An ultrasensitive method for detecting mutations from short and rare cell-free DNA

Circulating tumor DNA (ctDNA) was short and rare, making the detection performance of the current targeted sequencing methods unsatisfying. We developed the One-PrimER Amplification (OPERA) system and examined its performance in detecting mutations of low variant allelic frequency (VAF) in various samples with short-sized DNA fragments. In cell line-derived samples containing sonication-sheared DNA fragments with 50-150 bp, OPERA was capable of detecting mutations as low as 0.0025% VAF, while CAPP-Seq only detected mutations of >0.03% VAF. Both single nucleotide variant and insertion/deletion can be detected by OPERA. In synthetic fragments as short as 80 bp with low VAF (0.03%-0.1%), the detection sensitivity of OPERA was significantly higher compared to that of droplet digital polymerase chain reaction. The error rate was 5.9×10-5 errors per base after de-duplication in plasma samples collected from healthy volunteers. By suppressing "single-strand errors", the error rate can be further lowered by >5 folds in EGFR T790M hotspot. In plasma samples collected from lung cancer patients, OPERA detected mutations in 57.1% stage I patients with 100% specificity and achieved a sensitivity of 30.0% in patients with tumor volume of less than 1 cm3. OPERA can effectively detect mutations in rare and highly-fragmented DNA.

Stable LiF-Rich Electrode-Electrolyte Interface toward High-Voltage and High-Energy-Density Lithium Metal Solid Batteries

Lithium-rich layered oxide (LRLO) materials have attracted significant attention due to their high specific capacity, low cost, and environmental friendliness. However, owing to its unique capacity activation mechanism, the release of lattice oxygen during the first charge process leads to a series of problems, such as severe voltage decay, poor cycle stability, and poor rate performance. Herein, a fluorinated quasi-solid-state electrolyte (QSSE) via a simple thermal polymerization method toward lithium metal batteries with LRLO materials is reported. The well-designed QSSE exhibits an ionic conductivity of 6.4 × 10^-4 S cm^-1 at 30 °C and a wide electrochemical stable window up to 5.6 V. Most importantly, XPS spectra demonstrate the generation of a LiF-rich electrode-electrolyte interface (EEI), where the in situ generated LiF provides strong protection against the structural degradation of LRLO materials and directs the uniform plating/stripping behaviors of lithium-ions to inhibit the formation of lithium dendrites. As a result, LRLO/QSSE/Li batteries exhibit excellent rate performance and demonstrate a large initial capacity for 209.7 mA h g^-1 with a capacity retention of 80.8% after 200 cycles at 0.5C. This work provides a new insight for the LiF-rich EEI design of safe, high-performance quasi-solid-state lithium metal batteries.

Regulation of probe density on upconversion nanoparticles enabling high-performance lateral flow assays

Upconversion nanoparticles (UCNPs)-based fluorescence probes have shown great potential in point-of-care testing (POCT) applications, due to UCNPs' features of high photostability and background-free fluorescence. Ceaseless improvements of UCNPs-probes have been carried out to increase detection sensitivity and to broaden detection range of UCNPs-based POCT. In this paper, we optimized UCNPs-probes by regulating probe density. The optimization was verified by a traditional lateral flow assay (LFA) platform for C-reactive protein (CRP) detection. Further, the optimized UCNPs-LFA integrating with a home-made benchtop fluorescence analyzer holds the capability to achieve high-performance POCT. Finally, nearly a 20 times sensitivity enhancement with a limit of detection of 0.046 ng/mL and a broad detection range of 0.2-300 ng/mL for CRP detection was obtained. Moreover, the optimized UCNPs-LFA was applied to detecting CRP in clinical serum samples and the detection results were consistent with the clinical test, validating its clinical practicability. The proposed optimization method is also expected to optimize other nanoparticles-based bio-probes for wider POCT application.

Integrative Serum Metabolic Fingerprints Based Multi-Modal Platforms for Lung Adenocarcinoma Early Detection and Pulmonary Nodule Classification

Identification of novel non-invasive biomarkers is critical for the early diagnosis of lung adenocarcinoma (LUAD), especially for the accurate classification of pulmonary nodule. Here, a multiplexed assay is developed on an optimized nanoparticle-based laser desorption/ionization mass spectrometry platform for the sensitive and selective detection of serum metabolic fingerprints (SMFs). Integrative SMFs based multi-modal platforms are constructed for the early detection of LUAD and the classification of pulmonary nodule. The dual modal model, metabolic fingerprints with protein tumor marker neural network (MP-NN), integrating SMFs with protein tumor marker carcinoembryonic antigen (CEA) via deep learning, shows superior performance compared with the single modal model Met-NN (p < 0.001). Based on MP-NN, the tri modal model MPI-RF integrating SMFs, tumor marker CEA, and image features via random forest demonstrates significantly higher performance than the clinical models (Mayo Clinic and Veterans Affairs) and the image artificial intelligence in pulmonary nodule classification (p < 0.001). The developed platforms would be promising tools for LUAD screening and pulmonary nodule management, paving the conceptual and practical foundation for the clinical application of omics tools.

Comparative analysis of QS3D versus droplet digital PCR for quantitative measures of EGFR T790M mutation from identical plasma

Objectives

The capacity of QuantStudio™ 3D (QS3D) and droplet digital PCR (dPCR) for the detection of plasma Epidermal Growth Factor Receptor (EGFR) mutations have been widely reported. Few comparative studies on the quantitative test of the identical DNA material, however, are carried out. Here we compared the performance of the two methods in detecting EGFR T790M mutation in cell-free DNA (cfDNA) from the same lung cancer patients.

Methods

We recruited 72 non-small cell lung cancer (NSCLC) patients who initially respond to tyrosine kinase inhibitor treatment but subsequently developed resistance. Two tubes of 10mL anticoagulant blood were collected and cfDNA was isolated from plasma. Identical cfDNA samples were analyzed for T790M mutation using QS3D and droplet dPCR in parallel.

Results

T790M mutation was detected in 15 and 21 cfDNA samples by QS3D and droplet digital PCR, respectively. The 6 discordant samples showed low mutation abundance (∼0.1%) and the discrepancy is caused by the stricter threshold settings for QS3D dPCR. The overall agreement between the two methods was 91.7% (66/72). The median allele frequencies for QS3D dPCR and droplet dPCR to detect T790M mutation was 2.01% and 2.62%, respectively. There was no significance in mutation abundance detected by both methods. Both methods are highly correlated with allele frequencies and copy numbers in T790M wild type and mutant, with R² of 0.98, 0.92 and 0.95, respectively.

Conclusion

Our study demonstrated that QS3D dPCR are highly consistent with droplet PCR for quantitative determination of EGFR T790M mutation in plasma cfDNA.

