Pilot validation of on-field STR typing and human identity testing by MinION nanopore sequencing.

Nanopore sequencing technology has broad application prospects in forensic medicine due to its small size, portability, fast speed, real-time result analysis capabilities, single-molecule sequencing abilities, and simple operation. Here, we demonstrate for the first time that nanopore sequencing platforms can be used to identify individuals in the field. Through scientific and reasonable design, a nanopore MinION MK1B device and other auxiliary devices are integrated into a portable detection box conducive to individual identification at the accident site. Individual identification of 12 samples could be completed within approximately 24 h by jointly detecting 23 short tandem repeat (STR) loci. Through double-blinded experiments, the genotypes of 49 samples were successfully determined, and the accuracy of the STR genotyping was verified by the gold standard. Specifically, the typing success rate for 1150 genotypes was 95.3%, and the accuracy rate was 86.87%. Although this study focused primarily on demonstrating the feasibility of full-process testing, it can be optimistically predicted that further improvements in bioinformatics workflows and nanopore sequencing technology will help enhance the feasibility of Oxford Nanopore Technologies equipment for real-time individual identification at accident sites.

Partners in Crime: Neutrophil-CTC Collusion in Metastasis.

A recent study in Nature (Szczerba et al. 2019;566:553-557) reports that the association of neutrophils with circulating tumor cells (CTCs) in the blood of patients with breast cancer can promote CTC proliferation and metastasis. These findings reveal a new mechanism by which the innate immune system may be co-opted to drive tumor progression.

Long Noncoding RNA p53-Stabilizing and Activating RNA Promotes p53 Signaling by Inhibiting Heterogeneous Nuclear Ribonucleoprotein K deSUMOylation and Suppresses Hepatocellular Carcinoma.

To identify hepatocellular carcinoma (HCC)-implicated long noncoding RNAs (lncRNAs), we performed an integrative omics analysis by integrating mRNA and lncRNA expression profiles in HCC tissues. We identified a collection of candidate HCC-implicated lncRNAs. Among them, we demonstrated that an lncRNA, which is named as p53-stabilizing and activating RNA (PSTAR), inhibits HCC cell proliferation and tumorigenicity through inducing p53-mediated cell cycle arrest. We further revealed that PSTAR can bind to heterogeneous nuclear ribonucleoprotein K (hnRNP K) and enhance its SUMOylation and thereby strengthen the interaction between hnRNP K and p53, which ultimately leads to the accumulation and transactivation of p53. PSTAR is down-regulated in HCC tissues, and the low PSTAR expression predicts poor prognosis in patients with HCC, especially those with wild-type p53. Conclusion: This study sheds light on the tumor suppressor role of lncRNA PSTAR, a modulator of the p53 pathway, in HCC.

Assembly and turnover of short actin filaments by the formin INF2 and profilin.

INF2 (inverted formin 2) is a formin protein with unique biochemical effects on actin. In addition to the common formin ability to accelerate actin nucleation and elongation, INF2 can also sever filaments and accelerate their depolymerization. Although we understand key attributes of INF2-mediated severing, we do not understand the mechanism by which INF2 accelerates depolymerization subsequent to severing. Here, we show that INF2 can create short filaments (<60 nm) that continuously turn over actin subunits through a combination of barbed end elongation, severing, and WH2 motif-mediated depolymerization. This pseudo-steady state condition occurs whether starting from actin filaments or monomers. The rate-limiting step of the cycle is nucleotide exchange of ADP for ATP on actin monomers after release from the INF2/actin complex. Profilin addition has two effects: 1) to accelerate filament turnover 6-fold by accelerating nucleotide exchange and 2) to shift the equilibrium toward polymerization, resulting in longer filaments. In sum, our findings show that the combination of multiple interactions of INF2 with actin can work in concert to increase the ATP turnover rate of actin. Depending on the ratio of INF2:actin, this increased flux can result in rapid filament depolymerization or maintenance of short filaments. We also show that high concentrations of cytochalasin D accelerate ATP turnover by actin but through a different mechanism from that of INF2.

