人脑原发性肺瘤癌基因的研究——Southern吸印杂交分析

用c-myc、Ha-ras、v-sis及v-erbB四种癌基因为分子探针,对8例人脑原发性肿瘤和两例正常人脑DNA进行Southern吸印杂交分析。结果显示:以c-myc基因为探针进行分子杂交时,所有被检测肿瘤和正常对照都可见一条相同的10.0kb(HindⅢ酶切)人c-myc基因区带。其中一例室管膜瘤和一例脑膜瘤还出现另一条异常的7.0kb(HindⅢ酶切)c-myc基因区带。斑点杂交结果表明,上述两例肿瘤中有c-myc基因的扩增(2—8倍),同时还具有erbB基因的扩增(8倍)。Ha-ras及v-sis基因杂交,未见异常区带。上述结果提示室管膜瘤和脑膜瘤的发生可能与c-myc基因的激活有关;c-myc基因的异常变化与erbB基因扩增同时出现,可能为癌基因之间的协同作用提供证据。     

人膀胱癌中某些癌基因的研究

本实验应用Northern和斑点印渍杂交技术探测了人膀胱癌细胞株中c-myc、c-fos、erbB等癌基因的表达,以及TPA对这些癌基因表达的调控,发现BIU-87细胞有这些癌基因的表达,并能被TPA所增强,同时也发现人膀胱癌组织有c-myc、c-fos、erbB、N-ras基因的高表达。提示蛋白激酶C的激活可以诱导某些癌基因的表达。多种癌基因的表达异常可能在膀胱癌中起重要作用。     

P53，Rb和c－myc基因在人脑原发性肿瘤中的转录表达

采用RNA斑点杂交分析,对21例人脑原发性胶质瘤和11例人脑膜瘤中p53,Rb和c-myc基因转录水平的表达进行研究.发现48.4%的肿瘤中p53基因表达减弱,21.9%的肿瘤中Rb基因表达减弱;71.9%的肿瘤中c-myc基因表达增强.在p53基因表达减弱的15例病例中有13例(80%)c-myc基因表达增强.结果表明,p53基因表达减弱和c-myc基因表达增强与人脑原发性肿瘤的发生有关.     

CWE纯系小鼠脑组织发育过程中细胞癌基因及其表达研究

 本文以Ha-ras.c-fos、c-myc、v-erbB、mos五种癌基因片段为分子探针,应用斑点杂交技术,对CWE纯系小鼠脑组织发育的四个时期(胚胎期、新生期、性成熟期、体成熟期)的RNA进行分子杂交分析。发现:在实验各期中这几种癌基因的表达有较明显的变化。Ha-ras、c-fos、c-myc基因的表达在胚胎期和新生期脑组织中较高;v-erbB基因的表达在性成熟期脑组织中较高;mos基因在实验各期均无表达。DNA斑点杂交结果:小鼠脑组织发育各期均未观察到癌基因扩增现象。Southern杂交结果:CWE小鼠发育的各期均显示:5.4kb、3.4kb、1.8kb、1.0kb四条c-fos基因区带;7.4kb、4.5kb、3.4kb三条c-myc基因区带。结果表明:不同细胞癌基因在小鼠胚胎发育和胚后发育中有不同的表达。     

人原发性肺癌癌基因表达研究

分子生物学的新近发展揭示某些癌基因与人类肿瘤的发生、发展、分化密切相关。目前认为,至少有两大类癌基因,即myc家族基因与ras家族基因在肺癌的病理发生中起重要作用。但是有关肺癌基因表达的研究,国内迄今尚未见报道。 本研究以myc家族基因(c-myc、L-myc及N-     

生物素标记的6种cDNA探针检测S180及其克隆细胞株mRNA的表达

目的检测S180及其克隆细胞株S1B11及S2D9mRNA的表达,对这些细胞株进行识别和质量控制.方法用生物素标记的6种cDNA探针,细胞玻片原位杂交的方法检测细胞中mRNA的表达.结果北京市肿瘤研究所(肿瘤所)保存的S180与生物素标记的P16、c-fos、c-myc及c-jun探针杂交阳性,克隆细胞株S1B11与c-fos及c-jun探针杂交阳性,克隆细胞株S2D9与c-fos、c-myc及c-jun探针杂交阳性.结论肿瘤所S180及其2株克隆细胞中mRNA的表达不同,c-myc基因的表达与否可以把S1B11及S2D9克隆细胞区别开;细胞株致瘤性与癌基因表达有关.     

