Circulating MicroRNA Biomarkers for Lung Cancer Detection in East Asian Populations

Theoretical perspectives and clinical applications of non-coding RNA in lung cancer metastasis: a systematic review

Lung cancer is one of the deadliest malignancies worldwide, with distant metastasis being a major cause of death. However, the specific mechanisms of lung cancer metastasis remain unclear. NcRNAs, a widely present type of non-coding RNAs in the body, constitute about 98% of the human genome, lacking protein-coding capacity but involved in various cellular processes such as proliferation, apoptosis, invasion, and migration. Studies have shown that ncRNAs play a crucial role in the metastasis of lung cancer, although research in this area is limited. This review summarizes the biological origins and functions of ncRNAs, their specific roles and mechanisms in lung cancer metastasis, and discusses their potential for early screening and therapeutic applications in lung cancer. Furthermore, it outlines the challenges in translating basic advancements of ncRNAs in lung cancer metastasis into clinical practice.

Circulating MicroRNAs as Biomarkers for the Early Diagnosis of Lung Cancer and Its Differentiation from Tuberculosis

BACKGROUND

The differential diagnosis of tuberculosis (TB) and lung cancer (LC) is often challenging due to similar clinicopathological presentations when bacterial shedding is negative, which can lead to delays in treatment. In this study, we tested the potential of plasma-circulating microRNAs (miRNAs) for the early and differential diagnosis of TB and LC.

METHODS

We conducted a two-phase study: profiling 188 miRNAs in pooled plasma samples and validating 14 selected miRNAs in individual plasma samples from 68 LC patients, 38 pulmonary TB patients, and 41 healthy controls.

RESULTS

Twelve miRNAs were significantly elevated in LC patients compared to controls and TB patients, while two miRNAs were significantly elevated in TB patients compared to controls. ROC analysis demonstrated that miR-130b-3p, miR-1-3p, miR-423-5p, and miR-200a-3p had good discriminatory ability to distinguish LC patients (including those with stage I tumours) from healthy individuals and miR-130b-3p, miR-423-5p, miR-15b-5p, and miR-18b-5p effectively distinguished LC patients (including those with stage I tumours) from TB patients. Additionally, miR-18b-5p showed good discriminatory ability between SCLC and NSCLC patients.

CONCLUSIONS

Circulating miRNAs hold strong potential for the early detection of LC and for distinguishing LC from TB.

Current Evidence for a Lung Cancer Screening Program

Background

Lung cancer screening is still in an early phase compared to other cancer screening programs, despite its high lethality particularly when diagnosed late. Achieving early diagnosis is crucial to obtain optimal outcomes.

Summary

In this review, we will address the current evidence on lung cancer screening through low-dose computed tomography (LDCT) and its impact on mortality reduction, existing screening recommendations, patient eligibility criteria, screening frequency and duration, benefits and harms, cost-effectiveness and some insights on lung cancer screening implementation and adoption. Additionally, new non-imaging, noninvasive biomarkers with high diagnostic potential are also briefly highlighted.

Key Messages

LDCT screening in a prespecified population based on age and smoking history proved to reduce lung cancer mortality. Optimization of the target population and management of LDCT pitfalls can further improve lung cancer screening efficiency and cost-effectiveness. Novel screening technologies and biomarkers being studied can potentially be game-changers in lung cancer screening and diagnosis.

Metal-organic framework (MOF)-based biosensors for miRNA detection

MicroRNAs (miRNAs) play several crucial roles in the physiological and pathological processes of the human body. They are considered as important biomarkers for the diagnosis of various disorders. Thus, rapid, sensitive, selective, and affordable detection of miRNAs is of great importance. However, the small size, low abundance, and highly similar sequences of miRNAs impose major challenges to their accurate detection in biological samples. In recent years, metal-organic frameworks (MOFs) have been applied as promising sensing materials for the fabrication of different biosensors due to their distinctive characteristics, such as high porosity and surface area, tunable pores, outstanding adsorption affinities, and ease of functionalization. In this review, the applications of MOFs and MOF-derived materials in the fabrication of fluorescence, electrochemical, chemiluminescence, electrochemiluminescent, and photoelectrochemical biosensors for the detection of miRNAs and their detection principle and analytical performance are discussed. This paper attempts to provide readers with a comprehensive knowledge of the fabrication and sensing mechanisms of miRNA detection platforms.

A novel microRNA miR-4433a-3p as a potential diagnostic biomarker for lung adenocarcinoma

Background

Lung adenocarcinoma is one of the leading causes of cancer-related deaths because of the lack of early specific clinical indicators. MicroRNAs (miRNAs) have become the focus in lung cancer diagnosis. Further studies are required to explore miRNA expression in the serum of lung adenocarcinoma patients and their correlation with therapy and analyse specific messenger RNA targets to improve the specificity and sensitivity of early diagnosis.

