横纹肌样瘤的起源研究——高变异率BHK-21细胞致裸鼠产生恶性横纹肌样瘤的实验研究

横纹肌样瘤（ＲＴ）的起源迄今仍是世界上悬而未决的重大难题。第一例ＲＴ发现于肾脏。但迄今发现的ＲＴ均难以复制成功。在纯化３代的肿瘤阴性对照猫肾和犬肾原代细胞皮下接种裸鼠的致癌／致瘤率为０％（０／３２）,肿瘤阳性对照Ｈｅｌａ细胞皮下接种裸鼠产生进行性生长恶性肿瘤的比率为１００％（４０／４０）的前提下,ＢＨＫ－２１细胞皮下接种裸鼠均产生进行性生长的恶性肿瘤（６５／６５）,其中染色体众数为４０±２（比率５８％～６８％）的ＫＡ株致ＲＴ比率为５２．３８％（１１／２１）,具有两个染色体众数４０±２（比率４１％～５３．５）和７２±２（比率３１％～３５％）的ＹＡ株致ＲＴ的比率为８３．３３％（１０／１２）,染色体众数为７３±３（比率４２％～５０％）的成瘤细胞体外再培养ＮＭ２８／ＹＡ株致ＲＴ的比率为７１．４３％（１５／２１）,染色体众数为４２（比率２８％～３０％）的Ｍ株致ＲＴ的比率为０％（０／１０）,致形态类似于分化比较好的平滑肌肉瘤的恶性肿瘤的比率为１００％（１０／１０）,可见ＢＨＫ－２１细胞不能用作病毒活疫苗培养基质,可替代Ｈｅｌａ细胞用作恶性肿瘤阳性对照细胞。高变异率ＢＨＫ－２１细胞株皮下接种无胸腺裸鼠大多产生恶性ＲＴ（２６／４２）,但要求完形活细胞接种量要大（２～９×１０７／鼠）,肿瘤产生迅速,生长快速,血管丰富,供血充分,接种细胞后１０～２０天或２～３周肿瘤长径×短径均值基本达到３０ｍｍ×２０ｍｍ标准。其它高变异率细胞系接种丧失免疫机能的无菌实验动物,如环境条件和生长状况达到上述标准,理当可能产生恶性ＲＴ。ＲＴ在模型动物体内的首次发现和成功复制,为弄清ＲＴ的起源问题提供了机会。可见,肾上皮是恶性ＲＴ的重要起源组织,本研究开辟了ＲＴ起源研究的新阶段。克隆出致ＲＴ的高变异率ＢＨＫ－２１细胞株,建立ＲＴ裸鼠模型,并应用于ＲＴ的临床诊断防治或进一步探索,都具有重大意义。     

恶性横纹肌样瘤(MRT)的起源研究取得突破——高变异率BHK-21细胞移植于裸鼠皮下多呈MRT细胞形态生长为阐明该瘤的起源问题提供了机会

弄清恶性横纹肌样瘤（ＭＲＴ）的组织细胞起源是进行诊断并攻克防治问题的基础。自１９７８年首例发现于肾脏以来,有关该肿瘤的报道逐年增多,但迄今发现的ＭＲＴ均难以复制成功,ＭＲＴ的起源仍是医学上悬而未决的重大难题。作者在纯化３代的肿瘤阴性的对照猫肾和犬肾原...     

草鱼垂体STH细胞组织化学和超微结构研究

本文分别对草鱼性成熟前、后垂体ＳＴＨ细胞进行了组织化学和超微结构研究。垂体ＳＴＨ细胞多位于中腺垂体中部和背部,为嗜酸性细胞,用ＰＭＢ（ＰＡＳ－ＭＢ）和ＡＰＧ（ＡＢ－ＰＡＳ－ＯＧ）两种组织化学方法染色,对橙黄Ｇ阳性,对ＰＡＳ、ＡＢ阴性;电镜下电子密度较高,内质网绕核呈环形,分泌颗粒多而小。     

