乳腺癌组织BRCA1,BRCA1基因区域杂合性缺失的研究

目的 研究乳腺癌组织ＢＲＣＡ１、ＢＲＣＡ２基因区域的杂合性缺失（ＬＯＨ）情况。方法 采用聚合酶链式反应（ＰＣＲ）和聚丙烯酰胺凝胶电泳,对３０例散发性乳腺癌和２例姐妹乳腺癌进行ＬＯＨ的检测,同时还采用Ｇ显带法对姐妹乳腺癌患者的外周血淋巴细胞染色体畸变情况进行分析。结果 在散发性乳腺癌中,ＢＲＣＡ１、ＢＲＣＡ２基因区域的杂合性缺失率分别为６．１２％和５．７７％;姐妹二人乳腺癌组织在ＢＲＣＡ２基因区域的     

中国乳腺癌家族BRCA1突变分析

为了探讨中国乳腺癌家族中BRCAl基因突变情况,我们收集了15个乳腺癌家系,共41个对象,其中23例为乳腺癌患者,采用聚合酶链反应-单链构像多态性分析(PCR-SSCP)、直接DNA测序法对BRCA1编码基因进行了全序列分析。结果发现在15个家系中有4例(3种)基因突变,突变比例为26.7％(4/15)。其中一例2228insC为插入突变,致编码子711处蛋白截短;另3例(2种)突变为1884A→T和3232 A→G,分别引起单个氨基酸改变。我们认为BRCA1为家族性乳腺癌的遗传基因;在BRCA1以外还存在其他的乳腺癌易感基因。     

231例乳腺癌患者乳腺癌易感基因 BRCA1 的突变检测及分析

目的：研究中国妇女BRCA1基因突变与遗传性、家族性和早发性乳腺癌的关系。方法：选取231例乳腺癌患者石蜡标本,显微切割提取癌组织,酚抽提法提取DNA,紫外分光光度仪测定DNA纯度及含量,PCR扩增exon2、exon11和exon20片段直接测序,与基因库序列比对分析其突变情况。结果：231例乳腺癌中发现突变33例,突变率为14．28％,统计分析发现,≤35岁年龄组与36－45岁组比较,P值为0．724,无统计学差异。46－55岁年龄组与＞55岁组比较,P 值为0．868,亦无统计学差异。将上述两组合并后统计发现,≤45岁年龄组患者突变率高于＞45岁组患者,P值为0．002,有显著统计学差异。结论：BRCA1突变与乳腺癌尤其是早发性乳腺癌密切相关。     

BRCA1和BRCA2基因与乳腺癌相关的研究进展

BRCA1和BRCA2基因是与乳腺癌尤其是遗传性乳腺癌发生发展密切相关的抑癌基因.研究表明,部分乳腺癌患者存在BRCA1和BRCA2基凶突变,而且出现这两个基因突变的乳腺癌表现出不同的病理学特点.通过检测乳腺癌患者BRCA1和BRCA2基因的突变情况,将有助于对乳腺癌患者预后的早期评估.     

乳腺癌易感基因BRCA1和BRCA2的突变检测及其临床意义

乳腺癌易感基因BRCA1、BRCA2在家族性和遗传性乳腺癌中突变率较高。现就其功能、检测及临床应用方面的研究进展作一综述。     

卵巢癌细胞系BRCA1蛋白表达的雌激素调控

目的：观察不同浓度雌激素对卵巢癌细胞系乳腺癌／卵巢癌易感基因（BRCAI）蛋白表达的影响。方法：采用免疫组化及计算机图象分析方法，检测体外不同浓度（10－9mol／L~10－6mol／L．）的17－β雌二醇（F2）对卵巢癌OVCAR3和SKOV3细胞系BRCA1蛋白表达的影响。结果：OVCAB3和SKOV3细胞在E2的作用下，BRCA1的表达明显增加，且呈现正性剂量效应关系。结论：雌激素能够诱导卵巢癌OVCAB3和SKOV3细胞系BRCA1蛋白的表达，可通过该方法探索治疗卵巢癌的新途径。     

