Analytical and Clinical Validation of a Target-Enhanced Whole Genome Sequencing-Based Comprehensive Genomic Profiling Test.

Evaluation of the test performance of the Target enhanced whole-genome sequencing (TE-WGS) assay for comprehensive oncology genomic profiling. The analytical validation of the assay included sensitivity and specificity for single nucleotide variants (SNVs), insertions/deletions (indels), and structural variants (SVs), revealing a revealed a sensitivity of 99.8% for SNVs and 99.2% for indels. The positive predictive value (PPV) was 99.3% SNVs and 98.7% indels. Clinical validation was benchmarked against established orthogonal methods and demonstrated high concordance with reference methods. TE-WGS provides insights beyond targeted panels by comprehensive analysis of key biomarkers and the entire genome encompassing both germline and somatic findings.

Quantitative and qualitative mutational impact of ionizing radiation on normal cells.

The comprehensive genomic impact of ionizing radiation (IR), a carcinogen, on healthy somatic cells remains unclear. Using large-scale whole-genome sequencing (WGS) of clones expanded from irradiated murine and human single cells, we revealed that IR induces a characteristic spectrum of short insertions or deletions (indels) and structural variations (SVs), including balanced inversions, translocations, composite SVs (deletion-insertion, deletion-inversion, and deletion-translocation composites), and complex genomic rearrangements (CGRs), including chromoplexy, chromothripsis, and SV by breakage-fusion-bridge cycles. Our findings suggest that 1 Gy IR exposure causes an average of 2.33 mutational events per Gb genome, comprising 2.15 indels, 0.17 SVs, and 0.01 CGRs, despite a high level of inter-cellular stochasticity. The mutational burden was dependent on total irradiation dose, regardless of dose rate or cell type. The findings were further validated in IR-induced secondary cancers and single cells without clonalization. Overall, our study highlights a comprehensive and clear picture of IR effects on normal mammalian genomes.

Strategies to Improve Smoking Cessation for Participants in Lung Cancer Screening Program: Analysis of Factors Associated with Smoking Cessation in Korean Lung Cancer Screening Project (K-LUCAS).

PURPOSE: Smoking cessation intervention is one of the key components of successful lung cancer screening program. We investigated the effectiveness and related factors of smoking cessation services provided to the participants in a population-based lung cancer screening trial. MATERIALS AND METHODS: The Korean Lung Cancer Screening Project (K-LUCAS) is a nationwide, multi-center lung cancer screening trial that evaluates the feasibility of implementing population-based lung cancer screening. All 5,144 current smokers who participated in the K-LUCAS received a mandatory smoking cessation counseling. Changes in smoking status were followed up using a telephone survey in 6 months after lung cancer screening participation. The lung cancer screening's impact on smoking cessation is analyzed by variations in the smoking cessation interventions provided in screening units. RESULTS: Among 4,136 survey responders, participant's motivation to quit smoking increased by 9.4% on average after lung cancer screening. After 6 months from the initial screening, 24.3% of participants stopped smoking, and 10.6% of participants had not smoked continuously for at least 6 months after screening. Over 80% of quitters stated that participation in lung cancer screening motivated them to quit smoking. Low-cost public smoking cessation program combined with lung cancer screening increased the abstinence rates. The smokers were three times more likely to quit smoking when the smoking cessation counseling was provided simultaneously with low-dose computed tomography screening results than when provided separately. CONCLUSION: A mandatory smoking cessation intervention integrated with screening result counselling by a physician after participation in lung cancer screening could be effective for increasing smoking cessation attempts.

Longitudinal multi-omics study of palbociclib resistance in HR-positive/HER2-negative metastatic breast cancer.

