用流式细胞光度术(FCM)研究争光霉素对肿瘤及正常细胞周期的影响

用流式细胞光度术发现七种争光霉素组分(A₂+B₂混合品,A₂,A₂,A₅,A₆,A₅₀₃₃和B₂)都使中国仓鼠卵巢细胞(CHO)阻断在G₂期,而对G₁→S→G₂的进行无影响。这种G₂期阻断呈剂量依赖性。不同组分的G₂阻断效应不同,在40 μg/ml时,以A₄和A₅最强,其次为A₆,A₂,A₂+B₂混合物和B₂,而A₅₀₃₃无影响。用等毒性剂量,所有组分都使小鼠艾氏腹水癌产生多倍化细胞。由于争光霉素的G₂期阻断效应与抑瘤存在着平行关系,我们认为争光霉素的抑瘤作用与癌细胞被阻断在G₂期有关。     

博来霉素A6抗人体肝癌的实验研究

用克隆形成测定法检查博来霉素A₆对人肝癌、鼻咽癌和胃癌等细胞系的杀伤作用,发现对肝癌BEL-7402细胞有高度活性,半数杀伤浓度(IC₅₀)为6×10^-11mol/L。用流式细胞光度术研究表明,博来霉素A₆对肝癌BEL-7402细胞有G₂期阻断作用。在裸鼠可以耐受的剂量下,博来霉素A₆对移植性人肝癌的肿瘤生长有显著抑制作用,抑制率为75%。研究结果提示博来霉素A₆有可能用于肝癌化疗。     

环孢菌素A阻断人HL-60抗药性细胞于G1期而诱导敏感细胞凋亡

进一步研究了抗三尖杉酯碱的HL-60细胞(HR20)抗细胞凋亡的机制及该抗性和抗药性的关系。结果表明,环孢菌素A(CsA)20,10μg·ml^-1诱导HL-60细胞发生凋亡,而阻断HR20细胞于G₁期,就不能诱导细胞发生凋亡。低浓度的CsA明显增加柔红霉素在HR20细胞内的积聚,其逆转抗药性作用与阻断细胞周期运行无关。CsA10μg·ml^-1处理HR20细胞,可引起50kDa的蛋白质高度磷酸化。结果提示:环孢菌素A阻断抗三尖杉酯碱的HL-60细胞于G₁期,而诱导敏感的HL-60细胞发生凋亡,其阻断作用与抗药性无关。     

人参皂甙Rh2体外对小鼠黑色素瘤细胞的分化诱导作用

体外实验证明人参皂甙Rh₂在10μg·ml^-1的浓度下能明显抑制B₁₆细胞的生长,并呈浓度依赖性,其IC₅₀为4.1μg·ml^-1。Rh₂在10μg·ml^-1浓度下对B₁₆细胞有较强的分化诱导作用,表现为黑色素生成能力明显增加;形态向上皮样细胞分化;细胞呈网状结构;黑色素颗粒增多,生长变缓慢。细胞动力学研究结果表明,Rh₂可使B₁₆细胞阻断在G₁期。提示Rh₂对B₁₆细胞具有分化诱导作用。     

乙双吗啉(AT-1727)对L1210细胞动力学的影响

以显微分光光度法结合放射自显影两种方法,研究了乙双吗啉对L₁₂₁₀细胞动力学的影响。两种方法获得基本相似的结果。ip乙双吗啉50 mg/kg后,4 N细胞由未给药时的6.6%增加到23%,分裂细胞则明显减少,提示乙双吗啉可诱导G₂期细胞堆积。显微镜观察可见,堆积的G₂期细胞出现核肿胀,大量空泡,核破裂等现象,提示G₂期的阻断可能和G₂期细胞损伤有关。     

抗癌中药白毛藤对CHO细胞G2—PC染色体畸变的观察

本文应用细胞融合及PCC技术研究抗癌中药自毛藤对CHO细胞各时楣中PC染色体受损伤的效应。结果发现药物浓度在0.5—1.0克/毫升,处理45分钟后(37℃),G₂—PC染色体有较明显的损伤作用,表现为有各种染色体畸变;如裂隙、断裂、交换、双着丝点等。提示该药物能明显阻断G₂期细胞,在高剂量组1.0克/毫升时,尚可见到有少量的G₁-PC染色体有裂隙、断裂的损伤。在三种剂量组中,发现该药对M期细胞无明显的直接作用。并对药物剂量与各期细胞的作用作进一步的探讨。     

