Elimination of drug-resistant myeloma tumor cell lines by monoclonal anti-P-glycoprotein antibody and rabbit complement

The effectiveness of ex vivo chemotherapy with drugs, such as vincristine, etoposide, and Adriamycin (doxorubicin, Adria Labs, Columbus, OH) for elimination of residual tumor cells from human bone marrow grafts could be undermined by the presence of multidrug- resistant tumor cells in the bone marrow. Therefore, to supplement chemoseparation, we investigated whether MRK-16, a monoclonal antibody (MoAb) to the surface moiety of multidrug resistance-associated P- glycoprotein antigen, can eliminate drug-resistant tumor cells in the presence of rabbit complement (RC). Two doxorubicin (DOX)-resistant human myeloma tumor cell line, 8226/DOX40 (resistant to 4 x 10(-7) mol/L DOX) and 8226/DOX6 (6 x 10(-8) mol/L DOX) with high and low amounts of cell surface P-glycoprotein, respectively, and the drug- sensitive parent cell line 8226/S were used as tumor models in this study. Using the limiting dilution assay, we have shown that three cycles of treatment with 25 micrograms/mL of MRK-16 MoAb and a 1:4 final dilution of RC eliminated 2.90 +/- 0.10 logs of 8226/DOX40 cells and 1.94 +/- 0.18 logs of 8226/DOX6 cells. One and two cycles of treatment were less effective, eliminating 0.47 +/- 0.40 and 1.94 +/- 0.36 logs of 8226/DOX40 and 0.12 +/- 0.20 and 1.63 +/- 0.58 logs of 8226/DOX6 cells, respectively. The 8226/S cell growth was unaffected by one to three cycles of treatment. The cell kill was not impaired when the antibody plus complement treatment was carried out on a mixture of 8226/DOX40 or 8226/DOX6 cells with a ninefold excess of irradiated bone marrow mononuclear cells (MNCs). The three cycles of treatment with antibody plus complement did not adversely affect granulocyte- macrophage colony-forming unit (GM-CFU) survival in hematologically normal marrows (92.5% to 104% survival) or in myeloma patient marrows (85% to 100%). These results show that it is possible to eliminate drug- resistant myeloma tumor cell lines from the admixed human bone marrow by treatment with MRK-16 MoAb plus RC. This method could prove to be effective for elimination of other drug-resistant tumor cell lines including those of leukemia and solid tumors, and will be further useful for supplementing chemopurging, and immunopurging of bone marrow with other antitumor cell antibodies.     

POEM syndrome

This article summarizes the clinical, radiological and laboratory features of syndrome, which is known by the acronym "POEMS". POEMS syndrome is a rare multisystemic syndrome with plasma cell dyscrasia. POEMS is characterized by the combination of polyneuropathy, organomegaly, endocrinopathy, M protein and skin changes. Other signs are frequently observed in affected patients, such as peripheral edema, arteriopathy, nephropathy, thrombocytosis and osteosclerotic lesions. The plasma cell dyscrasia in POEMS syndrome differs from the dyscrasia found in multiple myeloma. It has been suggested that pleiotropic cytokines which act in synergy on immune, nervous, endocrine and vascular systems could play a pathogenic role in POEMS syndrome.     

国产阿克拉霉素A的体内外抗肿瘤作用

国产阿克拉霉素A(aclacinomycin;ACM-A)能明显抑制体外培养小鼠白血病P₃₈₈和人体胃癌SGC-7901细胞的生长。在0.01 μg/ml浓度时能抑制65.4%的克隆形成,ED₅₀为0.0085μg/ml。ACM-A对白血病小鼠有显著治疗作用,延长小鼠生命时间143%,并有半数小鼠获得治疗。对Ehrlich腹水癌和肉瘤-180也有较强的抑制作用,对肉瘤-180的作用与adriamycin相似。ACM-A主要抑制³H-TDR和。H-UR分别参人人体胃癌细胞的DNA和RNA;大剂量时对蛋白质合成也有影响。P₃₈₈细胞实验中证明ACM-A对DNA合成的抑制程度与adriamycin相似,低于daunomycin。     

