Circulating cell-free microRNAs as biomarkers for colorectal cancer

Comparison between Clinical Utility of CXCL-8 and Clinical Practice Tumor Markers for Colorectal Cancer Diagnosis

Owing to the high incidence and mortality rates of colorectal cancer (CRC), novel biomarkers for CRC diagnosis are critically needed. Therefore, this study is aimed at exploring the clinical utility of serum C-X-C motif chemokine 8 (CXCL-8) for CRC diagnosis and progression compared to the routinely used biomarkers, carcinoembryonic antigen (CEA), and carbohydrate antigen-19-9 (CA19-9). This study included 227 patients with CRC, 110 patients with colorectal adenoma (CA), and 123 healthy participants, who were recruited from the Fujian Medical University Union Hospital from July 1, 2019 to October 31, 2020. Serum concentrations of CXCL-8, CEA, and CA19-9 were detected using enzyme-linked immunosorbent assay and chemiluminescent microparticle immunoassay. Clinicopathological features of patients with CRC were collected and analyzed. The diagnostic efficacy of CXCL-8, CEA, and CA19-9 for CRC was evaluated using receiver operating characteristic (ROC) curves. We found that the serum concentrations of CXCL-8, CEA, and CA19-9 were significantly higher in patients with CRC than those in patients with CA and healthy controls. The diagnostic sensitivity of CXCL-8 alone was higher than those of CEA and CA19-9 both and when combined; thus, CXCL-8 may be better at discriminating patients with CRC from healthy controls and patients with CA. Moreover, combining CXCL-8 with CEA or CA19-9 improved their respective diagnostic performances in distinguishing patients with CRC from CA patients and healthy participants. Notably, we also found that serum concentrations of CXCL-8 were positively correlated with metastases and tumor size. Therefore, our study suggests that serum CXCL-8 may serve as an improved biomarker for CRC diagnosis compared to the traditional tumor markers CEA and CA19-9. Moreover, our findings indicate the potential efficacy of serum CXCL-8 levels as a CRC prognostic biomarker.

Serum hsa-miR-30e As a Potential Biomarker to Predict the Effect of Neoadjuvant Chemoradiation Therapy in Locally Advanced Rectal Cancer

Objective: To identify serum microRNAs (miRNAs) correlated with response to neoadjuvant chemoradiation therapy (NCRT) in locally advanced rectal cancer (LARC) patients using in silico analysis and laboratory validation studies. Methods: GSE68204 and GSE68204 data sets were analyzed to identify differentially expressed (DE) miRNAs in NCRT responders using the GEO2R Limma package within the R software suite. Then we used quantitative real-time polymerase chain reaction to detect the upregulated target miRNAs in the serum of 20 LARC patients. Logistic regression was used to evaluate the effect of serum miRNA level on response. Gene Ontology and pathway enrichment analyses were performed to predict the corresponding functions of the DE miRNAs. Correlation between the expression of the hub target genes and the abundance of tumor-infiltrating lymphocytes was further investigated. Results: hsa-miR-30e and hsa-miR-210 were verified to be upregulated in tumor tissues of NCRT responders. Subsequent liquid-biopsy studies revealed that the serum level of miR-30e was associated with a 2.47-fold increased incidence of NCRT-responsive patients in comparison with nonresponders (p-value = 0.038, Mann-Whitney test). Nine hub target genes of hsa-miR-30e were enriched in pathways including immune regulation. The expression of these hub target genes was correlated with abundance of tumor-infiltrating lymphocytes. Conclusion: In summary, hsa-miR-30e was determined to be upregulated in rectal cancer tissues of NCRT-responders. Further investigations showed that increased serum levels of hsa-miR-30e were associated with an effective NCRT response in LARC patients.

Exosomal miR-155 Derived from Hepatocellular Carcinoma Cells Under Hypoxia Promotes Angiogenesis in Endothelial Cells

PURPOSE

In this study, we aim to clarify whether exosomes secreted from hepatocellular carcinoma (HCC) cells under hypoxia affect angiogenesis in endothelial cells.

METHODS

Exosomes derived from human liver cancer cell lines were cultured under hypoxic or normoxic conditions for 24 h, isolated using ExoQuick-TC^®, and co-cultured with HUVECs to evaluate angiogenic activity. We also evaluated the expression of miR-155 in the exosomes from 40 patients with HCC.

