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.     

MiR-320e is a novel prognostic biomarker in colorectal cancer

Background:

Advances in early detection and treatment have improved outcomes in patients with colorectal cancer (CRC). However, there remains a need for robust prognostic and predictive biomarkers. We conducted a systematic discovery and validation of microRNA (miRNA) biomarkers in two clinical trial cohorts of CRC patients.

Methods:

We performed an initial ‘discovery'' phase using Affymetrix miRNA expression arrays to profile stage III CRC patients with and without tumour recurrence (n=50 per group) at 3-years of follow-up. All patients received adjuvant 5-fluorouracil (5-FU) plus oxaliplatin, that is, FOLFOX, treatment. During ‘validation'', we analysed miRNAs using qRT–PCR in an independent cohort of 237 stage II–IV CRC patients treated with 5-FU-based chemotherapy, as well as in normal colonic mucosa from 20 healthy subjects. Association with disease recurrence, disease-free survival (DFS) and overall survival (OS) was examined using Cox proportional hazard models.

Results:

In the discovery cohort, miR-320e expression was significantly elevated in stage III colon cancers from patients with vs without recurrence (95% confidence interval (CI)=1.14–1.42; P<0.0001). These results were then independently validated in stage II and III tumours. Specifically, increased miR-320e expression was associated with poorer DFS (hazard ratio (HR)=1.65; 95% CI=1.27–2.13; P=0.0001) and OS (HR=1.78; 95% CI=1.31–2.41; P=0.0003) in stage III CRC patients.

Conclusions:

In two clinical trial cohorts, a systematic biomarker discovery and validation approach identified miR-320e to be a novel prognostic biomarker that is associated with adverse clinical outcome in stage III CRC patients treated with 5-FU-based adjuvant chemotherapy. These findings have important implications for the personalised management of CRC patients.     

Identification of serum microRNA profiles in colon cancer

Background:

microRNAs (miRNAs) exist in blood in an apparently stable form. We have explored whether serum miRNAs can be used as non-invasive early biomarkers of colon cancer.

Methods:

Serum samples from 30 patients with colon cancer stage IV and 10 healthy controls were examined for the expression of 375 cancer-relevant miRNAs. Based on the miRNA profile in this study, 34 selected miRNAs were measured in serum from 40 patients with stage I–II colon cancer and from 10 additional controls.

Results:

Twenty miRNAs were differentially expressed in serum from stage IV patients compared with controls (P<0.01). Unsupervised clustering revealed four subgroups; one corresponding mostly to the control group and the three others to the patient groups. Of the 34 miRNAs measured in the follow-up study of stage I–II patients, 21 showed concordant expression between stage IV and stage I–II patient. Based on the profiles of these 21 miRNAs, a supervised linear regression analysis (Partial Least Squares Regression) was performed. Using this model we correctly assigned stage I–II colon cancer patients based on miRNA profiles of stage IV patients.

Conclusion:

Serum miRNA expression profiling may be utilised in early detection of colon cancer.     

miR-92a 在结直肠癌中的表达及其对肿瘤血管生成的作用*

目的：探讨miR-92a 在结直肠癌中的表达及其对肿瘤血管新生功能的影响和作用机制。方法：采用qRT-PCR方法检测广东医学院附属深圳南山医院2014年6 月至2015年12月经手术切除的25例结直肠癌组织和对应癌旁组织及4 种结直肠癌细胞（HCT 116、SW620、SW480、HT29）中miR-92a 的表达;免疫组织化学法检测结直肠癌和癌旁组织中CD31阳性表达的微血管密度（microvesseldensity,MVD）,Pearson相关性分析探讨miR-92a 表达与肿瘤血管新生MVD的相关性。通过转染miR-92a-mimic、inhibitor 上调或抑制结直肠癌细胞HCT 116、SW620 中miR-92a 的表达水平,采用小管形成实验检测miR-92a 不同表达对HUVEC小管形成的影响,免疫印迹法检测对其下游潜在靶点PTEN的蛋白表达的影响。结果：结直肠癌组织miR-92a 的表达水平显著高于对应癌旁组织（P < 0.01）;4 种人结肠癌细胞系miR-92a 的表达水平均显著高于正常肠上皮组织（P < 0.05）;结直肠癌组织CD31阳性微血管密度显著高于癌旁组织（P < 0.01）,miR-92a 表达水平与结直肠癌血管新生MVD呈显著正相关（r = 0.580,P = 0.01）;上调miR-92a 表达的HCT 116 细胞培养上清液可以显著促进HUVEC小管形成（P < 0.05）;上调miR-92a 表达可以显著抑制HCT116 细胞中PTEN蛋白表达水平（P < 0.01）。 结论：miR-92a 在结直肠癌细胞和组织中高表达,与肿瘤血管新生增加密切相关;miR-92a 可能通过抑制PTEN的表达发挥促进结直肠癌血管新生的生物学功能。     

