Fu-Bing Wang

Liquid Biopsy of Hepatocellular Carcinoma: Circulating Tumor-Derived Biomarkers

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide due to latent liver disease, late diagnosis, and nonresponse to systemic treatments. Till now, surgical and/or biopsy specimens are still generally used as a gold standard by the clinicians for clinical decision-making. However, apart from their invasive characteristics, tumor biopsy only mirrors a single spot of the tumor, failing to reflect current cancer dynamics and progression. Therefore, it is imperative to develop new diagnostic strategies with significant effectiveness and reliability to monitor high-risk populations and detect HCC at an early stage. In the past decade, the potent utilities of “liquid biopsy” have attracted intense concern and were developed to evaluate cancer progression in several clinical trials. “Liquid biopsies” represent a series of noninvasive tests that detect cancer byproducts easily accessible in peripheral blood, mainly including circulating tumor cells (CTCs) and cell-free nucleic acids (cfNAs) that are shed into the blood from the tumor sites. In this review, we focus on the recent developments in the field of “liquid biopsy” as well as the diagnostic and prognostic significance of CTCs and cfNAs in HCC patients.

Quantitative and Qualitative Analysis of Circulating Cell-Free DNA Can Be Used as an Adjuvant Tool for Prostate Cancer Screening: A Meta-Analysis

As part of “liquid biopsy,” lots of literature indicated the potential diagnostic value of circulating cell-free DNA (cfDNA) in the management of prostate cancer (PCa). However, the literature on the accuracy of cfDNA detection in PCa has been inconsistent. Hence, we performed this meta-analysis to assess the diagnostic value of cfDNA in PCa. A total of 19 articles were included in this analysis according to the inclusion and exclusion criteria. We then investigated two main subgroups in this meta-analysis, including qualitative analysis of abnormal level of cfDNA and qualitative analysis of single-gene methylation alterations. Overall, the results of quantitative analysis showed sensitivity of 0.73 (95% CI, 0.62–0.82) and specificity of 0.80 (95% CI, 0.70–0.87), with an area under the curve (AUC) of 0.83 (95% CI, 0.80–0.86). For qualitative assessment, the values were 0.34 (95% CI, 0.22–0.48), 0.99 (95% CI, 0.97–1.00), and 0.91 (95% CI, 0.88–0.93), respectively. Our results suggest the pooled specificity of each subgroup is much higher than the specificity of prostate-specific antigen (PSA). However, they are not recommended for PCa screening alone, because their sensitivities are not higher than the conventional serum biomarkers PSA. We conclude that analysis of cfDNA can be used as an adjuvant tool for PCa screening.

Circulating microRNAs as novel biomarkers in the diagnosis of prostate cancer: a systematic review and meta-analysis

BackgroundThe diagnostic value of circulating microRNAs (miRNAs) detection in prostate cancer (PC) patients is currently under debate. Thus, we performed this meta-analysis of published literature to systematically evaluate the diagnostic potential of circulating miRNAs in PC.MethodsEligible studies were searched in PubMed, Embase and Chinese National Knowledge Infrastructure databases. Sensitivity and specificity were pooled using a random-effects model and were used to plot the summary receiver operator characteristic (SROC) curve. All analyses were performed using the Stata 13.0 software and Meta-Disc 1.4 for windows.ResultsA total of ten articles were included for the meta-analysis according to the inclusion criteria. The pooled results based on all included studies showed circulating miRNAs have a relatively good diagnostic performance, with a sensitivity of 0.74, a specificity of 0.71 and an area under SROC curve (AUC) of 0.77 in indiscriminating PC from controls. Furthermore, meta-regression and subgroup analyses indicate that multiple circulating miRNAs detection displayed a better diagnostic performance than single one, with an AUC rising from 0.75 to 0.81. Additional interesting finding was that Caucasian-based circulating miRNAs assays could reach a higher accuracy compared with non-Caucasian-based one for PC with the p value of 0.0378.ConclusionOur results confirmed the potential use of circulating miRNAs in the early diagnosis of PC, especially the combination of multiple circulating miRNAs. However, large-scale prospective studies are still needed to further validate our findings.

