Vimentin and cytokeratin: Good alone, bad together

Role of Reserve Cells in Metaplasia and the Development of HPV-Associated High-Grade Squamous Intraepithelial Lesion (HSIL) at the Cervical Transformation Zone

Squamous cervical cancers generally arise as a result of persistent infection with high-risk human papillomaviruses (hrHPV) and occur near to the squamocolumnar junction (SCJ) and within the transformation zone (TZ). The susceptibility of the TZ to HPV-related carcinogenesis appears linked to epithelial cell plasticity, with squamous metaplasia originating from a specialized stem cell population at this site. Two alternative cell populations have been implicated: keratin (K)7+ve cuboidal cells located at the SCJ, versus a more broadly distributed K17+ve cervical reserve cell population. To distinguish between the hypotheses, we utilized multiplex immunofluorescence and large-scale digital imaging to map cell populations at the TZ of 165 women with and without hrHPV infections. Our results did not reveal a distinct population of K7+ cuboidal cells at the SCJ, but found instead that the cuboidal and columnar cells of the TZ express K7 and K8 throughout, and lack the p63 transcription factor required for epithelial stratification. Squamous metaplasia and reserve cells, which are defined by their subcolumnar location and pattern of biomarker expression (K5/K17/P63), were conspicuous at cervical crypt entrances within the TZ extending proximally towards the endocervix. In HPV infected tissue, crypt-entrance regions with thin (high-grade squamous intraepithelial lesion (HSIL) pathology showed prominent expression of hrHPV E6/E7 mRNA, as detected by fluorescence in situ hybridization (FISH), and p16/MCM expression, with infection also apparent in neighboring reserve cells. In some instances, normal/uninfected reserve cells (E6/E7 mRNA-ve) and squamous metaplasia were also seen in close proximity to these regions of hrHPV infection, but also extended well beyond the infected area both laterally and by depth. Our results confirm that the reserve cells underneath the columnar epithelia at TZ have the potential to undergo malignant squamous transformation via reserve cell proliferation, in agreement with previous histopathological studies. These translational findings highlight the importance of understanding the molecular biology of the epithelial sites where HPV cancers develop and suggest that in high-risk individuals, treatment strategies should target a wider area than previously thought.

TM9SF1 inhibits colorectal cancer metastasis by targeting Vimentin for Tollip-mediated selective autophagic degradation

Selective autophagy is a finely regulated degradation pathway that can either promote or suppress cancer progression depending on its specific target cargoes. In this study, we report that transmembrane 9 superfamily member 1 (TM9SF1) suppresses colorectal cancer metastasis via selective autophagic degradation of Vimentin. Tm9sf1 knockout significantly increases tumor numbers and size, as well as enhances tumor invasion in colorectal cancer model. In vitro and in vivo phenotypical analyses reveal that TM9SF1 functions as a metastasis suppressor in colorectal cancer. Mechanistically, TM9SF1 facilitates the K63-linked ubiquitination of Vimentin by the E3 ligase TRIM21. The K63-linked ubiquitination of Vimentin serves as a recognition signal for autophagic degradation mediated by autophagic cargo receptor Tollip. Consequently, the downregulation of Vimentin results in a decreased number of F-actin-rich stress fibers and filopodium-like protrusions, ultimately inhibiting colorectal cancer metastasis. Moreover, TM9SF1 is downregulated in colorectal cancer patients with advanced stage compared to those with early stage and associated with favorable prognosis. Overall, our findings identify a novel TM9SF1-TRIM21-Vimentin-Tollip pathway involved in colorectal cancer metastasis, which may provide promising therapeutic targets for the treatment of metastatic colorectal cancer.

Epithelial-Mesenchymal Transition in Cancer: A Focus on Itraconazole, a Hedgehog Inhibitor

Cancer, and the resulting mortality from it, is an ever-increasing concern in global health. Cancer mortality stems from the metastatic progression of the disease, by dissemination of the tumor cells. Epithelial-Mesenchymal Transition, the major hypothesis purported to be the origin of metastasis, confers mesenchymal phenotype to epithelial cells in a variety of contexts, physiological and pathological. EMT in cancer leads to rise of cancer-stem-like cells, drug resistance, relapse, and progression of malignancy. Inhibition of EMT could potentially attenuate the mortality. While novel molecules for inhibiting EMT are underway, repurposing drugs is also being considered as a viable strategy. In this review, Itraconazole is focused upon, as a repurposed molecule to mitigate EMT. Itraconazole is known to inhibit Hedgehog signaling, and light is shed upon the existing evidence, as well as the questions remaining to be answered.

Senescent vascular endothelial cells promote oral squamous cell carcinoma progression through complement C3 activation

OBJECTIVE

The tumour microenvironment (TME) plays a critical role in therapeutic response and clinical outcomes in cancer. Senescent stromal cells have been shown to promote tumour progression; however, the role of senescent vascular endothelial cells (VECs) in oral squamous cell carcinoma (OSCC) remains largely unknown. In this study, we aimed to explore the effects and potential mechanisms of senescent VECs in OSCC progression.

DESIGN

Cisplatin was used to induce senescence in two endothelial cell lines. Senescence-associated β-galactosidase (SA-β-gal) staining, immunoblotting, cell cycle and proliferation assays, and migration and invasion assays were performed to access senescence development and biological behavior. Additionally, RNA sequencing analysis, multiplex immunohistochemical staining, immunoblotting, and xenograft mouse models were used to investigate the senescence-associated secretory phenotype of senescent VECs during OSCC progression and its potential molecular mechanisms.

RESULTS

Cisplatin-induced senescent VECs exhibited senescence-related changes, including positive SA-β-gal expression and upregulation of p16, p21, and p53, along with attenuated proliferation and migration. Notably, cisplatin-induced VEC senescence promoted OSCC cell proliferation, migration, and invasion by activating complement C3. Increased gene and protein levels of C3 were observed in cisplatin-treated senescent VECs. Inhibition of C3 in vitro and in vivo reduced OSCC cell proliferation and invasion.

CONCLUSION

Senescent VECs induced by cisplatin promote OSCC proliferation and invasion through complement C3 activation. Targeting complement C3 in senescent VECs may offer a novel therapeutic strategy for OSCC treatment.

Crip2 affects vascular development by fine-tuning endothelial cell aggregation and proliferation

Endothelial cell adhesion and migration are crucial to various biological processes, including vascular development. The identification of factors that modulate vascular development through these cell functions has emerged as a prominent focus in cardiovascular research. Crip2 is known to play a crucial role in cardiac development, yet its involvement in vascular development and the underlying mechanism remains elusive. In this study, we revealed that Crip2 is expressed predominantly in the vascular system, particularly in the posterior cardinal vein and caudal vein plexus intersegmental vein. Upon Crip2 loss, the posterior cardinal vein plexus and caudal vein plexus are hypoplastic, and endothelial cells exhibit aberrant aggregation. In human umbilical vein endothelial cells (HUVECs), CRIP2 interacts with the cytoskeleton proteins KRT8 and VIM. The absence of CRIP2 negatively regulates their expression, thereby fine-tuning cytoskeleton formation, resulting in a hyperadhesive phenotype. Moreover, CRIP2 deficiency perturbs the VEGFA/CDC42 signaling pathway, which in turn diminishes the migrating capacity of HUVECs. Furthermore, the loss of CRIP2 impairs cell proliferation by affecting its interaction with SRF through PDE10A/cAMP and PDGF/JAK/STAT/SRF signaling. Collectively, our findings delineate a crucial role for CRIP2 in controlling the migration, adhesion and proliferation of endothelial cells, thereby contributing to vascular development in zebrafish. These insights may provide a deeper understanding of the etiology of cardiovascular disorders.

Keratin: A potential driver of tumor metastasis

Keratins, as essential components of intermediate filaments in epithelial cells, play a crucial role in maintaining cell structure and function. In various malignant epithelial tumors, abnormal keratin expression is frequently observed and serves not only as a diagnostic marker but also closely correlates with tumor progression. Extensive research has demonstrated that keratins are pivotal in multiple stages of tumor metastasis, including responding to mechanical forces, evading the immune system, reprogramming metabolism, promoting angiogenesis, and resisting apoptosis. Here we emphasize that keratins significantly enhance the migratory and invasive capabilities of tumor cells, making them critical drivers of tumor metastasis. These findings highlight the importance of targeting keratins as a strategic approach to combat tumor metastasis, thereby advancing our understanding of their role in cancer progression and offering new therapeutic opportunities.

Chemical probes for the identification of the molecular targets of honokiol

Honokiol is a natural product with an interesting array of biological effects, including significant anti-tumor properties. However, full exploration of its therapeutic potential is hampered by its modest pharmacokinetic profile and by the lack of synthetic methods that allow to obtain specifically designed derivatives with improved properties. In addition, the specific molecular targets of honokiol remain poorly understood, a fact that limits the search of alternative hits for subsequent optimization programs. In this work we describe an optimized series of synthetic routes that allow to access to a variety of honokiol derivatives, including a set of minimalist photoaffinity probes to map potential protein targets in live cells. Chemical proteomic studies of the most potent probe revealed a defined set of proteins as the cellular targets of honokiol. Significantly, up to the 62 % of the identified proteins have described roles in cancer, highlighting their potential relationship with the antitumor effects of honokiol. Furthermore, several of the top hits have been validated as direct binding partners of honokiol by cellular thermal shift assay (CETSA). In sum, the work described herein provides the first landscape of the cellular targets of honokiol in living cells and contributes to define the specific molecular pathways affected by this natural product.

