Long and Short-Term Effect of mTOR Regulation on Cerebral Organoid Growth and Differentiations.

BACKGROUND: The mammalian target of rapamycin (mTOR) signaling is critical for the maintenance and differentiation of neurogenesis, and conceivably for many other brain developmental processes. However, in vivo studies of mTOR functions in the brain are often hampered due to the essential role of the associated signaling in brain development. METHODS: We monitored the long- and short-term effects of mTOR signaling regulation on cerebral organoids growth, differentiation and function using an mTOR inhibitor (everolimus) and an mTOR activator (MHY1485). RESULTS: Short-term treatment with MHY1485 induced faster organoid growth and differentiation, while long-term treatment induced the maturation of cerebral organoids. CONCLUSION: These data suggest that the optimal activity of mTOR is crucial in maintaining normal brain development, and its role is not confined to the early neurogenic phase of brain development.

DW71177: A novel [1,2,4]triazolo[4,3-a]quinoxaline-based potent and BD1-Selective BET inhibitor for the treatment of acute myeloid leukemia.

The bromodomain and extraterminal domain (BET) family proteins recognize acetyl-lysine (Kac) at the histone tail through two tandem bromodomains, i.e., BD1 and BD2, to regulate gene expression. BET proteins are attractive therapeutic targets in cancer due to their involvement in oncogenic transcriptional activation, and bromodomains have defined Kac-binding pockets. Here, we present DW-71177, a potent BET inhibitor that selectively interacts with BD1 and exhibits strong antileukemic activity. X-ray crystallography, isothermal titration calorimetry, and molecular dynamic studies have revealed the robust and specific binding of DW-71177 to the Kac-binding pocket of BD1. DW-71177 effectively inhibits oncogenes comparable to the pan-BET inhibitor OTX-015, but with a milder impact on housekeeping genes. It efficiently blocks cancer-associated transcriptional changes by targeting genes that are highly enriched with BRD4 and histone acetylation marks, suggesting that BD1-selective targeting could be an effective and safe therapeutic strategy against leukemia.

Integrative Analyses Reveal the Anticancer Mechanisms and Sensitivity Markers of the Next-Generation Hypomethylating Agent NTX-301.

Epigenetic dysregulation characterized by aberrant DNA hypermethylation is a hallmark of cancer, and it can be targeted by hypomethylating agents (HMAs). Recently, we described the superior therapeutic efficacy of a novel HMA, namely, NTX-301, when used as a monotherapy and in combination with venetoclax in the treatment of acute myeloid leukemia. Following a previous study, we further explored the therapeutic properties of NTX-301 based on experimental investigations and integrative data analyses. Comprehensive sensitivity profiling revealed that NTX-301 primarily exerted anticancer effects against blood cancers and exhibited improved potency against a wide range of solid cancers. Subsequent assays showed that the superior efficacy of NTX-301 depended on its strong effects on cell cycle arrest, apoptosis, and differentiation. Due to its superior efficacy, low doses of NTX-301 achieved sufficiently substantial tumor regression in vivo. Multiomics analyses revealed the mechanisms of action (MoAs) of NTX-301 and linked these MoAs to markers of sensitivity to NTX-301 and to the demethylation activity of NTX-301 with high concordance. In conclusion, our findings provide a rationale for currently ongoing clinical trials of NTX-301 and will help guide the development of novel therapeutic options for cancer patients.

Generation of human tonsil epithelial organoids as an ex vivo model for SARS-CoV-2 infection.

The palatine tonsils (hereinafter referred to as "tonsils") serve as a reservoir for viral infections and play roles in the immune system's first line of defense. The aims of this study were to establish tonsil epithelial cell-derived organoids and examine their feasibility as an ex vivo model for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The tonsil organoids successfully recapitulated the key characteristics of the tonsil epithelium, including cellular composition, histologic properties, and biomarker distribution. Notably, the basal layer cells of the organoids express molecules essential for SARS-CoV-2 entry, such as angiotensin-converting enzyme 2 (ACE2), transmembrane serine protease 2 (TMPRSS2) and furin, being susceptible to the viral infection. Changes in the gene expression profile in tonsil organoids revealed that 395 genes associated with oncostatin M signaling and lipid metabolism were highly upregulated within 72 h after SARS-CoV-2 infection. Notably, remdesivir suppressed the viral RNA copy number in organoid culture supernatants and intracellular viral protein levels in a dose-dependent manner. Here, we suggest that tonsil epithelial organoids could provide a preclinical and translational research platform for investigating SARS-CoV-2 infectivity and transmissibility or for evaluating antiviral candidates.

