非小细胞肺癌患者血中DNA片段的检测、定量及临床意义的研究

目的探讨非小细胞肺癌患者血中游离DNA片段在临床上早期诊断、分期、预后方面的意义。方法随机采集2004年10月至12月大连医科大学附属二院经病理确诊的初治Ⅲ、Ⅳ期非小细胞肺癌患者的血标本15份,门诊健康体检者血标本15份,通过酚/氯仿提取法定量检测两组的血浆DNA片段,进行对照比较,分析非小细胞肺癌组内各因素(包括与诊断相关的肿瘤标记物,与预后相关的年龄、性别、一般状况及病理类型、疾病分期、免疫指标、是否转移等)与血浆游离DNA片段水平的相关性。结果非小细胞肺癌组血浆游离DNA片段水平高于正常健康对照组,其血浆游离DNA片段的均值分别为:(384.8±99.36)μg/ml与(13.9±3.60)μg/ml,差异有显著性,Ⅲ期与Ⅳ期非小细胞肺癌患者的血浆游离DNA片段差异有显著性,均值分别为:(290.4±91.82)μg/ml与(481.2±196.44)μg/ml,且非小细胞肺癌患者的血浆游离DNA片段与肿瘤标记物CA199、CYFRA21-1、ALP呈正相关性;在预后因素分析中,显示非小细胞肺癌患者的血浆游离DNA片段水平与一般状态、免疫状态、病理类型及是否存在远处转移等因素有明显相关性,其中与一般状态、免疫状态呈负相关,与远处转移呈正相关,与性别、年龄、治疗疗效等因素无相关性。结论非小细胞肺癌患者血中的游离DNA片段水平较健康人高,且不同病期有一定差异,可能与患者自身状态、病理分型、疾病状态有关;游离DNA片段可以作为检测非小细胞肺癌的特异性指标,还可以替代一般状态、免疫状态、病理类型、是否存在远处转移等指标评价远期预后,并有取材方便、检测时间短、可以定量分析的优点,对临床有一定的指导意义和应用价值。     

循环血液中游离DNA与胃肠道肿瘤的关系

胃肠道肿瘤是一类严重威胁人类健康的疾病.治疗上早期诊断是一个重要环节.人们一直在寻找一种简便无创的检测方法,对胃肠道肿瘤进行有效检测,并评价与肿瘤进展、分期、治疗效果几预后的关系.而临床上传统的肿瘤标志物在特异性上和敏感性上均不十分令人满意.血液中游离DNA的检测作为分子生物学研究的一个新兴领域,在肿瘤标志物检测方面给我们提供了新的手段.该文主要探讨了循环血液中游离DNA与胃肠道肿瘤的关系.     

血浆游离DNA检测在心血管系统疾病诊断中的应用

心血管疾病发病率和病死率居高不下,寻求敏感性高的生物学指标帮助早期诊断和改善预后意义重大.血浆游离DNA(cell-free DNA,cfDNA)是一类存在于血浆、尿液及其他体液中游离于细胞之外的双链DNA片段.血浆cfDNA水平在心血管疾病的早期明显升高,提示其可能是心血管疾病的潜在生物标志物.为了更深入理解cfDN...     

血浆游离DNA在临床应用中的新进展

血浆游离DNA(Plasma cell-free DNA,cf-DNA)是存在于人体血液中一种无细胞状态的胞外DNA。作为细胞死亡的标记物,近年来cf-DNA检测已用于多种急性或慢性疾病的诊断和预后评价中。虽然在健康人群的血浆中也可测量到一定量的cf-DNA,但据相关报道称在癌症,自身免疫性疾病,中风,败血症,先兆子痫和器官移植排斥中cf-DNA呈显著的高水平。本文对cf-DNA在临床工作中应用的新进展做出综述,观察其在肿瘤诊断,产前诊断,脓毒症及老年免疫衰老评估作用中的新进展,发现其相较其他生物标记物敏感性并无太大差别,但特异性更高,还可能与肿瘤的转移机制相关。对于老年个体衰老的机制尚未明确,炎症学说也尚未得到证实,如何评定衰老以及明确衰老的标记物已成为全世界研究的难点,而cf-DNA浓度可能代表了一种全身炎症反应和老年人死亡率新的生物标志物。这些研究都使得cf-DNA应用于临床工作中的前途更加光明。     

