Role of cellular cytoskeleton in epithelial-mesenchymal transition process during cancer progression

Exposure to trichloromethane via drinking water promotes progression of colorectal cancer by activating IRE1α/XBP1 pathway of endoplasmic reticulum stress

Trichloromethane (TCM), a commonly recognized disinfection by-product formed during the chlorination of water, has been associated with the onset of colorectal cancer (CRC) in humans. Despite this, the impact of TCM on the progression of CRC remains uncertain. In this investigation, it was observed that exposure to TCM could augment the migratory capabilities of CRC cells and facilitate the advancement of colorectal tumors. To delve deeper into the mechanism responsible for TCM-induced CRC progression, we performed RNA-Seq analysis at cellular and animal levels after TCM exposure. Both the KEGG and GO enrichment analyses indicated the activation of endoplasmic reticulum stress (ERS) and the regulation of the cytoskeleton. Subsequently, we confirmed the activation of the IRE1α/XBP1 pathway of ERS through western blot and RT-qPCR. Additionally, we observed the aggregation of cytoskeletal proteins F-actin and β-tubulin at the cell membrane periphery and the development of cellular pseudopods using immunofluorescence following exposure to TCM in vitro. The downregulation of IRE1α and XBP1 through siRNA interference resulted in the disruption of cell cytoskeleton rearrangement and impaired cell migration capability. Conversely, treatment with TCM mitigated this inhibitory effect. Moreover, chronic exposure to low concentration of TCM also triggered CRC cell migration by causing cytoskeletal reorganization, a process controlled by the IRE1α/XBP1 axis. Our study concludes that TCM exposure induces cell migration through the activation of ERS, which in turn regulates cytoskeleton rearrangement. This study offers novel insights into the mechanism through which TCM facilitates the progression of CRC.

Direct and cell-mediated EV-ECM interplay

Extracellular vesicles (EV) are a heterogeneous group of lipid particles excreted by cells. They play an important role in regeneration, development, inflammation, and cancer progression, together with the extracellular matrix (ECM), which they constantly interact with. In this review, we discuss direct and indirect interactions of EVs and the ECM and their impact on different physiological processes. The ECM affects the secretion of EVs, and the properties of the ECM and EVs modulate EVs' diffusion and adhesion. On the other hand, EVs can affect the ECM both directly through enzymes and indirectly through the modulation of the ECM synthesis and remodeling by cells. This review emphasizes recently discovered types of EVs bound to the ECM and isolated by enzymatic digestion, including matrix-bound nanovesicles (MBV) and tissue-derived EV (TiEV). In addition to the experimental studies, computer models of the EV-ECM-cell interactions, from all-atom models to quantitative pharmacology models aiming to improve our understanding of the interaction mechanisms, are also considered. STATEMENT OF SIGNIFICANCE: Application of extracellular vesicles in tissue engineering is an actively developing area. Vesicles not only affect cells themselves but also interact with the matrix and change it. The matrix also influences both cells and vesicles. In this review, different possible types of interactions between vesicles, matrix, and cells are discussed. Furthermore, the united EV-ECM system and its regulation through the cellular activity are presented.

ESM1 facilitates the EGFR/HER3-triggered epithelial-to-mesenchymal transition and progression of gastric cancer via modulating interplay between Akt and angiopoietin-2 signaling

Gastric cancer (GC) poses global challenges due to its difficult early diagnosis and drug resistance, necessitating the identification of early detection markers and understanding of oncogenic pathways for effective GC therapy. Endothelial cell-specific molecule 1 (ESM1), a secreted glycoprotein, is elevated in various cancers, but its role in GC remains controversial. In our study, ESM1 was elevated in GC tissues, and its concentration was correlated with progression and poorer patient prognosis in independent cohorts. Functionally, ESM1 expression promoted proliferation, anoikis resistance, and motility of GC cells, as well as tumor growth in PDOs and in GC xenograft models. Mechanistically, ESM1 expression triggered the epithelial-to-mesenchymal transition (EMT) of GC cells by enhancing epidermal growth factor receptor (EGFR)/human EGFR 3 (HER3) association and activating the EGFR/HER3-Akt pathway. Additionally, angiopoietin-2 (ANGPT2) was found to be highly correlated with ESM1 and interplayed with Akt to induce the EMT and cancer progression. Use of a signal peptide deletion mutant (ESM1-19del) showed that the secreted form of ESM1 is crucial for its protumorigenic effects by activating the EGFR/HER3-Akt/ANGPT2 pathway to promote the EMT. Patients with high levels of both ESM1 and ANGPT2 had the poorest prognoses. Furthermore, therapeutic peptides successfully inhibited ESM1's induction of the aforementioned signals and motility of GC cells. ESM1's oncogenic role in GC involves activating the EGFR/HER3-Akt/ANGPT2 pathway, presenting a potential therapeutic target for GC.

Intersecting pathways: The role of hybrid E/M cells and circulating tumor cells in cancer metastasis and drug resistance

Cancer metastasis and therapy resistance are intricately linked with the dynamics of Epithelial-Mesenchymal Transition (EMT) and Circulating Tumor Cells (CTCs). EMT hybrid cells, characterized by a blend of epithelial and mesenchymal traits, have emerged as pivotal in metastasis and demonstrate remarkable plasticity, enabling transitions across cellular states crucial for intravasation, survival in circulation, and extravasation at distal sites. Concurrently, CTCs, which are detached from primary tumors and travel through the bloodstream, are crucial as potential biomarkers for cancer prognosis and therapeutic response. There is a significant interplay between EMT hybrid cells and CTCs, revealing a complex, bidirectional relationship that significantly influences metastatic progression and has a critical role in cancer drug resistance. This resistance is further influenced by the tumor microenvironment, with factors such as tumor-associated macrophages, cancer-associated fibroblasts, and hypoxic conditions driving EMT and contributing to therapeutic resistance. It is important to understand the molecular mechanisms of EMT, characteristics of EMT hybrid cells and CTCs, and their roles in both metastasis and drug resistance. This comprehensive understanding sheds light on the complexities of cancer metastasis and opens avenues for novel diagnostic approaches and targeted therapies and has significant advancements in combating cancer metastasis and overcoming drug resistance.

Asymmetric crowders and membrane morphology at the nexus of intracellular trafficking and oncology

A definitive understanding of the interplay between protein binding/migration and membrane curvature evolution is emerging but needs further study. The mechanisms defining such phenomena are critical to intracellular transport and trafficking of proteins. Among trafficking modalities, exosomes have drawn attention in cancer research as these nano-sized naturally occurring vehicles are implicated in intercellular communication in the tumor microenvironment, suppressing anti-tumor immunity and preparing the metastatic niche for progression. A significant question in the field is how the release and composition of tumor exosomes are regulated. In this perspective article, we explore how physical factors such as geometry and tissue mechanics regulate cell cortical tension to influence exosome production by co-opting the biophysics as well as the signaling dynamics of intracellular trafficking pathways and how these exosomes contribute to the suppression of anti-tumor immunity and promote metastasis. We describe a multiscale modeling approach whose impact goes beyond the fundamental investigation of specific cellular processes toward actual clinical translation. Exosomal mechanisms are critical to developing and approving liquid biopsy technologies, poised to transform future non-invasive, longitudinal profiling of evolving tumors and resistance to cancer therapies to bring us one step closer to the promise of personalized medicine.

The concerted action of SEPT9 and EPLIN modulates the adhesion and migration of human fibroblasts

Septins are cytoskeletal proteins that participate in cell adhesion, migration, and polarity establishment. The septin subunit SEPT9 directly interacts with the single LIM domain of epithelial protein lost in neoplasm (EPLIN), an actin-bundling protein. Using a human SEPT9 KO fibroblast cell line, we show that cell adhesion and migration are regulated by the interplay between both proteins. The low motility of SEPT9-depleted cells could be partly rescued by increased levels of EPLIN. The normal organization of actin-related filopodia and stress fibers was directly dependent on the expression level of SEPT9 and EPLIN. Increased levels of SEPT9 and EPLIN enhanced the size of focal adhesions in cell protrusions, correlating with stabilization of actin bundles. Conversely, decreased levels had the opposite effect. Our work thus establishes the interaction between SEPT9 and EPLIN as an important link between the septin and the actin cytoskeleton, influencing cell adhesion, motility, and migration.

