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Cell Division Jun 2024This review aims to outline mitotic kinase inhibitors' roles as potential therapeutic targets and assess their suitability as a stand-alone clinical therapy or in... (Review)
Review
This review aims to outline mitotic kinase inhibitors' roles as potential therapeutic targets and assess their suitability as a stand-alone clinical therapy or in combination with standard treatments for advanced-stage solid tumors, including triple-negative breast cancer (TNBC). Breast cancer poses a significant global health risk, with TNBC standing out as the most aggressive subtype. Comprehending the role of mitosis is crucial for understanding how TNBC advances from a solid tumor to metastasis. Chemotherapy is the primary treatment used to treat TNBC. Some types of chemotherapeutic agents target cells in mitosis, thus highlighting the need to comprehend the molecular mechanisms governing mitosis in cancer. This understanding is essential for devising targeted therapies to disrupt these mitotic processes, prevent or treat metastasis, and improve patient outcomes. Mitotic kinases like Aurora kinase A, Aurora Kinase B, never in mitosis gene A-related kinase 2, Threonine-Tyrosine kinase, and Polo-kinase 1 significantly impact cell cycle progression by contributing to chromosome separation and centrosome homeostasis. When these kinases go awry, they can trigger chromosome instability, increase cell proliferation, and activate different molecular pathways that culminate in a transition from epithelial to mesenchymal cells. Ongoing clinical trials investigate various mitotic kinase inhibitors as potential biological treatments against advanced solid tumors. While clinical trials against mitotic kinases have shown some promise in the clinic, more investigation is necessary, since they induce severe adverse effects, particularly affecting the hematopoietic system.
PubMed: 38886738
DOI: 10.1186/s13008-024-00125-x -
Yi Chuan = Hereditas Jun 2024Ssu72 is a component of the yeast cleavage/polyadenylation factor (CPF) complex, which catalyzes the dephosphorylation of the C-terminal domain (CTD) of RNA polymerase...
Ssu72 is a component of the yeast cleavage/polyadenylation factor (CPF) complex, which catalyzes the dephosphorylation of the C-terminal domain (CTD) of RNA polymerase II at S5-P and S7-P. It has been shown that Ssu72 phosphatase is involved in regulating chromosome cohesion during mitosis. To further clarify whether Ssu72 phosphatase affects chromosome separation during meiotic division in , we utilized green fluorescent protein (GFP) to label centromeres and red fluorescent protein to label microtubule protein Atb2. The entire meiotic chromosome separation process of cells was observed in real-time under fluorescence microscope. It was found that two spindles of cells crossed during the metaphase and anaphase of the second meiotic division, and this spindle crossing led to a new type of spore defect distribution pattern. The results of this study can provide important reference significance for studying the roles of phosphatase Ssu72 in higher organisms.
Topics: Meiosis; Schizosaccharomyces; Spindle Apparatus; Schizosaccharomyces pombe Proteins; Chromosome Segregation
PubMed: 38886153
DOI: 10.16288/j.yczz.24-047 -
Research Square Jun 2024A deep learning model using attention-based multiple instance learning (aMIL) and self-supervised learning (SSL) was developed to perform pathologic classification of...
A deep learning model using attention-based multiple instance learning (aMIL) and self-supervised learning (SSL) was developed to perform pathologic classification of neuroblastic tumors and assess -amplification status using H&E-stained whole slide digital images. The model demonstrated strong performance in identifying diagnostic category, grade, mitosis-karyorrhexis index (MKI), and -amplification on an external test dataset. This AI-based approach establishes a valuable tool for automating diagnosis and precise classification of neuroblastoma tumors.
PubMed: 38883758
DOI: 10.21203/rs.3.rs-4396782/v1 -
Scientific Reports Jun 2024Receptor Expression-Enhancing Protein 3 (REEP3) serves as a pivotal enzyme crucial for endoplasmic reticulum (ER) clearance during mitosis and is implicated in the...