Integrated microfluidic single-cell immunoblotting chip enables high-throughput isolation, enrichment and direct protein analysis of circulating tumor cells

Effective capture and analysis of a single circulating tumor cell (CTC) is instrumental for early diagnosis and personalized therapy of tumors. However, due to their extremely low abundance and susceptibility to interference from other cells, high-throughput isolation, enrichment, and single-cell-level functional protein analysis of CTCs within one integrated system remains a major challenge. Herein, we present an integrated multifunctional microfluidic system for highly efficient and label-free CTC isolation, CTC enrichment, and single-cell immunoblotting (ieSCI). The ieSCI-chip is a multilayer microfluidic system that combines an inertia force-based cell sorter with a membrane filter for label-free CTC separation and enrichment and a thin layer of a photoactive polyacrylamide gel with microwell arrays at the bottom of the chamber for single-cell immunoblotting. The ieSCI-chip successfully identified a subgroup of apoptosis-negative (Bax-negative) cells, which traditional bulk analysis did not detect, from cisplatin-treated cells. Furthermore, we demonstrated the clinical application of the ieSCI-chip with blood samples from breast cancer patients for personalized CTC epithelial-to-mesenchymal transition (EMT) analysis. The expression level of a tumor cell marker (EpCAM) can be directly determined in isolated CTCs at the single-cell level, and the therapeutic response to anticancer drugs can be simultaneously monitored. Therefore, the ieSCI-chip provides a promising clinical translational tool for clinical drug response monitoring and personalized regimen development.

A large-scale, multicentered trial evaluating the sensitivity and specificity of digital PCR versus ARMS-PCR for detecting ctDNA-based EGFR p.T790M in non-small-cell lung cancer patients

Background

Developing liquid biopsy technology with higher sensitivity and specificity especially for low-frequency mutations remains crucial. This study demonstrated superior performance of the newly developed digital PCR (dPCR) kit for ctDNA-based EGFR p.T790M detection in metastatic non-small-cell lung cancer (NSCLC) against ARMS-PCR.

Methods

This large-scale, multi-centered diagnostic study recruited 1,045 patients including 1,029 patients diagnosed with advanced NSCLC and 16 patients with specific samples between April 1^st 2018 and November 30^th 2019. EGFR p.T790M in plasma samples from mNSCLC patients were tested using dPCR with ADx-ARMS PCR and Cobas^®EGFR Mutation Test V2 as comparator assays to confirm cut-off value for dPCR and evaluate its performance against ARMS-PCR-based assays. Efficacy was evaluated for patients with EGFR p.T790M detected by dPCR or ARMS-PCR, who underwent Osimertinib treatment.

Results

The sensitivity, specificity, and concordance of dPCR against ADx-ARMS PCR was 98.15%, 88.66% and 90.16%, respectively for 1,026 plasma samples. Additional 9.26% patients were detected positive by dPCR. The majority of those samples had a mutation allele frequency between 0.1% and 1%. In 45 paired tissue and plasma samples, the sensitivity improved from 30.77% to 53.85% by dPCR with the specificity over 90%. The response of Osimertinib in 74 EGFR p.T790M-positive patients detected by dPCR, including 26 determined as negative by ARMS-PCR, were evaluated to have an ORR of 44.59% and a DCR of 90.54%.

Conclusions

dPCR is a sensitive and accurate tool for ctDNA-based EGFR p.T790M detection due to its significantly improved sensitivity without compromising specificity, and dPCR is equivalent to ARMS-PCR as a companion diagnostic tool while benefiting more patients under Osimertinib treatment.

Trial Registration

Chinese Clinical Trial Registry identifier: ChiCTR2100043147.

Non-small cell lung cancer cell-derived exosomal miR-17-5p promotes osteoclast differentiation by targeting PTEN

Aberrant activity of bone resorbing osteoclasts plays a key role in the development of osteoporosis and cancer bone metastasis. The identification of novel and specific targets will be helpful for the development of new therapeutic strategies for bone metastasis in lung cancer. Herein, we examined microRNAs in tumor cell-derived exosomes to investigate the communication between the bone environment and tumor cells. TCGA database analysis showed that the level of miR-17-5p increased in non-small cell lung cancer tissues compared with non-tumor tissues. To investigate the function of exosomes in inducing osteoclastogenesis, osteoclast precursors were incubated with exosomes isolated from non-small cell lung cancer cell line, as well as receptor activator of NF-KB ligand and M-CSF to induce osteoclastogenesis. We found that exosomal miR-17-5p is upregulated in a non-small cell lung cancer cell line with bone metastasis compared with the original cell line. Overexpression of miR-17-5p enhanced the osteoclastogenesis of RAW264.7 cells. PTEN was identified as a direct target of miR-17-5p and showed negative effects on osteoclastogenesis. Importantly, treatment of LY294002 (an inhibitor of the PI3K/Akt pathway) attenuated miR-17-5p-mediated osteoclastogenesis effects. Taken together, our findings demonstrated that miR-17-5p promotes osteoclastogenesis through the PI3K/Akt pathway via targeting PTEN in lung cancer.

Performance comparison of commercial kits for isolating and detecting circulating tumor DNA

Circulating tumor DNA (ctDNA), a fraction of cell-free DNA (cfDNA) in the circulatory system, is released from tumor cells and thus carries tumor-specific genetic signatures. Using blood-derived ctDNA to detect somatic mutations has shown great value in guiding cancer targeted therapy. Isolation and detection efficiencies are the key factors affecting the performance of ctDNA detection. To optimize and standardize our clinical practice, in this study, we analyzed the isolation efficiency of four commercial cfDNA purification kits: QIAamp circulating nucleic acid kit, AmoyDx^® Circulating DNA kits, Microdiag^® circulating DNA isolation kit, and MagMAX cell-free DNA isolation kit; and the detection efficiency of two mainstream domestic EGFR gene mutation detection kits: MicroDiag EGFR gene mutation detection kit and Fluorometric real-time PCR Detection Kit for the analysis of EGFR gene mutations. Reference materials and plasma samples collected from lung cancer patients and healthy volunteers were used for the analysis. Our results showed that QIAamp circulating nucleic acid kit and Microdiag^® circulating DNA kit had the highest recovery rate (up to 21.25 ng/mL) for short DNA fragments of about 173 bp which is the peak length of ctDNA. For ctDNA detection, the MicroDiag^® EGFR gene mutation detection kit showed the highest detection rate and sensitivity for detecting EGFR mutations at a mutant frequency of 0.5%. This work provides a reliable choice of commercial kits for the clinical application of ctDNA.

