Publications by authors named "Keiichi Nakayama"

Cancer cells adeptly manipulate the tumor microenvironment (TME) to evade host antitumor immunity. However, the role of cancer cell-intrinsic signaling in shaping the immunosuppressive TME remains unclear. Here, we found that the Hippo pathway in cancer cells orchestrates the TME by influencing the composition of cancer-associated fibroblasts (CAFs).

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The mammalian p57 protein is a member of the CIP/KIP family of cyclin-dependent kinase inhibitors and plays an essential role in the development of multiple tissues during embryogenesis as well as in the maintenance of tissue stem cells in adults. Although several transcription factors have been implicated in regulating the p57 gene, cis-elements such as enhancers that regulate its expression have remained ill-defined. Here we identify a candidate enhancer for the mouse p57 gene (Cdkn1c) within an intron of the Kcnq1 locus by 4C-seq analysis in mouse embryonic stem cells (mESCs).

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c-Myc is a proto-oncoprotein that regulates various cellular processes and whose abnormal expression leads to tumorigenesis. c-Myc protein stability has been shown to be predominantly controlled by the ubiquitin ligase (E3) CRL1 in a manner dependent on glycogen synthase kinase 3 (GSK3)-mediated phosphorylation. Here we show that, in some types of cancer cells, c-Myc degradation is largely insensitive to the GSK3 inhibitor (GSK3i) CHIR99021, suggesting the existence of an E3 other than CRL1 for c-Myc degradation.

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Background: Recently, two molecular subtypes of pancreatic ductal adenocarcinoma (PDAC) have been proposed: the "Classical" and "Basal-like" subtypes, with the former showing better clinical outcomes than the latter. However, the "molecular" classification has not been applied in real-world clinical practice. This study aimed to establish patient-derived organoids (PDOs) for PDAC and evaluate their application in subtype classification and clinical outcome prediction.

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Mitochondrial transcription factor A, TFAM, is essential for mitochondrial function. We examined the effects of overexpressing the gene in mice. Two types of transgenic mice were created: heterozygous ( Tg) and homozygous ( Tg/Tg) mice.

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Article Synopsis
  • - Increased lactate levels from glycolysis are being studied as potential markers for metabolic changes in neurons, linked to a drop in brain pH, which has been associated with various neuropsychiatric disorders like schizophrenia and autism.
  • - Research shows that these pH and lactate changes are common across different animal models, including those for depression, epilepsy, and Alzheimer's disease, though findings vary, particularly within the autism spectrum.
  • - A large-scale analysis indicated that higher lactate levels correlate with worse working memory performance, suggesting that altered brain chemistry might reflect underlying conditions across multiple disorders.
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CHD8 is an ATP-dependent chromatin-remodeling factor encoded by the most frequently mutated gene in individuals with autism spectrum disorder (ASD). Although many studies have examined the consequences of CHD8 haploinsufficiency in cells and mice, few have focused on missense mutations, the most common type of CHD8 alteration in ASD patients. We here characterized CHD8 missense mutations in ASD patients according to six prediction scores and experimentally examined the effects of such mutations on the biochemical activities of CHD8, neural differentiation of embryonic stem cells, and mouse behavior.

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Cancer stem cells (CSCs) are a long-lived and self-renewing cancer cell population that drives tumor propagation and maintains cancer heterogeneity. They are also implicated in the therapeutic resistance of various types of cancer. Recent studies of CSCs in colorectal cancer (CRC) have uncovered fundamental paradigms that have increased understanding of CSC systems in solid tumors.

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Major depressive disorder (depression) is a leading cause of disability. The severity of depression is affected by many factors, one of which being comorbidity with diabetes mellitus (DM). The comorbidity of depression with DM is a major public health concern due to the high incidence of both conditions and their mutually exacerbating pathophysiology.

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Nicotinamide phosphoribosyltransferase (NAMPT) plays a major role in NAD biosynthesis in many cancers and is an attractive potential cancer target. However, factors dictating therapeutic efficacy of NAMPT inhibitors (NAMPTi) are unclear. We report that neuroendocrine phenotypes predict lung and prostate carcinoma vulnerability to NAMPTi, and that NAMPTi therapy against those cancers is enhanced by dietary modification.

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Ribosomes polymerize nascent peptides through repeated inter-subunit rearrangements between the classic and hybrid states. The peptidyl-tRNA, the intermediate species during translation elongation, stabilizes the translating ribosome to ensure robust continuity of elongation. However, the translation of acidic residue-rich sequences destabilizes the ribosome, leading to a stochastic premature translation cessation termed intrinsic ribosome destabilization (IRD), which is still ill-defined.

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C-C chemokine receptor type 2 (CCR2) is the receptor for C-C motif chemokine 2 (CCL2) and is associated with various inflammatory diseases and cancer metastasis. Although many inhibitors for CCR2 have been developed, it remains unresolved which inhibitors are the most effective in the clinical setting. In the present study, we compared 10 existing human CCR2 antagonists in a calcium influx assay using human monocytic leukemia cells.

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Each tissue has a dominant set of functional proteins required to mediate tissue-specific functions. Epigenetic modifications, transcription, and translational efficiency control tissue-dominant protein production. However, the coordination of these regulatory mechanisms to achieve such tissue-specific protein production remains unclear.