血浆游离DNA全基因组甲基化测序的实用稳定性评估

随着液体活检技术的发展,血浆游离DNA成为当前的研究热点之一。血浆游离DNA的全基因组甲基化测序被认为在癌症检测等医学应用拥有巨大潜力,但目前尚缺乏针对该实验流程的实用稳定性评估。文中利用两名志愿者在不同时间采样的血浆游离DNA,在不同实验平台分别进行DNA甲基化的重亚硫酸盐转化前建库(Pre-BS)、转化后建库(Post-BS)和常规DNA建库,获取多因素影响下的测序数据样本。在此基础上,建立了一套血浆游离DNA测序数据分析的质量控制参考流程,综合评估了血液采集提取、游离DNA建库测序过程的实用稳定性,为血浆游离DNA全基因组甲基化测序应用于临床液体活检提供实用性的基础参考。     

扩增子测序技术应用于乳腺癌循环游离DNA无创性检测的研究

目的:应用扩增子测序方法检测乳腺癌循环游离DNA肿瘤相关突变。方法:军事医学科学院附属医院的10例HER2阳性晚期乳腺癌患者血样入组,应用扩增子测序技术检测血细胞和血浆中的循环游离DNA(cfDNA),筛选出肿瘤相关基因突变,即循环肿瘤DNA(ctDNA)。结果:检测10例晚期乳腺癌患者外周循环血50个基因,共检出11个突变基因,其中PIK3CA、ERBB4的阳性检出率均达到100%,AKT、TP53的阳性检出率为90%。结论:检测覆盖度及深度均良好,结果提示11个基因的热点突变区域出现单核苷酸的多态性基因突变,突变基因与PI3K-AKT-m TOR通路、Ras-Raf-MEK-ERK通路明显相关。扩增子测序技术和筛选方法可以用于乳腺癌ctDNA的无创性检测。     

血浆循环游离DNA(cf DNA)联合癌胚抗原(CEA)在评估晚期非小细胞肺癌治疗疗效的临床价值

摘要 目的：研究血浆循环游离DNA（cf DNA）联合癌胚抗原（CEA）在评估晚期非小细胞肺癌（NSCLC）治疗疗效中的临床价值。方法：选取我院2019年1月~2022年1月收治的96例晚期NSCLC患者作为研究对象,所有患者均接受含铂双药化疗方案或放疗,评估治疗6个月后的临床疗效,根据疗效分为有效组与无效组,检测所有患者cf DNA及CEA水平并进行比较,单因素、多因素分析患者疗效的影响因素,并通过受试者工作特征曲线图（ROC）分析cf DNA及CEA对晚期NSCLC患者治疗疗效的评估价值。结果：本研究中96例患者均顺利完成化疗治疗,疗程结束后,有54例（56.25%）治疗有效,42例（43.75%）治疗无效;无效组肿瘤TNM分期Ⅳ期、体力状况（PS）评分2~4分占比大于有效组（P＜0.05）;无效组患者cf DNA及CEA水平明显高于有效组（P＜0.05）;多因素Logistic回归分析显示,肿瘤分期Ⅳ期、PS评分2~4分、cf DNA及CEA高水平均为影响晚期NSCLC患者疗效的相关因素（P＜0.05）;ROC曲线分析显示,cf DNA、CEA对晚期NSCLC患者治疗后无效均有预测效能（P＜0.05）,其中两指标联合预测的曲线下面积（AUC）最大,为0.794,特异度、敏感度分别为85.19%、78.57%。结论：治疗无效晚期非小细胞肺癌患者cf DNA及CEA水平更高,肿瘤分期Ⅳ期、PS评分2~4分、cf DNA及CEA高水平均为晚期NSCLC患者疗效的影响因素,联合cf DNA及CEA检测有利于对晚期NSCLC患者治疗疗效进行评估。     

