83 research outputs found
Sequence Evidence in the Archaeal Genomes that tRNAs Emerged Through the Combination of Ancestral Genes as 5′ and 3′ tRNA Halves
The discovery of separate 5′ and 3′ halves of transfer RNA (tRNA) molecules—so-called split tRNA—in the archaeal parasite Nanoarchaeum equitans made us wonder whether ancestral tRNA was encoded on 1 or 2 genes. We performed a comprehensive phylogenetic analysis of tRNAs in 45 archaeal species to explore the relationship between the three types of tRNAs (nonintronic, intronic and split). We classified 1953 mature tRNA sequences into 22 clusters. All split tRNAs have shown phylogenetic relationships with other tRNAs possessing the same anticodon. We also mimicked split tRNA by artificially separating the tRNA sequences of 7 primitive archaeal species at the anticodon and analyzed the sequence similarity and diversity of the 5′ and 3′ tRNA halves. Network analysis revealed specific characteristics of and topological differences between the 5′ and 3′ tRNA halves: the 5′ half sequences were categorized into 6 distinct groups with a sequence similarity of >80%, while the 3′ half sequences were categorized into 9 groups with a higher sequence similarity of >88%, suggesting different evolutionary backgrounds of the 2 halves. Furthermore, the combinations of 5′ and 3′ halves corresponded with the variation of amino acids in the codon table. We found not only universally conserved combinations of 5′–3′ tRNA halves in tRNAiMet, tRNAThr, tRNAIle, tRNAGly, tRNAGln, tRNAGlu, tRNAAsp, tRNALys, tRNAArg and tRNALeu but also phylum-specific combinations in tRNAPro, tRNAAla, and tRNATrp. Our results support the idea that tRNA emerged through the combination of separate genes and explain the sequence diversity that arose during archaeal tRNA evolution
Correlation between fabrication factor and superconducting properties of the Tl-and-Bi-based high-Tc superconductor
Large critical current densities (J(sub c)) were obtained in c axis oriented Tl-1 223/Ag composite tapes fabricated by spraying methods without a vacuum. Transport measurements at 77K under a zero field indicated a J(sub c) of 9 x 10(exp 4) A/sq cm and 7 x 10(exp 3) A/sq cm at 1T for the tapes fabricated by spray pyrolysis. The novel GPM method was also applied for Bi-2212/Ag PIT composite wire, and found to be very effective for improving the distribution of voids, which caused from the melt-solidifying process. The GPM showed a marked effect for obtaining homogeneous long wire. A 1 T class coil was successfully fabricated with monocore wire
Capstone Design Hub: Building the Capstone Design Community
Capstone design courses are common across engineering programs nationwide. Yet, many departments and programs rely on one faculty member or a small handful of faculty members to teach their capstone design course. As a result these faculty members find themselves isolated, with limited mechanisms for sharing ideas and networking with peers who have similar responsibilities and concerns. This paper reports on the ongoing efforts to support the broader capstone design community through the development of the Capstone Design Hub (CDHub) as a web resource for capstone design programs. The features and structure of the CDHub are being developed through capstone faculty input, including results from a survey of the capstone community. To build awareness of the CDHub as well as to solicit additional feedback from the community, this paper describes development of the hub to meet community needs, initial population of the hub with resources focused on communication, and plans for continued expansion of the hub. © 2012 American Society for Engineering Education
Inter-assay variability of next-generation sequencing-based gene panels
BACKGROUND: Tumor heterogeneity has been known to cause inter-assay discordance among next-generation sequencing (NGS) results. However, whether preclinical factors such as sample type, sample quality and analytical features of gene panel can affect the concordance between two different assays remains largely unexplored. METHODS: Replicate sets of DNA samples extracted from formalin-fixed paraffin-embedded tissues (FFPE) (n = 20) and fresh frozen (FF) tissues (n = 10) were herein analyzed using a tumor-only (TO) and paired tumor-normal (TN) gene panel in laboratories certified by the Clinical Laboratory Improvement Amendment. Reported variants from the TO and TN panels were then compared. Furthermore, additional FFPE samples were sequentially sliced from the same FFPE block and submitted to another TN panel assay. RESULTS: Substantial discordance (71.8%) was observed between the results of the two panels despite using identical DNA samples, with the discordance rate being significantly higher for FFPE samples (p < 0.05). Among the 99 variants reported only in the TO panel, 32.3% were consistent with germline variants, which were excluded in the TN panel, while 30.3% had an allele frequency of less than 5%, some of which were highly likely to be artificial calls. The comparison of two independent TN panel assay results from the same FFPE block also showed substantial discordance rate (55.3%). CONCLUSIONS: In the context of clinical settings, our comparative analysis revealed that inter-NGS assay discordance commonly occurred due to sample types and the different analytical features of each panel
Genomic Heterogeneity in a Natural Archaeal Population Suggests a Model of tRNA Gene Disruption
Combination treatment with highly bioavailable curcumin and NQO1 inhibitor exhibits potent antitumor effects on esophageal squamous cell carcinoma