Methods

The Toray 3D-Gene miRNA array was used to compare the expression levels of various miRNAs in the sera of patients with lung adenocarcinoma and healthy volunteers. Highly expressed miRNAs were selected for further analysis. To verify the screening results, serum and pleural fluid samples were analysed using qRT-PCR. Serum levels of the miRNAs and their correlation with the clinical information of patients with lung adenocarcinoma were analysed. The functions of miRNAs were further analysed using the Kyoto Encyclopedia of Gene and Genomes and Gene Ontology databases.

Results

Microarray analysis identified 60 and 50 miRNAs with upregulated and downregulated expressions, respectively, in the serum of patients with lung adenocarcinoma compared to those in healthy individuals. Using qRT-qPCR to detection of miRNAs expression in the serum or pleural effusion of patients with early and advanced lung adenocarcinoma, we found that miR-4433a-3p could be used as a diagnostic marker and therapeutic evaluation indicator for lung adenocarcinoma. Serum of miR-4433a-3p levels significantly correlated with the clinical stage. miR-4433a-3p may be more suitable than other tumour markers for the early diagnosis and evaluation of therapeutic effects in lung adenocarcinoma. miR-4433a-3p may affect tumour growth and metastasis by acting on target genes (PIK3CD, UBE2J2, ICMT, PRDM16 and others) and regulating tumour-related signalling pathways (MAPK signal pathway, Ras signalling pathway and others).

Conclusion

miR-4433a-3p may serve as a biomarker for the early diagnosis of lung adenocarcinoma and monitoring of therapeutic effects.

Mediation of association between benzo[a]pyrene exposure and lung cancer risk by plasma microRNAs: A Chinese case-control study

Epidemiologic studies have reported the positive relationship of benzo[a]pyrene (BaP) exposure with the risk of lung cancer. However, the mechanisms underlying the relationship is still unclear. Plasma microRNA (miRNA) is a typical epigenetic biomarker that was linked to environment exposure and lung cancer development. We aimed to reveal the mediation effect of plasma miRNAs on BaP-related lung cancer. We designed a lung cancer case-control study including 136 lung cancer patients and 136 controls, and measured the adducts of benzo[a]pyrene diol epoxide-albumin (BPDE-Alb) and sequenced miRNA profiles in plasma. The relationships between BPDE-Alb adducts, normalized miRNA levels and the risk of lung cancer were assessed by linear regression models. The mediation effects of miRNAs on BaP-related lung cancer were investigated. A total of 190 plasma miRNAs were significantly related to lung cancer status at Bonferroni adjusted P < 0.05, among which 57 miRNAs showed different levels with |fold change| > 2 between plasma samples before and after tumor resection surgery at Bonferroni adjusted P < 0.05. Especially, among the 57 lung cancer-associated miRNAs, BPDE-Alb adducts were significantly related to miR-17-3p, miR-20a-3p, miR-135a-5p, miR-374a-5p, miR-374b-5p, miR-423-5p and miR-664a-5p, which could in turn mediate a separate 42.2%, 33.0%, 57.5%, 36.4%, 48.8%, 32.5% and 38.2% of the relationship of BPDE-Alb adducts with the risk of lung cancer. Our results provide non-invasion biomarker candidates for lung cancer, and highlight miRNAs dysregulation as a potential intermediate mechanism by which BaP exposure lead to lung tumorigenesis.

Exploring Optimal Biomarker Sources: A Comparative Analysis of Exosomes and Whole Plasma in Fasting and Non-Fasting Conditions for Liquid Biopsy Applications

The study of liquid biopsy with plasma samples is being conducted to identify biomarkers for clinical use. Exosomes, containing nucleic acids and metabolites, have emerged as possible sources for biomarkers. To evaluate the effectiveness of exosomes over plasma, we analyzed the small non-coding RNAs (sncRNAs) and metabolites extracted from exosomes in comparison to those directly extracted from whole plasma under both fasting and non-fasting conditions. We found that sncRNA profiles were not affected by fasting in either exosome or plasma samples. Our results showed that exosomal sncRNAs were found to have more consistent profiles. The plasma miRNA profiles contained high concentrations of cell-derived miRNAs that were likely due to hemolysis. We determined that certain metabolites in whole plasma exhibited noteworthy concentration shifts in relation to fasting status, while others did not. Here, we propose that (1) fasting is not required for a liquid biopsy study that involves both sncRNA and metabolomic profiling, as long as metabolites that are not influenced by fasting status are selected, and (2) the utilization of exosomal RNAs promotes robust and consistent findings in plasma samples, mitigating the impact of batch effects derived from hemolysis. These findings advance the optimization of liquid biopsy methodologies for clinical applications.