353例遗传性高危乳腺癌患者BRCA1、BRCA2、PALB2基因胚系突变的分布情况研究

[目的]通过对女性乳腺癌患者进行胚系基因检测,评估BRCA1、BRCA2、PALB2基因胚系致病/可能致病性突变在高危乳腺癌患者中的分布情况。[方法]收集2016年12月1日至2022年4月30日中山大学附属第一医院收治的女性乳腺癌患者,对已进行胚系多基因检测的353例具有遗传性高危因素的女性乳腺癌患者,对她们的检测结果进行分析,评估BRCA1、BRCA2和PALB2基因胚系致病/可能致病性突变患者的病理和临床特征等情况。[结果] 353例患者中,胚系BRCA1、BRCA2和PALB2致病/可能致病突变者共59例,突变率为16.71%,年轻患者较其他年龄患者的BRCA1突变率更高（P=0.039）,相比其他分子分型,三阴性乳腺癌患者的BRCA1突变（P<0.001）和3个基因的总突变率（P=0.007）都明显更高。和没有肿瘤家族史的患者相比,有肿瘤家族史的患者并没有体现出明显的高突变率。具有2个或2个以上危险因素的患者的基因突变率要明显高于只有1个高危因素的患者（P=0.048）。[结论] PALB2基因胚系致病/可能致病突变在高危乳腺癌患者中的发生比例较高,其重要性并不亚于BR...     

中国BRCA1和BRCA2基因胚系突变乳腺癌的临床病理特征比较

  目的   比较中国人群中BRCA1和BRCA2基因两种突变状态的乳腺癌患者临床病理特征的差异。   方法   收集2003年10月至2015年5月北京大学肿瘤医院收治的8 627例连续的、未经家族史和年龄选择的原发性乳腺癌患者资料,经过基因测序共有521例患者携带BRCA1/2基因致病性胚系突变,其中BRCA1突变患者203例,BRCA2突变患者318例。对这些突变患者的临床病理参数进行回顾性分析。   结果   乳腺癌患者中BRCA2基因突变频率（3.7%）高于BRCA1（2.4%）。BRCA1突变者乳腺癌发病年龄比BRCA2突变者早（中位发病年龄:43.0岁 vs. 47.0岁,P<0.01）。BRCA1突变乳腺癌患者组织学分级Ⅲ级比例显著高于BRCA2突变患者（36.2% vs. 18.4%,P<0.01）,三阴性乳腺癌（ER-/PR-/HER2-）比例也显著高于BRCA2突变者（59.2% vs. 15.4%,P<0.01）。BRCA2突变患者的腋窝淋巴结阳性比例高于BRCA1突变患者（41.8% vs. 29.6%,P<0.01）。   结论   中国BRCA1和BRCA2胚系突变乳腺癌的临床病理特征存在一定差异,提示BRCA1和BRCA2胚系突变对乳腺癌生物学行为的影响可能不同,为BRCA1和BRCA2胚系突变乳腺癌更加精准的临床管理提供依据。       

BRCA1基因研究的新进展

BRCA1作为乳腺癌、卵巢癌易感基因自 1 994年被分离克隆以后 ,研究者们一直在致力于揭示其生物学功能。据估计 ,约 2 .5%～ 5%的乳腺癌、1 0 %的早发性乳腺癌、40 %～ 50 %的遗传性乳腺癌、90 %的乳腺、卵巢癌家系及少量的卵巢癌、前列腺癌、肠癌可以用 BRCA1基因生殖细胞突变来解释 [1] 。在已建立的乳腺癌信息中心 BCI(The Breast Cancerlnformation Core http:∥ www.nhgri.nih.gov/Intramural- research/Lab- transfer/Bic/)的 BRCA1突变数据库中已有 1 0 0 0多条序列变异的记录 ,它们包括散布于整个基因编码区的突变 (缺失、…     

Mutation analysis of the BRCA1 gene in Japanese patients with sporadic ovarian cancer

Background. Germline mutations in the BRCA1 gene, on chromosome 17q21, confer susceptibility to hereditary breast and ovarian cancer. It remains uncertain, however, whether somatic mutations in BRCA1 play a role in sporadic ovarian carcinogenesis. Methods. Samples of tumor and normal (peripheral blood) DNA were collected from 19 patients with sporadic (that is, no known family history) ovarian cancer. The BRCA1 gene alteration was analyzed for the entire coding region, using the single-strand conformation polymorphism (SSCP) technique followed by direct sequencing. Results. We found two somatic mutations in the 19 patients. One was an A deletion at nucleotide position 2073, leading to premature truncation of BRCA1 protein at codon 700, and the other was a G-to-A transition at nucleotide position 4498, resulting in substitution of serine for aspartic acid at codon 1460. In addition, loss of heterozygosity (LOH) was also observed at a BRCA1 intragenic marker in samples of both tumor and blood. Conclusion. Our data suggest that somatic mutation of the BRCA1 gene, in conjunction with LOH, may be a critical event in the genesis of a subgroup of sporadic ovarian cancer. Received: June 4, 1999 / Accepted: July 30, 1999     