Emerging paradigms in cancer cell plasticity

Cancer cells metastasize to distant organs by altering their characteristics within the tumor microenvironment (TME) to effectively overcome challenges during the multistep tumorigenesis. Plasticity endows cancer cell with the capacity to shift between different morphological states to invade, disseminate, and seed metastasis. The epithelial-to-mesenchymal transition (EMT) is a theory derived from tissue biopsy, which explains the acquisition of EMT transcription factors (TFs) that convey mesenchymal features during cancer migration and invasion. On the other hand, adherent-to-suspension transition (AST) is an emerging theory derived from liquid biopsy, which describes the acquisition of hematopoietic features by AST-TFs that reprograms anchorage dependency during the dissemination of circulating tumor cells (CTCs). The induction and plasticity of EMT and AST dynamically reprogram cell-cell interaction and cell-matrix interaction during cancer dissemination and colonization. Here, we review the mechanisms governing cellular plasticity of AST and EMT during the metastatic cascade and discuss therapeutic challenges posed by these two morphological adaptations to provide insights for establishing new therapeutic interventions. [BMB Reports 2024; 57(6): 273-280].

An AFM-Based Model-Fitting-Free Viscoelasticity Characterization Method for Accurate Grading of Primary Prostate Tumor

Viscoelasticity is a crucial property of cells, which plays an important role in label-free cell characterization. This paper reports a model-fitting-free viscoelasticity calculation method, correcting the effects of frequency, surface adhesion and liquid resistance on AFM force-distance (FD) curves. As demonstrated by quantifying the viscosity and elastic modulus of PC-3 cells, this method shows high self-consistency and little dependence on experimental parameters such as loading frequency, and loading mode (Force-volume vs. PeakForce Tapping). The rapid calculating speed of less than 1ms per curve without the need for a model fitting process is another advantage. Furthermore, this method was utilized to characterize the viscoelastic properties of primary clinical prostate cells from 38 patients. The results demonstrate that the reported characterization method a comparable performance with the Gleason Score system in grading prostate cancer cells, This method achieves a high average accuracy of 97.6% in distinguishing low-risk prostate tumors (BPH and GS6) from higher-risk (GS7-GS10) prostate tumors and a high average accuracy of 93.3% in distinguishing BPH from prostate cancer.

Transcription Factors and Markers Related to Epithelial-Mesenchymal Transition and Their Role in Resistance to Therapies in Head and Neck Cancers

Head and neck cancers (HNCs) are heterogeneous and aggressive tumors of the upper aerodigestive tract. Although various histological types exist, the most common is squamous cell carcinoma (HNSCC). The incidence of HNSCC is increasing, making it an important public health concern. Tumor resistance to contemporary treatments, namely, chemo- and radiotherapy, and the recurrence of the primary tumor after its surgical removal cause huge problems for patients. Despite recent improvements in these treatments, the 5-year survival rate is still relatively low. HNSCCs may develop local lymph node metastases and, in the most advanced cases, also distant metastases. A key process associated with tumor progression and metastasis is epithelial-mesenchymal transition (EMT), when poorly motile epithelial tumor cells acquire motile mesenchymal characteristics. These transition cells can invade different adjacent tissues and finally form metastases. EMT is governed by various transcription factors, including the best-characterized TWIST1 and TWIST2, SNAIL, SLUG, ZEB1, and ZEB2. Here, we highlight the current knowledge of the process of EMT in HNSCC and present the main protein markers associated with it. This review focuses on the transcription factors related to EMT and emphasizes their role in the resistance of HNSCC to current chemo- and radiotherapies. Understanding the role of EMT and the precise molecular mechanisms involved in this process may help with the development of novel anti-cancer therapies for this type of tumor.

ARAP1 negatively regulates stress fibers formation and metastasis in lung adenocarcinoma via controlling Rho signaling

Small GTPases regulate multiple important cellular behaviors and their activities are strictly controlled by a mass of regulators. The dysfunction or abnormal expression of small GTPases or their regulators was frequently observed in various cancers. Here, we analyzed the expression and prognostic correlation of several GTPases and related regulators based on the TCGA database and found that Ankyrin Repeat and PH Domain 1 (ARAP1), a GTPase activating protein (GAP), is reduced in lung adenocarcinoma tissues compared to normal tissues and displays a positive correlation with overall survival (OS) and progression-free survival (PFS) of patients with lung adenocarcinoma. qPCR and western blot verified that ARAP1 is frequently downregulated in lung adenocarcinoma tumor tissues and cancer cells, and its downregulation might be mediated by epigenetic modification. Moreover, metastatic assays showed that overexpression of ARAP1 significantly inhibits metastasis of lung adenocarcinoma in vitro and in vivo. We further demonstrated that Rho signaling inhibition, mediated by RhoGAP activity of ARAP1, majorly contributes to suppressing migration and invasion of lung adenocarcinoma cancer cells via inhibiting stress fibers formation. In summary, this study indicates that ARAP1 may serve as a potential prognostic predictor and a metastatic suppressor in lung adenocarcinoma via its RhoGAP activity.

Differential response of MDA‑MB‑231 breast cancer and MCF10A normal breast cells to cytoskeletal disruption

Metastasis remains a major clinical problem in cancer diagnosis and treatment. Metastasis is the leading cause of cancer‑related mortality but is still poorly understood. Cytoskeletal proteins are considered potential therapeutic targets for metastatic cancer cells because the cytoskeleton serves a key role in the migration and invasion of these cells. Vimentin and F‑actin exhibit several functional similarities and undergo quantitative and structural changes during carcinogenesis. The present study investigated the effects of vimentin and F‑actin deficiency on the survival and motility of breast cancer cells. In metastatic breast cancer cells (MDA‑MB‑231) and breast epithelial cells (MCF10A), vimentin was knocked down by small interfering RNA and F‑actin was depolymerized by latrunculin A, respectively. The effect of reduced vimentin and F‑actin content on cell viability was analyzed using the MTT assay and the proliferative capacity was compared by analyzing the recovery rate. The effect on motility was analyzed based on two processes: The distance traveled by tracking the cell nucleus and the movement of the protrusions. The effects on cell elasticity were measured using atomic force microscopy. Separately reducing vimentin or F‑actin did not effectively inhibit the growth and motility of MDA‑MB‑231 cells; however, when both vimentin and F‑actin were simultaneously deficient, MDA‑MB‑231 cells growth and migration were severely impaired. Vimentin deficiency in MDA‑MB‑231 cells was compensated by an increase in F‑actin polymerization, but no complementary action of vimentin on the decrease in F‑actin was observed. In MCF10A cells, no complementary interaction was observed for both vimentin and F‑actin.

NF-κB signaling in neoplastic transition from epithelial to mesenchymal phenotype

NF-κB transcription factors are critical regulators of innate and adaptive immunity and major mediators of inflammatory signaling. The NF-κB signaling is dysregulated in a significant number of cancers and drives malignant transformation through maintenance of constitutive pro-survival signaling and downregulation of apoptosis. Overactive NF-κB signaling results in overexpression of pro-inflammatory cytokines, chemokines and/or growth factors leading to accumulation of proliferative signals together with activation of innate and select adaptive immune cells. This state of chronic inflammation is now thought to be linked to induction of malignant transformation, angiogenesis, metastasis, subversion of adaptive immunity, and therapy resistance. Moreover, accumulating evidence indicates the involvement of NF-κB signaling in induction and maintenance of invasive phenotypes linked to epithelial to mesenchymal transition (EMT) and metastasis. In this review we summarize reported links of NF-κB signaling to sequential steps of transition from epithelial to mesenchymal phenotypes. Understanding the involvement of NF-κB in EMT regulation may contribute to formulating optimized therapeutic strategies in cancer. Video Abstract.

