正常的和转化的C3H小鼠胚胎成纤维细胞neu基因结构的初步研究

应用ＰＣＲ－ＳＳＣＰ技术并结合Ｓｏｕｔｈｅｒｎ印迹杂交从基因水平对正常和￣３Ｈ－ＴｄＲ恶性转化小鼠胚胎成纤维细胞ＮＣ３Ｈ１０和ＴＣ３Ｈ１０中ｎｅｕ基因进行研究。Ｓｏｕｔｈｅｒｎ印迹杂交结果表明恶性转化的ＴＣ３Ｈ１０细胞ｎｅｕ基因出现重排和扩增,ＳＳＣＰ分析未发现ＴＣ３Ｈ１０细胞ｎｅｕ基因跨膜区突变。上述结果说明ＴＣ３Ｈ１０细胞ｎｅｕ基因结构异常可能在跨膜区外,ｎｅｕ基因异常在￣３Ｈ－ＴｄＲ诱导的细胞恶性转化过程中可能有重要的作用,ＥＧＦ可促进ｎｅｕ基因表达增高,研究发现在ＥＧＦ持续作用下,ＮＣ３Ｈ１０细胞ｎｅｕ基因甲基化水平无显著变化,说明ＥＧＦ可能是通过其它途径调控ｎｅｕ基因表达增高的,排除了ＥＧＦ通过改变ｎｅｕ基因甲基化水平而调控ｎｅｕ基因表达的可能性。     

新的癌症治疗与诊断技术

一代全新的癌症诊疗手段初见端倪，将造福于千千万万的肿瘤患者。如果一名病人被诊断患有癌症，医生将采用新的诊断方法进行一系列检测，确定是癌基因过度表达还是发生了基因突变，其结果将指导治疗。其中新开发出的一种检测方法是检测ＨＥＲ－２／ｎｅｕ生长因子受体。在３０％～５０％的转移性乳腺癌患者中，ＨＥＲ－２／ｎｅｕ生长因子受体被ＨＥＲ－２／ｎｅｕ癌基因过度表达。ＨＥＲ－２／ｎｅｕ检测法可使专家们通过检测尿或血样中的ＨＥＲ－２／ｎｅｕ片段对病人治疗后和非侵润性肿瘤缓解后的病情进行监控。诊断和治疗缺陷性成视网膜…     

正常的和转化的C3H小鼠胚胎成纤维细胞neu基因结构的初步研究

应用ＰＣＲ－ＳＳＣＰ技术并结合Ｓｏｕｔｈｅｒｎ印迹杂交从基因水平对正常和＾３Ｈ－ＴｄＲ恶生转化小鼠胚胎成纤维细胞ＮＣ３Ｈ１０和ＴＣ３Ｈ１０中ｎｅｕ基因进行研究,Ｓｏｕｔｈｅｒｎ印迹杂交结果表明恶性转化的ＴＣ３Ｈ１０细胞的ｎｅｕ基因出现重排和扩增,ＳＳＣＰ分析未发现ＴＣ３Ｈ１０细胞ｎｅｕ基因跨膜区突变,上述结果说明ＴＣ３Ｈ１０细胞ｎｅｕ基因结构异常可能在跨膜区外,ｎｅｕ基因异常在＾３Ｈ－ＴｄＲ诱导的     

与肿瘤转移有关的基因的研究进展

与肿瘤转移有关的基因的研究进展姚旻,周信达（上海医科大学肝癌研究所,上海２０００３２）关键词癌基因,抑癌基因,肿瘤转移相关基因肿瘤转移过程复杂,包括①肿瘤细胞通过表面受体和细胞外基质发生特异性粘附;②肿瘤细胞本身或局部微生态系统（ｍｉｃｒｏｅｃｏｓｙ...     

