Publications by authors named "Kiyotsugu Yoshida"

The Hedgehog (Hh) signaling pathway is critical for regulating cell growth, survival, fate determination, and the overall patterning of both vertebrate and invertebrate body plans. Aberrations in Hh signaling are associated with congenital abnormalities and tumorigenesis. In vertebrates, Hh signaling depends uniquely on primary cilia, microtubule-based organelles that extend from the cell surface.

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The functional maturation of the pituitary gland requires adequate cell differentiation and vascular network formation. Although spatiotemporal signaling and transcription factors are known to govern pituitary development, the involvement of primary cilia, nonmoving hair-like organelles, remains unclear. In this study, we uncovered the contribution of primary cilia to cell-type determination and vascular network formation during pituitary development.

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Hedgehog (Hh) signaling, an evolutionarily conserved pathway, plays an essential role in development and tumorigenesis, making it a promising drug target. Multiple negative regulators are known to govern Hh signaling; however, how activated Smoothened (SMO) participates in the activation of downstream GLI2 and GLI3 remains unclear. Herein, we identified the ciliary kinase DYRK2 as a positive regulator of the GLI2 and GLI3 transcription factors for Hh signaling.

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To maintain microenvironmental and cellular homeostasis, cells respond to multiple stresses by activating characteristic cellular mechanisms consisting of receptors, signal transducers, and effectors. Dysfunction of these mechanisms can trigger multiple human diseases as well as cancers. Dual-specificity tyrosine-regulated kinases (DYRKs) are members of the CMGC group and are evolutionarily conserved from yeast to mammals.

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Objectives: Lung cancer is a leading cause of cancer-related mortality and remains one of the most poorly prognosed disease worldwide. Therefore, it is necessary to identify novel molecular markers with potential therapeutic effects. Recent findings have suggested that dual-specificity tyrosine-regulated kinase 2 (DYRK2) plays a tumor suppressive role in colorectal, breast, and hepatic cancers; however, its effect and mechanism in lung cancer remain poorly understood.

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Invariant natural killer T (iNKT) cells are innate-like T lymphocytes that express an invariant T cell receptor α chain and contribute to bridging innate and acquired immunity with rapid production of large amounts of cytokines after stimulation. Among effecter subsets of iNKT cells, follicular helper NKT (NKT) cells are specialized to help B cells. However, the mechanisms of NKT cell differentiation remain to be elucidated.

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Article Synopsis
  • The study highlights the limitations of traditional liver cancer markers, α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP), particularly in early-stage hepatocellular carcinoma (HCC) and in patients with liver issues.
  • Researchers evaluated serum protein kinase C delta (PKCδ) as a potential new biomarker for HCC diagnosis and found it to have high sensitivity and specificity, even in early stages of the disease.
  • PKCδ levels remained consistent regardless of hepatitis C virus (HCV) status, liver injury, or warfarin treatment, making it a promising alternative to conventional markers for more accurate HCC detection.
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The dual-specificity tyrosine phosphorylation-regulated kinase 2 (DYRK2) regulates the induction of apoptosis and DNA repair, metastasis inhibition, cell cycle G1/S transition, protein scaffold stability for E3 ligase complexes, and embryogenesis. Owing to these functions, DYRK2 is thought to regulate tumorigenesis, and its function in cancer has been investigated. Notably, DYRK2 has been reported to function as a tumor suppressor; however, it has also been reported to act as an oncogene in some cancers.

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Dual-specificity tyrosine-regulated kinase 2 (DYRK2) is a protein kinase that phosphorylates p53-Ser46 and induces apoptosis in response to DNA damage. However, the relationship between DYRK2 expression and chemosensitivity after DNA damage in colorectal cancer has not been well investigated. The aim of the present study was to examine whether DYRK2 could be a novel marker for predicting chemosensitivity after 5-fluorouracil- and oxaliplatin-induced DNA damage in colorectal cancer.

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Background & Aims: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and has a poor prognosis. However, the molecular mechanisms underlying hepatocarcinogenesis and progression remain unknown. gain- and loss-of-function analyses in cell lines and xenografts revealed that dual-specificity tyrosine-regulated kinase 2 (DYRK2) influences tumour growth in HCC.

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Extended-synaptotagmin 1 (E-Syt1) is an endoplasmic reticulum membrane protein that is involved in cellular lipid transport. Our previous study identified E-Syt1 as a key factor for the unconventional protein secretion of cytoplasmic proteins in liver cancer, such as protein kinase C delta (PKCδ); however, it is unclear whether E-Syt1 is involved in tumorigenesis. Here, we showed that E-Syt1 contributes to the tumorigenic potential of liver cancer cells.