鉴别无色素性恶性黑色素瘤方法的探讨

无色素及少色素性恶黑鉴别诊断时,（１）组织化学铁反应,褪色素和黑色素银染对证实瘤细胞中黑色素是有帮助的,但不能从无色素性恶黑中检出黑色素。因此对无黑色素恶黑的诊断和鉴别诊断帮助不大。网状纤维染色良性病均有增加,而恶黑几乎没有增加或仅极少增加。因此网状纤维染色有助于良恶性的鉴别。（２）免疫组化Ｓ－１００１８例恶黑及６例良性痣均显示阳性,这对无色素恶黑的诊断是有价值的,但对色素痣的恶变帮助不大。１６例恶黑中１４例色素性与１０例无色素性恶黑ＨＭＢ４５均显示阳性,证明两者有共同抗原,总阳性率８７．５％,６例良性痣均为阴性,证明无ＨＭＢ４５抗原。结果提示ＨＭＢ４５免疫组化检测不仅对无色素及少色素性恶黑的诊断与鉴别诊断实用性大,还可以用于对恶黑与良性痣、良性痣恶变的鉴别。（３）本组４例无色素性恶黑电镜下均找到前黑色素小体。因此在其他方法诊断困难时,应用电镜检查对确诊具有决定性作用。     

带有逆转录病毒的恶性T淋巴细胞株的建立

从一例患神经系统疾病病人的外周血淋巴细胞中建立了一株恶性Ｔ淋巴细胞株ＣＭ－１并研究了它的生物学特性。用过滤的ＣＭ－１细胞的培养上清,可命名多发性血管硬化症病人的淋巴细胞转化恶性Ｔ淋巴细胞,由此建立ＣＭ－２细胞株。用ＣＭ－１和ＣＭ－２细胞皮下接种裸鼠,都能使裸鼠产生弥漫性恶性淋巴瘤。电镜下见到了类似于Ｃ型逆转录病毒的颗粒,逆转酶活性检测阳性。血清学和基因检测表明ＣＭ－１和ＣＭ－２中不存在本室常用的其     

NGF—Tf偶联物对PD模型中黑质神经元的保护作用

中华眼镜蛇毒纯化的神经生长因子（ＮＧＦ）与的转铁蛋白（Ｔｆ）通过生物素－亲和素偶联,观察其对于１－甲基－４－苯基－１,２,３,６－四氢吡啶（ＭＰＴＰ）引发的小鼠帕金森病（ＰＤ）模型中黑质神经元的保护作用。电镜下对小鼠脑组织切片的观察表明：ＭＰＴＰ组元的髓鞘脱落,并出现大量空泡和线粒体峭变形;光镜下对ＨＥ染色的切片则观察到ＭＰＴＰ组神经元中再现空泡,Ｎｉｓｓｌ体溶解,胞核固缩,并有Ｌｅｗｙ小体形成,     

细胞外Mn^2＋对内向整流钾通道（IRK1）的阻断作用

目的和方法：采用双微电极电压钳（ＴＥＶ）法研究细胞外Ｍｎ＾２＋对非洲爪蟾卵母细胞表达的内向整流钾通道（ＩＲＫ１）的阻断作用。结果：细胞外Ｍｎ＾２＋浓度分别为１、１．２５、２．５、５、１０和２０ｍｍｏｌ／Ｌ,Ｋ＾＋浓度为９０ｍｍｏｌ／Ｌ,可见Ｍｎ＾２＋对ＩＲＫ１的瞬间电流（旋加电压后２ｍｓ）具有Ｍｎ＾２＋浓度依赖性和电压依赖性阻断作用;细胞外加Ｍｎ＾２＋浓度较高时强;细胞外Ｋ＾＋浓度为９０ｍｍｏｌ／     

