RASSF1A表达的Caco-2细胞可检测出基因RASSF1A的重新表达。[结论]5-Aza-CdR可消除某些抑癌基因启动子甲基化状态,使其重新表达而抑制Caco-2细胞的生长,并促进其凋亡。     

5′-氮杂-2′-脱氧胞苷对T47D乳腺癌细胞生物学行为的影响

目的探讨去甲基化5′-氮杂-2′-脱氧胞苷（5-Aza-CdR）对T47D乳腺癌细胞株生长周期及凋亡的影响。方法分别使用浓度为0．5、1．0、2．0．5．0、25．0、100．0μmol／L 5-Aza-CdR处理T47D细胞株。MTT法检测T47D细胞存活率。流式细胞仪检测T47D细胞生长周期,观察细胞凋亡情况。RT—PCR法检测处理前后抑癌基因p16 mR—NA表达。结果5-Aza-CdR作用后T47D细胞明显受抑,G0／G1期细胞明显增多,细胞阻滞于G1期,凋亡率明显增高;5-Aza—CdR处理后无p16表达的T47D细胞检测出p16基因的重新表达。结论5-Aza—CdR可抑制T47D细胞的生长,并促进其凋亡;其机制可能为消除某些抑癌基因启动子甲基化。     

埃罗替尼对胰腺癌细胞BxPC3生长的影响及其机制

目的观察表皮生长因子受体（EGFR）抑制剂埃罗替尼对体外培养的胰腺癌细胞BxPC3生长的影响,并探讨其作用机制。方法应用MTT法检测埃罗替尼作用后BxPC3细胞的增殖情况;用流式细胞分析、透射电镜和原位末端标记（TUNEL）法观察细胞凋亡和细胞周期的变化;RT—PCR法检测细胞bcl-2、bax、bcl-xl、bak mRNA表达。结果埃罗替尼呈剂量和时间依赖性抑制BxPC3细胞生长。72h后,1、100μmol／L的埃罗替尼处理组细胞存活率分别为（90．25±2．62）％和（40．75±2．98）％。两者比较具有统计学意义（P〈0．01）。50μmol／L埃罗替尼处理BxPC3后24、96h的细胞存活率分别为（74．0±4．08）％和（49．50±1．29）％,两者比较也具有统计学意义（P〈0．01）。50μmol／L埃罗替尼处理组的细胞凋亡率为（11．0±1．1）％,显著高于对照组的（6．2±1．1）％（P〈0．01）;G0／G1细胞占（73．4±1．3）％,也显著高于对照组的（63．3±1．0）％;透射电镜可见细胞呈现明显凋亡形态,并见凋亡小体形成。埃罗替尼处理组细胞bcl-2、bcl—xl mRNA表达下调,bax mRNA表达轻微上调,bak mRNA的表达不受影响。结论EGFR抑制剂埃罗替尼体外可抑制胰腺癌细胞系BxPC3的生长,其机制可能与阻滞细胞周期,上调促凋亡蛋白和下调凋亡抑制蛋白有关.     