Research progress of mitochondria and cytoskeleton crosstalk in tumour development

During tumour progression, organelle function undergoes dramatic changes, and crosstalk among organelles plays a significant role. Crosstalk between mitochondria and other organelles such as the endoplasmic reticulum and cytoskeleton has focussed attention on the mechanisms of tumourigenesis. This review demonstrates an overview of the molecular structure of the mitochondrial-cytoskeletal junction and its biological interactions. It also presents a detailed and comprehensive description of mitochondrial-cytoskeletal crosstalk in tumour occurrence and development, including tumour cell proliferation, apoptosis, autophagy, metabolic rearrangement, and metastasis. Finally, the application of crosstalk in tumour therapy, including drug combinations and chemoresistance, is discussed. This review offers a theoretical basis for establishing mitochondrial-cytoskeletal junctions as therapeutic targets, and offers novel insights into the future management of malignant tumours.

UHRF1 promotes epithelial-mesenchymal transition mediating renal fibrosis by activating the TGF-β/SMAD signaling pathway

Renal fibrosis is widely recognized as the ultimate outcome of many chronic kidney diseases. The process of epithelial-mesenchymal transition (EMT) plays a critical role in the progression of fibrosis following renal injury. UHRF1, as a critical epigenetic regulator, may play an essential role in the pathogenesis and progression of renal fibrosis and EMT. However, the potential mechanisms remain to be elucidated. We aim to investigate the role of UHRF1 in EMT and renal fibrosis and to evaluate the potential benefits of Hinokitiol in preventing renal fibrosis. Based on data from the GEO and Nephroseq databases, UHRF1 exhibited high expression levels in the unilateral ureteral obstruction (UUO) model and in patients with nephropathy. Gene set enrichment analysis predicted that UHRF1 may function through the TGF-β signaling pathway in fibrosis. By establishing a TGF-β1-stimulated HK2 cell model and animal models of renal fibrosis induced by UUO and folic acid, we confirmed that UHRF1 was highly expressed in both in vitro and in vivo models of renal fibrosis. After knockdown of UHRF1 in vitro, we found that the TGF-β/SMAD signaling pathway was inhibited, renal tubular epithelial cell EMT was reduced and renal fibrosis was attenuated. Hinokitiol has been reported to reduce the expression of UHRF1 mRNA and protein. We observed that inhibition of UHRF1 with Hinokitiol ameliorated induced EMT and renal fibrosis by reducing SMAD2/3 phosphorylation in vivo and in vitro. Taken together, our data demonstrated that the upregulation of UHRF1 accelerated the EMT of renal tubular cells and renal fibrosis through the TGF-β/SMAD signaling pathway. Hinokitiol may ameliorate renal fibrosis by suppressing the expression of UHRF1 in the kidney.

Fibrotic Changes in Rhegmatogenous Retinal Detachment

Rhegmatogenous retinal detachment (RRD) is a sight-threatening condition involving retinal detachment and the accumulation of fluid in the subretinal space. Proliferative vitreoretinopathy (PVR) is a pathologic complication that develops after RRD surgery, and approximately 5-10% of RRD cases develop post-operative PVR. Prolonged inflammation in the wound healing process, epithelial-mesenchymal transition (EMT), retinal pigment epithelial (RPE) cell migration and proliferation, and epiretinal, intraretinal, and subretinal fibrosis are typical in the formation of PVR. RPE cells undergo EMT and become fibroblast-like cells that migrate to the retina and vitreous, promoting PVR formation. Fibroblasts transform into myofibroblasts, which promote fibrosis by overproducing the extracellular matrix (ECM). RPE cells, fibroblasts, glial cells, macrophages, T lymphocytes, and increased ECM production form contractile epiretinal membranes. Cytokine release, complement activation, RPE cells, glial cells, and endothelial cells are all involved in retinal immune responses. Normally, wounds heal within 4 to 6 weeks, including hemostasis, inflammation, proliferation, and remodeling phases. Properly initiated inflammation, complement activation, and the function of neutrophils and glial cells heal the wound in the first stage. In a retinal wound, glial cells proliferate and fill the injured area. Gliosis tries to protect the neurons and prevent damage, but it becomes harmful when it causes scarring. If healing is complicated, prolonged inflammation leads to pathological fibrosis. Currently, there is no preventive treatment for the formation of PVR, and it is worth studying in the future.

Single-cell differential detergent fractionation for detection of cytokeratin 8 proteoforms

Simultaneous profiling of proteoforms and nucleic acids at the single-cell level, i.e., multi omics, directly links the central dogma. However, current single-cell approaches are limited in their ability to identify proteoforms while preserving the nucleus for further analysis. This limitation is especially pronounced in proteins where their proteoforms present diverse biological functions such as cytokeratin 8 (CK8), which, while commonly known for its structural role, is also involved in several diseases. Here, we present a single-cell western blot (scWB) integrated with differential detergent fractionation (DDF) to selectively solubilize and separate CK8 proteoforms while preserving nuclear integrity for subsequent nucleus-based assays. We report on assay development, including screening a panel of lysis buffers based on nonionic detergents and electrophoresis conditions to achieve a separation resolution between two proteoforms of up to 0.94 with an electric field of 30 V/cm, while preserving an intact nucleus. The cytoplasm-specific lysis approach (DDF buffer) demonstrated comparable solubilization efficiency to whole-cell solubilization (RIPA buffer), achieving proteoform solubilization in 14.3% and 10.3% of solubilized cells using DDF and RIPA buffers, respectively, while keeping the nucleus intact. To understand the broad applicability of the assay conditions, we scrutinized electrophoresis performance for resolving CK8 proteoforms across a panel of widely used breast cancer cell lines (MCF7, SKBR3, and MDA-MB-231), showing presence of proteoforms only in MCF7. Our approach allows for tailored solubilization, achieving reliable proteoform detection and nuclear retention across different cell types. Proteoform profiling at the single-cell level forms a basis for the exploration of the role of specific CK8 molecular forms in cellular processes.

Implications of Mineralization Biomarkers in Breast Cancer Outcomes Beyond Calcifications

The aim of this work was to explore the biomarkers associated with epithelial to mesenchymal transition (EMT) and mineralization processes as new prognostic factors across different breast cancer phenotypes. To this end, 133 breast biopsies, including benign and malignant lesions, with or without microcalcifications, were retrospectively collected. Immunohistochemical analysis was performed to evaluate the expression of vimentin, BMP-2, BMP-4, RANKL, Runx2, OPN, PTX3, and SDF-1, while Kaplan-Meier plots were used to assess their prognostic impact on overall survival in a dataset of 2976 breast cancer patients. The expression of vimentin, BMP-2, BMP-4, and SDF-1 was significantly higher in malignant lesions compared to benign ones, regardless of the presence of microcalcifications. Notably, these markers showed no correlation with traditional prognostic factors, such as tumor grade or hormone receptor status. The bioinformatics analysis provided valuable insights into the possible prognostic and therapeutic significance of BMP-2, BMP-4, SDF-1, and vimentin in breast cancer. In fact, all these biomarkers impact on the overall survival in specific molecular breast cancer types. In addition, high expression of SDF-1 and vimentin is able to predict the response to chemotherapy. The findings here reported suggest that vimentin, BMP-2, BMP-4, and SDF-1 could be independent prognostic biomarkers in breast cancer, providing insights beyond traditional clinical factors.

Triple-Negative Breast Cancer Progression and Drug Resistance in the Context of Epithelial-Mesenchymal Transition

Triple-negative breast cancer (TNBC) is one of the most difficult subtypes of breast cancer to treat due to its distinct clinical and molecular characteristics. Patients with TNBC face a high recurrence rate, an increased risk of metastasis, and lower overall survival compared to other breast cancer subtypes. Despite advancements in targeted therapies, traditional chemotherapy (primarily using platinum compounds and taxanes) continues to be the standard treatment for TNBC, often with limited long-term efficacy. TNBC tumors are heterogeneous, displaying a diverse mutation profile and considerable chromosomal instability, which complicates therapeutic interventions. The development of chemoresistance in TNBC is frequently associated with the process of epithelial-mesenchymal transition (EMT), during which epithelial tumor cells acquire a mesenchymal-like phenotype. This shift enhances metastatic potential, while simultaneously reducing the effectiveness of standard chemotherapeutics. It has also been suggested that EMT plays a central role in the development of cancer stem cells. Hence, there is growing interest in exploring small-molecule inhibitors that target the EMT process as a future strategy for overcoming resistance and improving outcomes for patients with TNBC. This review focuses on the progression and drug resistance of TNBC with an emphasis on the role of EMT in these processes. We present TNBC-specific and EMT-related molecular features, key EMT protein markers, and various signaling pathways involved. We also discuss other important mechanisms and factors related to chemoresistance in TNBC within the context of EMT, highlighting treatment advancements to improve patients' outcomes.