The role of TRIM51 as a multipurpose biomarker in melanoma.

BACKGROUND: Identification of molecular biomarkers through comprehensive multiomics analyses is essential for the implementation of precision medicine. METHODS: To evaluate the association of each gene with sensitivity or resistance to multiple drugs, we adopted a quantitative metric, the drug response score (DRS), and examined the pharmacotranscriptomic characteristics of genes. We performed comprehensive integrative analyses of multiple independent datasets [Cancer Therapeutics Response Portal (CTRP), Profiling Relative Inhibition Simultaneously in Mixtures (PRISM), Gene Expression Omnibus (GEO), and The Cancer Genome Atlas (TCGA)] in the process of screening, proof, and validation of our findings. RESULTS: Through a comprehensive pharmacotranscriptomics approach, we found that TRIM51-high cancer cell lines (CCLs) are highly sensitive to multiple BRAF-MEK inhibitors. The association was preserved even when the analysis was restricted to BRAF-mutant melanoma CCLs, indicating the potential of TRIM51 as a BRAF mutation-independent predictive biomarker. Moreover, the expression level of TRIM51 faithfully represented the degree of post-treatment activity and resistance upon treatment with BRAF-MEK inhibitors both in vitro and in clinical situations, suggesting its application as a surrogate marker for the pharmacological activity of BRAF-MEK inhibitors. In addition, the high expression levels of TRIM51 were significantly associated with worse prognosis and immuno-resistance features in melanoma, indicating its role as a prognostic marker. CONCLUSIONS: Our findings revealed a novel role for TRIM51 as a multiuse biomarker in melanoma. The strategy of this study will motivate the development of novel clinical markers.

A guide for bioinformaticians: 'omics-based drug discovery for precision oncology.

Bioinformatics-centric drug development is inevitable in the era of precision medicine. Clinical 'omics information, including genomics, epigenomics, transcriptomics, and proteomics, provides the most comprehensive molecular landscape in which each patient's pathological history is delineated. Hence, the capability of bioinformaticians to manage integrative 'omics data is crucial to current drug development. Bioinformatics can accelerate drug development from initial time-consuming discoveries to the clinical stage by providing information-guided solutions. However, many bioinformaticians do not have opportunities to participate in drug discovery programs. As a starting point for bioinformaticians with no prior drug development experience, here we discuss bioinformatics applications during drug development with a focus on working-level omics-based methodologies.

ONECUT2 upregulation is associated with CpG hypomethylation at promoter-proximal DNA in gastric cancer and triggers ACSL5.

Many studies have focused on global hypomethylation or hypermethylation of tumor suppressor genes, but less is known about the impact of promoter hypomethylation of oncogenes. We previously showed that promoter methylation may gradually increase or decrease during the transition from gastric mucosa (GM) to intestinal metaplasia (IM) to gastric cancer (GC). In our study, we focused on regional CpG hypomethylation of the promoter-proximal DNA of the transcription factor ONECUT2 (OC2) in IM and GC cells. We validated the hypomethylation of promoter-proximal DNA of OC2 in 160 primary GCs, in which methylation level correlated negatively with OC2 mRNA level. IM and GC cells stained positively for OC2, whereas GM cells did not. Stable transfection of OC2 in GC cells promoted colony formation, cell migration, invasion and proliferation. Moreover, OC2 knockdown with a short hairpin RNA suppressed tumorigenesis in nude mice. In addition, chromatin immunoprecipitation coupled with DNA sequencing and RNA-seq analyses revealed that OC2 triggered ACSL5, which is strongly expressed in IM of the stomach but not in GM, indicating that OC2 and ACSL5 are early-stage biomarkers for GC. We also observed a high correlation between the levels of OC2 and ACSL5 mRNAs in the GENT database These results suggest that epigenetic alteration of OC2 upregulates its expression, which then activates ACSL5; thus, OC2 is induced in IM by epigenetic alteration and triggers ACSL5 expression, and thus OC2 and ACSL5 may cooperatively promote intestinal differentiation and GC progression.

