喉癌中EGFR基因扩增、表达及临床意义

目的研究喉癌中表皮生长因子受体(EGFR)基因的扩增、表达,探讨其在喉癌发生、发展中的作用及临床意义。方法采用差异PCR(differential PCR)方法检测40例喉鳞状细胞癌及配对癌旁正常组织中EGFR基因的扩增(即基因拷贝数增加);应用RT-PCR方法检测EGFR mRNA水平;应用SPSS13.0软件对数据进行统计学分析。结果喉癌组织中有13例(占32.5%)EGFR基因拷贝数增加,癌旁对照组中则未检测到(χ2=15.537,P<0.005);喉癌组织中EGFR mRNA平均积分光密度为872.356±62.340,癌旁对照组为346.425±57.380(t=5.959,P<0.001);喉癌组织分化程度越低,病理分期越晚,EGFR基因扩增和mRNA表达水平越高(P<0.05)。结论喉癌中EGFR基因在DNA水平上的扩增是EGFR mRNA过表达的原因之一,EGFR的扩增和过表达在喉癌的发生、进展中发挥一定作用。     

Frequent EGFR expression/EGFR amplification and lack of activating mutation in testicular choriocarcinoma

Choriocarcinoma (CC) is the rarest but most aggressive histological component of adult testicular germ cell tumor (TGCT). Although we previously reported a putative role of epidermal growth factor receptor (EGFR) alterations in the progression of CC, little is known about the kinase‐activating mutation status of EGFR, which predicts the response to EGFR‐tyrosine kinase inhibitors. In this study, we clinicopathologically reviewed a total of 12 cases of mixed TGCTs with CC components. Immunohistochemistry, fluorescence in situ hybridization, and direct sequencing was performed to investigate EGFR expression, EGFR copy number alterations, and functional mutation of EGFR in these CC components, respectively. Four (33%) of 12 cases exhibited predominant CC components (>50%), and all these patients died due to disease within 62 months. Overexpression of EGFR, higher copy number of EGFR, and amplification of EGFR was observed in 12 (100%), 10 (83%), and 9 (75%) of 12 CC components, respectively. None of the cases showed any mutational events in exons 18 to 24, which encode the tyrosine kinase domain of EGFR. These results confirm an important role of EGFR in the tumor aggressiveness of testicular CCs and may suggest its possible innate resistance against conventional anti‐EGFR therapies.     

肺鳞状细胞癌EGFR/ALK的基因状态

目的:探讨肺鳞状细胞癌各亚型中EGFR和ALK的基因状态.方法:应用ARMS方法检测肺鳞状细胞癌石蜡组织中EGFR基因突变和ALK融合基因情况.结果:218例肺鳞状细胞癌样本中,E GFR基因突变率为4.59％(10/218),19del和L858R各为2.29％(5/218).ALK融合基因阳性率为6.14％(7/114).结论:肺鳞状细胞癌存在一定比例EGFR基因突变和ALK融合基因阳性,肺鳞状细胞癌EGFR基因和ALK融合基因常规检测不可忽视.     

Uncommon GNAQ, MMP8, AKT3, EGFR, and PIK3R1 mutations in thyroid cancers

Frequent mutations in the GNAQ, MMP8, Akt3, EGFR, and PIK3R1 genes have been reported in human cancers but mostly have not been well examined in thyroid cancer. Selected exons of GNAQ, MMP8, AKT3, EGFR, and PIK3R1 genes were sequenced in various thyroid cancers. We found a G2203A EGFR mutation, resulting in a G735S amino acid change, in one of 21 (5%) papillary thyroid cancer samples. We did not find any mutation in the MMP8 gene, but observed a frequent SNP A259G (K87E) genotype switch in various types of thyroid cancer samples. We did not find any mutation in the GNAQ, AKT3, and PIK3R1genes in various types of thyroid cancer. No mutation in these genes was found in 12 cell lines derived from various types of thyroid cancer. Therefore, unlike in other cancers, mutations in these genes are uncommon in thyroid cancer.     

