Long non-coding RNAs (lncRNAs) regulate a wide array of cellular processes through interactions with RNA-binding proteins (RBPs). Taurine Upregulated Gene 1 (TUG1) is a lncRNA that is overexpressed in many types of cancer and has been implicated in resolving R-loops, thereby maintaining genomic integrity. However, the full spectrum of its protein interactions and stress-responsive dynamics remains unclear.
View Article and Find Full Text PDFCell migration plays a critical role in biological processes such as embryonic development, wound healing, cancer metastasis, and immune response. While the molecular mechanisms regulating cell movement are well-studied, bridging the gap between these mechanisms and macroscopic cell behaviour remains a significant challenge due to the disparity in scale. At the subcellular level, an intermediate scale between molecular and cellular scales, cell membranes exhibit complex structural dynamics that are difficult to quantify and poorly understood.
View Article and Find Full Text PDFIn cancer cells, folate is metabolised in the cytoplasm and mitochondria. Folate metabolism mediates nucleic acid synthesis and, thereby, the growth of cancer cells. One of the enzymes within this folate metabolic pathway, methylenetetrahydrofolate dehydrogenase/cyclohydrolase 2 (MTHFD2), is rarely expressed in normal adult cells but is abundantly expressed in the mitochondria and nuclei of foetal and cancer cells in humans and mice.
View Article and Find Full Text PDFThe regenerative functions associated with cytokines and growth factors have immense therapeutic potential; however, their poor pharmacokinetics, resulting from structural features, hinder their effectiveness. In this study, we aimed to enhance the pharmacokinetics of growth factors by designing receptor-binding macrocyclic peptides through mRNA display and grafting them into loops of immunoglobulin's crystallizable region (Fc). As a model, we developed peptide-grafted Fc proteins with hepatocyte growth factor (HGF) functionality that exhibited a prolonged circulation half-life and could be administered subcutaneously.
View Article and Find Full Text PDFOncogene-induced DNA replication stress (RS) and consequent pathogenic R-loop formation are known to impede S phase progression. Nonetheless, cancer cells continuously proliferate under such high-stressed conditions through incompletely understood mechanisms. Here, we report taurine upregulated gene 1 (TUG1) long noncoding RNA (lncRNA), which is highly expressed in many types of cancers, as an important regulator of intrinsic R-loop in cancer cells.
View Article and Find Full Text PDFBiochem Biophys Res Commun
September 2023
Biochem Biophys Res Commun
December 2021
Patients with triple-negative breast cancer have a poor prognosis as only a few efficient targeted therapies are available. Cancer cells are characterized by their unregulated proliferation and require large amounts of nucleotides to replicate their DNA. One-carbon metabolism contributes to purine and pyrimidine nucleotide synthesis by supplying one carbon atom.
View Article and Find Full Text PDFAlthough it is held that proinflammatory changes precede the onset of breast cancer, the underlying mechanisms remain obscure. Here, we demonstrate that FRS2β, an adaptor protein expressed in a small subset of epithelial cells, triggers the proinflammatory changes that induce stroma in premalignant mammary tissues and is responsible for the disease onset. FRS2β deficiency in mouse mammary tumor virus (MMTV)-ErbB2 mice markedly attenuated tumorigenesis.
View Article and Find Full Text PDFAccumulating evidence indicates the presence of cytoplasmic DNAs in various types of malignant cells, and its involvement in anti-cancer drug- or radiotherapy-mediated DNA damage response and replication stress. However, the pathophysiological roles of cytoplasmic DNAs in leukemias remain largely unknown. We observed that during hematopoietic stem cell transplantation (HSCT) in mouse myeloid leukemia models, double-stranded (ds)DNAs were constitutively secreted in the form of extracellular vesicles (EVs) from myeloid leukemia cells and were transferred to the donor cells to dampen their hematopoietic capabilities.
View Article and Find Full Text PDFMetastatic progression remains the major cause of death in human breast cancer. Cancer cells with cancer stem cell (CSC) properties drive initiation and growth of metastases at distant sites. We have previously established the breast cancer patient-derived tumor xenograft (PDX) mouse model in which CSC marker CD44 cancer cells formed spontaneous microscopic metastases in the liver.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2019
Cancer stem-like cells (CSCs) are expanded in the CSC niche by increased frequency of symmetric cell divisions at the expense of asymmetric cell divisions. The symmetric division of CSCs is important for the malignant properties of cancer; however, underlying molecular mechanisms remain largely elusive. Here, we show a cytokine, semaphorin 3 (Sema3), produced from the CSC niche, induces symmetric divisions of CSCs to expand the CSC population.
View Article and Find Full Text PDFTumor recurrence is attributable to cancer stem-like cells (CSCs), the metabolic mechanisms of which currently remain obscure. Here, we uncovered the critical role of folate-mediated one-carbon (1C) metabolism involving mitochondrial methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) and its downstream purine synthesis pathway. MTHFD2 knockdown greatly reduced tumorigenesis and stem-like properties, which were associated with purine nucleotide deficiency, and caused marked accumulation of 5-aminoimidazole carboxamide ribonucleotide (AICAR)-the final intermediate of the purine synthesis pathway.
View Article and Find Full Text PDFMacrophages in lungs can be classified into two subpopulations, alveolar macrophages (AMs) and interstitial macrophages (IMs), which reside in the alveolar and interstitial spaces, respectively. Accumulating evidence indicates the involvement of IMs in lung metastasis, but the roles of AMs in lung metastasis still remain elusive. An i.
View Article and Find Full Text PDFThe CD74-Neuregulin1 (NRG1) fusion gene was recently identified as novel driver of invasive mucinous adenocarcinoma, a malignant form of lung cancer. However, the function of the CD74-NRG1 fusion gene in adenocarcinoma pathogenesis and the mechanisms by which it may impart protumorigenic characteristics to cancer stem cells (CSC) is still unclear. In this study, we found that the expression of the CD74-NRG1 fusion gene increased the population of lung cancer cells with CSC-like properties.
View Article and Find Full Text PDFThe M2 isoform of pyruvate kinase, the final rate-limiting enzyme of aerobic glycolysis, is expressed during embryonic development. In contrast, the M1 isoform is expressed in differentiated cells due to alternative splicing. Here we investigated murine embryonic stem cells (ESCs) with or knock-in alleles.
View Article and Find Full Text PDFBackground: Glioblastoma multiforme (GBM) is one of the most aggressive human tumors, and the establishment of an effective therapeutic reagent is a pressing priority. Recently, it has been shown that the tumor tissue consists of heterogeneous components and that a highly aggressive population should be the therapeutic target.
Methods: Through a single subcutaneous passage of GBM cell lines LN443 and U373 in mice, we have developed highly aggressive variants of these cells named LN443X, U373X1, and U373X2, which showed increased tumor growth, colony-forming potential, sphere-forming potential, and invasion ability.
Biochem Biophys Res Commun
March 2013