亚细胞毒性剂量As2O3增加胃癌细胞对rhTRAIL的敏感性及其机制

目的:研究亚细胞毒性剂量As2O3对rhTRAIL诱导胃癌细胞凋亡的影响及其机制．方法:人胃腺癌细胞株SGC 7901以As2O3(1μmol／L),rhTRAIL(500μg／L)及两者联用处理:采用AnnexinV-FITC和PI双染色流式细胞仪检测细胞凋亡:用间接免疫荧光染色结合流式细胞技术检测细胞表面TRAIL R1／DR4和TRAIL R2／DR5分子表达;RT-PCR方法检测TRAIL R1／DR4和TRAIL R2／DR5 mRNA表达．结果:rhTRAIL在单用或与As2O3联用时均可以诱导胃癌SGC7901细胞凋亡,并且随着作用时间延长(12-72 h),细胞凋亡率逐渐增高．As2O3与rhTRAIL联用24,48,72 h后,SGC7901细胞凋亡率分别显著高于单用rhTRAIL处理相同时间细胞(36．49％±7．12％,47．13％±3．44％,55．63％±7．16％vs 29．78％±3.18％、38．56％±1．89％,43．12％±6．23％,P<0．05); As2O3单用或联用rhTRAIL处理SGC7901细胞24 h后,细胞表面TRAIL R1／DR4和TRAIL R2／DR5分子的平均荧光密度(MFI)较对照组细胞显著增加(R1／DR4:29．44±4．29,26．14±3．40 vs13．45±3．81,P<0．05或P<0．01;R2／DR5:28．04±0．79．3 1．47±4．56vs16．45±5．07,P<0．05或P<0．01);与此同时,TRAIL R1／DR4和TRAIL R2／DR5mRNA表达水平增高．结论:亚细胞毒性剂量As2O3可能通过增加TRAIL R1／DR4和TRAIL R2／DR5基因表达、上调细胞表面TRAIL死亡受体从而增加胃癌细胞SGC7901对rhTRAIL的敏感性,两药可能联合用于治疗胃癌．     

丹参酮ⅡA对肝癌SMMC-7721细胞COX-2表达的影响

目的:观察丹参酮ⅡA对肝癌SMMC-7721细胞生长和凋亡的影响及其作用机制．方法:体外培养肝癌SMMC-7721细胞株,经丹参酮ⅡA(终浓度0．5 mg／L)作用后,采用四唑盐(MTT)比色法检测细胞增殖,透射电镜观察细胞凋亡,流式细胞仪检测细胞凋亡,免疫细胞化学SABC法检测COX-2蛋白表达,放射免疫法检测前列腺素E2(PGE2)含量．结果:丹参酮ⅡA对肝癌细胞的生长有明显的抑制作用,并呈剂量依赖性．以0．5 mg／L作用终浓度抑制作用最明显,其48 h的抑制率为 69．3％,与对照组相比差异有显著性(P<0．01)．电镜下观察,丹参酮ⅡA作用后肝癌细胞表现为细胞皱缩、核染色质浓缩、核碎裂以及凋亡小体形成等凋亡特征性的形态改变．5 mg/ L丹参酮ⅡA作用后,随时间的延长,凋亡率逐渐升高,48 h达到高峰,随后逐渐下降(24,48, 72 h凋亡率分别为7．45％±0．33％、6．59％± 0．45％、4．78％±1．05％),与对照组比较,各处理组都有显著性差异(均P<0．01),丹参酮作用组肝癌细胞COX-2表达明显减少,其培养液中 PGE2的产生量下降,与对照组相比差异均有显著性(P<0．01)．结论:丹参酮ⅡA可能是通过下调COX-2 mRNA的表达水平发挥其对肝癌细胞生长抑制及促进凋亡作用．     