骨巨细胞瘤M-CSF、IL-1和TNF-α免疫组织化学研究

本实验应用免疫组织化学方法,检测巨噬细胞相关抗原、巨噬细胞集落刺激因子（Ｍ┐ＣＳＦ）、白细胞介素┐１（ＩＬ┐１）和肿瘤坏死因子┐α（ＴＮＦ┐α）在骨巨细胞瘤（ＧＣＴ）中的表达,结果表明,在ＧＣＴ中,Ｍ┐ＣＳＦ主要由纤维母细胞样基质细胞（ＦＣ）分泌;巨噬细胞样基质细胞（ＨＣ）是单核┐巨噬细胞系早期的未成熟细胞,主要分泌ＩＬ┐１和ＴＮＦ┐α,少数多核巨细胞（ＭＧＣ）也可产生ＴＮＦ┐α。本文提示,ＧＣＴ中的三种主要细胞能分泌Ｍ┐ＣＳＦ、ＩＬ┐１和ＴＮＦ┐α细胞因子,通过自分泌或旁分泌作用相互影响,共同促进ＧＣＴ的发生、发展及其侵袭性的生物学行为     

非何杰金氏淋巴瘤在石蜡切片的免疫表型研究

用单克隆抗体ＬＣＡ,ＵＣＨＬ１,ＭＴ１,ＭＢ１,ＭＢ２,ＬＮ１和ＬＮ２对６５例非何杰金氏淋巴瘤常规福尔马林固定石蜡包埋组织切片作免疫表型研究。证实Ｂ细胞性淋巴瘤５０例（７７％）。Ｔ细胞性淋巴瘤１１例（１７％）（４例染色不良,未能分型）。根据国际工作分类,本组Ｔ细胞淋巴瘤所占比例分别是１１％,２７％和１３％。全部病例中ＬＣＡ阳性率９７％。Ｔ细胞抗体ＵＣＨＬ;阳性率（９１％）明显高于ＭＴ１（７３％）,且与Ｂ淋巴细胞无交叉反应。４种Ｂ细胞抗体阳性率分别为ＬＮ。（９６％）,ＭＢ２（９４％）,ＬＮ１（８６％）,ＭＢ１（８４％）。ＬＮ２和ＬＮ１对源于滤泡中心细胞淋巴瘤有更强的反应。研究结果表明上述单克隆抗体可有效用于非何杰金氏淋巴瘤石蜡切片的免疫组织化学标记,合理选用单克隆抗体有助于进行免疫学分型。     

地塞米松诱导红系细胞凋亡的观察(英文)

正常机体内,红细胞生成素（ＥＰＯ）诱导红系细胞分化,并阻止其凋亡,使其维持机体所需足够的数量。本文采用诱发贫血病毒（ＦＶＡ）诱导ＢＡＬＢ／ｃ小鼠脾细胞所形成的红细胞为实验系统,研究了外界因子？？地塞米松（Ｄｅｘ）对ＥＰＯ作用的影响。取６８周雌性ＢＡＬＢ／ｃ小鼠,尾部静脉注射含ＦＶＡ的小鼠血清。１５天后,断颈处死。取脾于ＩＭＤＭ中漂洗、剪碎、过滤、离心、制成单细胞悬液,在ＥＰＯ存在下,于平皿中培养至不同的时期后,进行不同浓度、不同时间的Ｄｅｘ处理。取细胞进行：（１）台盼蓝染色计数死细胞数;（２）观察ＤＮＡ电泳图谱;（３）电镜检察细胞学变化。Ｆｉｇ．１表明：随着Ｄｅｘ处理浓度和时间的增加,细胞死亡率也增加。Ｆｉｇ．２表明：１０－４浓度Ｄｅｘ处理,即可使早（１２ｈ）、中（２４ｈ）幼期红细胞凋亡,ＤＮＡ断裂成多聚核小体,产生明显ＤＮＡ梯形带。Ｆｉｇ．３表明：高浓度Ｄｅｘ可以使早幼期红细胞凋亡。电镜观察表明：与对照（Ｆｉｇ．４）比较,Ｄｅｘ处理后,细胞核固缩,染色质沿核膜内面周边凝聚,核周间隙扩张,胞质内出现空泡（Ｆｉｇ．５）;随后细胞破碎,出现大量凋亡小体（Ｆｉｇ．６）。Ｄｅｘ拮抗ＥＰＯ,诱导红系细胞凋亡的现象此     

