Frequency of three BRCA1 gene founder mutations in breast/ovarian cancer families from the Pomerania-Kujawy region of Poland

A group of 63 families from the Pomerania-Kujawy region were analyzed for three BRCA1 gene Polish founder mutations, 5382insC, 300T>G, and 4153delA, because of breast (BrCa) and/or ovarian cancer (OvCa) history. The analysis was carried out by multiplex polymerase chain reaction method. BRCA1 mutation was revealed in nine (14%) families: in three (33%) of hereditary BrCa and OvCa families, in three (8%) of hereditary BrCa families, and in three (21%) of hereditary OvCa families. According to risk criteria, it was revealed in 45% of high-risk families with more than three cancers, 13% of moderate-risk families with two cancers, and 8% of families with sporadic OvCa. In six families, the mutation was found in a proband with BrCa or OvCa and in three families, the mutation was found in a healthy proband, first-degree relative of a patient deceased of BrCa or OvCa. 5382insC frameshift mutation accounted for 67% and 300T>G missense mutation for 33% of all identified familial mutations. 4153delA frameshift mutation was not found in analyzed sample of families. 5382insC mutation was found in 9% and 300T>G in 5% of all investigated families, and in 27 and 18%, respectively, of high-risk families. This underlines the importance of applying strict inclusion criteria to analyze mutation frequency in hereditary BrCa/OvCa families.     

前列腺癌细胞中NSBP1基因表达上调

明确用mRNA差异显示技术（mRNA-DD）筛选出的前列腺癌相关基因（Nucleosomal Binding Protein 1）在前列腺癌细胞系的表达情况。在GenBank NR数据库中对筛选出的5条差异表达序列标签（EST）进行同源性分析,其中1条与已知基因NSBP1高度同源（97%）。半定量RT-PCR结果显示在LNCaP、DU145及PC-3前列腺癌细胞系中NSBP1 mRNA的表达水平分别高于正常前列腺组织2.5倍,3.4倍和3.6倍,与Northern杂效分析结果趋势一致。7例前列腺癌组织的PT-PCR结果也体现了相同的表达趋势,NSBP1表达较配对正常前列腺癌组织增高,差异有统计学意义。以上结果表明NSBP1基因在前列腺癌组织系和组织中的表达均明显高于正常列腺癌组织,NSBP1表达上调可能参与了前列腺癌的发生发展过程。     

Cancer predisposing missense and protein truncating BARD1 mutations in non‐BRCA1 or BRCA2 breast cancer families

Fifteen years ago BRCA1 and BRCA2 were reported as high penetrant breast cancer predisposing genes. However, mutations in these genes are found in only a fraction of high risk families. BARD1 is a candidate breast cancer gene, but only a limited number of missense mutations with rather unclear pathogenic consequences have been reported.We screened 196 high risk breast cancer families for the occurrence of BARD1 variants. All genetic variants were analyzed using clinical information as well as IN SILICO predictive tools, including protein modeling. We found three candidate pathogenic mutations in seven families including a first case of a protein truncating mutation (p.Glu652fs) removing the entire second BRCT domain of BARD1. In conclusion, we provide evidence for an increased breast cancer risk associated to specific BARD1 germline mutations. However, these BARD1 mutations occur in a minority of hereditary breast cancer families. ©2010 Wiley‐Liss, Inc.     

Bif-1对前列腺癌LNCap细胞生物学行为的影响

目的研究Bif-1基因的过表达对前列腺癌细胞凋亡、增殖以及迁移过程的影响。方法构建Bif-1基因全克隆并转染LNCap细胞,上调细胞中Bif-1基因的表达水平,通过流式细胞术检测细胞转染前后的细胞凋亡情况;通过MTT法检测细胞的增殖能力变化;通过划痕试验检测细胞迁移能力的变化。结果转染Bif-1基因后,Real-time PCR检测发现LNCap细胞中Bif-1基因mRNA水平△△CT高于对照组10倍以上;Western blotting条带光密度值提高2倍以上。实验组细胞凋亡比例升高至31.90%,细胞增殖能力减弱。实验组和对照组中LNCap细胞划痕愈合速度基本相同,差异无统计意义（P〉0.05）。结论 Bif-1基因在LNCap细胞中的过表达促进了细胞凋亡,抑制细胞的增殖能力,而对前列腺癌细胞的迁移能力无显著影响。基因有可能作为一个潜在的前列腺癌治疗靶点。     