Protein engineering of the N-terminus of NEMO: structure stabilization and rescue of IKKß binding.

NEMO is a scaffolding protein that, together with the catalytic subunits IKKα and IKKß, plays an essential role in the formation of the IKK complex and in the activation of the canonical NF-κB pathway. Rational drug design targeting the IKK-binding site on NEMO would benefit from structural insight, but to date, the determination of the structure of unliganded NEMO has been hindered by protein size and conformational heterogeneity. Here we show how the utilization of a homodimeric coiled-coil adaptor sequence stabilizes the minimal IKK-binding domain NEMO(44-111) and furthers our understanding of the structural requirements for IKK binding. The engineered constructs incorporating the coiled coil at the N-terminus, C-terminus, or both ends of NEMO(44-111) present high thermal stability and cooperative melting and, most importantly, restore IKKß binding affinity. We examined the consequences of structural content and stability by circular dichoism and nuclear magnetic resonance (NMR) and measured the binding affinity of each construct for IKKß(701-745) in a fluorescence anisotropy binding assay, allowing us to correlate structural characteristics and stability to binding affinity. Our results provide a method for engineering short stable NEMO constructs to be suitable for structural characterization by NMR or X-ray crystallography. Meanwhile, the rescuing of the binding affinity implies that a preordered IKK-binding region of NEMO is compatible with IKK binding, and the conformational heterogeneity observed in NEMO(44-111) may be an artifact of the truncation.

Human-like adrenal features in Chinese tree shrews revealed by multi-omics analysis of adrenal cell populations and steroid synthesis.

The Chinese tree shrew ( Tupaia belangeri chinensis) has emerged as a promising model for investigating adrenal steroid synthesis, but it is unclear whether the same cells produce steroid hormones and whether their production is regulated in the same way as in humans. Here, we comprehensively mapped the cell types and pathways of steroid metabolism in the adrenal gland of Chinese tree shrews using single-cell RNA sequencing, spatial transcriptome analysis, mass spectrometry, and immunohistochemistry. We compared the transcriptomes of various adrenal cell types across tree shrews, humans, macaques, and mice. Results showed that tree shrew adrenal glands expressed many of the same key enzymes for steroid synthesis as humans, including CYP11B2, CYP11B1, CYB5A, and CHGA. Biochemical analysis confirmed the production of aldosterone, cortisol, and dehydroepiandrosterone but not dehydroepiandrosterone sulfate in the tree shrew adrenal glands. Furthermore, genes in adrenal cell types in tree shrews were correlated with genetic risk factors for polycystic ovary syndrome, primary aldosteronism, hypertension, and related disorders in humans based on genome-wide association studies. Overall, this study suggests that the adrenal glands of Chinese tree shrews may consist of closely related cell populations with functional similarity to those of the human adrenal gland. Our comprehensive results (publicly available at http://gxmujyzmolab.cn:16245/scAGMap/) should facilitate the advancement of this animal model for the investigation of adrenal gland disorders.

Short-term chromium-stress-induced alterations in the maize leaf proteome.

Soil contamination by chromium (Cr) has become an increasing problem worldwide as a result of extensive industrial activities. Chromium, especially hexavalent Cr, impairs the growth and productivity of plants. Although it has been proposed that plants could modify their metabolism to adapt to Cr stress by reprogramming the expression of genes, especially those related to the antioxidant system, damage response, and electron transport chain, evidence at the protein expression level is lacking. To better understand the precise mechanisms underlying Cr phytoxicity and the plant response to Cr exposure, the time-course of changes in the protein expression profile induced by short-term hexavalent Cr exposure (1, 6 and 24 h) were analyzed in maize leaves. Among the over 1200 protein spots detected reproducibly by two-dimensional electrophoresis (2-DE), 60 were found to be differentially accumulated during Cr stress treatment. Of the Cr-regulated proteins, 58 were identified using tandem mass spectrometry (MS/MS). The Cr-regulated proteins identified were mainly involved in ROS detoxification and defense responses (26%), photosynthesis and chloroplast organization (22%), post-transcriptional processing of mRNA and rRNA (12%), protein synthesis and folding (10%), the DNA damage response (5%), and the cytoskeleton (3%). The possible involvement of these Cr stress-responsive proteins in Cr phytoxicity and the plant response to Cr exposure in maize is discussed, taking into consideration the information available from other plant models. Our results provide preliminary evidence that will facilitate understanding the molecular mechanisms underlying Cr toxicity in maize.