有机锡化合物抗肿瘤生物活性研究

有机锡(IV)化合物能明显地抑制大鼠脑组织中PKC活性和肿瘤细胞增殖，且两者之间存在着相关性。抗肿瘤活性的构效关系是：(1)有机基团R决定整个化合物的生物活性，Ph>Et>n-Bu；(2)卤素的电负性影响化合物活性的大小。抗肿瘤活性可能通过[snR₂]²⁺实现。并能部分地阻断HL-60细胞周期中的G_I期向S期的移行。[SnPh₂F₂]，[SnPh₂(CysOS)]H₂O和[SnPh₂Cl2·phen(CH₃)₂]对PKC的IC₅₀值分别为25，15和20 umol·L^-1，对HL-60细胞的IC₅₀值分别为0．5，4．0和0．3umol·L^-1。但它们无诱导分化HL-60和K562细胞的作用。     

二氯二羟二异丙胺合铂CHIP对小鼠艾氏腹水癌细胞动力学的影响

本文采用³H-TdR标记的放射自显影术,秋水仙碱阻断法和显微分光技术,研究了CHIP对小鼠艾氏腹水癌细胞动力学的影响。实验发现:CHIP(30 mg/kg)对呈指数生长和坪区生长的肿瘤细胞具有抑制增殖的效应,并可见对G₀细胞的损伤作用,对S期和M期细胞未见特异性杀伤。CHIP还能引起细胞周期进程的广泛延缓,尤其以G₁-S阻缓最为明显。上述结果表明CHIP为周期非特异性药物。     

紫杉醇诱导人乳腺癌MCF-7细胞周期阻断及凋亡的基因表达谱分析

目的研究紫杉醇诱导人MCF-7细胞周期阻断及凋亡的分子机制。方法用流式细胞仪分析紫杉醇对MCF-7细胞周期变化的影响，用自制的含9 984个已知基因和EST的高密度基因芯片检测MCF-7细胞在不同浓度紫杉醇作用下的基因表达变化。结果MCF-7细胞在100 nmol·L^-1紫杉醇作用24 h，流式细胞仪结果显示77.8%细胞阻断在G₂/M期和1.3%细胞发生凋亡；基因表达谱分析发现：在12.5 nmol·L^-1 (IC₅₀)及100 nmol·L^-1紫杉醇作用下，分别有27及77个基因差异表达。结论紫杉醇可诱导MCF-7细胞周期阻断在G₂/M期并引起部分细胞凋亡，该作用与药物浓度有关。基因表达谱分析显示部分差异表达基因参与细胞微管及骨架结构、细胞周期调控、以及DNA损伤修复和凋亡过程。     

黄芪抑制血管平滑肌细胞增殖及其作用机制

目的　观察黄芪(AS)对血管平滑肌细胞(VSMC)增殖的抑制作用,了解黄芪是否通过刺激VSMC产生一氧化氮(nitricoxide,NO) ,使细胞周期停滞于G₀/G₁期,从而抑制平滑肌细胞增殖。方法　[³H] 胸腺嘧啶核苷酸([³H] TdR)掺入测定VSMCDNA合成,流式细胞仪检测细胞周期情况,硝酸还原酶法测定细胞培养上清中NO水平。结果　黄芪以剂量依赖关系抑制血清诱导的VSMC[³H] 胸腺嘧啶核苷酸掺入,使G₀/G₁期细胞比例明显增多,S期细胞比例显著减少,黄芪刺激VSMC后,细胞培养上清中NO水平呈剂量依赖上升。结论　黄芪能抑制VSMC增殖,使细胞周期停滞于G₀/G₁期,这一过程可能与黄芪刺激VSMC产生NO有关     

氧化苦参碱与抗肿瘤药物相互作用对HNE-1、HNE-1(200)细胞周期的影响

目的了解天然有效成分氧化苦参碱(oxymatrine,Oxy)与常用抗肿瘤药物长春新碱(vincristine,VCR)、平阳霉素(bleomycin,BLM)、顺铂(cisplatin,DDP)、5-Fu相互作用后,对鼻咽癌HNE-1、HNE-1(200)细胞周期的影响。方法本研究以鼻咽癌HNE-1细胞株和由放射线诱导的鼻咽癌耐药细胞株HNE-1(200)为研究对象,分为不加任何药物的对照组、抗肿瘤药物与Oxy合用组以及维拉帕米(verapamil,VRP)与抗肿瘤药物合用组,采用流式细胞仪检测各组细胞周期的变化。结果(1)Oxy与抗肿瘤药物相互作用使实验细胞株发生明显的G_0/G_1期阻滞。(2)VRP与药物相互作用使实验细胞株也发生G_0/G_1期阻滞。(3)VRP与Oxy与药物相互作用结果相似,并且对两细胞株作用无显著差别。结论Oxy联合抗肿瘤药物后,可使鼻咽癌耐药细胞株和非耐药细胞株均产生G_1期阻滞,抑制细胞增殖,其作用与经典化疗增敏剂VRP相似,这为将Oxy作为化疗增敏剂提供了依据。     