人类乳腺癌中几种癌基因的状态与临床指征关系的初步探讨

本文报告了乳腺癌标本中N-ras、c-myc和neu癌基因异常改变,包括扩增和重排,并对这些结构改变与乳腺癌临床指征的关系作了初步的分析。本文的实验结果表明这些癌基因可能在人类乳腺癌的生物学行为和发病方面起着一定的作用。     

P53，Rb和c－myc基因在人脑原发性肿瘤中的转录表达

采用ＲＮＡ斑点杂交分析,对２１测人脑原发性胶质瘤和１１例人脑膜瘤中ｐ５３,Ｒｂ和ｃ－ｍｙｃ基因转录水平的表达进行研究,发现４８．４％的肿瘤中ｐ５３基因表达减弱,２１．９％的肿瘤中Ｒｂ基因表达减弱;７１．９％的肿瘤中ｃ－ｍｙｃ基因表达增强,在ｐ５３基因表达减弱的１５例病例中有１３例（８０％）ｃ－ｍｙｃ基因表达增强,结果表明,ｐ５３基因表达减弱和ｃ－ｍｙｃ基因表达增强与人脑原发性肿瘤的发生有关。     

EGFR和Ki-67在胶质瘤中表达的研究进展

胶质瘤是颅内常见的原发恶性肿瘤,而某些癌基因的激活、过表达或扩增、重排导致脑胶质瘤的形成。主要讨论脑胶质瘤的生物学特点,指出当前研究某些与肿瘤增殖活性及侵袭能力相关的基因改变、蛋白表达,推测其增殖和侵袭活动的具体过程,这是攻克脑胶质瘤的基础和关键。在众多与肿瘤相关的蛋白和基因中,选择了主要反映脑胶质瘤增殖活性和侵袭能力的相关基因——EGFR、Ki-67进行综述。从分子生物学水平评估脑胶质瘤细胞增殖和侵袭状态,在分析和判断胶质瘤的生长、分化程度,指导治疗方案的选择及预后的判断等方面有着重要的实用价值;但对于患者的预后,还需结合年龄、肿瘤位置、病理分级以及其他标记物等进行综合评价。     

基因丢失或失活在肿瘤发生中的作用研究进展

在癌变原理的研究中,分子肿瘤学领域取得了令人瞩目的成就,发现了与肿瘤发生密切相关的两类基因。第一类是所谓的癌基因(原癌基因),它们是细胞的正常基因,在演化中高度保守,在细胞正常生长和分化过程中有着重要的生理功能。但在外界致癌因素的作用下,通过点突变、DNA重排和基因扩增等方式使这些癌基因激活而导致肿瘤发生。在体外的试验中,用已激活的癌基因去转染特定实验动物细胞,可以使     

Amplification of the N-myc oncogene in an adenocarcinoma of the lung

c-myc oncogene is the most extensively studied member of the myc gene family, which now consists of three characterized members, namely the c-myc, N-myc, and L-myc genes. Deregulation owing to amplification and/or rearrangements of the c-myc gene have been described in a variety of human malignancies. Several neuroblastomas have amplifications of the N-myc genes. The c-myc, N-myc, or L-myc oncogenes are also found amplified in different cell lines from small cell carcinomas of the lung. In this study, we have examined the c-myc, N-myc, and c-erbB oncogenes in 34 clinical and autopsy tumor specimens representing various histopathological types of human lung cancer, including nine small cell lung cancers. A 30-fold amplification of the N-myc gene was found in a tumor histopathologically and histochemically verified as a typical adenocarcinoma. No amplifications of the c-myc or c-erbB oncogenes were seen in any of the tumors. In the DNA of one small cell carcinoma, an extra c-myc and N-myc cross-hybridizing restriction fragment was observed, possibly owing to an amplification of a yet uncharacterized myc-related gene.     