PIM-1蛋白激酶在前列腺癌组织中的表达

目的观察原癌基因PIM1表达产物PIM1蛋白激酶在前列腺癌组织、良性前列腺增生组织及正常前列腺组织中的表达。方法应用免疫组织化学方法测定37例前列腺癌组织、26例良性前列腺增生组织及12例正常前列腺组织中PIM1蛋白激酶的表达。结果PIM1蛋白激酶在前列腺癌组织、良性前列腺增生组织及正常前列腺组织中的阳性表达例数分别是29例(78.38%),11例(42.31%)和3例(25.00%)。前列腺癌组PIM1的表达显著高于良性前列腺增生组及正常前列腺组(P<0.001)。结论原癌基因PIM1及其产物PIM1蛋白激酶有可能在前列腺癌的发生发展中发挥重要作用。     

前列腺癌中巨嗜细胞抑制细胞因子-1基因的表达及意义

目的评估巨嗜细胞抑制细胞因子-1（MIC-1）在前列腺癌细胞系和前列腺癌组织中的表达情况，并明确其表达水平和临床病理学参数间的关系。方法用RT-PCR及免疫组化方法检测MIC-1在LNCaP、PC-3细胞系和前列腺癌组织中的表达。结果MIC-1在LNCaP细胞系中高表达，在前列腺癌组织中的表达水平明显高于增生和正常前列腺组织（P〈0．001）。MIC-1基因表达水平和前列腺癌临床分期、Gleason评分、PSA水平、前列腺体积以及患者年龄均无明显相关性。结论MIC-1蛋白可能将成为前列腺癌诊断新的肿瘤标记物。     

Altered expression of syndecan-1 in prostate cancer

Syndecan-1 is a cell surface heparan sulfate proteoglycan expressed by epithelial cells. It interacts with growth factors, matrix components, and other extracellular proteins, and is thought to be involved in processes such as cell growth, differentiation and adhesion. The expression of syndecan-1 appears generally downregulated in human carcinomas and in experimental cancer models, whereas transfectional expression of syndecan-1 in cultured cancer cells has been shown to inhibit their growth and other aspects of malignant behavior. These findings suggest that analysis of syndecan-1 expression might be of prognostic value in cancer diagnosis, and studies on some carcinomas indeed point to an inverse correlation between syndecan-1 expression and cancer prognosis. So far, little information has been available on the expression of syndecan-1 in human prostate and prostate disease. We have generated and characterized novel antibodies against syndecan-1 and applied them to immunohistochemical staining of specimens representing normal prostate as well as benign and malignant (n=23) prostate disease. The results indicate that syndecan-1 expression is altered but not uniformly absent in prostate cancer, which is in contrast to the expression of high-molecular-weight cytokeratins. The data initially suggest an inverse correlation between syndecan-1 expression and Gleason grade of the tumor, and warrant a larger study to assess the potential prognostic value of analysing syndecan-1 expression in prostate carcinoma.     

FBI-1基因在前列腺癌中的研究进展

原癌基因FBI-1又称ZBTB7、LRF和Pokemon,其编码产物属于POK蛋白家族成员,具有转录抑制功能.过度表达的FBI-1可以通过其特殊的蛋白质结构组成抑制Rb基因及ARF基因的表达,并且其在肿瘤的发生、发展及转归上具有重要作用.近年来,有很多医学机构对FBI-1基因与前列腺肿瘤进行了研究.原癌基因FBI-1有望成为肿瘤预防、诊断、治疗、预后评价的新靶标.     

前列腺癌非编码RNA1在雄激素非依赖去势抵抗型前列腺癌细胞中的作用

目的 探讨长链非编码RNA前列腺癌非编码RNA1(PRNCR1)在雄激素非依赖的前列腺癌细胞中的作用.方法 应用实时定量PCR(qRT-PCR)检测雄激素依赖的前列腺癌细胞LNCaP及雄激素非依赖的前列腺癌细胞C4-2中PRNCR1的表达情况,通过RNA干扰技术沉默C4-2细胞中的PRNCR1,Western blot技术检测C4-2细胞中雄激素受体(AR)的表达变化,流式细胞术检测细胞凋亡的变化,MTT实验检测沉默PRNCR1表达对细胞增殖的影响,Transwell侵袭实验检测细胞侵袭能力的变化.结果 PRNCR1在雄激素非依赖的细胞系C4-2中高表达,干扰其表达可以明显降低前列腺癌细胞中AR的表达,抑制前列腺癌细胞的细胞增殖及细胞的侵袭能力,并促进细胞的凋亡.结论 PRNCR1介导AR在前列腺癌去势抵抗中发挥着重要作用.     

