基因扩增在肺癌中的研究进展

原癌基因的激活是包括肺癌在内的众多恶性肿瘤的重要特征,而原癌基因发生扩增被认为在原癌基因激活过程中起着重要作用.随着分子遗传学技术的发展,人们在实体瘤中发现越来越多的原癌基因存在着扩增现象,因此了解基因扩增可以为肿瘤早期诊断或治疗提供新的有效的靶点.本文综述了目前肺癌中基因扩增的研究进展.     

血液检测在结直肠癌诊断中的应用

利用病人血清作为检测样本 ,测定血液DNA水平及一系列相关基因及其表达产物的改变 ,可进行结直肠癌易感人群的筛选 ,肿瘤的早期诊断 ,转移及预后判断等 ,为结直肠癌的防治提供了较为有效的信息。     

基因扩增在肺癌中的研究进展

原癌基因的激活是包括肺癌在内的众多恶性肿瘤的重要特征,而原癌基因发生扩增被认为在原癌基因激活过程中起着重要作用.随着分子遗传学技术的发展,人们在实体瘤中发现越来越多的原癌基因存在着扩增现象,因此了解基因扩增可以为肿瘤早期诊断或治疗提供新的有效的靶点.本文综述了目前肺癌中基因扩增的研究进展.     

长链非编码RNA与结直肠癌

长链非编码RNA(lncRNA)是一类长度大于200 nt的非蛋白编码RNA分子,能同时与DNA、RNA和蛋白质分子相互作用,通过转录和转录后调控等多种作用机制在结直肠癌中发挥促癌或抑癌的双重作用。lncRNA表达异常或突变在结直肠癌的发生、发展、侵袭和转移过程中扮演着重要角色,且与患者预后密切相关。lncRNA有望为成为结直肠癌新的诊断和治疗靶点。     

中国人家族性结直肠癌错配修复基因大片段变异分析

目的分析中国人家庭性结直肠癌错配修复基因大片段变异的特点。方法 采用多重连接探针扩增技术，分析32例具有家庭史结直肠癌、20例散发性结直肠癌患者错配修复基因MSH2的16个外显子、MLH1的19个外显子及7个其它基因外显子的拷贝数。研究工作包括：（1）双盲法分析阴性和阳性对照样本，完成方法学可靠性检验；（2）分析结直肠癌患者外周血细胞DNA，筛查MSH2和MLH1基因大片段变异。结果 多重连接探针扩增技术分析系统稳定检出阳性对照样本的DNA大片段缺失；在3/32（9.4%）具有家庭聚集性结直肠癌患者中检出遗传性MSH2基因DNA大片段缺失。而在20例散发性结直肠癌患者未检出这类突变。结论 中国人家族性结直肠癌患者中错配修复基因的大片段变异是频发事件，对此类患者的遗传检测应包含错配修复基因大片段变异的筛查。     

基因扩增在肺癌中的研究进展

原癌基因的激活是包括肺癌在内的众多恶性肿瘤的重要特征,而原癌基因发生扩增被认为在原癌基因激活过程中起着重要作用.随着分子遗传学技术的发展,人们在实体瘤中发现越来越多的原癌基因存在着扩增现象,因此了解基因扩增可以为肿瘤早期诊断或治疗提供新的有效的靶点.本文综述了目前肺癌中基因扩增的研究进展.     

长链非编码RNA在结直肠癌诊断及预后中的研究进展

早期诊断和预后标志物的缺乏是导致结直肠癌(colorectal cancer,CRC)患者生存率低的主要原因.长链非编码RNA(long non-coding RNA,lncRNA)由于在CRC发生发展中发挥重要的作用,并且能在外周血中稳定存在,而被认为是具有潜在临床应用价值的生物标志物.     