Simplified ARCHITECT microfluidic chip through a dual-flip strategy enables stable and versatile tumoroid formation combined with label-free quantitative proteomic analysis

Recent years, microfluidic three-dimensional(3D) tumor culture technique has made great progress in tumor microenvironment simulation and drug screening. Meanwhile, as their functionality and complexity increase, it is more difficult for current chip models to selectively collect specific-layer cells from tumoroids for further analysis. Moreover, a simplified and robust method for tumoroid formation with highly consistent size and repeatable 3D morphology is relatively ncessary. Here, we report an ARCHITECT (ARtificial CHIp for Tumor Enables Confocal Topography observation) chip, through a dual-flip strategy to implement straightforward tumoroid establishment. This platform guarantees stable batch-to-batch tumoroids formation and allows high resolution confocal imaging. Moreover, an initial cell density as low as 65 cells per chamber is efficient to deliver a tumoroid. With this ARCHITECT chip, different-layer cells of interest could be collected from tumoroid for label-free quantitative(LFQ) proteomic analysis. For application demonstration, we mainly verified this platform for lung carcinoma (A549) tumoroid construction and proteomic analysis at out layer. Our data indicate that the out-layer cells of A549 tumoroid show extensively distinct proteomic expressions compared to two-dimensional cultured A549 cells. The up-regulated proteins are mainly related to tumorigenicity, proliferation and metastasis. And the differentially expressed proteins are mainly relevant to lipid metabolism pathway which is essential to tumor progression and proliferation. This platform provides a simplified yet robust technique to connect microfluidic tumoroid construction and LFQ proteomic analysis. The simplicity of this technique should open the way to numerous applications such as discovering the innovative targets for cancer treatment, and studying the mophological and proteomic heterogeneity of different-layer cells across the tumoroid.

Label-free Separation of Circulating Tumor Cells Using a Self-Amplified Inertial Focusing (SAIF) Microfluidic Chip

Circulating tumor cells (CTCs) are rare cells existing in the bloodstream with a relatively low number, which facilitate as a predictor of cancer progress. However, it is difficult to obtain highly purified intact CTCs with desired viability due to the low percentage of CTCs among blood cells. In this work, we demonstrate a novel self-amplified inertial focused (SAIF) microfluidic chip that enables size-based, high-throughput, label-free separation of CTCs from a patient's blood. The SAIF chip introduced in this study demonstrated the feasibility of an extremely narrow zigzag channel (with 40 μm channel width) connected with two expansion regions to effectively separate different-sized cells with amplified separation distance. The chip performance was optimized with different-sized polystyrene (PS) particles and blood cells spiked with three different types of cancer cells. The separation efficiencies for blood cells and spiked cancer cells are higher than 80%. Recovery rates of cancer cells were tested by spiking 1500 lung cancer cells (A549), breast cancer cells (MCF-7), and cervical cancer cells (HeLa) separately to 3 mL 0.09% saline with 3 × 10⁶ white blood cells (WBCs). The recovery rates for larger cells (MCF-7 and HeLa) were 79.1 and 85.4%, respectively. Viabilities of the cells harvested from outlets were all higher than 97% after culturing for 24, 48, and 72 h. The SAIF chip performance was further confirmed using the real clinical patient blood samples from four lung cancer patients. Theoretical force balance analysis in physics, computational simulations, and experimental observations indicate that the SAIF chip is simple but effective, and high-throughput separation CTCs can be readily achieved without complex structures.

Diagnosis and prognosis for exercise-induced muscle injuries: from conventional imaging to emerging point-of-care testing

With the development of modern society, we have witnessed a significant increase of people who join in sport exercises, which also brings significantly increasing exercise-induced muscle injuries, resulting in reduction and even cessation of participation in sports and physical activities. Although severely injured muscles can hardly realize full functional restoration, skeletal muscles subjected to minor muscle injuries (e.g., tears, lacerations, and contusions) hold remarkable regeneration capacity to be healed without therapeutic interventions. However, delayed diagnosis or inappropriate prognosis will cause exacerbation of the injuries. Therefore, timely diagnosis and prognosis of muscle injuries is important to the recovery of injured muscles. Here, in this review, we discuss the definition and classification of exercise-induced muscle injuries, and then analyze their underlying mechanism. Subsequently, we provide detailed introductions to both conventional and emerging techniques for evaluation of exercise-induced muscle injuries with focus on emerging portable and wearable devices for point-of-care testing (POCT). Finally, we point out existing challenges and prospects in this field. We envision that an integrated system that combines physiological and biochemical analyses is anticipated to be realized in the future for assessing muscle injuries.

Machine learning of serum metabolic patterns encodes early-stage lung adenocarcinoma

Early cancer detection greatly increases the chances for successful treatment, but available diagnostics for some tumours, including lung adenocarcinoma (LA), are limited. An ideal early-stage diagnosis of LA for large-scale clinical use must address quick detection, low invasiveness, and high performance. Here, we conduct machine learning of serum metabolic patterns to detect early-stage LA. We extract direct metabolic patterns by the optimized ferric particle-assisted laser desorption/ionization mass spectrometry within 1 s using only 50 nL of serum. We define a metabolic range of 100–400 Da with 143 m/z features. We diagnose early-stage LA with sensitivity~70–90% and specificity~90–93% through the sparse regression machine learning of patterns. We identify a biomarker panel of seven metabolites and relevant pathways to distinguish early-stage LA from controls (p < 0.05). Our approach advances the design of metabolic analysis for early cancer detection and holds promise as an efficient test for low-cost rollout to clinics.

Early diagnosis significantly improves the probability of successful cancer therapy. Here, the authors develop a technique to analyse serum metabolites and define a biomarker panel for early-stage lung adenocarcinoma diagnosis.

Diagnosis and prognosis of myocardial infarction on a plasmonic chip

Cardiovascular diseases lead to 31.5% of deaths globally, and particularly myocardial infarction (MI) results in 7.4 million deaths per year. Diagnosis of MI and monitoring for prognostic use are critical for clinical management and biomedical research, which require advanced tools with accuracy and speed. Herein, we developed a plasmonic gold nano-island (pGold) chip assay for diagnosis and monitoring of MI. On-chip microarray analysis of serum biomarkers (e.g., cardiac troponin I) afforded up to 130-fold enhancement of near-infrared fluorescence for ultra-sensitive and quantitative detection within controlled periods, using 10 μL of serum only. The pGold chip assay achieved MI diagnostic sensitivity of 100% and specificity of 95.54%, superior to the standard chemiluminescence immunoassay in cardiovascular clinics. Further, we monitored biomarker concentrations regarding percutaneous coronary intervention for prognostic purpose. Our work demonstrated a designed approach using plasmonic materials for enhanced diagnosis and monitoring for prognostic use towards point-of-care testing.

Nanotechnology Strategies for the Analysis of Circulating Tumor DNA: A Review

Circulating tumor DNA (ctDNA) describes the fragmented DNA released from tumor cells into the blood. The ctDNA may have the same genetic changes as the primary tumor. Currently, ctDNA has become a popular biomarker for diagnosis, treatment, real-time clinical response monitoring, and prognosis, for solid tumors. Detection of ctDNA is minimally invasive, and repeat sampling can easily be performed. However, due to its low quality and short DNA fragment length, ctDNA detection still faces challenges and requires highly sensitive analytical techniques. Recently, liquid biopsies for the analysis of circulating tumor cells (CTCs) and circulating tumor-derived exosomes have been studied, and nanotechnology techniques have rapidly developed. Compared to traditional analytical methods, these nanotechnology-based platforms have the advantages of sensitivity, multiplex detection, simplicity, miniaturization, and automation, which support their potential use in clinical practice. This review aims to discuss the recent nanotechnological strategies for ctDNA analysis and the design of reliable techniques for ctDNA detection and to identify the potential clinical applications.