Prevalence of BRCA1 and BRCA2 mutations in unselected breast cancer patients from Peru

The prevalence of BRCA1 and BRCA2 mutations among breast cancer patients in Peru has not yet been explored. We enrolled 266 women with breast cancer from a National cancer hospital in Lima, Peru, unselected for age or family history. DNA was screened with a panel of 114 recurrent Hispanic BRCA mutations (HISPANEL). Among the 266 cases, 13 deleterious mutations were identified (11 in BRCA1 and 2 in BRCA2), representing 5% of the total. The average age of breast cancer in the mutation‐positive cases was 44 years. BRCA1 185delAG represented 7 of 11 mutations in BRCA1. Other mutations detected in BRCA1 included: two 2080delA, one 943ins10, and one 3878delTA. The BRCA2 3036del4 mutation was seen in two patients. Given the relatively low cost of the HISPANEL test, one should consider offering this test to all Peruvian women with breast or ovarian cancer.     

Routine testing for PALB2 mutations in familial pancreatic cancer families and breast cancer families with pancreatic cancer is not indicated

PALB2-mutation carriers not only have an increased risk for breast cancer (BC) but also for pancreatic cancer (PC). Thus far, PALB2 mutations have been mainly found in PC patients from families affected by both PC and BC. As it is well known that the prevalence of gene mutations varies between different populations, we studied the prevalence of PALB2 mutations in a Dutch cohort of non-BRCA1/2 familial PC (FPC) families and in non-BRCA1/2 familial BC (FBC) families with at least one PC case. Mutation analysis included direct sequencing and multiplex ligation-dependent probe amplification (MLPA) and was performed in a total of 64 patients from 56 distinct families (28 FPC families, 28 FBC families). In total, 31 patients (48%) originated from FPC families; 24 were FPC patients (77%), 6 had a personal history of BC (19%) and 1 was a suspected carrier (3.2%). The remaining 33 patients (52%) were all female BC patients of whom 31 (94%) had a family history of PC and 2 (6.1%) had a personal history of PC. In none of these 64 patients a PALB2 mutation was found. Therefore, PALB2 does not have a major causal role in familial clustering of PC and BC in non-BRCA1/2 families in the Dutch population.     

Screening E-cadherin in gastric cancer families reveals germline mutations only in hereditary diffuse gastric cancer kindred

The International Gastric Cancer Linkage Consortium (IGCLC) predicted that up to 25% of families fulfilling the criteria for hereditary diffuse gastric cancer (HDGC) would harbor CDH1 germline mutations. This was based on observations from the low number of diffuse gastric cancer families described at the time, and its validation would require analysis of larger numbers. Here we report the results of germline CDH1 mutation screening in 39 kindred with familial aggregation of gastric cancer, a subset of which fulfills the criteria defined by the IGCLC for HDGC. CDH1 germline mutations were detected in four of 11 (36.4%) HDGC families. No mutations were identified in 63.6% of HDGC families or in kindred with familial aggregation of gastric cancer not fulfilling criteria for HDGC. These results add support to the evidence that only HDGC families harbor germline mutations in CDH1 and that genes other than CDH1 remain to be identified.     

