Changes in retinoblastoma gene expression during cervical cancer progression

The role of tumour suppressor genes in the development of human cancers has been studied extensively. In viral carcinogenesis, the inactivation of suppressor proteins such as retinoblastoma (pRb) and p53, and cellular oncogenes overexpression, such as c-myc, has been the subject of a number of investigations. In uterine-cervix carcinomas, where high-risk human papillomavirus (HPV) plays an important role, pRb and p53 are inactivated by E7 and E6 viral oncoproteins, respectively. However, little is known about the in situ expression of some of these proteins in pre-malignant and malignant cervical tissues. On the other hand, it has also been demonstrated that c-myc is involved in cervical carcinogenesis, and that pRb participates in the control of c-myc gene expression. By using immunostaining techniques, we investigated pRb immunodetection pattern in normal tissues, squamous intraepithelial lesions (SILs) and invasive carcinomas from the uterine cervix. Our data show low pRb detection in both normal cervical tissue and invasive lesions, but a higher expression in SILs. C-Myc protein was observed in most of the cellular nuclei of the invasive lesions, while in SILs was low. These findings indicate a heterogeneous pRb immunostaining during the different stages of cervical carcinogenesis, and suggest that this staining pattern could be a common feature implicated in the pathogenesis of uterine-cervix carcinoma.     

Photoreceptor differentiation of retinoblastoma: An electron microscopic study of 29 retinoblastomas

Retinoblastomas exhibit a unique form of differentiation to produce cell elements similar to those seen in a photoreceptor cell. An ultrastructural study was performed on 29 cases of retinoblastoma to further clarify the cytologic characteristics of the tumor cells. The age of the retinoblastomas averaged 17.1 months and the tumor cells showing photo-receptor differentiation were demonstrated in 10 cases (35%). The findings were especially notable in retinoblastomas with Flexner-Wintersteiner rosette formation (seven cases, 28%). Similar photoreceptor differentiation was also evident in solid cell clusters without rosette formation (four cases, 14%). The presence of photoreceptor elements was assumed to be significantly frequent both in Flexner-Wintersteiner rosettes and in the solid cell clusters. The cell cytoplasm also showed proliferation of long mitochondria and microtubules, reflecting photoreceptor differentiation. The hereditary-type retinoblastoma showed more advanced cell differentiation than the non-hereditary type. Photoreceptor differentiated retinoblastoma showed rather indolent growth compared with the undifferentiated type, and the former can expect a curative treatment by operation. These observations provide additional findings of the biological nature of retinoblastomas.     

肺肿瘤癌基因与抑癌基因表达的研究

目的探讨癌基因与抑癌基因的表达与肺癌发生、发展的关系。方法对61例肺肿瘤标本,用免疫组化方法同时检测癌基因Bcl-2、抑癌基因视网膜母细胞瘤(Rb)、p53、p16。结果Rb与p16表达、p53与Bcl-2表达呈负相关(P<0．05),Rb与p53表达、p16与Bcl-2表达呈正相关(P<0．05)。结论肺癌的发生与发展是癌基因激活、抑癌基因失活及细胞凋亡调控基因异常等多基因损害的积累过程和协同作用使各细胞增殖调控途径失控,最终导致肺癌发生并使肺癌发展。     

视网膜母细胞瘤中Fas和bcl-2的表达及意义

目的　探讨Fas及bcl 2在视网膜母细胞瘤的表达及意义。方法　用免疫组织化学SP方法检测了 45例视网膜母细胞瘤及 12例正常视网膜组织中Fas及bcl 2蛋白的表达 ,并进行比较。结果　Fas在视网膜母细胞瘤组织及正常视网膜组织的表达分别为 0 .2 5 5± 0 .441,0 .0 83± 0 .2 89,两者比较差异无显著性 (P =0 .114 8) ,均呈低表达 ;bcl 2在视网膜母细胞瘤中的表达为2 .70 2± 1.0 82 ,与正常视网膜组织中 0 .16 7± 0 .389相比差异具非常显著性 (P <0 .0 0 0 1)。结论　Fas在视网膜母细胞瘤及正常视网膜中均呈低表达 ;而bcl 2在视网膜母细胞瘤中呈明显高表达 ,其可明显抑制凋亡的发生 ,与肿瘤的发展关系密切。     