Wnt基因与结直肠癌的发生

Wnt信号转导途径能够传递生长刺激信号 ,促进细胞的增殖和组织的生长发育。其过度的转导和异常的活化 ,可改变干细胞的微环境 ,维持、扩增干细胞分隔空间 ,引起干细胞数目的增加 ,最终导致恶性肿瘤 ,尤其是结直肠癌的发生。因此 ,对Wnt途径的进一步研究将为探索结直肠癌的发病机制以及寻找有效的诊治手段提供新的视角     

长链非编码RNA Linc00467在结直肠癌中的表达及影响

目的探讨长链非编码RNA Linc00467在结直肠癌中的表达和意义。方法实时荧光定量PCR检测Linc00467在结直肠癌组织和结肠癌细胞系中的表达水平。通过Transwell迁移实验、MTS实验和克隆形成实验检测Linc00467对结肠癌细胞迁移、增殖等行为的影响。统计纳入的67例患者的临床病理资料,分析Linc00467的表达水平和患者临床病理学特征之间的关系。结果 Linc00467在结直肠癌组织和细胞系中高表达。敲低Linc00467可以抑制结肠癌细胞的迁移和增殖。Linc00467的表达丰度与结直肠癌患者的临床病理特征之间无显著相关性。结论 Linc00467在结直肠癌中高表达,可以促进结肠癌的迁移和增殖。     

Tricho-rhino-phalangeal syndrome type I (TRP I) due to an apparently balanced translocation involving 8q24

Tricho-rhino-phalangeal (TRP) syndromes type I and II are caused by a defective gene located on chromosome 8q24.1. We report a family with 2 sibs affected with TRP type I in combination with an apparently balanced chromosome (8;18) translocation involving 8q24.11. It is very likely that the 8q24 translocation breakpoint is physically linked to the TRP gene(s), thereby facilitating future efforts to clone the TRP gene(s). © 1993 Wiley-Liss, Inc.     

A 15q24 microduplication, reciprocal to the recently described 15q24 microdeletion, in a boy sharing clinical features with 15q24 microdeletion syndrome patients

A 15q24 microduplication, reciprocal to the minimal critical region for the recently described 15q24 microdeletion syndrome, was found in a 2-year-old boy by 244k Agilent oligoarray CGH analysis. The boy had global developmental delay and dysmorphic facial features, digital and genital abnormalities. The duplication was inherited from a healthy father, but was considered clinically significant, as the patient shared clinical features with 15q24 microdeletion syndrome patients. To our knowledge this is the first report of a patient with a 15q24 microduplication.     

Interstitial duplication 8q22-q24: Report of a case proven by FISH with mapped cosmid probes

We report on a 6-month-old malformed female infant with a de novo interstitial duplication of an 8q22-q24 segment. She had an excess dark-band on the 8q distal region by GTG-banded chromosome analysis, which was likely to be 8q23. We performed FISH analysis using cosmid probes mapped to 8q23 and proved that the patient had an 8q duplication including the 8q23 region. © 1996 Wiley-Liss, Inc.     

Lower frequency of allele loss on chromosome 18q in human breast cancer than in colorectal tumors

Inactivation of tumor suppressor genes is thought to be a critical step in tumorigenesis. TheDCC (deleted in colorectal carcinoma) gene, located on the long arm of chromosome 18, has been shown to be frequently deleted in colorectal tumors. To investigate the involvement of allelic deletions on chromosome 18q in breast cancer tumorigenesis we analyzed 28 primary breast tumors and 28 colorectal, tumors (24 carcinomas, 4 adenomas) with four different polymorphic DNA markers detecting RFLPs on chromosome 18q. In breast cancer we found loss of heterozygosity (LOH) in 4 of 27 (15%) informative cases whereas 15 of 25 (60%) colorectal tumors showed allelic deletions. In all cases of allelic loss theDCC locus or its proximal vicinity (locus SSAV1) were involved. LOH on chromosome 18q occurs both in breast and colorectal cancer, yet the frequency of these deletions in breast tumors is lower than in colorectal tumors. Moreover, in breast cancer these mutations were only detected in large and undifferentiated tumors.Abbreviations LOH Loss of heterozygosity     

13q deletion is linked to an adverse phenotype and poor prognosis in prostate cancer

Deletions of chromosome arm 13q belong to the most frequent molecular alterations in prostate cancer. To better understand the role of 13q deletion in prostate cancer we took advantage of our large prostate cancer tissue microarray comprising more than 12 000 cancer samples with full pathological and clinical follow‐up data. Fluorescence in situ hybridization with probes for ENOX1 (13q14.11) and the retinoblastoma gene (RB1, 13q14.2) was employed. A 13q deletion was found in 21% of 7375 analyzable cancers. Deletions were always heterozygous and associated with high Gleason grade (P < .0001), advanced tumor stage (P < .0001), high preoperative prostate‐specific antigen (PSA) levels (P = .0125), lymph node metastasis (P = .0377), positive resection margin (P = .0064), and early biochemical recurrence (P < .0001). 13q deletions were marginally more frequent in prostate cancers with negative ERG status (22.9%) than in ERG‐positive tumors (18.7%; P < .0001). Loss of 13q predicted patient prognosis independently from established prognostic parameters that are available at the time of biopsy (P = .0004), including preoperative PSA level, clinical tumor stage, and biopsy Gleason grade. In summary, the results of our study identify 13q deletion as a frequent event in prostate cancer, which is linked to an adverse phenotype and poor prognosis in this disease.     