小剂量FLP方案治疗晚期消化系肿瘤的胃肠道反应观察

以小剂量 FL P方案持续灌注治疗晚期消化系肿瘤 ,观察其胃肠道反应 ,与常规的以 5— FU为主的化疗方案相比较。结果表明小剂量 FL P方案组胃肠道反应低于常规化疗组 ,特别在重度胃肠道反应尤为明显 ,经统计差异有显著性 (P<0 .0 1)。提示小剂量 FL P方案胃肠道反应小 ,为晚期消化系肿瘤理想治疗方案。     

人体游离循环DNA的研究进展

游离循环DNA是一种细胞外游离状态的DNA, 在动植物及人的体液中都检测到了它的存在。对游离循环DNA的检测已经应用在疾病的监控、胎儿的产前诊断及肿瘤的研究中。文章介绍了循环DNA的生物学特征, 并对近年来游离循环DNA的研究和应用进展做了简单的回顾。     

血浆中游离核酸:分子诊断的新靶点

1948年Mandel和Metais首次报道在病人的血浆中有游离形式的核酸存在,当时并未引起人们的广泛关注,很长一段时间对于这些核酸的研究处于搁浅状态;如今,人们已经能够在血浆中检测得到肿瘤源﹑胎儿源以及移植物源的核酸,不仅可以将其应用于胎儿性别﹑RHD血型、Y染色体连锁的遗传疾病的诊断与预防,还可以应用这些游离形式的核酸检测肿瘤﹑癌症的发生以及骨髓移植后嵌合状态的研究。     

Association between hypermethylation of DNA repetitive elements in white blood cell DNA and early-onset colorectal cancer

Changes in the methylation levels of DNA from white blood cells (WBCs) are putatively associated with an elevated risk for several cancers. The aim of this study was to investigate the association between colorectal cancer (CRC) and the methylation status of three DNA repetitive elements in DNA from peripheral blood. WBC DNA from 539 CRC cases diagnosed before 60 years of age and 242 sex and age frequency-matched healthy controls from the Australasian Colorectal Cancer Family Registry were assessed for methylation across DNA repetitive elements Alu, LINE-1 and Sat2 using MethyLight. The percentage of methylated reference (PMR) of cases and controls was calculated for each marker. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression adjusted for potential confounders. CRC cases demonstrated a significantly higher median PMR for LINE-1 (p < 0.001), Sat2 (p < 0.001) and Alu repeats (p = 0.02) when compared with controls. For each of the DNA repetitive elements, individuals with PMR values in the highest quartile were significantly more likely to have CRC compared with those in the lowest quartile (LINE-1 OR = 2.34, 95%CI = 1.48–3.70; p < 0.001, Alu OR = 1.83, 95%CI = 1.17–2.86; p = 0.01, Sat2 OR = 1.72, 95%CI = 1.10–2.71; p = 0.02). When comparing the OR for the PMR of each marker across subgroups of CRC, only the Alu marker showed a significant difference in the 5-fluoruracil treated and nodal involvement subgroups (both p = 0.002). This association between increasing methylation levels of three DNA repetitive elements in WBC DNA and early-onset CRC is novel and may represent a potential epigenetic biomarker for early CRC detection.     

MAT2A与NDRG2基因在结直肠癌中表达情况及临床意义的研究

目的 研究MAT2A（甲硫氨酸腺苷转移酶2A）和NDRG2（N-Myc下游调节基因-2）基因在结直肠癌组织中的表达及两者的相关性,为结直肠癌的研究及治疗提供重要参考。方法 选取68例术中切除结直肠癌组织及相应的癌旁组织标本,应用RT-PCR（逆转录‒聚合酶链式反应）和Western blotting（蛋白质印迹法）检测结直肠癌中MAT2A和NDRG2表达水平。结果 结直肠癌中MAT2A和NDRG2 mRNA表达情况：MAT2A阳性表达率（66.2%,45/68）高于癌旁组织（7.4%,5/68）;NDRG2阳性表达率（36.8%,25/68）低于癌旁组织（91.2%,62/68）;两者的表达与患者年龄、性别、肿瘤生长位置等因素均无关,与癌肿临床分期、分化水平及淋巴结转移密切相关。癌肿组织中MAT2A蛋白表达量相较于癌旁组织明显增多（t=39.1152,P=0.0000）,而癌肿组织中NDRG2蛋白表达量较癌旁组织明显降低（t=46.5103,P=0.0000）;且在结直肠癌组织中两基因的表达可能有相关性（χ2=7.41,P=0.009）。结论 在结直肠癌组织中MAT2A表达增高,NDRG2表达低下,两者与肿瘤的发生发展具有一定相关性,推测可能与DNA甲基化异常有关,但具体机制仍待进一步研究。     

