Search Results (671)

Urinary extracellular vesicles (U-EVs) are gaining increasing interest as non-invasive liquid biopsy tools for clinical use. Prostate cancer (PCa) is amongst the highest cancer-related cause of death in men, and therefore, the identification of non-invasive robust biomarkers is of high importance. This study assessed U-EV profiles from individuals affected by PCa at Gleason scores 6–9, compared with healthy controls. U-EVs were characterised and assessed for proteomic cargo content by LC-MS/MS analysis. The U-EV proteomes were compared for enrichment of gene ontology (GO), KEGG, and Reactome pathways, as well as disease–gene associations. U-EVs ranged in size from 50 to 350 nm, with the majority falling within the 100–200 nm size range for all groups. U-EV protein cargoes from the PCa groups differed significantly from healthy controls, with 16 protein hits unique to the GS 6–7 and 88 hits to the GS 8–9 U-EVs. Pathway analysis showed increased enrichment in the PCa U-EVs of biological process GO (5 and 37 unique to GS 6–7 and GS 8–9, respectively), molecular function GO (3 and 6 unique to GS 6–7 and GS 8–9, respectively), and cellular component GO (10 and 22 unique to GS 6–7 and GS 8–9, respectively) pathways. A similar increase was seen for KEGG pathways (11 unique to GS 8–9) and Reactome pathways (102 unique to GS 8–9). Enrichment of disease–gene associations was also increased in the PCa U-EVs, with highest differences for the GS 8–9 U-EVs (26 unique terms). The pathway enrichment in the PCa U-EVs was related to several key inflammatory, cell differentiation, cell adhesion, oestrogen signalling, and infection pathways. Unique GO and KEGG pathways enriched for the GS 8–9 U-EVs were associated with cell–cell communication, immune and stress responses, apoptosis, peptidase activity, antioxidant activity, platelet aggregation, mitosis, proteasome, mRNA stability oxytocin signalling, cardiomyopathy, and several neurodegenerative diseases. Our findings highlight U-EVs as biomarkers to inform disease pathways in prostate cancer patients and offer a non-invasive biomarker tool for clinical use. Full article

Aurora kinase B (AURKB), a serine/threonine protein kinase, is essential for accurate chromosome segregation and cytokinesis during mitosis. Dysregulation of AURKB, often characterized by its overexpression, has been implicated in various malignancies, including breast cancer. However, the mechanisms governing its dysregulation remain incompletely understood. Here, we identify a pivotal role for the MOF/MSL complex—which includes the histone acetyltransferase MOF (KAT8)—in modulating AURKB stability through acetylation at lysine 215 (K215). This post-translational modification inhibits AURKB ubiquitination, thereby stabilizing its protein levels. MOF/MSL-mediated AURKB stabilization promotes the proper assembly of the chromosomal passenger complex (CPC), ensuring mitotic fidelity. Notably, inhibition of MOF reduces AURKB K215 acetylation, leading to decreased AURKB expression and activity. Consequently, this downregulation suppresses expression of the downstream oncogene c-MYC, ultimately attenuating the malignant proliferation of breast cancer cells. Collectively, our findings reveal a novel mechanism by which lysine acetylation regulates AURKB stability, highlight the significance of the MOF-AURKB-c-MYC axis in breast cancer progression, and suggest potential therapeutic strategies targeting this pathway in clinical settings. Full article

Mitotic figures in tumor tissues are an important criterion for diagnosing malignant lesions, and physicians often search for the presence of mitosis in whole slide imaging (WSI). However, prolonged visual inspection by doctors may increase the likelihood of human error. With the advancement of deep learning, AI-based automatic cytopathological diagnosis has been increasingly applied in clinical settings. Nevertheless, existing diagnostic models often suffer from high computational costs and suboptimal detection accuracy. More importantly, when assessing cellular abnormalities, doctors frequently compare target cells with their surrounding cells—an aspect that current models fail to capture due to their lack of intercellular information modeling, leading to the loss of critical medical insights. To address these limitations, we conducted an in-depth analysis of existing models and propose an Inter–Intra Hypergraph Neural Network (II-HGNN). Our model introduces a block-based feature extraction mechanism to efficiently capture deep representations. Additionally, we leverage hypergraph convolutional networks to process both intracellular and intercellular information, leading to more precise diagnostic outcomes. We evaluate our model on publicly available datasets under varying imaging conditions, and experimental results demonstrate that our approach consistently outperforms baseline models in terms of accuracy. Full article