Recent advances on high-efficiency of microRNAs in different types of lung cancer: a comprehensive review

Carcinoma of the lung is among the most common types of cancer globally. Concerning its histology, it is categorized as a non-small cell carcinoma (NSCLC) and a small cell cancer (SCLC) subtype. MicroRNAs (miRNAs) are a member of non-coding RNA whose nucleotides range from 19 to 25. They are known to be critical regulators of cancer via epigenetic control of oncogenes expression and by regulating tumor suppressor genes. miRNAs have an essential function in a tumorous microenvironment via modulating cancer cell growth, metastasis, angiogenesis, metabolism, and apoptosis. Moreover, a wide range of information produced via several investigations indicates their tumor-suppressing, oncogenic, diagnostic assessment, and predictive marker functions in different types of lung malignancy. miRNA mimics or anti-miRNAs can be transferred into a lung cancer cell, with possible curative implications. As a result, miRNAs hold promise as targets for lung cancer treatment and detection. In this study, we investigate the different functions of various miRNAs in different types of lung malignancy, which have been achieved in recent years that show the lung cancer-associated regulation of miRNAs expression, concerning their function in lung cancer beginning, development, and resistance to chemotherapy, also the probability to utilize miRNAs as predictive biomarkers for therapy reaction.

Small RNA Deep Sequencing of Circulating Small RNAs Discovers a Unique Panel of microRNAs as Feasible and Reliable Biomarkers of Non-Small Cell Lung Cancers in Northern Thailand

OBJECTIVE

This study aimed to assess the practicality and reliability of utilizing microRNAs (miRNAs) as a potential screening and diagnosing tool for non-small cell lung cancers (NSCLCs) in Northern Thailand.

METHODS

Small RNA sequencing and a literature review was performed to obtain a list of serum miRNA candidates. Serum levels of these selected miRNA candidates were measured in patients with NSCLC and healthy volunteers by real-time RT-PCR and receiver operating characteristic curve (ROC) were used to assess diagnostic performance.

RESULTS

Sequencing data revealed 148 known miRNAs and 230 novel putative miRNAs in serum samples; 19 serum miRNAs were significantly downregulated and 242 were upregulated. Seven miRNAs selected according to sequencing data and 11 miRNAs according to previous reports were evaluated in training cohort (45 lung cancer patients, 26 controls) and 6 miRNAs were found differentially expressed (p < 0.05, Mann Whitney U test) and associated (p < 0.05, Chi-square test) with NSCLC development. Further analysis and verification identified an optimal combination of 4 miRNAs composed of hsa-miR23a, hsa-miR26b, hsa-miR4488 and novel-130 to provide the optimal AUC of 0.901±0.034. Detection of serum miRNA by real-time RT-PCR showed good reproducibility with the coefficient of variation (CV) ≤ 4%. The optimal screening miRNAs panel was primarily identified through sequencing data of local patient population, thus indicating that the etiology of NSCLCs may differ from one population to other and thus require a unique panel of miRNAs for their identification.

CONCLUSION

Circulating miRNA is a feasible screening tool for NSCLCs. Nevertheless, populations with different lung cancer etiology may need to identify their own most suitable miRNA panel.

Circulating noncoding RNAs: promising biomarkers in liquid biopsy for the diagnosis, prognosis, and therapy of NSCLC

As the second most common malignant tumor in the world, lung cancer is a great threat to human health. In the past several decades, the role and mechanism of ncRNAs in lung cancer as a class of regulatory RNAs have been studied intensively. In particular, ncRNAs in body fluids have attracted increasing attention as biomarkers for lung cancer diagnosis and prognosis and for the evaluation of lung cancer treatment due to their low invasiveness and accessibility. As emerging tumor biomarkers in lung cancer, circulating ncRNAs are easy to obtain, independent of tissue specimens, and can well reflect the occurrence and progression of tumors due to their correlation with some biological processes in tumors. Circulating ncRNAs have a very high potential to serve as biomarkers and hold promise for the development of ncRNA-based therapeutics. In the current study, there has been extensive evidence that circulating ncRNA has clinical significance and value as a biomarker. In this review, we summarize how ncRNAs are generated and enter the circulation, remaining stable for subsequent detection. The feasibility of circulating ncRNAs as biomarkers in the diagnosis and prognosis of non-small cell lung cancer is also summarized. In the current systematic treatment of non-small cell lung cancer, circulating ncRNAs can also predict drug resistance, adverse reactions, and other events in targeted therapy, chemotherapy, immunotherapy, and radiotherapy and have promising potential to guide the systematic treatment of non-small cell lung cancer.

Definition of a new blood cell count score for early survival prediction for non-small cell lung cancer patients treated with atezolizumab: Integrated analysis of four multicenter clinical trials

Importance

Blood cell count test (BCT) is a robust method that provides direct quantification of various types of immune cells to reveal the immune landscape to predict atezolizumab treatment outcomes for clinicians to decide the next phase of treatment.

Objective

This study aims to define a new BCTscore model to predict atezolizumab treatment benefits in non-small lung cell cancer (NSCLC) patients.