环氧合酶-2对人肝癌细胞增殖和凋亡的调节作用

目的:观察环氧合酶-2(cyclooxygenase-2, COX-2)在肝癌细胞中表达,探讨COX-2抑制剂celecoxib对肝癌细胞增殖和凋亡的作用．方法:免疫细胞化学、逆转录聚合酶链反应(RT-PCR)方法研究COX-2在肝癌细胞株中表达;MTT法观察COX-2抑制剂对肝癌细胞增殖的影响;透射电镜及流式细胞仪观察 celecoxib诱导肝癌细胞凋亡的作用、对细胞周期的影响及MDR1／P-gp表达的变化;用RTPCR 方法检测Survivin mRNA药物处理后表达的变化．结果:celecoxib对肝癌细胞抑制增殖、诱导凋亡呈时间和剂量依赖性．celecoxib作用HepG2 48 h抑制率为70．98％±0．67％(200 μmol／L)、 47．93％±1．08％(100 μmol／L);Bel-7402为 57．29％±0．67％(200 μmol／L)、43．84％± 0．86％(100 μmol／L);同样浓度但作用20 h, HepG2为45．51％±1．35％(200 μmol／L), 14.35％±1．55％(100 μmol／L);Bel-7402则为34．35％±0．63％(200 μmol／L),15．35％± 0．88％(100 μmol／L),不同浓度以及不同作用时间相比均有显著差异(P<0．01);100 μmol／L celecoxib作用24,48,72,96 h的肝癌细胞凋亡率分别为12．2％±2．44％,4．0％±1．67％,20．4％±4．38％,57．9％±5．74％(HepG2)和3．0％± 1．05％,18．5％±3．51％,29.3％±3．25％,48．4％±4．77％(Bel-7402),与对照组相比有显著差异(P<0．01);细胞周期分布改变,G0／G1期细胞比例增加,24,48,72 h分别为:44．17％±1．01％,59．60％±0．61％,62．7％±1．22％ (HepG2)和47．80％±0．41％,58．60％±0．46％, 78．40％±1．95％(Bel-7402),与对照组比较有显著差异(P<0．01);对照组PCNA蛋白表达呈强阳性( ),经药物处理后表达减弱,并随时间延长而显著;HepG2中COX-2蛋白表达明显弱于Bel-7402,药物处理后表达也不同．Survivin在肝癌细胞株中呈高表达状态, celecoxib作用48 h mRNA表达降至零,而72 h 后表达水平又有上升;两株肝癌细胞中经 celecoxib处理后,MDR1／P-gp表达有降低的趋势(Bel-7402),或是基本上不受影响(HepG2)．结论:COX-2抑制剂celecoxib体外对肝癌细胞有较强的细胞毒作用且以剂量、时间依赖方式抑制细胞增殖,并诱导凋亡,使细胞周期阻滞于G1／S期．COX-2与P-gp,Survivin表达密切相关．     

Mechanism of red blood cell aging: Relationship of cell density and cell age

The human red cell has a life span of 120 days. The mechanism that determines cell removal from the circulation with such precision remains unknown. Most studies of red cell aging have been based on analysis of cells of progressively increasing age separated by density. The relationship between red cell age and density has been recently challenged, and the hypothesis has been put forward that cell death is not the result of a progressive deterioration of essential cell constituents. This theory was based on preliminary observations in transient erythroblastopenia of childhood, which could not later be confirmed. When the relationship between cell aging and increasing density is critically reviewed, it appears to be based on firm experimental evidence, confirmed by in vivo demonstration of decreasing survival of cells of increasing age. Analysis of studies using buoyant density gradients reveals that this technique can easily distinguish the single exponential slope of decline for those cell components that change progressively throughout the red cell life span from the biphasic decline of those that decrease drastically at the reticulocyte-mature red cell transition. The view that the aging of the red cell and its removal from the circulation result from a progressive series of events during the 120 days of its life span appears to be the most consistent with the available data. Density separation, validated by much experimental evidence, remains a most useful technique for the study of the mechanism of aging of the red cell. © 1993 Wiley-Liss, Inc.     

细胞自噬与结肠癌Lovo细胞迁移和侵袭的相关性研究

目的探讨不同自噬状态对结直肠癌Lovo细胞迁移和侵袭能力的影响。 方法将Lovo细胞分为自噬增强组、正常细胞组和3-甲基嘌呤自噬抑制组。用激光共聚焦显微镜观察绿色荧光颗粒,用Q-PCR检测Beclin1 mRNA表达水平,透射电镜观察自噬溶酶体,Transwell实验评价Lovo细胞迁移与侵袭能力。 结果绿色荧光颗粒数以自噬增强组最多,其次为正常细胞组,而自噬抑制组最少。Beclin1 mRNA表达量自噬增强组为(1.23±0.12)个,正常细胞组为(1±0.13)个,自噬抑制组为(0.98±0.1)个。自噬增强组可见大量的自噬溶酶体,明显多于正常细胞组和自噬抑制组。迁移实验细胞计数：自噬增强组高于正常细胞组(138.0±16.7与90.7±12.9,P＝0.026)和自噬抑制组(138.0±16.7与92.7±26.7,P＝0.030)。侵袭实验细胞计数：自噬增强组高于正常细胞组(147.0±13.0与99.0±20.5,P＝0.028)和自噬抑制组(147.0±13.0与95.7±25.6,P＝0.021)。 结论结肠癌Lovo细胞自噬增强促进肿瘤细胞迁移和浸润,可能是局部浸润和远处转移的机制之一。     