Fucosylated haptoglobin is a novel type of cancer biomarker linked to the prognosis after an operation in colorectal cancer

BACKGROUND:

Fucosylation is a crucial oligosaccharide modification in cancer and inflammation. Total cellular proteins of cancer cells and the sera of patients with cancer both show increased fucosylation levels. Certain kinds of fucosylated proteins can be applied as novel cancer biomarkers in glyco‐proteomic analyses. We previously identified fucosylated haptoglobin (Fuc‐Hpt) as a serologic marker for pancreatic cancer, and recently developed a lectin‐antibody enzyme‐linked immunosorbent assay system for quantifying Fuc‐Hpt. In the present study, we investigated the clinical outcome of Fuc‐Hpt levels in patients with colorectal cancer (CRC), and examined the mechanisms underlying Fut‐Hpt production using a murine tumor transplantation model.

METHODS:

The relationship between Fuc‐Hpt levels and clinical parameters was investigated in 77 patients with CRC, all of whom underwent primary resection. Serum Fuc‐Hpt levels were examined in athymic nude mice injected with colon cancer cell lines that lacked fucosylation.

RESULTS:

Fuc‐Hpt levels were significantly associated with overall and relapse‐free survival, distant metastasis, clinical stage, and curability. Multivariate analysis revealed that distant metastasis was an independent factor for increased Fuc‐Hpt levels. The combination of Fuc‐Hpt and CEA might be a better serologic marker to predict prognosis. Fuc‐Hpt levels were higher in mice with direct injection of tumor cells into the spleen than in those injected subcutaneously.

CONCLUSIONS:

Fuc‐Hpt might be a useful marker for the prognosis of CRC. Fuc‐Hpt could be produced by the tissue surrounding tumor cells, which might be the mechanism underlying Fuc‐Hpt elevation associated with distant metastasis. Cancer 2012;118: 3036–43. © 2011 American Cancer Society.     

Genome-wide microRNA profiles identify miR-378 as a serum biomarker for early detection of gastric cancer

Recent studies demonstrated that in several human malignancies aberrant expression profiles of circulating microRNAs (miRNAs) anticipate great cancer diagnostic potential. Here we showed that serum miR-378 could serve as a novel noninvasive biomarker in gastric cancer (GC) detection. Genome-wide miRNA expression profiles followed with Real-Time quantitative RT-PCR (qRT-PCR) assays revealed that miR-187^*, miR-371-5p and miR-378 were significantly elevated in GC patients. Further validation indicated that miR-378 alone could yields a ROC curve area of 0.861 with 87.5% sensitivity and 70.73% specificity in discriminating GC patients from healthy controls. Collectively, these data support our contention that serum miR-378 has strong potential as a novel noninvasive biomarker in gastric cancer detection.     

SCTR hypermethylation is a diagnostic biomarker in colorectal cancer

Diagnostic markers for both colorectal cancer (CRC) and its precursor lesions are lacking. Although aberrant methylation of the secretin receptor (SCTR) gene was observed in CRC, the diagnostic performance has not been evaluated. Therefore, this study aimed to assess and verify the diagnostic value of SCTR methylation of CRC and its precursor lesions through integrating the largest methylation data. The diagnostic performance of SCTR methylation was analyzed in the discovery set from The Cancer Genome Atlas (TCGA) CRC methylation data (N = 440), and verified in a large‐scale test set (N = 938) from the Gene Expression Omnibus (GEO). Targeted bisulfite sequencing analysis was developed and applied to detect the methylation status of SCTR in our independent validation set (N = 374). Our findings revealed that the SCTR gene was frequently hypermethylated at its CpG islands in CRC. In the TCGA discovery set, the diagnostic score was constructed using 4 CpG sites (cg01013590, cg20505223, cg07176264, and cg26009192) and achieved high diagnostic performance (area under the ROC curve [AUC] = 0.964). In the GEO test set, the diagnostic score had robust diagnostic ability to distinguish CRC (AUC = 0.948) and its precursor lesions (AUC = 0.954) from normal samples. Moreover, hypermethylation of the SCTR gene was also found in cell‐free DNA samples collected from CRC patients, but not in those from healthy controls. In the validation set, consistent results were observed using the targeted bisulfite sequencing array. Our study highlights that hypermethylation at CpG islands of the SCTR gene is a potential diagnostic biomarker in CRCs and its precursor lesions.     