RESULTS

Exosomes under hypoxia remarkably enhanced tube formation of HUVECs. Both cellular and exosomal miR-155 were significantly up-regulated under hypoxic conditions. Knockdown of miR-155 in HCC cells attenuated the promotion of tube formation by exosomes under hypoxia in HUVECs, and high expression of exosomal miR-155 in preoperative plasma was significantly correlated with early recurrence.

CONCLUSION

These results suggest that exosomes derived from HCC cells under hypoxia induce tube formation of HUVECs and that exosomal miR-155 may affect angiogenic activity in HCC.

Systematic review of blood diagnostic markers in colorectal cancer

The purpose of this systematic review was to compare the diagnostic ability of blood markers for colorectal cancer (CRC). A systematic review of the literature for diagnostic blood markers for primary human colorectal cancer over the last 5 years was performed. The primary outcome was to assess the diagnostic ability of these markers in diagnosing colorectal cancer. The secondary outcome was to see whether the marker was compared to other markers. The tertiary outcome was to assess diagnostic ability in early versus late CRC, including stage IV disease. We identified 51 studies (29 prospective, 14 retrospective, and 8 meta-analyses). The markers were divided in broadly four groups: nucleic acids (RNA/DNA/messenger RNA/microRNAs), cytokines, antibodies, and proteins. The most promising circulating markers identified among the nucleid acids were NEAT_v2 non-coding RNA, SDC2 methylated DNA, and SEPT9 methylated DNA. The most promising cytokine to detect CRC was interleukin 8, and the most promising circulating proteins were CA11-19 glycoprotein and DC-SIGN/DC-SIGNR. Sensitivities of these markers for detecting primary colorectal carcinoma ranged from 70 to 98% and specificities from 84 to 98.7%. The best studied blood marker was SEPT9 methylated DNA, which showed great variability with sensitivities ranging from 48.2 to 95.6% and specificities from 80 to 98.9%, making its clinical applicability challenging. If combined with fecal immunochemical test (FIT), the sensitivity improved from 78 to 94% in detecting CRC. Methylated SEPT9, methylated SDC2, and -SIGN/DC-SIGNR protein had better sensitivity and specificity than CEA or CA 19-9. With the exception of SEPT9 which is currently being implemented as a screening test for CRC all other markers lacked reproducibility and standardization and were studied in relatively small population samples.

A miR-29b Byproduct Sequence Exhibits Potent Tumor-Suppressive Activities via Inhibition of NF-κB Signaling in KRAS-Mutant Colon Cancer Cells

We previously demonstrated that miR-29b-3p is a hopeful miRNA-based therapy against colorectal cancer. In this study, we aimed to clarify a value of miR-29b-1-5p as a next-generation treatment, especially for KRAS-mutant colorectal cancer. RT-PCR assay showed that the expression of miR-29b-3p was high, and its partner strand, miR-29b-1-5p, level was only negligible in clinical colorectal cancer samples. Mimic-miR-29b-1-5p significantly inhibited proliferation of KRAS-mutant colorectal cancer cell lines DLD1 and SW480 and KRAS wild-type HT29 cells. Proliferative activity was further examined by either miR-29b-1-5p strand or its opposite complementary sequence because miR-29b-1-5p is a passenger miRNA and may have no physiologic function. We found that completely opposite complementary strand to miR-29b-1-5p, but not miR-29b-1-5p, possessed a potent antitumor effect and named this byproduct miRNA sequence "MIRTX." MIRTX directly targeted the 3'-UTR of CXCR2 and PIK3R1 mRNA and suppressed the NF-κB signaling pathway in KRAS-mutated colorectal cancer cells. MIRTX induced apoptosis in DLD1 with downregulation of antiapoptotic BCL2, BCL-xL, and MCL1 and upregulation of cleaved caspase-3 and cleaved PARP. In mouse xenograft models, systemic administration of MIRTX using a super carbonate apatite as a delivery vehicle significantly inhibited tumor growth of DLD1 and HT29 cells without any particular toxicities. In conclusion, these findings indicate that inhibition of NF-κB signaling by this novel miRNA-based therapeutic could be a promising treatment against refractory KRAS-mutant colorectal cancer and KRAS wild-type colorectal cancer. Mol Cancer Ther; 17(5); 977-87. ©2018 AACR.