Design, Setting, and Participants

This study analyzed four international, multicenter clinical trials (OAK, BIRCH, POPLAR, and FIR trials) to conduct post-hoc analyses of NSCLC patients undergoing atezolizumab (anti–PD-L1) single-agent treatment (n = 1,479) or docetaxel single-agent treatment (n = 707). BCT was conducted at three time points: pre-treatment (T1), the first day of treatment cycle 3 (T2), and first day of treatment cycle 5 (T3). Univariate and multivariate Cox regression analyses were conducted to identify early BCT biomarkers to predict atezolizumab treatment outcomes in NSCLC patients.

Main Outcomes and Measures

Overall survival (OS) was used as the primary end point, whereas progression-free survival (PFS) according to Response Evaluation Criteria in Solid Tumors (RECIST), clinical benefit (CB), and objective response rate (ORR) were used as secondary end points.

Results

The BCT biomarkers of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) at time point T3 and neutrophil-to-monocyte ratio (NMR) at time point T2 with absolute cutoff values of NLR_T3 = 5, PLR_T3 = 180, and NMR_T2 = 6 were identified as strong predictive biomarkers for atezolizumab (Ate)–treated NSCLC patients in comparison with docetaxel (Dtx)–treated patients regarding OS (BCTscore low risk: HR _Ate vs_{. Dtx} = 1.54 (95% CI: 1.04–2.27), P = 0.031; high risk: HR _Ate vs_{. Dtx} = 0.84 (95% CI: 0.62–1.12), P = 0.235). The identified BCTscore model showed better OS AUC in the OAK (AUC_12month = 0.696), BIRCH (AUC_12month = 0.672) and POPLAR+FIR studies (AUC_12month = 0.727) than that of each of the three single BCT biomarkers.

Conclusion and Relevance

The BCTscore model is a valid predictive and prognostic biomarker for early survival prediction in atezolizumab-treated NSCLC patients.

Unique circulating microRNA profiles in epidemic Kaposi's sarcoma

Background

Human herpesvirus 8 (HHV-8) causes Kaposi's sarcoma (KS). Kaposi sarcoma in HIV/AIDS patients is referred to as epidemic KS and is the most common HIV-related malignancy worldwide. The lack of a diagnostic assay to detect latent and early-stage disease has increased disease morbidity and mortality. Serum miRNAs have previously been used as potential biomarkers of normal physiology and disease. In the current study, we profiled unique serum miRNAs in patients with epidemic KS to generate baseline data to aid in developing a miRNA-based noninvasive biomarker assay for epidemic KS.

Methods

This was a comparative cross-sectional study involving 27 patients with epidemic KS and 27 HIV-positive adults with no prior diagnosis or clinical manifestation of KS. DNA and RNA were isolated from blood and serum collected from study participants. Nested PCR for circulating HHV-8 DNA was performed on the isolated DNA, whereas miRNA library preparation and sequencing for circulating miRNA were performed on the RNA samples. The miRge2 pipeline and EdgeR were used to analyse the sequencing data.

Results

Fifteen out of the 27 epidemic KS-positive subjects (55.6%) tested positive for HHV-8 DNA, whereas only 3 (11.1%) out of the 27 HIV-positive, KS-negative subjects tested positive for HHV-8 DNA. Additionally, we found a unique miRNA expression signature in 49 circulating miRNAs in epidemic KS subjects compared to subjects with no epidemic KS, with 41 miRNAs upregulated and 8 miRNAs downregulated. Subjects with latent KS infection had a differential upregulation of circulating miR-193a compared to HIV-positive, KS-negative subjects for whom circulating HHV-8 DNA was not detected. Further analysis of serum from epidemic KS patients revealed a miRNA signature according to KS tumor status and time since first HIV diagnosis.

Conclusions

This study reveals unique circulating miRNA profiles in the serum of patients with epidemic KS versus HIV-infected subjects with no KS, as well as in subjects with latent KS. Many of the dysregulated miRNAs in epidemic KS patients were previously reported to have crucial roles in KS infection and latency, highlighting their promising roles as potential biomarkers of latent or active KS infection.

Serum RNAs can predict lung cancer up to 10 years prior to diagnosis

Lung cancer (LC) prognosis is closely linked to the stage of disease when diagnosed. We investigated the biomarker potential of serum RNAs for the early detection of LC in smokers at different prediagnostic time intervals and histological subtypes. In total, 1061 samples from 925 individuals were analyzed. RNA sequencing with an average of 18 million reads per sample was performed. We generated machine learning models using normalized serum RNA levels and found that smokers later diagnosed with LC in 10 years can be robustly separated from healthy controls regardless of histology with an average area under the ROC curve (AUC) of 0.76 (95% CI, 0.68-0.83). Furthermore, the strongest models that took both time to diagnosis and histology into account successfully predicted non-small cell LC (NSCLC) between 6 and 8 years, with an AUC of 0.82 (95% CI, 0.76-0.88), and SCLC between 2 and 5 years, with an AUC of 0.89 (95% CI, 0.77-1.0), before diagnosis. The most important separators were microRNAs, miscellaneous RNAs, isomiRs, and tRNA-derived fragments. We have shown that LC can be detected years before diagnosis and manifestation of disease symptoms independently of histological subtype. However, the highest AUCs were achieved for specific subtypes and time intervals before diagnosis. The collection of models may therefore also predict the severity of cancer development and its histology. Our study demonstrates that serum RNAs can be promising prediagnostic biomarkers in an LC screening setting, from early detection to risk assessment.