EMT induces characteristic changes of Rho GTPases and downstream effectors with a mitosis-specific twist

Epithelial-mesenchymal transition (EMT) is a key cellular transformation for many physiological and pathological processes ranging from cancer over wound healing to embryogenesis. Changes in cell migration, cell morphology and cellular contractility were identified as hallmarks of EMT. These cellular properties are known to be tightly regulated by the actin cytoskeleton. EMT-induced changes of actin-cytoskeletal regulation were demonstrated by previous reports of changes of actin cortex mechanics in conjunction with modifications of cortex-associated f-actin and myosin. However, at the current state, the changes of upstream actomyosin signaling that lead to corresponding mechanical and compositional changes of the cortex are not well understood. In this work, we show in breast epithelial cancer cells MCF-7 that EMT results in characteristic changes of the cortical association of Rho-GTPases Rac1, RhoA and RhoC and downstream actin regulators cofilin, mDia1 and Arp2/3. In the light of our findings, we propose that EMT-induced changes in cortical mechanics rely on two hitherto unappreciated signaling paths-i) an interaction between Rac1 and RhoC and ii) an inhibitory effect of Arp2/3 activity on cortical association of myosin II.

Prognostic Nomogram for Lymph-Node Metastasis in Oral Squamous Cell Carcinoma (OSCC) Using Immunohistochemical Marker D2-40

Introduction

Nomograms are proven in "individualized risk prediction" in sarcomas and breast and prostate cancers. Incorporating immunohistochemical markers and histopathological parameters can enhance accuracy of these graphical representations of statistical predictive models concerning metastasis. D2-40, a monoclonal antibody to podoplanin (regulator of motility expressed in malignant epithelial cells), dually predicts metastatic potential of tumour by estimating the motile tumour phenotype and by detecting lymphatic vessels/density, both essential to metastasis in OSCC. Thus, we propose a model that incorporates D2-40 immunostaining of individual tumour cells (ITC) too with other variables (seen in H+E staining) as a predictive nomogram.

Methods

Sixty cases of OSCC were selected with equal number of cases (n=30) of pN0 and pN+ status. Bryne's grading of invasive front of tumour (ITF) was done on H+E-stained slides followed by D2-40 immunostaining for ITCs at ITF and lymphatic vessels. Multivariate regression analysis was used to generate the nomogram of LNM where the predictive contribution of each covariate, namely depth of invasion, D2-40-stained ITCs, gender, histological grade, and worst pattern of invasion (WPOI), was plotted on a scale of 1-100 points.

Results

The nomogram showed that the strongest variable in OSCC was the WPOI in H+E-stained section followed by D2-40-positive ITCs and gender.

Discussion

Our predictive nomogram for LNM in OSCC surprisingly showed that a tumour with lower score of WPOI (islands vs ITC) showed numerous D2-40-positive ITCs, drastically increasing the probability of metastasis. The concept of "individualized risk prediction" can be used to predict lymph node metastasis using a variety of histopathological criteria that can be visualized in routine and immunohistochemical staining in OSCC with the aid of a nomogram.

Spatial Heterogeneity in Cytoskeletal Mechanics Response to TGF-β1 and Hypoxia Mediates Partial Epithelial-to-Meshenchymal Transition in Epithelial Ovarian Cancer Cells

Metastatic progression of epithelial ovarian cancer (EOC) involves the partial epithelial-to-mesenchymal transition (EMT) of cancer cells in the primary tumor and dissemination into peritoneal fluid. In part to the high degree of heterogeneity in EOC cells, the identification of EMT in highly epithelial cells in response to differences in matrix mechanics, growth factor signaling, and tissue hypoxia is very difficult. We analyzed different degrees of EMT by tracking changes in cell and nuclear morphology, along with the organization of cytoskeletal proteins. In our analysis, we see a small percentage of individual cells that show dramatic response to TGF-β1 and hypoxia treatment. We demonstrate that EOC cells are spatially aware of their surroundings, with a subpopulation of EOC cells at the periphery of a cell cluster in 2D environments exhibited a greater degree of EMT. These peripheral cancer cells underwent partial EMT, displaying a hybrid of mesenchymal and epithelial characteristics, which often included less cortical actin and more perinuclear cytokeratin expression. Collectively, these data show that tumor-promoting microenvironment conditions can mediate invasive cell behavior in a spatially regulated context in a small subpopulation of highly epithelial clustered cancer cells that maintain epithelial characteristics while also acquiring some mesenchymal traits through partial EMT.

High Level of GMFG Correlated to Poor Clinical Outcome and Promoted Cell Migration and Invasion through EMT Pathway in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) has a very poor prognosis due to the disease's lack of established targeted treatment options. Glia maturation factor γ (GMFG), a novel ADF/cofilin superfamily protein, has been reported to be differentially expressed in tumors, but its expression level in TNBC remains unknown. The question of whether GMFG correlates with the TNBC prognosis is also unclear. In this study, data from the Cancer Genome Atlas (TCGA), Clinical Proteomic Tumor Analysis Consortium (CPTAC), Human Protein Atlas (HPA), and Genotype-Tissue Expression (GTEx) databases were used to analyze the expression of GMFG in pan-cancer and the correlation between clinical factors. Gene Set Cancer Analysis (GSCA) and Gene Set Enrichment Analysis (GSEA) were also used to analyze the functional differences between the different expression levels and predict the downstream pathways. GMFG expression in breast cancer tissues, and its related biological functions, were further analyzed by immunohistochemistry (IHC), immunoblotting, RNAi, and function assay; we found that TNBC has a high expression of GMFG, and this higher expression was correlated with a poorer prognosis in TCGA and collected specimens of the TNBC. GMFG was also related to TNBC patients' clinicopathological data, especially those with histological grade and axillary lymph node metastasis. In vitro, GMFG siRNA inhibited cell migration and invasion through the EMT pathway. The above data indicate that high expression of GMFG in TNBC is related to malignancy and that GMFG could be a biomarker for the detection of TNBC metastasis.

Biomechanical and biochemical assessment of YB-1 expression in A375 melanoma cell line: Exploratory study

Malignant melanoma is the most lethal form of skin cancer. Y-box binding protein 1 (YB-1) plays a prominent role in mediating metastatic behavior by promoting epithelial-to-mesenchymal transition (EMT). Migratory melanoma cells exhibit two major migration modes: elongated mesenchymal or rounded amoeboid. Using A375 melanoma cell line and the YB-1 knock-out model, we aimed to elucidate biochemical and biomechanical changes in migration signaling pathways in the context of melanoma metastases. We subjected A375 YB-1 knock-out and parental cells to atomic force microscopy (stiffness determination), immunolabelling, and proteome analysis. We found that YB-1 expressing cells were significantly stiffer compared to the corresponding YB-1 knock-out cell line. Our study demonstrated that the constitutive expression of YB-1 in A375 melanoma cell line appears to be closely related to known biomarkers of epithelial-to-mesenchymal transition, nestin, and vimentin, resulting in a stiffer phenotype, as well as a wide array of proteins involved in RNA, ribosomes, and spliceosomes. YB-1 knock-out resulted in nestin depletion and significantly lower vimentin expression, as well as global upregulation of proteins related to the cytoskeleton and migration. YB-1 knock-out cells demonstrated both morphological features and biochemical drivers of mesenchymal/ameboid migration. Melanoma is a highly plastic, adaptable, and aggressive tumor entity, capable of exhibiting characteristics of different migratory modes.