Dietary limonene promotes gastrointestinal barrier function via upregulating tight/adherens junction proteins through cannabinoid receptor type-1 antagonistic mechanism and alters cellular metabolism in intestinal epithelial cells

Limonene, a dietary monocyclic monoterpene commonly found in citrus fruits and various aromatic plants, has garnered increasing interest as a gastrointestinal protectant. This study aimed to assess the effects of limonene on intestinal epithelial barrier function and investigate the involvement of cannabinoid receptor type-1 (CB1R) in vitro. Additionally, the study focused on examining the metabolomic changes induced by limonene in the intestinal epithelial cells (Caco-2). Initial analysis of transepithelial electrical resistance (TEER) revealed that both l-limonene and d-limonene, isomers of limonene, led to a dose- and time-dependent increase in TEER in normal cells and those inflamed by pro-inflammatory cytokines mixture (CytoMix). Furthermore, both types of limonene reduced CytoMix-induced paracellular permeability, as demonstrated by a decrease in Lucifer yellow flux. Moreover, d-limonene and l-limonene treatment increased the expression of tight junction molecules (TJs) such as occludin, claudin-1, and ZO-1, at both the transcriptional and translational levels. d-Limonene upregulates E-cadherin, a molecule involved in adherens junctions (AJs). Mechanistic investigations demonstrated that d-limonene and l-limonene treatment significantly inhibited CB1R at the protein, while the mRNA level remained unchanged. Notably, the inhibitory effect of d-limonene on CB1R was remarkably similar to that of pharmacological CB1R antagonists, such as rimonabant and ORG27569. d-limonene also alters Caco-2 cell metabolites. A substantial reduction in β-glucose and 2-succinamate was detected, suggesting limonene may impact intestinal epithelial cells' glucose uptake and glutamate metabolism. These findings suggest that d-limonene's CB1R antagonistic property could effectively aid in the recovery of intestinal barrier damage, marking it a promising gastrointestinal protectant.

Combined targeting of TCF7L1/2, PTEN, CDK6, and BCCIP by microRNA miR-29c-3p is associated with reduced invasion and proliferation of endometriotic cells

Purpose

Endometriosis is a chronic gynecological disorder associated with pain symptoms and infertility. The expression of microRNA miR-29c-3p is dysregulated in endometriosis. We aimed to identify novel molecular targets of miR-29c-3p functionally linked to proliferation and invasive growth in endometriosis.

Methods

The epithelial endometriotic cell line 12Z and primary endometriotic stromal cells (PESC) were transfected with control miRNA or pre-miR-29c-3p, and subjected to cell cycle analysis, cell viability, wound healing, and Matrigel invasion assays. Expression of bioinformatically predicted miR-29c-3p targets was analyzed by qPCR and western blot. Target gene expression in endometriotic lesions and healthy endometrium was studied in the EndometDB endometriosis database.

Results

miR-29c-3p decreased 12Z and PESC cell viability and the proportion of PESC in the S-phase. 12Z cell invasion, but not migration, was decreased after miR-29c-3p upregulation. miR-29c-3p decreased the mRNA expression of CDK6, BCCIP, TCF7L1, TCF7L2, PTEN, COL4A1, E-Cadherin, and N-Cadherin. A decrease of CDK6 and PTEN and an increase of p21 were confirmed at the protein level. EndometDB database analysis demonstrated dysregulated expression of the selected targets in both deep endometriosis and ovarian endometriosis.

Conclusions

miR-29c-3p effectively curbs endometriotic cell proliferation and invasion by combined inhibition of cell cycle regulators and transcription factors, unveiling a promising therapeutic strategy.

Exploring vimentin's role in breast cancer via PICK1 alternative polyadenylation and the miR-615-3p-PICK1 interaction

Breast cancer continues to be a major health issue for women worldwide, with vimentin (VIM) identified as a crucial factor in its progression due to its role in cell migration and the epithelial-to-mesenchymal transition (EMT). This study focuses on elucidating VIM's regulatory mechanisms on the miR-615-3p/PICK1 axis. Utilizing the 4T1 breast cancer cell model, we first used RNA-seq and proteomics to investigate the changes in the APA of PICK1 following VIM knockout (KO). These high-throughput analyses aimed to uncover the underlying transcriptional and proteomic alterations associated with VIM's influence on breast cancer cells. RNA-seq and proteomic profiling revealed significant APA in PICK1 following VIM KO, suggesting a novel mechanism by which VIM regulates breast cancer progression. Validation experiments confirmed that VIM KO affects the miR-615-3p-PICK1 axis, with miR-615-3p's regulation of PICK1 being contingent upon the APA of PICK1. These findings highlight the complex interplay between VIM, miR-615-3p, and PICK1 in the regulation of breast cancer cell behavior. This study reveals that vimentin affects the miR-615-3p-PICK1 axis through APA, revealing the key role of VIM in cancer progression. Opened up new avenues for targeted cancer therapy, with a focus on regulating the interaction between APA and miR-615-3p-PICK1.

Cytoskeletal Vimentin Directs Cell-Cell Transmission of Hepatitis C Virus

Hepatitis C virus (HCV) is a major human pathogen causing liver diseases. Although direct-acting antiviral agents effectively inhibit HCV infection, cell-cell transmission remains a critical venue for HCV persistence in vivo. However, the underlying mechanism of how HCV spreads intercellularly remains elusive. Here, we demonstrated that vimentin, a host intermediate filaments protein, is dispensable for HCV infection in cell models but essential for simulated in vivo infection in differentiated hepatocytes. Genetic removal of vimentin markedly and specifically disrupts HCV cell-cell transmission without influencing cell-free infection. Through mutual co-immunoprecipitation screening, we identified that the N-terminal 1-95 amino acids of vimentin exclusively interact with the HCV envelope protein E1. Introducing either full-length or head region of vimentin is capable of restoring the cell-cell transmission deficiency in vimentin-knockout cells. Moreover, we showed that it is vimentin on the plasma membrane of recipient cells that orchestrates HCV cell-cell transmission. Consequently, vimentin antibody, either applied individually or in combination with HCV neutralizing antibody, exerts pronounced inhibition of HCV cell-cell transmission. Together, the results unveil an unrecognized function of vimentin as a unique venue dominating viral transmission, providing novel insights into propelling advancements in vimentin-targeted anti-HCV therapies.

KIF4A promotes epithelial-mesenchymal transition by activating the TGF-β/SMAD signaling pathway in glioma cells

Gliomas are the most prevalent type of primary brain tumor, with poor prognosis reported in patients with high-grade glioma. Kinesin family member 4 A (KIF4A) stimulates the proliferation, migration, and invasion of tumor cells. However, its function in gliomas has not been clearly established. Therefore, this study aimed to investigate the effects of KIF4A on the epithelial-mesenchymal transition and invasion of glioma cells. We searched The Cancer Genome Atlas and Chinese Glioma Genome Atlas databases to identify KIF4A-related signaling pathways and downstream genes. We further validated them using western blotting, transwell migration and invasion, wound-healing scratch, and dual-luciferase reporter assays in U251 and U87 human glioblastoma cells. Our analysis of the Cancer Genome Atlas and Chinese Glioma Genome Atlas data showed elevated KIF4A expression in patients with gliomas and was associated with clinical grade. Here, KIF4A overexpression promoted the migration, invasion, and proliferation of glioma cells, whereas KIF4A knockdown showed contrasting results. Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) analyses demonstrated that KIF4A positively controls TGF-β/SMAD signaling in glioma cells. Additionally, genetic correlation analysis revealed that KIF4A transcriptionally controls benzimidazoles-1 expression in glioma cells. KIF4A promotes the epithelial-mesenchymal transition by regulating the TGF-β/SMAD signaling pathway via benzimidazoles-1 in glioma cells.

Components of the Endosome-Lysosome Vesicular Machinery as Drivers of the Metastatic Cascade in Prostate Cancer

Prostate cancer remains a significant global health concern, with over 1.4 million new cases diagnosed and more than 330,000 deaths each year. The primary clinical challenge that contributes to poor patient outcomes involves the failure to accurately predict and treat at the onset of metastasis, which remains an incurable stage of the disease. This review discusses the emerging paradigm that prostate cancer metastasis is driven by a dysregulation of critical molecular machinery that regulates endosome-lysosome homeostasis. Endosome and lysosome compartments have crucial roles in maintaining normal cellular function but are also involved in many hallmarks of cancer pathogenesis, including inflammation, immune response, nutrient sensing, metabolism, proliferation, signalling, and migration. Here we discuss new insight into how alterations in the complex network of trafficking machinery, responsible for the microtubule-based transport of endosomes and lysosomes, may be involved in prostate cancer progression. A better understanding of endosome-lysosome dynamics may facilitate the discovery of novel strategies to detect and manage prostate cancer metastasis and improve patient outcomes.

