Quantitative analysis of plasma circulating DNA at diagnosis and during follow-up of breast cancer patients

The aim of the present project was to quantify the level of plasma DNA in patients with malignant or non-malignant breast diseases and in healthy controls, then investigate whether such measurements have diagnostic or prognostic value. Plasma DNA from 121 women (61 patients with breast cancer, 33 control patients with benign breast diseases and 27 healthy control individuals) was quantified by a real-time quantitative polymerase chain reaction (PCR) method. Plasma DNA concentration in the breast cancer patients (median 65 ng/ml) was significantly higher (P<0.05) than that in the control patients (median 22 ng/ml) or healthy control (median 13 ng/ml). No association was observed between plasma DNA levels and clinicopathological parameters. The data suggest that quantification of plasma circulating DNA may be a valuable complementary diagnostic tool in discriminate breast cancer from unaffected individuals and may be proposed as an early detection test as well as a new, noninvasive assay to follow-up patients.     

肺鳞癌、腺癌中p14 ARF基因启动子区甲基化及蛋白表达的研究

背景与目的 p14^ARF基因是新近发现的抑癌基因，其异常表达与多种人类肿瘤发生有关，启动子区异常甲基化作为p14^ARF基因失活的重要形式可能参与了肿瘤的发生。本研究通过检测肺鳞癌、腺癌中p14^ARF启动子区甲基化状态和蛋白表达，探讨p14^ARF启动子区甲基化与肺癌的关系。方法 通过免疫组织化学（IHC）、甲基化特异性PCR（MSP）和相关限制性内切酶PCR（RF-PCR）方法，检测40例肺鳞癌、腺癌组织中p14^ARF启动子区甲基化状态和蛋白表达水平。结果 癌组织及癌旁正常组织中p14^ARF启动子区甲基化阳性率分别为17．5％（7／40）和2．5％（1／40）（P-0．025）。RE-PCR检测结果相同。癌组织及癌旁正常组织中p14^ARF蛋白阳性率分别为70．0％（28／40）和95．0％（38／40）（P-0．003）。p14^ARF基因启动子区甲基化和蛋白表达均与肿瘤分期、组织类型、分化程度、淋巴结转移等临床病理特征无明显关系（P＜0．05）。p14^ARF启动子区甲基化与蛋白表达呈负相关（r=-0．56，P=0．001）。结论 启动子区甲基化是p14^ARF基因失活的重要机制。p14^ARF启动子区异常甲基化可能参与了非小细胞肺癌的发生，是肺癌发生过程的早期事件。     

非小细胞肺癌患者血清Ras相关区域家族1A基因启动子异常甲基化检测及其临床意义

目的 研究非小细胞肺癌(NSCLC)患者血清Ras相关区域家族1A(RASSF1A)基因启动子区域的甲基化状态及其临床意义.方法 采用甲基化特异性聚合酶链反应(MSP)技术,检测75例NSCLC患者血清RASSF1A基因启动子区域的甲基化状态,并分析其与临床病理参数之间的相关性.结果75例NSCLC患者血清RASSF1A基因启动子区域异常甲基化检出率为30.7%(23/75),而35例肺部良性疾病患者和15例健康志愿者中检出率均为0,差异有统计学意义(P＜0.001).RASSF1A启动子异常甲基化与NSCLC患者的年龄、性别、病理类型无显著相关性,但在晚期及肿瘤分化程度较低的患者中检出率较高(P＜0.05).结论 RASSF1A启动子异常甲基化在NSCLC的发生、发展中起重要作用,有望成为NSCLC辅助诊断和预后判断的分子标记.     

