非编码RNA在肿瘤液体活检中的研究进展

液体活检是一种基于分析体液样本中的生物标志物来诊断疾病、监测疾病进展和评估疗效的非侵入性的新型微创诊断技术。液体活检主要包括探查和检测循环肿瘤细胞、ctDNA、非编码RNAs和细胞外囊泡等。非编码RNA之前被认为是一类无功能的RNA,但近年来研究表明它们在肿瘤的发病机制中扮演着重要的角色。它们构成了基因调控的一个重要层面,其表达水平在多种癌种中呈现失调势态,这提示了它们作为肿瘤生物学标志物的临床应用潜力。飞速发展的高通量测序技术使得在泛癌领域建立非编码RNA表达谱的分子表征成为可能。该文系统阐述了非编码RNA作为非侵入性肿瘤标志物的研究进展,评估了其作为肿瘤生物标志物的适用性,同时总结了近期的检测技术突破对肿瘤分子标志物发展的影响。     

基于16S rRNA和非靶向代谢组测序分析结直肠癌患者肠道菌群及代谢物的变化

目的 采用16S rRNA和非靶向代谢组测序分析的方法探讨结直肠癌患者肠道菌群和其代谢产物的变化。方法 新鲜粪便为实验样品,收集10个结直肠癌患者组样本和6个正常对照组样本进行16S rRNA测序,分析肠道菌群的组成、多样性和物种差异,并对预测差异肠道菌群代谢功能;取8个结直肠癌组样本和6个正常对照组样本进行LC-MS非靶向代谢组学测序,分析代谢产物变化情况并进行功能预测。结果 结直肠癌组的菌群多样性较正常对照组无显著差异（P>0.05）。结直肠癌组的优势菌群为疣微菌门,结直肠癌组葡萄球菌、嗜冷杆菌属、毛螺菌科NK4A136、梭状芽孢杆菌vadinBB60和CAG-56相对丰度增加（P<0.05）,CAG-352、瘤胃球菌属、粪球菌属和挑剔真杆菌相对丰度降低（P<0.05）。KEGG富集分析发现,差异菌群在环境信息处理、遗传信息处理和新陈代谢等通路中发挥重要作用。非靶向代谢组学测序检测出两组样本有367种代谢物存在显著差异,对差异代谢物进行功能预测发现与咖啡因、嘌呤、氨基糖和核苷酸糖和生物素等的代谢相关。结论 结直肠癌患者的肠道菌群和代谢物与健康个体存在差异,结直肠癌...     

阿尔茨海默症生物标志物在脑脊液和血液中的研究

阿尔茨海默症(Alzheimer's disease, AD)是一种常见的神经退行性疾病。因为疾病本身很难被治愈,因此早期预测诊断对AD的防治尤为重要。目前,痴呆前期AD的主要诊断方法是脑脊液生物标志物的检测和正电子发射式计算机断层扫描(PET),但是这两种诊断方法侵入性强,价格昂贵,不容易普及。而对血液中的AD相关标志物进行检测,可以使AD的诊断更为普及且更为方便。该文总结了目前AD主要的几种生物标志物,概述了它们在AD患者和正常个体脑脊液和血液中的变化,最后也讨论和分析了未来AD生物标志物在血液检测中可能遇到的挑战。     

用纳米传感器诊断早期肺癌的研究进展

肺癌是世界范围内造成死亡的恶性肿瘤之一。早期识别不仅有助于检测原发癌,而且能监测肿瘤发展进程以评估风险。目前可用的诊断方法昂贵或具有侵入性,并不适于普遍筛查。非侵入性诊断技术用于监测癌症的发展仍是一个难题。基于呼气生物标志物的挥发性化合物(VOC)可用于分析患者的呼吸。本文回顾了各种VOC分析方法,包括使用最新的金纳米粒子检测VOC。该技术适于早期发现肺癌,高度准确,相对容易操作,显示出作为一种非侵入性和具有成本效益的诊断技术的巨大潜力。     

