Candidate microRNA biomarkers in human colorectal cancer: systematic review profiling studies and experimental validation

Colorectal cancer (CRC) is a major cause of cancer mortality worldwide. There is an urgent need to search for specific and sensitive biomarkers for early diagnosis of CRC. We carried out a comprehensive systematic review of published studies that compared the miRNA expression profiles between CRC tissue and paired neighboring noncancerous colorectal tissue to determine candidate miRNA biomarkers for CRC. A miRNA ranking system that takes the number of comparisons in agreement, total study sizes and direction of differential expression into the consideration was devised and used. One of the most up-regulated miRNAs, miRNA-106a, was consistently reported to be differentially expressed in six studies and the five most down-regulated miRNAs, miR-30a-3p, miR-139, miR-145, miR-125a and miR-133a, were consistently reported to be differentially expressed in four studies. Moreover, we further validated five miRNAs in a clinical setting using qRT-PCR, which demonstrated that miR-106a expression was increased, whereas the expression of miR-30a-3p, miR-145, miR-125a and miR-133a was decreased in the CRC tissues. Therefore, these miRNAs may be the candidates to develop a panel of biomarkers with sufficient sensitivity and specificity for the diagnosis of CRC in a clinical setting.     

Salivary metabolomics with machine learning for colorectal cancer detection

As the worldwide prevalence of colorectal cancer (CRC) increases, it is vital to reduce its morbidity and mortality through early detection. Saliva‐based tests are an ideal noninvasive tool for CRC detection. Here, we explored and validated salivary biomarkers to distinguish patients with CRC from those with adenoma (AD) and healthy controls (HC). Saliva samples were collected from patients with CRC, AD, and HC. Untargeted salivary hydrophilic metabolite profiling was conducted using capillary electrophoresis–mass spectrometry and liquid chromatography–mass spectrometry. An alternative decision tree (ADTree)‐based machine learning (ML) method was used to assess the discrimination abilities of the quantified metabolites. A total of 2602 unstimulated saliva samples were collected from subjects with CRC (n = 235), AD (n = 50), and HC (n = 2317). Data were randomly divided into training (n = 1301) and validation datasets (n = 1301). The clustering analysis showed a clear consistency of aberrant metabolites between the two groups. The ADTree model was optimized through cross‐validation (CV) using the training dataset, and the developed model was validated using the validation dataset. The model discriminating CRC + AD from HC showed area under the receiver‐operating characteristic curves (AUC) of 0.860 (95% confidence interval [CI]: 0.828‐0.891) for CV and 0.870 (95% CI: 0.837‐0.903) for the validation dataset. The other model discriminating CRC from AD + HC showed an AUC of 0.879 (95% CI: 0.851‐0.907) and 0.870 (95% CI: 0.838‐0.902), respectively. Salivary metabolomics combined with ML demonstrated high accuracy and versatility in detecting CRC.     

蛋白质组学在结直肠癌生物标志物研究中的应用

蛋白质组学是以蛋白质组为研究对象的一门崭新的生命科学,其技术主要包括样品的制备技术、双向凝胶电泳、差异凝胶电泳、多维蛋白质鉴定技术和表面增强激光解析电离飞行时间质谱等。结直肠癌是人类最常见的恶性肿瘤之一,近几年蛋白质组学在结直肠癌生物标志物的研究中取得了很大进展。本文对此作一综述。     

肺癌相关血清学肿瘤标志物研究进展

肿瘤生物标志物近年来一直是肿瘤基础和临床研究的一个十分活跃的领域.尽管迄今尚未找到肺癌特异性抗原,国内外研究人员已发现多种有潜力用于肺癌早期诊断、临床分型和分期、预后判断和疗效观察等的肿瘤生物标志.本文以癌胚抗原、神经元特异性烯醇化酶、细胞角蛋白19片段抗原、碳水化合物抗原242、粘蛋白1抗原、神经细胞粘附分子、组织多肽特异性抗原、干细胞因子、血管内皮生长因子、肝细胞生长因子、肺癌相关抗原和磷脂酰肌醇蛋白聚糖等为例,对肺癌相关血清学肿瘤生物标志物的研究进展作一综述.     