The Notch1/Hes1 signaling pathway affects autophagy by adjusting DNA methyltransferases expression in a valproic acid-induced autism spectrum disorder model.

As a pervasive neurodevelopmental disease, autism spectrum disorder (ASD) is caused by both hereditary and environmental elements. Research has demonstrated the functions of the Notch pathway and DNA methylation in the etiology of ASD. DNA methyltransferases DNMT3 and DNMT1 are responsible for methylation establishment and maintenance, respectively. In this study, we aimed to explore the association of DNA methyltransferases with the Notch pathway in ASD. Our results showed Notch1 and Hes1 were upregulated, while DNMT3A and DNMT3B were downregulated at the protein level in the prefrontal cortex (PFC), hippocampus (HC) and cerebellum (CB) of VPA-induced ASD rats compared with Control (Con) group. However, the protein levels of DNMT3A and DNMT3B were augmented after treatment with 3,5-difluorophenacetyl-L-alanyl-S-phenylglycine-2-butyl ester (DAPT), suggesting that abnormal Notch pathway activation may affect the expression of DNMT3A and DNMT3B. Besides, our previous findings revealed that the Notch pathway may participate in development of ASD by influencing autophagy. Therefore, we hypothesized the Notch pathway adjusts autophagy and contributes to ASD by affecting DNA methyltransferases. Our current results showed that after receiving the DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine (5-Aza-2'dc), the VPA + DAPT+5-Aza-2'dc (V + D + Aza) group exhibited reduced social interaction ability and increased stereotyped behaviors, and decreased expression of DNMT3A, DNMT3B and autophagy-related proteins, but did not show changes in Notch1 and Hes1 protein levels. Our results indicated that the Notch1/Hes1 pathway may adjust DNMT3A and DNMT3B expression and subsequently affect autophagy in the occurrence of ASD, providing new insight into the pathogenesis of ASD.

Mitogenomic phylogenies suggest the resurrection of the subfamily Porrocaecinae and provide insights into the systematics of the superfamily Ascaridoidea (Nematoda: Ascaridomorpha), with the description of a new species of Porrocaecum.

BACKGROUND: The family Toxocaridae is a group of zooparasitic nematodes of veterinary, medical and economic significance. However, the evolutionary relationship of Porrocaecum and Toxocara, both genera currently classified in Toxocaridae, and the monophyly of the Toxocaridae remain under debate. Moreover, the validity of the subgenus Laymanicaecum in the genus Porrocaecum is open to question. Due to the scarcity of an available genetic database, molecular identification of Porrocaecum nematodes is still in its infancy. METHODS: A number of Porrocaecum nematodes collected from the Eurasian marsh harrier Circus aeruginosus (Linnaeus) (Falconiformes: Accipitridae) in the Czech Republic were identified using integrated morphological methods (light and scanning electron microscopy) and molecular techniques (sequencing and analyzing the nuclear 18S, 28S and ITS regions). The complete mitochondrial genomes of the collected nematode specimens and of Porrocaecum (Laymanicaecum) reticulatum (Linstow, 1899) were sequenced and annotated for the first time. Phylogenetic analyses of ascaridoid nematodes based on the amino acid sequences of 12 protein-coding genes of mitochondrial genomes were performed using maximum likelihood and Bayesian inference. RESULTS: A new species of Porrocaecum, named P. moraveci n. sp., is described based on the morphological and genetic evidence. The mitogenomes of P. moraveci n. sp. and P. reticulatum both contain 36 genes and are 14,517 and 14,210 bp in length, respectively. Comparative mitogenomics revealed that P. moraveci n. sp. represents the first known species with three non-coding regions and that P. reticulatum has the lowest overall A + T content in the mitogenomes of ascaridoid nematodes tested to date. Phylogenetic analyses showed the representatives of Toxocara clustered together with species of the family Ascarididae rather than with Porrocaecum and that P. moraveci n. sp. is a sister to P. reticulatum. CONCLUSIONS: The characterization of the complete mitochondrial genomes of P. moraveci n. sp. and P. reticulatum is reported for the first time. Mitogenomic phylogeny analyses indicated that the family Toxocaridae is non-monophyletic and that the genera Porrocaecum and Toxocara do not have an affinity. The validity of the subgenus Laymanicaecum in Porrocaecum was also rejected. Our results suggest that: (i) Toxocaridae should be degraded to a subfamily of the Ascarididae that includes only the genus Toxocara; and (ii) the subfamily Porrocaecinae should be resurrected to include only the genus Porrocaecum. The present study enriches the database of ascaridoid mitogenomes and provides a new insight into the systematics of the superfamily Ascaridoidea.