非小细胞肺癌患者ALK,EGFR及KRAS基因的检测及临床病理特征

目的:研究汉族非小细胞肺癌患者中间变性淋巴瘤激酶(anaplastic lymphoma kinase,ALK)、表皮生长因子受体(epidermal growth factor receptor,EGFR)及Kirsten鼠肉瘤基因(Kirstenrat sarcoma,KRAS)突变的阳性率及其与临床病理特征的关系.方法:采用免疫组织化学(immunohistochemistry,IHC)的方法检测ALK融合基因异常表达,采用PCR检测EGFR基因和KRAS基因突变,采用x2检验及Fisher精确概率法进行数据分析.结果:共2 267例进行了ALK融合基因检测,其中1 655例同时进行了EGFR突变检测,951例同时进行了KRAS检测.ALK融合基因、EGFR基因及KRAS基因突变阳性率分别为7.28％(165/2 267)、48.58％(804/1 655)、11.40％(108/947).ALK基因突变多见于年轻、腺癌患者;EGFR基因突变多见于女性、腺癌患者;KRAS基因突变多见于老年、男性、腺癌患者.1 655例同时进行了ALK与EGFR检测的病例中,共6例存在双基因突变(0.36％);947例同时进行了ALK与KRAS检测,共4例存在双基因突变(0.42％);943例同时进行了EGFR与KRAS突变检测,未发现双突变病例.结论:非小细胞肺癌患者ALK,EGFR和KRAS基因的突变与患者的年龄、性别、组织学类型均存在相应的联系,个别病例可以出现ALK融合基因与EGFR或KRAS突变共存.     

中国人非小细胞肺癌EGFR和K-RAS基因突变情况的研究

目的研究中国人非小细胞肺癌表皮生长因子受体(epidermal growth factor receptor,EGFR)基因和K-RAS基因突变情况。方法通过PCR扩增和基因测序的方法检测了101例中国人非小细胞肺癌(non-small cell lung cancers,NSCLCs)EGFR第18、19和21外显子及K-RAS密码子12、13的突变情况,并观察分析了其突变与肺癌临床特征及吉非替尼(gefitinib,商品名:易瑞沙/Iressa)药物治疗肺癌的疗效间的关系。结果共检测到26例EGFR突变(25.7%),3例K-RAS突变(2.9%),并发现腺癌患者、非吸烟患者和女性患者EGFR突变率较高(分别为44.2%、65.7%和48.3%)。10例服用吉非替尼有效的患者9例伴有EGFR突变。结论中国人肺癌的EGFR突变率高于西方人,吉非替尼疗效与EGFR突变有关。     

276例手术切除肺腺癌亚型与EGFR/ALK基因状态

目的:探讨手术切除肺腺癌各亚型EGFR和ALK基因状态分布.方法:应用ARMS方法检测手术切除肺腺癌石蜡组织中EGFR基因突变和ALK融合基因情况.结果:276例肺腺癌手术样本中,EGFR基因突变率为54.71％(151/276),其中19del为28.99％(80/276),L858R为23.19％(64/276),20-ins为0.72％(2/276),L861Q为0.72％(2/276),G719X为1.09％(3/276),S768I为0.36％(1/276)和T790M为0.72％(2/276),其中包含G719X+S768I,19del+T790M,L858R+T790M各1例,ALK基因融合阳性率为5.80％(12/207),在肺腺癌各亚型中EGFR基因突变附壁状腺癌,腺泡状腺癌,乳头状腺癌,实体状腺癌和浸润性黏液腺癌之间差异有统计学意义(P＜0.001,P=0.009,P=0.023,P＜0.001和P=0.030),与其他类型之间差异均无统计学意义(P＞0.05);在肺腺癌各亚型中ALK融合基因突变各亚型之间差异均无统计学意义(P＞0.05).结论:肺腺癌组织学亚型与EGFR基因突变有关,附壁状腺癌、腺泡状腺癌和乳头状腺癌出现EGFR基因突变比其他亚型更加明显.     

EGFR protein expression and gene amplification in squamous intraepithelial lesions and squamous cell carcinomas of the cervix

