Tissue microarray analysis of EGFR and erbB2 copy number changes in ovarian tumors

The objective of this study was to assess the implication of copy number changes of epidermal growth factor receptor (EGFR) and erbB2 genes in the etiology and progression of ovarian tumors. In our study, we used the highly reliable method of fluorescent in situ hybridization, applied on tissue microarray, containing 1006 ovarian tumors from different malignancy, histologic type and grade, and tumor stage, in order to analyze the correlations between gene copy number changes and tumor phenotype. We established copy number changes of erbB2 in 15.30% of malignant ovarian tumors-8.16% amplifications and 7.14% gains. The frequency of EGFR copy number changes was 10.67%-3.65% amplifications and 7.02% gains. EGFR gains occurred with approximately the same frequency in malignant (7.02%), low malignant potential (8.33%), and benign (7.19%) ovarian tumors. ErbB2 amplification was associated with clear cell type of ovarian cancer (P < 0.04). No amplification of EGFR and erbB2 genes was established in tumors with low malignant potency and in benign tumors. Regarding cancer phenotype, there was no statistically significant association between erbB2 copy number changes and histologic grade as well as tumor stage of ovarian cancer. EGFR gains are early events in ovarian tumorigenesis. Our results showed similar frequencies of EGFR gains in different grade tumors, while EGFR amplification increased from grades 1 to 2 to 3.     

人胎冠状动脉原位杂交c-myc和jun原癌基因表达

目的研究原癌基因c-myc和jun在人胎冠状动脉发育过程中的表达与平滑肌细胞增殖的关系.方法用原位杂交方法检测,胎龄分别为16周、22周(因治疗需要引产)的胎儿和意外死亡的足月胎儿冠状动脉前降支c-myc mRNA和jun mRNA的表达水平.杂交反应产物用图像分析仪(MIAS300)作定量分析.结果C-myc mRNA原位杂交反应产物与被测血管区域面积的百分比在16周、22周和足月胎儿分别是70、56和10;Jun mRNA的杂交信反应产物与被测血管区域面积的百分比在这三个时期分别是68、53和8.两个原癌基因在不同阶段的表达均具有显著性差异.结论本实验首次报道c-myc和jun在人胎冠状动脉发育过程中平滑肌的表达图型,c-myc和jun在胎儿冠状动脉平滑肌细胞增殖和内膜的形成过程中可能具有重要的调控作用.     

Quantitative expansion of structural genomic alterations in the spectrum of neuroendocrine lung carcinomas

The pathogenesis and interrelationships of neuroendocrine lung carcinomas are not well understood. Tissue macro-arrays prepared from surgical resection specimens from 35 patients with typical carcinoid (TC), six with atypical carcinoid (AC), 13 with large cell neuroendocrine carcinoma (LCNEC), and 15 with small cell lung carcinoma (SCLC) were investigated by fluorescence in situ hybridization (FISH) and immunohistochemistry. Hybridizations with locus-specific DNA probes demonstrated a high incidence of deletion for the tumour suppressor genes p53 and retinoblastoma (Rb), and for the oncogene cyclin D1, comparable in all carcinoma types. Similarly, an increase of DNA copy number for the Her-2/neu and c-myc oncogenes was noted in all neoplasms. A more detailed quantitative analysis of the results, however, demonstrated increasing numbers of cells harbouring these genomic alterations, from low-grade TC to highly malignant SCLC, with the exception of cyclin D1 deletion. Mutations of the p53 and Rb genes, as assayed by immunohistochemical studies, were observed at high incidence in high-grade carcinomas, compared with a low incidence in the low-grade carcinomas. Conversely, in all carcinoma types, neither membrane-bound Her-2/neu nor nuclear cyclin D1 was detected. It is concluded that structural genomic alterations are frequent in neuroendocrine lung carcinomas and that their occurrence may be underestimated by immunohistochemical studies alone. The quantitative expansion of the Rb, p53, c-myc, and Her-2/neu alterations towards high-grade carcinomas suggests common pathogenetic mechanisms in the spectrum of these neoplasms.     

Multiple genetic alterations in malignant metastatic insulinomas

Proto-oncogenes, growth factors/receptors, and tumour suppressor genes were analysed in malignant metastatic insulinomas. Normal pancreas showed only a moderate immunoreaction for c-myc proto-oncogene and a strong reaction for insulin. Benign insulinomas were slightly or moderately positive for transforming growth factor a (TGFα), weakly positive for epidermal growth factor receptor (EGF-R), and strongly positive for c-myc and insulin. In malignant insulinomas, besides a strong immunoreaction for c-myc and TGFα, activation of c-K-ras and overexpression of p53 protein were found. Insulin reaction was moderate or strong. Three out of six malignant insulinomas displayed a c-K-ras point mutation at codon 12. All mutations were guanine to cytosine transversion, resulting in amino acid substitution, glycine to arginine. Mutations were present in metastatic insulinomas only. Patients with mutated c-K-ras oncogene had overexpression of p53 protein as well as c-myc and TGFα overexpression. Our results support the view that malignant progression is a consequence of more than one genetic lesion and suggest that activation of myc, TGFα, and ras genesα plays a role in a multistep process of tumour progression, perhaps serving as an initiating event.     