High Expression of Long Noncoding RNA PCNA-AS1 Promotes Non-Small-Cell Lung Cancer Cell Proliferation and Oncogenic Activity via Upregulating CCND1

Accumulating evidences showed that aberrantly expressed long noncoding RNAs (lncRNAs) have critical roles in many cancers. However, the expression and roles of a poorly studied lncRNA PCNA-AS1 in non-small-cell lung cancer (NSCLC) remain unknown. In this study, we investigated the expression, clinical significance, biological roles, and functional mechanism of PCNA-AS1 in NSCLC. Our results showed that PCNA-AS1 was upregulated in NSCLC tissues and cell lines, and correlated with TNM stages. Functional experiments showed that overexpression of PCNA-AS1 promoted NSCLC cell proliferation and cell cycle progression. Depletion of PCNA-AS1 inhibited NSCLC cell proliferation and cell cycle progression, and also inhibited NSCLC tumor growth in vivo. Mechanistically, we found that PCNA-AS1 upregulated CCND1 expression. The expression of PCNA-AS1 was positively correlated with that of CCND1 in NSCLC tissues. Moreover, depletion of CCND1 abrogated the oncogenic roles of PCNA-AS1 in NSCLC. In conclusion, highly expressed PCNA-AS1 promotes NSCLC cell proliferation and oncogenic activity via upregulating CCND1. Our results imply that PCNA-AS1 might serve as a therapeutic target for NSCLC.

Detection of Plasma EGFR Mutations in NSCLC Patients with a Validated ddPCR Lung cfDNA Assay

Purpose: The clinical utility of cell-free DNA (cfDNA) to assess EGFR mutations is increasing. However, there are limited studies determining their clinical validity and utility. The value of cfDNA assays in cancer management remains controversial. Methods: In this study, we first evaluated the analytical performance of the ddPCR Lung cfDNA Assay. We next analyzed the concordance of the results with tissue amplification refractory mutation system PCR (ARMS-PCR) and plasma next-generation sequencing (NGS) genotyping. Finally, we assessed its clinical utility by exploring the association of cfDNA EGFR mutations with metastatic sites and the efficacy of EGFR-TKIs treatment. Results: The ddPCR Lung cfDNA Assay demonstrated a limit of blank of 1 droplet per reaction, an analytical specificity of 100%, and detection limit of 0.05%, 0.05%, and 0.1% for E746_A750del, L858R, and T790M, respectively. With tissue ARMS-PCR as a standard for comparison, the clinical sensitivity and specificity of ddPCR were 62.5% (15/24) and 100% (82/82) for E746_A750del, and 75.0% (15/20) and 94.2% (81/86) for L858R, respectively. The ddPCR showed high concordance with NGS in determining cfDNA EGFR mutations. Patients with bone and/or brain metastasis showed a higher detection rate and mutant abundance of cfDNA EGFR mutations compared to those with other sites of metastasis. Moreover, EGFR-TKIs treatment was effective in patients with sensitive EGFR mutations in either plasma cfDNA or tumor tissue-derived DNA. Conclusions: We validated in this study that the ddPCR Lung cfDNA Assay is reliable for detection of EGFR mutations in lung cancers, in terms of analytical performance, clinical validity and utility.

Multiplexed Detection of Mutant Circulating Tumor DNA Using Peptide Nucleic Acid Clamping Asymmetric Polymerase Chain Reaction and Liquidchip

Circulating tumor DNA (ctDNA) in blood has been investigated as a feasible substitute for genetic alterations in tumor tissues to predict and assess drug responses, but current techniques of screening clinical relevant mutations still have great limitations in sensitivity, specificity, or multiplexed detection because of highly fragmented ctDNA and its low concentration in a high background of normal DNA. In this study, we developed PNA-aPCR-Liquidchip (PAPL), a novel method that aims to detect multiple mutant ctDNA. In order to demonstrate its utility, we analyzed three high frequent epidermal growth factor receptor (EGFR) mutations (exon 19 deletion, L858R, and T790M) in non-small cell lung cancer (NSCLC). Multiplexed analyses indicated that this method has high specificity and sensitivity which could detect down to 2∼5 copies of mutant EGFR in a background of 10,000 copies of wild-type genomic DNA, achieving the mutant abundance of 0.02%∼0.05%. Furthermore, PAPL had no significant differences with droplet digital PCR (ddPCR) in plasma cell-free DNA (cfDNA) detection. Thus, PAPL can be used to detect EGFR mutations in NSCLC patients' plasma, indicating that this method has great potential for application in the context of precision medicine based on mutant ctDNA detection.

Value of folate receptor-positive circulating tumour cells in the clinical management of indeterminate lung nodules: A non-invasive biomarker for predicting malignancy and tumour invasiveness

Background

Non-invasive lung adenocarcinoma could benefit from limited resection, nonetheless, there is a lack of method to determine preoperative tumour invasiveness. We aimed to investigate whether folate receptor-positive circulating tumour cells (FR⁺-CTCs) in combination with maximum tumour diameter (MTD) determines, before surgery, the invasiveness of small-sized, indeterminate solitary pulmonary nodules (SPNs).

Methods

A total of 382 patients with suspicious lung adenocarcinoma on computed tomography who were expected to undergo lung resection were enrolled in this study at three participating institutes and randomly assigned into training and validation cohorts. Before surgery, 3 mL peripheral blood was collected from all participants. FR⁺-CTCs were analyzed using immunomagnetic leukocyte depletion and quantitated by ligand-targeted PCR method. After surgery, the resected tissues were diagnosed by pathologists according to IASLC/ATS/ERS classification.

Findings

FR⁺-CTC levels in the peripheral blood can differentiate benign from malignant nodules with a sensitivity of 78·6%–82·7% and a specificity of 68·8%–78·4%. Both FR⁺-CTC and MTD are independent predictive indices of invasive tumours for lung adenocarcinoma ≤2 cm based on multivariate analyses. Further, FR⁺-CTC count in combination with MTD can differentiate non-invasive cancers from invasive cancers with a sensitivity of 63·6%–81·8% and a specificity of 71·4%–89·7%.

Interpretation

Detection of FR⁺-CTC is a reliable method to differentiate malignancy of indeterminate SPNs. Combining of FR⁺-CTC count and MTD could possibly enhance preoperative determination of the invasiveness of lung nodules and guide surgeons to select limited lung resection and avoid overtreatment for patients with non-invasive lesions.

Fund

None.

Abstract 938: Detection of actionable mutations in plasma cfDNA samples from patients with non-small cell lung carcinoma using a novel amplicon-based Firefly NGS assay

Background: Detection of EGFR, KRAS and BRAF mutations can help guide cancer treatment for non-small cell lung cancer (NSCLC) patients. To identify an easy to use, accurate, multiplex molecular diagnostic assay, we evaluated the performance of a novel next-generation sequencing (NGS)-based cell-free DNA (cfDNA) assay, Firefly assay, which employs a concatemer-based noise suppression mechanism with an amplicon workflow.