The purpose of this study was to evaluate the protein expression and gene amplification of epithelial growth factor receptor (EGFR) in intraepithelial neoplasias and squamous cell carcinoma of the cervix and to determine the value of EGFR in carcinogenesis, progression, and prognosis of cervical cancer. EGFR protein expression and gene amplification involved gene copy number in 75 cases of cervical various lesions were evaluated using immunohistochemistry and by fluorescence in situ hybridization (FISH) techniques. Expression of EGFR was observed in 76.00% of the high-grade CIN and 79.17% of the invasive carcinomas. In contrast, there were low levels of EGFR expression in chronic cervicitis (1/10) and low-grade CIN (7/16). There were statistically significant differences among them (P<0.05). Gene amplification was detected in 20.51% high-grade CIN and invasive carcinoma, but there only 4.35% EGFR gene amplification was observed in chronic cervicitis and low grade CIN. Among the 42 patients with negative or low levels of EGFR expression, 26 patients (61.90%) were found to have diploidy and 11 patients (26.20%) to have balanced triploidy. However, among the 20 patients with an intermediate and high levels of EGFR protein expression, 13 (65.00%) were found to have balanced polyploidy or gene amplification. All cases of EGFR gene amplification involved intermediate and high levels of protein expression. EGFR may be involved in the carcinogenesis of the cervix and may be an early event during the carcinogenesis. Overexpression of EGFR protein may result from gene amplification and increases in gene copy number.     

EGFR amplification and lack of activating mutations in metaplastic breast carcinomas

Metaplastic breast carcinomas are reported to harbour epidermal growth factor receptor (EGFR) overexpression in up to 80% of the cases, but EGFR gene amplification is the underlying genetic mechanism in around one-third of these. In this study, EGFR gene amplification as defined by chromogenic in situ hybridization and protein overexpression was examined in a cohort of 47 metaplastic breast carcinomas. Furthermore, the presence of activating EGFR mutations in exons 18, 19, 20, and 21 was investigated. Thirty-two cases showed EGFR overexpression and of these, 11 (34%) harboured EGFR gene amplification. In addition, EGFR amplification showed a statistically significant association with EGFR overexpression (p < 0.0094) and was restricted to carcinomas with homologous metaplasia. Ten cases, five with and five without EGFR amplification, were subjected to microarray-based CGH, which demonstrated that EGFR copy number gain may occur by amplification of a discrete genomic region or by gains of the short arm of chromosome 7 with a breakpoint near the EGFR gene locus, the minimal region of amplification mapping to EGFR, LANCL2, and SEC61G. No activating EGFR mutations were identified, suggesting that this is unlikely to be a common alternative underlying genetic mechanism for EGFR expression in metaplastic breast carcinomas. Given that metaplastic breast carcinomas are resistant to conventional chemotherapy or hormone therapy regimens and that tumours with EGFR amplification are reported to be sensitive to EGFR tyrosine kinase inhibitors, these findings indicate that further studies are warranted to explore EGFR tyrosine kinase inhibitors as potential therapeutic agents for metaplastic breast carcinomas harbouring amplification of 7p11.2.     

EGFR mutations in non-small-cell lung cancer among smokers and non-smokers: a meta-analysis

Mounting evidence has suggested somatic mutations in the EGFR gene are associated with better responsiveness to EGFR tyrosine kinase inhibitors (TKIs) in patients with non-small-cell lung cancer (NSCLC). Some, but not all, studies have reported that the mutations were more frequently observed in patients without a smoking history. To comprehensively address this issue, we performed a meta-analysis to evaluate the association between cigarette-smoking history and mutation of the EGFR gene in NSCLC. Twenty-six studies, involving 3,688 patients with NSCLC were included in the analysis. The pooled analysis shows that the incidence of EGFR mutations in NSCLC differs according to cigarette-smoking history. The odds ratio (OR) for the EGFR mutation in non-smokers relative to smokers was 4.829 (95% confidence interval [CI]: 3.598-6.482; P < 0.001). These data may assist clinicians in assessing the likelihood of EGFR mutations in patients with NSCLC when mutational analysis is not feasible.     

A change in CD3γ, CD3δ, CD3ϵ, and CD3ζ gene expression in T-lymphocytes from benzene-exposed and benzene-poisoned workers