Malignant rhabdoid tumor in the renal allograft of an adult transplant recipient: a unique case of a rare tumor

Background

Renal transplant recipients have increased risk for developing malignant diseases because of immunosuppression or donor-to-recipient transmission. Malignant rhabdoid tumor (MRT) is a rare, highly aggressive and lethal tumor primarily affecting the kidney of infants and young children. MRT has not been reported in the renal allograft of an adult recipient after kidney transplantation.

Case presentation

In this report, a 47-year-old woman who received a kidney transplantation from an infant donor and developed a mass in the transplanted kidney is presented. Pathological examinations revealed a malignant tumor with rhabdoid cells morphologically and the loss of INI1 expression immunohistochemically. The diagnosis of malignant rhabdoid tumor in the transplanted kidney was made. We confirmed that donor-to-recipient malignancy transmission was the cause of MRT in the transplanted kidney by fluorescence in situ hybridization (FISH) and short tandem repeat (STR) analysis.

Conclusion

To our knowledge, this is the first case of MRT in an adult renal allograft recipient. This report highlights the importance of the criteria for selection of donors to screen possible malignant tumors transmission.

     

海蜇胚胎发育和变态过程超微观察

采用扫描电镜、透射电镜和蛋白银染色等方法研究了海蜇胚胎发育和变态过程中细胞超微结构变化。结果显示: (1)海蜇自受精卵至原肠期阶段细胞均等分裂, 细胞间存在大量连接, 细胞形态相近, 未出现显著分化; (2)海蜇自早期浮浪游虫阶段, 其外胚层细胞开始出现空泡化, 至4触手螅状体阶段外胚层细胞空泡体积逐渐增大, 而内胚层细胞仅在4触手螅状体阶段才出现空泡化。伴随着外胚层细胞空泡化比例的增大, 杯状体和4触手螅状体阶段出现疑似凋亡小体结构; (3)刺细胞分化于早期浮浪游虫期的外胚层近中胶层区域, 而后逐渐向外转移, 至4触手螅状体阶段发育成熟并转移至表面; (4)纤毛形成于早期浮浪幼虫, 在杯状体阶段逐渐退化, 并于4触手螅状体阶段完全消失; (5)在海蜇早期发育各个阶段, 其内部均发现大量着色较深的卵黄体, 且在浮浪游虫阶段首次发现了海蜇外层细胞主动吞噬细菌现象, 表明海蜇早期发育营养来自内源性和外源性两部分。研究结果可为阐明刺胞动物早期发育模式提供依据。     

Microbeam radiation therapy alters vascular architecture and tumor oxygenation and is enhanced by a galectin-1 targeted anti-angiogenic peptide

In this study, we sought to determine the therapeutic potential of variably sized (50 μm or 500 μm wide, 14 mm tall) parallel microbeam radiation therapy (MRT) alone and in combination with a novel anti-angiogenic peptide, anginex, in mouse mammary carcinomas (4T1)--a moderately hypoxic and radioresistant tumor with propensity to metastasize. The fraction of total tumor volume that was directly irradiated was approximately 25% in each case, but the distance between segments irradiated by the planar microbeams (width of valley dose region) varied by an order of magnitude from 150-1500 μm corresponding to 200 μm and 2000 μm center-to-center inter-microbeam distances, respectively. We found that MRT administered in 50 μm beams at 150 Gy was most effective in delaying tumor growth. Furthermore, tumor growth delay induced by 50 μm beams at 150 Gy was virtually indistinguishable from the 500 μm beams at 150 Gy. Fifty-micrometer beams at the lower peak dose of 75 Gy induced growth delay intermediate between 150 Gy and untreated tumors, while 500 μm beams at 75 Gy were unable to alter tumor growth compared to untreated tumors. However, the addition of anginex treatment increased the relative tumor growth delay after 500 μm beams at 75 Gy most substantially out of the conditions tested. Anginex treatment of animals whose tumors received the 50 μm beams at 150 Gy also led to an improvement in growth delay from that induced by the comparable MRT alone. Immunohistochemical staining for CD31 (endothelial cells) and αSMA (smooth muscle pericyte-associated blood vessels as a measure of vessel normalization) indicated that vessel density was significantly decreased in all irradiated groups and pericyte staining was significantly increased in the irradiated groups on day 14 after irradiation. The addition of anginex treatment further decreased the mean vascular density in all combination treatment groups and further increased the amount of pericyte staining in these tumors. Finally, evidence of tumor hypoxia was found to decrease in tumors analyzed at 1-14 days after MRT in the groups receiving 150 Gy peak dose, but not 75 Gy peak dose. Our results suggest that tumor vascular damage induced by MRT at these potentially clinically acceptable peak entrance doses may provoke vascular normalization and may be exploited to improve tumor control using agents targeting angiogenesis.     