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Unconventional protein secretion (UPS) is a crucial mechanism controlling the localization of cytosolic proteins lacking signal peptides and is implicated in inflammation, neurodegenerative diseases, and cancer. Several previous studies on immune cells have demonstrated the mechanisms of UPS. In cancer, the active secretion of several cytosolic proteins, including PKCδ and nucleolin, has been described.

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Protein kinase C delta (PKCδ) is a multifunctional serine-threonine kinase implicated in cell proliferation, differentiation, tumorigenesis, and therapeutic resistance. However, the molecular mechanism of PKCδ in colorectal cancer (CRC) remains unclear. In this study, we showed that PKCδ acts as a negative regulator of cellular senescence in p53 wild-type (wt-p53) CRC.

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Protein secretion in cancer cells defines tumor survival and progression by orchestrating the microenvironment. Studies suggest the occurrence of active secretion of cytosolic proteins in liver cancer and their involvement in tumorigenesis. Here, we investigated the identification of extended-synaptotagmin 1 (E-Syt1), an endoplasmic reticulum (ER)-bound protein, as a key mediator for cytosolic protein secretion at the ER-plasma membrane (PM) contact sites.

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Backgrounds And Aims: Hepatocellular carcinoma (HCC) is the most common cancer with a poor prognosis. Identification of an alternative biomarker that can detect early-stage and conventional tumor marker-negative HCC is urgently needed. We found that protein kinase C delta (PKCδ) is specifically secreted from HCC cell lines into extracellular space and contributes to tumor development and that its serum levels were elevated in HCC patients.

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Neural precursor cell-expressed developmentally down-regulated 8 (NEDD8), an ubiquitin-like protein, is an essential regulator of the DNA damage response. Numerous studies have shown that neddylation (conjugation of NEDD8 to target proteins) dysfunction causes several human diseases, such as cancer. Hence clarifying the regulatory mechanism of neddylation could provide insight into the mechanism of genome stability underlying the DNA damage response (DDR) and carcinogenesis.

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Protein kinase C delta (PKCδ) is a multifunctional PKC family member and has been implicated in many types of cancers, including liver cancer. Recently, we have reported that PKCδ is secreted from liver cancer cells, and involved in cell proliferation and tumor growth. However, it remains unclear whether the extracellular PKCδ directly regulates cell surface growth factor receptors.

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Protein kinase Cδ (PKCδ) is a member of the PKC family, and its implications have been reported in various biological and cancerous processes, including cell proliferation, cell death, tumor suppression, and tumor progression. In liver cancer cells, accumulating reports show the bi-functional regulation of PKCδ in cell death and survival. PKCδ function is defined by various factors, such as phosphorylation, catalytic domain cleavage, and subcellular localization.

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The dual-specificity tyrosine-regulated kinase (DYRK) family is evolutionarily conserved from invertebrate to mammals. DYRKs regulate cell proliferation, apoptosis, survival, and differentiation by modifying the protein activation state, cellular localization, and turnover. In contrast to several studies in cellular models, the available evidence regarding the roles of DYRKs in mammalian development is limited.

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Colorectal cancer is one of the most common gastrointestinal tumors with good outcomes; however, with distant metastasis, the outcomes are poor. Novel treatment methods are urgently needed. Our in vitro studies indicate that dual-specificity tyrosine-regulated kinase 2 (DYRK2) functions as a tumor suppressor in colorectal cancer by regulating cell survival, proliferation, and apoptosis induction.

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Congenital malformations cause life-threatening diseases in pediatrics, yet the molecular mechanism of organogenesis is poorly understood. Here we show that Dyrk2-deficient mice display congenital malformations in multiple organs. Transcriptome analysis reveals molecular pathology of Dyrk2-deficient mice, particularly with respect to Foxf1 reduction.

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Protein kinase C-delta (PKCδ) has a caspase-3 recognition sequence in its structure, suggesting its involvement in apoptosis. In addition, PKCδ was recently reported to function as an anti-cancer factor. The generation of a PKCδ knockout mouse model indicated that PKCδ plays a role in B cell homeostasis.

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Article Synopsis
  • In 2008, guidelines were established for researching autophagy, which has since gained significant interest and new technologies, necessitating regular updates to monitoring methods across various organisms.
  • The new guidelines emphasize selecting appropriate techniques to evaluate autophagy while noting that no single method suits all situations; thus, a combination of methods is encouraged.
  • The document highlights that key proteins involved in autophagy also impact other cellular processes, suggesting genetic studies should focus on multiple autophagy-related genes to fully understand these pathways.
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Metastatic progression is the leading cause of mortality in breast cancer. However, molecular mechanisms that govern this process remain unclear. In this study, we found that carbonic anhydrase 13 (CA13) plays a potential role in suppressing bone metastasis.

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