Benzene is known to be highly toxic to a variety of cell types, including lymphocytes. A previous study showed that T-lymphocyte immune function disorder might be related to benzene exposure. To elucidate characteristics of TCR signal transduction in benzene-exposed workers, expression levels of CD3γ, CD3δ, CD3?, and CD3ζ genes in peripheral blood mononuclear cells (PBMC) were analyzed. Real-time RT-PCR using SYBR Green I was used to detect CD3 gene expression levels in PBMC from 20 benzene-exposed workers, seven workers with chronic mild benzene poisoning, five workers with chronic severe benzene poisoning and 14 healthy individuals (controls). The relative mRNA expression level was analyzed by the 2^?Δct?×?100% method. In benzene-exposed worker cells, significantly higher CD3δ, CD3?, and CD3ζ, expression levels were observed as compared with values for cells from the healthy controls. In the workers with chronic severe benzene poisoning, lymphocyte CD3γ, CD3?, and CD3ζ gene expression levels were significantly lower than in control cells. Lymphocytes from chronic mildly benzene- poisoned workers evinced two different gene expression patterns, i.e., CD3γ and CD3? levels were similar to those in the benzene-exposed worker cells, but CD3δ and CD3ζ expression levels were significantly lower relative to those in cells from chronic severely-benzene-poisoned counterparts. It remained to be determined if these reductions in expression of these genes presage or are indicative of deficiencies in the activities of T-lymphocytes in these workers. For now, it is hoped that this study may contribute to a better understanding of the disorders in cellular immunity frequently found with benzene-exposed workers.     

Mutations affecting BRAF, EGFR, PIK3CA, and KRAS are not associated with sporadic vestibular schwannomas

Sporadic vestibular schwannomas are benign tumors originating from the Schwann cells of the vestibular portion of the eigth cranial nerve. An important clinical hallmark of these tumors is their variable growth rate. Investigating vestibular schwannoma biology can help to clarify this variable growth rate and may offer targets for therapeutic treatment. A recent mutation analysis on sporadic non-head and neck schwannomas detected BRAF mutations in around 20 % of tumors. BRAF is part of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway. MAPK/ERK activation is associated with an uncontrolled cell growth. Mutated BRAF can function as a target to inhibit this pathway. Mutations in BRAF and other members of the MAPK/ERK pathway have not been investigated in sporadic vestibular schwannomas before. The goal of this study was to investigate if these mutations are present in vestibular schwannomas and whether these mutations correlate with tumor growth. Tumor specimens of 48 patients surgically treated for a sporadic vestibular schwannoma were analyzed. An allele-specific quantitative real-time PCR assay was performed to detect the 13 most frequent mutations affecting BRAF, EGFR, PIK3CA, and KRAS. Radiologically measured tumor growth was included in the analysis to identify potential relationships between these mutations and tumor progression. No activating hotspot mutations in BRAF, EGFR, PIK3CA, or KRAS were detected. The 13 most frequent mutations affecting BRAF, EGFR, PIK3CA, and KRAS are not involved in sporadic vestibular schwannoma development. These results are in contrast to the recent detection of these BRAF mutations in non-head and neck schwannomas.     

非小细胞肺癌患者肿瘤组织中EGFR和KARS基因突变的分子病理检测分析

目的：探讨非小细胞肺癌患者肿瘤组织中EGFR和KRAS基因各亚型突变情况。方法：应用直接测序方法检测非小细胞肺癌石蜡组织中1273例EGFR基因和1062例KRAS基因突变情况。结果：非小细胞肺癌肿瘤组织中EGFR基因总突变率为36.68%(467/1273),外显子18、19、20和21的突变率分别为1.02%(13/1273)、18.93%(241/1273)、2.59%(33/1273)和15.95%(203/1273);EGFR基因各外显子之间双重突变共17例(1.34%),其中18外显子与20外显子双重突变3例(0.24%),19外显子与20外显子双重突变7例(0.55%),19外显子与21外显子双重突变4例(0.31%)和20外显子与21外显子双重突变3例(0.24%);EGFR基因各外显子内双重突变共2例(2.18%),均为21外显子双重突变。KRAS基因总突变率为3.01%(32/1062),外显子2的密码子5、12、13和25的突变率分别为0.09%(1/1062)、2.64%(28/1062)、0.18%(2/1062)和0.09%(1/1062),外显子3密码子61的突变率为0.09%(1/1062)。结论：非小细胞肺癌患者中EGFR基因存在较高的突变率,尤其为19和21外显子突变,其基因突变亚型分类能指导EGFR-TKI的肿瘤靶向治疗,KRAS基因突变率虽低但不容忽视,其基因突变预示着EGFR-TKI原发耐药。     