THE ORIGIN OF THE ELECTRICAL CHARGES OF COLLOIDAL PARTICLES AND OF LIVING TISSUES

1. When a solution of a salt of gelatin or crystalline egg albumin is separated by a collodion membrane from a watery solution (free from protein) a potential difference is set up across the membrane in which the protein is positively charged in the case of protein-acid salts and in which the protein is negatively charged in the case of metal proteinates. The turning point is the isoelectric point of the protein. 2. Measurements of the pH of the (inside) protein solution and of the outside watery solution show that when equilibrium is established the value pH inside minus pH outside is positive in the case of protein-acid salts and negative in the case of metal proteinates. This is to be expected when the P.D. is caused by the establishment of a Donnan equilibrium, since in that case the pH should be lower outside than inside in the case of a protein-acid salt and should be higher outside than inside in the case of a metal proteinate. 3. At the isoelectric point where the electrical charge is zero the value of pH inside minus pH outside becomes also zero. 4. It is shown that a P.D. is established between suspended particles of powdered gelatin and the surrounding watery solution and that the sign of charge of the particles is positive when they contain gelatin-acid salts, while it is negative when the powdered particles contain metal gelatinate. At the isoelectric point the charge is zero. 5. Measurements of the pH inside the powdered particles and of the pH in the outside watery solution show that when equilibrium is established the value pH inside minus pH outside is positive when the powdered particles contain a gelatin-acid salt, while the value pH inside minus pH outside is negative when the powdered particles contain Na gelatinate. At the isoelectric point the value pH inside minus pH outside is zero. 6. The addition of neutral salts depresses the electrical charge of the powdered particles of protein-acid salts. It is shown that the addition of salts to a suspension of powdered particles of gelatin chloride also diminishes the value of pH inside minus pH outside. 7. The agreement between the values 58 (pH inside minus pH outside) and the P. D. observed by the Compton electrometer is not only qualitative but quantitative. This proves that the difference in the concentration of acid (or alkali, as the case may be) in the two phases is the only cause for the observed P.D. 8. The Donnan theory demands that the P.D. of a gelatin chloride solution should be 1½ times as great as the P.D. of a gelatin sulfate solution of the same pH and the same concentration (1 per cent) of originally isoelectric gelatin. This is found to be correct and it is also shown that the values of pH inside minus pH outside for the two solutions possess the ratio of 3:2. 9. All these measurements prove that the electrical charges of suspended particles of protein are determined exclusively by the Donnan equilibrium.     