Characterization of CHEK2 mutations in prostate cancer

The checkpoint kinase 2 (CHEK2, also known as CHK2) is a tumor suppressor that participates in the DNA damage-signaling pathway. It is phosphorylated and activated following DNA damage, resulting in cell cycle arrest and apoptosis. Previously, we reported germline CHEK2 mutations in patients with prostate cancer. In this study, we have identified two novel somatic CHEK2 mutations, c.349A > G (p.R117G) and c.967A > C (p.E321K), in prostate tumor specimens and investigated the functions of these mutants in vivo. We have shown that most of the germline CHEK2 mutations and one somatic mutation (p.R117G) within FHA domain have modestly reduced CHEK2 kinase activity in comparison with wild-type CHEK2 while the other somatic mutation (p.E321K) within the kinase domain of CHEK2 totally abolished CHEK2 kinase activity. Given that several clinical CHEK2 mutations reside in the Forkhead-associated (FHA) domain, we further generated a series of missense mutations within this domain and demonstrated the requirement of an intact FHA domain for the full activation of CHEK2. Taken together, these results provide evidence that both germline and somatic CHEK2 mutations identified in prostate cancer may contribute to the development of prostate cancer through the reduction of CHEK2 activation in response to DNA damage and/or oncogenic stress.     

DGGE screening of mutations in mismatch repair genes (hMSH2 and hMLH1) in 34 Swedish families with colorectal cancer

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominantly inherited syndrome which confers an increased risk for colorectal cancer and endometrial cancer as well as other tumors. It is caused by germline DNA mismatch repair (MMR) gene mutations in five MMR genes, hMSH2, hMLH1, hPMS1, hPMS2 and hMSH6. Finding mutations in these high risk families means that you can offer presymptomatic carrier diagnosis and thereby identify individuals with a very high risk for cancer. These persons benefit from counseling and should be offered surveillance. We have used DGGE to screen members from 34 families for mutations in hMLHl and hMSH2. Six mutations in five families were found, five of these mutations are new. Besides, three new polymorphisms were identified. The mutations were found in two of seven Amsterdam criteria HNPCC families and in three of four families with at least one case of early onset of CRC (before 35), suggesting there are apporopriate families to be chosen for mutation screening in MMR genes.     

Two families with nonsyndromic low-frequency hearing loss harbor novel mutations in Wolfram syndrome gene 1

Although hereditary hearing loss is highly heterogeneous, only a few loci have been implicated with low-frequency hearing loss. Mutations in one single gene, Wolfram syndrome 1 (WFS1), have been reported to account for most familial cases with this type of hearing impairment. This study was conducted to determine the cause of nonsyndromic low-frequency hereditary hearing impairment in two large families. Two large families from Switzerland and United States with low-frequency hearing loss were identified. Genomewide linkage analysis was performed followed by mutation screening in the candidate gene WFS1 with direct DNA sequencing and restriction fragment analysis. Both families were linked to DFNA6/14/38 with lod scores>3. Two novel heterozygous missense mutations in WFS1 were identified: c.2311G>C leading to p.D771H in the Swiss family and c.2576G>C leading to p.R859P in the US family. The sequence alteration was absent in 100 control chromosomes. Nonsyndromic low-frequency hereditary hearing impairment seems to be predominantly a monogenic disorder due to WFS1. We confirm that most mutations in WFS1 associated with isolated low-frequency hearing loss are clustered in the C-terminal protein domain coded by exon 8.     

Germline mutations of E-cadherin gene in Korean familial gastric cancer patients

Gastric cancer is the most common cancer in Korea. Germline mutations of the E-cadherin gene have recently been identified in familial gastric cancer patients. We screened five Korean familial gastric cancer patients to investigate germline mutations of the E-cadherin gene. These patients fulfilled the following criteria: presence of at least two gastric cancer patients within first-degree relatives and one patient diagnosed before the age of 50 years. Abnormal band patterns were found in exons 6 and 10 in two familial gastric cancer patients by polymerase chain reaction-single strand conformation polymorphism analysis (probands from the SNU-G2 and SNU-G1001 families, respectively). DNA sequencing analysis of the E-cadherin gene of these two patients revealed missense mutations in each exon. The SNU-G2 proband harbored a missense mutation from aspartic acid (GAT) to glycine (GGT) at codon 244 in exon 6 of the E-cadherin gene, and the SNU-G1001 proband had a missense mutation from valine (GTG) to alanine (GCG) at codon 487 in exon 10. The SNU-G2 proband was diagnosed with gastric cancer at the age of 38; three brothers and two sisters had died of gastric cancer under the age of 50, and their mother had died of gastric cancer at the age of 63. The SNU-G1001 proband was diagnosed with gastric cancer at the age of 42 and one brother had died of gastric cancer at the age of 49. In summary, we found germline mutations of the E-cadherin gene in two of five Korean familial gastric cancer patients screened. Received: January 4, 1999 / Accepted: February 4, 1999     