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Developing CD4CD8 double-positive (DP) thymocytes with randomly generated T cell receptors (TCRs) undergo positive (maturation) or negative (apoptosis) selection on the basis of the strength of TCR stimulation. Selection fate is determined by engagement of TCR ligands with a subtle difference in affinity, but the molecular details of TCR signaling leading to the different selection outcomes have remained unclear. We performed phosphoproteome analysis of DP thymocytes and found that p90 ribosomal protein kinase (RSK) phosphorylation at Thr was induced specifically by high-affinity peptide ligands.

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Article Synopsis
  • * A study identified that hypoxanthine phosphoribosyltransferase 1 (HPRT1) helps SCLC cells survive in low-glutamine environments, indicating its role in cancer progression.
  • * Combining HPRT1 inhibition with other drugs targeting purine synthesis pathways showed significant tumor suppression in mouse models, suggesting a promising new therapeutic strategy for SCLC.
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Nonalcoholic fatty liver disease (NAFLD) is a chronic metabolic disorder caused by overnutrition and can lead to nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). The transcription factor Forkhead box K1 (FOXK1) is implicated in regulation of lipid metabolism downstream of mechanistic target of rapamycin complex 1 (mTORC1), but its role in NAFLD-NASH pathogenesis is understudied. Here, we show that FOXK1 mediates nutrient-dependent suppression of lipid catabolism in the liver.

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Reactive oxygen species (ROS) posed a risk for the transition of vertebrates from aquatic to terrestrial life. How ancestral organisms adapted to such ROS exposure has remained a mystery. Here, we show that attenuation of the activity of the ubiquitin ligase CRL3Keap1 for the transcription factor Nrf2 during evolution was key to development of an efficient response to ROS exposure.

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Translation initiates when the eIF4F complex binds the 5' mRNA cap, followed by 5' untranslated region scanning for the start codon by scanning ribosomes. Here, we demonstrate that the ASC-1 complex (ASCC), which was previously shown to promote the dissociation of colliding 80S ribosomes, associates with scanning ribosomes to regulate translation initiation. Selective translation complex profiling (TCP-seq) analysis revealed that ASCC3, a helicase domain-containing subunit of ASCC, localizes predominantly to the 5' untranslated region of mRNAs.

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Although several ribosomal protein paralogs are expressed in a tissue-specific manner, how these proteins affect translation and why they are required only in certain tissues have remained unclear. Here we show that RPL3L, a paralog of RPL3 specifically expressed in heart and skeletal muscle, influences translation elongation dynamics. Deficiency of RPL3L-containing ribosomes in RPL3L knockout male mice resulted in impaired cardiac contractility.

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Background: Driver alterations may represent novel candidates for driver gene-guided therapy; however, intrahepatic cholangiocarcinoma (ICC) with multiple genomic aberrations makes them intractable. Therefore, the pathogenesis and metabolic changes of ICC need to be understood to develop new treatment strategies. We aimed to unravel the evolution of ICC and identify ICC-specific metabolic characteristics to investigate the metabolic pathway associated with ICC development using multiregional sampling to encompass the intra- and inter-tumoral heterogeneity.

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Unlabelled: Quiescent cancer stem cells (CSC) are resistant to conventional anticancer treatments and have been shown to contribute to disease relapse after therapy in some cancer types. The identification and characterization of quiescent CSCs could facilitate the development of strategies to target this cell population and block recurrence. Here, we established a syngeneic orthotopic transplantation model in mice based on intestinal cancer organoids to profile quiescent CSCs.

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A cyclin-dependent kinase (CDK) inhibitor, p57Kip2, is an important molecule involved in bone development; p57Kip2-deficient (p57-/-) mice display neonatal lethality resulting from abnormal bone formation and cleft palate. The modulator 1α,25-dihydroxyvitamin D3 (l,25-(OH)2VD3) has shown the potential to suppress the proliferation and induce the differentiation of normal and tumor cells. The current study assessed the role of p57Kip2 in the 1,25-(OH)2VD3-regulated differentiation of osteoblasts because p57Kip2 is associated with the vitamin D receptor (VDR).

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Adult neurogenesis is supported by multipotent neural stem cells (NSCs) with unique properties and growth requirements. Adult NSCs constitute a reversibly quiescent cell population that can be activated by extracellular signals from the microenvironment in which they reside in vivo. Although genomic imprinting plays a role in adult neurogenesis through dose regulation of some relevant signals, the roles of many imprinted genes in the process remain elusive.

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Mechanistic target of rapamycin complex 1 (mTORC1) is a serine-threonine kinase that is activated by extracellular signals, such as nutrients and growth factors. It plays a key role in the control of various biological processes, such as protein synthesis and energy metabolism by mediating or regulating the phosphorylation of multiple target molecules, some of which remain to be identified. We have here reanalysed a large-scale phosphoproteomics data set for mTORC1 target molecules and identified pre-B cell leukemia transcription factor 2 (PBX2) as such a novel target that is dephosphorylated downstream of mTORC1.

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Article Synopsis
  • LIGHTHOUSE is a new deep learning tool that simplifies the process of identifying potential drugs by analyzing how small molecules interact with target proteins without needing detailed structural info.
  • It has successfully identified treatments for various diseases, including cancer and infections, and notably predicted ethoxzolamide as a potential COVID-19 therapeutic.
  • The goal of LIGHTHOUSE is to streamline drug discovery, making it easier and faster to translate research findings into effective treatments for patients.
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