Ⅰ期非小细胞肺癌预后因素的研究

目的 探讨Ⅰ期非小细胞肺癌(NSCLC)的联合预后因素。方法 回顾性分析58例Ⅰ期NSCLC患者的临床资料、术后病理结果和免疫组化技术检测的9项基因表达指标(c-myc、MDM2、c-erbB-2、EGFR、p53、p14^ARF、p16^INK4、p21^WAF1、nm23)。观察患者的总生存率、局部区域性复发率和远处转移率。结果 全组5年生存率、局部区域性复发率和远处转移率分别为71．1％,11．1％和33．5％。单因素分析结果表明,肿瘤细胞的低分化是影响总生存率的不良预后因素(P=0.028);c—myc与c-erbB-2的高表达均为影响总生存率和远处转移率的不良预后因素;促进肿瘤增殖基因总分组的高分值(P=0．041)与综合肿瘤基因组的高分值(P=0．006),是总生存率的不良预后因素。多因素分析结果表明,肿瘤细胞的分化程度与综合肿瘤基因的联合表达,是影响总生存率的独立预后因素。本组结果还显示,已行化疗的高危组患者,其总生存率与无远处转移率均优于未行化疗者,但差异尚未见有显著性。结论 肿瘤细胞的分化程度与综合肿瘤基因的表达,可能是Ⅰ期NSCLC的预后因素。高危组患者进行术后化疗似有提高疗效的趋势。     

DNA甲基化在肺癌中的研究进展

肺癌是严重威胁人类生命健康的恶性肿瘤之一。DNA甲基化作为表观遗传学的主要组成部分,其在细胞增殖、凋亡、DNA修复、肿瘤侵袭和转移等生物过程中起着重要作用。大量研究证明,DNA甲基化在肺癌的发展中扮演着重要的角色,本文就近年来DNA甲基化在肺癌中的发病机制、诊断、治疗及预后的研究进展作一综述。     

HYPERMETHYLATION OF p14^ARF PROMOTER REGION AND EXPRESION OF p14^ARF GENE PRODUCT IN NON-SMALL CELL LUNG CANCER

Objective： This study was designed to investigate promoter methylation status and protein expression of p14^ARF gene in non-small cell lung cancer, and value the role of p14^ARF promoter methylation in carcinogenesis of non-small cell lung cancer. Methods： Promoter methylation status and protein expression of p14^ARF gene in 40 cases of non-small cell lung cancer were analyzed by methylation specific polymerase china reaction （MSP）, restriction enzyme-related polymerase chain reaction （RE-PCR） and immunohistochemistry （IHC）. Results： The positive rates of p14^ARF promoter methylation in tumor tissues and normal tissues adjacent to cancer were 17.5% （7/40） and 2.5% （1/40） respectively. There were statistically significant differences between them, P〈0.05. The results of RE-PCR were consistent with that of MSP. The expression rate of p14^ARF protein in tumor tissues was significantly lower than that in normal tissues adjacent to cancer, p〈0.01. Promoter methylation status and protein expression of p14^ARF gene in non-small cell lung cancer showed significantly an inverse correlation （r=-0.56, P〈0.01）, and both of them did not relate statistically with the clinicopathologic characteristics of patients such as histological classification, clinical stage, differentiation grade and lymph node involvement. Conclusion： Promoter methylation is a crucial mechanism of inactivation of p14^ARF gene. Promoter methylation of p14^ARF gene might he involved in carcinogenesis of non-small cell lung cancer, and is an early event in development process of non-small cell lung cancer. It might be used as a new target in gene treatments in the future.     

循环肿瘤DNA在晚期乳腺癌的临床应用进展

晚期乳腺癌是严重威胁全世界女性健康的第一大恶性肿瘤,目前以综合治疗为主,包括化疗、内分泌治疗和靶向治疗等。短期内复发、转移是限制临床疗效和导致患者预后差的重要因素,而影像学检查和传统血清标记物却难以及时有效地监测肿瘤的复发转移,导致临床治疗决策迟滞。因此,研发灵敏、准确、非／低侵入性的疗效监测方法 至关重要。循环肿瘤DNA（ctDNA）是游离于血浆中的来源于肿瘤细胞的坏死、凋亡和分泌过程的DNA。多项研究证实检测ctDNA突变水平变化对于恶性肿瘤早期诊断、用药指导、复发监测有着巨大的应用潜力。本文将对ctDNA监测晚期乳腺癌的临床应用研究进展综述如下。     