BACKGROUND: Cyclin-dependent kinase 4/6 inhibitor (CDK4/6) therapy plus endocrine therapy (ET) is an effective treatment for patients with hormone receptor-positive/human epidermal receptor 2-negative metastatic breast cancer (HR+/HER2- MBC); however, resistance is common and poorly understood. A comprehensive genomic and transcriptomic analysis of pretreatment and post-treatment tumors from patients receiving palbociclib plus ET was performed to delineate molecular mechanisms of drug resistance. METHODS: Tissue was collected from 89 patients with HR+/HER2- MBC, including those with recurrent and/or metastatic disease, receiving palbociclib plus an aromatase inhibitor or fulvestrant at Samsung Medical Center and Seoul National University Hospital from 2017 to 2020. Tumor biopsy and blood samples obtained at pretreatment, on-treatment (6 weeks and/or 12 weeks), and post-progression underwent RNA sequencing and whole-exome sequencing. Cox regression analysis was performed to identify the clinical and genomic variables associated with progression-free survival. RESULTS: Novel markers associated with poor prognosis, including genomic scar features caused by homologous repair deficiency (HRD), estrogen response signatures, and four prognostic clusters with distinct molecular features were identified. Tumors with TP53 mutations co-occurring with a unique HRD-high cluster responded poorly to palbociclib plus ET. Comparisons of paired pre- and post-treatment samples revealed that tumors became enriched in APOBEC mutation signatures, and many switched to aggressive molecular subtypes with estrogen-independent characteristics. We identified frequent genomic alterations upon disease progression in RB1, ESR1, PTEN, and KMT2C. CONCLUSIONS: We identified novel molecular features associated with poor prognosis and molecular mechanisms that could be targeted to overcome resistance to CKD4/6 plus ET. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03401359. The trial was posted on 18 January 2018 and registered prospectively.

Plastic Shavings by Laser: Peeling Porous Graphene Springs for Multifunctional All-Carbon Applications.

Manufacturing strategies to create three-dimensional (3D) structures with multifunctional nanomaterials are of intense interest for fabricating building blocks in many electromechanical applications. A coil spring composed of graphene provides an important step toward the realization of all-carbon devices, as it is one of the essential elements for a wide range of systems. In this connection, here an unprecedented fabrication strategy to create a new type of 3D coil spring composed of laser-induced graphene springs (LIG-S) which is spontaneously produced via the pyrolytic jetting technique, is presented. Similar to wood or metal shavings observed in traditional machining processes, a pair of LIG-S with two opposite chiralities and controllable macroscopic dimensions is produced by a single scanning of a focused continuous-wave (CW) laser on a polyimide (PI) substrate. The resulting LIG-S, plastic shavings by laser, exhibits sufficient mechanical and electrical properties to enable many applications including strain-tolerant spring electrodes, antennas, supercapacitors, gas sensors, and luminescent filaments under extreme conditions. Without using any conventional fabrication techniques or other labor-intensive, time-consuming, and expensive processes, this novel approach enables a high-throughput mass production of macro-, micro-, and nanoscale featured LIG-S that can be manufactured within seconds to realize many open opportunities in all-carbon electromechanical systems.

Direct Observation of Off-Stoichiometry-Induced Phase Transformation of 2D CdSe Quantum Nanosheets.

Crystal structures determine material properties, suggesting that crystal phase transformations have the potential for application in a variety of systems and devices. Phase transitions are more likely to occur in smaller crystals; however, in quantum-sized semiconductor nanocrystals, the microscopic mechanisms by which phase transitions occur are not well understood. Herein, the phase transformation of 2D CdSe quantum nanosheets caused by off-stoichiometry is revealed, and the progress of the transformation is directly observed by in situ transmission electron microscopy. The initial hexagonal wurtzite-CdSe nanosheets with atomically uniform thickness are transformed into cubic zinc blende-CdSe nanosheets. A combined experimental and theoretical study reveals that electron-beam irradiation can change the stoichiometry of the nanosheets, thereby triggering phase transformation. The loss of Se atoms induces the reconstruction of surface atoms, driving the transformation from wurtzite-CdSe(11 2 ¯ $\bar{2}$ 0) to zinc blende-CdSe(001) 2D nanocrystals. Furthermore, during the phase transformation, unconventional dynamic phenomena occur, including domain separation. This study contributes to the fundamental understanding of the phase transformations in 2D quantum-sized semiconductor nanocrystals.

Analysis of genomic and immune intratumor heterogeneity in linitis plastica via multiregional exome and T-cell receptor sequencing.

The molecular landscape and the intratumor heterogeneity (ITH) architecture of gastric linitis plastica (LP) are poorly understood. We performed whole-exome sequencing (WES) and T-cell receptor (TCR) sequencing on 40 tumor regions from four LP patients. The landscape and ITH at the genomic and immunological levels in LP tumors were compared with multiple cancers that have previously been reported. The lymphocyte infiltration was further assessed by immunohistochemistry (IHC) in LP tumors. In total, we identified 6339 non-silent mutations from multi-samples, with a median tumor mutation burden (TMB) of 3.30 mutations per Mb, comparable to gastric adenocarcinoma from the Cancer Genome Atlas (TCGA) cohort (P = 0.53). An extremely high level of genomic ITH was observed, with only 12.42%, 5.37%, 5.35%, and 30.67% of mutations detectable across 10 regions within the same tumors of each patient, respectively. TCR sequencing revealed that TCR clonality was substantially lower in LP than in multi-cancers. IHC using antibodies against CD4, CD8, and PD-L1 demonstrated scant T-cell infiltration in the four LP tumors. Furthermore, profound TCR ITH was observed in all LP tumors, with no T-cell clones shared across tumor regions in any of the patients, while over 94% of T-cell clones were restricted to individual tumor regions. The Morisita overlap index (MOI) ranged from 0.21 to 0.66 among multi-regions within the same tumors, significantly lower than that of lung cancer (P = 0.002). Our results show that LP harbored extremely high genomic and TCR ITH and suppressed T-cell infiltration, suggesting a potential contribution to the frequent recurrence and poor therapeutic response of this adenocarcinoma.