Pharmacokinetic parameters from 3-Tesla DCE-MRI as surrogate biomarkers of antitumor effects of bevacizumab plus FOLFIRI in colorectal cancer with liver metastasis

Bevacizumab (BV) is an antivascular endothelial growth factor antibody. When administered with other chemotherapeutic drugs, BV-combined regimens prolong survival of colorectal cancer patients. We conducted a phase II trial to confirm the pharmacokinetic parameters from 3-Tesla dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as surrogate biomarkers of BV + FOLFIRI regimen efficacy in colorectal cancer with liver metastases. DCE-MRI was performed before treatment, on the seventh day after first treatment and every 8 weeks thereafter using a 3-Tesla MRI system. DCE-MRI parameters-area under the contrast concentration versus time curve at 90 and 180 s (AUC90 and AUC180, respectively) after contrast injection, and volume transfer constant of contrast agents (K(trans) and K(ep) ) were calculated from liver metastases. Fifty-eight liver metastases were analyzed. Univariate analysis revealed that a decrease in K(trans) ratios (ΔK(trans) ), K(ep) ratios (ΔK(ep) ), AUC90 ratios (ΔAUC90) and AUC180 ratios (ΔAUC180) correlated with higher response (all p < 0.0001) and longer time to progression (TTP) (ΔK(trans) : p = 0.001; ΔK(ep) : p = 0.004; ΔAUC90: p = 0.006; ΔAUC180: p < 0.0001). Multivariate analysis showed that ΔAUC180 was correlated with higher response (p = 0.009), and ΔK(trans) and ΔAUC180 were correlated with longer TTP (ΔK(trans) : p = 0.001; ΔAUC180: p = 0.024). ΔK(trans) and ΔAUC180 are pharmacodynamic biomarkers of the blood perfusion of BV + FOLFIRI. Our data suggest that ΔK(trans) and ΔK(ep) can predict response to chemotherapy at 1 week. Changes in 3-Tesla DCE-MRI parameters confirmed the potential of these biomarkers of blood perfusion as surrogate predictors of response and TTP.     

Exploration of potential prognostic biomarkers in aflibercept plus FOLFIRI in Japanese patients with metastatic colorectal cancer

Aflibercept plus 5‐fluorouracil/levofolinate/irinotecan (FOLFIRI) is a second‐line treatment for metastatic colorectal cancer. This ancillary exploratory analysis of data in Japanese people was aimed at exploring the relationship between a set of potential prognostic biomarkers and efficacy endpoints following aflibercept plus FOLFIRI therapy. Sixty‐two patients with metastatic colorectal cancer received aflibercept (4 mg/kg) plus FOLFIRI every 2 weeks. Seventy‐eight potential protein biomarkers were chosen for analysis based on their roles in angiogenesis, tumor progression, and tumor‐stroma interaction. Plasma levels of biomarkers at baseline and at pre‐dose 3 (day 1 of treatment cycle 3) were measured in all patients by ELISA. Relationships between these levels and efficacy endpoints were assessed. Ten potential biomarkers had a ±30% change from baseline to pre‐dose 3 (adjusted P < .001), with the greatest changes occurring in placental growth factor (median: +4716%) and vascular endothelial growth factor receptor 1 (+2171%). Baseline levels of eight potential biomarkers correlated with overall survival in a univariate Cox regression analysis: extracellular newly identified receptor for advanced glycation end‐products binding protein, insulin‐like growth factor‐binding protein 1, interleukin‐8, kallikrein 5, pulmonary surfactant‐associated protein D, tissue inhibitor of metalloproteinases 1, tenascin‐C, and tumor necrosis factor receptor 2. None correlated with progression‐free survival or maximum tumor shrinkage. Pre‐dose 3 levels did not correlate with any efficacy endpoints. Preliminary data show that these eight biomarkers could be associated with overall survival. ClinicalTrials.gov identifier: NCT01882868.     