环状RNA的功能及其在结直肠癌中的作用

环状RNA(circular RNA, circRNA)是一类普遍存在于生物体内的闭合环状非编码RNA,能够抵抗核酸外切酶的水解作用,参与基因的表达调控过程。结直肠癌(colorectal cancer, CRC)是一类常见的恶性肿瘤,其全球发病率和死亡率居所有肿瘤前位,目前亟需一种有效的筛查手段。circRNA参与多种疾病(包括肿瘤)的发生发展,有望成为肿瘤早期筛查与诊断的生物标志物以及判断预后的指标,同时成为治疗肿瘤新的靶点。本文简要综述了环状RNA的形成和生物学功能,以及在结直肠癌中的研究进展,旨在为结直肠癌的早期诊断和治疗提供参考。     

乳腺癌早期筛查和诊断生物标志物研究进展

2020年全球乳腺癌(breast cancer,BC)新发病例达226万例,占全部肿瘤新发病例的11.7%,是全世界发病率最高的癌症。早期发现、早期诊断和早期治疗是降低乳腺癌死亡率及改善预后的关键。尽管乳房X光筛查被广泛用作乳腺癌筛查的工具,但其假阳性、辐射性和过度诊断仍是亟待解决的问题。因此,亟需开发易于获取且稳定可靠的生物标志物,用于乳腺癌无创筛查和诊断。近年来多项研究显示来自乳腺癌患者血液中的循环肿瘤细胞DNA(circulating tumor cell DNA,ctDNA)、癌胚抗原(carcinoembryonic antigen,CEA)、糖类抗原15-3(carbohydrate antigen 15-3,CA15-3)、细胞外囊泡(extracellular vesicles,EV)、循环miRNA和BRCA基因突变等生物标志物,以及来自人体尿液、呼出气体(volatile organic compounds,VOCs)和乳头吸出液(nipple aspirate fluid,NAF)中的磷脂、miRNA、苯乙酮和十六烷等多种生物标志物与乳腺癌早期筛查和诊断密切相关。本文综述了上述生物标志物在乳腺癌早期筛查和诊断中的应用。     

冠心病相关循环miRNA

冠心病诊断中最主要的挑战就是从常规的血液样本中鉴定出可靠的临床生物标志物.循环miRNA是一种可以稳定存在于体液中的小分子RNA,具有较高的组织、疾病特异性及敏感性,具有作为新的冠心病非侵入性生物标志物的潜力.通过综述血液样本（全血、血浆、血清、外周血单核细胞（PBMC）、内皮祖细胞（EPC）及血小板）中冠心病相关循环miRNA,及探讨循环miRNA研究中存在的一些问题,为未来筛选出真正具有临床应用价值的循环miRNA生物标志物奠定基础.     

外泌体在结直肠癌肝转移中的研究进展

肝脏是结直肠癌最常见的转移部位之一,肝转移灶的发生和发展会直接导致结直肠癌患者生存期明显缩短,且现有的治疗策略总体效果欠佳,因此,寻找更为有效的诊断和预后的生物标志物及可干预的靶点成为改善结直肠癌患者预后的一项重要任务。外泌体在结直肠癌肝转移过程中起重要作用,可介导化疗耐药的产生,同时作为生物标志物在结直肠癌肝转移的诊断和预后方面也具有一定价值。外泌体研究为结直肠癌靶向治疗提供了分子基础。本文就外泌体在影响结直肠癌肝转移、促进治疗耐药以及为结直肠癌肝转移提供诊断及预后价值的研究进展进行综述。     

循环长链非编码RNA作为生物标志物在肿瘤分子诊断中的应用

长链非编码RNA(Long noncoding RNA,lncRNA)被发现广泛参与基因表达、表观遗传调控和X染色体失活等重要生命过程,还与肿瘤发生和发展密切相关。lncRNA可能以微泡、外泌体或蛋白质复合物形式进入人体循环系统中,形成循环lncRNA稳定而广泛存在于血液、尿液等体液中。文中简要回顾了近来关于循环lncRNA的来源,以及作为生物标志物的检测方法,着重总结分析了循环lncRNA作为潜在肿瘤生物标志物在肺癌、乳腺癌、胃癌、肝癌、结直肠癌和前列腺癌等常见恶性肿瘤中的早期诊断价值。与传统生物标志物相比,循环lncRNA具有作为新型生物标志物的独特优势和临床应用价值。     