Mesenchymal stem cells (MSCs) have a broad clinical potential, but their selection and expansion on plastic cause unknown purity and phenotypic alterations, reducing therapy efficiency. Furthermore, their behavior in non-adherent conditions during systemic transplantation remains poorly understood. The sphere formation from single cells is commonly used to assess stemness, but MSCs lack this ability, raising questions about their anchorage dependence for proliferation. We investigated whether bone marrow-derived MSCs can complete cytokinesis in non-adherent environments. Primary human and mouse bone marrow-derived MSCs were synchronized in early mitosis using nocodazole and were cultured on soft, rigid, or non-adherent surfaces. Both human and mouse MSCs displayed an ALIX (abscission licensor) recruitment to the midbody 40–90 min post-nocodazole release, regardless of the substrate adherence. Cells maintained for 4hr in the suspension remained viable, and daughter cells rapidly migrated apart upon the re-adhesion to fibronectin-coated surfaces, demonstrating cytokinesis completion in suspension. These findings distinguish MSCs from fibroblasts (which require adhesion for division), provide a more general stemness feature, and suggest that adhesion-independent cytokinesis is a trait relevant to the post-transplantation survival and tissue homing. This property may offer strategies to expand MSCs with an improved purity and functionality and to enhance engraftment by leveraging cell cycle manipulation to promote an early extracellular matrix deposition at target sites. Full article

Spindle orientation (SO) plays a critical role in tissue morphogenesis, homeostasis, and tumorigenesis by ensuring accurate division plane positioning in response to intrinsic and extrinsic cues. While SO has been extensively linked to cell shape sensing and cortical forces, the interplay between shape- and force-sensing mechanisms remains poorly understood. Here, we reveal that SO is governed by two parallel mechanisms that ensure redundancy and adaptability in diverse cellular environments. Using live-cell imaging of cultured cells, we demonstrate that the long prometaphase axis (LPA) is a superior predictor of SO compared to the long interphase axis, reflecting adhesive geometry and force distribution efficiently at prometaphase. Importantly, we uncover a pivotal role for focal adhesion kinase (FAK) in mediating cortical mechanosensing to regulate SO in cells undergoing complete metaphase rounding. We show that in cells with complete metaphase rounding, FAK-dependent force sensing aligns the spindle with the major force vector, ensuring accurate division. Conversely, in cells retaining shape anisotropy during mitosis, a FAK-independent shape-sensing mechanism drives SO. These findings highlight a dual regulatory system for SO, where shape sensing and force sensing operate in parallel to maintain division plane fidelity, shedding light on the mechanisms that enable cells to adapt to diverse physical and mechanical environments. Full article