Spin Coating Promotes the Epitaxial Growth of AgCN Microwires on 2D Materials.

Epitaxial growth of inorganic crystals on 2D materials is expected to greatly advance nanodevices and nanocomposites. However, because pristine surfaces of 2D materials are chemically inert, it is difficult to grow inorganic crystals epitaxially on 2D materials. Previously, successful results were achieved only by vapor-phase deposition at high temperature, and solution-based deposition including spin coating made the epitaxial growth unaligned, sparse, or nonuniform on 2D materials. Here, we show that solvent-controlled spin coating can uniformly deposit a dense layer of epitaxial AgCN microwires onto various 2D materials. Adding ethanol to an aqueous AgCN solution facilitates uniform formation of the thin supersaturated solution layer during spin coating, which promotes heterogeneous crystal nucleation on 2D material surfaces over homogeneous nucleation in the bulk solution. Microscopic analysis confirms highly aligned, uniform, and dense growth of epitaxial AgCN microwires on graphene, MoS2, hBN, WS2, and WSe2. The epitaxial microwires, which are optically observable and chemically removable, enable crystallographic mapping of grains in millimeter-sized polycrystalline graphene as well as precise control of twist angles (<∼1°) in van der Waals heterostructures. In addition to these practical applications, our study demonstrates the potential of 2D materials as epitaxial templates even in spin coating of inorganic crystals.

Observation of H2 Evolution and Electrolyte Diffusion on MoS2 Monolayer by In Situ Liquid-Phase Transmission Electron Microscopy.

Unit-cell-thick MoS2 is a promising electrocatalyst for the hydrogen evolution reaction (HER) owing to its tunable catalytic activity, which is determined based on the energetics and molecular interactions of different types of HER active sites. Kinetic responses of MoS2 active sites, including the reaction onset, diffusion of the electrolyte and H2 bubbles, and continuation of these processes, are important factors affecting the catalytic activity of MoS2 . Investigating these factors requires a direct real-time analysis of the HER occurring on spatially independent active sites. Herein, the H2 evolution and electrolyte diffusion on the surface of MoS2 are observed in real time by in situ electrochemical liquid-phase transmission electron microscopy (LPTEM). Time-dependent LPTEM observations reveal that different types of active sites are sequentially activated under the same conditions. Furthermore, the electrolyte flow to these sites is influenced by the reduction potential and site geometry, which affects the bubble detachment and overall HER activity of MoS2 .

Immunogenomic profiling of lung adenocarcinoma reveals poorly differentiated tumors are associated with an immunogenic tumor microenvironment.

OBJECTIVES: Pathologists have routinely observed distinct histologic patterns of growth in early-stage lung adenocarcinoma (LUAD), which have been suggested to be associated with prognosis. Herein, we investigated the relationship between LUAD patterns of growth, as defined by the updated international association for the study of lung cancer (IASLC) grading criteria, and differences in the tumor immune microenvironment to identify predictors of response to immunotherapy. METHODS: 174 resected stage I-III LUAD tumors were classified by histologic pattern of growth (i.e. solid, micropapillary, acinar, papillary, and lepidic) and then grouped as well differentiated, moderately differentiated, and poorly differentiated. Comprehensive multiplatform analysis including whole exome sequencing, gene expression profiling, immunohistochemistry, CIBERSORT, and T-cell receptor sequencing was performed and groups were compared for differences in genomic drivers, immune cell infiltrate, clonality, and survival. Finally, multivariate analysis was performed adjusting for pathologic stage and smoking status. RESULTS: Poorly differentiated tumors demonstrated a strong association with smoking relative to moderately differentiated or well differentiated tumors. However, unlike in prior reports, poorly differentiated tumors were not associated with a worse survival after curative-intent resection. Genomic analysis revealed that poorly differentiated tumors are associated with high tumor mutation burden but showed no association with oncogenic drivers. Immune analyses revealed that poorly differentiated tumors are associated with increased T-cell clonality, expression of PD-L1, and infiltration by cytotoxic CD8 T-cells, activated CD4 T-cells, and pro-inflammatory (M1) macrophages. Finally, multivariate analysis controlling for stage and smoking status confirmed independence of immune differences between IASLC grade groups. CONCLUSIONS: Poorly differentiated tumors, as defined by the updated IASLC grading criteria, are associated with a distinct immunogenic tumor microenvironment that predicts for therapeutic response to immune agents, including checkpoint inhibitors, and should be included in the clinical trial design of immunotherapy studies in early-stage lung adenocarcinoma.