粪便留取量对粪便中细菌结构和功能的影响CSCD

目的探究不同粪便留取量对肠道菌群构成研究结果的影响,为肠道菌群构成研究中粪便样本的采集方式提供参考。方法本研究分别对全便和部分粪便进行预处理,并使用PacBio SMRT测序技术对10名志愿者的20份粪便样本进行了16S rRNA全长测序,通过多元统计学等手段对粪便中细菌的构成、多样性和功能进行比较分析。结果Eubacterium rectale、Eubacterium ventriosum和Allisonella histaminiformans等低丰度物种的相对丰度在不同粪便留取量中有一定差异,其在全便中的相对丰度均显著高于部分粪便(P<0.05)。但Wilcoxon配对检验发现粪便留取量对肠道菌群结构、多样性和功能的影响均无显著性差异(P>0.05)。不同个体间肠道菌群结构存在明显差异,且粪便留取量的影响远小于个体差异。结论全便和部分粪便两种粪便留取量对检测微生物的组成、多样性和功能无显著影响,因此取部分粪便即可满足对肠道菌群研究的要求。     

Identifying potential DNA methylation markers in early-stage colorectal Cancer

Colorectal cancer (CRC) is the second leading malignancy worldwide. Accurate screening is pivotal to early CRC detection, yet current screening modality involves invasive colonoscopy while non-invasive FIT tests have limited sensitivity. We applied a DNA methylation assay to identify biomarkers for early-stage CRC detection, risk stratification and precancerous lesion screening at tissue level. A model of biomarkers SFMBT2, ITGA4, THBD and ZNF304 showed 96.1% sensitivity and 87.0% specificity in CRC detection, with 100.0% sensitivity for advanced precancerous lesion and stage I CRC. Performances were further validated with TCGA data set, which showed a consistent AUC of 0.99 and exhibited specificity against other cancer types. KCNJ12, VAV3-AS1 and EVC were further identified for stage stratification (stage 0-I versus stage II-IV), with AUC of 0.87, 83.0% sensitivity and 71.2% specificity. Additionally, dual markers of NEUROD1 and FAM72C showed 83.2% sensitivity and 77.4% specificity in differing non-advanced precancerous lesions from inflammatory bowel diseases.     

Blood-Based Protein Biomarker Panel for the Detection of Colorectal Cancer

Background

The majority of colorectal cancer (CRC) cases are preventable by early detection and removal of precancerous polyps. Even though CRC is the second most common internal cancer in Australia, only 30 per cent of the population considered to have risk factors participate in stool-based test screening programs. Evidence indicates a robust, blood-based, diagnostic assay would increase screening compliance. A number of potential diagnostic blood-based protein biomarkers for CRC have been reported, but all lack sensitivity or specificity for use as a stand-alone diagnostic. The aim of this study was to identify and validate a panel of protein-based biomarkers in independent cohorts that could be translated to a reliable, non-invasive blood-based screening test.

Principal Findings

In two independent cohorts (n = 145 and n = 197), we evaluated seven single biomarkers in serum of CRC patients and age/gender matched controls that showed a significant difference between controls and CRC, but individually lack the sensitivity for diagnostic application. Using logistic regression strategies, we identified a panel of three biomarkers that discriminated between controls and CRC with 73% sensitivity at 95% specificity, when applied to either of the two cohorts. This panel comprised of Insulin like growth factor binding protein 2 (IGFBP2), Dickkopf-3 (DKK3), and Pyruvate kinase M2(PKM2).