WEE1 kinase is a crucial cell cycle regulatory protein that controls the timing of mitotic entry. WEE1, via inhibition of Cyclin-dependent Kinase 1 (CDK1) and Cyclin-dependent Kinase 2 (CDK2), governs the G2-M checkpoint by inhibiting entry into mitosis. The state of balance between WEE family kinases and CDC25C phosphatases restricts CDK1/CycB activity. The WEE kinase family consists of WEE1, PKMYT1, and WEE2 (WEE1B). WEE1 and PKMYT1 regulate entry into mitosis during cell cycle progression, whereas WEE2 governs cell cycle progression during meiosis. Recent studies have identified WEE1 as a potential therapeutic target in several cancers, including therapy-resistant triple-negative breast cancer. Adavosertib’s clinical promise was challenged by inter-individual variations in response and side effects. Because of these promising preclinical outcomes, other WEE1 kinase inhibitors (Azenosertib, SC0191, IMP7068, PD0407824, PD0166285, WEE1-IN-5, Zedoresertib, WEE1-IN-8, and ATRN-1051) are being developed, with several currently being evaluated in clinical trials or as an adjuvant to chemotherapies. Preclinical studies show WEE1 inhibitors induce MHC class 1 antigens and STING when given as combination therapies, suggesting potential additional therapeutic opportunities. Reliable predictors of clinical responses based on mechanistic insights remain an important unmet need. Herein, we review the role of WEE1 inhibition therapy in breast cancer. Full article

This study investigates the pathophysiological process of healed perforated corneal ulcers (HPCUs) in humans. All subjects underwent keratoplasty due to opacities or leakage from HPCUs. Half of each specimen was fixed with 4% glutaraldehyde for transmission electron microscope (TEM) examination. The other half was fixed in 10% formaldehyde for immunofluorescence (IF) examination. TEM identified layered structures with two cell types (polygonal and elongated) connected by gap or adherent junctions during early stage of healing. Both apoptotic and mitotic changes were found in both types of cells. There were no endothelial cells or Descemet’s membrane (DM) present in early stage of healing. During the intermediate stage, the healed area comprised three layers: epithelium, Bowman’s layer, and stroma, with an increase in stromal collagen. Later, adjacent endothelial cells crept in, forming DM and completing the cornea’s 5-layer structure. IF examinations revealed that vimentin⁺ and α-smooth muscle actin (αSMA)⁺ myofibroblasts gathered around the damaged site. Proliferating cell nuclear antigen⁺ cells, which indicated cell proliferation, were found in both cells. Anti-phospho-histone H2AX antibodies were found in some epithelial cells. CK14-positive cells were only found in superficial polygonal cells. Corneal wound healing is a complex process that includes apoptosis, cell migration, mitosis, differentiation, and extracellular matrix remodeling. Full article

Studying the cell cycle is essential for understanding the molecular mechanisms that regulate cell division, growth, and differentiation in living organisms. However, mitosis constitutes only a brief phase of the overall cell cycle, making its analysis challenging in asynchronous cell populations due to its transient and dynamic nature. Cell synchronization methods help to enrich populations at specific cell cycle stages, including mitosis, typically by using chemical inhibitors to arrest cells at defined checkpoints. However, many existing protocols rely on combinations of inhibitors that interfere with normal mitotic progression, disrupting dynamics and causing side effects such as chromosome non-disjunction or lagging chromosomes, which limit their applicability. In this study, we present an RO3306 block-and-release strategy to selectively enrich cell populations at defined mitotic stages without compromising cell viability or disrupting their progression to mitotic exit. This approach provides a reliable method for studying mitotic events with high temporal resolution. Furthermore, by preserving mitotic integrity, it offers a valuable framework for investigating the molecular mechanisms of cell division and the processes driving genomic instability in human cells. Full article

In cytogenetics, the ability to perform FISH (Fluorescence In Situ Hybridization) experiments using probes that map very closely together depends on the capacity to produce sufficiently long chromosomes. Traditionally, colcemid is the chemical agent used to obtain metaphase spreads. However, various substances have been reported to arrest cells in an earlier stage of mitosis than the metaphase, potentially providing longer chromosomes. In this study, we tested seven substances different from colcemid, which, according to the literature, have this capability: Vinblastine, Combretastatin A-4, Podophyllotoxin, Org9935, Nocodazole, Paclitaxel, and Griseofulvin. All substances were tested on lymphocyte cultures derived from whole blood at the same concentration: 0.1 µg/mL. Among these, Org9935 and Griseofulvin were confirmed to have the ability to produce metaphases with longer chromosomes compared to those obtained with colcemid. Full article