Methods: Performance of amplicon based Firefly assay, with a panel covering EGFR, BRAF, and KRAS mutations designed for targeted therapy selection of NSCLC was first evaluated using a cfDNA reference standard and blank control samples. This panel was then used to analyze plasma cfDNA samples from 134 NSCLC cancer patients and 50 non-cancerous controls, and results were compared with tumor tissue ARMS and cfDNA ddPCR results.

Results: Firefly assay demonstrated superior sensitivity and specificity with median detection of 100% at allele frequency of 0.1% for 20ng of cfDNA and zero false positive in all blank control samples. In cfDNA from plasma collected before treatment, EGFR mutation detection by Firefly assay was 94% concordant with tumor tissue ARMS. Firefly assay demonstrated strong per-variant detection-rate concordance (98%) and allele frequency concordance (R2 = 0.95) when compared with cfDNA ddPCR result.

Conclusions: The amplicon based Firefly assay offers multiplex capacity, de novo variant detection, high sensitivity and specificity. Thus, Firefly assay is a kitable NGS solution for cfDNA analysis, which can help guide targeted therapy selection, drug resistance detection, and disease monitoring in NSCLC and other cancer patients.

Citation Format: Lin Wang, Li Weng, Xiao Chen, Min Li, Qiaomei Guo, Wenjun Yu, Tobias Wittkop, Hongyan Wang, Malek Fahem, Shengrong Lin, Grace Q. Zhao, Jiatao Lou. Detection of actionable mutations in plasma cfDNA samples from patients with non-small cell lung carcinoma using a novel amplicon-based Firefly NGS assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 938.

Quality Control of Next-generation Sequencing-based In vitro Diagnostic Test for Onco-relevant Mutations Using Multiplex Reference Materials in Plasma

Background: Widespread clinical implementation of next-generation sequencing (NGS)-based cancer in vitro diagnostic tests (IVDs) highlighted the urgency to establish reference materials which could provide full control of the process from nucleic acid extraction to test report generation. The formalin-fixed, paraffin-embedded (FFPE) tissue and blood plasma containing circulating tumor deoxyribonucleic acid (ctDNA) were mostly used for clinically detecting onco-relevant mutations.

Methods: We respectively developed multiplex FFPE and plasma reference materials covering three clinically onco-relevant mutations within the epidermal growth factor receptor (EGFR) gene at serial allelic frequencies. All reference materials were quantified and validated via droplet digital polymerase chain reaction (ddPCR), and then were distributed to eight domestic manufacturers for the collaborative evaluation of the performance of several domestic NGS-based cancer IVDs covering four major NGS platforms (NextSeq, HiSeq, Ion Proton and BGISEQ).

Results: All expected mutations except one at extremely low allelic frequencies were detected, despite some differences in coefficient of variation (CV) which increased with the decrease of allelic frequency (CVs ranging from 18% to 106%). It was worth noting that the CV value seemed to correlate with a particular mutation as well. The repeatability of determination of different mutations was L858R>T790M>19del.

Conclusions: The results indicated our reference materials would be pivotal for quality control of NGS-based cancer IVDs and would guide the further development of reference materials covering more onco-relevant mutations.

Metabolic Fingerprinting on a Plasmonic Gold Chip for Mass Spectrometry Based in Vitro Diagnostics

Current metabolic analysis is far from ideal to engage clinics and needs rationally designed materials and device. Here we developed a novel plasmonic chip for clinical metabolic fingerprinting. We first constructed a series of chips with gold nanoshells on the surface through controlled particle synthesis, dip-coating, and gold sputtering for mass production. We integrated the optimized chip with microarrays for laboratory automation and micro-/nanoscaled experiments, which afforded direct high-performance metabolic fingerprinting by laser desorption/ionization mass spectrometry using 500 nL of various biofluids and exosomes. Further we for the first time demonstrated on-chip in vitro metabolic diagnosis of early stage lung cancer patients using serum and exosomes. This work initiates a new bionanotechnology based platform for advanced metabolic analysis toward large-scale diagnostic use.

Abstract B071: Detecting ultra low-frequency variants and fusions using a novel amplicon-based Accu-CometTM method

We report the development of an ultra-accurate NGS technology, Accu-CometTM, which employs a concatemer-based error correction with amplicon workflow for the fast detection of low-frequency mutations including single-nucleotide variants (SNVs) and fusion events. We tested a non-small cell lung cancer (NSCLC) panel covering variants of EGFR, BRAF, and KRAS, as well as Alk fusion. Simulated cfDNA and cfDNA from healthy individuals were used to test the assay’s sensitivity and specificity. The analytic sensitivity of this panel was 100% detection at an allele frequency of 0.1% for 20ng of cf-DNA input. Similarly, the analytic sensitivity of the Alk fusion panel was 75% detection at an allele frequency of 0.1%, and 100% detection at an allele frequency of 0.25% for the same input. Clinical validation was performed via a comparative analysis of 171 NSCLC patients at different cancer stages and with different treatment plans. Among our patient cohort, 5 EGFR variants (19del, T790M, L858R, G719X, L861X) were detected. We also tested 47 noncancerous control samples and detected no false-positive variants at the reported cancer hot spots. Accu-CometTM demonstrated strong per-variant detection-rate concordance (&gt; 96%) compared to ddPCR results, and &gt;90% concordance when compared to tumor tissue ARMS result. The multiplex capacity, ultra sensitivity, and easy robust work flow of Accu-CometTM makes it well suited for supporting targeted therapy selection, drug resistance detection, and treatment monitoring.

Citation Format: Ling Wang, Grace Q. Zhao, Li Weng, Xiao Chen, Min Li, Xue Yang, Jun Zhao, Hongyan Wang, Kang Ying, Malek Faham, Shengrong Lin, Jiatao Lou. Detecting ultra low-frequency variants and fusions using a novel amplicon-based Accu-CometTM method [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B071.

Quantification of plasma EGFR mutations in patients with lung cancers: Comparison of the performance of ARMS-Plus and droplet digital PCR

OBJECTIVES

EGFR mutation is a key factor to predict EGFR-TKI efficacy. However, a significant number of advanced patients do not have sufficient tumor specimens for molecular testing. Also, there is a lack of quantitative assay to analyze the mutant abundance. This study aims to evaluate the detection efficiency and clinical feasibility of a new platform, namely ARMS-Plus, for the detection and quantification of EGFR mutations in plasma.

MATERIALS AND METHODS

The detection limit of ARMS-Plus was assessed by detecting spiked mutant plasmids which were serially diluted with normal human genomic DNA. The cutoff values were defined by examining the mutant copy numbers presented in 134 healthy controls. Plasma samples from 65 lung cancer patients were collected to evaluate the clinical performance of ARMS-Plus. EGFR mutations were concurrently tested by droplet digital PCR (ddPCR) for the plasma samples and conventional amplification refractory mutation system-PCR (ARMS-PCR) for the matched tumor tissue specimens to serve as a standard for comparison.