Proteomics-Based Identification of Dysregulated Proteins and Biomarker Discovery in Invasive Ductal Carcinoma, the Most Common Breast Cancer Subtype

Invasive ductal carcinoma (IDC) is the most common histological subtype of malignant breast cancer (BC), and accounts for 70-80% of all invasive BCs. IDC demonstrates great heterogeneity in clinical and histopathological characteristics, prognoses, treatment strategies, gene expressions, and proteomic profiles. Significant proteomic determinants of the progression from intraductal pre-invasive malignant lesions of the breast, which characterize a ductal carcinoma in situ (DCIS), to IDC, are still poorly identified, validated, and clinically applied. In the era of "6P" medicine, it remains a great challenge to determine which patients should be over-treated versus which need to be actively monitored without aggressive treatment. The major difficulties for designating DCIS to IDC progression may be solved by understanding the integrated genomic, transcriptomic, and proteomic bases of invasion. In this review, we showed that multiple proteomics-based techniques, such as LC-MS/MS, MALDI-ToF MS, SELDI-ToF-MS, MALDI-ToF/ToF MS, MALDI-MSI or MasSpec Pen, applied to in-tissue, off-tissue, BC cell lines and liquid biopsies, improve the diagnosis of IDC, as well as its prognosis and treatment monitoring. Classic proteomics strategies that allow the identification of dysregulated protein expressions, biological processes, and interrelated pathway analyses based on aberrant protein-protein interaction (PPI) networks have been improved to perform non-invasive/minimally invasive biomarker detection of early-stage IDC. Thus, in modern surgical oncology, highly sensitive, rapid, and accurate MS-based detection has been coupled with "proteome point sampling" methods that allow for proteomic profiling by in vivo "proteome point characterization", or by minimal tissue removal, for ex vivo accurate differentiation and delimitation of IDC. For the detection of low-molecular-weight proteins and protein fragments in bodily fluids, LC-MS/MS and MALDI-MS techniques may be coupled to enrich and capture methods which allow for the identification of early-stage IDC protein biomarkers that were previously invisible for MS-based techniques. Moreover, the detection and characterization of protein isoforms, including posttranslational modifications of proteins (PTMs), is also essential to emphasize specific molecular mechanisms, and to assure the early-stage detection of IDC of the breast.

Dissolvable Self-Locking Microneedle Patches Integrated with Immunomodulators for Cancer Immunotherapy

Advancements in micro-resolution 3D printers have significantly facilitated the development of highly complex mass-producible drug delivery platforms. Conventionally, due to the limitations of micro-milling machineries, dissolvable microneedles (MNs) are mainly fabricated in cone-shaped geometry with limited drug delivery accuracy. Herein, to overcome the limitations of conventional MNs, a novel projection micro-stereolithography 3D printer-based self-locking MN for precise skin insertion, adhesion, and transcutaneous microdose drug delivery is presented. The geometry of self-locking MN consists of a sharp skin-penetrating tip, a wide skin interlocking body, and a narrow base with mechanical supports fabricated over a flexible hydrocolloid patch to improve the accuracy of skin penetration into irregular surfaces. Melanoma, a type of skin cancer, is selected as the model for the investigation of self-locking MNs due to its irregular and uneven surface. In vivo immunotherapy efficacy is evaluated by integrating SD-208, a novel transforming growth factor-β (TGF-β) inhibitor that suppresses the proliferation and metastasis of tumors, and anti-PD-L1 (aPD-L1 Ab), an immune checkpoint inhibitor that induces T cell-mediated tumor cell death, into self-locking MNs and comparing them with intratumoral injection. Evaluation of (aPD-L1 Ab)/SD-208 delivery effectiveness in B16F10 melanoma-bearing mice model confirms significantly improved dose efficacy of self-locking MNs compared with intratumoral injection.

The role of activated androgen receptor in cofilin phospho-regulation depends on the molecular subtype of TNBC cell line and actin assembly dynamics

Triple negative breast cancer (TNBC) is highly metastatic and of poor prognosis. Metastasis involves coordinated actin filament dynamics mediated by cofilin and associated proteins. Activated androgen receptor (AR) is believed to contribute to TNBC tumorigenesis. Our current work studied roles of activated AR and cofilin phospho-regulation during migration of three AR+ TNBC cell lines to determine if altered cofilin regulation can explain their migratory differences. Untreated or AR agonist-treated BT549, MDA-MB-453, and SUM159PT cells were compared to cells silenced for cofilin (KD) or AR expression/function (bicalutamide). Cofilin-1 was found to be the only ADF/cofilin isoform expressed in each TNBC line. Despite a significant increase in cofilin kinase caused by androgens, the ratio of cofilin:p-cofilin (1:1) did not change in SUM159PT cells. BT549 and MDA-MB-453 cells contain high p-cofilin levels which underwent androgen-induced dephosphorylation through increased cofilin phosphatase expression, but surprisingly maintain a leading-edge with high p-cofilin/total cofilin not found in SUM159PT cells. Androgens enhanced cell polarization in all lines, stimulated wound healing and transwell migration rates and increased N/E-cadherin mRNA ratios while reducing cell adhesion in BT549 and MDA-MB-453 cells. Cofilin KD negated androgen effects in MDA-MB-453 except for cell adhesion, while in BT549 cells it abrogated androgen-reduced cell adhesion. In SUM159PT cells, cofilin KD with and without androgens had similar effects in almost all processes studied. AR dependency of the processes were confirmed. In conclusion, cofilin regulation downstream of active AR is dependent on which actin-mediated process is being examined in addition to being cell line-specific. Although MDA-MB-453 cells demonstrated some control of cofilin through an AR-dependent mechanism, other AR-dependent pathways need to be further studied. Non-cofilin-dependent mechanisms that modulate migration of SUM159PT cells need to be investigated. Categorizing TNBC behavior as AR responsive and/or cofilin dependent can inform on decisions for therapeutic treatment.

The role of Colchicine on actin polymerization dynamics: as a potent anti-angiogenic factor

Over the years, cancer research has focused on different strategies to discover drugs and therapies to treat the metastatic stage of cancer. This stage depends upon the type, and the cause of cancer. One of the central facts about any cancer invasion is the formation of new blood vessels that provide nutrients to these uncontrollably dividing cells. This phenomenon is called angiogenesis and is responsible for tumor progression and metastasis. Tumor angiogenesis is a sequential process wherein various angiogenic factors produced by tumor cells bind to receptors of endothelial cells. This stimulates the cytoskeletal protein, especially actin to reorganize themselves and undergo the process of canalization. The driving force for such membrane transformation is spatially and temporally-regulated by polymerization of submembrane actin filaments. So far, Colchicine has been studied for its effectiveness in controlling microtubule reorganization during cell division, but its role is far from understood on actin polymerization. In our current study, we report the effect of Colchicine on actin polymerization dynamics using biophysical analysis like Right light scattering (RLS), Dynamic light scattering (DLS), Circular dichroism (CD) analysis, Scanning electron microscopy (SEM) study. Isothermal titration calorimetry (ITC) and kinetic measurements. Isothermal titration calorimetry (ITC) indicates multiple site binding for colchicine with actin aggregates. We have checked the in vivo effect of colchicine using end3 cells of Saccharomyces cerevisiae. We also report the anti-angiogenesis activity of colchicine via ex-ovo chicken chorioallantoic membrane (CAM) assay. We predict the target site of binding for the drug by docking studies. Based on our findings, we suggest the 'drug-repurposed' function for colchicine as a potential anti-angiogenic candidate.Communicated by Ramaswamy H. Sarma.

Hypomethylation-mediated upregulation of the WASF2 promoter region correlates with poor clinical outcomes in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common and lethal cancers worldwide. Wiskott–Aldrich syndrome protein family member 2 (WASF2) is an integral member of the actin cytoskeleton pathway, which plays a crucial role in cell motility. In this study, we aimed to explore the role of WASF2 in HCC carcinogenesis and its regulatory mechanism.

