Functionally conserved enhancers with divergent sequences in distant vertebrates

Conserved transcription factor binding motifs in the five zebrafish/mouse syntenic enhancers. Identical n-mers (n ≥ 7) identified in the zebrafish, mouse, and human sequences of the five syntenic CNS were examined for the presence of transcription factor binding motifs; only motifs with E-value E ≤ 0.1 are shown. (XLSX 15 kb

Genome methylation in D. melanogaster is found at specific short motifs and is independent of DNMT2 activity

Cytosine methylation in the genome of Drosophila melanogaster has been elusive and controversial: Its location and function have not been established. We have used a novel and highly sensitive genomewide cytosine methylation assay to detect and map genome methylation in stage 5 Drosophila embryos. The methylation we observe with this method is highly localized and strand asymmetrical, limited to regions covering ∼1% of the genome, dynamic in early embryogenesis, and concentrated in specific 5-base sequence motifs that are CA- and CT-rich but depleted of guanine. Gene body methylation is associated with lower expression, and many genes containing methylated regions have developmental or transcriptional functions. The only known DNA methyltransferase in Drosophila is the DNMT2 homolog MT2, but lines deficient for MT2 retain genomic methylation, implying the presence of a novel methyltransferase. The association of methylation with a lower expression of specific developmental genes at stage 5 raises the possibility that it participates in controlling gene expression during the maternal-zygotic transition

Silencing of p53 and CDKN1A establishes sustainable immortalized megakaryocyte progenitor cells from human iPSCs

iPS細胞を用いた人工血小板の作製の効率化に成功 血小板のテイラーメイド医療に向けた一歩. 京都大学プレスリリース. 2021-12-03.Platelet transfusions are critical for severe thrombocytopenia but depend on blood donors. The shortage of donors and the potential of universal HLA-null platelet products have stimulated research on the ex vivo differentiation of human pluripotent stem cells (hPSCs) to platelets. We recently established expandable immortalized megakaryocyte cell lines (imMKCLs) from hPSCs by transducing MYC, BMI1, and BCL-XL (MBX). imMKCLs can act as cryopreservable master cells to supply platelet concentrates. However, the proliferation rates of the imMKCLs vary with the starting hPSC clone. In this study, we reveal from the gene expression profiles of several MKCL clones that the proliferation arrest is correlated with the expression levels of specific cyclin-dependent kinase inhibitors. Silencing CDKN1A and p53 with the overexpression of MBX was effective at stably inducing imMKCLs that generate functional platelets irrespective of the hPSC clone. Collectively, this improvement in generating imMKCLs should contribute to platelet industrialization and platelet biology

Transient IGF-1R inhibition combined with osimertinib eradicates AXL-low expressing EGFR mutated lung cancer

Drug tolerance is the basis for acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) including osimertinib, through mechanisms that still remain unclear. Here, we show that while AXL-low expressing EGFR mutated lung cancer (EGFRmut-LC) cells are more sensitive to osimertinib than AXL-high expressing EGFRmut-LC cells, a small population emerge osimertinib tolerance. The tolerance is mediated by the increased expression and phosphorylation of insulin-like growth factor-1 receptor (IGF-1R), caused by the induction of its transcription factor FOXA1. IGF-1R maintains association with EGFR and adaptor proteins, including Gab1 and IRS1, in the presence of osimertinib and restores the survival signal. In AXL-low-expressing EGFRmut-LC cell-derived xenograft and patient-derived xenograft models, transient IGF-1R inhibition combined with continuous osimertinib treatment could eradicate tumors and prevent regrowth even after the cessation of osimertinib. These results indicate that optimal inhibition of tolerant signals combined with osimertinib may dramatically improve the outcome of EGFRmut-LC

Brain natriuretic peptide and cancer

Background Natriuretic peptides have been proposed as biomarkers of cardiovascular disease, especially heart failure. Brain natriuretic peptide (BNP) has also been shown to be upregulated at the transcriptional and translational levels by pro-inflammatory cytokines in cardiac myocytes. Although we often measure plasma BNP levels in cancer patients, it remains unknown whether cancer-related inflammation affects the plasma BNP levels. We investigated the relationship between the BNP and human cancers. Methods We retrospectively studied 2,923 patients in whom the plasma BNP levels and serum C-reactive protein (CRP) were measured and echocardiography was performed. Patients with clinically evident heart failure (NYHA II or higher), heart disease requiring medical treatment or surgery, renal dysfunction, and inflammatory disease were excluded. There were 234 patients in the final analysis. Blood sampling was performed before surgery and chemotherapy. In addition, we evaluated the relationship between the inflammation and plasma BNP levels in mouse models of colon cancer. Results Of the 234 patients, 80 were diagnosed with cancer. Both the plasma BNP and serum CRP levels were significantly higher in cancer patients than those without. There were no significant differences in the echocardiographic parameters. There was a significant positive correlation between the plasma BNP and serum CRP levels in cancer patients (r = 0.360, P<0.01) but not in those without. In cancer patients, only the CRP correlated with the BNP independent of the age, creatinine level, hypertension, and body mass index. In addition, in nude mice with subcutaneous colon cancer, the plasma BNP level was elevated compared with that in non-cancer mice, and there was a significant relationship between the plasma BNP and serum levels of the inflammatory markers. Conclusions In cancer patients, as well as colon cancer model mice, the plasma BNP levels were elevated, possibly due to cancer-related inflammation. The effect of cancer on the BNP levels should be considered when using BNP as an indicator of heart failure in cancer patients