RESULTS

In this study, the analytical sensitivity of ARMS-Plus was 0.015%. The cutoff values of EGFR 19Del, L858R, T790M mutations were defined as 2, 5, and 3 copies/mL, respectively. With tumor specimens as the standard, the sensitivity, specificity, and concordance rate of ARMS-Plus and ddPCR were 60.7%, 94.6%, and 80.0%; and 50.0%, 97.3%, and 76.9%, respectively. For quantification, the plasma 19Del and L858R mutant abundance detected by ARMS-Plus and ddPCR were consistent (Spearman R=0.7956 and 0.7710, P<0.0001).

CONCLUSION

ARMS-Plus is a reliable, convenient and cost-effective method for the detection and quantification of plasma EGFR mutations.

A novel PHD-finger protein 14/KIF4A complex overexpressed in lung cancer is involved in cell mitosis regulation and tumorigenesis

The plant homeodomain (PHD) finger-containing proteins have been implicated in many human diseases including cancer. In this study, we found that PHF14, a newly identified PHD finger protein, is highly expressed in lung cancer. The high expression level of PHF14 was associated with adenocarcinoma and poor survival in lung cancer patients. Knocking down PHF14 suppressed cancer cell growth and carcinogenesis, while over-expressing PHF14 promoted cell proliferation. During cell division, PHF14 directly bound to and co-localized with KIF4A (a nuclear motor protein involved in lung carcinogenesis) to form a functional complex. Similarly to the effect of KIF4A depletion, silencing PHF14 in several cell lines caused cell mitotic defects, prolonged M phase, and inhibited cell proliferation. What's more, these two proteins had a synergistic effect on cell proliferation and were significantly co-overexpressed in lung cancer tissues. Our data provide new insights into the biological significance of PHD finger proteins and imply that PHF14 may be a potential biomarker for lung cancer.

DNA Methylation Analysis of the SHOX2 and RASSF1A Panel in Bronchoalveolar Lavage Fluid for Lung Cancer Diagnosis

Introduction: Currently the majority of lung cancer patients are diagnosed as advanced diseases for no sensitive and specific biomarkers exist, noninvasive biomarkers with high sensitivity and specificity are urgently needed in lung cancer diagnosis. Bronchoscopy is a standard procedure of the diagnostic work-up of patients with suspected lung cancer despite of the limited diagnostic accuracy. Besides, epigenetic changes through DNA methylation play an important role in tumorigenesis. Thus, we examined the aberrant methylation of the SHOX2 and RASSF1A in bronchoalveolar lavage fluid (BALF) in comparing with conventional cytology examination and serum CEA in order to evaluate the new diagnostic method.

Patients and Methods: BALF and serum samples were collected from 322 patients at the time of diagnosis, 284 of them were pathologically confirmed lung cancer, 35 were benign lung diseases and 3 were malignancies in other systems. For all of the 322 patients, the methylation status of the SHOX2 and RASSF1A gene were detected by a new RT-PCR platform and then confirmed by sanger sequencing. Serum CEA were detected using electrochemiluminescence immunoassay.

Results: Profiling data showed the consistency of RT-PCR and sanger sequencing in detecting the methylation of the SHOX2 and RASSF1A. Besides, the combination of SHOX2 and RASSF1A methylation in BALF yielded a diagnostic sensitivity of 81.0% and specificity of 97.4%. When compared with established cytology examination (sensitivity: 68.3%, specificity: 97.4%) and serum biomarker carcinoembryonic antigen (CEA) (sensitivity: 30.6%, specificity: 100.0%), the SHOX2 and RASSF1A methylation panel showed the highest diagnostic efficiency. Notably, the combination of cytology and the SHOX2 and RASSF1A methylation panel could significantly improve the diagnostic efficacy.

Conclusion: The methylation analysis of the SHOX2 and RASSF1A panel in BALF with RT-PCR achieved a satisfactory sensitivity and specificity in lung cancer diagnosis, especially in an early stage. It could be used as a promising noninvasive biomarker for auxiliary diagnosis of lung cancer.

Detecting ultra low-frequency variants and gene fusions in lung cancer patients using an amplicon-based Firefly NGS method

e23062

Background: The analysis of EGFR, KRAS, and BRAF mutations and Alk fusion is critical for guiding targeted therapy selection, detecting drug resistance, and monitoring residual disease in patients with NSCLC. Designing next-generation sequencing (NGS) assays for detecting low-frequency variants, however, is an ongoing challenge. The limited availability of cfDNA combined with the breadth of coverage necessary to create meaningful, clinically-actionable results requires a solution with multiplex capacity which, in turn, requires greater technological sensitivity and specificity. Here we aim to develop such a solution: an ultra-accurate NGS technology using concatmer-based error correction with amplicon workflow for fast detection of rare mutations including SNV and fusion. Methods: We developed an amplicon-based panel covering variants of EGFR, BRAF, and KRAS, as well as a panel to detect Alk fusion. CfDNA simulate and cfDNA from healthy individuals were used to test assay sensitivity and specificity. Further validation was performed via a comparative analysis of 64 late-stage lung cancer patients using both Firefly -Comet and ddPCR. Results: Analytical sensitivity of the EGFR-TKI 3-gene panel was 100% detection at an allele frequency of 0.1% for 20ng of cfDNA input. Similarly, analytical sensitivity of the Alk fusion panel was 75% detection at an allele frequency of 0.1% and 100% at an allele frequency of 0.25% for the same input. Among our patient cohort, 5 EGFR variants (19del, T790M, L858R, G719X, L861X) and 2 KRAS variant (G12X) were detected. Firefly-Comet demonstrated strong per-variant detection-rate concordance ( > 99%) compared to ddPCR results. The PPV is 100% and the NPV is 98.7%. Statistical analysis of reported allele frequency concordance between Firefly-Comet and ddPCR reveals R-Sq > 0.9. Conclusions: In summary, we have developed Firefly-Comet, an easy-to-use amplicon-based NGS assay capable of detecting single-digit copies of somatic mutants and gene fusions in cfDNA. The multiplex capacity of Firefly-Comet makes it well-suited for supporting targeted therapy selection, drug resistance detection, and treatment monitoring.

IQGAP1 Mediates Hcp1-Promoted Escherichia coli Meningitis by Stimulating the MAPK Pathway

Escherichia coli-induced meningitis remains a life-threatening disease despite recent advances in the field of antibiotics-based therapeutics, necessitating continued research on its pathogenesis. The current study aims to elucidate the mechanism through which hemolysin-coregulated protein 1 (Hcp1) induces the apoptosis of human brain microvascular endothelial cells (HBMEC). Co-immunoprecipitation coupled with mass spectrometric (MS) characterization led to the identification of IQ motif containing GTPase activating protein 1 (IQGAP1) as a downstream target of Hcp1. IQGAP1 was found to be up-regulated by Hcp1 treatment and mediate the stimulation of HBMEC apoptosis. It was shown that Hcp1 could compete against Smurf1 for binding to IQGAP1, thereby rescuing the latter from ubiquitin-dependent degradation. Subsequent study suggested that IQGAP1 could stimulate the MAPK signaling pathway by promoting the phosphorylation of ERK1/2, an effect that was blocked by U0126, an MAPK inhibitor. Furthermore, U0126 also demonstrated therapeutic potential against E. coli meningitis in a mouse model. Taken together, our results suggested the feasibility of targeting the MAPK pathway as a putative therapeutic strategy against bacterial meningitis.