Long non-coding RNAs LOC285194, RP11-462C24.1 and Nbla12061 in serum provide a new approach for distinguishing patients with colorectal cancer from healthy controls

Colorectal cancer (CRC) is currently the most prevalent malignant cancer worldwide. However, there is a lack of efficient biomarkers for CRC screening. Accumulating evidence reveals that long non-coding RNAs (lncRNAs) detectable in serum are associated with the genesis and development of various types of cancer. Therefore, we examined the diagnostic ability of lncRNAs in blood samples from patients with CRC by evaluating the levels of 17 CRC- or gastrointestinal cancer-related lncRNAs in serum samples from 71 CRC patients and 70 healthy individuals using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We detected 13 lncRNAs in serum, three of which displayed significantly different levels between CRC patients and healthy controls. A three-lncRNA signature (LOC285194, RP11-462C24.1 and Nbla12061) identified via stepwise regression analysis showed potential as a diagnostic marker for CRC. The area under the receiver operating characteristic curve of this signature for distinguishing CRC patients from healthy individuals was 0.793 (95% CI: 0.709 to 0.861). The diagnostic ability of this marker was much higher than that of conventional blood biomarkers such as carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199), carbohydrate antigen 125 (CA125) and carbohydrate antigen 724 (CA724). Combining this novel marker with conventional biomarkers produced even greater diagnostic ability. Furthermore, the levels of the three lncRNAs decreased after the patients underwent surgical resection. The results of this study suggest an additional marker for CRC screening and provide new directions for further investigation.

Downregulation of serum metabolite GTA-446 as a novel potential marker for early detection of colorectal cancer

BACKGROUND

We previously reported that GTA-446 may be a useful biomarker for early detection of colorectal cancer. In the present study, we confirmed the clinical feasibility of GTA-446 as a screening tool for colorectal cancer with a novel measurement system developed for clinical use. We also improved sensitivity by analysing GTA-446 levels according to gender.

METHODS

Serum samples were collected from 225 colorectal cancer patients and 916 healthy volunteers to measure GTA-446 levels by flow injection analysis-mass spectrometry.

RESULTS

GTA-446 levels were downregulated in colorectal cancer patients compared with the healthy volunteers, and in females compared with the males in both groups. Receiver operating characteristic curve analysis revealed an optimal cut-off of 2.72 μmol l^-1 in males and 1.87 μmol l^-1 in females, with a large area under the curve of 0.89-0.93. The sensitivity and specificity were 90.4% and 84.9% for males, 85.2% and 80.5% for females, and 83.3% and 84.8% for all subjects, respectively.

CONCLUSIONS

GTA-446 is a clinically relevant biomarker for colorectal cancer with high sensitivity when analysed by gender. Thus, GTA-446 is a promising tool for primary colorectal cancer screening to identify populations at a higher risk of colorectal cancer, with an emphasis on early detection.

Circulating cell-free microRNAs as clinical cancer biomarkers

MicroRNAs (miRNAs) are non-coding small RNAs that are master regulators of genic expression and consequently of many cellular processes. But their expression is often deregulated in human tumors leading to cancer development. Recently miRNAs were discovered in body fluids (serum, plasma and others) and their levels have often been reported to be altered in patients. Circulating miRNAs became one of the most promising biomarkers in oncology for early diagnosis, prognosis and therapeutic response prediction. Here we describe the origins and roles of miRNAs, and summarize the most recent studies focusing on their usefulness as cancer biomarkers in lung, breast, colon, prostate, ovary cancers and melanoma. Lastly, we describe the main methodologies related to miRNA detection, which should be standardized for their use in clinical practice.

Dynamic monitoring of circulating microRNAs as a predictive biomarker for the diagnosis and recurrence of papillary thyroid carcinoma

Circulating microRNAs (miRNAs/miRs) are considered to be potential biomarkers for numerous types of cancer. However, previous investigations into the expression of miRNAs in the serum of patients with papillary thyroid carcinoma (PTC) to predict diagnosis, prognosis and recurrence have reported conflicting results, and the role of miRNAs remains unclear. The present study dynamically assessed the circulating miRNA profile in patients with PTC and determined whether miRNAs in the serum could be used as biomarkers for the diagnosis, prognosis and recurrence of PTC. The expression levels of 3 reportedly upregulated miRNAs (miR-222, miR-221 and miR-146b) were analyzed using reverse transcription-quantitative polymerase chain reaction in 106 patients with PTC, 35 patients with benign thyroid nodules (BTN) and 40 paired controls. Patients with either newly diagnosed PTC or BTN who were undergoing thyroidectomies were recruited for a dynamic analysis of preoperative and postoperative serum miRNA levels. The results indicated that the expression levels of serum miR-222, miR-221 and miR-146b were significantly increased in patients with newly diagnosed PTC compared with controls and patients with BTN. Receiver operating characteristic curve analysis indicated that these miRNAs had a high diagnostic sensitivity and specificity for PTC prior to surgery. The expression of these three miRNAs in serum was significantly associated with poorer prognostic variables, including extrathyroidal invasion, metastatic lymph nodes and high-risk or advanced tumor node metastasis stage. More notably, the present study identified 2.36-, 2.69- and 5.39-fold reductions in the serum levels of miR-222, miR-221 and miR-146b, respectively, subsequent to patients undergoing a thyroidectomy. In addition, miR-222, miR-221 and miR-146b were overexpressed in the PTC with recurrence group compared with the PTC without recurrence group. Collectively, dynamic monitoring of circulating miRNAs may serve as a non-invasive biomarker for the diagnosis of PTC and the postoperative monitoring of its progression and recurrence.