Immunohistochemical demonstration of altered intracellular localization of the c-Myc oncogene product in human colorectal neoplasms

The distribution of the c-myc oncogene product p62 was examined by immunohistochemistry using the monoclonal antibody Mycl-9E10 in a series of 50 colorectal resections for carcinoma. The specimens were specially handled to ensure rapid fixation in formalin, and a significant improvement was shown in the quality and localization of staining compared with routinely handled specimens. Non-neoplastic mucosa showed the presence of nuclear staining of epithelial ceiis in 93 per cent of the samples, whilst all carcinomas showed cytoplasmic staining and infrequent nuclear staining. Adenomas showed an intermediate pattern, with significantly more frequent cytoplasmic distribution than non-neoplastic mucosa, but less than carcinomas. The results show that whilst fixation conditions are important in the immunolocalization of the C-myc protein product, there may be a consistent difference between non-neoplastic mucosa and carcinoma in the manner of association of p62 with the nucleus.     

子宫肿瘤表皮生长因子及其受体与C-erbB-2的表达

①目的 观察子宫肿瘤组织表皮生长因子（ＥＧＦ）及其受体（ＥＧＦＲ）和Ｃ－ｅｒｂＢ－２癌基因蛋白的表达及其意义。②方法 采用免疫组化方法检测了７３例子宫颈组织（１０例正常宫颈、１８例ＣＩＮ组织、４５例子宫颈癌组织）及７２例子宫内膜组织（增殖期内膜７例、分泌期内膜１０例、子宫肌腺病１０例、子宫内膜癌４５例）ＥＧＦ,ＥＧＦＲ及Ｃ－ｅｒｂＢ－２表达。③结果 子宫颈组织和子宫内膜组织中ＥＧＦ表达均为阴性。子     

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.     

Genetic manipulation of mammary epithelium by transplantation

Genes can be introduced into mammary epitheliumin vivo by the tissue reconstitution method. Primary cultures of mammary epithelial cells are prepared, a gene introduced using retrovirus vectors, and the cells transplanted into a mammary fat pad from which the normal epithelium has been removed. The cells reform an epithelium in which some cells express the introduced gene. The technique is reviewed and compared with the mammary-specific expression of genes in transgenic mice. To model the development of neoplasia, particularly the preneoplastic changes caused by a single oncogene alone, several oncogenes have been expressed this way—myc, Ha-ras, erbB, erbB2,Wnt-1, andhst/FGF-4. Each caused a different alteration to the growth pattern of the epithelium, such as altered branching, premature alveolus development, distorted duct structure, or altered hormone sensitivity. Insights into normal development have also been obtained by inappropriate expression of genes such asWnt-4.     

KAI1基因转染协同ATRA诱导对肺腺癌细胞株抑制作用的研究

目的 :探讨新抑癌基因KAI1与全反式维甲酸 (all trans retinoicacid ,ATRA)对肺腺癌A5 49细胞株抑制增殖和诱导分化的作用。方法 :用脂质体介导的基因转染方法 ,借助质粒表达载体 (PCMV NEO XhoI) ,将抑癌基因KAI1转入肺腺癌A5 49细胞中 ,经G418筛选 ,获得稳定表达的细胞克隆。用 10 6mol/LATRA作用于转染及未转染KAI1基因的肺腺癌A5 49细胞株 ,MTT法检测细胞体外增殖能力 ,流式细胞仪进行细胞周期和凋亡分析 ,间接免疫荧光染色结合流式细胞仪检测转染前后细胞CD82 蛋白的表达。免疫组化测定myc、基质金属蛋白酶 (MMP 1)的表达 ,放射免疫测定层连蛋白(LN)表达。结果 :ATRA处理KAI1基因转染的肺腺癌细胞CD82 表达降低 ,细胞增殖能力下降 ,凋亡增加 ,更多的细胞被阻止于G1/G0 期 ,myc、MMP 1及LN表达下降 ,比对照组及单纯转染组细胞差异有统计学意义 ,P <0 0 5。结论 :抑癌基因KAI1与ATRA对抑制肺腺癌A5 49细胞株的增殖浸润转移有协同作用。