Dose-dependent expression of extracellular microRNAs in HCT116 colorectal cancer cells exposed to high-dose-rate ionising radiation

Biomarkers of tumour response to radiotherapy may help optimise cancer treatment. The aim of the present study was to identify changes in extracellular microRNAs (miRNAs) as a biomarker of radiation-induced damage to human colorectal cancer cells. HCT116 cells were exposed to increasing doses of X-rays, and extracellular miRNAs were analysed by microarray. The results were correlated with the frequency of micronuclei. A total of 59 miRNAs with a positive correlation and 4 with a negative correlation between dose (up to 6 Gy) and extracellular miRNA expression were identified. In addition, for doses between 0 and 10 Gy, 12 miRNAs among those 59 miRNAs with a positive correlation were identified; for these extracellular miRNAs, a significantly positive correlation was observed between their expression and the frequency of micronuclei for doses up to 10 Gy. These results suggest that specific miRNAs may be considered as cell damage markers and may serve as secreted radiotherapy response biomarkers for colorectal cancer; however, the results must be further validated in serum samples collected from patients undergoing radiotherapy.

Identification of serum prognostic marker miRNAs and construction of microRNA-mRNA networks of esophageal cancer

Esophageal cancer is a common tumor of the digestive system with poor prognosis. This study was to gain a better understanding of the mechanisms involved in esophageal cancer and to identify new prognostic markers. We downloaded the esophageal cancer miRNA expression profile microarray data (GSE113740, GSE112264, GSE122497, GSE113486, and GSE106817) from the GEO database, extracted the esophageal cancer miRNA sequencing data from The Cancer Genome Atlas (TCGA) database, and then used a bioinformatics approach to select common differentially expressed miRNAs (DEMs). Differentially expressed genes (DEGs) were selected by predicting DEM target genes using the miRWalk database and intersecting with differential genes obtained from TCGA database for esophageal cancer. The STRING database was used to obtain protein-protein interaction (PPI) relationships to construct the DEM-DEG network. Furthermore, we selected core genes and core miRNAs associated with esophageal cancer prognosis by performing survival and univariate/multivariate COX analysis on DEMs and DEGs in the network and performed GSEA analysis on core genes alone, and finally the expression of the markers was verified by qPCR in esophageal cancer cell lines Eca109, SKGT-4 and normal esophageal epithelial cells HEEC. Nine DEMs were obtained, of which three were upregulated and six were downregulated, and 326 DEGs were obtained, of which 105 were upregulated and 221 were downregulated. Survival univariate/multivariate COX analysis revealed that five genes, ZBTB16, AQP4, ADCYAP1R1, PDGFD, and VIPR2, and two microRNAs, miR-99a-5p, and miR-508-5p, were related to esophageal cancer prognosis. GSEA analysis showed that the following genes may be involved in esophageal cancer prognosis: ZBTB16 may through the MTOR signaling pathway, AQP4 through the GNRH signaling pathway, ADCYAP1R1 through the PPAR signaling pathway, VIPR2 through the P53 signaling pathway and PDGFD through the PENTOSE-PHOSPHATE signaling pathway.

Relationship between diagnostic accuracy of microRNAs for NSCLC and number of combined microRNAs: an overview with meta-analysis

Objective: Several systematic reviews (SRs) have assessed the diagnostic accuracy of microRNAs (miRNAs) for NSCLC, and this overview aimed to assess the relationship between diagnostic accuracy of miRNAs for NSCLC and number of microRNAs combinations. Methods: Embase.com, PubMed, the Cochrane Library, and Web of Science were searched. The PRISMA-DTA was used for reporting quality evaluation. Meta-analysis was conducted to assess the pooled diagnostic accuracy of different miRNAs combinations, and subgroup analyses were performed based on the source of miRNA. Results: Fourteen SRs with 91 original studies were included. Three SRs had minimal reporting flaws, and 11 SRs had medium flaws. The pooled sensitivity and specificity were 0.76 and 0.80 for single miRNA, 0.80 and 0.81 for two miRNAs combined, 0.82 and 0.88 for three miRNAs combined, 0.88 and 0.92 for four miRNAs combined, 0.87 and 0.87 for five miRNAs combined, and 0.87 and 0.89 for six or more miRNAs combined. And miR-21 was mostly appeared. Subgroup analyses suggested that the serum-derived miRNA had the relatively best diagnostic value compared to other sources. Conclusions: Future studies should explore specific and serum-derived miRNAs in NSCLC and combine them to improve the diagnosis accuracy of NSCLC, which had great significance in economic efficiency.