Down-regulation of miR-199b-5p is correlated with poor prognosis for breast cancer patients

OBJECTIVES The purpose of the present study was to evaluate the prognostic value of miR-199b-5p in breast cancer patients, as well as explore its effects on breast cancer cells. METHODS The expression level of miR-199b-5p in breast cancer tissues and paired non-cancerous tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Chi-square test was used to evaluate the relationship between miR-199b-5p expression and clinical parameters. Besides, overall survival analysis was carried out with Kaplan-Meier curve with log rank test, and the prognostic value of miR-199b-5p in breast cancer was evaluated by cox regression model. In addition, MTT and transwell assays in vitro were used to estimate the effects of miR-199b-5p on breast cancer cells. RESULTS MiR-199b-5p was down-regulated in breast cancer tissues, compared with adjacent normal tissues (P<0.05). Moreover, its decreased level was significantly correlated with advanced TNM stage (P=0.008) and positive lymph node metastasis (P=0.013). Cell experiments suggested that miR-199b-5p could regulate proliferation and invasion of breast cancer cells. In addition, we found that breast cancer patients with low miR-199b-5p expression level had poorer overall survival than those with high level (log rank test, P=0.021). MiR-199b-5p was an independent prognostic factor for breast cancer patients (HR=2.318, 95%CI=1.086-4.949, P=0.030). CONCLUSION Down-regulated miR-199b-5p in breast cancer patients is associated with malignant clinical characteristics. MiR-199b-5p may be a potential prognostic biomarker for breast cancer.

Tumor-Derived Exosomal Long Noncoding RNAs as Promising Diagnostic Biomarkers for Prostate Cancer

Background/Aims: Exosomal circulating long non-coding RNAs (lncRNAs) in blood are emerging as clinically useful and non-invasive biomarkers for tumor diagnosis. However, normal cells can also secrete exosomes, so it is a prerequisite to obtain tumor-derived exosomes for better understanding of their diagnostic impacts in cancer. In this study, a dual-antibody-functionalized immunoaffinity system was established to isolate exosomes and investigate their lncRNAs expression pattern and clinical significance in prostate cancer (PCa). Methods: A commercially available kit was used to isolate total exosomes, which were then purified by a dual-antibody-functionalized immunoaffinity system. RT-qPCR was performed to detect the expression of exosomal lncRNAs. Receiver operating characteristic (ROC) curves were plotted to assess the diagnostic value. Results: Expression levels of two lncRNAs in tumor-derived exosomes were significantly higher than those in total exosomes. The levels of SAP30L-AS1 were upregulated in benign prostatic hyperplasia (BPH), and SChLAP1 levels were significantly higher in PCa than in BPH and healthy individuals. The area under the ROC curve indicated that SAP30L-AS1 and SChLAP1 had adequate diagnostic value to distinguish PCa from controls. Two lncRNAs separately combined with prostate specific antigen (PSA) possessed a moderate ability for discrimination. SAP30L-AS1 expression level was related to PSA values and tumor invasion. SChLAP1 expression was significantly higher in patients with higher Gleason scores, and was also effective in differentiating between BPH and PCa when the concentration of PSA was in the gray zone. Conclusion: The isolation of tumor-derived exosomes by dual-antibody-functionalized immunoaffinity systems and detection of their lncRNAs in plasma may lead to the identification of suitable biomarkers, with potential diagnostic utility.