Methods

WASF2 expression in HCC was analyzed using six public RNA-seq datasets and 66 paired tissues from patients with HCC. The role of WASF2 in normal hepatocyte cell phenotypes was evaluated using a WASF2 overexpression vector in vitro; it was evaluated in HCC cell phenotypes using small interfering RNA (siRNA) in vitro and in vivo. Epigenetic regulatory mechanism of WASF2 was assessed in the Cancer Genome Atlas liver hepatocellular carcinoma project (TCGA_LIHC) dataset and also validated in 38 paired HCC tissues. Site mutagenesis, bisulfite sequencing polymerase chain reaction (BSP), methylation-specific polymerase chain reaction (MSP), and quantitative MSP (qMSP) were used for evaluating WASF2 methylation status.

Results

WASF2 is overexpressed in HCC and is clinically correlated with its prognosis. WASF2 overexpression promoted normal hepatocyte proliferation. WASF2 inactivation decreased the viability, growth, proliferation, migration, and invasion of Huh-7 and SNU475 HCC cells by inducing G2/M phase arrest. This induced cell death and inhibited epithelial–mesenchymal transition, hindering actin polymerization. In addition, WASF2 knockdown using siWASF2 in a xenograft mouse model and a lung metastasis model exerted tumor suppressive effect. There was a negative correlation between WASF2 methylation status and mRNA expression. The methylation pattern of CpG site 2 (− 726 bp), located in the WASF2 promoter, plays an important role in the regulation of WASF2 expression. Furthermore, the cg242579 CpG island in the WASF2 5′ promoter region was hypomethylated in HCC compared to that in the matched non-tumor samples. Patients with high WASF2 methylation and low WASF2 expression displayed the highest overall survival.

Conclusions

WASF2 is overexpressed and hypomethylated in HCC and correlates with patient prognosis. WASF2 inactivation exerts anti-tumorigenic effects on HCC cells in vitro and in vivo, suggesting that WASF2 could be a potential therapeutic target for HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02365-7.

Phenotyping of rare circulating cells in the blood of non-metastatic breast cancer patients using microfluidic Labyrinth technology

Label-free technologies for isolating rare circulating cells in breast cancer patients are widely available; however, they are mostly validated on metastatic patient blood samples. Given the need to use blood-based biomarkers to inform on disease progression and treatment decisions, it is important to validate these technologies in non-metastatic patient blood samples. In this study, we specifically focus on a recently established label-free microfluidic technology Labyrinth and assess its capabilities to phenotype a variety of rare circulating tumor cells indicative of epithelial-to-mesenchymal transition as well as cancer-associated macrophage-like (CAML) cells. We specifically chose a patient cohort that is non-metastatic and selected to undergo neoadjuvant chemotherapy to assess the performance of the Labyrinth technology. We enrolled 21 treatment naïve non-metastatic breast cancer patients of various disease stages. Our results indicate that (i) Labyrinth microfluidic technology is successfully able to isolate different phenotypes of CTCs despite the counts being low. (ii) Invasive phenotypes of CTCs such as transitioning CTCs and mesenchymal CTCs were found to be present in high numbers in stage III patients as compared to stage II patients. (iii) As the total load of CTCs increased, the mesenchymal CTCs were found to be increasing. (iv) Labyrinth was able to isolate CAMLs with the counts being higher in stage III patients as compared to stage II patients. Our study demonstrates the ability of the Labyrinth microfluidic technology to isolate rare cancer-associated cells from the blood of treatment naïve non-metastatic breast cancer patients, laying the foundation for tracking oncogenic spread and immune response in patients undergoing neoadjuvant chemotherapy.

High expression of Sam68 contributes to metastasis by regulating vimentin expression and a motile phenotype in oral squamous cell carcinoma

The present study aimed to investigate the clinical and biological significance of Src-associated in mitosis 68 kDa (Sam68) in oral squamous cell carcinoma (OSCC). Immunohistochemical analysis was performed on tissue samples obtained from 77 patients with OSCC. Univariate analysis revealed that the high expression of Sam68 was significantly correlated with advanced pathological T stage (P=0.01), positive lymphovascular invasion (P=0.01), and pathological cervical lymph node metastasis (P<0.01). Moreover, multivariate analysis demonstrated that the high expression of Sam68 was an independent predictive factor for cervical lymph node metastasis (odds ratio, 4.39; 95% confidence interval, 1.49-14.23; P<0.01). These results indicated that high Sam68 expression contributed to tumor progression, especially cervical lymph node metastasis, in OSCC. mRNA sequencing was also performed to assess the changes in the transcriptome between OSCC cells with Sam68 knockdown and control cells with the aim of elucidating the biological roles of Sam68. Gene Ontology enrichment analysis revealed that downregulated differentially expressed genes (DEGs) were concentrated in some biological processes related to epithelial-mesenchymal transition. Among these DEGs, it was established that vimentin was particularly downregulated in these cells. It was also confirmed that Sam68 knockdown reduced the motility of OSCC cells. Furthermore, the immunohistochemical study of vimentin identified the association between vimentin expression and Sam68 expression as well as cervical lymph node metastasis. In conclusion, the present study suggested that the high expression of Sam68 may contribute to metastasis by regulating vimentin expression and a motile mesenchymal phenotype in OSCC.

PKIB involved in the metastasis and survival of osteosarcoma

Osteosarcoma is frequently metastasized at the time of diagnosis in patients. However, the underlying mechanism of osteosarcoma metastasis remains poorly understood. In this study, we evaluated DNA methylation profiles combined with gene expression profiles of 21 patients with metastatic osteosarcoma and 64 patients with non-metastatic osteosarcoma from TARGET database and identified PKIB and AIM2 as hub genes related to the metastasis of osteosarcoma. To verify the effects of PKIB on migration and invasion of osteosarcoma, we performed wound-healing assay and transwell assay. The results showed that PKIB significantly inhibited the migration and invasion of osteosarcoma cells, and the Western blot experiments showed that the protein level of E-cad was upregulated and of VIM was downregulated in 143-B cell recombinant expression PKIB. These results indicate that PKIB inhibit the metastasis of osteosarcoma. CCK-8 assay results showed that PKIB promote the proliferation of osteosarcoma. In addition, the Western blot results showed that the phosphorylation level of Akt was upregulated in 143-B cells overexpressing PKIB, indicating that PKIB promotes the proliferation of osteosarcoma probably through signaling pathway that Akt involved in. These results give us clues that PKIB was a potential target for osteosarcoma therapy. Furthermore, combined clinical profiles analysis showed that the expression of AIM2- and PKIB- related risk scores was significantly related to the overall survival of patients with osteosarcoma. Thus, we constructed a nomogram based on AIM2 and PKIB expression–related risk scores for osteosarcoma prognostic assessment to predict the 1-, 2-, 3-, and 5-year overall survival rate of patients with metastatic osteosarcoma, assisting clinicians in the diagnosis and treatment of metastatic osteosarcoma.

Data driven and biophysical insights into the regulation of trafficking vesicles by extracellular matrix stiffness

Biomechanical signals from remodeled extracellular matrix (ECM) promote tumor progression. Here, we show that cell-matrix and cell-cell communication may be inherently linked and tuned through mechanisms of mechanosensitive biogenesis of trafficking vesicles. Pan-cancer analysis of cancer cells' mechanical properties (focusing primarily on cell stiffness) on substrates of varied stiffness and composition elucidated a heterogeneous cellular response to mechanical stimuli. Through machine learning, we identified a fingerprint of cytoskeleton-related proteins that accurately characterize cell stiffness in different ECM conditions. Expression of their respective genes correlates with patient prognosis across different tumor types. The levels of selected cytoskeleton proteins indicated that cortical tension mirrors the increase (or decrease) in cell stiffness with a change in ECM stiffness. A mechanistic biophysical model shows that the tendency for curvature generation by curvature-inducing proteins has an ultrasensitive dependence on cortical tension. This study thus highlights the effect of ECM stiffness, mediated by cortical tension, in modulating vesicle biogenesis.