Organometallic hotspot engineering for ultrasensitive EC-SERS detection of pathogenic bacteria-derived DNAs.

The sensitivity and limit-of-detection (LOD) of the traditional surface-enhanced Raman spectroscopy (SERS) platform suffer from the requirement of precise positioning of small analytes, including DNAs and bacteria, into narrow hotspots. In this study, a novel SERS sensor was developed using electrochemical deposition onto metal nanopillars (ECOMPs) combined with complementary DNAs (cDNAs) for the detection of pathogenic bacteria. Applying a redox potential to AuCl4- ions actively engineered the organometallic hotspots based on the cDNAs in a short time (<10 min) and simultaneously produced SERS signals. Because of the influence of potential-driven morphological properties on the SERS efficiency in the cDNA domains and the resonant coupling of internal fields with the fields confined between adjacent ECOMPs-cDNAs, the optimum growth time was determined to be 5 min. The EC-SERS detection and discrimination of Enterococcus faecium and Staphylococcus aureus were successfully carried out because of the DNA complementarity. Compared with plasmonic metal nanopillars (MPs)-cDNAs, the enhancement factor of the ECOMPs-cDNAs was estimated to be ∼2.0 × 103. A quantitative investigation revealed that a highly linear progression in the target DNA concentration range (0.05-100 nM) and a LOD of ∼0.035 nM were achieved. The specificity of the ECOMPs-cDNAs was validated by cross-hybridization. The platform was also used to assay human whole blood containing 0.1 nM bacterial DNAs. The proposed strategy provides the potential for highly sensitive SERS-based multiplex DNA detection in clinical diagnostics.

Response to Comment on "Reversible disorder-order transitions in atomic crystal nucleation".

Yu et al. suggested calculating precisely the size ranges of the three parts of our figure 3A, adjusting the free-energy levels in figure 3B, and considering the shape effect in the first-principles calculation. The first and second suggestions raise strong concerns for misinterpretation and overinterpretation of our experiments. The original calculation is sufficient to support our claim about crystalline-to-disordered transformations.

The histologic phenotype of lung cancers is associated with transcriptomic features rather than genomic characteristics.

Histology plays an essential role in therapeutic decision-making for lung cancer patients. However, the molecular determinants of lung cancer histology are largely unknown. We conduct whole-exome sequencing and microarray profiling on 19 micro-dissected tumor regions of different histologic subtypes from 9 patients with lung cancers of mixed histology. A median of 68.9% of point mutations and 83% of copy number aberrations are shared between different histologic components within the same tumors. Furthermore, different histologic components within the tumors demonstrate similar subclonal architecture. On the other hand, transcriptomic profiling reveals shared pathways between the same histologic subtypes from different patients, which is supported by the analyses of the transcriptomic data from 141 cell lines and 343 lung cancers of different histologic subtypes. These data derived from mixed histologic subtypes in the setting of identical genetic background and exposure history support that the histologic fate of lung cancer cells is associated with transcriptomic features rather than the genomic profiles in most tumors.

Epitaxial Growth of Diamond-Shaped Au1/2Ag1/2CN Nanocrystals on Graphene.