Integrative Single-Cell Analysis Reveals Transcriptional and Epigenetic Regulatory Features of Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) frequently features a high level of tumor heterogeneity. Elucidating the chromatin landscape of ccRCC at the single-cell level could provide a deeper understanding of the functional states and regulatory dynamics underlying the disease. Here, we performed single-cell RNA sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin using sequencing (scATAC-seq) on 19 ccRCC samples, and whole-exome sequencing was used to understand the heterogeneity between individuals. Single-cell transcriptome and chromatin accessibility maps of ccRCC were constructed to reveal the regulatory characteristics of different tumor cell subtypes in ccRCC. Two long noncoding RNAs (RP11-661C8.2 and CTB-164N12.1) were identified that promoted the invasion and migration of ccRCC, which was validated with in vitro experiments. Taken together, this study comprehensively characterized the gene expression and DNA regulation landscape of ccRCC, which could provide new insights into the biology and treatment of ccRCC. SIGNIFICANCE: A comprehensive analysis of gene expression and DNA regulation in ccRCC using scATAC-seq and scRNA-seq reveals the DNA regulatory programs of ccRCC at the single-cell level.

Toll-Like Receptors Serve as Biomarkers for Early Diagnosis and Prognosis Assessment of Kidney Renal Clear Cell Carcinoma by Influencing the Immune Microenvironment: Comprehensive Bioinformatics Analysis Combined With Experimental Validation.

Background: Toll-like receptors (TLRs) are important initiators of innate and acquired immune responses. However, its role in kidney renal clear cell carcinoma (KIRC) remains unclear. Methods: TLRs and their relationships with KIRC were studied in detail by ONCOMINE, UALCAN, GEPIA, cBioPortal, GeneMANIA, FunRich, LinkedOmics, TIMER and TRRUST. Moreover, we used clinical samples to verify the expressions of TLR3 and TLR4 in early stage of KIRC by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), flow cytometry (FC) and immunohistochemistry (IHC). Results: The expression levels of TLRs in KIRC were generally different compared with adjacent normal tissues. Moreover, the expressions of TLR3 and TLR4 elevated significantly in the early stage of KIRC. Overexpressions of TLR1, TLR3, TLR4 and TLR8 in KIRC patients were associated with longer overall survival (OS), while inhibition of TLR9 expression was related to longer OS. Additionally, overexpressions of TLR1, TLR3 and TLR4 in KIRC patients were associated with longer disease free survival (DFS). There were general genetic alterations and obvious co-expression correlation of TLRs in KIRC. The PPI network between TLRs was rather complex, and the key gene connecting the TLRs interaction was MYD88. The GO analysis and KEGG pathway analysis indicated that TLRs were closely related to adaptive immunity, innate immunity and other immune-related processes. RELA, NFKB1, IRF8, IRF3 and HIF1A were key transcription factors regulating the expressions of TLRs. What's more, the expression levels of all TLRs in KIRC were positively correlated with the infiltration levels of dendritic cells, macrophages, neutrophils, B cells, CD4+ T cells and CD8+ T cells. Finally, the results of RT-qPCR, FC and IHC confirmed that TLR3 and TLR4 were significantly elevated in the early stage of KIRC. Conclusion: The occurrence and development of KIRC are closely related to TLRs, and TLRs have the potential to be early diagnostic biomarkers of KIRC and biomarkers for judging the prognosis and immune status of KIRC. This study may provide new insights into the selection of KIRC immunotherapy targets.