Annona cherimola Mill. Leaf Extracts Affect Melanoma Cells Growth and Progression

Cancer represents one of the major causes of mortality worldwide; indeed, 19.3 million new cases and almost 10.0 million deaths were estimated last year. Among the different type of cancers, malignant melanoma represents the most aggressive and deadly skin cancer. Unfortunately, the long-term efficacy of melanoma treatments is limited by the lack of clinical efficacy, onset of side effects and resistance. The latter is a major obstacle for the success of the melanoma therapy; thus, the exploration of new potent and safer anticancer agents is of great importance. Recently, numerous plant species, used for therapeutic purposes and containing various non-toxic nutraceuticals have been widely studied. Herein, we investigated the antioxidant and anticancer properties on melanoma cells of the ethanolic, methanolic and aqueous Annona cherimola leaf extracts (ACE, ACM and ACW, respectively). The ethanolic extract showed higher anticancer activity, mostly against the malignant A2058 melanoma cell line (IC₅₀ = 5.6 ± 0.8 ng/mL), together with a very low activity on the normal cells. It blocks the melanoma cells migration process, and induces a clear disorganization of cytoskeleton, triggering cell apoptosis. Finally, some bioactive compounds were identified in the studied extracts.

Different hotspot p53 mutants exert distinct phenotypes and predict outcome of colorectal cancer patients

The TP53 gene is mutated in approximately 60% of all colorectal cancer (CRC) cases. Over 20% of all TP53-mutated CRC tumors carry missense mutations at position R175 or R273. Here we report that CRC tumors harboring R273 mutations are more prone to progress to metastatic disease, with decreased survival, than those with R175 mutations. We identify a distinct transcriptional signature orchestrated by p53R273H, implicating activation of oncogenic signaling pathways and predicting worse outcome. These features are shared also with the hotspot mutants p53R248Q and p53R248W. p53R273H selectively promotes rapid CRC cell spreading, migration, invasion and metastasis. The transcriptional output of p53R273H is associated with preferential binding to regulatory elements of R273 signature genes. Thus, different TP53 missense mutations contribute differently to cancer progression. Elucidation of the differential impact of distinct TP53 mutations on disease features may make TP53 mutational information more actionable, holding potential for better precision-based medicine.

Autophagy and EMT in cancer and metastasis: Who controls whom?

Metastasis consists of hallmark events, including Epithelial-Mesenchymal Transition (EMT), angiogenesis, initiation of inflammatory tumor microenvironment, and malfunctions in apoptosis. Autophagy is known to play a pivotal role in the metastatic process. Autophagy has pulled researchers towards it in recent times because of its dual role in the maintenance of cancer cells. Evidence states that cells undergoing EMT need autophagy in order to survive during migration and dissemination. Additionally, it orchestrates EMT markers in certain cancers. On the other side of the coin, autophagy plays an oncosuppressive role in impeding early metastasis. This review aims to project the interrelationship between autophagy and EMT. Targeting EMT via autophagy as a useful strategy is discussed in this review. Furthermore, for the first time, we have covered the possible reciprocating roles of EMT and autophagy and its consequences in cancer metastasis.

Pre-Treatment of Swine Oviductal Epithelial Cells with Progesterone Increases the Sperm Fertilizing Ability in an IVF Model

Mammalian spermatozoa are infertile immediately after ejaculation and need to undergo a functional modification, called capacitation, in order to acquire their fertilizing ability. Since oviductal epithelial cells (SOECs) and progesterone (P4) are two major modulators of capacitation, here we investigated their impact on sperm functionality by using an IVF swine model. To that, we treated SOECs with P4 at 10, 100, and 1000 ng/mL before the coincubation with spermatozoa, thus finding that P4 at 100 ng/mL does not interfere with the cytoskeleton dynamics nor the cells’ doubling time, but it promotes the sperm capacitation by increasing the number of spermatozoa per polyspermic oocyte (p < 0.05). Moreover, we found that SOECs pre-treatment with P4 100 ng/mL is able to promote an increase in the sperm fertilizing ability, without needing the hormone addition at the time of fertilization. Our results are probably due to the downregulation in the expression of OVGP1, SPP1 and DMBT1 genes, confirming an increase in the dynamism of our system compared to the classic IVF protocols. The results obtained are intended to contribute to the development of more physiological and efficient IVF systems.

A reversible metabolic stress-sensitive regulation of CRMP2A orchestrates EMT/stemness and increases metastatic potential in cancer

An epithelial-to-mesenchymal transition (EMT) phenotype with cancer stem cell-like properties is a critical feature of aggressive/metastatic tumors, but the mechanism(s) that promote it and its relation to metabolic stress remain unknown. Here we show that Collapsin Response Mediator Protein 2A (CRMP2A) is unexpectedly and reversibly induced in cancer cells in response to multiple metabolic stresses, including low glucose and hypoxia, and inhibits EMT/stemness. Loss of CRMP2A, when metabolic stress decreases (e.g., around blood vessels in vivo) or by gene deletion, induces extensive microtubule remodeling, increased glutamine utilization toward pyrimidine synthesis, and an EMT/stemness phenotype with increased migration, chemoresistance, tumor initiation capacity/growth, and metastatic potential. In a cohort of 27 prostate cancer patients with biopsies from primary tumors and distant metastases, CRMP2A expression decreases in the metastatic versus primary tumors. CRMP2A is an endogenous molecular brake on cancer EMT/stemness and its loss increases the aggressiveness and metastatic potential of tumors.

Reversing the Epithelial-Mesenchymal Transition in Metastatic Cancer Cells Using CD146-Targeted Black Phosphorus Nanosheets and a Mild Photothermal Treatment

Cancer metastasis leads to most deaths in cancer patients, and the epithelial-mesenchymal transition (EMT) is the key mechanism that endows the cancer cells with strong migratory and invasive abilities. Here, we present a nanomaterial-based approach to reverse the EMT in cancer cells by targeting an EMT inducer, CD146, using engineered black phosphorus nanosheets (BPNSs) and a mild photothermal treatment. We demonstrate this approach can convert highly metastatic, mesenchymal-type breast cancer cells to an epithelial phenotype (i.e., reversing EMT), leading to a complete stoppage of cancer cell migration. By using advanced nanomechanical and super-resolution imaging, complemented by immunoblotting, we validate the phenotypic switch in the cancer cells, as evidenced by the altered actin organization and cell morphology, downregulation of mesenchymal protein markers, and upregulation of epithelial protein markers. We also elucidate the molecular mechanism behind the reversal of EMT. Our results reveal that CD146-targeted BPNSs and a mild photothermal treatment synergistically contribute to EMT reversal by downregulating membrane CD146 and perturbing its downstream EMT-related signaling pathways. Considering CD146 overexpression has been confirmed on the surface of a variety of metastatic, mesenchymal-like cancer cells, this approach could be applicable for treating various cancer metastasis via modulating the phenotype switch in cancer cells.

RNA-binding motif protein 10 represses tumor progression through the Wnt/β- catenin pathway in lung adenocarcinoma

RNA-binding motif protein 10 (RBM10), one of the members of the RNA-binding protein (RBP) family, has a tumor suppressor role in multiple cancers. However, the functional role of RBM10 in lung adenocarcinoma (LUAD) and the underlying molecular mechanism remains unclear. In this study, we observed that RBM10 is significantly downregulated in LUAD tissues compared with normal tissues. Low RBM10 expression is significantly associated with poor outcome of LUAD patients. In vitro and in vivo experiments show that RBM10 inhibits cell proliferation, metastasis and EMT progression in LUAD. Mechanistically, we demonstrate that RBM10 interacts with β-catenin interacting protein 1 (CTNNBIP1) and positively regulates its expression, disrupting the binding of β-catenin to the transcription factor TCF/LEF, thereby inactivating the Wnt/β-catenin pathway. In conclusion, this is the first study reporting the role of RBM10 in suppressing LUAD progression at least via partly inactivating the Wnt/β-catenin pathway, which provides new insights into the tumorigenesis and metastasis of LUAD. Thus, RBM10 may be a promising new therapeutic target or clinical biomarker for LUAD therapy in the future.