38例散发乳腺癌患者BRCA1基因突变检测

目的：分析３８例散发乳腺癌患者ＢＲＣＡ１基因突变情况及突变位置。方法：应用ＰＣＲ－ＳＳＣＰ（Ｓｉｎｇｌｅ－ｓｔｒａｎｄｅｄ ｃｏｎｆｏｒｍａｔｉｏｎａｌ ｐｏｌｙｍｏｒｐｈｉｓｍ,ＳＳＣＰ）和直接测序方法。结果：４／３８例患者ＢＲＣＡ１基因有突变,突变例数占总例和的１０．５％,其中３例突变位置在内含子的拼接区,一例突变位置在１１号外显子上。结论：筛查ＢＲＣＡ１基因突变对于乳腺癌患病风险评估,发病检     

散发性乳腺癌患者BRCA1基因突变分析

目的 :探讨BRCA1基因突变在散发性乳腺癌发生和发展中的作用及在乳腺癌临床诊断和治疗中的应用前景。方法 :应用PCR SSCP和直接测序法检测 3 0例散发性乳腺癌和 15例正常乳腺组织中BR CA1基因外显子 2、11和 2 0的突变情况。结果 :15例正常乳腺组织在 3个外显子上都未显示电泳异常 ,3 0例乳腺癌中有 6例在外显子 2上显示电泳条带异常 ,其中 4例经测序证实有突变 ,1例在外显子 2上 ,3例在内含子拼接区。BRCA1基因突变率在初诊年龄、临床分期和肿瘤体积上差异无统计学意义 ,但与肿瘤转移密切相关。结论 :BRCA1基因突变与散发性乳腺癌的发生和发展密切相关 ,该基因突变筛查可作为一种预后指标。     

186例乳腺癌患者BRCA1基因突变检测

目的 分析186例散发乳腺癌患者肿瘤易感基因BRCA1（breast and orarian cancer susceptibility gene,BRCA1)突变情况及突变位置。方法 应用PCR－SSCP（single-stranded canformational polymorphs,SSCP)和直接测序方法定位,检测乳腺癌部分患者部分BRCA1基因外显子和内含子与外显子之间接拼区突变及突变位置。结果 186例患者中,有13例发生BRCA1基因突变,突变例数占总例数的7．0％,其中8例突变位置在内含子与外显子的拼接区,5例突变位置在外显子上。结论 筛查BRCA1基因突变对于乳腺癌患病风险评估、发病检测、早期诊断及基因治疗具有重要的临床意义。     

Analysis of the mutations of BRCA1 gene in 38 breast cancer patients

目的： 分析３８ 例散发乳腺癌患者 Ｂ Ｒ Ｃ Ａ１ 基因突变情况及突变位置。方法： 应用 Ｐ Ｃ Ｒ Ｓ Ｓ Ｃ Ｐ（ Ｓｉｎｇｌｅｓｔｒａｎｄｅｄ ｃｏｎｆｏｒｍａｔｉｏｎａｌ ｐｏｌｙｍｏｒｐｈｉｓｍ , Ｓ Ｓ Ｃ Ｐ） 和直接测序方法。结果：４／３８ 例患者 Ｂ Ｒ Ｃ Ａ１ 基因有突变,突变例数占总例数的１０ ．５ ％ ,其中３ 例突变位置在内含子的拼接区,一例突变位置在１１ 号外显子上。结论：筛查 Ｂ Ｒ Ｃ Ａ１ 基因突变对于乳腺癌患病风险评估、发病检测、早期诊断及基因治疗具有重要的临床意义。     