Background: Esophageal squamous cell carcinoma (ESCC) is one of the most intractable cancers, so the development of novel therapeutics has been required to improve patient outcomes. Curcumin, a polyphenol from Curcuma longa, exhibits various health benefits including antitumor effects, but its clinical utility is limited because of low bioavailability. Theracurmin® (THC) is a highly bioavailable curcumin dispersed with colloidal submicron particles. Methods: We examined antitumor effects of THC on ESCC cells by cell viability assay, colony and spheroid formation assay, and xenograft models. To reveal its mechanisms, we investigated the levels of reactive oxygen species (ROS) and performed microarray gene expression analysis. According to those analyses, we focused on NQO1, which involved in the removal of ROS, and examined the effects of NQO1-knockdown or overexpression on THC treatment. Moreover, the therapeutic effect of THC and NQO1 inhibitor on ESCC patient-derived xenografts (PDX) was investigated. Results: THC caused cytotoxicity in ESCC cells, and suppressed the growth of xenografted tumors more efficiently than curcumin. THC increased ROS levels and activated the NRF2–NMRAL2P–NQO1 expressions. Inhibition of NQO1 in ESCC cells by shRNA or NQO1 inhibitor resulted in an increased sensitivity of cells to THC, whereas overexpression of NQO1 antagonized it. Notably, NQO1 inhibitor significantly enhanced the antitumor effects of THC in ESCC PDX tumors. Conclusions: These findings suggest the potential usefulness of THC and its combination with NQO1 inhibitor as a therapeutic option for ESCC
HER2 G776S mutation promotes oncogenic potential in colorectal cancer cells when accompanied by loss of APC function
Clinical cancer genome sequencing detects oncogenic variants that are potential targets for cancer treatment, but it also detects variants of unknown significance. These variants may interact with each other to influence tumor pathophysiology, however, such interactions have not been fully elucidated. Additionally, the effect of target therapy for those variants also unclarified. In this study, we investigated the biological functions of a HER2 mutation (G776S mutation) of unknown pathological significance, which was detected together with APC mutation by cancer genome sequencing of samples from a colorectal cancer (CRC) patient. Transfection of the HER2 G776S mutation alone slightly increased the kinase activity and phosphorylation of HER2 protein, but did not activate HER2 downstream signaling or alter the cell phenotype. On the other hand, the HER2 G776S mutation was shown to have strong oncogenic potential when loss of APC function was accompanied. We revealed that loss of APC function increased Wnt pathway activity but also increased RAS-GTP, which increased ERK phosphorylation triggered by HER2 G776S transfection. In addition, afatinib, a pan-HER tyrosine kinase inhibitor, suppressed tumor growth in xenografts derived from HER2 G776S-transfected CRC cells. These findings suggest that this HER2 mutation in CRC may be a potential therapeutic target
Evidence for Ongoing Modeling-Based Bone Formation in Human Femoral Head Trabeculae via Forming Minimodeling Structures: A Study in Patients with Fractures and Arthritis.
Bone modeling is a biological process of bone formation that adapts bone size and shape to mechanical loads, especially during childhood and adolescence. Bone modeling in cortical bone can be easily detected using sequential radiographic images, while its assessment in trabecular bone is challenging. Here, we performed histomorphometric analysis in 21 bone specimens from biopsies collected during hip arthroplasty, and we proposed the criteria for histologically identifying an active modeling-based bone formation, which we call a "forming minimodeling structure" (FMiS). Evidence of FMiSs was found in 9 of 20 specimens (45%). In histomorphometric analysis, bone volume was significant higher in specimens displaying FMiSs compared with the specimens without these structures (BV/TV, 31.7 ± 10.2 vs. 23.1 ± 3.9%; p < 0.05). Osteoid parameters were raised in FMiS-containing bone specimens (OV/BV, 2.1 ± 1.6 vs. 0.6 ± 0.3%; p < 0.001, OS/BS, 23.6 ± 15.5 vs. 7.6 ± 4.2%; p < 0.001, and O.Th, 7.4 µm ± 2.0 vs. 5.2 ± 1.0; p < 0.05). Our results showed that the modeling-based bone formation on trabecular bone surfaces occurs even during adulthood. As FMiSs can represent histological evidence of modeling-based bone formation, understanding of this physiology in relation to bone homeostasis is crucial
Comprehensive genomic profiling for patients with chemotherapy‐naïve advanced cancer
Comprehensive genomic profiling (CGP) testing by next-generation sequencing has been introduced into clinical practice as part of precision cancer medicine to select effective targeted therapies. However, whether CGP testing at the time of first-line chemotherapy could be clinically useful is not clear. We conducted this single-center, prospective, observational study to investigate the feasibility of CGP testing for chemotherapy-naïve patients with stage III/IV gastrointestinal cancer, rare cancer, and cancer of unknown primary, using the FoundationOne® companion diagnostic (F1CDx) assay. The primary outcome was the detection rate of at least one actionable/druggable cancer genomic alteration. Actionable/druggable cancer genomic alterations were determined by the F1CDx report. An institutional molecular tumor board determined the molecular-based recommended therapies. A total of 197 patients were enrolled from October 2018 to June 2019. CGP success rate was 76.6% (151 of 197 patients), and median turnaround time was 19 days (range: 10-329 days). Actionable and druggable cancer genomic alterations were reported in 145 (73.6%) and 124 (62.9%) patients, respectively. The highest detection rate of druggable genomic alterations in gastrointestinal cancers was 80% in colorectal cancer (48 of 60 patients). Molecular-based recommended therapies were determined in 46 patients (23.4%). CGP testing would be a useful tool for the identification of a potentially effective first-line chemotherapy
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