Biomarkers for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. The HCC diagnosis is usually achieved by biomarkers, which can also help in prognosis prediction. Furthermore, it might represent certain therapeutic interventions through some combinations of biomarkers. Here, we review on our current understanding of HCC biomarkers.

Identification of A Panel of Serum microRNAs as Biomarkers for Early Detection of Lung Adenocarcinoma

Introduction: Since currently no sensitive and specific biomarkers for early detection of lung adenocarcinoma (AD) exist and the majority of AD patients are diagnosed at late stages of disease, the development of effective screening tests for early-stage lung AD is urgently needed. Serum microRNAs (miRNAs) have been documented as novel noninvasive biomarkers in tumor diagnosis; thus, we studied the profile of serum miRNA in AD patients in order to identify the differentially expressed miRNAs as potential biomarkers for early detection of AD.

Patients and Methods: Serum samples were collected from 180 AD patients and 180 age- and sex-matched healthy controls. Serum miRNA profiling was performed by low-density array (LDA) using RNA extracted from blood samples of 20 patients and 20 controls. To validate the selected miRNAs, a stem-loop based RT-qPCR assay was used and serum samples from 160 patients and 160 controls were examined.

Results: Profiling data showed 11 differentially expressed miRNAs in the serum samples from AD patients compared with the controls. Among them, 6 selected miRNAs in AD patients, including miR-103, miR-146a, miR-151, miR-21, miR-221, miR-222, and miR-223, were validated by RT-qPCR. In particular, the top three, miR-146a, miR-222, and miR-223, were confirmed to be significantly expressed in stage I/II AD patients compared with healthy controls.

Conclusion: A panel of miRNAs with miR-146a, miR-222 and miR-223 could be used as potential noninvasive biomarkers for early detection of AD.

Clinical Significance of Folate Receptor-positive Circulating Tumor Cells Detected by Ligand-targeted Polymerase Chain Reaction in Lung Cancer

Background: As the heterogeneity of CTCs is becoming increasingly better understood, it is clear that identifying particular subtypes of CTCs would be more relevant.

Methods: We detected folate receptor (FR)-positive circulating tumor cells (FR⁺-CTCs) by a novel ligand-targeted polymerase chain reaction (LT-PCR) detection technique.

Results: In the none-dynamic study, FR⁺-CTC levels of patients with lung cancer were significantly higher than controls (patients with benign lung diseases and healthy controls). With a threshold of 8.7 CTC units, FR⁺-CTC showed a sensitivity of 77.7% and specificity of 89.5% in the diagnosis of lung cancer. When compared with established clinical biomarkers including carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA21-1), and neuron-specific enolase (NSE), FR⁺-CTC showed the highest diagnostic efficiency. Notably, the combination of FR⁺-CTC, CEA, NSE, and CYFRA21-1 could significantly improve the diagnostic efficacy in differentiating patients with lung cancer from benign lung disease. In our dynamic surveillance study, the CTC levels of 62 non-small cell lung cancer (NSCLC) patients decreased significantly after tumor resection.

Conclusion: We established a LT-PCR-based FR⁺-CTC detection platform for patients with lung cancer that exhibits high sensitivity and specificity. This platform would be clinical useful in lung cancer diagnosis and treatment response assessment.

Abstract 2247: A multicenter clinical trial of lung cancer circulating tumor cell assay with the largest sample size (1210 cases) in China

Background: As a novel biomarker of primary tumors, circulating tumor cells (CTCs) are well known to play an important role in cancer diagnosis, recurrence and metastasis, and disease monitoring. This study investigated the application of CTCs in lung cancer therapy by quantitative determination of folate receptor-positive CTCs.

Methods: This study enrolled 1210 subjects (including 560 lung cancer patients, 350 patients with benign lung diseases, 150 healthy subjects and 150 non-lung cancer malignant tumor patients) and quantified the tiny amounts of CTCs in peripheral blood by negative enrichment using immunomagnetic beads in combination with folate receptor-directed polymerase chain reaction (PCR).

Results: Following ROC curve analyses of CTC levels in the patients with benign lung diseases or benign lung diseases and the healthy subjects, the cut-off of CTCs was 8.70 CTC Units/3mL with a specificity of 88.2% (441/500) and a sensitivity of 79.6% (446/560) as determined by the method mentioned above. The ROC area under

curve of more than 0.8 (AUC = 0.8797, P&lt;0.0001) suggested the excellence of ligand-directed PCR to diagnose lung cancer. For stage II-IV lung cancer patients, the sensitivities were 70.8%(34/48), 79.6% (125/157), and 90.2% (185/205) respectively, and the sensitivity in stage I patients can reach up to 68.0% (102/150) as well. CTC levels appeared to have greater accuracy to diagnose lung cancer (AUC: 0.8833, P&lt;0.0001) than the combination of the other four lung cancer-specific serum tumor markers (CEA, NSE, CYFRA21-1 and SCC)(AUC: 0.8557, P&lt;0.0001). CTCs were related to tumor stage and tumor size other than pathological type. By quantitative determination of folate receptor-positive cells in 150 different types of cancers, the CTC level in lung cancer was found to be higher than those in gastric, breast, colorectal, liver, and esophageal cancers.

Conclusions: LT-PCR achieves quantitative determination of folate receptor-positive CTCs to diagnose lung cancer with high sensitivity and specificity, and significantly greater diagnosis accuracy than the model of combined lung cancer-specific serum tumor markers.

Citation Format: Jiatao Lou, Caicun Zhou, Jing Wu, Lihua Qiao, Xiaohui Liang, Xiaoqian Wang, Xiaoxia Chen, Xuefei Li, Chao Zhao. A multicenter clinical trial of lung cancer circulating tumor cell assay with the largest sample size (1210 cases) in China. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2247.

Multifunctional Magnetic Particles for Combined Circulating Tumor Cells Isolation and Cellular Metabolism Detection

We for the first time demonstrate multi-functional magnetic particles based rare cell isolation combined with the downstream laser desorption/ionization mass spectrometry (LDI-MS) to measure the metabolism of enriched circulating tumor cells (CTCs). The characterization of CTCs metabolism plays a significant role in understanding the tumor microenvironment, through exploring the diverse cellular process. However, characterizing cell metabolism is still challenging due to the low detection sensitivity, high sample complexity, and tedious preparation procedures, particularly for rare cells analysis in clinical study. Here we conjugate ferric oxide magnetic particles with anti-EpCAM on the surface for specific, efficient enrichment of CTCs from PBS and whole blood with cells concentration of 6-100 cells per mL. Moreover, these hydrophilic particles as matrix enable sensitive and selective LDI-MS detection of small metabolites (MW<500 Da) in complex bio-mixtures and can be further coupled with isotopic quantification to monitor selected molecules metabolism of ~50 CTCs. Our unique approach couples the immunomagnetic separation of CTCs and LDI-MS based metabolic analysis, which represents a key step forward for downstream metabolites analysis of rare cells to investigate the biological features of CTCs and their cellular responses in both pathological and physiological phenomena.