Tumor markers and colorectal cancer: utility in management

Colorectal cancer (CRC) is a leading cause of morbidity and mortality. Although genetic testing can screen for rare hereditary CRC syndromes, there is no ideal means of screening for sporadic forms of CRC. This review will focus on markers that are currently used in the management of sporadic CRC and their limitations, as well as possible future clinical applications.     

转移性结直肠癌中应用二代测序技术预测EGFR单抗疗效的研究*

目的:探索EGFR 单抗治疗转移性结直肠癌患者耐药性相关基因。方法:选取2012年3 月至2013年8 月在北京肿瘤医院接受EGFR 单抗治疗的31例转移性结直肠癌患者,利用二代测序技术检测肿瘤组织中与肿瘤发生、发展和EGFR 信号传导通路相关的21个基因,分析其与EGFR 单抗疗效的关系。结果:Kras 基因外显子2 为野生型的晚期结直肠癌的患者31例,接受EGFR 单抗单药三线治疗。全组患者中位PFS 为89d,OS为311 d,ORR 为16.1% 。5 例存在Kras 第3、4 外显子或者Nras 第2、3 外显子突变,均出现首次疗效评估PD（中位PFS 31d）。 其他突变包括1 例PIK3CA突变,PFS 为35d。1 例mTOR 突变,PFS 为91d。2 例患者存在SMAD 4 突变,PFS 分别是58d 及59d。1 例FBXW 7 突变,PFS 为93d。在26例全Ras基因野生型患者中MLL 3、TP53、APC 是突变频率最高的3 个基因。MLL 3 突变比例为92.3%（24/ 26）,TP53为53.8%（14/ 26）,APC 为42.3%（11/ 26）。 结论:进行EGFR 单抗治疗前必须进行Kras 及Nras 第2、3、4 外显子的检测,EGFR 通路下游信号分子,如PI 3KCA 、mTOR 等可能在EGFR 单抗疗效上起一定预测作用,针对EGFR 外的其他信号通路分子如SMAD 4、FBXW 7 等,需要进一步关注。      

Tumor markers in colorectal cancer,gastric cancer and gastrointestinal stromal cancers: European group on tumor markers 2014 guidelines update

Biomarkers currently play an important role in the detection and management of patients with several different types of gastrointestinal cancer, especially colorectal, gastric, gastro‐oesophageal junction (GOJ) adenocarcinomas and gastrointestinal stromal tumors (GISTs). The aim of this article is to provide updated and evidence‐based guidelines for the use of biomarkers in the different gastrointestinal malignancies. Recommended biomarkers for colorectal cancer include an immunochemical‐based fecal occult blood test in screening asymptomatic subjects ≥50 years of age for neoplasia, serial CEA levels in postoperative surveillance of stage II and III patients who may be candidates for surgical resection or systemic therapy in the event of distant metastasis occurring, K‐RAS mutation status for identifying patients with advanced disease likely to benefit from anti‐EGFR therapeutic antibodies and microsatellite instability testing as a first‐line screen for subjects with Lynch syndrome. In advanced gastric or GOJ cancers, measurement of HER2 is recommended in selecting patients for treatment with trastuzumab. For patients with suspected GIST, determination of KIT protein should be used as a diagnostic aid, while KIT mutational analysis may be used for treatment planning in patients with diagnosed GISTs.     

microRNA-221 and microRNA-18a identification in stool as potential biomarkers for the non-invasive diagnosis of colorectal carcinoma

Background:

The detection of microRNA (miRNA) dysregulation in stool is a novel approach for the diagnosis of colorectal carcinoma (CRC). The aim of this study is to investigate the use of miR-221 and miR-18a in stool samples as non-invasive biomarkers for CRC diagnosis.

Methods:

A miRNA expression array containing 667 miRNAs was performed to identify miRNA dysregulation in CRC tissues. We focused on miR-221 and miR-18a, two significantly upregulated miRNAs which were subsequently verified in 40 pairs of CRC tissues and 595 stool samples (198 CRCs, 199 polyps and 198 normal controls).