胆红素对肝星状细胞-T6增殖及细胞周期的影响

[目的]观察胆红素对肝星状细胞(HSC)-T6增殖及细胞周期影响.[方法]将培养细胞分成正常组和胆红素不同浓度(10 μmol/L、30 umol/L、50 /μmol/L、70 μmol/L、100 μmol/L)干预组,采用MTT法观察胆红素对HSC-T6增殖的影响,流式细胞仪观察各组细胞周期的变化.[结果]①不同浓度胆红素对HSC-T6均有促进增殖作用,且呈一定的量效关系,与正常组比较差异有统计学意义(P＜0.05);②10 μmol/L、50 μmol/L、100 μmol/L浓度胆红素作用HSC-T6后,G0/G1期减少,S期增加,G2/M期增加,与正常组比较均P＜0.05.[结论]胆红素对HSC-T6均有促进增殖作用.     

Liver cell adenoma and liver cell adenomatosis

During the last three decades liver cell adenoma and liver cell adenomatosis have emerged as new clinical entities in hepato-logical practice due to the widespread use of oral contraceptives and increased imaging of the liver. On review of published series there is evidence that 10% of liver cell adenomas progress to hepatocellular carcinoma, diagnosis is best made by open or laparoscopic excision biopsy, and the preferred treatment modality is resection of the liver cell adenoma to prevent bleeding and malignant transformation. In liver cell adenomatosis, the association with oral contraceptive use is not as high as in solitary liver cell adenomas. The risk of malignant transformation is not increased compared with solitary liver cell adenomas. Treatment consists of close monitoring and imaging, resection of superficially located, large (>4 cm) or growing liver cell adenomas. Liver transplantation is the last resort in case of substantive concern about malignant transformation or for large, painful adenomas in liver cell adenomatosis after treatment attempts by liver resection.     

Red cell rheology in stomatocyte-echinocyte transformation: roles of cell geometry and cell shape

The influence of the shape of the red blood cell during stomatocyte- echinocyte transformation on its deformability was studied by microsieving through pores with diameters of 2.6, 4.5, and 6.9 micron. A stomatocytic transformation was produced by chlorpromazine (0.02, 0.1, and 0.5 mmol/L) and an echinocytic transformation by sodium salicylate (7.5, 30, and 120 mmol/L). For spherostomatocytes, an increase in filtration resistance through 2.6 and 4.5 micron pores was observed, whereas for spheroechinocytes, a decrease in filtration resistance through 2.6 micron pores was found. Larger pores (6.9 micron) were not sensitive to those shape changes. The changes in deformability can be explained by the fact that the surface area of (sphero)-stomatocytes decreased, whereas that of (sphero)-echinocytes increased; the cell volume remained essentially constant. Echinocytes produced by 24-hour adenosine triphosphate depletion differed from drug- induced echinocytes: they had an increased cell volume at constant surface area and consequently an increased filtration resistance through 2.6- and 4.5-micron filter pores. Shape changes with spicule formation are therefore not a homogeneous entity, and cell geometric factors (eg, surface area and volume) must be assessed with care. The viscosity of red cell suspensions at a hematocrit level of 45% was higher for drug-induced echinocytes than discocytes or stomatocytes at all shear rates tested. We conclude that the normal discocyte represents an optimum shape for the flow in vivo since a stomatocytic transformation could impair the passage through the microcirculation (decrease in cell filterability) and an echinocytic transformation could impair the flow in larger vessels (increase in blood viscosity).     