大鼠中缝背核和中央上核内5－HT能神经元生后发育的免疫细胞化学及图像分析研究

本实验采用免疫细胞化学方法,研究了大白鼠中缝背核及中央上核内５－ＨＴ能神经元的生后转折变化,并结合图像分析对中缝中央上核内５－ＨＴ能神经元的生后发育进行了定量研究。结果显示,在生后第１天,中缝背核和中央上核内５－ＨＴ阳性胞体密集排列,突起较短。从Ｐ１到Ｐ３０,中缝背核内,５－ＨＴ阳性胞体密度明显降低,外侧部５－ＨＴ阳性细胞突起的长度显著增加。中缝中央上核内,至Ｐ１０,５－ＨＴ阳性胞体仍密集排列,且胞体增大,至Ｐ３０,细胞排列变得疏松。从Ｐ９０到Ｐ９０,中缝背核和中央上核内阳性细胞的分布及形态无明显变化。统计学处理结果表明,中缝中央上核内５－ＨＴ能胞体数量从Ｐ１到Ｐ３０有显著性增加,从Ｐ３０到Ｐ９０有显著性减少。胞体面积及周长从Ｐ１至Ｐ３０逐渐增加,在Ｐ１０至Ｐ３０阶段增长最快。Ｐ１与Ｐ３０以及Ｐ１与Ｐ９０比较,胞体形状因子显著增加。从Ｐ１至Ｐ３０,中缝中央上核外侧散布的５－ＨＴ阳性细胞逐渐减少,至成年只能偶尔见到,且胞体变得不规则。     

LYSOSOME FUNCTION IN THE REGULATION OF THE SECRETORY PROCESS IN CELLS OF THE ANTERIOR PITUITARY GLAND

The nature and content of lytic bodies and the localization of acid phosphatase (AcPase) activity were investigated in mammotrophic hormone-producing cells (MT) from rat anterior pituitary glands. MT were examined from lactating rats in which secretion of MTH¹ was high and from postlactating rats in which MTH secretion was suppressed by removing the suckling young. MT from lactating animals contained abundant stacks of rough-surfaced ER, a large Golgi complex with many forming secretory granules, and a few lytic bodies, primarily multivesicular bodies and dense bodies. MT from postlactating animals, sacrificed at selected intervals up to 96 hr after separation from their suckling young, showed (a) progressive involution of the protein synthetic apparatus with sequestration of ER and ribosomes in autophagic vacuoles, and (b) incorporation of secretory granules into multivesicular and dense bodies. The content of mature granules typically was incorporated into dense bodies whereas that of immature granules found its way preferentially into multivesicular bodies. The secretory granules and cytoplasmic constituents segregated within lytic bodies were progressively degraded over a period of 24 to 72 hr to yield a common residual body, the vacuolated dense body. In MT from lactating animals, AcPase reaction product was found in lytic bodies, and in several other sites not usually considered to be lysosomal in nature, i.e., inner Golgi cisterna and associated vesicles, and around most of the immature, and some of the mature secretory granules. In MT from postlactating animals, AcPase was concentrated in lytic bodies; reaction product and incorporated secretory granules were frequently recognizable within the same multivesicular or dense body which could therefore be identified as "autolysosomes" connected with the digestion of endogenous materials. Several possible explanations for the occurrence of AcPase in nonlysosomal sites are discussed. From the findings it is concluded that, in secretory cells, lysosomes function in the regulation of the secretory process by providing a mechanism which takes care of overproduction of secretory products.     

Differential expression of miRNAs in rhabdomyosarcoma and malignant rhabdoid tumor

Alveolar rhabdomyosarcoma (RMA) and malignant rhabdoid tumor (MRT) have a frequent metastatic spread and a poor prognosis. Aberrant miRNA expression is often found in metastatic tumors. The aim of this study was to identify specific miRNA expression patterns in these tumors. We analyzed the expression of miRNAs in RMA and MRT in tissue samples and in the rhabdomyosarcoma (RMS) cell lines (Rh30 and RD). Selected target miRNAs were modulated with mimic or inhibitor oligonucleotides. Functional analysis was monitored by flow cytometry and migration assays. A set of 107 differentially expressed miRNAs showed tissue-specific clustering of RMA and MRT. Comparison with the Sarcoma microRNA Expression Database revealed RMA- and MRT-specific miRNAs. Metastatic invasion associated miRNA miR-9^? was overexpressed in RMA. miR-200c—inhibiting migration—was lower expressed in RMA than in MRT. Transient transfection of RMS cells with a miR-200c mimic and miR-9^* inhibitor did neither increase the expression of the known target E-cadherin nor decrease migration. Expression of E-cadherin could be induced in RD cells using decitabine, but demethylation did not influence cell migration. Despite a comparable high rate of metastatic invasion pediatric RMA and MRT show a different pattern of miRNA expression possibly allowing risk stratification.     