晚期肺癌血清游离DNA中EGFR外显子19的基因突变研究

目的分析晚期肺癌的上皮生长因子受体(epidermal growth factor receptor,EGFR)外显子19基因突变的类型及发生率。方法从血清中提取游离DNA进行EGFR外显子19特异性PCR扩增和基因测序。结果24例肺部良性疾病血样中EGFR基因外显子19均为野生型;而130例肺癌血样中检出突变55例,EGFR外显子19基因突变的检出率为42.3%。外显子19基因突变均为第746~752位密码子的碱基缺失,共有7种突变类型。外显子19基因突变主要见于肺腺癌及小细胞肺癌,其检出率分别为58.9%和57.1%,突变与患者年龄及性别无明显相关性。在肺癌的不同组织类型中,外显子19的突变形式存在显著差异,肺腺癌的基因突变谱与肺鳞癌、腺鳞癌及小细胞肺癌明显不同。结论晚期肺癌病人的血清游离DNA中存在EGFR基因突变,这类突变可以通过适当的方法检测出来,这种血液检测方法在晚期肺癌的EGFR基因诊断及靶向治疗中具有广泛的应用价值。     

循环肿瘤细胞的检测方法及其在肺癌临床中的应用

循环肿瘤细胞（CTCs）作为研究肺癌转移过程的一个切入点正越来越引起人们的兴趣。十九世纪末关于肿瘤转移提出的“种子-土壤”学说已经预测了CTCs的存在。但是,近年来才建立了可靠的、重复性好的检测和分析CTCs的实验方法。目前,CellSearch检测法已被广泛应用于临床,并获得了美国FDA的认证。CTCs计数可以用于指导对转移性肿瘤患者的预后评估,并且能够反映抗肿瘤药物的疗效,还可以监测肿瘤的复发。对CTCs的分子及遗传学特征的分析使其有可能被视为是一种非侵入性的“液基活检”,它能反映原发肿瘤组织的分子生物学及遗传学特征。本文就CTCs的生物学特征、在肿瘤转移过程中的作用、目前最常用的检测方法以及该方法在肺癌临床中的应用价值展开综述。     

Role of circulating free DNA in colorectal cancer

The gradual elucidation of the underlying biology of colorectal cancer has provided new insights and therapeutic options for patients with metastatic disease which are selected according to predictive biomarkers. This precision medicine paradigm, however, is incomplete since not all eligible patients respond to these agents and prognostic stratification is largely based on clinicopathologic variants. Importantly, no robust data exist to help properly select patients with localized disease at high risk for recurrence and most likely to benefit from adjuvant chemotherapy. There is a rapidly expanding body of literature regarding the role of the qualitative and quantitative analysis of circulating free DNA in various neoplasms, which consistently outperforms traditional tumor markers both as a predictive and as a prognostic marker. Several lines of evidence suggest that circulating free DNA may exhibit a complementary role to existing modalities for the early diagnosis of colorectal cancer, the selection of patients for adjuvant chemotherapy, for the follow-up of treated patients, for the selection of treatment for advanced disease and the assessment of response and for determining the prognosis of patients. These data, which are reviewed here, illustrate the important role that circulating biomarkers may soon have at the daily clinical practice.     

循环microRNA在肺癌研究中的进展

microRNA（miRNA）在肺癌的发生、发展中发挥着重要的调控作用。循环miRNA的发现，为肺癌诊断、治疗及预后判断提供了一种潜在的非侵入性生物标志。本文结合国内外最新报道对循环miRNA在肺癌诊断、预后判断及铂类化疗敏感性预测等方面的研究进展作一综述。     

循环DNA在大肠癌中的应用

循环DNA是一种存在于血浆、脑脊液及滑液等体液中的细胞外DNA.肿瘤患者循环DNA的含量明显高于健康人群,并具有与肿瘤发生、发展相关的特征性改变,例如基因突变、DNA甲基化、微卫星不稳定性等.循环DNA的定量与定性检测,在肿瘤的筛查、诊断、病情的监测以及预后评价中均有潜在的价值.     