Cancer Epigenetic Biomarkers in Liquid Biopsy for High Incidence Malignancies

Early alterations in cancer include the deregulation of epigenetic events such as changes in DNA methylation and abnormal levels of non-coding (nc)RNAs. Although these changes can be identified in tumors, alternative sources of samples may offer advantages over tissue biopsies. Because tumors shed DNA, RNA, and proteins, biological fluids containing these molecules can accurately reflect alterations found in cancer cells, not only coming from the primary tumor, but also from metastasis and from the tumor microenvironment (TME). Depending on the type of cancer, biological fluids encompass blood, urine, cerebrospinal fluid, and saliva, among others. Such samples are named with the general term "liquid biopsy" (LB). With the advent of ultrasensitive technologies during the last decade, the identification of actionable genetic alterations (i.e., mutations) in LB is a common practice to decide whether or not targeted therapy should be applied. Likewise, the analysis of global or specific epigenetic alterations may also be important as biomarkers for diagnosis, prognosis, and even for cancer drug response. Several commercial kits that assess the DNA promoter methylation of single genes or gene sets are available, with some of them being tested as biomarkers for diagnosis in clinical trials. From the tumors with highest incidence, we can stress the relevance of DNA methylation changes in the following genes found in LB: SHOX2 (for lung cancer); RASSF1A, RARB2, and GSTP1 (for lung, breast, genitourinary and colon cancers); and SEPT9 (for colon cancer). Moreover, multi-cancer high-throughput methylation-based tests are now commercially available. Increased levels of the microRNA miR21 and several miRNA- and long ncRNA-signatures can also be indicative biomarkers in LB. Therefore, epigenetic biomarkers are attractive and may have a clinical value in cancer. Nonetheless, validation, standardization, and demonstration of an added value over the common clinical practice are issues needed to be addressed in the transfer of this knowledge from "bench to bedside".

miRNAs in lung cancer. A systematic review identifies predictive and prognostic miRNA candidates for precision medicine in lung cancer

Lung cancer (LC) is the leading cause of cancer-related death worldwide and miRNAs play a key role in LC development. To better diagnose LC and to predict drug treatment responses we evaluated 228 articles encompassing 16,697 patients and 12,582 healthy controls. Based on the criteria of ≥3 independent studies and a sensitivity and specificity of >0.8 we found blood-borne miR-20a, miR-10b, miR-150, and miR-223 to be excellent diagnostic biomarkers for non-small cell LC whereas miR-205 is specific for squamous cell carcinoma. The systematic review also revealed 38 commonly regulated miRNAs in tumor tissue and the circulation, thus enabling the prediction of histological subtypes of LC. Moreover, theranostic biomarker candidates with proven responsiveness to checkpoint inhibitor treatments were identified, notably miR-34a, miR-93, miR-106b, miR-181a, miR-193a-3p, and miR-375. Conversely, miR-103a-3p, miR-152, miR-152-3p, miR-15b, miR-16, miR-194, miR-34b, and miR-506 influence programmed cell death-ligand 1 and programmed cell death-1 receptor expression, therefore providing a rationale for the development of molecularly targeted therapies. Furthermore, miR-21, miR-25, miR-27b, miR-19b, miR-125b, miR-146a, and miR-210 predicted response to platinum-based treatments. We also highlight controversial reports on specific miRNAs. In conclusion, we report diagnostic miRNA biomarkers for in-depth clinical evaluation. Furthermore, in an effort to avoid unnecessary toxicity we propose predictive biomarkers. The biomarker candidates support personalized treatment decisions of LC patients and await their confirmation in randomized clinical trials.

Ultrasensitive isothermal method to detect microRNA based on target-induced chain amplification reaction

We herein describe an ultrasensitive isothermal method to detect microRNA (miRNA) by utilizing target-induced chain amplification reaction (CAR). The hairpin probe (HP) employed in this strategy is designed to be opened upon binding to target miRNA. The exponential amplification reaction (EXPAR) template (ET) then binds to the exposed stem of HP and DNA polymerase (DP) promotes the extension reactions for both HP and ET, consequently producing intermediate double-stranded DNA product (IP) and concomitantly recycling target miRNA to open another intact HP. The IPs would produce a large number of target-mimicking probes (TMPs) and trigger probes (TPs) through the continuously repeated nicking and extension reactions at the two separated nicking sites within the IP. TMP triggers another CAR cycle by binding to intact HP as target miRNA did while TP promotes conventional EXPAR by independently binding to free ET. As a consequence of these interconnected reaction systems, a large number of final double-stranded DNA products (FPs) are produced, which can be monitored by measuring the fluorescent signal produced from duplex-specific fluorescent dye. Based on this unique design principle, the target miRNA was successfully determined down to even a single copy with high selectivity against non-specific miRNAs. The practical applicability of this method was also verified by reliably detecting target miRNA included in the total RNA extracted from the human cancer cell.