Conclusions

Due to the heterogeneous nature of CRC, a single biomarker is unlikely to have sufficient sensitivity or specificity for use as a stand-alone diagnostic screening test and a panel of markers may be more effective. We have identified a 3 biomarker panel that has higher sensitivity and specificity for early stage (Stage I and -II) disease than the faecal occult blood test, raising the possibility for its use as a non-invasive blood diagnostic or screening test.     

Colonoscopic surveillance of first-degree relatives of colorectal cancer patients in a faecal occult blood screening programme

Background: In some Italian areas, colonoscopic surveillance of first-degree relatives (FDRs) of colorectal cancer (CRC) patients is provided as a part of local population-based faecal occult blood test (FOBT) screening programmes. The objective of the present study was to assess the feasibility and early results of this surveillance model. Methods: Data from district screening centres were used to evaluate the process of identification and selection of eligible FDRs (residence in the Emilia-Romagna Region, age 40–75 years, no recent colonoscopy) of screen-detected CRC patients and the detected prevalence of disease. The probability for an FDR to undergo colonoscopy and to be diagnosed with CRC and advanced adenoma was estimated using the Kaplan–Meier method. The sex- and age-standardised ratio of detected prevalence to that expected based on results from a colonoscopy screening study of the Italian general population was estimated. Results: Between 2005 and 2011, 9319 FDRs of 2437 screen-detected CRC patients (3.8 per patient) were identified and contacted. Their likelihood of being eligible for, and accepting, colonoscopy was 0.11 (95% confidence interval: 0.11–0.12). Among the 926 subjects undergoing colonoscopy, the prevalence of previous negative screening FOBT was 63%. Eleven CRCs (1.2%) and 100 advanced adenomas (10.8%) were detected. The standardised ratio of detected prevalence to that expected was 0.91 (95% confidence interval: 0.19–2.66) for CRC and 1.48 (1.04–2.05) for advanced adenoma. Conclusions: The procedure of selection of FDRs was extremely ineffective. Due to previous negative screening tests, the prevalence of disease was less than expected. A population-based FOBT screening programme is a highly unsuitable setting for the provision of surveillance to FDRs of CRC patients.     

Noninvasive molecular biomarkers for the detection of colorectal cancer

Colorectal cancer (CRC) is the third most common malignancy in the world. Because CRC develops slowly from removable precancerous lesions, detection of the disease at an early stage during regular health examinations can reduce both the incidence and mortality of the disease. Although sigmoidoscopy offers significant improvements in the detection rate of CRC, its diagnostic value is limited by its high costs and inconvenience. Therefore, there is a compelling need for the identification of noninvasive biomarkers that can enable earlier detection of CRC. Accordingly, many validation studies have been conducted to evaluate genetic, epigenetic or protein markers that can be detected in the stool or in serum. Currently, the fecal-occult blood test is the most widely used method of screening for CRC. However, advances in genomics and proteomics combined with developments in other relevant fields will lead to the discovery of novel non invasive biomarkers whose usefulness will be tested in larger validation studies. Here, noninvasive molecular biomarkers that are currently used in clinical settings and have the potential for use as CRC biomarkers are discussed.     

Evaluation of a colorectal cancer screening program composed of successive waves of different tests: The experience of the French Calvados County

BackgroundsThe value of colorectal cancer (CRC) screening program in a population with a limited participation rate is debated. This study assesses the real-life performances of different screening tests in a population benefiting from an organized program and included in a cancer registry.MethodsPatients who participated in at least one screening campaign between 2004 and 2016 were included. Four screening procedures were used: Hemoccult II, Magstream, Hemoccult and Magstream combined, and OC Sensor. Data were crossed with the Digestive Cancer Registry of Calvados to detect CRCs diagnosed during this period. The main outcomes were CRC detection and the incidence rate of interval cancers.ResultsScreening consisted of 325,083 tests in 134,498 patients. Of the 2580 CRCs detected in patients aged 50–74, 534 (20.7 %) were screen-detected. OC Sensor had the highest sensitivity for CRC detection (83.7 %, 95 % CI [76.8–89.1 %]) and the lowest interval cancer rate (2.0 per 10,000 person-years, 95 % CI [1.4–2.7]) compared with other screening tests, excluding combinations. The overall participation rate was 28.9 %.ConclusionReal-life differences in performance between different screening tests exist, and OC Sensor appears to be the best. The low participation rate suggests that the rate of screen-detected CRC could be higher.     