BRCA1 and BRCA2 mutations among familial breast cancer patients from Costa Rica

Gutiérrez Espeleta GA, Llacuachaqui M, García-Jiménez L, Aguilar Herrera M, Loáiciga Vega K, Ortiz A, Royer R, Li S, Narod SA. BRCA1 and BRCA2 mutations among familial breast cancer patients from Costa Rica. The contribution of mutations in BRCA1 and BRCA2 genes to the burden of breast cancer in Costa Rica has not been studied. We estimated the frequency of BRCA mutations among 111 Costa Rican women with breast cancer and a family history of breast cancer. These women were mainly from the metropolitan area of San José. A detailed family history was obtained from each patient and a blood sample was processed for DNA extraction. Mutations in BRCA1 and BRCA2 were sought using a combination of techniques and all mutations were confirmed by direct sequencing. Four different mutations were identified in five patients (four in BRCA2 and one in BRCA1) representing 4.5% of the total. Two unrelated patients were found to have a BRCA2 5531delTT mutation. Other BRCA2 mutations included C5507G and 6174delT. Only one BRCA1 mutation was found (C3522T). The family with the BRCA1 mutation had five cases of gastric cancer. Families with BRCA2 mutations were also reported to have cases of gastric and prostate cancers; however, the full range of cancers associated with BRCA1 and BRCA2 mutations in Costa Rica has not yet been established.     

Germline mutations of the CDKN2 gene in UK melanoma families

Germline mutations in CDKN2 on chromosome 9p21, which codes for the cyclin D kinase inhibitor p16, and more rarely, mutations in the gene coding for CDK4, the protein to which p16 binds, underlie susceptibility in some melanoma families. We have sequenced all exons of CDKN2 and analysed the CDK4 gene for mutations in 27 UK families showing evidence of predisposition to melanoma. Five different germline mutations in CDKN2 were found in six families. Three of the mutations (Met53Ile, Arg24Pro and 23ins24) have been reported previously. We have identified two novel CDKN2 mutations (88delG and Ala118Thr) which are likely to be associated with the development of melanoma, because of their co-segregation with the disease and their likely functional effect on the CDKN2 protein. In binding assays the protein expressed from the previously described mutation, Met53Ile, did not bind to CDK4/CDK6, confirming its role as a causal mutation in the development of melanoma. Ala118Thr appeared to be functional in this assay. Arg24Pro appeared to bind to CDK6, but not to CDK4. No mutations were detected in exon 2 of CDK4, suggesting that causal mutations in this gene are uncommon. The penetrance of these mutant CDKN2 genes is not yet established, nor is the risk of non-melanoma cancer to gene carriers.      

Germline and somatic NF1 gene mutations in plexiform neurofibromas

Neurofibromatosis type 1 (NF1), a common autosomal dominant neurogenetic disorder affecting 1 in 4000 individuals worldwide, results from functional inactivation of the 17q11.2-located NF1 gene. Plexiform neurofibroma (PNF) is a congenital benign tumour present in 30-50% of NF1 patients, which in about 10-15% of cases, can develop into a malignant peripheral nerve sheath tumour (MPNST). This study aimed to characterise the NF1 germline and somatic mutations associated with such tumours by DNA analysis in 51 PNFs resected from 44 unrelated NF1 patients. Germline mutations were identified in 35 patients, of which 21 were novel. Somatic NF1 mutations were found in 29 PNF DNAs, which included 9 point mutations, 5 being novel, and 20 tumour DNA samples exhibiting, either loss of heterozygosity (LOH) of the NF1 gene region (16 tumours), or complete or partial NF1 gene deletions analyzed by multiplex ligation-dependent probe amplification (MPLA) analysis. The type of NF1 germline mutations detected in patients with PNF were similar to those detected in most NF1 patients. LOH of the NF1 gene region, as identified by marker analysis and/or MLPA, was detected in only 20/29 (69%) PNFs, compared to the >90% LOH previously found in MPNST. This systematic analysis of the NF1 germline and somatic mutations associated with PNF development suggest that in most such tumours neither the NF1 somatic mutation type, nor its gene location, is influenced by the underlying NF1 germline mutation. Evidence for LOH involving the TP53 gene identified in the PNFs is also reported for the first time.