ANKRD9 is associated with tumor suppression as a substrate receptor subunit of ubiquitin ligase.

BACKGROUND: Human ANKRD9 (ankyrin repeat domain 9) expression is altered in some cancers. METHODS: We tested genetic association of ANKRD9 with gastric cancer susceptibility and examined functional association of ANKRD9 with altered proliferation of MKN45 gastric cancer cells. We then identified ANKRD9-binding partners in HEK 293 embryonic kidney cells using quantitative proteomics, western blotting and complex reconstitution assays. We finally demonstrated ANKRD9's role of recognizing substrates for ubiquitination using in vitro ubiquitylation assay. RESULTS: ANKRD9 is associated with cancer susceptibility in a comparison of single-nucleotide polymorphisms between 1092 gastric cancer patients and 1206 healthy controls. ANKRD9 depletion accelerates tumor progression by increasing cellular proliferation, piling up, and anchorage-independent growth of MKN45 cells. We discovered that ANKRD9 is a ubiquitin ligase substrate receptor subunit and has an anti-proliferative activity. ANKRD9 associates with CUL5 (not CUL2), ELOB, ELOC, and presumably RNF7 subunits, which together assemble into a cullin-RING superfamily E3 ligase complex. ANKRD9 belongs to the ASB family of proteins, which are characterized by the presence of ankyrin repeats and a SOCS box. In addition to its interactions with the other E3 ligase subunits, ANKRD9 interacts with two isoforms of inosine monophosphate dehydrogenase (IMPDH). These IMPDH isoforms are cognate substrates of the ANKRD9-containing E3 enzyme, which ubiquitinates them for proteasomal degradation. Their ubiquitination and turnover require the presence of ANKRD9. CONCLUSION: ANKRD9, a previously unidentified E3 substrate receptor subunit, functions in tumor suppression by recognizing the oncoprotein IMPDH isoforms for E3 ubiquitination and proteasomal degradation.

Epigenetic silencing of miR-1271 enhances MEK1 and TEAD4 expression in gastric cancer.

Epigenetic dysregulation is a major driver of tumorigenesis. To identify tumor-suppressive microRNAs repressed by DNA methylation in gastric cancer (GC), we analyzed the genome-wide DNA methylation and microRNA expression profiles of EpCAM+/CD44+ GC cells. Among the set of microRNAs screened, miR-1271 was identified as a microRNA repressed by DNA methylation in GC. Forced miR-1271 expression substantially suppressed the growth, migration, and invasion of GC cells. To identify candidate target genes and signaling pathways regulated by miR-1271, we performed RNA sequencing. Among the genes down-regulated by miR-1271, MAP2K1 (MEK1) was significantly repressed by miR-1271, and the associated ERK/MAPK signaling pathway was also inhibited. TEAD4 was also repressed by miR-1271, and the associated YAP1 signatures within genes regulated by miR-1271 were significantly enriched. These findings uncovered MEK1 and TEAD4 as novel miR-1271 targets and suggest that the epigenetic silencing of miR-1271 is crucial for GC development.

Intrinsic Molecular Processes: Impact on Mutagenesis.

Mutations provide resources for genome evolution by generating genetic variability. In addition, mutations act as a driving force leading to disease pathogenesis, and thus have important implications for disease diagnosis, prognosis, and treatment. Understanding the mechanisms underlying how mutations occur is therefore of prime importance for elucidating evolutionary and pathogenic processes. Recent genomics studies have revealed that mutations occur non-randomly across the human genome. In particular, the distribution of mutations is highly associated with intrinsic molecular processes including transcription, chromatin organization, DNA replication timing, and DNA repair. Interplay between intrinsic processes and extrinsic mutagenic exposure may thus imprint a characteristic mutational landscape on tumors. We discuss the impact of intrinsic molecular processes on mutation acquisition in cancer.