Colorectal cancer risk factors in the detection of advanced adenoma and colorectal cancer

Several risk factors for colorectal cancer (CRC) have been identified. If individuals with risk factors are more likely to harbor cancer or it precursors screening programs should be targeted toward this population. We evaluated the predictive value of colorectal cancer risk factors for the detection of advanced colorectal adenoma in a population based CRC colonoscopy screening program. Data were collected in a multicenter trial conducted in the Netherlands, in which 6600 asymptomatic men and women between 50 and 75 years were randomly selected from a population registry. They were invited to undergo a screening colonoscopy. Based on a review of the literature CRC risk factors were selected. Information on risk factors was obtained from screening attendees through a questionnaire. For each CRC risk factor, we estimated its odds ratio (OR) relative to the presence of advanced neoplasia as detected at colonoscopy. Of the 1426 screening participants who underwent a colonoscopy, 1236 (86%) completed the risk questionnaire. 110 participants (8.9%) had advanced neoplasia. The following risk factors were significantly associated with advanced neoplasia detected by colonoscopy: age (OR: 1.06 per year; 95% CI: 1.03–1.10), calcium intake (OR: 0.99 per mg; 95% CI: 0.99–1.00), positive CRC family history (OR: 1.55 per first degree family member; 95%CI: 1.11–2.16) and smoking (OR: 1.75; 95%CI: 1.09–2.82). Elderly screening participants, participants with lower calcium intake, a CRC family history, and smokers are at increased risk of harboring detectable advanced colorectal neoplasia at screening colonoscopy.     

Detection of cadherin-17 in human colon cancer LIM1215 cell secretome and tumour xenograft-derived interstitial fluid and plasma

Colorectal cancer (CRC), one of the most prevalent cancers in the western world, is treatable if detected early. However, 70% of CRC is detected at an advanced stage. This is largely due to the inadequacy of current faecal occult blood screening testing and costs involved in conducting population-based colonoscopy, the ‘gold standard’ for CRC detection. Another biomarker for CRC, carcinoembryonic antigen, while useful for monitoring CRC recurrence, is ineffective, lacking the specificity required early detection of CRC. For these reasons there is a need for more effective blood-based markers for early CRC detection. In this study we targeted glycoproteins secreted from the human colon carcinoma cell line LIM1215 as a source of potential CRC biomarkers. Secreted candidate glycoproteins were confirmed by MS and validated by Western blot analysis of tissue/tumour interstitial fluid (Tif) from LIM1215 xenograft tumours grown in immunocompromised mice. Overall, 39 glycoproteins were identified in LIM1215 culture media (CCM) and 5 glycoproteins in LIM1215 tumour xenograft Tif; of these, cadherin-17 (CDH17), galectin-3 binding protein (LGALS3BP), and tyrosine-protein kinase-like 7 (PTK7) were identified in both CM and glycosylation motifs. Swiss-Prot was used to annotate Tif. Many of the glycoproteins identified in this study (e.g., AREG, DSG2, EFNA1, EFNA3, EFNA4, EPHB4, ST14, and TIMP1) have been reported to be implicated in CRC biology. Interestingly, the cadherin-17 ectodomain, but not full length cadherin-17, was identified in CM, Tif and plasma derived from mice bearing the LIM1215 xenograft tumour. To our knowledge, this is the first report of the cadherin-17 ectodomain in plasma. In this study, we report for the first time that the presence of full-length cadherin-17 in exosomes released into the CM. This article is part of a Special Issue entitled: An Updated Secretome.     