Endosomal escape and the knockdown efficiency of liposomal-siRNA by the fusogenic peptide shGALA

An siRNA that specifically silences the expression of mRNA is a potential therapeutic agent for dealing with many diseases including cancer. However, the poor cellular uptake and bioavailability of siRNA remains a major obstacle to clinical development. For efficient delivery to tumor tissue, the pharmacokinetics and intracellular trafficking of siRNA must be rigorously controlled. To address this issue, we developed a liposomal siRNA carrier, a multi-functional nano device (MEND). We describe herein an approach for systemic siRNA delivery to tumors by combining the MEND system with shGALA, a fusogenic peptide. In cultured cell experiments, shGALA-modification enhanced the endosomal escape of siRNA encapsulated in a polyethylene glycol modified MEND (PEG-MEND), resulting in an 82% knockdown of the target gene. In vivo systemic administration clarified that the shGALA-modified MEND (shGALA-MEND) showed 58% gene silencing in tumor tissues at a dose of 4 mg of siRNA/kg body weight. In addition, a significant inhibition of tumor growth was observed only for the shGALA-MEND and no somatic or hepatic toxicity was observed. Given the above data, this peptide-modified delivery system, a shGALA-MEND has great potential for the systemic delivery of therapeutic siRNA aimed at cancer therapy

GINS, a novel multiprotein complex required for chromosomal DNA replication in budding yeast

Eukaryotic chromosomal DNA replication requires a two-step assembly of replication proteins on origins; formation of the prereplicative complex (pre-RC) in late M and G1 phases of the cell cycle, and assembly of other replication proteins in S phase to load DNA polymerases to initiate DNA synthesis. In budding yeast, assembly of Dpb11 and the Sld3–Cdc45 complex on the pre-RC at origins is required for loading DNA polymerases. Here we describe a novel replication complex, GINS (Go, Ichi, Nii, and San; five, one, two, and three in Japanese), in budding yeast, consisting of Sld5, Psf1 (partner of Sld five 1), Psf2, and Psf3 proteins, all of which are highly conserved in eukaryotic cells. Since the conditional mutations of Sld5 and Psf1 confer defect of DNA replication under nonpermissive conditions, GINS is suggested to function for chromosomal DNA replication. Consistently, in S phase, GINS associates first with replication origins and then with neighboring sequences. Without GINS, neither Dpb11 nor Cdc45 associates properly with chromatin DNA. Conversely, without Dpb11 or Sld3, GINS does not associate with origins. Moreover, genetic and two-hybrid interactions suggest that GINS interacts with Sld3 and Dpb11. Therefore, Dpb11, Sld3, Cdc45, and GINS assemble in a mutually dependent manner on replication origins to initiate DNA synthesis

Usefulness of a Kampo Medicine on Stress-Induced Delayed Gastric Emptying in Mice

Anxiety and depression often occur with gastrointestinal symptoms. Although the Japanese traditional medicine (Kampo medicine) bukuryoingohangekobokuto (BGH) is approved for treating anxiety, neurotic gastritis, and heartburn, its effect on gastrointestinal motility remains poorly known. This study aimed to examine the effect of BGH on delayed gastric emptying in stress model mice and clarified its action mechanism. Seven-week-old C57BL/6 male mice were acclimated for a week and fasted overnight. Stress hormone, corticotropin-releasing factor (CRF), was intracerebroventricularly injected to mice, and solid nutrient meal (ground chow and distilled water) was orally administered 1 hour after. Gastric contents were collected to evaluate gastric emptying rates by measuring its dry weight. Injection of CRF (0.3 or 1.0 μg/mouse) significantly delayed the 2-hour gastric emptying in mice. BGH (1.0 g/kg), which was administered 30 minutes before the CRF injection, significantly ameliorated the delayed gastric emptying induced by CRF (0.3 μg/mouse). BGH (0.5, 1.0 g/kg) significantly enhanced the 1-hour gastric emptying and slightly increased the 2-hour gastric emptying in mice without CRF injection. In vitro functional assays showed that components of BGH antagonized or inhibited CRF type-2, dopamine D2/D3, neuropeptide Y Y2 receptors, or acetylcholinesterase. In conclusion, the components of BGH may exert synergistic effects on improving gastric emptying via various targets. BGH is considered to be potentially useful for treating gastrointestinal dysmotility with psychological symptoms