人类第五染色体5q13.3带区一新基因的分子克隆初报

人类第五染色体５ｑ１３．３带区是毛发样白血病、ｒｅｆａｃｔｏｒｙ白血病、骨髓增生不良综合征、卵巢癌、肺癌等恶性肿瘤的共同畸变区域,表明该区域可能存在一个或多个同恶性肿瘤发生有关的基因（癌基因或抑癌基因）．克隆这些有关基因并进一步鉴定,对于阐明恶性肿瘤的发病机理,进而应用于基因治疗具有重要的理论和实践意义．本文报道位于该区域的一个新基因的ｃＤＮＡ克隆及在人体不同组织表达的初步结果．     

P73表达在人类肿瘤中的意义

原癌基因（proto-oncogene）的激活和/或抑癌基因（tumor suppressor gene）的缺失和灭活是恶性肿瘤发生、发展的分子生物学基础.P53基因是迄今为止发现的与人类肿瘤相关性最高的抑癌基因,其第一个被发现的家族成员P73基因作为候选的抑癌基因受到学者们的广泛关注.本文对P73基因在人类肿瘤中的表达及意义作一综述.     

肺癌发生过程分子生物学机制的研究进展

肺癌已成为人类癌症死亡的主要原因之一。综述近年来在肺癌发生发展过程中起重要作用且研究较为成熟的癌基因、抑癌基因及一些肺癌相关蛋白,它们包括细胞周期素D1(Cyclin D1)及抑癌基因p16、肺癌转移相关蛋白、谷胱甘肽-S-转移酶(GSTs)、癌基因Bcl-2、ras基因、恶性肿瘤特异性生长因子(TSGF)、绒毛膜促性腺激素(HCG)、粘蛋白、8-羟基-脱氧鸟苷(8-OH-dG)、具有磷酸酯酶活性的抑癌基因-PTEN、组织多肽特异性抗原(TPS),通过介绍这些生物大分子在肺癌组织中上调或下调机制,以期为肺癌的早期检测和治疗提供标志物。     

脆性组氨酸三联体（FHIT）基因

人类第３号染色体上的基因座在不同的肿瘤组织中出现高频率的杂合性丢失（ＬＯＨ），提示该部位可能是抑癌基因潜伏的位点。最近克隆的脆性组氨酸三联体基因（ＦＨＩＴ）可能是定位于染色体３ｐ１４．２的一个抑癌基因，该基因在肿瘤组织中广泛地缺失为研究肿瘤发生机制提供了新线索。     

基因转移与癌

本书为癌基因研究论文集。书中综述了癌基因研究的一些新的发现及其进展。分属几个方面介绍和论述了细胞致癌基因、癌基因在哺乳动物中的转移和表达。 一、细菌的转化作用:从基本理论和机理方面论述并阐明了嗜血杆菌转化中对DNA识别的顺序特异性和非序列特异性成分。     

转基因小鼠在肿瘤研究中的应用

将可能激发肿瘤的基因导入小鼠受精卵,已制备了许多具有癌症倾向的小鼠系。这些小鼠能使人在整体水平系统研究不同癌基因在细胞分化、增殖中的作用以及在肿瘤发生中癌基因间的协同作用。同时,这些小鼠具有对病毒和化学致癌物敏感的倾向,因而为潜在致癌原测试,治疗和预防肿瘤药物的筛选提供了很有价值的研究模型。 过去20年,用分子克隆和基因转移等手段,将癌基因导入特定细胞以研究癌基因在细胞转化过程中的作用机制,取得了可喜进展。     

v-rasH expression confers hormone-independent in vitro growth to LNCaP prostate carcinoma cells

The LNCaP human prostate cancer cell line is dependent on androgen for in vitro growth. To discover genes that may be responsible for progression of prostate cancer from hormone dependence to hormone independence, we transfected LNCaP cells with expression vectors that contained either the v-rasH or c-rasH gene under the control of the cadmium (Cd2+)-inducible human metallothionein-IIA promoter. Numerous derivative cell lines were isolated which manifested inducible expression of rasH p21 protein when the cells were treated with Cd2+. None of the cell lines transfected with c-rasH were found to have an altered growth phenotype. Several derivative cell lines expressing inducible v-rasH manifested hormone-independent growth in culture when treated with 10(-7) M Cd2+ . Cd2+ induction of v-rasH p21 was also shown to increase anchorage-independent colony formation of the v-rasH-expressing cell lines tested. Expression of a dominant mutated oncogene can change the hormone-dependent growth phenotype of prostate cancer cells.     