Receptor Expression-Enhancing Protein 3 (REEP3) serves as a pivotal enzyme crucial for endoplasmic reticulum (ER) clearance during mitosis and is implicated in the advancement of diverse malignancies. Nonetheless, the biological role and mechanisms of REEP3 in pancreatic cancer patients, along with its interplay with immune infiltration, remain inadequately elucidated. In this study, we initially analyzed the differential expression of REEP3 between pancreatic cancer tissues and normal pancreas tissues using the Cancer Genome Atlas (TCGA), GTEx and Gene Expression Omnibus (GEO) databases. Subsequently, we utilized Kaplan-Meier analysis, Cox regression and ROC curve to determine the predictive value of REEP3 for the clinical outcomes of pancreatic cancer patients. Functional enrichment analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA), were conducted to explore the potential signaling pathways and biological functions associated with pancreatic cancer. Furthermore, we investigated the PPI network, miRNA, RBP and transcription factor interactions of REEP3 using databases such as GeneMania, STRING, StarBase, KnockTK, ENCODE, Jaspar and hTFtarget. Lastly, the "ssGSEA" algorithm and TIMER database were employed to investigate the correlation between REEP3 expression and immune infiltration as well as immune checkpoints. The expression of REEP3 in pancreatic cancer showed a significantly higher level compared to that in normal tissues. ROC curve analysis indicated that REEP3 holds substantial diagnostic potential for pancreatic cancer patients. Elevated REEP3 expression correlated with unfavorable outcomes in terms of both overall survival and relapse-free survival, establishing it as a notable adverse prognostic marker in pancreatic cancer. Moreover, both univariate and multivariate Cox regression analyses demonstrated that REEP3 maintained an independent association with overall survival. Functional enrichment analyses revealed pathways significantly linked to REEP3, including cytoplasmic translation, wound healing, viral processes, regulation of cellular component size and actin filament organization. Additionally, REEP3 expression displayed a significant positive correlation with CD8+ T cells, B cells, natural killer cells, dendritic cells and macrophages. REEP3 is a potential diagnostic, prognostic marker and immunotherapeutic target for pancreatic cancer.
Topics: Female; Humans; Male; Middle Aged; Biomarkers, Tumor; Gene Expression Regulation, Neoplastic; Kaplan-Meier Estimate; Lymphocytes, Tumor-Infiltrating; Pancreatic Neoplasms; Prognosis; Protein Interaction Maps; ROC Curve
PubMed: 38879709
DOI: 10.1038/s41598-024-64720-2 -
ESMO Open Jun 2024Six thoracic pathologists reviewed 259 lung neuroendocrine tumours (LNETs) from the lungNENomics project, with 171 of them having associated survival data. This cohort...
BACKGROUND
Six thoracic pathologists reviewed 259 lung neuroendocrine tumours (LNETs) from the lungNENomics project, with 171 of them having associated survival data. This cohort presents a unique opportunity to assess the strengths and limitations of current World Health Organization (WHO) classification criteria and to evaluate the utility of emerging markers.
PATIENTS AND METHODS
Patients were diagnosed based on the 2021 WHO criteria, with atypical carcinoids (ACs) defined by the presence of focal necrosis and/or 2-10 mitoses per 2 mm. We investigated two markers of tumour proliferation: the Ki-67 index and phospho-histone H3 (PHH3) protein expression, quantified by pathologists and automatically via deep learning. Additionally, an unsupervised deep learning algorithm was trained to uncover previously unnoticed morphological features with diagnostic value.
RESULTS
The accuracy in distinguishing typical from ACs is hampered by interobserver variability in mitotic counting and the limitations of morphological criteria in identifying aggressive cases. Our study reveals that different Ki-67 cut-offs can categorise LNETs similarly to current WHO criteria. Counting mitoses in PHH3+ areas does not improve diagnosis, while providing a similar prognostic value to the current criteria. With the advantage of being time efficient, automated assessment of these markers leads to similar conclusions. Lastly, state-of-the-art deep learning modelling does not uncover undisclosed morphological features with diagnostic value.