Cellular oncogene expression in human tumors transplantable to athymic mice

Expression of 3 cellular oncogenes among 7 ones under investigation is identified in the majority of 20 strains of human tumors, passaged in nude mice without significant specificity as far as the type of the tumor is concerned. The levels of the expression of these 3 oncogenes (c-myc, c-fos, c-ras) were higher than the ones in primary human tumors except for the human melanoma Mel-2 strain, where the expression of c-myb oncogene was identified. All the rest oncogenes (c-mos, B-lym, c-sis, c-myb) showed no expression in human tumors of the examined strains.     

Oncogene alterations in primary,recurrent, and metastatic human bone tumors

We investigated the structure and the expression of various oncogenes in three of the most common human bone tumors—osteosarcoma (36 samples from 34 patients), giant cell tumor (10 patients), and chondrosarcoma (18 patients)—in an attempt to identify the genetic alterations associated with these malignancies. Alterations of RB and p53 were detected only in osteosarcomas. Alterations of c-myc, N-myc, and c-fos were detected in osteosarcomas and giant cell tumors. Ras alterations (H-ras, Ki-ras, N-ras) were rare. Chondrosarcomas did not contain any detectable genetic alterations. Our results suggest that alterations of c-myc, N-myc, and c-fos oncogenes occur in osteosarcomas, in addition to those previously described for the tumor suppressor genes RB and p53. Moreover, statistical analyses indicate that c-fos alterations occur more frequently in osteosarcoma patients with recurrent or metastatic disease. © 1996 Wiley-Liss, Inc.     

Induction of clonal monocyte-macrophage tumors in vivo by a mouse c-myc retrovirus: rearrangement of the CSF-1 gene as a secondary transforming event.

A mouse retrovirus containing the c-myc oncogene was found to induce tumors of mononuclear phagocytic cells in vivo. All tumors expressed the c-myc retroviral gene but not the endogenous c-myc gene (with one exception), and virtually all tumors were clonal with a unique proviral integration. This observation, coupled with a lag time in tumor formation, suggests that a second event, in addition to c-myc proviral integration, is necessary for the generation of neoplastic cells in vivo. All of the tumor cells expressed high levels of mRNA for both the putative colony-stimulating factor 1 (CSF-1) receptor (c-fms proto-oncogene product), as well as the c-fos proto-oncogene. Although all of the tumor cells proliferated in culture without the addition of exogenous CSF-1, which is required for the proliferation of primary macrophages partially transformed by the same c-myc retrovirus, several phenotypes were observed with respect to the expression of CSF-1 and granulocyte-macrophage CSF and to their growth factor responsiveness. The proliferation of one tumor, which secreted high levels of CSF-1, was blocked by specific anti-CSF-1 serum. This tumor was found to express altered CSF-1 mRNA and to have a DNA rearrangement at the CSF-1 locus. In this particular case, the data indicate that a CSF-1 gene rearrangement was the secondary event in development of the tumor. The pleiotropy of phenotypes among the other tumors indicated that there are a variety of other mechanisms for such secondary events which can be investigated with this system.     

Activation of c-myc and c-K-ras oncogenes in primary rat tumors induced by ionizing radiation.

An activated K-ras oncogene was detected by transfection in NIH 3T3 cells and by Southern blot analysis in 6 of 12 rat skin tumors induced by ionizing radiation. The DNA from 10 of the 12 tumors also showed c-myc gene amplification and restriction polymorphisms. Evidence for tissue specificity was observed in patterns of oncogene activation, with each of three clear cell carcinomas exhibiting activation of both c-myc and K-ras oncogenes.