Association between Polymorphisms in MicroRNAs and Risk of Urological Cancer: A Meta-Analysis Based on 17,019 Subjects

Accumulating evidence has demonstrated that some single nucleotide polymorphisms (SNPs) existing in miRNAs correlate with the susceptibility to urological cancers. However, a clear consensus still not reached due to the limited statistical power in individual study. Thus, we concluded a meta-analysis to systematically evaluate the association between microRNA SNPs and urological cancer risk. Eligible studies were collected from PubMed, Embase, Web of Science, and CNKI databases. Pooled odds ratio (OR) and corresponding 95% confidence interval (95% CI) were calculated to assess the strength of the relationships between three SNPs (miR-196a2, C>T rs11614913; miR-146a, G>C rs2910164; and miR-499, A>G rs3746444) and the risk of urological cancers. In addition, the stability of our analysis was evaluated by publication bias, sensitivity and heterogeneity analysis. Overall, a total of 17,019 subjects from 14 studies were included in this meta-analysis. We found that CT (miR-196a2, C>T rs11614913) was a risk factor for renal cell carcinoma (CT vs. CC: OR = 1.72, 95%CI = 1.05–2.80, P = 0.03, I2 = 66%), especially in Asian population (CT vs. CC: OR = 1.17, 95%CI = 1.04–1.32, P < 0.01, I2 = 0%). miR-146a G>C rs2910164 was a protective factor of urological cancers (C vs. G: OR = 0.87, 95%CI = 0.81–0.93, P < 0.01, I2 = 0%), especially for bladder cancer. miR-499 A>G rs3746444 was correlated with an increased risk of urological cancers, specifically in Asian population. In conclusion, our meta-analysis suggests that polymorphisms in microRNAs, miR-196a2, C>T rs11614913, miR-146a G>C rs2910164 and miR-499 A>G rs3746444, may be associated with the development of urological cancers and the risks mainly exist in Asian populations.

Subtractive Cell-SELEX Selection of DNA Aptamers Binding Specifically and Selectively to Hepatocellular Carcinoma Cells with High Metastatic Potential

Relapse and metastasis are two key risk factors of hepatocellular carcinoma (HCC) prognosis; thus, it is emergent to develop an early and accurate detection method for prognostic evaluation of HCC after surgery. In this study, we sought to acquire oligonucleotide DNA aptamers that specifically bind to HCC cells with high metastatic potential. Two HCC cell lines derived from the same genetic background but with different metastatic potential were employed: MHCC97L (low metastatic properties) as subtractive targets and HCCLM9 (high metastatic properties) as screening targets. To mimic a fluid combining environment, initial DNA aptamers library was firstly labelled with magnetic nanoparticles using biotin-streptavidin system and then applied for aptamers selection. Through 10-round selection with subtractive Cell-SELEX, six aptamers, LY-1, LY-13, LY-46, LY-32, LY-27/45, and LY-7/43, display high affinity to HCCLM9 cells and do not bind to MHCC97L cells, as well as other tumor cell lines, including breast cancer, lung cancer, colon adenocarcinoma, gastric cancer, and cervical cancer, suggesting high specificity for HCCLM9 cells. Thus, the aptamers generated here will provide solid basis for identifying new diagnostic targets to detect HCC metastasis and also may provide valuable clues for developing new targeted therapeutics.

Meta-analysis of the prognostic value of abnormally expressed lncRNAs in hepatocellular carcinoma

Many long noncoding RNAs (lncRNAs) have been reported to be abnormally expressed in hepatocellular carcinoma (HCC), and may have the potential to serve as prognostic markers. In this study, a meta-analysis was conducted to systematically evaluate the prognostic value of various lncRNAs in HCC. Eligible literatures were systematically collected from PubMed, Embase, Web of Science, and Cochrane Library (up to December 30, 2015). The main outcomes including overall survival, relapse-free survival, and disease-free survival were analyzed. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated using random- or fixed-effects models. A total of 2,991 patients with HCC in People’s Republic of China from 27 studies were included in the analysis. The level of lncRNAs showed a significant association with clinical outcomes. Abnormally elevated lncRNA transcription level predicted poor overall survival (HR: 1.68, 95% CI: 1.20–2.34, P=0.002; I2=75.5%, P=0.000) and relapse-free survival (HR: 2.08, 95% CI: 1.65–2.61, P<0.001; I2=24.0%, P=0.215), while no association was observed with disease-free survival of HCC patients (HR: 1.39, 95% CI: 0.51–3.78, P=0.524; I2=81.3%, P=0.005). Subgroup analysis further showed that lncRNA transcription level was significantly associated with tumor size (relative risk [RR]: 1.19, 95% CI: 1.01–1.39, P=0.035), microvascular invasion (RR: 1.44, 95% CI: 1.10–1.89, P=0.009), and portal vein tumor thrombus (RR: 1.50, 95% CI: 1.03–2.20, P=0.036). Publication bias and sensitivity analysis further confirmed the stability of our results. Our present meta-analysis indicates that abnormal lncRNA transcription level may serve as a promising indicator for prognostic evaluation of patients with HCC in People’s Republic of China.