HER2, TOP2A, CCND1, EGFR and C-MYC oncogene amplification in colorectal cancer

AIM: Recent studies had suggested substantial molecular differences between tumours from different ethnic groups. In this study, the molecular differences between the incidences of colorectal carcinoma in Saudi and Swiss populations are investigated. Method: 518 cases of colon cancer tumours (114 from Saudi Arabia and 404 from Switzerland) were analysed in a tissue microarray format. Fluorescence in situ hybridisation (FISH) was used to estimate frequencies of copy number changes of known oncogenes, including HER2, TOPO2A, CCND1, EGFR and C-MYC. RESULTS: Using FISH, amplifications were mostly low level (gene-to-centromere ratio 2 to 4), which is in contrast with other tumour types with more frequent gene amplifications. The amplifications were particularly frequent for MYC (Saudi 9% and Swiss 14.2%) but unrelated to clinical outcome and pathological information. Remarkably, there were four tumours exhibiting classic high-level gene amplification for HER2 (Swiss 1.3%), a pattern often accompanied by response to trastuzumab (Herceptin) in breast cancer. Occasional high-level amplifications were also observed for CCND1 (Saudi 1/106, 0.9%; Swiss 2/373, 0.5%) and EGFR (Swiss 2/355; 0.6%). CONCLUSIONS: Rare high-level amplifications of therapeutic target genes were found in patients with colon cancer. Although no molecular differences were found between incidences of colon cancer cases in Swiss and Saudi populations, these observations emphasise the urgent need for clinical studies investigating the effect of targeted therapies.     

Lack of association between the GNB3 rs5443, HIF1A rs11549465 polymorphisms,physiological and functional characteristics

The aim was to examine the association between the hypoxia-inducible factor-1α (HIF1A) gene and the guanine nucleotide binding protein beta polypeptide 3 (GNB3) gene polymorphisms and the endurance/power athlete status and relative aerobic capacity. Another goal of this study was to reveal the connection between GNB3, blood pressure (BP), body composition and body mass index (BMI). Two hundred thirty-eight people participated in this study: 148 elite athletes (men = 107, women = 41) and 90 controls (men = 51, women = 39). The athletes were divided into two groups: the power and the endurance athletes. BMI and body fat percentage (fat%) were calculated. Fifty of the athletes underwent an incremental treadmill test to exhaustion; BP was monitored before and after the test. There were differences in the genotype frequencies of HIF1A between the endurance and the control group (ProPro: 64% vs.79%, ProSer: 27% vs.19%, SerSer: 9% vs. 2%; p = .0351); in the allele prevalences among the three groups (Pro: 87% vs. 77% vs. 88%; Ser: 13% vs. 23% vs. 12%; p = .0103) and between the endurance and control group (p = .0049) as well. The GNB3 allele proportions differed in the three groups (C: 74% vs. 61% vs. 71%, T: 26% vs. 39% vs. 29%; p = .0436). There were no connections between the genotypes and the relative aerobic capacity and neither between GNB3 genotypes and BP, BMI and fat%. The connection of GNB3 T allele to the endurance performance still remained contradictable.     

Gene amplification of ERBB2 and EGFR in adenocarcinoma in situ and intramucosal adenocarcinoma of Barrett's esophagus

We examined 11 cases of carcinoma arising from Barrett's esophagus consisting of two adenocarcinomas in situ (ACIS), two intramucosal adenocarcinomas, and seven overt invasive adenocarcinomas. Overexpression of p53 (implying a mutation of the p53 gene), ERBB2, and EGFR was measured by immunohistochemistry, and gene amplification of ERBB2 and EGFR was measured by fluorescence in situ hybridization (FISH). In all cases of ACIS and the intramucosal adenocarcinomas, almost all cancer cells overexpressed p53, however the populations overexpressing ERBB2 and EGFR varied in different cases: in one ACIS, ERBB2 was coexpressed in all the cancer cells, in the other ACIS and one intramucosal adenocarcinoma, ERBB2 was overexpressed in about 50% and only 10% of the p53‐positive cells respectively. EGFR was co‐expressed in 20% in the other intramucosal adenocarcinoma. Protein overexpression of ERBB2 or EGFR corresponded to the amplification of their respective genes on a cell by cell basis. These gene amplifications, however, were not found in the seven invasive adenocarcinomas. Thus we speculate that the gene amplification occurred late in the dysplasia‐carcinoma sequence probably after the mutation of p53. Furthermore, new clonal expansion accompanied by tumor invasion might have extinguished the originally amplified genes in these tumors.