Serum miR-143 levels predict the pathological response to neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer

Recently, several circulating miRNAs have been reported as promising, minimally invasive biomarkers for the diagnosis or prediction of the prognosis in various types of cancer. However, the utility of circulating miRNAs as predictive markers of the cancer response to neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer is still unclear. To identify circulating serum miRNAs useful for predicting a pathological good response to nCRT, total 18 serum miRNAs of interest were analyzed by real-time polymerase chain reaction in 94 rectal cancer patients treated with nCRT and surgery. Pathological complete response (pCR; Dworak TRG4) and near-pCR (TRG3) were obtained in 12 (13%) and 9 (9%) patients respectively, and we regarded them as nCRT-responders. Of the 18 serum miRNAs, only the serum level of miR-143 was identified significantly associated with a pathological response to nCRT in 94 patients; the serum miR-143 level was significantly lower in nCRT-responders than in non-responders. A multivariate analysis incorporating other clinicopathological factors showed that only the serum miR-143 level was an independent predictor of a good pathological response. The circulating serum miR-143 level may be a novel, non-invasive predictive marker of a response to nCRT in locally advanced rectal cancer patients.

Histopathologic risk stratification of stage IIB colorectal cancer

PURPOSE

To stratify stage IIB (pT4a PN0) colorectal cancer in terms of histopathologic findings.

METHODS

We reviewed the medical records of 80 patients who underwent surgery for stage IIB colorectal cancer. The disease-free survival (DFS) and overall survival (OS) rates were evaluated and correlated with the presence or absence of "Tumor Necrosis", "Crohn's-like lymphoid reaction", and "Perineural Invasion".

RESULTS

Patients with "Tumor Necrosis" had significantly lower DFS rates (p < 0.0001), those with "Crohn's-like lymphoid reaction" had significantly higher DFS rates (p = 0.037), and those with "Perineural Invasion" had significantly lower DFS rates (p < 0.0001). Patients with "Tumor Necrosis" had significantly lower OS rates (p = 0.016), those with "Crohn's-like lymphoid reaction" had significantly higher OS rates (p = 0.022), and those with "Perineural Invasion" had significantly lower OS rates (p = 0.003).

CONCLUSIONS

Since stage IIB colorectal cancers accompanied by the pathological findings of "Tumor Necrosis" and "Perineural Invasion", but with the absence of "Crohn's-like lymphoid reaction" carried a poor prognosis, the efficacy of adjuvant chemoradiation must be considered for these patients.

Dysregulated MicroRNA Expression Profiles and Potential Cellular, Circulating and Polymorphic Biomarkers in Non-Hodgkin Lymphoma

A large number of studies have focused on identifying molecular biomarkers, including microRNAs (miRNAs) to aid in the diagnosis and prognosis of the most common subtypes of non-Hodgkin lymphoma (NHL), Diffuse Large B-cell Lymphoma and Follicular Lymphoma. NHL is difficult to diagnose and treat with many cases becoming resistant to chemotherapy, hence the need to identify improved biomarkers to aid in both diagnosis and treatment modalities. This review summarises more recent research on the dysregulated miRNA expression profiles found in NHL, as well as the regulatory role and biomarker potential of cellular and circulating miRNAs found in tissue and serum, respectively. In addition, the emerging field of research focusing on miRNA single nucleotide polymorphisms (miRSNPs) in genes of the miRNA biogenesis pathway, in miRNA genes themselves, and in their target sites may provide new insights on gene expression changes in these genes. These miRSNPs may impact miRNA networks and have been shown to play a role in a host of different cancer types including haematological malignancies. With respect to NHL, a number of SNPs in miRNA-binding sites in target genes have been shown to be associated with overall survival.