The Transcription Factors Zeb1 and Snail Induce Cell Malignancy and Cancer Stem Cell Phenotype in Prostate Cells, Increasing Androgen Synthesis Capacity and Therapy Resistance

Prostate cancer (PCa) incidence has increased during the last decades, becoming one of the leading causes of death by cancer in men worldwide. During an extended period of prostate cancer, malignant cells are androgen-sensitive being testosterone the main responsible for tumor growth. Accordingly, treatments blocking production and action of testosterone are mostly used. However, during disease progression, PCa cells become androgen insensitive producing a castration-resistant stage with a worse prognosis. Overcoming castration-resistant prostate cancer (CRPC) has become a great challenge in the management of this disease. In the search for molecular pathways leading to therapy resistance, the epithelial-mesenchymal transition (EMT), and particularly the transcription factors zinc finger E-box-binding homeobox 1 (Zeb1) and zinc finger protein SNAI1 (Snail), master genes of the EMT, have shown to have pivotal roles. Also, the discovery that cancer stem cells (CSCs) can be generated de novo from their non-CSCs counterpart has led to the question whereas these EMT transcription factors could be implicated in this dynamic conversion between non-CSC and CSC. In this review, we analyze evidence supporting the idea that Zeb1 and Snail induce cell malignancy and cancer stem cell phenotype in prostate cells, increasing androgen synthesis capacity and therapy resistance.

Investigation of creep properties and the cytoskeletal structures of non-tumorigenic breast cells and triple-negative breast cancer cells

This article presents the correlation of creep and viscoelastic properties to the cytoskeletal structure of both tumorigenic and non-tumorigenic cells. Unique shear assay and strain mapping techniques were used to study the creep and viscoelastic properties of single non-tumorigenic and tumorigenic cells. At least 20 individual cells, three locations per cell, were studied. From the results, lower densities in the volume of actin, and keratin 18 structures were observed with the progression of cancer and were correlated to the increased creep rates and reduced mechanical properties (Young's moduli and viscosities) of tumorigenic (MDA-MB-231) cells. The study reveals significant differences between the creep and viscoelastic properties of non-tumorigenic breast cells versus tumorigenic cells. The variations in the creep strain rates are shown to be well characterized by lognormal distributions, while the statistical variations in the viscoelastic properties are well-described by normal distributions. The implications of the results are discussed for the study of discrete cell behaviors, strain and viscoelastic responses of the cell, and the role of cell cytoskeleton in the onset and progression of cancers.

Cytoskeleton Reorganization in EndMT-The Role in Cancer and Fibrotic Diseases

Chronic inflammation promotes endothelial plasticity, leading to the development of several diseases, including fibrosis and cancer in numerous organs. The basis of those processes is a phenomenon called the endothelial–mesenchymal transition (EndMT), which results in the delamination of tightly connected endothelial cells that acquire a mesenchymal phenotype. EndMT-derived cells, known as the myofibroblasts or cancer-associated fibroblasts (CAFs), are characterized by the loss of cell–cell junctions, loss of endothelial markers, and gain in mesenchymal ones. As a result, the endothelium ceases its primary ability to maintain patent and functional capillaries and induce new blood vessels. At the same time, it acquires the migration and invasion potential typical of mesenchymal cells. The observed modulation of cell shape, increasedcell movement, and invasion abilities are connected with cytoskeleton reorganization. This paper focuses on the review of current knowledge about the molecular pathways involved in the modulation of each cytoskeleton element (microfilaments, microtubule, and intermediate filaments) during EndMT and their role as the potential targets for cancer and fibrosis treatment.

The Underappreciated Role of Epithelial Mesenchymal Transition in Chronic Obstructive Pulmonary Disease and Its Strong Link to Lung Cancer

The World Health Organisation reported COPD to be the third leading cause of death globally in 2019, and in 2020, the most common cause of cancer death was lung cancer; when these linked conditions are added together they come near the top of the leading causes of mortality. The cell-biological program termed epithelial-to-mesenchymal transition (EMT) plays an important role in organ development, fibrosis and cancer progression. Over the past decade there has emerged a substantial literature that also links EMT specifically to the pathophysiology of chronic obstructive pulmonary disease (COPD) as primarily an airway fibrosis disease; COPD is a recognised strong independent risk factor for the development of lung cancer, over and above the risks associated with smoking. In this review, our primary focus is to highlight these linkages and alert both the COPD and lung cancer fields to these complex interactions. We emphasise the need for inter-disciplinary attention and research focused on the likely crucial roles of EMT (and potential for its inhibition) with recognition of its strategic place mechanistically in both COPD and lung cancer. As part of this we discuss the future potential directions for novel therapeutic opportunities, including evidence-based strategic repurposing of currently used familiar/approved medications.

Platelet-derived extracellular vesicles promote the migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes via CXCR2 signaling

Platelet-derived extracellular vesicles (PEVs), which are generated from the plasma membrane during platelet activation, may be involved in the inflammatory processes of rheumatoid arthritis (RA). The motility of RA fibroblast-like synoviocytes (RA-FLS) plays a key role in the development of synovial inflammation and joint erosion. However, the effects of PEVs on the motility of RA-FLS remain unclear. Thus, the present study aimed to investigate the active contents and potential molecular mechanisms underlying the role of PEVs in regulating the migration and invasion of RA-FLS. The results demonstrated that PEVs contain certain chemokines associated with cell migration and invasion, including C-C motif chemokine ligand 5, C-X-C motif chemokine ligand (CXCL)4 and CXCL7. Furthermore, SB225002, an antagonist of C-X-C motif chemokine receptor 2 (CXCR2; a CXCL7 receptor), partially prevented the migration and invasion of RA-FLS induced by PEVs, suggesting that PEVs may activate a CXCR2-mediated signaling pathway in RA-FLS. In addition, SB225002 antagonized the phosphorylation of IκB and NF-κB in RA-FLS induced by PEVs. Taken together, the results of the present study suggested that PEVs may promote the migration and invasion of RA-FLS by activating the NF-κB pathway mediated by the CXCR2 signaling pathway.

The miR-133a, TPM4 and TAp63γ Role in Myocyte Differentiation Microfilament Remodelling and Colon Cancer Progression

MicroRNAs (miRNAs) play an essential role in the regulation of a number of physiological functions. miR-133a and other muscular miRs (myomiRs) play a key role in muscle cell growth and in some type of cancers. Here, we show that miR133a is upregulated in individuals that undertake physical exercise. We used a skeletal muscle differentiation model to dissect miR-133a's role and to identify new targets, identifying Tropomyosin-4 (TPM4). This protein is expressed during muscle differentiation, but importantly it is an essential component of microfilament cytoskeleton and stress fibres formation. The microfilament scaffold remodelling is an essential step in cell transformation and tumour progression. Using the muscle system, we obtained valuable information about the microfilament proteins, and the knowledge on these molecular players can be transferred to the cytoskeleton rearrangement observed in cancer cells. Further investigations showed a role of TPM4 in cancer physiology, specifically, we found that miR-133a downregulation leads to TPM4 upregulation in colon carcinoma (CRC), and this correlates with a lower patient survival. At molecular level, we demonstrated in myocyte differentiation that TPM4 is positively regulated by the TA isoform of the p63 transcription factor. In muscles, miR-133a generates a myogenic stimulus, reducing the differentiation by downregulating TPM4. In this system, miR-133a counteracts the differentiative TAp63 activity. Interestingly, in CRC cell lines and in patient biopsies, miR-133a is able to regulate TPM4 activity, while TAp63 is not active. The downregulation of the miR leads to TPM4 overexpression, this modifies the architecture of the cell cytoskeleton contributing to increase the invasiveness of the tumour and associating with a poor prognosis. These results add data to the interesting question about the link between physical activity, muscle physiology and protection against colorectal cancer. The two phenomena have in common the cytoskeleton remodelling, due to the TPM4 activity, that is involved in stress fibres formation.