The Cancer Chimera: Impact of Vimentin and Cytokeratin Co-Expression in Hybrid Epithelial/Mesenchymal Cancer Cells on Tumor Plasticity and Metastasis

The epithelial-mesenchymal transition (EMT) program is critical to metastatic cancer progression. EMT results in the expression of mesenchymal proteins and enhances migratory and invasive capabilities. In a small percentage of cells, EMT results in the expression of stemness-associated genes that provide a metastatic advantage. Although EMT had been viewed as a binary event, it has recently become clear that the program leads to a spectrum of phenotypes, including hybrid epithelial/mesenchymal (E/M) cells that have significantly greater metastatic capability than cells on the epithelial or mesenchymal ends of the spectrum. As hybrid E/M cells are rarely observed in physiological, non-diseased states in the adult human body, these cells are potential biomarkers and drug targets. Hybrid E/M cells are distinguished by the co-expression of epithelial and mesenchymal proteins, such as the intermediate filament proteins cytokeratin (CK; epithelial) and vimentin (VIM; mesenchymal). Although these intermediate filaments have been extensively used for pathological characterization and detection of aggressive carcinomas, little is known regarding the interactions between CK and VIM when co-expressed in hybrid E/M cells. This review describes the characteristics of hybrid E/M cells with a focus on the unique co-expression of VIM and CK. We will discuss the structures and functions of these two intermediate filament proteins and how they may interact when co-expressed in hybrid E/M cells. Additionally, we review what is known about cell-surface expression of these intermediate filament proteins and discuss their potential as predictive biomarkers and therapeutic targets.

Mesonephric adenocarcinoma of the uterine cervix with a prominent spindle cell component

Mesonephric adenocarcinomas (MAs) with spindle cell components are rare malignant cervical tumours. In the present study, a retrospective analysis of these tumours was performed. Clinicopathological data were gathered from electronic surgical pathology records, and both immunohistochemistry and targeted next-generation sequencing (NGS) were performed. The present study included three postmenopausal female patients diagnosed with primary uterine cervical MA with prominent spindle cell components, aged 51-60 years. All patients underwent hysterectomy with bilateral salpingo-oophorectomy and pelvic lymph node dissection. There were no recurrences or deaths after surgery. NGS analysis identified KRAS mutations in 2 cases and a PIK3-catalytic subunit α (PIK3CA) mutation in another. Spindle cell components may indicate MAs at an advanced stage. Spindle cell components in MAs are diagnostic pitfalls, and the use of immunohistochemical panels and molecular detection cases with overlapping morphological features is recommended. While KRAS mutations are the most common types of mutations in MAs with spindle cell components, the present study demonstrates that PIK3CA mutations can also occur independently in cases without KRAS mutations.

Dysregulated lncSNHG12 suppresses the invasion and migration of trophoblasts by regulating Dio2/Snail axis to involve in recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is a complex pathological process involving diverse factors, in which the dysregulated functions of trophoblasts cannot be ignored. Long noncoding RNA (lncRNA) has been reported to play a significant role in regulating the functions of trophoblasts in RSA. However, the impact and potential mechanism of lncRNA small nucleolar RNA host gene 12 (lncSNHG12) remain unclear. The role of lncSNHG12 in RSA was investigated through in vivo experiments and clinical samples. Co-IP and RNA pull down were conducted to explore the molecular mechanisms in trophoblasts. Our results showed that lncSNHG12 promoted the migration and invasion of trophoblasts by interacting with Iodothyronine deiodinase 2 (Dio2), which regulating the EMT process of trophoblasts by interacting with Snail. Moreover, in vivo experiments confirmed that lncSNHG12 could improve the fetal absorption rate of the abortion mice. The clinical samples revealed that lncSNHG12, Dio2 and Snail were down-regulated in the villous tissues of RSA patients, and positive correlations were confirmed between lncSNHG12 and Dio2, as well as Dio2 and Snail. In summary, the lncSNHG12/Dio2/Snail axis might be involved in the development of RSA by regulating the invasion and migration of trophoblasts. Abbreviations: RSA, recurrent spontaneous abortion; EVTs, extravillous trophoblasts; EMT, epithelial-to-mesenchymal transition; lncRNA, long non-coding RNA; Dio2, iodothyronine deiodinase 2; SNHGs, small nuclear RNA host genes; snoRNAs, small nuclear cell RNAs; LPS, lipopolysaccharide; De, derived decidua; Jz, junctional zone; Lz, labyrinth zones; RIP, RNA Binding Protein Immunoprecipitation; Co-IP, Co-Immunoprecipitation; RPISeq, RNA-Protein Interaction Prediction.

Histopathological and immunohistochemical analysis of a suspected extraskeletal osteosarcoma in a rabbit (Oryctolagus cuniculus)

An 8-year-old male rabbit (Oryctolagus cuniculus) presented with a subcutaneous mass in the proximal region of the fourth and accessory digit measuring 5.5 x 3.5 x 5.2cm. The mass was non-alopecic and exhibited irregular surface, ulceration and necrosis with predominantly pale and light brown coloring. Radiography revealed no involvement of bone and adjacent periosteum. The mass was marginally resected and the electrochemotherapy (ECT) was performed on the surgical bed. Histopathology and immunohistochemical analysis revealed positive reactions for Vimentin, Runx-2 and ki-67, leading to a diagnosis of extraskeletal osteosarcoma (ESOS). This report described a case of ESOS in a rabbit, thereby delineating its clinical presentation, anatomopathological characteristics, diagnostic modalities and recommended therapeutic interventions.

Columbianadin ameliorates rheumatoid arthritis by attenuating synoviocyte hyperplasia through targeted vimentin to inhibit the VAV2/Rac-1 signaling pathway

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune disease pathologically characterized by synovial inflammation. The abnormal activation of synoviocytes seems to accompany the progression of RA. The role and exact molecular mechanism in RA of columbianadin (CBN) which is a natural coumarin is still unclear.

OBJECTIVES

The present research aimed to investigate the effect of vimentin on the abnormal growth characteristics of RA synoviocytes and the targeted regulatory role of CBN.

METHODS

Cell migration and invasion were detected using the wound healing and transwell method. Mechanistically, the direct molecular targets of CBN were screened and identified by activity-based protein profiling. The expression of relevant proteins and mRNA in cells and mouse synovium was detected by western blotting and qRT-PCR. Changes in the degree of paw swelling and body weight of mice were recorded. H&E staining, toluidine blue staining, and micro-CT were used to visualize the degree of pathological damage in the ankle joints of mice. Small interfering RNA and plasmid overexpression of vimentin were used to observe their effects on MH7A cell proliferation, migration, apoptosis, and downstream molecular signaling.

RESULTS

The TNF-α-induced proliferation and migration of MH7A cells could be significantly repressed by CBN (25,50 μM), and the expression of apoptosis and autophagy-associated proteins could be modulated. Furthermore, CBN could directly bind to vimentin and inhibit its expression and function in synoviocytes, thereby ameliorating foot and paw swelling and joint damage in CIA mice. Silencing and overexpression of vimentin might be involved in developing RA synovial hyperplasia and invasive cartilage by activating VAV2 phosphorylation-mediated expression of Rac-1, which affects abnormal growth characteristics, such as synoviocyte invasion and migration.

CONCLUSION

CBN-targeted vimentin restrains the overactivation of RA synoviocytes thereby delaying the pathological process in CIA mice, which provides valuable targets and insights for understanding the pathological mechanisms of RA synovial hyperplasia.

Leader Cells: Invade and Evade-The Frontline of Cancer Progression

Metastasis is the leading cause of cancer-related mortality; however, a complete understanding of the molecular programs driving the metastatic cascade is lacking. Metastasis is dependent on collective invasion-a developmental process exploited by many epithelial cancers to establish secondary tumours and promote widespread disease. The key drivers of collective invasion are "Leader Cells", a functionally distinct subpopulation of cells that direct migration, cellular contractility, and lead trailing or follower cells. While a significant body of research has focused on leader cell biology in the traditional context of collective invasion, the influence of metastasis-promoting leader cells is an emerging area of study. This review provides insights into the expanded role of leader cells, detailing emerging evidence on the hybrid epithelial-mesenchymal transition (EMT) state and the phenotypical plasticity exhibited by leader cells. Additionally, we explore the role of leader cells in chemotherapeutic resistance and immune evasion, highlighting their potential as effective and diverse targets for novel cancer therapies.

Keratin 8/18a.1 Expression Influences Embryonic Neural Crest Cell Dynamics and Contributes to Postnatal Corneal Regeneration in Zebrafish

A complete understanding of neural crest cell mechanodynamics during ocular development will provide insight into postnatal neural crest cell contributions to ophthalmic abnormalities in adult tissues and inform regenerative strategies toward injury repair. Herein, single-cell RNA sequencing in zebrafish during early eye development revealed keratin intermediate filament genes krt8 and krt18a.1 as additional factors expressed during anterior segment development. In situ hybridization and immunofluorescence microscopy confirmed krt8 and krt18a.1 expression in the early neural plate border and migrating cranial neural crest cells. Morpholino oligonucleotide (MO)-mediated knockdown of K8 and K18a.1 markedly disrupted the migration of neural crest cell subpopulations and decreased neural crest cell marker gene expression in the craniofacial region and eye at 48 h postfertilization (hpf), resulting in severe phenotypic defects reminiscent of neurocristopathies. Interestingly, the expression of K18a.1, but not K8, is regulated by retinoic acid (RA) during early-stage development. Further, both keratin proteins were detected during postnatal corneal regeneration in adult zebrafish. Altogether, we demonstrated that both K8 and K18a.1 contribute to the early development and postnatal repair of neural crest cell-derived ocular tissues.