Diagnostic Potential of Cell-Free and Exosomal MicroRNAs in the Identification of Patients with High-Risk Colorectal Adenomas

BACKGROUND

Although there is a growing interest in developing circulating microRNA (miRNA) as noninvasive diagnostic biomarkers for the detection of high-risk colorectal adenomas and early-stage CRCs, but the comparative diagnostic significance of serum vs. exosomal miRNAs remains unexplored.

METHODS

Based upon published literature, we performed an initial discovery step by investigating the expression of a miRNA panel in 20 normal colonic mucosa, 27 adenomas, and 19 CRC tissues. We performed subsequent validation by quantifying expression of candidate miRNAs in total serum and in exosomes from 26 adenoma patients and 47 healthy controls, and evaluated their clinical significance and potential diagnostic value in colorectal adenomas.

RESULTS

We observed that the expression of four miRNAs, miR-21, miR-29a, miR-92a, and miR-135b, was significantly higher in colorectal adenomas vs. normal colonic mucosa. During validation, expression of miR-21, miR-29a and miR-92a in serum was significantly higher in adenomas vs. healthy controls, significantly correlated with adenoma size and total adenoma number within the colorectum, and significantly discriminated patients with advanced adenomas. In contrast, although exosomal miR-21 and miR-29a levels in adenoma patients were significantly higher than those of healthy volunteers, only exosomal miR-21 significantly correlated with adenoma size and total adenoma number, and could discriminate patients with high-risk adenomas.

CONCLUSION

Compared to exosomal miRNAs, serum levels of miR-21, miR-29a and miR-92a are superior diagnostic biomarkers in patients with high-risk adenomatous polyps.

H19 Noncoding RNA, an Independent Prognostic Factor, Regulates Essential Rb-E2F and CDK8-β-Catenin Signaling in Colorectal Cancer

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High H19 expression in primary tumors is an independent predictor of short overall survival in CRC patients.

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RB1-E2F and CDK8-β-catenin signaling are essential in mediating the oncogenic activity of H19 in CRC.

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Combined analysis of H19 and its targets further improved the prediction power on overall survival of CRC patients.

Long noncoding RNAs (lncRNAs) are transcripts at least 200 nucleotides long that do not code for proteins. The clinical relevance of lncRNAs in colorectal cancer (CRC) is largely unknown. Here we identified that H19 expression in primary tumors is an independent prognostic predictor of poor prognosis of CRC patients and further proved its oncogenic role. To characterize the mechanisms, we profiled gene expression changes following H19 modulation in CRC cell lines and analyzed gene expression association in clinical datasets. Our data revealed important cancer-signaling pathways, including the RB1-E2F and the CDK8-β-catenin signaling, underlying H19 function.

The clinical significance of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC) remains largely unexplored. Here, we analyzed a large panel of lncRNA candidates with The Cancer Genome Atlas (TCGA) CRC dataset, and identified H19 as the most significant lncRNA associated with CRC patient survival. We further validated such association in two independent CRC cohorts. H19 silencing blocked G1-S transition, reduced cell proliferation, and inhibited cell migration. We profiled gene expression changes to gain mechanism insight of H19 function. Transcriptome data analysis revealed not only previously identified mechanisms such as Let-7 regulation by H19, but also RB1-E2F1 function and β-catenin activity as essential upstream regulators mediating H19 function. Our experimental data showed that H19 affects phosphorylation of RB1 protein by regulating gene expression of CDK4 and CCND1. We further demonstrated that reduced CDK8 expression underlies changes of β-catenin activity, and identified that H19 interacts with macroH2A, an essential regulator of CDK8 gene transcription. However, the relevance of H19-macroH2A interaction in CDK8 regulation remains to be experimentally determined. We further explored the clinical relevance of above mechanisms in clinical samples, and showed that combined analysis of H19 with its targets improved prognostic value of H19 in CRC.

Diagnostic Potential of Cell-Free and Exosomal MicroRNAs in the Identification of Patients with High-Risk Colorectal Adenomas

BACKGROUND

Although there is a growing interest in developing circulating microRNA (miRNA) as noninvasive diagnostic biomarkers for the detection of high-risk colorectal adenomas and early-stage CRCs, but the comparative diagnostic significance of serum vs. exosomal miRNAs remains unexplored.