Identification and distinction of non-small-cell lung cancer cells by intracellular SERS nanoprobes

Combination of surface enhanced Raman scattering and multivariate statistical method allows to identify and distinguish three subtypes of non-small-cell lung cancer cells and leukocytes on the single-cell level.

MiR-181a-5p inhibits cell proliferation and migration by targeting Kras in non-small cell lung cancer A549 cells

MicroRNAs play important roles in carcinogenesis and tumor progress. Lung cancer is the leading cause of cancer mortality worldwide. In this study, the function of miR-181a-5p was investigated in non-small-cell lung cancer (NSCLC). Results showed that miR-181a-5p was significantly decreased in NSCLC tissues and cell lines. The proliferation and migration of A549 cells transfected with miR-181a-5p mimic was significantly inhibited. Luciferase activity assay results demonstrated that two binding sites of Kras could be directly targeted by miR-181a-5p. Furthermore, Kras was down-regulated by miR-181a-5p at both transcriptional and translational levels. SiRNA-mediated Kras down-regulation could mimic the effects of miR-181a-5p mimic in A549 cells. Our findings suggest that miR-181a-5p plays a potential role in tumor suppression by partially targeting Kras and has the potential therapeutic application in NSCLC patients.

Plasma levels of heat shock protein 90 alpha associated with lung cancer development and treatment responses

PURPOSE

Altered expression of heat shock protein 90 alpha (Hsp90α) was associated with tumor development, progression, and metastasis. This study explored plasma levels of Hsp90α protein in patients with lung cancer and other controls to assess its diagnostic value and monitor treatment responses for patients with lung cancer.

EXPERIMENTAL DESIGN

A total of 2,247 individuals were recruited and assigned into two cohorts as static and dynamic groups. ELISA analysis and confirmation of plasma Hsp90α protein levels for association with tumor stages and treatment responses, respectively, were performed.

RESULTS

The average plasma levels of Hsp90α protein in patients with lung cancer were significantly higher than in healthy controls (P < 0.0001). Plasma levels of Hsp90α protein in patients with advanced lung cancer (stage III-IV) were higher than in patients with early-stage lung cancer (stage I-II; P < 0.001). Using a cutoff value of 56.33 ng/mL to separate lung cancer from other controls, the sensitivity and specificity reached 72.18% (95% CI, 0.695-0.749) and 78.70% (95% CI, 0.761-0.813), respectively. To confirm the different levels in the second cohort, plasma levels of Hsp90α protein showed a statistically significant difference between preoperative and postoperative patients in surgical patient groups (P < 0.007). There was also a statistically significant difference between the disease progressive group and stable disease group, with regard to partial response after chemotherapy (P < 0.0001).

CONCLUSIONS

This study demonstrated that plasma Hsp90α protein levels are useful as a diagnostic biomarker in lung cancer and predict the responses of patients with lung cancer to chemotherapy.

Quantification of rare circulating tumor cells in non-small cell lung cancer by ligand-targeted PCR

Background

Quantification of circulating tumor cells (CTC) is valuable for evaluation of non-small cell lung cancer (NSCLC). The sensitivity of current methods constrains their use to detect rare CTCs in early stage. Here we evaluate a novel method, ligand-targeted polymerase chain reaction (LT-PCR), that can detect rare CTCs in NSCLC patients.

Methods

CTCs were enriched by immunomagnetic depletion of leukocytes and then labeled by a conjugate of a tumor-specific ligand and an oligonucleotide. After washing off free conjugates, the bound conjugates were stripped from CTCs and then analyzed by qPCR. To evaluate the clinical utility, blood samples were obtained from 72 NSCLC patients (33 initially diagnosed and 39 on chemotherapy), 20 benign patients, and 24 healthy donors.

Results

Experiments with healthy blood spiked with tumor cells indicated the LT-PCR allows specific detection of CTC. The clinical study showed that the initially diagnosed patients have an average of 20.8 CTC units with metastatic diseases, 11.8 CTC units with localized diseases, and 6.0 CTC units with benign diseases. With the threshold of 8.5 CTC units, the assay can detect 80% of stage I/II, 67% of stage III, and 93% of stage IV cancer. With the benign patients and healthy donors as control group, the method can detect cancer with a sensitivity of 81.8% and a specificity of 93.2%.

Conclusion

The LT-PCR would allow quantification of CTC in NSCLC patients at a more sensitive level, providing a potential tool for stratifying malignant lung diseases, especially at early stage.

Transcriptome-wide network analysis of squamous lung cancer reveals potential methylation genes

Lung cancer is a prevalent cancer with a high death rate. Underlying mechanisms have been found to be highly correlated with epigenetics, especially with DNA methylation. With methylation array and other regulation data, we constructed a TF-gene regulation network and a TF-pathway network. Through those networks, we identified lung cancer related genes that were found by previous studies, and supposed a number of new examples. Our work demonstrated the new potential methylation for lung cancer.

[Diagnostic value of bone metabolic markers ICTP and BAP in lung cancer patients with bone metastases]

背景与目的

骨代谢标志物是一类源于骨基质或骨细胞的代谢指标，可反映骨代谢情况。本研究旨在探讨血清骨代谢生化指标Ⅰ型胶原交联羧基端肽（cross-linked telopeptide of type Ⅰ collage, ICTP）和骨特异性碱性磷酸酶（bone-specific alkaline phosphatase, BAP）在肺癌骨转移诊断中的意义及其临床应用价值。

方法

采用前瞻性对照方法，共入组110例，分为3组。初治肺癌患者共90例，临床分期为Ⅳ期，分为骨转移组50例和非骨转移组40例，健康对照组20例，采用酶联免疫法和电化学发光免疫测定法检测所有入组者治疗前的血清骨代谢生化指标ICTP和BAP水平，对骨转移的各因素与血清ICTP和BAP的相关性进行统计学分析。

结果

骨转移组的血清ICTP和BAP水平显著高于非骨转移组和健康对照组（P < 0.05）。多发性骨转移组（骨转移数≥3）的血清BAP水平显著高于少发性骨转移组（骨转移数 < 3）（P < 0.05）。混合性骨转移组的血清BAP水平显著高于溶骨性骨转移组（P < 0.05）。ICTP和BAP在肺癌骨转移诊断中的敏感性分别为18%和40%，特异性分别为98.3%和95%，准确度分别为61.8%和70%。联合检测血清ICTP和BAP可提高其敏感性和准确度（分别为52%和74.5%）。

结论

由于检测方便、无创性、成本较低，血清骨代谢生化指标ICTP和BAP在肺癌骨转移的临床诊断中有一定的实用价值。