应用离心淘洗技术研究VP对PYM细胞毒性的影响

应用最新细胞同步化方法——离心淘洗技术,同步分离体外培养小鼠红白血病细胞(MELC),研究钙拮抗剂异博定(Verapamil:VP)对国产抗癌药物平阳霉素(Pingyangmycin:PYM)细胞毒性的影响。无毒剂量的VP使PYM对未同步化的MELC细胞的毒性加强;同步化后,VP的加入使PYM对G2M期细胞的毒性增强,而对G1期和S期细胞的毒性无明显改变。结果提示,VP与PYM的作用可能有相同的周期特异性。     

Enhancement of bleomycin-induced DNA damage by exposing isolated DNA to high concentrations of the calcium antagonist verapamil

The calcium antagonist verapamil was found to enhance synergistically the DNA (desoxyribonucleic acid) strand breakage activity of the radiomimetic antitumor agent bleomycin in vitro. The induction of single and double strand breaks in isolated DNA was investigated by agarose gel electrophoresis. Three types of DNA (two plasmids and one native eukaryotic DNA) were used as target molecules. The effect of verapamil was concentration dependent (concentration range tested: 0.75-3.0 mmol/l). However, at those low concentrations, as they were used in cytotoxicity assays and cytogenetic experiments, no potentiating effect of verapamil on bleomycin action could be observed. The significance of these findings is discussed with respect to various hypothesis concerning the potentiation of tumor drug efficiency by verapamil and other calcium antagonists.     

Tallysomycin, a new antitumor antibiotic complex related to bleomycin. III. Antitumor activity of tallysomycins A and B.

The antitumor activity of tallysomycins A and B was determined in five experimental tumor systems in mice. Tallysomycins A and B were highly active against B16 melanoma, sarcoma 180 ascites tumor and Lewis lung carcinoma, and moderately active against P388 leukemia but were without effect on lymphoid leukemia L1210. The antitumor activity of tallysomycin A was 2 to 3 times that of tallysomycin B and 3 to 17 times that of bleomycin. Tallysomycin A was about 1.5 and 4 times more toxic for mice than tallysomycin B and bleomycin, respectively, in terms of subacute LD50 values.     

3-氨基苯甲酰胺增强平阳霉素的抗瘤作用

3 AB是聚(ADP-R)合成酶抑制剂,能在体外和体内协同地增加平阳霉素对S_(180)的抑制作用,而本身不具有抗瘤与细胞毒作用。这种加强作用与3 AB的剂量有关,剂量加强因子为4。在体内实验中加用3 AB后,平阳霉素对小鼠S_(180)的抑制率由原来的32.3%,41.4%,37.4%和66.0%分别增至60.1%,72.4%,68.3%和77.8%,我们还在体内探讨了量效关系及给药方式的影响。     

Increased toxicity of anthracycline antibiotics induced by calcium entry blockers in cultured cardiomyocytes

Calcium channel blocking drugs have been reported to reduce survival rate of laboratory animals treated with cardiotoxic antitumor anthracyclines. In order to elucidate the mechanisms of this drug interaction, cell toxicity of the anthracyclines, doxorubicin and daunorubicin, was evaluated in primary cultures of cardiac myocytes isolated from neonatal rats. Low concentrations of extracellular calcium ([Ca2+]0) and addition of calcium entry blockers (nifedipine or flunarizine) potentiated myocardial toxicity of anthracyclines as assessed by the release of lactate dehydrogenase from the cells. Accumulation of anthracyclines in the cardiomyocytes was increased by calcium entry blockers (nifedipine, flunarizine, and verapamil) and by low [Ca2+]0; efflux of [3H]daunorubicin from myocardial cells was inhibited by nifedipine. At a dose that exerts only modest calcium channel activity, R-verapamil failed to affect doxorubicin accumulation in cardiomyocytes, whereas the calcium channel activator, (+/-)-Bay K-8644, reduced the retention of anthracyclines; the calcium channel activity is thus required in order to increase the accumulation of anthracyclines in myocardial cells. Calcium channel blockers are also known to increase intracellular retention and toxicity of chemotherapeutic drugs in multidrug resistant tumor cells by inhibiting the efflux of cytotoxic agents from cells; however, the ability of the interacting drugs to inhibit the efflux of chemotherapeutic agents from tumor cells is not dependent on the calcium channel blocking activity. Therefore, the mechanism(s) by which calcium channel blocking drugs increase the accumulation of anthracyclines in resistant tumor cells and myocardial cells may be different. In accordance with previous investigations, the present in vitro study confirmed that anthracycline-induced cardiotoxicity may be potentiated by calcium channel blocking drugs. This indicates that, in the association of antineoplastic drugs with agents that reverse multidrug resistance, the potential exists for enhanced damage of normal cells and tissues; further studies are needed to evaluate the relevance of this adverse interaction.     