Circulating tumor cells: from new biological insights to clinical practice

The primary reason for high mortality rates among cancer patients is metastasis, where tumor cells migrate through the bloodstream from the original site to other parts of the body. Recent advancements in technology have significantly enhanced our comprehension of the mechanisms behind the bloodborne spread of circulating tumor cells (CTCs). One critical process, DNA methylation, regulates gene expression and chromosome stability, thus maintaining dynamic equilibrium in the body. Global hypomethylation and locus-specific hypermethylation are examples of changes in DNA methylation patterns that are pivotal to carcinogenesis. This comprehensive review first provides an overview of the various processes that contribute to the formation of CTCs, including epithelial-mesenchymal transition (EMT), immune surveillance, and colonization. We then conduct an in-depth analysis of how modifications in DNA methylation within CTCs impact each of these critical stages during CTC dissemination. Furthermore, we explored potential clinical implications of changes in DNA methylation in CTCs for patients with cancer. By understanding these epigenetic modifications, we can gain insights into the metastatic process and identify new biomarkers for early detection, prognosis, and targeted therapies. This review aims to bridge the gap between basic research and clinical application, highlighting the significance of DNA methylation in the context of cancer metastasis and offering new avenues for improving patient outcomes.

TRIM33 enhances the ubiquitination of TFRC to enhance the susceptibility of liver cancer cells to ferroptosis

BACKGROUND

Hepatocellular carcinoma (HCC) is a common malignancy, and ferroptosis is a novel form of cell death driven by excessive lipid peroxidation. In recent years, ferroptosis has been widely utilized in cancer treatment, and the ubiquitination modification system has been recognized to play a crucial role in tumorigenesis and metastasis. Increasing evidence suggests that ubiquitin regulates ferroptosis-related substrates involved in this process. However, the precise mechanism of utilizing ubiquitination modification to regulate ferroptosis for HCC treatment remains unclear.

METHODS

In this study, we detected the expression of TRIM33 in HCC using immunohistochemistry and western blotting techniques. The functional role of TRIM33 was verified through both in vitro and in vivo experiments. To evaluate the level of ferroptosis, mitochondrial superoxide levels, MDA levels, Fe2+ levels, and cell viability were assessed. Downstream substrates of TRIM33 were screened and confirmed via immunoprecipitation, immunofluorescence staining, and ubiquitination modification experiments.

RESULTS

Our findings demonstrate that TRIM33 inhibits the growth and metastasis of HCC cells both in vitro and in vivo while promoting their susceptibility to ferroptosis. Mechanistically speaking, TRIM33 induces cellular ferroptosis through E3 ligase-dependent degradation of TFRC-a known inhibitor of this process-thus elucidating the specific type and site at which TFRC undergoes modification by TRIM33.

CONCLUSION

In summary, our study reveals an important role for TRIM33 in HCC treatment while providing mechanistic support for its function. Additionally highlighted is the significance of ubiquitination modification leading to TFRC degradation-an insight that may prove valuable for future targeted therapies.

p38 Signaling Mediates Naringin-Induced Osteogenic Differentiation of Porcine Metanephric Mesenchymal Cells

OBJECTIVE

To explore the potential of metanephric mesenchymal cells (MMCs) for osteogenesis and naringin's ability to enhance this process and its molecular mechanism.

METHODS

Porcine MMCs at 70 days of gestation were used as tool cells, cultured in osteogenic induction medium, identified by immunocytochemistry staining. Osteogenic potential of porcine MMCs and naringin's ability to enhance this process was tested by detecting changes in cell viability, alkaline phosphatase (ALP) activity, the expression of runt-related transcription factor 2 (Runx2), osteopontin (OPN) and osteocalcin (OCN), and the formation of mineralized nodules, and the application of the p38 signaling pathway inhibitor SB203580 vitiated the osteogenesis-promoting effect of naringin.

RESULTS

Immunocytochemical staining showed that the cells were Vimentin and Six2(+), E-cadherin and CK-18(-). Naringin can activate the p38 signaling pathway to enhance the osteogenesis of porcine MMCs by increasing cell viability, ALP activity, the expressions of Runx2, OPN and OCN, and the formation of mineralized nodules (P<0.05). The application of p38 signaling pathway inhibitor SB203580 vitiated the osteogenesis-promoting effect of naringin, manifested by decreased ALP activity, the expressions of Runx2, OPN and OCN, and the formation of mineralized nodules (P<0.05).

CONCLUSION

Naringin, the active ingredient of Chinese herbal medicine Rhizoma Drynariae for nourishing Shen (Kidney) and strengthening bone, enhances the osteogenic differentiation of renal MMCs through the p38 signaling pathway.

Common lizard primary oviduct cell culture: A model system for the genetic and cellular basis of oviparity and viviparity

Reproduction by egg-laying (oviparity) or live-bearing (viviparity) is a genetically determined trait fundamental to the biology of amniotes. Squamates are an emerging model for the genetics of reproductive mode yet lack cell culture models valuable for exploring molecular mechanisms. Here, we report a novel primary culture model for reproductive biology: cell cultures derived from the oviduct tissues (infundibulum, uterus and vagina) of oviparous and viviparous common lizards (Lacertidae: Zootoca vivipara). We maintained and expanded these cultures for over 100 days, including repeated subculturing and successful revival of cryopreserved cells. Immunocytochemical investigation suggested expression of both epithelial and fibroblast-like proteins, and RNA sequencing of cultured cells as compared to in vivo oviduct tissue showed changes in gene expression in response to the cell culture environment. Despite this, we confirmed the maintenance of distinct gene expression patterns in viviparous and oviparous cells after 60+ days of cell culture, finding 354 differentially expressed genes between viviparous and oviparous cells. Furthermore, we confirmed the expression of 15 viviparity-associated candidate genes in cells maintained for 60+ days in culture. Our study demonstrates the feasibility and utility of oviduct cell culture for molecular analysis of reproductive mode and provides a tool for future genetic experiments.

ARHGAP4 promotes colon cancer metastasis through the TGF-β signaling pathway and may be associated with T cell exhaustion

BACKGROUND

Colon cancer is a prevalent invasive neoplasm in the gastrointestinal system with a high degree of malignancy. Despite extensive research, the underlying mechanisms of its recurrence and metastasis remain elusive.Rho GTPase activating protein 4 (ARHGAP4), a member of the small GTPases protein family, may be closely related to tumor metastasis, and its expression is increased in colon cancer. However, the role of ARHGAP4 in colon cancer metastasis is uncertain. This study investigates the impact of ARHGAP4 on the metastasis of colon cancer cells. Our objective is to determine the role of ARHGAP4 in regulating the invasive behavior of colon cancer cells.

METHODS

We downloaded colon adenocarcinoma (COAD) data from the Cancer Genome Atlas (TCGA), and performed differential analysis and survival analysis. By using the CIBERSORT algorithm, we evaluated the proportion of infiltrating immune cells in colon cancer. We further analyzed whether ARHGAP4 is associated with T cell exhaustion. Finally, we investigated the impact of ARHGAP4 knockdown on the migration and invasion of colon cancer cells through in vitro cell experiments. Additionally, we utilized western blotting to assess the expression of protein related to the TGF-β signaling pathway and epithelial-mesenchymal transition (EMT).

RESULTS

We found that ARHGAP4 is upregulated in colon cancer. Subsequent survival analysis revealed that the high-expression group had significantly lower survival rates compared to the low-expression group. Immune infiltration analysis showed that ARHGAP4 was not only positively correlated with CD8+ T cells, but also positively correlated with T cell exhaustion markers programmed cell death 1 (PDCD-1), cytotoxic T-lymphocyte associated protein 4 (CTLA-4), and lymphocyte activating 3 (LAG-3). In vitro cell experiments, the knockdown of ARHGAP4 inhibited the migration and invasion of colon cancer cells. Among EMT-related proteins, when ARHGAP4 was knocked down, the expression of E-cadherin was increased, while the expression of N-cadherin and Vimentin was decreased. Meanwhile, the expression of TGF-β1, p-Smad2, and p-Smad3, which are associated with the TGF-β/Smad pathway, all decreased.

CONCLUSION

ARHGAP4 promotes colon cancer metastasis through the TGF-β/Smad signaling pathway and may be associated with T cell exhaustion. It plays an important role in the progression of colon cancer and may serve as a potential target for diagnosis and treatment of colon cancer.

Flow cytometric analysis for Ki67 assessment in formalin-fixed paraffin-embedded breast cancer tissue

BACKGROUND

Pathologists commonly employ the Ki67 immunohistochemistry labelling index (LI) when deciding appropriate therapeutic strategies for patients with breast cancer. However, despite several attempts at standardizing the Ki67 LI, inter-observer and inter-laboratory bias remain problematic. We developed a flow cytometric assay that employed tissue dissociation, enzymatic treatment and a gating process to analyse Ki67 in formalin-fixed paraffin-embedded (FFPE) breast cancer tissue.