Results:

miR-221 and miR-18a were upregulated in the miRNA expression array. miR-221 and miR-18a levels were also significantly higher in 40 CRC tumours compared with their respective adjacent normal tissues. In stool samples, miR-221 and miR-18a showed a significant increasing trend from normal controls to late stages of CRC (P<0.0001). The levels of stool miR-221 and miR-18a were both significantly higher in subjects with stages I+II (miR-221: P<0.0001, miR-18a: P<0.0001) and stages III+IV of CRC (miR-221: P=0.0004, miR-18a: P<0.0001) compared with normal controls. The AUC of stool miR-221 and miR-18a were 0.73 and 0.67 for CRC patients as compared with normal controls, respectively. No significant differences in stool miR-221 and miR-18a levels were found between patients with proximal and distal CRCs. The use of antibiotics did not influence stool miRNA-221 and miRNA-18a levels.

Conclusions:

Stool-based miR-221 can be used as a non-invasive biomarker for the detection of CRC.     

蛋白质组学及其研究技术在肺癌分子生物标志物研究中的应用

肺癌是全球发病率和死亡率较高的恶性肿瘤。细胞从正常状态转变为肿瘤的过程中，细胞内蛋白质表达谱必然会发生一系列变化，肿瘤分子标记物就是细胞在非正常状态下产生的分子．以高通量结合生物信息学为特点的蛋白质组学分析技术可以从细胞整体水平上检测到这种变化近年来，为了降低肺癌的死亡率并提高其治疗效果，研究人员利用这一新的手段如利用激光捕获显微切割技术和双相凝胶电泳结合基质辅助激光解析电离飞行时间质谱（MALDI-TOF MS）和表面增强激光解析电离色行时间质谱（SELDI—TOF MS）寻找有效的肺癌标记物。本文对蛋白质组学技术在肺癌生物标志物研究中的应用作了综述。     

Serum IgG N-glycans enable early detection and early relapse prediction of colorectal cancer

Colorectal cancer (CRC) develops mainly from colorectal advanced adenomas (AA), which are considered precancerous lesions. Novel early diagnostic biomarkers are urgently needed to distinguish CRC and AA from healthy control (HC). Alternative glycosylation of serum IgG has been shown to be closely associated with CRC. We aimed to explore the potential of IgG N-glycan as biomarkers in the early differential diagnosis of CRC. The study population was strictly matched to the exclusion criteria process. Serum IgG N-glycan profiles were analyzed by a robust and reliable relative quantitative method based on ultra-performance liquid chromatography (UPLC). Relative quantification and classification performance of IgG N-glycans were evaluated by Mann-Whitney U tests and ROC curve based on directly detected and derived glycan traits, respectively. Six and 14 directly detected glycan traits were significantly changed in AA and CRC, respectively, compared with HC. GP1 and GP3 were able to accurately distinguish AA from HC for early precancerous lesions screening. GP4 and GP14 provided a high value in discriminating CRC from HC. A novel combined index named GlycoF, including GP1, GP3, GP4, GP14 and CEA was developed to provide a potential early diagnostic biomarker in discriminating simultaneously AA (AUC = 0.847) and CRC (AUC = 0.844) from HC. GlycoF also demonstrated a superior CRC detection rate across CRC all stages and conspicuous prediction ability of risk of relapse. Serum IgG N-glycans analysis provided powerful early screening biomarkers that can efficiently differentiate CRC and AA from HC.     

PIK3CA基因突变在结直肠癌中的研究进展

结直肠癌是较常见的恶性肿瘤,发病率在我国呈逐年上升趋势.肿瘤的发生是多因素、多阶段、多基因改变的结果,包括原癌基因的激活与抑癌基因的失活.PIK3 CA基因是近年发现的除KRAS突变之外的结直肠癌常见的突变基因,PI3K下游信号通路的异常活化在结直肠癌的发生过程中发挥着重要的作用.本文就PIK3CA基因的生物学作用,参与肿瘤不同阶段的发展,以及PIK3CA作为肿瘤标志物和分子靶点的潜在临床价值简要作一综述.     