CONCLUSIONS
This study suggests that the mitotic criteria can be complemented by manual or automated assessment of Ki-67 or PHH3 protein expression, but these markers do not significantly improve the prognostic value of the current classification, as the AC group remains highly unspecific for aggressive cases. Therefore, we may have exhausted the potential of morphological features in classifying and prognosticating LNETs. Our study suggests that it might be time to shift the research focus towards investigating molecular markers that could contribute to a more clinically relevant morpho-molecular classification.
Topics: Humans; Lung Neoplasms; Neuroendocrine Tumors; Female; Ki-67 Antigen; Male; Biomarkers, Tumor; Middle Aged; World Health Organization; Histones; Aged; Prognosis; Deep Learning
PubMed: 38878324
DOI: 10.1016/j.esmoop.2024.103591 -
EMBO Reports Jun 2024Junctions between the endoplasmic reticulum (ER) and the outer membrane of the nuclear envelope (NE) physically connect both organelles. These ER-NE junctions are...
Junctions between the endoplasmic reticulum (ER) and the outer membrane of the nuclear envelope (NE) physically connect both organelles. These ER-NE junctions are essential for supplying the NE with lipids and proteins synthesized in the ER. However, little is known about the structure of these ER-NE junctions. Here, we systematically study the ultrastructure of ER-NE junctions in cryo-fixed mammalian cells staged in anaphase, telophase, and interphase by correlating live cell imaging with three-dimensional electron microscopy. Our results show that ER-NE junctions in interphase cells have a pronounced hourglass shape with a constricted neck of 7-20 nm width. This morphology is significantly distinct from that of junctions within the ER network, and their morphology emerges as early as telophase. The highly constricted ER-NE junctions are seen in several mammalian cell types, but not in budding yeast. We speculate that the unique and highly constricted ER-NE junctions are regulated via novel mechanisms that contribute to ER-to-NE lipid and protein traffic in higher eukaryotes.
PubMed: 38877171
DOI: 10.1038/s44319-024-00175-w -
Scientific Reports Jun 2024In filamentous fungi, microtubules are important for polar growth and morphological maintenance and serve as rails for intracellular trafficking. The molecular...
In filamentous fungi, microtubules are important for polar growth and morphological maintenance and serve as rails for intracellular trafficking. The molecular mechanisms associated with microtubules have been analyzed. However, little is known about when and where tubulin, a component of microtubules, is biosynthesized in multinuclear and multicellular filamentous fungi. In this study, we visualized microtubules based on the enhanced green fluorescence protein (EGFP)-labeled α-tubulin and β-tubulin mRNA tagged by the EGFP-mediated MS2 system in living yellow Koji mold Aspergillus oryzae cells in order to understand the spatiotemporal production mechanism of tubulin. We found that mRNA of btuA, encoding for β-tubulin, localized at dot-like structures through the apical, middle and basal regions of the hyphal cells. In addition, some btuA mRNA dots showed microtubule-dependent motor protein-like dynamics in the cells. Furthermore, it was found that btuA mRNA dots were decreased in the cytoplasm just before mitosis but increased immediately after mitosis, followed by a gradual decrease. In summary, the localization and abundance of β-tubulin mRNA is spatiotemporally regulated in living A. oryzae hyphal cells.
Topics: Aspergillus oryzae; Tubulin; RNA, Messenger; Microtubules; Hyphae; Green Fluorescent Proteins; Gene Expression Regulation, Fungal; Fungal Proteins
PubMed: 38877139
DOI: 10.1038/s41598-024-64531-5 -
Proceedings of the National Academy of... Jun 2024Error correction is central to many biological systems and is critical for protein function and cell health. During mitosis, error correction is required for the...