RESULTS

We demonstrated that mechanical homogenizations combined with thrombin treatment can be used to recover efficiently intact single-cell nuclei from FFPE breast cancer tissue. Ki67 in the recovered cell nuclei retained reactivity against the MIB-1 antibody, which has been widely used in clinical settings. Additionally, since the method did not alter the nucleoskeletal structure of tissues, the nuclei of cancer cells can be enriched in data analysis based on differences in size and complexity of nuclei of lymphocytes and normal mammary cells. In a clinical study using the developed protocol, Ki67 positivity was correlated with the Ki67 LI obtained by hot spot analysis by a pathologist in Japan (rho = 0.756, P < 0.0001). The number of cancer cell nuclei subjected to the analysis in our assay was more than twice the number routinely checked by pathologists in clinical settings.

CONCLUSIONS

The findings of this study showed the application of this new flow cytometry method could potentially be used to standardize Ki67 assessments in breast cancer.

Lack of basic rationale in epithelial-mesenchymal transition and its related concepts

Epithelial-mesenchymal transition (EMT) is defined as a cellular process during which epithelial cells acquire mesenchymal phenotypes and behavior following the downregulation of epithelial features. EMT and its reversed process, the mesenchymal-epithelial transition (MET), and the special form of EMT, the endothelial-mesenchymal transition (EndMT), have been considered as mainstream concepts and general rules driving developmental and pathological processes, particularly cancer. However, discrepancies and disputes over EMT and EMT research have also grown over time. EMT is defined as transition between two cellular states, but it is unanimously agreed by EMT researchers that (1) neither the epithelial and mesenchymal states nor their regulatory networks have been clearly defined, (2) no EMT markers or factors can represent universally epithelial and mesenchymal states, and thus (3) EMT cannot be assessed on the basis of one or a few EMT markers. In contrast to definition and proposed roles of EMT, loss of epithelial feature does not cause mesenchymal phenotype, and EMT does not contribute to embryonic mesenchyme and neural crest formation, the key developmental events from which the EMT concept was derived. EMT and MET, represented by change in cell shapes or adhesiveness, or symbolized by EMT factors, are biased interpretation of the overall change in cellular property and regulatory networks during development and cancer progression. Moreover, EMT and MET are consequences rather than driving factors of developmental and pathological processes. The true meaning of EMT in some developmental and pathological processes, such as fibrosis, needs re-evaluation. EMT is believed to endow malignant features, such as migration, stemness, etc., to cancer cells. However, the core property of cancer (tumorigenic) cells is neural stemness, and the core EMT factors are components of the regulatory networks of neural stemness. Thus, EMT in cancer progression is misattribution of the roles of neural stemness to the unknown mesenchymal state. Similarly, neural crest EMT is misattribution of intrinsic property of neural crest cells to the unknown mesenchymal state. Lack of basic rationale in EMT and related concepts urges re-evaluation of their significance as general rules for understanding developmental and pathological processes, and re-evaluation of their significance in scientific research.

Expression and pathogenesis of insulin-like growth factor-1 and insulin-like growth factor binding protein 3 in a mouse model of ulcerative colitis

Background and aim

Insulin-like growth factor-1 may be involved in the epithelial-to-mesenchymal transition process. It can mitigate adverse effects when interacting with insulin-like growth factor binding protein 3. This study aimed to explore alterations in the expression of these two factors in the colonic tissue of mice with ulcerative colitis.

Method

This study utilized animal models. Mice were randomly allocated into three distinct groups. Disease activity index assessment was performed first, followed by histological grading of colitis. Protein and mRNA expression levels were determined using Western blotting and RT-qPCR. Immunohistochemical detection was used to determine histochemistry scores. Pearson correlation and SPSS 25.0 software were used for data analysis.

Results

The findings indicated a reduction in the expression of the two investigated factors as well as in epithelial-to-mesenchymal transition epithelial markers during inflammation, while the expression of noninflammatory factors increased. These effects were notably amplified following treatment. Interestingly, the changes in epithelial-to-mesenchymal transition-inducing factors and mesenchymal markers contradicted this trend. Pearson correlation analysis revealed a correlation between molecular indicators of change and epithelial-to-mesenchymal transition.

Conclusion

Insulin-like growth factor-1 and insulin-like growth factor binding protein 3 may play a protective role in the development and progression of ulcerative colitis, potentially through their inhibition of the epithelial-to-mesenchymal transition. These factors hold promise as targets for the clinical diagnosis and treatment of ulcerative colitis.

Intermediate filaments at a glance

Intermediate filaments (IFs) comprise a large family of versatile cytoskeletal proteins, divided into six subtypes with tissue-specific expression patterns. IFs have a wide repertoire of cellular functions, including providing structural support to cells, as well as active roles in mechanical support and signaling pathways. Consequently, defects in IFs are associated with more than 100 diseases. In this Cell Science at a Glance article, we discuss the established classes of IFs and their general features, their functions beyond structural support, and recent advances in the field. We also highlight their involvement in disease and potential use as clinical markers of pathological conditions. Finally, we provide our view on current knowledge gaps and the future directions of the IF field.

XRCC2 driven homologous recombination subtypes and therapeutic targeting in lung adenocarcinoma metastasis

Lung adenocarcinoma (LUAD) is a leading cause of cancer mortality, with many patients facing poor prognosis, particularly those with metastatic or drug-resistant tumors. Homologous recombination genes (HRGs) are crucial in tumor progression and therapy resistance, but their clinical significance in LUAD is not well understood. In this study, we systematically characterize key HRGs in LUAD patients, identifying two distinct HR subtypes associated with different outcomes and biological functions. We establish a 5-gene scoring system (XRCC2, RAD51, BRCA1, FANCA, and CHEK1) that reliably predicts patient outcomes and immunotherapy responses in LUAD. Bioinformatics analysis and clinical validation highlight XRCC2 as a crucial biomarker in LUAD. Functional investigations through in vivo and in vitro experiments reveal the role of XRCC2 in promoting lung cancer migration and invasion. Mechanistically, XRCC2 stabilizes vimentin (VIM) protein expression through deubiquitylation. We predict c-MYC as a potential regulator of XRCC2 and demonstrate that inhibiting c-MYC with compound 10058-F4 reduces XRCC2 and VIM expression. Preclinical studies show the synergistic inhibition of metastasis in vivo when combining 10058-F4 with doxorubicin (Dox). Our findings present a potential personalized predictive tool for LUAD prognosis, identifying XRCC2 as a critical biomarker. The c-Myc-XRCC2-VIM axis emerges as a promising therapeutic target for overcoming lung metastasis. This study provides valuable insights into LUAD, proposing a prognostic tool for further clinical validation and unveiling a potential therapeutic strategy for combating lung metastasis by targeting c-Myc-XRCC2-VIM.

Epithelial-mesenchymal transition associated markers in sarcomatoid transformation of clear cell renal cell carcinoma

Epithelial-mesenchymal transition (EMT) plays a pivotal role in the development and progression of many cancers. Partial EMT (pEMT) could represent a critical step in tumor migration and dissemination. Sarcomatoid renal cell carcinoma (sRCC) is an aggressive form of renal cell carcinoma (RCC) composed of a carcinomatous (sRCC-Ca) and sarcomatous (sRCC-Sa) component. The role of (p)EMT in the progression of RCC to sRCC remains unclear. The aim of this study was to investigate the involvement of (p)EMT in RCC and sRCC. Tissue samples from 10 patients with clear cell RCC (ccRCC) and 10 patients with sRCC were selected. The expression of main EMT markers (miR-200 family, miR-205, SNAI1/2, TWIST1/2, ZEB1/2, CDH1/2, VIM) was analyzed by qPCR in ccRCC, sRCC-Ca, and sRCC-Sa and compared to non-neoplastic tissue and between both groups. Expression of E-cadherin, N-cadherin, vimentin and ZEB2 was analyzed using immunohistochemistry. miR-200c was downregulated in sRCC-Ca compared to ccRCC, while miR-200a was downregulated in sRCC-Sa compared to ccRCC. CDH1 was downregulated in sRCC-Sa when compared to any other group. ZEB2 was downregulated in ccRCC and sRCC compared to corresponding non-neoplastic kidney. A positive correlation was observed between CDH1 expression and miR-200a/b/c. Our results suggest that full EMT is not present in sRCC. Instead, discreet molecular differences exist between ccRCC, sRCC-Ca, and sRCC-Sa, possibly representing distinct intermediary states undergoing pEMT.

Susceptibility of primary ovine dorsal soft palate and palatine tonsil cells to FMDV infection

Foot and mouth disease (FMD) is a highly contagious viral disease affecting cloven-hoofed animals. This disease is one of the most important in animal health due to its significant socio-economic impact, especially in case of an outbreak. One important challenge associated with this disease is the ability of the FMD virus (FMDV) to persist in its hosts through still unresolved underlying mechanisms. The absence of relevant in vitro models is one factor preventing advancement in our understanding of FMDV persistence. While a primary bovine cell model has been established using cells from FMDV primary and persistence site in cattle, it appeared interesting to develop a similar model based on ovine anatomical sites of interest to compare host-pathogen interactions. Thus, epithelial cells derived from the palatine tonsils and the dorsal soft palate were isolated and cultured. Their epithelial nature was confirmed using immunofluorescence. Following monolayer infection with FMDV O/FRA/1/2001 Clone 2.2, the FMDV-sensitivity of these cells was evaluated. Dorsal soft palate (DSP) cells were also expanded in multilayers at the air-liquid interface to mimic a stratified epithelium sensitive to FMDV infection. Our investigation revealed the presence of infectious virus, as well as viral antigens and viral RNA, up to 35 days after infection of the cell multilayers. Further experiment with DSP cells from different individuals needs to be reproduced to confirm the robustness of the new model of persistence in multilayer DSP. The establishment of such primary cells creates new opportunities for FMDV research and analysis in sheep cells.