A miRNA Combination as Promising Biomarker for Hepatocellular Carcinoma Diagnosis: A Study Based on Bioinformatics Analysis

Background: miRNAs dysregulate in hepatocellular carcinoma (HCC), showing promise for diagnostic biomarkers which may be found through exploration of differentially expressed miRNAs when comparing HCC and normal liver tissues. Materials and Methods: In the present research, candidate miRNAs were selected and verified using screening dataset GSE12717 and training dataset GSE10694, respectively. A miRNA combination was constructed using stepwise logistic regression analysis and validated using two datasets GSE74618 and TCGA. Target genes of miRNAs in the combination were obtained using a miRNA target gene prediction database. Functional analysis was conducted using an online tool DAVID. We also analyzed the mRNA-Seq data of project LIHC from TCGA to identify the hub target genes of the miRNAs. Results: A miRNA combination, which is composed of hsa-miR-221 and hsa-miR-29c was defined in this study. The miRNA combination is more effective in discriminating HCC patients from normal individuals than individual miRNAs. Additionally, the combined miRNAs showed a lower misdiagnosis rate than AFP in HCC diagnosis. In terms of the functional analysis, a total of 27 target genes of hsa-miR-221 and 96 target genes of hsa-miR-29c were obtained. Among which, INSIG1 was the common target of the two miRNAs. It was also found that both previously mentioned miRNAs played important roles in the regulation of transcription, cell proliferation, and involvement in cancer-related pathways. Lastly, 2 hub target genes of hsa-miR-221 and 16 hub target genes of hsa-miR-29c were obtained. Conclusion: We established a miRNA combination as a promising tool for HCC diagnosis, and the target genes we predicted provide possible points of penetration for researching these two miRNAs in HCC.

MiR-139 in digestive system tumor diagnosis and detection: Bioinformatics and meta-analysis

BACKGROUND Accumulating evidence has indicated that microRNAs play important roles in the initiation and progression of digestive system tumors. However, previous studies suggest that the accuracy of miRNA detection in digestive system tumors was inconsistent. METHODS The candidate miRNAs were obtained from The Cancer Genome Atlas (TCGA). Meta-analysis was performed to evaluate the diagnostic value of these miRNAs in digestive system tumors. Furthermore, the potential target genes of the miRNAs were predicted and assessed with functional analysis. RESULTS According to TCGA data, miR-139 was a common biomarker of digestive system tumors. It was markedly reduced in tumor tissues as compared with non-cancerous tissues in digestive system tumors. In the meta-analysis, the pooled diagnostic odds ratio (DOR) and AUC was 57.51 (95% CI: 14.25-232.04) and 0.96 (95% CI: 0.94-0.97), respectively. Furthermore, the overall sensitivity and specificity was 0.89 (95% CI: 0.73-0.96) and 0.91 (95% CI: 0.75-0.97), respectively. The diagnostic value of tissue miR-139 was higher than the diagnostic value of blood miR-139. In particular, miR-139 was a superior marker for distinguishing colorectal cancer. CONCLUSION miR-139 could be a potential biomarker for diagnosis of digestive system tumors especially colorectal cancer.