Establishment and characterization of a mantle cell lymphoma cell line

A mantle cell lymphoma (MCL) cell line (JeKo-1) was established from peripheral blood mononuclear cells of a patient with a large cell variant of MCL showing leukaemic conversion. JeKo-1 cells were Epstein-Barr virus negative and showed a B-cell phenotype with IgM⁺, IgD⁺, CD3^?, CD5⁺, CD10^?, CD19⁺, CD20⁺ and CD23^?; they overexpressed cyclin Dl, Bcl-2, c-Myc and Rb proteins. Bcl-1/J_H gene rearrangement was confirmed by polymerase chain reaction, although karyotypic analysis showed 40/41 chromosomes devoid of apparent t(11;14)(q13;q32) translocation. JeKo-1 cells were highly tumourigenic in SCID mice.     

Properties of the mantle cell and mantle cell lymphoma.

The major lymphoid inhabitant of the follicular mantle is the mantle cell, an immunologically na?ve B cell. It is the putative cell of origin of mantle cell lymphoma (MCL), the cells of which have similar morphologic, immunophenotypic, and molecular characteristics to the normal B lymphocytes of the mantle zone. In the past year a number of advances have been made in the biology of the normal mantle cell, its interactions with the other constituents of the follicular and mantle zone microenvironments, and the development of neoplasia in this cell population. In addition, new developments in diagnostic molecular pathology have been used to more readily identify cases of MCL. The authors summarize these new advances in the understanding of the biology of the mantle cell and newer ancillary techniques in the diagnosis of lymphomas arising from this cell type.     

Kinetics of dendritic cell chimerism and T cell chimerism in allogeneic hematopoietic stem cell recipients

Dendritic cells (DC) as potent antigen-presenting cells (APC) and T cells as effector cells play an essential role in the pathophysiology of both graft-versus-host (GvH) and graft-versus-leukemia (GvL) reactions after transplantation. Therefore, we determined the kinetics of DC and T-cell chimerism establishment after allogeneic hematopoietic cell transplantation (AHCT) in a group of 144 patients, using fluorescence-activated cell sorting (FACS) or magnetic cell sorting (MACS) followed by FISH or STR-PCR analysis for chimerism evaluation. In all, three cell lines investigated (CD3(+) T cells, CD11c(+) DC1 and CD123(+) DC2), we found a rapid and consistent establishment of complete donor chimerism (CDC) in over 70% of all patients during the first 6 weeks after AHCT. The rate of patients with CDC increased significantly over time within the first year after transplantation. A related donor (P=0.004) as well as an underlying lymphatic leukemia (P=0.03) were found to be significantly associated with development of MC in T cells. No significant correlation between DC or T cell chimerism and GvHD or relapse was detected. Our results thus demonstrate a fast and stable CDC in DC1, DC2 and T cells after AHCT that continuously increases over time in nearly all patients.     

Actin filament debranching regulates cell polarity during cell migration and asymmetric cell division

The formation of the branched actin networks is essential for cell polarity, but it remains unclear how the debranching activity of actin filaments contributes to this process. Here, we showed that an evolutionarily conserved coronin family protein, the Caenorhabditis elegans POD-1, debranched the Arp2/3-nucleated actin filaments in vitro. By fluorescence live imaging analysis of the endogenous POD-1 protein, we found that POD-1 colocalized with Arp2/3 at the leading edge of the migrating C. elegans neuroblasts. Conditional mutations of POD-1 in neuroblasts caused aberrant actin assembly, disrupted cell polarity, and impaired cell migration. In C. elegans one-cell−stage embryos, POD-1 and Arp2/3, moved together during cell polarity establishment, and inhibition of POD-1 blocked Arp2/3 motility and affected the polarized cortical flow, leading to symmetric segregation of cell fate determinants. Together, these results indicate that F-actin debranching organizes actin network and cell polarity in migrating neuroblasts and asymmetrically dividing embryos.