Bta-miR-200a Regulates Milk Fat Biosynthesis by Targeting IRS2 to Inhibit the PI3K/Akt Signal Pathway in Bovine Mammary Epithelial Cells

Milk fat synthesis has garnered significant attention due to its influence on the quality of milk. Recently, an increasing amount of proofs have elucidated that microRNAs (miRNAs) are important post-transcriptional factor involved in regulating gene expression and play a significant role in milk fat synthesis. MiR-200a was differentially expressed in the mammary gland tissue of dairy cows during different lactation periods, which indicated that miR-200a was a candidate miRNA involved in regulating milk fat synthesis. In our research, we investigated the potential function of miR-200a in regulating milk fat biosynthesis in bovine mammary epithelial cells (BMECs). We discovered that miR-200a inhibited cellular triacylglycerol (TAG) synthesis and suppressed lipid droplet formation; at the same time, miR-200a overexpression suppressed the mRNA and protein expression of milk fat metabolism-related genes, such as fatty acid synthase (FASN), peroxisome proliferator-activated receptor gamma (PPARγ), sterol regulatory element-binding protein 1 (SREBP1), CCAAT enhancer binding protein alpha (CEBPα), etc. However, knocking down miR-200a displayed the opposite results. We uncovered that insulin receptor substrate 2 (IRS2) was a candidate target gene of miR-200a through the bioinformatics online program TargetScan. Subsequently, it was confirmed that miR-200a directly targeted the 3'-untranslated region (3'-UTR) of IRS2 via real-time fluorescence quantitative PCR (RT-qPCR), western blot analysis, and dual-luciferase reporter gene assay. Additionally, IRS2 knockdown in BMECs has similar effects to miR-200a overexpression. Our research set up the mechanism by which miR-200a interacted with IRS2 and discovered that miR-200a targeted IRS2 and modulated the activity of the PI3K/Akt signaling pathway, thereby taking part in regulating milk fat synthesis in BMECs. Our research results provided valuable information on the molecular mechanisms for enhancing milk quality from the view of miRNA-mRNA regulatory networks.

Hypersensitivity of the vimentin cytoskeleton to net-charge states and Coulomb repulsion

As with most intermediate filament systems, the hierarchical self-assembly of vimentin into nonpolar filaments requires no nucleators or energy input. Utilizing a set of live-cell, single-molecule, and super-resolution microscopy tools, here we show that in mammalian cells, the assembly and disassembly of the vimentin cytoskeleton is highly sensitive to the protein net charge state. Starting with the intriguing observation that the vimentin cytoskeleton fully disassembles under hypotonic stress yet reassembles within seconds upon osmotic pressure recovery, we pinpoint ionic strength as its underlying driving factor. Further modulating the pH and expressing differently charged constructs, we converge on a model in which the vimentin cytoskeleton is destabilized by Coulomb repulsion when its mass-accumulated negative charges (-18 per vimentin protein) along the filament are less screened or otherwise intensified, and stabilized when the charges are better screened or otherwise reduced. Generalizing this model to other intermediate filaments, we further show that whereas the negatively charged GFAP cytoskeleton is similarly subject to fast disassembly under hypotonic stress, the cytokeratin, as a copolymer of negatively and positively charged subunits, does not exhibit this behavior. Thus, in cells containing both vimentin and keratin cytoskeletons, hypotonic stress disassembles the former but not the latter. Together, our results both provide new handles for modulating cell behavior and call for new attention to the effects of net charges in intracellular protein interactions.

Silencing CK19 regulates ferroptosis by affecting the expression of GPX4 and ACSL4 in oral squamous cell carcinoma in vivo and in vitro

To analyze the mechanism of how interfering with the cytokeratin 19 (CK19) pathway via the ferroptosis pathway affects tumor biological behaviors in the process of oral squamous cell carcinoma (OSCC) development. TCGA was used to analyze the expression of CK19 in pan-cancer and head and neck squamous cell carcinoma (HNSC) and to explore the ferroptosis-related genes related to HNSC. The effect of silencing CK19 on the migration ability of HSC-4 cells was verified by wound healing and migration assay. HSC-4 cells with silencing of CK19 and tumor-bearing nude mouse model were constructed. RT-qPCR, immunofluorescence and western blot were used to analyze the expression of ferroptosis-related genes. CK19 is highly expressed in human OSCC and nude mice. The migration ability of cells in the CK19-silenced group was lower than that of the control group. In vivo and in vitro, CK19 was negatively correlated with the expression of ACSL4 and positively correlated with the expression of GPX4. Compared with the control group, GPX4 expression was down-regulated and ACSL4 expression was up-regulated in the CK19-silenced group. Silencing CK19 also increased intracellular Fe2+ content and MDA content. Silencing CK19 can affect the expression of GPX4 and ACSL4 to regulate ferroptosis and at the same time increase the content of MDA, Fe2+ and ROS levels, thereby activating the regulation of ferroptosis pathway in the development of OSCC.

Applications of Biosensors in Bladder Cancer

Bladder cancer (BC) is the tenth most common cancer globally, predominantly affecting men. Early detection and treatment are crucial due to high recurrence rates and poor prognosis for advanced stages. Traditional diagnostic methods like cystoscopy and imaging have limitations, leading to the exploration of noninvasive methods such as liquid biopsy. This review highlights the application of biosensors in BC, including electrochemical and optical sensors for detecting tumor markers like proteins, nucleic acids, and other biomolecules, noting their clinical relevance. Emerging therapeutic approaches, such as antibody-drug conjugates, targeted therapy, immunotherapy, and gene therapy, are also explored, the role of biosensors in detecting corresponding biomarkers to guide these treatments is examined. Finally, the review addresses the current challenges and future directions for biosensor applications in BC, highlighting the need for large-scale clinical trials and the integration of advanced technologies like deep learning to enhance diagnostic accuracy and treatment efficacy.

Intestinal microbiota imbalance resulted by anti-Toxoplasma gondii immune responses aggravate gut and brain injury

BACKGROUND

Toxoplasma gondii infection affects a significant portion of the global population, leading to severe toxoplasmosis and, in immunocompromised patients, even death. During T. gondii infection, disruption of gut microbiota further exacerbates the damage to intestinal and brain barriers. Therefore, identifying imbalanced probiotics during infection and restoring their equilibrium can regulate the balance of gut microbiota metabolites, thereby alleviating tissue damage.

METHODS

Vimentin gene knockout (vim-/-) mice were employed as an immunocompromised model to evaluate the influence of host immune responses on gut microbiota balance during T. gondii infection. Behavioral experiments were performed to assess changes in cognitive levels and depressive tendencies between chronically infected vim-/- and wild-type (WT) mice. Fecal samples were subjected to 16S ribosomal RNA (rRNA) sequencing, and serum metabolites were analyzed to identify potential gut probiotics and their metabolites for the treatment of T. gondii infection.

RESULTS

Compared to the immunocompetent WT sv129 mice, the immunocompromised mice exhibited lower levels of neuronal apoptosis and fewer neurobehavioral abnormalities during chronic infection. 16S rRNA sequencing revealed a significant decrease in the abundance of probiotics, including several species of Lactobacillus, in WT mice. Restoring this balance through the administration of Lactobacillus murinus and Lactobacillus gasseri significantly suppressed the T. gondii burden in the intestine, liver, and brain. Moreover, transplantation of these two Lactobacillus spp. significantly improved intestinal barrier damage and alleviated inflammation and neuronal apoptosis in the central nervous system. Metabolite detection studies revealed that the levels of various Lactobacillus-related metabolites, including indole-3-lactic acid (ILA) in serum, decreased significantly after T. gondii infection. We confirmed that L. gasseri secreted much more ILA than L. murinus. Notably, ILA can activate the aromatic hydrocarbon receptor signaling pathway in intestinal epithelial cells, promoting the activation of CD8+ T cells and the secretion of interferon-gamma.

CONCLUSION

Our study revealed that host immune responses against T. gondii infection severely disrupted the balance of gut microbiota, resulting in intestinal and brain damage. Lactobacillus spp. play a crucial role in immune regulation, and the metabolite ILA is a promising therapeutic compound for efficient and safe treatment of T. gondii infection.