Human papillomavirus (HPV) 16 is transported in a retrograde fashion from the cell surface to the Golgi apparatus. Prior to mitosis, the virus loses association with the Golgi and, following nuclear envelope breakdown, is found associated with the condensed mitotic chromatin. The intervening steps have not been well defined. It was previously demonstrated that the virus is transported to the mitotic chromosomes in vesicles. Here, we describe the role of the endoplasmic reticulum (ER) in the post-Golgi trafficking and the importance of the ER-generated coat protein complex II (COPII) anterograde trafficking pathway in HPV infection. HPV pseudovirus (PsV) colocalized with COPII components and silencing of this pathway inhibited HPV infection. Additionally, the inner COPII coat protein, Sec24b, could be biochemically isolated in association with HPV capsid proteins. This study provides insight into the mechanism of post-Golgi HPV trafficking. Full article

In this review dedicated to the great protistologist Edouard Chatton (1883–1947), I wanted to highlight the originality and remarkable diversity of some dinoflagellate protists through the lens of cell biology. Their fossilized traces date back to more than 538 million years (Phanerozoic eon). However, they may be much older because acritarchs from the (Meso) Proterozoic era (1500 million years ago) could be their most primitive ancestors. Here, I described several representative examples of the various lifestyles of free-living (the autotrophic thecate Prorocentrum micans Ehrenberg and the heterotrophic athecate Noctiluca scintillans McCartney and other “pseudo-noctilucidae”, as well as the thecate Crypthecodinium cohnii Biecheler) and of parasitic dinoflagellates (the mixotroph Syndinium Chatton). Then, I compared the different dinoflagellate mitotic systems and reported observations on the eyespot (ocelloid), an organelle that is present in the binucleated Glenodinium foliaceum Stein and in some Warnowiidae dinoflagellates and can be considered an evolutionary marker. The diversity and innovations observed in mitosis, meiosis, reproduction, sexuality, cell cycle, locomotion, and nutrition allow us to affirm that dinoflagellates are among the most innovative unicells in the Kingdom Protista. Full article

Pancreatic cancer is a tumor with a poor prognosis, and improving its survival outcomes remains a formidable challenge, requiring a multidisciplinary approach that integrates innovative surgical and pharmacological strategies, guided by molecular and genetic insights. The pathomorphological and genetic characteristics of pancreatic cancer, reflected in morphological, immunohistochemical, and serological marker expression, reveal key patterns of tumor genotypic changes during carcinogenesis, aiding in prognostic evaluation and clinical strategy development. The mutational profile of pancreatic tumors is quite heterogeneous and diverse in terms of mutated genes, including in relation to morphological subtypes, but certain patterns have been identified as a result of studies. Pancreatic adenocarcinoma, for instance, is frequently driven by mutations regulating cell division (KRAS). The disease prognosis often depends on the morphological subtype and tumor microenvironment. Neuroendocrine tumors of the pancreas are characterized by a number of pathogenetic features that distinguish them from adenocarcinomas. Thus, neuroendocrine tumors are characterized by mutations of the MENIN protein, which prevents cells from entering the mitosis phase by stimulating the expression of cell cycle regulators. Thus, epithelial and neuroendocrine malignancies of the pancreas differ in immunohistochemical and genetic features, but there are similar mechanisms of pathogenesis, such as BRCA1 and BRCA2 gene mutations, impaired expression of p53 antioncogene, and HIF-2α and mTOR receptor mutations. The predictive impact of serological markers, such as CA 19-9 and CEA, offers insights into tumor metastasis and long-term outcomes, emphasizing the need for personalized therapeutic strategies. Tailoring treatments based on individual molecular profiles holds promise for improving prognosis, as the genetic landscape of pancreatic tumors varies significantly between patients. This underscores the importance of a systematic, patient-specific approach that addresses tumor heterogeneity, resistance mechanisms, and the molecular underpinnings of carcinogenesis. Full article