Role of miRNA-210, miRNA-21 and miRNA-126 as diagnostic biomarkers in colorectal carcinoma: impact of HIF-1α-VEGF signaling pathway

Colorectal cancer (CRC) is a major cause of death worldwide. Novel non-invasive, high diagnostic value screening test is urgently needed to improve survival rate, treatment and prognosis. Stable, small, circulating microRNA (miRNA) offers unique opportunities for the early diagnosis of several diseases. It acts as tumor oncogenes or suppressors and involve in cell death, survival, and metastasis. Communication between miRNA and carcinogenesis is critical but it still not clear and needs further investigation. The aim of our study is to evaluate the role of miR-210, miR-21, miR-126, as non-invasive diagnostic biomarkers for screening, early detection of CRC, studying their correlation with prognostic variables, and clarifying the roles of miRNAs on HIF-1α-VEGF signaling pathway. The expression of miR-210, miR-21 and miR-126 was performed using qRT-PCR in adenocarcinoma (no?=?35), adenomas (no?=?51), and neoplasm free controls (no?=?101). Serum levels of VEGF and HIF-1α was determined by ELISA Kit. The results show that the expression of miR-210, miR-21, VEGF, HIF-1α was significantly up-regulated while that miRNA-126 was down-regulated in both adenocarcinoma and adenomas compared with controls (p?<?0.001 for each). No significant difference was noted comparing patients with adenocarcinoma and adenomas. The three miRNAs correlated with VEGF, HIF-α. The miR-210 and miR-21 associated with TNM classification and clinical staging of adenocarcinoma (p?<?0.001) and they show high diagnostic value with sensitivity and specificity 88.6%, 90.1% and 91.4%, 95.0% respectively. Our study revealed that circulating miR-210, miR-21 were up-regulated while miR-126 was down-regulated in CRC and adenomas patients, they all correlated with TNM staging and they had high diagnostic value. HIF-1α VEGF signaling pathways regulated by miRNAs played a role in colon cancer initiation. To the best of our knowledge, this is the first study of this miRNAs panel in CRC in our community. These data suggested that these biomarkers could be a potential novel, non-invasive marker for early diagnosis, screening and predicting prognosis of CRC. Understanding the molecular functions by which miRNAs affect cancer and understanding its roles in modulating the signaling output of VEGF might be fruitful in reducing the incidence and slowing the progression of this dark malignancy.

     

Discovery of a 29-Gene Panel in Peripheral Blood Mononuclear Cells for the Detection of Colorectal Cancer and Adenomas Using High Throughput Real-Time PCR

Colorectal cancer (CRC) is the second leading cause of cancer-related death in developed countries. Early detection of CRC leads to decreased CRC mortality. A blood-based CRC screening test is highly desirable due to limited invasiveness and high acceptance rate among patients compared to currently used fecal occult blood testing and colonoscopy. Here we describe the discovery and validation of a 29-gene panel in peripheral blood mononuclear cells (PBMC) for the detection of CRC and adenomatous polyps (AP). Blood samples were prospectively collected from a multicenter, case-control clinical study. First, we profiled 93 samples with 667 candidate and 3 reference genes by high throughput real-time PCR (OpenArray system). After analysis, 160 genes were retained and tested again on 51 additional samples. Low expressed and unstable genes were discarded resulting in a final dataset of 144 samples profiled with 140 genes. To define which genes, alone or in combinations had the highest potential to discriminate AP and/or CRC from controls, data were analyzed by a combination of univariate and multivariate methods. A list of 29 potentially discriminant genes was compiled and evaluated for its predictive accuracy by penalized logistic regression and bootstrap. This method discriminated AP >1cm and CRC from controls with a sensitivity of 59% and 75%, respectively, with 91% specificity. The behavior of the 29-gene panel was validated with a LightCycler 480 real-time PCR platform, commonly adopted by clinical laboratories. In this work we identified a 29-gene panel expressed in PBMC that can be used for developing a novel minimally-invasive test for accurate detection of AP and CRC using a standard real-time PCR platform.