HER-2/neu基因高表达及靶向治疗

HER-2/neu癌基因在许多肿瘤,如乳腺癌、卵巢癌、非小细胞肺癌等肿瘤中高表达,在肿瘤的发生与发展中起重要作用,与肿瘤的转化、转移、复发、预后差、患者生存期缩短有关。HER-2/neu在乳腺癌过度表达率约为20%～30%,编码蛋白P185HER2属生长因子受体家族,抗P185HER2单克隆抗体(Herceptin)作为靶向药物已临床应用治疗HER2/neu高表达乳腺癌。     

Amplification of the neu (c-erbB-2) oncogene in human mammmary tumors is relatively frequent and is often accompanied by amplification of the linked c-erbA oncogene.

We investigated alterations in the structure and expression of oncogenes in mammary tumors and mammary tumor-derived cell lines. In 16 of 95 samples, we detected amplification of the human neu oncogene, also known as c-erB-2, accompanied by overexpression in the tumors from which intact RNA could be isolated. In 10 of these DNAs, the linked oncogene c-erbA was also amplified, whereas another gene on human chromosome 17, p53, was present in normal copy numbers. Overexpression of c-erbA could not be detected in the tumors analyzed. The relatively high frequency of neu amplification points to a functional role in human breast cancer. Coamplification of the c-erbA oncogene could contribute to this disease as well but is most likely fortuitous.     

Growth inhibition of breast cancer cell lines overexpressing Her2/neu by a novel internalized fully human Fab antibody fragment

The Her2/neu oncogene is overexpressed in various human cancers of epithelial origin and is associated with increased metastatic potential and poor prognosis. Blocking the Her2/neu signalling has been the focus of most therapeutic approaches. In this paper, the Her2/neu extracellular domain expressed in soluble form in yeast Pichia pastoris was used in order to isolate a fully human Fab fragment from a combinatorial Fab phage display library, derived from invaded lymph nodes of a breast cancer patient. The isolated fully human Fab63 binds specifically the native Her2/neu receptor and competes with Herceptin for binding to soluble Her2/neu receptor. In Her2/neu overexpressing cancer cells, Fab63 is rapidly internalized and has significant antiproliferative effects, where ligand-independent mechanisms dominate signal induction. Moreover, in the presence of the ligand heregulin, growth inhibition was also detected by Fab63. The human Fab63 is a non-immunogenic agent with unique properties that can be applied in diagnosis and cancer therapy, with great potential for further manipulation towards the generation of an effective anticancer molecule.     

The N-terminal domain of SV40 large T antigen represses the HER2/neu-mediated transformation and metastatic potential in breast cancers

HER2/neu is known to be overexpressed in approximately 40% of human breast and ovarian cancers and it is associated with increased metastasis and poor prognosis. We have shown previously that the N-terminal domain of simian virus 40 large T antigen (LT425) can act as a transforming suppressor of the HER2/neu oncogene in human ovarian cancer. In the present study, we demonstrate that LT425 can also repress the transforming properties of HER2/neu-overexpressing human breast cancer cells. In addition, the results of a chemotaxis assay and an in vitro chemoinvasion assay further suggest that LT425 can also suppress the metastatic potential of the HER2/neu-transformed breast cancer cells. Taken together, these data clearly suggest that the inhibition of the expression of p185 HER2/neu tyrosine kinase by LT425 is capable of suppressing the HER2/neu-mediated transformation and metastatic potential in breast cancers.     

A mechanism for hormone-independent prostate cancer through modulation of androgen receptor signaling by the HER-2/neu tyrosine kinase

Prostate cancer progresses from a hormone-sensitive, androgen-dependent stage to a hormone-refractory, androgen-independent tumor. The androgen receptor pathway functions in these androgen-independent tumors despite anti-androgen therapy. In our LAPC-4 prostate cancer model, androgen-independent sublines expressed higher levels of the HER-2/neu receptor tyrosine kinase than their androgen-dependent counterparts. Forced overexpression of HER-2/neu in androgen-dependent prostate cancer cells allowed ligand-independent growth. HER-2/neu activated the androgen receptor pathway in the absence of ligand and synergized with low levels of androgen to 'superactivate' the pathway. By modulating the response to low doses of androgen, a tyrosine kinase receptor can restore androgen receptor function to prostate cancer cells, a finding directly related to the clinical progression of prostate cancer.     