维拉帕米对MDR1基因转染的Swiss－3T3细胞的化疗增敏作用

为进一步了解维拉帕米对抗药性逆转作用的待征，在人ＭＤＲ１基因转染的Ｓｗｉｓｓ－３Ｔ３多药抗药性细胞，观察了维拉帕米逆转幅度与阿霉素抗性水平的关系。各个转染细胞与母细胞相比，阿霉素毒性明显降低。非毒性浓度（３Ｕｍｏｌ·Ｌ－１）的维拉帕米对阿霉素毒性的增强作用，在转染细胞均高于母细胞，但逆转幅度与抗性水平成反比。Ｓｏｕｔｈｅｒｎ杂交显示，转染细胞基因组中有ＭＤＲ１ｃＤＮＡ整合。转染细胞的阿霉素蓄积障碍可被维拉帕米纠正。讨论了药物主动转运的饱和现象在维拉帕米增强效应中的作用，以及Ｐ－糖蛋白与药物相互作用的方式。     

维拉帕米对MDR1基因转染的Swiss-3T3细胞的化疗增敏作用

为进一步了解维拉帕米对抗药性逆转作用的特征,在人MDR1基因转染的Swiss-3T3多药抗药性细胞,观察了维拉帕米逆转幅度与阿霉素抗性水平的关系。各个转染细胞与母细胞相比,阿霉素毒性明显降低。非毒性浓度(3μmol·L^-1)的维拉帕米对阿霉素毒性的增强作用,在转染细胞均高于母细胞,但逆转幅度与抗性水平成反比。Southern杂交显示,转染细胞基因组中有MDR1 cDNA整合。转染细胞的阿霉素蓄积障碍可被维拉帕米纠正。讨论了药物主动转运的饱和现象在维拉帕米增强效应中的作用,以及P-糖蛋白与药物相互作用的方式。     

Stable overexpression of PML alters regulation of cell cycle progression in HeLa cells

Our previous studies demonstrated that PML is a growth suppressor that suppresses oncogenic transformation of NIH/3T3 cells and rat embryo fibroblasts. PML is a nuclear matrix-associated phosphoprotein whose expression is regulated during the cell cycle. Disruption of PML function by t(15;17) in acute promyelocytic leukemia (APL) plays a critical role in leukemogenesis. To further study the role of PML in the control of cell growth, we have stably overexpressed PML protein in the HeLa cell line. This overexpression of PML significantly reduced the growth rate of HeLa cells and suppressed anchorage-independent growth in soft agar. We consequently investigated several parameters correlated with cell growth and cell cycle progression. We found that, in comparison with the parental HeLa cells, HeLa/PML stable clones showed proportionally more cells in G1 phase, fewer cells in S phase and about the same number in G2/M phase. The HeLa/PML clones showed a significantly longer doubling time as a result of a lengthening of the G1 phase. No effect on apoptosis was found in HeLa cells overexpressing PML. This observation indicates that PML suppresses cell growth by increasing cell cycle duration as a result of G1 elongation. To further understand the mechanism of the effect of PML on HeLa cells, expression of cell cycle-related proteins in HeLa/PML and parental HeLa cells was analyzed. We found that Rb phosphorylation was significantly reduced in PML stable clones. Expression of cyclin E, Cdk2 and p27 proteins was also significantly reduced. These studies indicate that PML affects cell cycle progression by mediating expression of several key proteins that normally control cell cycle progression. These results further extend our current understanding of PML function in human cells and its important role in cell cycle regulation.      

Isoelectric focusing of human von Willebrand factor in urea-agarose gels

An analytical technique has been developed for the isoelectric focusing (IEF) of plasma von Willebrand factor (vWF) in agarose gels containing urea. Under these conditions, vWF freely enters the gel and focuses without artifact. The focused vWF is visualized by staining fixed gels with 125I-labeled affinity-purified heterologous antibody. Utilizing a pH gradient of 5.0-6.5, normal vWF in plasma or purified preparations focuses into at least three bands with apparent isoelectric points (pI) between pH 5.7 and 5.9. A reproducible difference in the IEF pattern of vWF has been established between normal plasmas and those of individuals with variant von Willebrand's disease (vWd) type IIA and type IIB. In type IIA, vWF has a distinctly lower pI than normal. This difference may be related to the presence of smaller vWF multimers in IIA plasma because forms of vWF of corresponding size contained in normal cryoprecipitate supernatant have a similar pI. Type IIB von Willebrand factor has a pI intermediate between normal and IIA. Neuraminidase treatment of plasma samples before IEF results in an increase in pI in normal, type IIA, and type IIB vWF. The data suggest that none of the 16 type IIA and 9 IIB plasmas studied here contain significantly decreased amounts of sialic acid.     