肿瘤患者循环DNA的定量研究

目的建立纳克水平DNA定量方法,并探讨循环DNA检测在肿瘤诊断中的应用价值。方法对483例恶性肿瘤患者以微量基因组抽提试剂盒抽提血清DNA,以SYBRgreenⅠ荧光染色法行DNA定量;BRCA1(D17S579、D17S855)和p53(TP53,D17S786)微卫星位点的杂合性丢失检测采用聚合酶链反应结合聚丙烯酰胺凝胶电泳和银染的方法进行。同时与150例健康人血清的检测结果进行对照。结果SYBRgreenⅠ荧光染色可精确定量2～10ngDNA。483例恶性肿瘤患者血清DNA平均水平为(81.3±98.3)ng/ml,150例健康人血清DNA平均水平为(22.2±13.4)ng/ml,两者间差异有显著性(P<0.001);50例良性肿瘤患者血清DNA未见显著升高。在33例血清DNA含量增高的卵巢癌患者中,27例(81.8%)能测及BRCA1和p53微卫星标记中至少1个位点的杂合性丢失。结论循环DNA的定量有可能成为一种新的恶性肿瘤标志物。     

循环肿瘤DNA检测在乳腺癌诊断中的临床应用

随着二代测序技术的发展,循环肿瘤DNA(circulating tumor DNA,ctDNA)检测在乳腺癌中的应用得到越来越多的关注。目前国内外大量研究显示ctDNA检测技术在监测肿瘤负荷、疗效预测、早期诊断、预后分析等方面具有广阔的应用价值。在乳腺癌诊疗走向个体化精准的时代,ctDNA检测能够为患者提供更为精准的诊断,指导临床治疗。     

非小细胞肺癌ＳＦＲＰ１基因甲基化的研究

目的　检测ＳＦＲＰ１基因在非小细胞肺癌（ＮＳＣＬＣ）组织和血浆中的甲基化状态,分析其临床意义。方法　留取７８例ＮＳＣＬＣ患者术中癌组织、正常肺组织及术前血浆标本,２５例肺部良性病变组织及５０例肺部良性病变患者或健康志愿者血浆标本为对照,甲基化特异性聚合酶链反应（ＭＳＰ）检测ＳＦＲＰ１基因启动子区甲基化情况,并分析与临床病理特征之间的相关性。结果　７８例ＮＳＣＬＣ组织中,ＳＦＲＰ１基因启动子甲基化比例为３２.１％,高于正常组织的７.７％和２５例肺部良性病变组织的０（Ｐ＜０.０１）;ＳＦＲＰ１基因启动子甲基化与患者淋巴结转移相关（Ｐ＝０.０３９）。ＮＳＣＬＣ术前血浆ＤＮＡ中ＳＦＲＰ１甲基化比例为２８.２％,高于对照组的４.０％（Ｐ＜０.０１）,且血浆ＤＮＡ甲基化状况与组织中具有良好的一致性。结论　血浆ＤＮＡ中ＳＦＲＰ１甲基化检测可能对ＮＳＣＬＣ早期诊断有益。     

抑癌基因PTEN、PI3K、AKT在肺癌中的表达及临床意义

目的：探讨抑癌基因PTEN、PI3K、AKT在肺癌中的表达及临床病理学意义研究。方法采用免疫组化SP法检测PTEN、PI3K和AKT蛋白在62例肺癌组织和30例癌旁肺组织中的表达情况,并分析两者的相关性及与临床病理特征的关系,探讨其在肺癌中的作用机制。结果 PTEN mRNA在肺癌组织中表达明显低于癌旁组织,但PI3K mRNA和AKT mRNA在肺癌组织中表达则高于癌旁组织,差异均有统计学意义（P＜0．05）。 PTEN在肺癌组织中的阳性表达率为48．39％（30/62）,明显低于癌旁组织,而PI3K和AKT在肺癌组织中的阳性表达率分别为79．03％（49/62）和70．97％（44/62）,明显高于癌旁组织,差异具有统计学意义（ P＜0．01）。 PTEN、PI3K表达与肺癌的分化程度、TNM分期、淋巴结转移及病理类型相关,而AKT表达与肺癌的TNM分期、淋巴结转移及病理类型相关（ P＜0．05）。 PI3K与AKT表达呈正相关（P＜0．05）,与PTEN表达呈负相关（P＜0．05）,AKT与PTEN表达呈负相关（P＜0．05）。结论抑癌基因PTEN在肺癌中的低表达和PI3K/AKT的高表达,提示了PTEN、PI3K及AKT可能促进了肺癌的发生、发展及转移,而PI3 K/AKT细胞信号通路在此过程中起重要作用,可为肺癌的基因靶向治疗提供一个新的方向。     