A spatiotemporal steroidogenic regulatory network in human fetal adrenal glands and gonads.

Human fetal adrenal glands produce substantial amounts of dehydroepiandrosterone (DHEA), which is one of the most important precursors of sex hormones. However, the underlying biological mechanism remains largely unknown. Herein, we sequenced human fetal adrenal glands and gonads from 7 to 14 gestational weeks (GW) via 10× Genomics single-cell transcriptome techniques, reconstructed their location information by spatial transcriptomics. Relative to gonads, adrenal glands begin to synthesize steroids early. The coordination among steroidogenic cells and multiple non-steroidogenic cells promotes adrenal cortex construction and steroid synthesis. Notably, during the window of sexual differentiation (8-12 GW), key enzyme gene expression shifts to accelerate DHEA synthesis in males and cortisol synthesis in females. Our research highlights the robustness of the action of fetal adrenal glands on gonads to modify the process of sexual differentiation.

Single-Cell RNA-seq Identification of the Cellular Molecular Characteristics of Sporadic Bilateral Clear Cell Renal Cell Carcinoma.

Bilateral renal cell carcinoma (RCC) is a rare disease that can be classified as either familial or sporadic. Studying the cellular molecular characteristics of sporadic bilateral RCC is important to provide guidance for clinical treatment. Cellular molecular characteristics can be expressed at the RNA level, especially at the single-cell degree. Single-cell RNA sequencing (scRNA-seq) was performed on bilateral clear cell RCC (ccRCC). A total of 3,575 and 3,568 high-quality single-cell transcriptome data were captured from the left and right tumour tissues, respectively. Gene characteristics were identified by comparing left and right tumours at the scRNA level. The complex cellular environment of bilateral ccRCC was presented by using scRNA-seq. Single-cell transcriptomic analysis revealed high similarity in gene expression among most of the cell types of bilateral RCCs but significant differences in gene expression among different site tumour cells. Additionally, the potential biological function of different tumour cell types was determined by gene ontology (GO) analysis. The transcriptome characteristics of tumour tissues in different locations at the single-cell transcriptome level were revealed through the scRNA-seq of bilateral sporadic ccRCC. This work provides new insights into the diagnosis and treatment of bilateral RCC.

Single-Cell RNA Sequencing in Multiple Pathologic Types of Renal Cell Carcinoma Revealed Novel Potential Tumor-Specific Markers.

BACKGROUND: Renal cell carcinoma (RCC) is the most common type of kidney cancer. Studying the pathogenesis of RCC is particularly important, because it could provide a direct guide for clinical treatment. Given that tumor heterogeneity is probably reflected at the mRNA level, the study of mRNA in RCC may reveal some potential tumor-specific markers, especially single-cell RNA sequencing (scRNA-seq). METHODS: We performed an exploratory study on three pathological types of RCC with a small sample size. This study presented clear-cell RCC (ccRCC), type 2 pRCC, and chRCC in a total of 30,263 high-quality single-cell transcriptome information from three pathological types of RCC. In addition, scRNA-seq was performed on normal kidneys. Tumor characteristics were well identified by the comparison between different pathological types of RCC and normal kidneys at the scRNA level. RESULTS: Some new tumor-specific markers for different pathologic types of RCC, such as SPOCK1, PTGIS, REG1A, CP and SPAG4 were identified and validated. We also discovered that NDUFA4L2 both highly expressed in tumor cells of ccRCC and type 2 pRCC. The presence of two different types of endothelial cells in ccRCC and type 2 pRCC was also identified and verified. An endothelial cell in ccRCC may be associated with fibroblasts and significantly expressed fibroblast markers, such as POSTN and COL3A1. At last, by applying scRNA-seq results, the activation of drug target pathways and sensitivity to drug responses was predicted in different pathological types of RCC. CONCLUSIONS: Taken together, these findings considerably enriched the single-cell transcriptomic information for RCC, thereby providing new insights into the diagnosis and treatment of RCC.