Identification of a bona fide microRNA biomarker in serum exosomes that predicts hepatocellular carcinoma recurrence after liver transplantation

Background

Predictive biomarkers for the recurrence of hepatocellular carcinoma (HCC) have great benefit in the selection of treatment options, including liver transplantation (LT), for HCC. The purpose of this study was to identify specific microRNAs (miRs) in exosomes from the serum of patients with recurrent HCC and to validate these molecules as novel biomarkers for HCC recurrence.

Methods

We employed microarray-based expression profiling of miRs derived from exosomes in the serum of HCC patients to identify a biomarker that distinguishes between patients with and without HCC recurrence after LT. This was followed by the validation in a separate cohort of 59 HCC patients who underwent living related LT. The functions and potential gene targets of the recurrence-specific miRs were analysed using a database, clinical samples and HCC cell lines.

Results

We found that miR-718 showed significantly different expression in the serum exosomes of HCC cases with recurrence after LT compared with those without recurrence. Decreased expression of miR-718 was associated with HCC tumour aggressiveness in the validated cohort series. We identified HOXB8 as a potential target gene of miR-718, and its upregulation was associated with poor prognosis.

Conclusion

Circulating miRs in serum exosomes have potential as novel biomarkers for predicting HCC recurrence.     

Serum haptoglobin as a novel molecular biomarker predicting colorectal cancer hepatic metastasis

Early detection of liver metastasis is important for improving colorectal cancer (CRC) patient survival. Our previous studies showed haptoglobin was highly expressed in primary CRC tissues, especially in heterochronous metastatic cases. Here, we assessed the potential of serum haptoglobin (sHP) as a biomarker for early detection of CRC liver metastasis by evaluating the sHP in 475 CRC patients and 152 healthy volunteers. In the training set (250 cases), sHP level in CRC‐M1 (1773.18 ± 690.25 ng/mL) were significantly increased as compared to in CRC‐M0 (1544.37 ± 1497.65 ng/mL) or healthy (917.76 ± 571.59 ng/mL). And the high sHP level was correlated with poor survival. Logistic regression analysis revealed that sHP, serum carcinoembryonic antigen (sCEA) and serum carbohydrate antigen 19.9 (sCA19.9) level were the significant parameters for detecting liver metastasis. In leave‐one‐out‐cross‐validation, these three markers resulted in 89.1% sensitivity and 85.8% specificity for hepatic metastasis detection. In an independent test set (225 cases), receiver operating characteristic curve analysis of sHP in CRC liver metastasis showed an area under the curve of 0.735, with a sensitivity of 87.2% and a specificity of 59.9%. Combination of sHP, sCEA and sCA19.9 improved diagnostic accuracy to 0.880, with a sensitivity of 88.5% and a specificity of 87.8%. Silencing of HP by specific shRNA significantly inhibited the LOVO and SW620 cell invasion, and suppressed xenograft tumor invasive growth. In summary, these results demonstrate that sHP is associated with poor prognosis of CRC patients and that HP promotes colorectal cancer cell invasion. sHP combining with sCA19.9 and sCEA may be used as accurate predictors of CRC liver metastasis.     

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。     

RAB27B-activated secretion of stem-like tumor exosomes delivers the biomarker microRNA-146a-5p,which promotes tumorigenesis and associates with an immunosuppressive tumor microenvironment in colorectal cancer

The dynamic cell–cell communication is essential for tissue homeostasis in normal physiological circumstances and contributes to a diversified tumor microenvironment. Although exosomes are extracellular vesicles that actively participate in cell–cell interaction by shutting cellular components, impacts of tumor exosomes in the context of cancer stemness remain elusive. Here, we expand colorectal cancer stem cells (CRCSCs) as cancer spheroids and demonstrate that the β-catenin/Tcf-4-activated RAB27B expression is required for the secretion of CRCSC exosomes. In an exosomal RNA sequencing analysis, a switch of exosomal RNA species from retrotransposons to microRNAs (miRNAs) is identified upon expanding CRCSCs. miRNA-146a-5p (miR-146a) is the major miRNA in CRCSC exosomes and exosomal miR-146a promotes stem-like properties and tumorigenicity by targeting Numb in recipient CRC cells. Among 53 CRC patients, those with abundant exosomal miR-146a expression in serum exhibits higher miR-146a^High/Numb^Low CRCSC traits, an increased number of tumor-filtrating CD66(+) neutrophils and a decreased number of tumor-infiltrating CD8(+) T cells. Our study elucidates a unique mechanism of tumor exosome-mediated stemness expansion.     