肺癌循环肿瘤细胞的临床意义

转移是导致肺癌患者死亡的首因,而循环肿瘤细胞（Circulating tumor cells,CTCs）在形成远处转移过程中起关键作用。近年研究显示,CTCs可能成为肺癌诊疗的新兴标志物及治疗新靶点,本文从诊断与临床分期、转移与复发、个体化治疗与预后等方面阐述肺癌CTCs的临床意义,以期为肺癌治疗提供新策略。     

DNA hypermethylation in breast cancer and its association with clinicopathological features

Aberrant hypermethylation of gene promoter regions is one of the mechanisms for inactivation of tumour suppressor genes in breast cancer. We investigated whether hypermethylation identifies breast cancers with distinctive clinical and pathological features. We evaluated the methylation of RARβ2, CDH1, ER, BRCA1, CCND2, p16 and TWIST in 193 breast carcinomas. Methylation frequencies ranged from 11% for CCND2 to 84% for ER. Tumours with frequent methylation (4–6 genes) were more often poorly differentiated compared to those with infrequent methylation (0–2 genes; P=0.004). Tumours with ER and CDH1 methylation were associated with significantly lower hormone receptor levels, younger age at diagnosis and the presence of mutant p53. Our data suggests that gene methylation may be linked to various pathological features of breast cancer, however, this requires confirmation in larger studies.     

循环肿瘤细胞在肺癌中的研究

循环肿瘤细胞(CTC)是存在于外周血中的肿瘤细胞,在肺癌复发及转移过程中有重要作用.随着目前对CTC的研究及靶向治疗的不断深入,发现CTC可作为一种“液态”肿瘤组织指导临床治疗,对肺癌临床分期有一定指导意义,并对预后判断具有重要价值.     

The presence of circulating total DNA and methylated genes is associated with circulating tumour cells in blood from breast cancer patients

Circulating tumour cells (CTC) and tumour-related methylated DNA in blood have been separately assessed for their utility as a marker for subclinical metastasis in breast cancer. However, no studies have looked into the relation between the both molecular markers in this type of cancer. In this study, we investigated the correlations between total/methylated DNA and CTC in the blood from metastatic breast cancer patients. We simultaneously obtained whole blood, plasma and serum samples from 80 patients and 20 controls. The CellSearch System was used to enumerate CTC in blood samples. Plasma total DNA levels were determined by a QPCR method. Sera were analysed by methylation-specific QPCR for three markers: adenomatous polyposis coli (APC), ras association domain family protein 1A (RASSF1A) and oestrogen receptor 1 (ESR1). Total DNA levels in patients were significantly increased when compared with controls (P<0.001) and correlated with the number of CTC (r=0.418, P<0.001). Hypermethylation of one or more genes was detected in 42 (53%) serum samples from breast cancer patients and in three (16%) serum samples from controls (P=0.003). APC was hypermethylated in 29%, RASSF1A in 35% and ESR1 in 20% of breast cancer cases. Detection of a methylated gene in serum was associated with the detection of CTC in blood (P=0.03). The detection of large amounts of circulating total/methylated DNA correlated with the presence of CTC in the blood from patients with breast cancer. This can be interpreted in two ways: (a) CTC are a potential source of circulating tumour-specific DNA; (b) high numbers of CTC and circulating methylated DNA are both a phenotypic feature of more aggressive tumour biology.