MAML1-Dependent Notch-Responsive Genes Exhibit Differing Cofactor Requirements for Transcriptional Activation.

Mastermind proteins are required for transcription of Notch target genes, yet the molecular basis for mastermind function remains incompletely understood. Previous work has shown that Notch can induce transcriptional responses by binding to promoters but more often by binding to enhancers, with HES4 and DTX1 as representative mammalian examples of promoter and enhancer responsiveness, respectively. Here, we show that mastermind dependence of the Notch response at these loci is differentially encoded in Jurkat T-cell acute lymphoblastic leukemia (T-ALL) cells. Knockout of Mastermind-like 1 (MAML1) eliminates Notch-responsive activation of both these genes, and reduced target gene expression is accompanied by a decrease in H3K27 acetylation, consistent with the importance of MAML1 for p300 activity. Add-back of MAML1 variants in knockout cells identifies residues 151 to 350 of MAML1 as essential for expression of either Notch-responsive gene. Fusion of the Notch-binding region of MAML1 to the histone acetyltransferase (HAT) domain of p300 rescues expression of HES4 but not DTX1, suggesting that an additional activity of MAML1 is needed for gene induction at a distance. Together, these studies establish the functional importance of the MAML1 region from residues 151 to 350 for Notch-dependent transcriptional induction and reveal differential requirements for MAML1-dependent recruitment activities at different Notch-responsive loci, highlighting the molecular complexity of Notch-stimulated transcription.

Chromatin Looping Shapes KLF5-Dependent Transcriptional Programs in Human Epithelial Cancers.

Activation of transcription factors is a key driver event in cancer. We and others have recently reported that the Krüppel-like transcription factor KLF5 is activated in multiple epithelial cancer types including squamous cancer and gastrointestinal adenocarcinoma, yet the functional consequences and the underlying mechanisms of this activation remain largely unknown. Here we demonstrate that activation of KLF5 results in strongly selective KLF5 dependency for these cancer types. KLF5 bound lineage-specific regulatory elements and activated gene expression programs essential to cancer cells. HiChIP analysis revealed that multiple distal KLF5 binding events cluster and synergize to activate individual target genes. Immunoprecipitation-mass spectrometry assays showed that KLF5 interacts with other transcription factors such as TP63 and YAP1, as well as the CBP/EP300 acetyltransferase complex. Furthermore, KLF5 guided the CBP/EP300 complex to increase acetylation of H3K27, which in turn enhanced recruitment of the bromodomain protein BRD4 to chromatin. The 3D chromatin architecture aggregated KLF5-dependent BRD4 binding to activate polymerase II elongation at KLF5 target genes, which conferred a transcriptional vulnerability to proteolysis-targeting chimera-induced degradation of BRD4. Our study demonstrates that KLF5 plays an essential role in multiple epithelial cancers by activating cancer-related genes through 3D chromatin loops, providing an evidence-based rationale for targeting the KLF5 pathway. SIGNIFICANCE: An integrative 3D genomics methodology delineates mechanisms underlying the function of KLF5 in multiple epithelial cancers and suggests potential strategies to target cancers with aberrantly activated KLF5.

Quantitative proteomics identifies a plasma multi-protein model for detection of hepatocellular carcinoma.