Cell polarity is a fundamental feature of virtually all eukaryotic cells and plays crucial roles in a wide range of cellular processes, including cell motility, asymmetric cell division, and cell signaling (1). The establishment of cell polarity involves the asymmetric assembly of distinct cellular components to perform specialized functions. The actin-related protein (Arp) 2/3 complex-dependent branched actin networks and the pushing force they produce provide the principal means for cells to remodel the plasma membrane during cellular polarization (2). For example, in the leading edge of a migrating cell, the local Arp2/3-nucleated actin polymerization powers asymmetric projections of the plasma membrane (3). During asymmetric cell division of the Caenorhabditis elegans zygote, an actomyosin flow is central to the transport of the polarity PAR proteins into defined subcellular domains (4).Actin filaments'' continuous assembly must be balanced by actin depolymerization to ensure a constant supply of actin monomers for new growth. The Arp2/3 complex potency in actin nucleation empowers this complex as an essential regulator to organize the actin cytoskeleton. While Arp2/3 by itself is biochemically inactive, interactions with nucleation-promoting factors (NPFs) such as the Wiskott Aldrich syndrome protein (WASP)/WASP family verproline-homologous (WASP/WAVE) family proteins shift the Arp2/3 complex from its open, inactive conformation to a closed, active conformation (5, 6). The conformationally activated Arp2/3 complex then binds to the side of preexisting actin filaments to nucleate a branch from the mother filament (7–12). Conversely, nucleation by Arp2/3 can be inhibited by several binding partners, including glia maturation factor (GMF), Gadkin, Arpin, and Coronin, whose activities replenish available pools of actin monomers and Arp2/3 complexes for sustained actin assembly (13–18).The coronin family proteins are conserved actin regulators (19). The phylogenetic analysis grouped coronin genes into three types (19, 20). The best-characterized coronin is the Type I coronin (e.g., Coronin 1B) that binds to actin filaments through the β-propeller structure and to the Arp2/3 complex via its N terminus. These interactions block the docking of Arp2/3 onto actin filaments or facilitate debranching the existing actin network (20). Coronin 1B simultaneously interacts with the Slingshot phosphatase to dephosphorylate and activate ADF/Cofilin proteins that sever actin filaments, thereby promoting the actin network disassembly (13). Despite significant progress on Type I coronin, the activity and function of other coronins remain unclear. In particular, Type III coronins, known as POD-1 in C. elegans and Drosophila or Coronin7 in Dictyostelium and humans, contain two tandem coronin repeats, making them distinct from other coronins (19–21). POD-1 was biochemically isolated from C. elegans oocytes (22), and its mutations disrupted the polarity and architecture in early C. elegans embryos and impaired midlife touch sensitivity of the nematode (21, 23). However, it remains unclear how the Type III coronin functions. The Drosophila homolog of POD-1 is required for correct axon guidance, and the purified Dpod-1 cross-links the actin and microtubule cytoskeletons (24), whereas the mammalian Coronin7 was implicated in the Golgi morphology and function (25, 26), demonstrating the functional divergence of this family of coronin. Here, we show that the C. elegans POD-1 debranches Arp2/3-nucleated actin filaments in vitro and that POD-1 regulates cell polarity by remodeling the actin cytoskeleton during cell migration and asymmetric cell division.     

Smooth muscle cell and endothelial cell growth factors

Blood vessels are composed basically of two cell types, vascular endothelial cells (ECs) and vascular smooth muscle cells (SMCs), whose proliferation in vivo is tightly regulated. A number of growth regulatory polypeptides have been identified that stimulate the proliferation of vascular cells. This article reviews briefly the structural properties and biologic activities of the best-characterized vascular cell growth factors. A fuller understanding of the properties of vascular cell growth modulators is an important element in delineating the proliferative events that are associated with vascular injury; with SMC hyperplasia such as occurs in restenosis following angioplasty, in atherosclerosis, and in hypertension; and with angiogenesis, both physiologic and pathologic.