MicroRNA profiling with correlation to gene expression revealed the oncogenic miR-17-92 cluster to be up-regulated in osteosarcoma

Osteosarcomas are genetically complex tumors with abundant structural and numerical alterations. The molecular pathogenesis of the disease is, however, still poorly understood. Aside from various oncogenes and tumor suppressor genes, deregulated microRNAs (miRNAs) are known to influence tumor development and biology. We therefore investigated six well-established osteosarcoma cell lines (HOS58, U2-OS, Saos-2, MNNG/HOS, SJSA-1, and MG-63) for genome-wide miRNA expression (miRBase Version 15.0, http://www.mirbase.org/) and correlated our findings with gene expression. Cultured osteoblasts (hFOB 1.19) and mesenchymal stem cells (L87/4) were used as normal references. Focusing only on miRNAs that were deregulated in the majority of osteosarcoma cell lines, we identified several miRNAs with oncogenic and tumor suppressor properties, including various members of the oncogenic miR-17-92 cluster. In addition, several genes involved in differentiation (RGMB, LRRC17), cell cycle control (CCNE1), and apoptosis (LIMA1, CAMK2N1) were found to be deregulated in osteosarcoma cell lines, most likely due to altered miRNA expression patterns. Our findings indicate a crucial impact of deregulated miRNAs with consecutive changes in gene expression in osteosarcomas, which strongly suggests pathogenetic and potentially therapeutic implications.     

miR-19a acts as an oncogenic microRNA and is up-regulated in bladder cancer

Background

The application of microRNAs (miRNAs) as potential biomarkers and therapy targets has been widely investigated in many kinds of cancers. The discovery of tumor associated miRNAs in serum of patients supported the use of plasma/serum miRNAs as noninvasive means of cancer detection. However, the aberrant expression of miRNAs in bladder cancer patients and their intensive roles and mechanisms in bladder cancer are poorly understood.

Methods

Taqman probe stem-loop real-time PCR was used to accurately measure the levels of miR-19a in bladder cancer cell lines, 100 pairs of bladder cancer tissues and the adjacent non-neoplastic tissues and also the plasma collected from bladder cancer patients and normal controls. miR-19a mimics and inhibitors were transfected into bladder cancer cells to investigate its role on regulating cell proliferation which was measured by CCK-8 and colony formation assay. The target of miR-19a was identified by western blot and whether its regulatory role depends on its target was improved by a rescue experiment with miR-19a mimic and PTEN expression plasmid.

Results

miR-19a was significantly up-regulated in bladder cancer tissues and high-level of miR-19a was correlative with more aggressive phenotypes of bladder cancer. Meanwhile, gain or loss of function of miR-19a demonstrated that miR-19a can promote cell growth of bladder cancer cells and the further mechanism studies indicated that its oncogenic role was dependent on targeting PTEN. Furthermore, investigation of miR-19a expression in the plasma of bladder cancer patients showed that miR-19a was also increased in plasma of bladder cancer patients which strongly supported miR-19a could be developed as potential diagnostic marker of bladder cancer.

Conclusions

Our data indicated that miR-19a might act as an oncogenic microRNA in bladder cancer and was significantly up-regulated in bladder cancer carcinogenesis. The oncogenic role of miR19a in bladder cancer was dependent on targeting PTEN.     

Exosomal zinc transporter ZIP4 promotes cancer growth and is a novel diagnostic biomarker for pancreatic cancer

Pancreatic cancer is one of the deadliest cancers with rapid disease progression. Further elucidation of its underlying molecular mechanisms and novel biomarkers for early detection is necessary. Exosomes are small extracellular vesicles that are released by multiple cell types acting as message carriers during intercellular communication and are promising biomarker candidates. However, the role of pancreatic cancer cell‐derived exosomes in cancer progression and the application of these vesicles as novel diagnostic biomarkers have not been fully studied. In this study, we found that PC‐1.0 (a highly malignant pancreatic cell line) cell‐derived exosomes could be taken up by and enhance PC‐1 (a moderately malignant pancreatic cell line) cell proliferation, migration and invasion abilities. We identified ZIP4 as the most upregulated exosomal protein in PC‐1.0 cells from our proteomic analysis. In vitro and in vivo (a subcutaneous BALB/c nude mouse model) studies showed that exosomal ZIP4 can significantly promote pancreatic cancer growth. Using clinical blood samples, we compared the diagnostic values of serum exosomal ZIP4 levels between malignant pancreatic cancer patients (n = 24) and benign pancreatic disease patients (n = 32, AUC = .89), and between biliary disease patients (n = 32, AUC = .8112) and healthy controls (n = 46, AUC = .8931). In conclusion, exosomal ZIP4 promotes cancer growth and is a novel diagnostic biomarker for pancreatic cancer.     