More efficient biomarkers are needed to facilitate the early detection of hepatocellular carcinoma (HCC). We aimed to identify candidate biomarkers for HCC detection by proteomic analysis. First, we performed a global proteomic analysis of 10 paired HCC and non-tumor tissues. Then, we validated the top-ranked proteins by targeted proteomic analyses in another tissue cohort. At last, we used enzyme-linked immunosorbent assays to validate the candidate biomarkers in multiple serum cohorts including HCC cases (HCCs), cirrhosis cases (LCs), and normal controls (NCs). We identified and validated 33 up-regulated proteins in HCC tissues. Among them, eight secretory or membrane proteins were further evaluated in serum, revealing that aldo-keto reductase family 1 member B10 (AKR1B10) and cathepsin A (CTSA) can distinguish HCCs from LCs and NCs. The area under the curves (AUCs) were 0.891 and 0.894 for AKR1B10 and CTSA, respectively, greater than that of alpha-fetoprotein (AFP; 0.831). Notably, combining the three proteins reached an AUC of 0.969, which outperformed AFP alone (P < 0.05). Furthermore, the serum AKR1B10 levels dramatically decreased after surgery. AKR1B10 and CTSA are potential serum biomarkers for HCC detection. The combination of AKR1B10, CTSA, and AFP may improve the HCC diagnostic efficacy.

MYC Drives Temporal Evolution of Small Cell Lung Cancer Subtypes by Reprogramming Neuroendocrine Fate.

Small cell lung cancer (SCLC) is a neuroendocrine tumor treated clinically as a single disease with poor outcomes. Distinct SCLC molecular subtypes have been defined based on expression of ASCL1, NEUROD1, POU2F3, or YAP1. Here, we use mouse and human models with a time-series single-cell transcriptome analysis to reveal that MYC drives dynamic evolution of SCLC subtypes. In neuroendocrine cells, MYC activates Notch to dedifferentiate tumor cells, promoting a temporal shift in SCLC from ASCL1+ to NEUROD1+ to YAP1+ states. MYC alternatively promotes POU2F3+ tumors from a distinct cell type. Human SCLC exhibits intratumoral subtype heterogeneity, suggesting that this dynamic evolution occurs in patient tumors. These findings suggest that genetics, cell of origin, and tumor cell plasticity determine SCLC subtype.

[Preparation of mixed-mode stationary phase for high performance liquid chromatography with ground hybrid silica monolithic material].

With polyethylene glycol as a porogen, vinyltrimethoxysilane (VTMS) and tetramethoxysilane (TMOS) as silica precursors, a hybrid silica monolithic material was obtained under the catalysis of acetic acid and thermally decomposed urea. The silica monolithic material was ground by a ballmill, treated with tris(hydroxymethyl)aminomethane (Tris), then washed and dried to obtain silica particles with particle size~3 µm. The effects of different reaction conditions on the particle size, surface morphology and dispersibility of silica particles were investigated. When the volume ratio of TMOS to VTMS was 3:1, it was observed that silica particles with a pore diameter of 7.5 nm and a specific surface area of 245 m2/g were obtained. The resultant silica particles were modified by binding with chlorodimethyloctadecylsilane (C18) and by the thiol-ene click reaction to obtain a mixed-mode type stationary phase. The test results showed that the silica packing materials prepared in this work has certain applicability.

One-pot synthesis of polypyrrole nanoparticles with tunable photothermal conversion and drug loading capacity.

With an excellent near-infrared (NIR) light-responsive property, polypyrrole (PPy) nanoparticle has emerged as a promising NIR photothermal transducing agent for tumor photothermal therapy (PTT). Herein, we reported the PVP mediated one-pot synthesis of colloidal stable and biocompatible PPy nanoparticles (PPy-PVP NPs) for combined tumor photothermal-chemotherapy. The influence of molecular weight and PVP concentration on the spectroscopic characteristic, photothermal feature, drug loading performance, and antitumor efficiency of the resultant PPy-PVP NPs was systematically studied. By choosing PVP with a molecular weight of 360 kDa (concentration of 5 mg/mL) as the template and surface modifier during the synthesis, PPy-PVP NPs with optimal spectroscopic characteristic, photothermal feature, drug loading performance, and antitumor efficiency were synthesized. Findings in this study are anticipated to provide an in-depth understanding of the important character of surface engineering in the rational design and biomedical applications of PPy NPs.