Circulating microRNA-145 as a diagnostic biomarker for non-small-cell lung cancer: A systemic review and meta-analysis

BACKGROUND

MicroRNAs (miRNAs), a class of small non-coding, highly stable RNAs, have been reported to have diagnostic value for variety types of cancers.

OBJECTIVES

To assess the diagnostic value of circulating miR-145 for non-small cell lung cancer (NSCLC) by using systemic review and meta-analysis.

METHODS

A systematic literature search was conducted in five databases until 20 February 2020 to identify diagnostic trials of miR-145 in the diagnosis of NSCLC. The quality of included studies was assessed by the QUADAS-2 tool with Review Manager 5.3, and the summary receiver operating characteristic (SROC) curve was plotted by STATA 13.1 software.

RESULTS

A total of 1394 patients from 11 data sets in trials (published in nine studies) were recruited. The area under the curve of the SROC was 0.83. According to the meta regression, the specimen selection was considered the source of heterogeneity, the SROC in serum (0.90 (95% CI 0.87, 0.92), the sensitivity was 0.84 (95% CI 0.79, 0.89), and the specificity was 0.80 (95% CI 0.71, 0.89)) was obviously higher than that in plasma (SROC=0.75).

CONCLUSION

Serum miR-145 might be served as a potentially useful biomarker for NSCLC diagnosis. However, due to the existing limited-quality research, more large-scale and multicenter studies are required for further verification.

The new horizon of liquid biopsy in sarcoma: the potential utility of circulating tumor nucleic acids

The diagnosis, treatment and prognosis of sarcoma are mainly dependent on tissue biopsy, which is limited in its ability to provide a panoramic view into the dynamics of tumor progression. In addition, effective biomarkers to monitor the progression and therapeutic response of sarcoma are lacking. Liquid biopsy, a recent technological breakthrough, has gained great attention in the last few decades. Nucleic acids (such as DNA, mRNAs, microRNAs, and long non-coding RNAs) that are released from tumors circulate in the blood of cancer patients and can be evaluated through liquid biopsy. Circulating tumor nucleic acids reflect the intertumoral and intratumoral heterogeneity, and thus liquid biopsy provides a noninvasive strategy to examine these molecules compared with traditional tissue biopsy. Over the past decade, a great deal of information on the potential utilization of circulating tumor nucleic acids in sarcoma screening, prognosis and therapy efficacy monitoring has emerged. Several specific gene mutations in sarcoma can be detected in peripheral blood samples from patients and can be found in circulating tumor DNA to monitor sarcoma. In addition, circulating tumor non-coding RNA may also be a promising biomarker in sarcoma. In this review, we discuss the clinical application of circulating tumor nucleic acids as blood-borne biomarkers in sarcoma.

Individual and joint contributions of genetic and methylation risk scores for enhancing lung cancer risk stratification: data from a population-based cohort in Germany

BACKGROUND

Risk stratification for lung cancer (LC) screening is so far mostly based on smoking history. This study aimed to assess if and to what extent such risk stratification could be enhanced by additional consideration of genetic risk scores (GRSs) and epigenetic risk scores defined by DNA methylation.

METHODS

We conducted a nested case-control study of 143 incident LC cases and 1460 LC-free controls within a prospective cohort of 9949 participants aged 50-75 years with 14-year follow-up. Lifetime smoking history was obtained in detail at recruitment. We built a GRS based on 31 previously identified LC-associated single-nucleotide polymorphisms (SNPs) and a DNA methylation score (MRS) based on methylation of 151 previously identified smoking-associated cytosine-phosphate-guanine (CpG) loci. We evaluated associations of GRS and MRS with LC incidence by logistic regression models, controlling for age, sex, smoking status, and pack-years. We compared the predictive performance of models based on pack-years alone with models additionally including GRS and/or MRS using the area under the receiver operating characteristic curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

RESULTS

GRS and MRS showed moderate and strong associations with LC risk even after comprehensive adjustment for smoking history (adjusted odds ratio [95% CI] comparing highest with lowest quartile 1.93 [1.05-3.71] and 5.64 [2.13-17.03], respectively). Similar associations were also observed within the risk groups of ever and heavy smokers. Addition of GRS and MRS furthermore strongly enhanced LC prediction beyond prediction by pack-years (increase of optimism-corrected AUC among heavy smokers from 0.605 to 0.654, NRI 26.7%, p = 0.0106, IDI 3.35%, p = 0.0036), the increase being mostly attributable to the inclusion of MRS.

CONCLUSIONS

Consideration of MRS, by itself or in combination with GRS, may strongly enhance LC risk stratification.