Plasma microRNAs are promising novel biomarkers for early detection of colorectal cancer

MicroRNA (miRNA) opens up a new field for molecular diagnosis of cancer. However, the role of circulating miRNAs in plasma/serum in cancer diagnosis is not clear. The aim of this study was to investigate whether plasma miRNAs can be used as biomarkers for the early detection of colorectal carcinoma (CRC). We measured the levels of 12 miRNAs (miR‐134, −146a, −17‐3p, −181d, −191, −221, −222, −223, −25, −29a, −320a and −92a) in plasma samples from patients with advanced colorectal neoplasia (carcinomas and advanced adenomas) and healthy controls using real‐time RT‐PCR. We found that plasma miR‐29a and miR‐92a have significant diagnostic value for advanced neoplasia. MiR‐29a yielded an AUC (the areas under the ROC curve) of 0.844 and miR‐92a yielded an AUC of 0.838 in discriminating CRC from controls. More importantly, these 2 miRNAs also could discriminate advanced adenomas from controls and yielded an AUC of 0.769 for miR‐29a and 0.749 for miR‐92a. Combined ROC analyses using these 2 miRNAs revealed an elevated AUC of 0.883 with 83.0% sensitivity and 84.7% specificity in discriminating CRC, and AUC of 0.773 with 73.0% sensitivity and 79.7% specificity in discriminating advanced adenomas. Collectively, these data suggest that plasma miR‐29a and miR‐92a have strong potential as novel noninvasive biomarkers for early detection of CRC.     

Fluorescence‐based endoscopic imaging of Thomsen–Friedenreich antigen to improve early detection of colorectal cancer

Thomsen–Friedenreich (TF) antigen belongs to the mucin‐type tumor‐associated carbohydrate antigen. Notably, TF antigen is overexpressed in colorectal cancer (CRC) but is rarely expressed in normal colonic tissue. Increased TF antigen expression is associated with tumor invasion and metastasis. In this study, we sought to validate a novel nanobeacon for imaging TF‐associated CRC in a preclinical animal model. We developed and characterized the nanobeacon for use with fluorescence colonoscopy. In vivo imaging was performed on an orthotopic rat model of CRC. Both white light and fluorescence colonoscopy methods were utilized to establish the ratio‐imaging index for the probe. The nanobeacon exhibited specificity for TF‐associated cancer. Fluorescence colonoscopy using the probe can detect lesions at the stage which is not readily confirmed by conventional visualization methods. Further, the probe can report the dynamic change of TF expression as tumor regresses during chemotherapy. Data from this study suggests that fluorescence colonoscopy can improve early CRC detection. Supplemented by the established ratio‐imaging index, the probe can be used not only for early detection, but also for reporting tumor response during chemotherapy. Furthermore, since the data obtained through in vivo imaging confirmed that the probe was not absorbed by the colonic mucosa, no registered toxicity is associated with this nanobeacon. Taken together, these data demonstrate the potential of this novel probe for imaging TF antigen as a biomarker for the early detection and prediction of the progression of CRC at the molecular level.     

Targeted therapy for colorectal cancer metastases: A review of current methods of molecularly targeted therapy and the use of tumor biomarkers in the treatment of metastatic colorectal cancer

Despite recent advances in the management of colorectal cancer, metastatic disease remains challenging, and patients are rarely cured. However, a better understanding of the pathways implicated in the evolution and proliferation of cancer cells has led to the development of targeted therapies, that is, agents with action directed at these pathways/features. This approach is more specific to cells within which these pathways, such as epidermal growth factor receptor (EGFR), are overactive; this is in contrast to the relatively indiscriminate mechanism by which cytotoxic chemotherapy tends to affect rapidly dividing cells, regardless of their role. Although factors unique to a given patient, such as the location of the primary tumor (sidedness) or the presence of mutations that confer resistance, may limit the utility of these agents, targeted therapies are now a part of the treatment paradigm for metastatic colorectal cancer, and survival outcomes have significantly improved. This review provides an overview of the role of targeted therapy in the management of patients with colorectal cancer metastases as well as a discussion of issues in patient selection, with a focus on inhibitors of angiogenesis, EGFR-targeted therapy, BRAF mutation–targeted therapies, and other novel strategies, including immunotherapy.