Epitaxial synthesis of inorganic nanomaterials on pristine 2D materials is of interest in the development of nanostructured devices and nanocomposite materials, but is quite difficult because pristine surfaces of 2D materials are chemically inert. Previous studies found a few exceptions including AuCN, AgCN, CuCN, and Cu0.5Au0.5CN, which can be preferentially synthesized and epitaxially aligned onto various 2D materials. Here, we discover that Au1/2Ag1/2CN forms diamond-shaped nanocrystals epitaxially grown on pristine graphene surfaces. The nanocrystals synthesized by a simple drop-casting method are crystallographically aligned to lattice structures of the underlying graphene. Our experimental investigations on 3D structures and the synthesis conditions of the nanocrystals imply that the rhombic 2D geometries originate from different growth rates depending on orientations along and perpendicular to 1D molecular chains of Au1/2Ag1/2CN. We also perform in situ TEM observations showing that Au1/2Ag1/2CN nanocrystals are decomposed to Au and Ag alloy nanocrystals under electron beam irradiation. Our experimental results provide an additional example of 1D cyanide chain families that form ordered nanocrystals epitaxially aligned on 2D materials, and reveal basic physical characteristics of this rarely investigated nanomaterial.

Cold and heterogeneous T cell repertoire is associated with copy number aberrations and loss of immune genes in small-cell lung cancer.

Small-cell lung cancer (SCLC) is speculated to harbor complex genomic intratumor heterogeneity (ITH) associated with high recurrence rate and suboptimal response to immunotherapy. Here, using multi-region whole exome/T cell receptor (TCR) sequencing as well as immunohistochemistry, we reveal a rather homogeneous mutational landscape but extremely cold and heterogeneous TCR repertoire in limited-stage SCLC tumors (LS-SCLCs). Compared to localized non-small cell lung cancers, LS-SCLCs have similar predicted neoantigen burden and genomic ITH, but significantly colder and more heterogeneous TCR repertoire associated with higher chromosomal copy number aberration (CNA) burden. Furthermore, copy number loss of IFN-γ pathway genes is frequently observed and positively correlates with CNA burden. Higher mutational burden, higher T cell infiltration and positive PD-L1 expression are associated with longer overall survival (OS), while higher CNA burden is associated with shorter OS in patients with LS-SCLC.

Graphene Oxide-Supported Microwell Grids for Preparing Cryo-EM Samples with Controlled Ice Thickness.

Cryogenic-electron microscopy (cryo-EM) is the preferred method to determine 3D structures of proteins and to study diverse material systems that intrinsically have radiation or air sensitivity. Current cryo-EM sample preparation methods provide limited control over the sample quality, which limits the efficiency and high throughput of 3D structure analysis. This is partly because it is difficult to control the thickness of the vitreous ice that embeds specimens, in the range of nanoscale, depending on the size and type of materials of interest. Thus, there is a need for fine regulation of the thickness of vitreous ice to deliver consistent high signal-to-noise ratios for low-contrast biological specimens. Herein, an advanced silicon-chip-based device is developed which has a regular array of micropatterned holes with a graphene oxide (GO) window on freestanding silicon nitride (Six Ny ). Accurately regulated depths of micropatterned holes enable precise control of vitreous ice thickness. Furthermore, GO window with affinity for biomolecules can facilitate concentration of the sample molecules at a higher level. Incorporation of micropatterned chips with a GO window enhances cryo-EM imaging for various nanoscale biological samples including human immunodeficiency viral particles, groEL tetradecamers, apoferritin octahedral, aldolase homotetramer complexes, and tau filaments, as well as inorganic materials.

A Transformative Gold Patterning through Selective Laser Refining of Cyanide.

Gold is an essential noble metal for electronics, and its application area is increasing continuously through the introduction of gold nanoparticle ink that enables rapid prototyping and direct writing of gold electrodes on versatile substrates at a low temperature. However, the synthesis of gold nanoparticles has certain limitations involving high cost, long synthesis time, large waste of material, and frequent use of chemicals. In this study, we suggest simultaneous laser refining of gold cyanide and selective fabrication of gold electrodes directly on the substrate without a separate synthesis step. Gold cyanide is commonly the first product of gold from the primitive ore, and the gold can be extracted directly from the rapid photothermal decomposition of gold cyanide by the laser. It was confirmed that laser-induced thermocapillary force plays an important role in creating the continuous gold patterns by aligning the refined gold. The resultant gold electrodes exhibited a low resistivity analogous to the conventional direct writing method using nanoparticles, and the facile repair process of a damaged electrode was demonstrated as the proof-of-concept. The proposed transformative approach for gold patterning, distinguished from the previous top-down and bottom-up approaches, has the potential to replace the well-known techniques and provide a new branch of electrode manufacturing scheme.

Feasibility of implementing a national lung cancer screening program: Interim results from the Korean Lung Cancer Screening Project (K-LUCAS).