INI1 expression induces cell cycle arrest and markers of senescence in malignant rhabdoid tumor cells

The INI1 gene, which encodes a functionally uncharacterized protein component of the hSWI/SNF chromatin remodeling complex, is often mutated or deleted in malignant rhabdoid tumor (MRT). Two isoforms of INI1, that differ by the variable inclusion of nine amino acids, potentially are produced by differential RNA splicing. To determine the effect of the two INI1 isoforms on cell growth, INI1-devoid (MRT) and INI1-expressing cell lines were transfected separately with mammalian expression vectors or transduced with adenoviruses. Transfection of the short form of INI1 into either INI1-deficient or expressing cell lines resulted in complete suppression of cell growth in colony formation assays. The longer splice variant induced moderate to severe growth suppression of MRT cells, but had a far milder effect on non-MRT cells. Transduction of MRT cells with adenoviruses expressing either isoform of INI1 led to a dramatic change in morphology, growth suppression, and cell cycle arrest. Furthermore, senescence-associated proteins were up-regulated after transduction, while levels of proteins implicated in cell cycle progression were down-regulated. Adenoviral delivery of INI1 into a non-MRT cell line, however, had no demonstrable effect on any of these parameters. These results support the genetic evidence that INI1 is a tumor suppressor gene gone awry in MRT cells, and also suggest that delivery of the INI1 gene to MRT cells by adenoviruses may lead to a more effective treatment of this highly aggressive malignancy.     

FK506 confers chemosensitivity to anticancer drugs in glioblastoma multiforme cells by decreasing the expression of the multiple resistance-associated protein-1

Malignant rhabdoid tumor (MRT) is a rare and highly aggressive neoplasm of young children. MRT is characterized by inactivation of integrase interactor 1 (INI1). Cyclin-dependent kinase 4 (CDK4), which acts downstream of INI1, is required for the proliferation of MRT cells. Here we investigated the effects of PD 0332991 (PD), a potent inhibitor of CDK4, against five human MRT cell lines (MP-MRT-AN, KP-MRT-RY, G401, KP-MRT-NS, KP-MRT-YM). In all of the cell lines except KP-MRT-YM, PD inhibited cell proliferation >50%, (IC₅₀ values 0.01 to 0.6 μM) by WST-8 assay, and induced G1-phase cell cycle arrest, as shown by flow cytometry and BrdU incorporation assay. The sensitivity of the MRT cell lines to PD was inversely correlated with p16 expression (r = 0.951). KP-MRT-YM cells overexpress p16 and were resistant to the growth inhibitory effect of PD. Small interfering RNA against p16 significantly increased the sensitivity of KP-MRT-YM cells to PD (p < 0.05). These results suggest that p16 expression in MRT could be used to predict its sensitivity to PD. PD may be an attractive agent for patients with MRT whose tumors express low levels of p16.     

ELECTRON MICROSCOPY OF PLASMA-CELL TUMORS OF THE MOUSE : II. Tissue Cultures of the X5563 Tumor

The X5563 tumor has been grown in tissue culture. Cells similar to those of the original tumor migrated from the explant and attached to the glass walls of the culture vessels. Electron microscopy showed that large numbers of particles, similar in morphology to virus particles, were associated with these cells after 7 days of culture. The two principal types of particles found in the tumor in vivo appear to be present in vitro. Many more of these particles, however, were larger and showed a more complex structure. Whereas the particles were mainly localized inside endoplasmic reticulum or the Golgi zone in the tumors in vivo, in the tissue culture the majority of the particles were associated with the plasma membrane and were found outside of the cells. The relation of the particles to the granular body is discussed as well as a possible relation to the mammary tumor agent.