Variability in Chromatin Architecture and Associated DNA Repair at Genomic Positions Containing Somatic Mutations.

Dynamic chromatin structures result in differential chemical reactivity to mutational processes throughout the genome. To identify chromatin features responsible for mutagenesis, we compared chromatin architecture around single-nucleotide variants (SNV), insertion/deletions (indels), and their context-matched, nonmutated positions. We found epigenetic differences between genomic regions containing missense SNVs and those containing frameshift indels across multiple cancer types. Levels of active histone marks were higher around frameshift indels than around missense SNV, whereas repressive histone marks exhibited the reverse trend. Accumulation of repressive histone marks and nucleosomes distinguished mutated positions (both SNV and indels) from the context-matched, nonmutated positions, whereas active marks were associated with substitution- and cancer type-specific mutagenesis. We also explained mutagenesis based on genome maintenance mechanisms, including nucleotide excision repair (NER), mismatch repair (MMR), and DNA polymerase epsilon (POLE). Regional NER variation correlated strongly with chromatin features; NER machineries exhibited shifted or depleted binding around SNV, resulting in decreased NER at mutation positions, especially at sites of recurrent mutations. MMR-deficient tumors selectively acquired SNV in regions with high active histone marks, especially H3K36me3, whereas POLE-deficient tumors selectively acquired indels and SNV in regions with low active histone marks. These findings demonstrate the importance of fine-scaled chromatin structures and associated DNA repair mechanisms in mutagenesis. Cancer Res; 77(11); 2822-33. ©2017 AACR.

A proteogenomic approach for protein-level evidence of genomic variants in cancer cells.

Variations in protein coding sequence may sometimes play important roles in cancer development. However, since variants may not express into proteins due to various cellular quality control systems, it is important to get protein-level evidence of the genomic variations. We present a proteogenomic strategy getting protein-level evidence of genomic variants, which we call sequential targeted LC-MS/MS based on prediction of peptide pI and Retention time (STaLPIR). Our approach shows improved peptide identification, and has the potential for the unbiased analysis of variant sequence as well as corresponding reference sequence. Integrated analysis of DNA, mRNA and protein suggests that protein expression level of the nonsynonymous variant is regulated either before or after translation, according to influence of the variant on protein function. In conclusion, our data provides an excellent approach getting direct evidence for the expression of variant protein forms from genome sequence data.

Genomic and epigenomic heterogeneity in molecular subtypes of gastric cancer.

Gastric cancer is a complex disease that is affected by multiple genetic and environmental factors. For the precise diagnosis and effective treatment of gastric cancer, the heterogeneity of the disease must be simplified; one way to achieve this is by dividing the disease into subgroups. Toward this effort, recent advances in high-throughput sequencing technology have revealed four molecular subtypes of gastric cancer, which are classified as Epstein-Barr virus-positive, microsatellite instability, genomically stable, and chromosomal instability subtypes. We anticipate that this molecular subtyping will help to extend our knowledge for basic research purposes and will be valuable for clinical use. Here, we review the genomic and epigenomic heterogeneity of the four molecular subtypes of gastric cancer. We also describe a mutational meta-analysis and a reanalysis of DNA methylation that were performed using previously reported gastric cancer datasets.

Genetic alterations and their clinical implications in gastric cancer peritoneal carcinomatosis revealed by whole-exome sequencing of malignant ascites.