2,3-吲哚醌抗肿瘤作用研究

目的研究2,3-吲哚醌的抗肿瘤作用及机制。方法观察2,3-吲哚醌对小鼠肉瘤(S180)、小鼠肝癌(H22)、小鼠艾氏腹水瘤实体型(EC)和腹水型(EAC)的抗肿瘤作用;免疫组化法测定药物对S180肿瘤组织中PCNA、Bcl-2蛋白表达的影响;核染色法(Hoechst33258染色)和MTT法观察2,3-吲哚醌对人神经母瘤(SH-SY5Y)细胞体外促凋亡和抗增殖作用。结果2,3-吲哚醌对3种小鼠移植性肿瘤有抑制作用,对荷瘤鼠血液白细胞水平无影响;2,3-吲哚醌可抑制S180肿瘤组织中PCNA,Bcl-2蛋白表达;2,3-吲哚醌可促进人神经母瘤细胞凋亡并抑制其增殖。结论2,3-吲哚醌有抗肿瘤作用,其机制与抑制肿瘤细胞增殖,诱导肿瘤细胞凋亡有关。     

抗瘤酮类似物的抗肿瘤活性

本文报道15个抗瘤酮A_(10)衍生物对临床分离的六株肿瘤的抑制活性测定结果,比较了它们同临床常用抗癌药物对临床分离的食道癌89111的抑制活性,并对比测定了化合物4、7和9同抗瘤酮A_1。对小鼠S_(160)瘤株的抑制活性。     

白桦三萜类物质抗黑色素瘤B16、S180肉瘤作用及其机制的实验研究

目的　研究白桦三萜类物质 (triterpenesofbetulaplatyphyllasuk .TBP)抗黑色素瘤B16、S180肉瘤及其诱导细胞调亡作用和对细胞周期的影响。方法　建立小鼠体内荷黑色素瘤B16和腹水型S180肉瘤模型 ,测定TBP的抑瘤率和生命延长率。用形态学检测方法 (Giemsa染色法 )和流式细胞光度术检测TBP诱导的细胞调亡和对细胞周期的影响。结果　TBP具有明显的抗肿瘤作用 ,1 2 g·kg-1TBP对黑色素瘤B16的抑瘤率为 5 1 40 % ,对荷S180肉瘤小鼠生命延长率为 41 0 4%。可诱导B16和S180肿瘤发生细胞调亡 ,G0 /G1期细胞比例增加 ,S期细胞比例下降。结论　TBP可明显抑制黑色素瘤B16和S180肉瘤生长 ,其机制与诱导细胞调亡和阻断细胞生长于G0 /G1期有关。     

Potent antitumor actions of the new antibiotic boningmycin through induction of apoptosis and cellular senescence

Boningmycin, a new antibiotic of the bleomycin family, is isolated from the fermentation broth of Streptomyces verticillus var. pingyangensis n.sp. This study aimed to evaluate its antitumor actions and mechanism. The results showed that boningmycin exhibited potent inhibitory effects on several human solid tumor cells and that it was stronger than bleomycin. The administration of boningmycin inhibited the growth of human hepatoma HepG2 xenografts in nude mice, with more efficacy than that of bleomycin. Boningmycin led to an increase of the reactive oxygen species involving iron and caused G2/M phase accumulation in the HepG2 and human breast cancer MCF-7 cells. Two types of cell death, apoptosis and senescence, were detected after exposure to boningmycin. The accumulation of sub-G1 phase cells, an index of apoptosis, and the activation of caspase apoptotic pathways were detected after treatment with higher concentrations of boningmycin. Low concentrations of boningmycin led to a senescent phenotype with an increase in senescence-associated β-galactosidase activity and the time-dependent increase of p21, p27, and p53 expressions from 48 to120 h. Taken together, the results showed that boningmycin exhibits potent antitumor actions through the induction of apoptosis and cellular senescence.