Mutation analysis of the hMTH1 gene in sporadic human ovarian cancer

8-oxo-deoxyguanosine triphosphate (8-oxo-dGTP) is a major oxidation product in the nucleotide pool of the cell and is a potent mutagen, because it can be incorporated into DNA with equal frequency opposite either template C or A. The human MTH1 gene (hMTH1) is a homologue of the E. coli mutator gene mutT, which encodes 8-oxo-dGTPase. hMTH1 protein reduces spontaneous mutations by removing 8-oxo-dGTP from the triphosphate pool. To determine whether this gene is associated with carcinogenesis of human ovarian cancer, the present study examined, for the first time, the hMTH1 sequence in 49 ovarian cancers and 9 ovarian cancer cell lines by means of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequencing analyses. A Gright curved arrow A transition at codon 83 was detected in one patient and one cell line (3.4%), followed by an amino acid change (valineright curved arrow methionine) which was known to cause the protein to be less active in vitro. This one base substitution was found in normal and corresponding tumor DNA, and its allele type was heterozygous. The same change has been detected in HNPCC (hereditary non-polyposis colorectal cancer) and gastric cancer patients, and thus it may not represent a mutation specific for ovarian cancer. A silent Tright curved arrow C transition at codon 119 was detected in 12 patients and 2 cell lines (24.1%). No specific mutations in hMTH1 were found in either ovarian cancer patients or cell lines. Thus, it appears that hMTH1 is not directly associated with ovarian cancer.     

Mutation analysis of the Smad3 gene in human ovarian cancers.

The Smad3 gene is a member of the Smad family, vertebrate homologues of Drosophila Mad, and its gene product is a cytoplasmic element in the transforming growth factor-beta (TGF-beta) signaling pathway. Mutations in TGF-beta receptors and their cytoplasmic elements of transduction signals commonly accompany various cancers. Using PCR-SSCP analysis we searched for the presence of Smad3 gene mutations in 36 human ovarian cancers, and found that 15 cases (41. 7%) had a polymorphism at codon 103. Because this mutation was not accompanied by amino acid replacement, the present results show that the mutations in the Smad3 gene are unlikely to be involved in human ovarian cancers.     

BRCA1 and BRCA2 mutations in breast cancer families with multiple primary cancers.

Ninety-eight women ascertained from high-risk breast/ovarian cancer clinics with breast cancer reporting at least one other primary cancer in themselves or in a relative with breast cancer were compared with 99 women with breast cancer who reported a family history of breast cancer only. All DNA was screened for coding region mutations in BRCA1 and BRCA2 using heteroduplex analysis, followed by direct sequencing. Our data indicate that 42.9% of families reporting breast and any second nonbreast type of primary cancer in the same individual had a BRCA1 or BRCA2 mutation, as compared with the 12.1% of families reporting breast cancer only (P < 0.001). Among the 66 women reporting breast cancer and a nonovarian second primary cancer, 15 (22.7%) had mutations in BRCA1 or BRCA2 (P = 0.04). Among the 32 families where ovarian cancer was the second primary cancer, 27 (84.4%) had a mutation in BRCA1 or BRCA2 (P < 0.001). BRCA1 and BRCA2 mutations were twice as common in the presence of a reported second nonovarian cancer. These data suggest that the presence of multiple primary cancer of any kind may predict for an increased likelihood of finding a BRCA1 or BRCA2 mutation and supports previous studies suggesting that BRCA1 and BRCA2 mutations may be associated with an increased susceptibility to cancers other than breast and ovarian cancer.     

Mutation analysis of BRCA1 and BRCA2 cancer predisposition genes in radiation hypersensitive cancer patients

PURPOSE: The dose intensity of radiotherapy (RT) used in cancer treatment is limited in rare individuals who display severe normal tissue reactions after standard RT treatments. Novel predictive assays are required to identify these individuals prior to treatment. The mechanisms responsible for such reactions are unknown, but may involve dysfunction of genes involved in the sensing and response of cells to DNA damage. The breast cancer susceptibility genes BRCA1 and BRCA2 are implicated in DNA damage repair and the control of genome stability. The purpose of this study was to determine if clinical radiation hypersensitivity is related to mutations of the BRCA1 and BRCA2 genes. Such information is of potential use in the clinical management of BRCA mutation carriers and their families. METHODS AND MATERIALS: Twenty-two cancer patients who developed severe normal tissue reactions after RT were screened for mutations of BRCA1 and BRCA2, using various methods including protein truncation testing, direct DNA sequencing, and a PCR-based BRCA1 exon 13 duplication test. RESULTS: No mutations were detected in the 22 patients tested, despite screening for the majority of commonly described types of mutations of BRCA1 and BRCA2. CONCLUSION: These early results suggest that genes other than BRCA1 and BRCA2 probably account for most cases of clinical radiation hypersensitivity, and that screening for mutations of BRCA1 and BRCA2 is unlikely to be useful in predicting response to radiotherapy. However, it has not been excluded that some BRCA1 or BRCA2 heterozygotes might experience unexpected RT toxicity; further BRCA mutation screening on radiation sensitive individuals is warranted.