外源高表达PC-1蛋白N端43个氨基酸可加速人前列腺癌细胞系C4-2的生长

研究PC-1蛋白N端43个氨基酸表达对人前列腺癌细胞C4—2生长的影响。用DNA重组技术将含PC—1蛋白N端43个氨基酸的DNA序列正向克隆到真核表达载体pIRES2-EGFP中,采用脂质体法将重组质粒稳定转染进C4—2细胞中,RT—PCR分析外源序列的转录情况,固相ELISA法测定PC—1蛋白N端43个氨基酸的表达,MTT实验分析细胞的生长速度。结果获得了稳定转染PC—J基因N端43个氨基酸的前列腺癌细胞株,在该细胞株中外源PC—1蛋白N端43个氨基酸得到高表达,细胞生长速度较对照细胞加快了38％。结果表明外源PC—I基因N端43个氨基酸高表达可提高人前列腺癌细胞C4—2的生长速度,推论PC—J基因高表达可能在人前列腺癌的发展中起一定的促进作用。     

Her-2/neu oncogene expression in Puerto Rican females with breast cancer.

Her-2/neu belongs to the family of tyrosine kinase transmembrane proteins whose overexpression has been associated with a poor prognosis in patients with breast cancer. The product of this proto-oncogene is overexpressed in 25-30% of human breast cancer and is the target of selective immunotherapy. Concerned about the ethnic differences on the expression of this oncogene, we have evaluated 143 consecutive specimens of primary breast cancer diagnosed in San Pablo Hospital, Puerto Rico. The specimens were analyzed for Her-2/neu expression using immunohistochemistry assays (Hercept test). We have related the expression of hormone receptor status, percent cells in S phase, DNA ploidy, tumor size, nodal status and menopausal state with the Her2/neu expression. Out of 143 specimens, 28 overexpressed the Her-2/neu (19.6%). Of the Her/2 negative 30/114 (26%) were estrogen receptor negative as compared to 9/27 (33%) (p = 0.464). The degree of aneuploidy was abnormal in 25/104 (24%) in the Her-2/neu negative vs 11/27 (41%) p = 0.083. The percent cell in DNA synthesis was high in 16/77 (21%) in Her-2/neu negative vs 4/15 (27%) p = 0.613. The tumor size was greater than 2 cm in 35/106 (33%) in Her-2/neu negative vs 9/23 (39%) p = 0.575. In the progesterone specimens negative for Her2, 44/114 (39%) were Her2/neu negative vs 15/27 (56%) p = 0.108. No differences were seen regarding menopausal status, age and nuclear grading. A trend favoring abnormal aneuploidy in Her2/neu positive was seen. Nodal involvement was significantly associated with Her2/neu overexpression. (p = 0.037). Although the incidence of Her2 overexpression found in this database was somewhat lower than the one reported in the literature, this might also be due to the small cohort examined or to the technique utilized.     

Inhibition of breast and ovarian tumor growth through multiple signaling pathways by using retrovirus-mediated small interfering RNA against Her-2/neu gene expression

The Her-2/neu oncogene is overexpressed in approximately 30% of breast and ovarian cancer cases and often indicates a poor prognosis. Therapeutic agents against Her-2/neu have been intensively sought over the past decade. Here we show that small interfering RNA (siRNA) can silence the expression of Her-2/neu in models of human breast or ovarian cancer through retrovirus-mediated transfer of an siRNA against Her-2/neu. Cells infected with retrovirus expressing anti-Her-2/neu siRNA exhibit slower proliferation, increased apoptosis, increased G0/G1 arrest, and decreased tumor growth. Changes in cell cycle-associated factors included decreased levels of phosphatidylinositol 3-kinase, pAkt, and cyclin D1 and increased levels of p27 and phosphorylated retinoblastoma protein. Knockdown of Her-2/neu expression by siRNA is also associated with increased expression of the anti-angiogenic factor thrombospondin-1 and decreased expression of the pro-angiogenic vascular endothelial growth factor, suggesting that Her-2/neu stimulates tumor growth at least in part by regulating angiogenesis. siRNA-mediated gene silencing of Her-2/neu and increasing the expression of thrombospondin-1 may be a useful therapeutic strategy for Her-2/neu-over-expressing breast or ovarian cancer.