Peritoneal carcinomatosis accompanied by malignant ascites is a major cause of death of advanced gastric cancer (GC). To comprehensively characterize the underlying genomic events involved in GC peritoneal carcinomatosis, we analyzed whole-exome sequences of normal gastric tissues, primary tumors, and malignant ascites from eight GC patients. We identified a unique mutational signature biased toward C-to-A substitutions in malignant ascites. In contrast, the patients who received treatment of adjuvant chemotherapy showed a high rate of C-to-T substitutions along with hypermutation in malignant ascites. Comparative analysis revealed several candidate mutations for GC peritoneal carcinomatosis: recurrent mutations in COL4A6, INTS2, and PTPN13; mutations in druggable genes including TEP1, PRKCD, BRAF, ERBB4, PIK3CA, HDAC9, FYN, FASN, BIRC2, FLT3, ROCK1, CD22, and PIK3C2B; and mutations in metastasis-associated genes including TNFSF12, L1CAM, DIAPH3, ROCK1, TGFBR1, MYO9B, NR4A1, and RHOA. Notably, gene ontology analysis revealed the significant enrichment of mutations in the Rho-ROCK signaling pathway-associated biological processes in malignant ascites. At least four of the eight patients acquired somatic mutations in the Rho-ROCK pathway components, suggesting the possible relevance of this pathway to GC peritoneal carcinomatosis. These results provide a genome-wide molecular understanding of GC peritoneal carcinomatosis and its clinical implications, thereby facilitating the development of effective therapeutics.

Decrease of 5hmC in gastric cancers is associated with TET1 silencing due to with DNA methylation and bivalent histone marks at TET1 CpG island 3'-shore.

Recent evidence has shown that the level of 5-hydroxymethylcytosine (5 hmC) in chromosomal DNA is aberrantly decreased in a variety of cancers, but whether this decrease is a cause or a consequence of tumorigenesis is unclear. Here we show that, in gastric cancers, the 5 hmC decrease correlates with a decrease in ten-eleven translocation 1 (TET1) expression, which is strongly associated with metastasis and poor survival in patients with gastric cancer. In gastric cancer cells, TET1-targeted siRNA induced a decrease in 5 hmC, whereas TET1 overexpression induced an increase in 5 hmC and reduced cell proliferation, thus correlating decreased 5 hmC with gastric carcinogenesis. We also report the epigenetic signatures responsible for regulating TET1 transcription. Methyl-CpG Binding Domain Sequencing and Reduced Representation Bisulfite Sequencing identified unique CpG methylation signatures at the CpG island 3'-shore region located 1.3 kb from the transcription start site of TET1 in gastric tumor cells but not in normal mucosa. The luciferase activity of constructs with a methylated 3'-shore sequence was greatly decreased compared with that of an unmethylated sequence in transformed gastric cancer cells. In gastric cancer cells, dense CpG methylation in the 3'-shore was strongly associated with TET1 silencing and bivalent histone marks. Thus, a decrease in 5 hmC may be a cause of gastric tumorigenesis owing to a decrease in TET1 expression through DNA methylation coupled with bivalent marks in the 3'-shore of TET1.

Genome-wide mutation profiles of colorectal tumors and associated liver metastases at the exome and transcriptome levels.

To characterize the mutation profiles of colorectal cancer (CRC) primary tumors (PTs) and liver metastases (CLMs), we performed both whole-exome and RNA sequencing. Ten significantly mutated genes, including BMI1, CARD11, and NRG1, were found in 34 CRCs with CLMs. We defined three mutation classes (Class 1 to 3) based on the absence or presence of mutations during liver metastasis. Most mutations were classified into Class 1 (shared between PTs and CLMs), suggesting the common clonal origin of PTs and CLMs. Class 1 was more strongly associated with the clinical characteristics of advanced cancer and was more frequently superimposed with chromosomal deletions in CLMs than Class 2 (PT-specific). The integration of exome and RNA sequencing revealed that variant-allele frequencies (VAFs) of mutations in the transcriptome tended to have stronger functional implications than those in the exome. For instance, VAFs of the TP53 and APC mutations in the transcriptome significantly correlated with the expression level of their target genes. Additionally, mutations with high functional impact were enriched with high VAFs in the CLM transcriptomes. We identified 11 mutation-associated splicing events in the CRC transcriptomes. Thus, the integration of the exome and the transcriptome may elucidate the underlying molecular events responsible for CLMs.

Fe3O4 nanosphere@microporous organic networks: enhanced anode performances in lithium ion batteries through carbonization.