Telomere length is a novel predictive biomarker of sensitivity to anti-EGFR therapy in metastatic colorectal cancer

Background:

Telomeres are TTAGGG tandem repeats capping chromosomal ends and partially controlled by the telomerase enzyme. The EGFR pathway putatively regulates telomerase function, prompting an investigation of telomere length (TL) and its association with anti-epidermal growth factor receptor (EGFR) therapy in metastatic colorectal cancer (mCRC).

Methods:

Colorectal cancer cell lines were treated with multiple drugs and sensitivity determined. Clinical information was gathered from 75 patients who had received anti-EGFR drugs. Telomere length was measured using a validated qRT–PCR technique.

Results:

In CRC cell lines, TL independently predicted cetuximab sensitivity. Cells with shorter TL had growth inhibition of 18.6±3.41% as compared with 41.39±8.58% in longer TL (P=0.02). These in vitro findings were validated clinically, in a robust multivariate model. Among patients with KRas WT tumours, those with longer TL had a superior median progression-free survival (PFS) of 24.9 weeks than those with shorter TL; median 11.1 weeks, HR 0.31; P=0.048.

Conclusion:

Telomere length could be a potential unique biomarker predictive of clinical benefit (PFS) of mCRC patients treated with anti-EGFR therapy. This is the novel demonstration of a complex hitherto undescribed interaction, placing anti-EGFR therapy, EGFR pathway, and the telomerase complex within a clinical context.     

MicroRNA-143 is a putative predictive factor for the response to fluoropyrimidine-based chemotherapy in patients with metastatic colorectal cancer

Approximately half of the colorectal cancer (CRC) patients develop metastatic disease. Fluoropyrimidine-based chemotherapy forms the backbone of treatment in these patients. However, the response to this therapy varies between individuals. Therefore, an important challenge in CRC research is to identify biomarkers that are predictive of this response. In this study, we explored the potential of miRNAs, and the miRNA producing protein Dicer, as biomarkers that can predict chemo-sensitivity to fluoropyrimidine chemotherapy in patients with metastatic colorectal cancer (mCRC). We analyzed the levels of 22 miRNAs and the Dicer protein in primary tumors from patients with mCRC who were treated with first-line capecitabine monotherapy within the CAIRO trial of the Dutch Colorectal Cancer Group. Correlation between the expression status of miRNAs or Dicer in primary tumors and the progression free survival (PFS) were investigated. Patients with low expression of miR-143 in their primary tumor had increased median PFS compared to those with high expression of miR-143. Furthermore, FXYD3, an ion transport regulator and a putative target of miR-143, also showed an association with PFS. These findings warrant further studies to investigate the relationship between miR-143, FXYD3 and fluoropyrimidines, and the clinical utility of miR-143 as biomarker.     

Serum microRNA expression profile: miR-1246 as a novel diagnostic and prognostic biomarker for oesophageal squamous cell carcinoma

Background:

Recent studies have demonstrated that microRNAs (miRNAs) are stably detectable in blood and can serve as useful biomarkers for cancer.

Methods:

We performed an miRNA array using serum samples obtained from oesophageal squamous cell carcinoma (ESCC) patients or healthy controls. MiR-1246 was the most markedly elevated in ESCC patients. Therefore, miR-1246 was selected as a candidate for further analysis. The serum miR-1246 level in 46 healthy controls and 101 ESCC patients was evaluated and compared among various clinicopathological characteristics. MiR-1246 expressions in tissue, exosomal, and cellular samples were also examined.

Results:

Serum miR-1246 alone yielded an receiver-operating characteristic curve area of 0.754, with 71.3% sensitivity and 73.9% specificity for distinguishing ESCC patients from healthy controls. Serum miR-1246 was significantly correlated with the TNM stage and showed to be the strongest independent risk factor for poor survival (HR, 4.032; P=0.017). Unlike the tendency shown in previous reports, miR-1246 was not upregulated in ESCC tissue samples. Furthermore, exosomal miR-1246 did not reflect the abundance in the cell of origin.

Conclusion:

These data support our contention that serum miR-1246 has strong potential as a novel diagnostic and prognostic biomarker in ESCC, and its releasing mechanism is selective and independent of tissue miRNA abundance.