EGCG synergizes the therapeutic effect of irinotecan through enhanced DNA damage in human colorectal cancer cells

Irinotecan is a kind of alkaloid with antitumour activity, but its low solubility and high toxicity limit its application. Epigallocatechin-3-gallate (EGCG) is one of the main bioactive components in tea. The epidemiological investigation and animal and cell experiments show that EGCG has a preventive and therapeutic effect on many kinds of tumours. Here, colorectal cancer cells RKO and HCT116 were employed, and the CCK8 proliferation test was used to screen the appropriate concentration of EGCG and irinotecan, and the effects of single and/or combined drugs on migration, invasion, DNA damage, cell cycle and autophagy of tumour cells were investigated. The results showed that EGCG combined with irinotecan (0.5 μmol L⁻) not only had a stronger inhibitory effect on tumour cells than EGCG or irinotecan alone but also prevented tumour cell migration and invasion. EGCG alone did not cause DNA damage in colorectal cancer cells, but its combination with irinotecan could induce S or G2 phase arrest by inhibiting topoisomerase I to cause more extensive DNA damage. EGCG also induced apoptosis by promoting autophagy with irinotecan synergistically. These results indicated that EGCG in combination with irinotecan could be a promising strategy for colorectal cancer.     

Prognostic significance of EZH2 expression in patients with oesophageal cancer: a meta‐analysis

Enhancer of zeste 2 (EZH2), a key component of polycomb repressive complex 2 (PRC2), was of great importance in human cancer pathogenesis. Various studies examined the relationship between EZH2 overexpression with the clinical outcome in patients with digestive cancers, but yielded conflicting results. Electronic databases updated to January 2015 were searched to find relevant studies. A meta‐analysis was conducted with eligible studies which quantitatively evaluated the relationship between EZH2 overexpression and survival of patients with digestive cancers. Survival data were aggregated and quantitatively analysed. We performed a meta‐analysis of 10 studies (n = 1461 patients) that evaluated the correlation between EZH2 overexpression and survival in patients with digestive cancers. Combined hazard ratios suggested that EZH2 overexpression was associated with poor prognosis of overall survival (HR = 1.54, 95% CI: 1.27–1.81) in patients with oesophageal cancer. In the stratified analysis, no significant risks were found among gastric cancer (HR = 0.66, 95% CI: 0.16–1.15) and colorectal cancer (HR = 0.91, 0.63–1.19), indicating that EZH2 was not an indicator of poor prognosis in gastric cancer or colorectal cancer. Enhancer of zeste 2 overexpression indicates a poor prognosis for patients with oesophageal cancer, but not among gastric cancer or colorectal cancer.     

The potential role of regulatory microRNAs of RAS/MAPK signaling pathway in the pathogenesis of colorectal cancer

Colorectal cancer (CRC) is the leading cause of cancer death worldwide. Dysregulation of RAS/MAPK signaling axis is frequently found in CRC patients. The RAS/MAPK axis regulates cancer cell proliferation, apoptosis, inflammation, migration, and metastasis. Oncogenic or tumor-suppressor microRNAs (miRNAs) for RAS/MAPK signaling play a key role in the pathogenesis of CRC and are considered as novel potential biomarkers for diagnosis and prognosis of human malignancies. This review summarizes the current knowledge of mechanisms of action of RAS/MAPK miRNAs in the development and progression of CRC for a better understanding and hence a better management of this disease.