METHODS

Based upon published literature, we performed an initial discovery step by investigating the expression of a miRNA panel in 20 normal colonic mucosa, 27 adenomas, and 19 CRC tissues. We performed subsequent validation by quantifying expression of candidate miRNAs in total serum and in exosomes from 26 adenoma patients and 47 healthy controls, and evaluated their clinical significance and potential diagnostic value in colorectal adenomas.

RESULTS

We observed that the expression of four miRNAs, miR-21, miR-29a, miR-92a, and miR-135b, was significantly higher in colorectal adenomas vs. normal colonic mucosa. During validation, expression of miR-21, miR-29a and miR-92a in serum was significantly higher in adenomas vs. healthy controls, significantly correlated with adenoma size and total adenoma number within the colorectum, and significantly discriminated patients with advanced adenomas. In contrast, although exosomal miR-21 and miR-29a levels in adenoma patients were significantly higher than those of healthy volunteers, only exosomal miR-21 significantly correlated with adenoma size and total adenoma number, and could discriminate patients with high-risk adenomas.

CONCLUSION

Compared to exosomal miRNAs, serum levels of miR-21, miR-29a and miR-92a are superior diagnostic biomarkers in patients with high-risk adenomatous polyps.

miRNA profiling of circulating EpCAM(+) extracellular vesicles: promising biomarkers of colorectal cancer

Cancer cells secrete small membranous extracellular vesicles (EVs) into their microenvironment and circulation. These contain biomolecules, including proteins and microRNAs (miRNAs). Both circulating EVs and miRNAs have received much attention as biomarker candidates for non-invasive diagnostics. Here we describe a sensitive analytical method for isolation and subsequent miRNA profiling of epithelial-derived EVs from blood samples of patients with colorectal cancer (CRC). The epithelial-derived EVs were isolated by immunoaffinity-capture using the epithelial cell adhesion molecule (EpCAM) as marker. This approach mitigates some of the specificity issues observed in earlier studies of circulating miRNAs, in particular the negative influence of miRNAs released by erythrocytes, platelets and non-epithelial cells. By applying this method to 2 small-scale patient cohorts, we showed that blood plasma isolated from CRC patients prior to surgery contained elevated levels of 13 EpCAM⁺-EV miRNAs compared with healthy individuals. Upon surgical tumour removal, the plasma levels of 8 of these were reduced (miR-16-5p, miR-23a-3p, miR-23b-3p, miR-27a-3p, miR-27b-3p, miR-30b-5p, miR-30c-5p and miR-222-3p). These findings indicate that the miRNAs are of tumour origin and may have potential as non-invasive biomarkers for detection of CRC. This work describes a non-invasive blood-based method for sensitive detection of cancer with potential for clinical use in relation to diagnosis and screening. We used the method to study CRC; however, it is not restricted to this disease. It may in principle be used to study any cancer that release epithelial-derived EVs into circulation.

Expression of serum miR-200a, miR-200b, and miR-200c as candidate biomarkers in epithelial ovarian cancer and their association with clinicopathological features

BACKGROUND

MicroRNAs (miRs) have been implicated in the etiology of various human cancers. The aim of this study was to investigate the association of the expression of three members--miR 200a, miR 200b, and miR 200c belonging to the miR-200 family with clinicopathological characteristics and their impact on the progression of epithelial ovarian cancer (EOC).

MATERIALS AND METHODS

Total RNA from serum was isolated by Trizol method, polyadenylated, and reverse transcribed into cDNA. Expression levels of miR-200a, miR-200b, and miR-200c were detected by using miRNA qRT-PCR. We measured miR expression in 70 serum samples of EOC patients with matched controls using U6 snRNA as a reference. Levels of miR expression was compared with distinct clinicopathological features.

RESULTS

Expression of miR-200a was found to be greater than six-fold (p = 0.01), miR-200b and miR-200c greater than three-fold (p = 0.01) in comparison with matched normal controls. Association of miRNA expression with clinicopathological factors and progression was statistically evaluated. The expression levels of miR-200a and miR-200c were found to be significantly associated with disease progression (p = 0.04 and p < 0.001, respectively). miR-200a overexpression was found be associated with tumor histology and stage. Patients with lymph node metastasis showed significant elevation of miR-200c (p = 0.006). The AUC in ROC curve also indicated that serum levels of miR-200a and miR-200c might be worthwhile as a diagnostic tool in the near future.

CONCLUSION

Our findings suggest that miR-200a, miR-200b, and miR-200c overexpressions are associated with the aggressive tumor progression and be recognized as reliable markers to predict the prognosis and survival in EOC patients.