小鼠Leydig细胞中调控类固醇合成时EGF与TGF-β1的相互作用

目的 探讨在纯化的小鼠Leydig细胞的原代培养中,转化生长因子-β1(TGF-β1)和表皮生长因子(EGF)在调控类固醇合成中的相互作用.方法 纯化小鼠睾丸Leydig细胞,并将其分为四组,不加EGF或TGF-β1的空白对照组、仅加入EGF(10ng/ ml; 72h)的EGF组、仅加入TGF-β1(1ng/ml; 48h)的TGF-β1组和加入EGF与TGF-β1的EGF+ TGF-β1组.在不同条件下,通过特定的放射免疫(RIAs)法检测培养基中睾酮和脱氢表雄酮(DHEA)的表达水平. 结果 TGF-β1和EGF分别增强了人绒毛膜促性腺激素 (hCG)刺激睾酮合成的功能,二者的最大浓度效应在促性腺激素的激素作用中是叠加效应.它们的叠加效应来自一种复杂的相互作用,这一相互作用发生在胆固醇底物水平和3β-羟基类固醇脱氢酶/异构酶(3βHSDI)作用的水平. 结论 TGF-β1和EGF对于线粒体胆固醇底物活性的相互抑制效应,伴随着对3βHSDI活性的刺激增加效应,表明这两种生长因子对于促性腺素诱导的睾丸雄激素合成具有叠加效应.     

干扰电治疗仪改善糖尿病神经原性膀胱逼尿肌无力：与电针治疗比较

目的:观察干扰电治疗仪治疗糖尿病神经原性膀胱逼尿肌无力的疗效,并与电针治疗比较。方法:选择2006-01/10佛山市第一人民医院康复科、内分泌科住院的糖尿病神经原性膀胱患者60例。随机分成对照组30例和治疗组30例,所有患者对实验和治疗知情同意。治疗组用日本米拉多公司生产的SD-21V干扰电治疗仪进行治疗,每次治疗25min,1次/d,每周6次,共治疗20次。对照组采用汕头市医用设备厂公司生产的805-AⅡ型电针仪治疗。穴位取双侧三阴交、膀胱俞、次髎,使用疏密波,15Hz,电流强度为耐受量,留针30min,1次/d,每周6次,共治疗20次。治疗前后测定尿流动力学指标、日平均排尿次数及尿量情况。结果:60例患者均进入结果分析。①尿流动力学的变化:治疗组最大膀胱容量、最大尿道闭合压、最大尿流率均大于对照组(P<0.01￣0.001),残余尿少于对照组(P<0.001)。②日平均排尿次数及尿量情况:治疗组日平均排尿次数、日平均单次尿量、日单次最大排尿量均大于对照组(P<0.05￣0.001)。结论:两种方法治疗糖尿病神经原性膀胱逼尿肌无力均有显著作用,干扰电疗法效果更好。     

鸭乙肝模型氧化应激反应及金丝桃苷的干预

目的:观察鸭乙肝病毒感染所致稚鸭血清及肝脏氧化应激状态的改变及金丝桃苷的干预作用。方法:实验于2006-03/07在中国医学科学院生物技术研究所以及解放军第三○一医院老年医学研究所进行。①实验分组:44只1日龄北京稚鸭随机分为7组:正常组,模型组,金丝桃苷15,30,60mg/(kg·d)剂量组,拉米夫定50mg/(kg·d)组和恩替卡韦0.25mg/(kg·d)组。其中正常组5只,金丝桃苷15,30,60mg/(kg·d)剂量组各7只,其余各组6只。②实验干预:除正常组外,其余6组每只动物经胫静脉注射鸭乙肝病毒阳性血清0.2mL,第7天开始灌胃给药,2次/d,给药10d,正常组和模型组给予等量生理盐水。停药后第3天处死动物检测相关指标。③实验评估:黄嘌呤氧化酶法测定超氧化物歧化酶活性、非酶促反应法检测谷胱甘肽过氧化物酶活性,硫代巴比妥酸法检测丙二醛含量。结果:纳入稚鸭44只,在模型制备及后期干预中无动物死亡,全部纳入统计分析。与正常组相比,模型组肝匀浆超氧化物岐化酶活性、谷胱甘肽过氧化物酶活性及丙二醛含量显著降低(P<0.01,P<0.05),而血清谷胱甘肽过氧化物酶活力及丙二醛含量显著升高(P<0.01,P<0.05);与模型组相比,金丝桃苷治疗组肝匀浆超氧化物岐化酶、谷胱甘肽过氧化物酶活性及丙二醛含量显著升高(P<0.01,P<0.05),然而血清谷胱甘肽过氧化物酶活性及丙二醛含量显著降低(P<0.01,P<0.05)。结论:鸭乙肝病毒感染引起稚鸭肝脏氧化应激损伤,金丝桃苷可有效的逆转肝损伤。