Error correction is central to many biological systems and is critical for protein function and cell health. During mitosis, error correction is required for the faithful inheritance of genetic material. When functioning properly, the mitotic spindle segregates an equal number of chromosomes to daughter cells with high fidelity. Over the course of spindle assembly, many initially erroneous attachments between kinetochores and microtubules are fixed through the process of error correction. Despite the importance of chromosome segregation errors in cancer and other diseases, there is a lack of methods to characterize the dynamics of error correction and how it can go wrong. Here, we present an experimental method and analysis framework to quantify chromosome segregation error correction in human tissue culture cells with live cell confocal imaging, timed premature anaphase, and automated counting of kinetochores after cell division. We find that errors decrease exponentially over time during spindle assembly. A coarse-grained model, in which errors are corrected in a chromosome-autonomous manner at a constant rate, can quantitatively explain both the measured error correction dynamics and the distribution of anaphase onset times. We further validated our model using perturbations that destabilized microtubules and changed the initial configuration of chromosomal attachments. Taken together, this work provides a quantitative framework for understanding the dynamics of mitotic error correction.
Topics: Humans; Chromosome Segregation; Kinetochores; Mitosis; Spindle Apparatus; Microtubules; Anaphase; Models, Biological; HeLa Cells
PubMed: 38875144
DOI: 10.1073/pnas.2323009121 -
Renal Failure Dec 2024Podocyte loss in glomeruli is a fundamental event in the pathogenesis of chronic kidney diseases. Currently, mitotic catastrophe (MC) has emerged as the main cause of...
Podocyte loss in glomeruli is a fundamental event in the pathogenesis of chronic kidney diseases. Currently, mitotic catastrophe (MC) has emerged as the main cause of podocyte loss. However, the regulation of MC in podocytes has yet to be elucidated. The current work aimed to study the role and mechanism of p53 in regulating the MC of podocytes using adriamycin (ADR)-induced nephropathy. podocyte stimulation with ADR triggered the occurrence of MC, which was accompanied by hyperactivation of p53 and cyclin-dependent kinase (CDK1)/cyclin B1. The inhibition of p53 reversed ADR-evoked MC in podocytes and protected against podocyte injury and loss. Further investigation showed that p53 mediated the activation of CDK1/cyclin B1 by regulating the expression of Wee1. Restraining Wee1 abolished the regulatory effect of p53 inhibition on CDK1/cyclin B1 and rebooted MC in ADR-stimulated podocytes p53 inhibition. In a mouse model of ADR nephropathy, the inhibition of p53 ameliorated proteinuria and podocyte injury. Moreover, the inhibition of p53 blocked the progression of MC in podocytes in ADR nephropathy mice through the regulation of the Wee1/CDK1/cyclin B1 axis. Our findings confirm that p53 contributes to MC in podocytes through regulation of the Wee1/CDK1/Cyclin B1 axis, which may represent a novel mechanism underlying podocyte injury and loss during the progression of chronic kidney disorder.
Topics: Podocytes; Animals; CDC2 Protein Kinase; Tumor Suppressor Protein p53; Mice; Protein-Tyrosine Kinases; Doxorubicin; Cyclin B1; Cell Cycle Proteins; Mitosis; Disease Models, Animal; Humans; Male
PubMed: 38874119
DOI: 10.1080/0886022X.2024.2365408 -
Cancer Letters Jun 2024Lysosomes are single membrane bounded group of acidic organelles that can be involved in a process called lysosomal exocytosis which leads to the extracellular release... (Review)
Review
Lysosomes are single membrane bounded group of acidic organelles that can be involved in a process called lysosomal exocytosis which leads to the extracellular release of their content. Lysosomal exocytosis is required for plasma membrane repair or remodeling events such as bone resorption, antigen presentation or mitosis, and for protection against toxic agents such as heavy metals. Recently, it has been showed that to fulfill this protective role, lysosomal exocytosis needs some autophagic proteins, in an autophagy-independent manner. In addition to these crucial physiological roles, lysosomal exocytosis plays a major protumoral role in various cancers. This effect is exerted through tumor microenvironment modifications, including extracellular matrix remodeling, acidosis, oncogenic and profibrogenic signals. This review provides a comprehensive overview of the different elements released in the microenvironment during lysosomal exocytosis, i.e. proteases, exosomes, and protons, and their effects in the context of tumor development and treatment.
PubMed: 38871244
DOI: 10.1016/j.canlet.2024.217024