BACKGROUND: Lung cancer screening conducted in high-risk group using low-dose computer tomography (LDCT) has been reported as an effective method to reduce lung cancer mortality in two large randomized-control trials. However, the effectiveness is uncertain when lung cancer screening is expanded to a nationwide population-based program. METHODS: The Korean Lung Cancer Screening Project (K-LUCAS) is a single-arm cohort study that was conducted from February 2017 to evaluate the feasibility of implementing an organized national lung cancer screening program in Korea. High-risk population aged 55-74 years with more than a 30-pack-year smoking history was recruited. Smoking history was obtained from administering questionnaires at national health screening programs or public smoking cessation programs which are already established programs in Korea. The screening results were reported using the Lung Imaging Reporting and Data System (Lung-RADS), suggested by the American College of Radiology. K-LUCAS was performed by a network-based diagnosis supporting system using a computer-aided detection (CAD) program to maintain screening quality. Current smokers were provided with mandatory smoking counseling. RESULTS: Among 71,829 participants aged 50 years or older in the national health screening program, 5,975 (8.3%) were eligible for lung cancer screening. Among them, 1,062 (17.8%) refused to participate in K-LUCAS. Additionally, 779 participants were recruited in the smoking cessation program. Thus, a total of 5,692 eligible high-risk participants were recruited in this study. Among them, 865 (15.2%) had positive screening results, which requires a further examination; 529 (9.3%) had Lung-RADS category 3 (indeterminate), and 336 (5.9%) had category 4 (suspicious of lung cancer); 42 (0.7%) had confirmed lung cancer. Approximately 66.7% had early-stage lung cancer: 24 (57.1%), stage I and 4 (9.5%), stage II. Six (1.1%) patients developed complications at the time of diagnosis, including one death. The anxiety level related to cancer screening was low. Participation in screening encouraged motivation to quit smoking. CONCLUSIONS: K-LUCAS provided promising evidence supporting the implementation of a national lung cancer screening program to detect early stage lung cancer and promote smoking cessation for participants in Asian population.

Characterization of the Immune Landscape of EGFR-Mutant NSCLC Identifies CD73/Adenosine Pathway as a Potential Therapeutic Target.

INTRODUCTION: Lung adenocarcinomas harboring EGFR mutations do not respond to immune checkpoint blockade therapy and their EGFR wildtype counterpart. The mechanisms underlying this lack of clinical response have been investigated but remain incompletely understood. METHODS: We analyzed three cohorts of resected lung adenocarcinomas (Profiling of Resistance Patterns of Oncogenic Signaling Pathways in Evaluation of Cancer of Thorax, Immune Genomic Profiling of NSCLC, and The Cancer Genome Atlas) and compared tumor immune microenvironment of EGFR-mutant tumors to EGFR wildtype tumors, to identify actionable regulators to target and potentially enhance the treatment response. RESULTS: EGFR-mutant NSCLC exhibited low programmed death-ligand 1, low tumor mutational burden, decreased number of cytotoxic T cells, and low T cell receptor clonality, consistent with an immune-inert phenotype, though T cell expansion ex vivo was preserved. In an analysis of 75 immune checkpoint genes, the top up-regulated genes in the EGFR-mutant tumors (NT5E and ADORA1) belonged to the CD73/adenosine pathway. Single-cell analysis revealed that the tumor cell population expressed CD73, both in the treatment-naive and resistant tumors. Using coculture systems with EGFR-mutant NSCLC cells, T regulatory cell proportion was decreased with CD73 knockdown. In an immune-competent mouse model of EGFR-mutant lung cancer, the CD73/adenosine pathway was markedly up-regulated and CD73 blockade significantly inhibited tumor growth. CONCLUSIONS: Our work revealed that EGFR-mutant NSCLC has an immune-inert phenotype. We identified the CD73/adenosine pathway as a potential therapeutic target for EGFR-mutant NSCLC.

Reversible disorder-order transitions in atomic crystal nucleation.

Nucleation in atomic crystallization remains poorly understood, despite advances in classical nucleation theory. The nucleation process has been described to involve a nonclassical mechanism that includes a spontaneous transition from disordered to crystalline states, but a detailed understanding of dynamics requires further investigation. In situ electron microscopy of heterogeneous nucleation of individual gold nanocrystals with millisecond temporal resolution shows that the early stage of atomic crystallization proceeds through dynamic structural fluctuations between disordered and crystalline states, rather than through a single irreversible transition. Our experimental and theoretical analyses support the idea that structural fluctuations originate from size-dependent thermodynamic stability of the two states in atomic clusters. These findings, based on dynamics in a real atomic system, reshape and improve our understanding of nucleation mechanisms in atomic crystallization.