The expression of intermediate filaments in the abomasum of ruminants: A comparative study

Intermediate filaments (IFs) are key molecular factors of the cell and have been reported to play an important role in maintaining the structural integrity and functionality of the abomasum. This study was designed to determine the regional distribution, cellular localization and expression of several IFs, including CK8, CK18, CK19, vimentin, desmin, peripherin and nestin, as well as the connective tissue component laminin, in the bovine, ovine and caprine abomasa. Immunohistochemical analyses demonstrated varying levels of expression of CK8, CK18, CK19, vimentin, desmin, nestin, peripherin and laminin in the bovine, ovine and caprine abomasa. CK8 immunoreactions were particularly evident in the luminal and glandular epithelia of the glands found in the abomasal cardia, fundus and pylorus in all three species. In the bovine abomasum, CK18 immunoreactions were stronger in the parietal cells, compared to the chief cells. In the abomasum of all three species, the smooth muscle as well as the smooth muscle cells of the vascular media in the cardiac, fundic and pyloric regions showed strong immunoreactivity. In all three species, the cardiac, fundic and pyloric regions of the abomasum showed strong peripherin and nestin immunoreactions in the luminal and glandular epithelial cells, stromal and smooth muscle cells, nervous plexuses and blood vessels. The expression patterns of IFs and laminin in the ruminant abomasum suggest that these proteins play a structural role in the cytoskeleton and are effective in maintaining abomasal tissue integrity and stability.

Development and dysfunction of structural cells in eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a disorder characterized by dysfunction and chronic local inflammation of the esophagus. The incidence and prevalence of EoE are increasing worldwide. The mechanisms responsible are poorly understood, and effective treatment options are limited. From the lumen outward, the esophagus comprises stratified squamous epithelium, lamina propria, and muscle. The tissue-specific nature of EoE strongly suggests that structural cells in the esophagus are involved in the EoE diathesis. Epithelial basal cell hyperplasia and dilated intercellular spaces are cardinal features of EoE. Some patients with EoE develop lamina propria fibrosis, strictures, or esophageal muscle dysmotility. Clinical symptoms of EoE are only weakly correlated with peak eosinophil count, implying that other cell types contribute to EoE pathogenesis. Epithelial, endothelial, muscle, and fibroblast cells can each initiate inflammation and repair, regulate tissue resident immune cells, recruit peripheral leukocytes, and tailor adaptive immune cell responses. A better understanding of how structural cells maintain tissue homeostasis, respond to cell-intrinsic and cell-extrinsic stressors, and exacerbate and/or resolve inflammatory responses in the esophagus is needed. This knowledge will facilitate the development of more efficacious treatment strategies for EoE that can restore homeostasis of both hematopoietic and structural elements in the esophagus.

Proteomics-based identification of biomarkers reflecting endogenous and exogenous exposure to the advanced glycation end product precursor methylglyoxal in SH-SY5Y human neuroblastoma cells

Methylglyoxal (MGO), a highly reactive precursor of advanced glycation end products, is endogenously produced and prevalent in various food products. This study aimed to characterize protein modifications in SH-SY5Y human neuroblastoma cells induced by MGO and identify potential biomarkers for its exposure and toxicity. A shot-gun proteomic analysis was applied to characterize protein modifications in cells incubated with and without exogenous MGO. Seventy-seven proteins were identified as highly susceptible to MGO modification, among which eight, including vimentin and histone H2B type 2-F, showing concentration-dependent modifications by externally added MGO, were defined as biomarkers for exogenous MGO exposure. Remarkably, up to 10 modification sites were identified on vimentin. Myosin light polypeptide 6 emerged as a biomarker for MGO toxicity, with modifications exclusively observed under cytotoxic MGO levels. Additionally, proteins like serine/threonine-protein kinase SIK2 and calcyphosin, exhibiting comparable or even higher modification levels in control compared to exogenous MGO-treated cells, were defined as biomarkers for endogenous exposure. Bioinformatics analysis revealed that motor proteins, cytoskeleton components, and glycolysis proteins were overrepresented among those highly susceptible to MGO modification. These results identify biomarkers for both endogenous and exogenous MGO exposure and provide insights into the cellular effects of endogenously formed versus externally added MGO.

Generation and application of immortalized sheep fetal fibroblast cell line

BACKGROUND

Primary sheep fetal fibroblasts (SFFCs) have emerged as a valuable resource for investigating the molecular and pathogenic mechanisms of orf viruses (ORFV). However, their utilization is considerably restricted due to the exorbitant expenses associated with their isolation and culture, their abbreviated lifespan, and the laborious procedure.

RESULTS

In our investigation, the primary SFFCs were obtained and immortalized by introducing a lentiviral recombinant plasmid containing the large T antigen from simian virus 40 (SV40). The expression of fibronectin and vimentin proteins, activity of SV40 large T antigen, cell proliferation assays, and analysis of programmed cell death revealed that the immortalized large T antigen SFFCs (TSFFCs) maintained the same physiological characteristics and biological functions as the primary SFFCs. Moreover, TSFFCs demonstrated robust resistance to apoptosis, extended lifespan, and enhanced proliferative activity compared to primary SFFCs. Notably, the primary SFFCs did not undergo in vitro transformation or exhibit any indications of malignancy in nude mice. Furthermore, the immortalized TSFFCs displayed live ORFV vaccine susceptibility.

CONCLUSIONS

Immortalized TSFFCs present valuable in vitro models for exploring the characteristics of ORFV using various techniques. This indicates their potential for secure utilization in future studies involving virus isolation, vaccine development, and drug screening.

Cytoskeletal crosstalk: A focus on intermediate filaments

The cytoskeleton, comprising actin microfilaments, microtubules, and intermediate filaments, is crucial for cell motility and tissue integrity. While prior studies largely focused on individual cytoskeletal networks, recent research underscores the interconnected nature of these systems in fundamental cellular functions like adhesion, migration, and division. Understanding the coordination of these distinct networks in both time and space is essential. This review synthesizes current findings on the intricate interplay between these networks, emphasizing the pivotal role of intermediate filaments. Notably, these filaments engage in extensive crosstalk with microfilaments and microtubules through direct molecular interactions, cytoskeletal linkers, and molecular motors that form molecular bridges, as well as via more complex regulation of intracellular signaling.

Evidence of promoting effects of 6:2 Cl-PFESA on hepatocellular carcinoma proliferation in humans: An ideal alternative for PFOS in terms of environmental health?

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are synthetic chemicals, encompassing compounds like perfluorooctane sulfonate (PFOS), which have widespread applications across various industries, including food packaging and firefighting. In recent years, China has increasingly employed 6:2 Cl-PFESA as an alternative to PFOS. Although the association between PFAS exposure and hepatocellular carcinoma (HCC) has been demonstrated, the underlying mechanisms that promote HCC proliferation are uncleared. Therefore, we aimed to investigate the effects and differences of PFOS and 6:2 Cl-PFESA on HCC proliferation through in vivo and in vitro tumor models. Our results reveal that both PFOS and 6:2 Cl-PFESA significantly contribute to HCC proliferation in vitro and in vivo. Exposure led to reduced population doubling times, enlarged cell colony sizes, enhanced DNA synthesis efficiency, and a higher proportion of cells undergoing mitosis. Furthermore, both PFOS and 6:2 Cl-PFES) have been shown to activate the PI3K/AKT/mTOR signaling pathway and inhibit necroptosis. This action consequently enhances the proliferation of HCC cells. Our phenotypic assay findings suggest that the tumorigenic potential of 6:2 Cl-PFESA surpasses that of PFOS; in a subcutaneous tumor model using nude mice, the mean tumor weight for the 6:2 Cl-PFESA-treated cohort was 2.33 times that observed in the PFOS cohort (p < 0.01). Despite 6:2 Cl-PFESA being considered a safer substitute for PFOS, the pronounced effects of this chemical on HCC cell growth warrant a thorough assessment of hepatotoxicity risks linked to its usage.

Gene-Expression Patterns of Tumor and Peritumor Tissues of Smoking and Non-Smoking HPV-Negative Patients with Head and Neck Squamous Cell Carcinoma

We studied the gene-expression patterns in specimens of tumor and peritumor tissue biopsies of 26 patients with head and neck carcinomas depending on smoking status. Histological and immunohistochemical examinations verified that all tumors belonged to the "classical" subgroup of head and neck carcinomas, and the HPV-negative tumor status was confirmed. The expression of 28 tumor-associated genes determined by RT-PCR was independent of patients' sex or age, TNM status, degree of differentiation, or tissue localization. Moreover, in peritumor tissue, none of the 28 genes were differentially expressed between the groups of smoking and nonsmoking patients. During oncotransformation in both studied groups, there were similar processes typical for HNSCC progression: the expression levels of paired keratins 4 and 13 were reduced, while the expression levels of keratin 17 and CD44 were significantly increased. However, further investigation revealed some distinctive features: the expression of the genes EGFR and TP63 increased significantly only in the nonsmoking group, and the expression of IL6, CDKN2A, EGF, and PITX1 genes changed only in the smoking group. In addition, correlation analysis identified several clusters within which genes displayed correlations in their expression levels. The largest group included 10 genes: TIMP1, TIMP2, WEE1, YAP, HIF1A, PI3KCA, UTP14A, APIP, PTEN, and SLC26A6. The genetic signatures associated with smoking habits that we have found may serve as a prerequisite for the development of diagnostic panels/tests predicting responses to different therapeutic strategies for HNSCC.