P16和P53在视网膜母细胞瘤中的表达及其意义

目的研究Ｐ１６和Ｐ５３在视网膜母细胞瘤的表达。方法对３６例视网膜母细胞瘤标本采用免疫组织化学方法观察Ｐ１６和Ｐ５３表达水平。结果３６例标本中Ｐ１６和Ｐ５３阳性检测率分别是４７．２％和６６．６％,Ｐ１６和Ｐ５３阳性表达率在肿瘤的分化程度方面,差异有显著性（Ｐ＜０．０５）。结论Ｐ１６和Ｐ５３在视网膜母细胞瘤的产生和发展过程中起重要作用。     

EDWARD COTLIER AND ROBERT WEINREB, EDITORS Retinoblastoma in Transgenic Mice: Models of Hereditary Retinoblastoma

Retinoblastoma, the most common intraocular malignancy in childhood, has served as a paradigm for the study of genetic mechanisms of oncogenesis. The retinoblastoma susceptibility gene RB1 was the first tumor suppressor gene to be cloned, and genetic and molecular biologic studies of this tumor have greatly expanded the understanding of the mechanics of tumorigenesis. Human retinoblastoma has essentially no naturally occurring animal counterpart. The development of transgenic murine models of retinoblastoma have created an experimental tool for manipulation of a tumor gene system in vivo. These models have also enabled studies of new therapeutic modalities. This review outlines the development of the transgenic murine models of retinoblastoma, together with the genetic mechanisms of retinoblastoma origin. Current therapeutic innovations developed by means of the transgenic models are described.     

8—Br—cAMP对人视网膜母细胞瘤HXO—Rb44细胞癌基因的表达效应

目的 研究８－Ｂｒ－ｃＡＭＰ对培养的人视网膜母细胞瘤ＨＸＯ－Ｒｂ４４细胞癌基因表达的效应及其与该细胞生长的关系。方法 ｃ－ｆｏｓ ｍＲＮＡ,Ｎ－ｍｙｃ ｍＲＮＡ及ｐ２１ｒａｓ ｍＲＮＡ均以原位杂交ＲＮＡ斑点印迹技术检测,对繁殖细胞核抗原,ｖ－Ｆｏｓ,Ｎ－Ｍｙｃ和Ｐ＾２１ｒａｓ蛋白表达的免疫反应性则采用免疫组化及收白质斑点印迹技术检测。     

视网膜母细胞瘤36例临床病理分析

1966年 1月～ 2 0 0 1年 12月确诊为RB(retinoblastoma)的病例共 3 6例 ,其中 15例进行了免疫组织化学染色检查NSE、S 10 0、GFAP及PCNA等。光镜下 3 6例RB中未分化为主型 2 1例 ;高分化为主型 14例 ,自发消退型 1例。NSE、S 10 0、GFAP、PCNA在RB中的阳性表达依次为 9例 ( 60 % ) ;4例 ( 2 6 7% ) ,3例 ( 2 0 % ) ,15例 ( 10 0 % )。RB光镜下高分化型为主型 ,未分化型为主型 ,自发消退型中的菊形团 ,坏死和钙化等病理改变具有一定的诊断价值。免疫组化中NSE有助于鉴别诊断。RB肿瘤细胞有向神经元分化的能力 ,起源于神经外胚叶中的细胞 ,细胞增殖活性越高 ,其分化程度越低 ,预后越差     

紫杉醇诱导视网膜母细胞瘤细胞凋亡及对磷酸化Bcl-2的影响

目的：研究紫杉醇(Tax)抑制视网膜母细胞瘤(Rb)细胞生长并诱导其凋亡及磷酸化Bc-2在其中的作用。方法：应用^3H-胸腺嘧啶掺入分析法观察Tax对细胞生长的抑制作用，以DNA片段凝胶电泳分析细胞凋亡，用Western blot分析Tax对磷酸化Bcl-2的影响，用cDNA细胞转染法观察突变型Bcl-2阻断Tax的作用。结果：Tax可明显地抑制Y79细胞的生长，1μmoL／L Tax处理24小时，^3H-胸腺嘧啶掺入率下降达55．43％，Tax可诱导Y79细胞凋亡。在此过程中，Bcl-2被磷酸化。当Y79细胞被转染突变型Bcl-2后，Tax对Y79细胞的作用被阻断。结论：Tax可抑制Y79细胞生长并诱导其凋亡，磷酸化Bcl-2参与其过程。