Very thin microporous organic networks were formed on the surface of Fe3O4 nanospheres by Sonogashira coupling of tetra(4-ethynylphenyl)methane and 1,4-diiodobenzene. The thickness was controlled by screening the number of building blocks. Through carbonization, Fe3O4@C composites were prepared. The Fe3O4@C composites with 4-6 nm carbon thickness showed promising reversible discharge capacities of up to 807 mA h g(-1) and enhanced electrochemical stability.

Integrative genomics analysis reveals the multilevel dysregulation and oncogenic characteristics of TEAD4 in gastric cancer.

Tumorigenesis is a consequence of failures of multistep defense mechanisms against deleterious perturbations that occur at the genomic, epigenomic, transcriptomic and proteomic levels. To uncover previously unrecognized genes that undergo multilevel perturbations in gastric cancer (GC), we integrated epigenomic and transcriptomic approaches using two recently developed tools: MENT and GENT. This integrative analysis revealed that nine Hippo pathway-related genes, including components [FAT, JUB, LATS2, TEA domain family member 4 (TEAD4) and Yes-associated protein 1 (YAP1)] and targets (CRIM1, CYR61, CTGF and ITGB2), are concurrently hypomethylated at promoter CpG sites and overexpressed in GC tissues. In particular, TEAD4, a link between Hippo pathway components and targets, was significantly hypomethylated at CpG site cg21637033 (P = 3.8 × 10(-) (20)) and overexpressed (P = 5.2 × 10(-) (10)) in 108 Korean GC tissues compared with the normal counterparts. A reduced level of methylation at the TEAD4 promoter was significantly associated with poor outcomes, including large tumor size, high-grade tumors and low survival rates. Compared with normal tissues, the TEAD4 protein was more frequently found in the nuclei of tumor cells along with YAP1 in 53 GC patients, demonstrating the posttranslational activation of this protein. Moreover, the knockdown of TEAD4 resulted in the reduced growth of GC cells both in vitro and in vivo. Finally, chromatin immunoprecipitation-sequencing and microarray analysis revealed the oncogenic properties of TEAD4 and its novel targets (ADM, ANG, ARID5B, CALD1, EDN2, FSCN1 and OSR2), which are involved in cell proliferation and migration. In conclusion, the multilevel perturbations of TEAD4 at epigenetic, transcriptional and posttranslational levels may contribute to GC development.

Comparison of manual rasping and robotic milling for short metaphyseal-fitting stem implantation in total hip arthroplasty: a cadaveric study.

OBJECTIVE: The ROBODOC system offers the theoretical advantage of providing better fit and mechanical stability of the stem in total hip arthroplasty. However, there has been no previous study on short metaphyseal-fitting stem implantation using the ROBODOC system. The aim of the present study was to compare the implant position and primary stability of short metaphyseal-fitting stems implanted by robotic milling and manual rasping in a human cadaveric femoral model. METHODS: Eight matched pairs of human cadaveric femora were randomly assigned to a robotic milling group or manual rasping group. Operative time and intraoperative femoral fractures were monitored, and radiographic evaluation of stem alignment was performed by comparison of preoperative planning and postoperative CT data. Stability testing was performed on six matched pairs of femora, excluding two specimens in which intraoperative fractures occurred. RESULTS: The robotic milling procedures took an average of 27 minutes longer than the manual rasping procedures (p < 0.001). The robotic milling group exhibited significantly better anteroposterior alignment and vertical seating, and also showed a significantly reduced variability in both alignment and vertical seating. No intraoperative femoral fracture was detected in the robotic milling group, whereas two femoral fractures and one femoral stem tip perforation were detected in the manual rasping group. Stability testing showed no significant difference in translational and rotational migrations between the two groups, although the robotic milling group showed a trend towards reduced variability of stability. CONCLUSIONS: Our cadaveric study suggests that the use of the ROBODOC system for short metaphyseal-fitting stem implantation may have advantages in improving implant fit and reducing the risk of intraoperative femoral fractures without compromising primary stability.