Adult neurogenesis in cartilaginous fish remains a relatively unexplored area, particularly in terms of comparative analysis. This process, defined as the ability of specialized stem cells to generate new functional neurons, has gained prominence due to its relevance in neurodegenerative disease research and regenerative medicine. However, there is an ongoing discussion about when and where it first appeared. Evidence of adult neurogenesis in both teleosts and mammals highlights significant differences, such as the number of newly formed cells and the brain regions involved. Investigating additional cartilaginous fish species, which occupy a basal position in vertebrate phylogeny, could provide valuable insights into the ancient origins of this trait and potentially new general knowledge about the adult neurogenesis process. In this study, we combined immunohistochemistry and in situ hybridization to examine neurogenic activity in three brain regions—the telencephalon, mesencephalon, and cerebellum—of two batoid species: Raja asterias and Torpedo ocellata. Immunohistochemical methods were used to identify neurogenic cells by employing markers for cell proliferation (PCNA), mitosis (pH3), glial cells (S100B), and stem cells (Msi1). Additionally, in situ hybridization was performed to detect neural stem cell mRNA for Notch1, Notch3, and Sox2 in the telencephalon and mesencephalon of Raja asterias. Full article

Current research discusses the putative importance of RNA modification in tumor diseases. These RNA modifications include predominantly pseudouridinylation, ortho-methylations on the ribose residues, as well as methylations on the organic bases. Such chemical modifications directly influence fundamental properties such as transcript stability, alternative splicing, and translation efficiency, all of which are basic requirements for (tumor) cell proliferation, cell metabolism, cell migration, apoptosis resistance, etc. In this comparative study, the two RNA-modifying factors, pseudouridine synthase 7 (PUS7, RNA pseudouridinylation) and WT1-associated protein (WTAP, m6A RNA methylation), were identified using data from human renal cell carcinoma (RCC) tumors. PUS7 and WTAP showed a statistically significant correlation with relevant proliferation and prognosis markers such as CXCR4, TP53, PTEN, and NRAS, as well as with the two tumor immune checkpoints HLA-G and LGALS9 and were directly associated with a statistically significant effect on overall survival. Furthermore, comparative analyses also identified further putative target mRNAs of importance for tumor biology of PUS7 and WTAP. In particular, components with direct relevance for mitosis, the cell cycle, and cell division, as well as the WNT pathway, were identified. Full article

The cancer chemotherapy regimen of a taxane and platinum combination was developed more than forty years ago, yet remains the cornerstone of treatment for several major cancer types today. Although many new agents targeting cancer genes and pathways have been developed and evaluated, none have been sufficient to replace the long-established taxane/platinum combination. This leads us to ponder why, after four decades of colossal efforts, multiple discoveries, and tremendous advances in understanding gene mutations and biology, the development of conceptually superior targeted therapies has not yet achieved overwhelming success in replacing cytotoxic chemotherapy. The concept of targeted therapy is based on the idea that blocking the altered pathway(s) crucial for cancer development (and maintenance), the disturbance in cellular signaling, metabolism, and functions will make the targeted cancer cells unfit and trigger programmed cell death in cancer cells, but without the significant side effects that limit chemotherapy. We propose that the lack of anticipated triumphs of targeted therapy stems from the desensitization of programmed cell death pathways during neoplastic transformation and malignant progression of cancer cells. This renders the targeting drugs largely ineffective at killing cancer cells and mostly insufficient in clinical implements. Recent advances in understanding suggest that, in contrast to targeted therapies, taxanes and platinum agents kill cancer cells by physical rupturing nuclear membranes rather than triggering apoptosis, making their effect independent of the intrinsic cellular programmed cell death mechanism. This new recognition of the non-programmed cell death mechanism in the success of chemotherapeutic agents, such as taxanes and platinum, may inspire oncologists and cancer researchers to focus their efforts more productively on developing effective non-programmed cell death cancer therapies to replace or significantly improve the application of the current standard taxane/platinum regimens. Full article