Mapping of a gene for nonspecific X‐linked mental retardation (MRX 75) to Xq24–q26

Nonspecific X‐linked mental retardation is a heterogeneous condition consisting of non‐syndromal mental retardation in males. It is caused by mutation in one of several genes on the X chromosome (MRX genes). Here we report on the localization of a presumptive MRX gene to chromosomal region Xq24–q26 in a German family with nonspecific X‐linked mental retardation (MRX 75, HUGO Human Gene Nomenclature Committee). Two point linkage analysis with 23 informative markers gave a lod score of 2.53 at Θ = 0 for markers DXS425, DXS1254, DXS1114, and HPRT. Am. J. Med. Genet. 93:290–293, 2000. © 2000 Wiley‐Liss, Inc.     

Refining critical regions in 15q24 microdeletion syndrome pertaining to autism

Chromosome 15q24 microdeletion syndrome is characterized by developmental delay, facial dysmorphism, hearing loss, hypotonia, recurrent infection, and other congenital malformations including microcephaly, scoliosis, joint laxity, digital anomalies, as well as sometimes having autism spectrum disorder (ASD) and attention deficit hyperactivity disorder. Here, we report a boy with a 2.58‐Mb de novo deletion at chromosome 15q24. He is diagnosed with ASD and having multiple phenotypes similar to those reported in cases having 15q24 microdeletion syndrome. To delineate the critical genes and region that might be responsible for these phenotypes, we reviewed all previously published cases. We observe a potential minimum critical region of 650 kb (LCR15q24A‐B) affecting NEO1 among other genes that might pertinent to individuals with ASD carrying this deletion. In contrast, a previously defined minimum critical region downstream of the 650‐kb interval (LCR15q24B‐D) is more likely associated with the developmental delay, facial dysmorphism, recurrent infection, and other congenital malformations. As a result, the ASD phenotype in this individual is potentially attributed by genes particularly NEO1 within the newly proposed critical region.     

Influence of whole arm loss of chromosome 16q on gene expression patterns in oestrogen receptor-positive, invasive breast cancer

A whole chromosome arm loss of 16q belongs to the most frequent and earliest chromosomal alterations in invasive and in situ breast cancers of all common subtypes. Besides E-cadherin, several putative tumour suppressor genes residing on 16q in breast cancer have been investigated. However, the significance of these findings has remained unclear. Thus, other mechanisms leading to gene loss of function (eg haploinsufficiency, or distortion of multiple regulative subnetworks) remain to be tested as a hypothesis. To define the effect on gene expression of whole-arm loss of chromosome 16q in invasive breast cancer, we performed global gene expression analysis on a series of 18 genetically extensively characterized invasive ductal breast carcinomas and verified the results by quantitative real-time PCR (qRT-PCR). The distribution of the differential genes across the genome and their expression status was studied. A second approach by qRT-PCR in an independent series of 30 breast carcinomas helped to narrow down the observed effect. Whole-arm chromosome 16q losses, irrespective of other chromosomal changes, are associated with decreased expression of a number of candidate genes located on 16q (eg CDA08, CGI-128, SNTB2, NQO1, SF3B3, KIAA0174, ATBF1, GABARAPL2, KARS, GCSH, MBTPS1 and ZDHHC7) in breast carcinomas with a low degree of genetic instability. qRT-PCR provided evidence to suggest that the expression of these genes was reduced in a gene dosage-dependent manner. The differential expression of the candidate genes according to the chromosomal 16q-status vanished in genetically advanced breast cancer cases and changed ER status. These results corroborate previous reports about the importance of whole-arm loss of chromosome 16q in breast carcinogenesis and give evidence for the first time that haploinsufficiency, in the sense of a gene dosage effect, might be an important contributing factor in the early steps of breast carcinogenesis.