Non-invasive Detection of Exosomal MicroRNAs via Tethered Cationic Lipoplex Nanoparticles (tCLN) Biochip for Lung Cancer Early Detection

Circulating microRNAs carried by exosomes have emerged as promising diagnostic biomarkers for cancer because of their abundant amount and remarkable stability in body fluids. Exosomal microRNAs in blood are typically quantified using the RNA isolation-qRT-PCR workflow, which cannot distinguish circulating microRNAs secreted by cancer cells from those released by non-tumor cells, making it potentially less sensitive in detecting cancer-specific microRNA biomarkers. We have developed a sensitive and simple tethered cationic lipoplex nanoparticles (tCLN) biochip to detect exosomal microRNAs in human sera. The tCLN biochip allows the discrimination of tumor-derived exosomes from their non-tumor counterparts, and thus achieves higher detection sensitivity and specificity than qRT-PCR. We have demonstrated the clinical utility of the tCLN biochip in lung cancer diagnosis using sera from normal controls, therapy-naive early stage and late stage non-small cell lung cancer (NSCLC) patients. Total five microRNAs (miR-21, miR-25, miR-155, miR-210, and miR-486) were selected as the biomarkers. Each microRNA biomarker measured by tCLN assay showed higher sensitivity and specificity in lung cancer detection than that measured by qRT-PCR. When all five microRNAs were combined, the tCLN assay distinguished normal controls from all NSCLC patients with sensitivity of 0.969, specificity of 0.933 and AUC of 0.970, and provided much better diagnostic accuracy than qRT-PCR (sensitivity = 0.469, specificity = 1.000, AUC = 0.791). Remarkably, the tCLN assay achieved absolute sensitivity and specificity in discriminating early stage NSCLC patients from normal controls, demonstrating its great potential as a liquid biopsy assay for lung cancer early detection.

Non-coding RNA profile in lung cancer

Lung cancer is the most frequently diagnosed malignancy and the leading source of cancer-associated mortality. This kind of cancer has heterogeneous nature and is divided into two broad classes of small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). In addition to aberrant expression of several signaling pathways and oncogenes, lung cancer is associated with dysregulation of expression of non-coding RNAs including both long non-coding RNAs (lncRNAs) and miRNAs. These aberrantly expressed transcripts are putative therapeutic targets and diagnostic/ prognostic markers. Integrative assessment of expression of lncRNAs, miRNAs and mRNAs has led to construction of competing endogenous RNA networks in which several lncRNAs act as molecular sponges to inhibit regulatory function of miRNAs on mRNAs. Notably, some of these networks seem to have subtype-specific functions in lung cancer. In this review, we summarize recent findings about the importance of these networks in the pathogenesis of lung cancer and provide a list of onco-miRNAs, tumor suppressor miRNAs, oncogenic lncRNAs and tumor suppressor lncRNAs based on their roles in the carcinogenic process in lung cancer.

Clinical applications of liquid biopsies for early lung cancer detection

Over the past decade, the clinical utility of liquid biopsies in lung cancer has drawn increasing attention. Having been successfully applied in targeted therapy for late stage lung cancer, liquid biopsies are being further investigated regarding their potential role for early detection of lung cancer. Novel biomarkers with high sensitivity and specificity are crucial for identifying patients at early stages as well as for monitoring high-risk populations. A variety of bodily fluids (such as plasma, serum, and sputum) and biomarkers (such as cfDNA, CTCs, gene methylation, and miRNA) have been investigated for their potential role in the diagnosis of lung cancer. In this review, we summarize recent advances in circulating biomarkers regarding the early detection of lung cancer and discuss their potential applications and challenges in clinical settings.

One DNA circle capture probe with multiple target recognition domains for simultaneous electrochemical detection of miRNA-21 and miRNA-155

In this work, a novel DNA circle capture probe with multiple target recognition domains was designed to develop an electrochemical biosensor for ultrasensitive detection of microRNA-21 (miRNA-21) and miRNA-155 simultaneously. The DNA circle capture probe was anchored at the top of the tetrahedron DNA nanostructure (TDN) to simultaneously recognize miRNA-21 and miRNA-155 through multiple target recognition domains under the assistance of Helper strands, which could trigger mimetic proximity ligation assay (mPLA) for capturing the beacons ferrocene (Fc)-A1 and methylene blue (MB)-A2 to achieve multiple miRNAs detection. In this way, the local reaction concentration could be enhanced and avoid the interference of various capture probes compared with the traditional multiplexed electrochemical biosensor with the use of different capture probes, resulting in the significantly improvement of detection sensitivity. As a result, this proposed biosensor showed wide linearity ranging from 0.1 fM to 10 nM with detection limits of miRNA-21 and miRNA-155 as 18.9 aM and 39.6 aM respectively, which also could be applied in the simultaneously detection of miRNA-21 and miRNA-155 from cancer cell lysates. The present strategy paved a new path in the design of capture probes for achieving more efficient and sensitive multiple biomarkers detections and possessed the potential applications in clinical diagnostic of diseases.