FHOD1 is upregulated in gastric cancer and promotes the proliferation and invasion of gastric cancer cells

Gastric cancer (GC) is one of the main causes of cancer-associated morbidity and mortality worldwide. The present study aimed to investigate the role of the gene encoding formin homology 2 domain containing 1 (FHOD1) protein in GC development. Data from The Cancer Genome Atlas were firstly analyzed, and immunohistochemistry was conducted on GC tissues. The results demonstrated that FHOD1 expression in GC tissues was significantly increased compared with adjacent non-tumor tissues. Furthermore, the expression level of FHOD1 was negatively associated with the overall survival of patients with GC. For the functional studies, lentivirus-mediated short hairpin RNA against FHOD1 and FHOD1-overexpression vectors were constructed to knockdown and overexpress the expression level of FHOD1 in human GC cell lines, respectively. The results indicated that FHOD1 knockdown inhibited the proliferation, colony formation and migratory and invasive abilities of GC cells. Conversely, overexpression of FHOD1 in GC cells promoted soft-agar colony formation and migratory and invasive abilities. In addition, it was demonstrated that genes of which expression levels were correlated with FHOD1 were enriched in the Gene Ontology term of 'extracellular matrix (ECM) structural constituent', suggesting that FHOD1 may serve an important role in the regulation of ECM. In conclusion, the present study demonstrated that FHOD1 may exert an oncogenic role in cultured GC cells and be inversely associated with the overall survival of patients with GC.

Cellular dynamics of EMT: lessons from live in vivo imaging of embryonic development

Epithelial-mesenchymal transition (EMT) refers to a process in which epithelial cells lose apical-basal polarity and loosen cell-cell junctions to take on mesenchymal cell morphologies and invasive properties that facilitate migration through extracellular matrix. EMT-and the reverse mesenchymal-epithelial transition (MET)-are evolutionarily conserved processes that are used throughout embryonic development to drive tissue morphogenesis. During adult life, EMT is activated to close wounds after injury, but also can be used by cancers to promote metastasis. EMT is controlled by several mechanisms that depend on context. In response to cell-cell signaling and/or interactions with the local environment, cells undergoing EMT make rapid changes in kinase and adaptor proteins, adhesion and extracellular matrix molecules, and gene expression. Many of these changes modulate localization, activity, or expression of cytoskeletal proteins that mediate cell shape changes and cell motility. Since cellular changes during EMT are highly dynamic and context-dependent, it is ideal to analyze this process in situ in living organisms. Embryonic development of model organisms is amenable to live time-lapse microscopy, which provides an opportunity to watch EMT as it happens. Here, with a focus on functions of the actin cytoskeleton, I review recent examples of how live in vivo imaging of embryonic development has led to new insights into mechanisms of EMT. At the same time, I highlight specific developmental processes in model embryos-gastrulation in fly and mouse embryos, and neural crest cell development in zebrafish and frog embryos-that provide in vivo platforms for visualizing cellular dynamics during EMT. In addition, I introduce Kupffer's vesicle in the zebrafish embryo as a new model system to investigate EMT and MET. I discuss how these systems have provided insights into the dynamics of adherens junction remodeling, planar cell polarity signaling, cadherin functions, and cytoskeletal organization during EMT, which are not only important for understanding development, but also cancer progression. These findings shed light on mechanisms of actin cytoskeletal dynamics during EMT, and feature live in vivo imaging strategies that can be exploited in future work to identify new mechanisms of EMT and MET. Video Abstract.

The GAS6-AXL signaling pathway triggers actin remodeling that drives membrane ruffling, macropinocytosis, and cancer-cell invasion

AXL, a member of the TAM (TYRO3, AXL, MER) receptor tyrosine kinase family, and its ligand, GAS6, are implicated in oncogenesis and metastasis of many cancer types. However, the exact cellular processes activated by GAS6-AXL remain largely unexplored. Here, we identified an interactome of AXL and revealed its associations with proteins regulating actin dynamics. Consistently, GAS6-mediated AXL activation triggered actin remodeling manifested by peripheral membrane ruffling and circular dorsal ruffles (CDRs). This further promoted macropinocytosis that mediated the internalization of GAS6-AXL complexes and sustained survival of glioblastoma cells grown under glutamine-deprived conditions. GAS6-induced CDRs contributed to focal adhesion turnover, cell spreading, and elongation. Consequently, AXL activation by GAS6 drove invasion of cancer cells in a spheroid model. All these processes required the kinase activity of AXL, but not TYRO3, and downstream activation of PI3K and RAC1. We propose that GAS6-AXL signaling induces multiple actin-driven cytoskeletal rearrangements that contribute to cancer-cell invasion.

Serum levels of cytoskeleton remodeling proteins and their mRNA expression in tumor tissue of metastatic laryngeal and hypopharyngeal cancers

Actin-binding proteins (ABPs) and various signaling systems are involved in the process of squamous cell carcinoma of the larynx and hypopharynx (SCCLH) metastasis. The clinical significance of these proteins has not yet been determined. We analyzed the relationship between the mRNA levels of cofilin 1 (CFL1), profilin 1 (PFN1), adenylyl cyclase-associated protein 1 (CAP1), SNAI1 and RND3 and SCCLH metastasis. The serum levels of the above ABPs were estimated and the relationship between them and their mRNA expressions was analyzed. The expression levels of ABP mRNAs were measured by real-time RT-PCR in paired tissue samples taken from 54 patients with SCCLH (T1-4N0-1M0). Expression analysis was performed using the 2^-ΔΔCT method. The levels of ABPs in the blood serum were measured by ELISA. Statistical analysis was carried out using the SPSS Statistica 20.0 software package. No significant difference in the mRNA gene expression in tumor tissue of patients with T1-3N0M0 SCCLH and patients with T2-4N1-2M0 SCCLH was found. High expression of RND3 mRNA was accompanied by an increase in mRNA expression of all studied ABPs. In the blood serum of T2-4N1-2M0 patients, the level of PFN1 was lower by 21% and the level of CAP1 was higher by 75% than those observed in T1-4N0M0 patients. The data obtained showed that RND3 is involved in the regulation of molecular cascades of SCCLH metastasis. PFN1 and CAP1 serum levels can be good classifiers of metastases in patients with SCCLH.

PLEK2, RRM2, GCSH: A Novel WWOX-Dependent Biomarker Triad of Glioblastoma at the Crossroads of Cytoskeleton Reorganization and Metabolism Alterations

Glioblastoma is one of the deadliest human cancers. Its malignancy depends on cytoskeleton reorganization, which is related to, e.g., epithelial-to-mesenchymal transition and metastasis. The malignant phenotype of glioblastoma is also affected by the WWOX gene, which is lost in nearly a quarter of gliomas. Although the role of WWOX in the cytoskeleton rearrangement has been found in neural progenitor cells, its function as a modulator of cytoskeleton in gliomas was not investigated. Therefore, this study aimed to investigate the role of WWOX and its collaborators in cytoskeleton dynamics of glioblastoma. Methodology on RNA-seq data integrated the use of databases, bioinformatics tools, web-based platforms, and machine learning algorithm, and the obtained results were validated through microarray data. PLEK2, RRM2, and GCSH were the most relevant WWOX-dependent genes that could serve as novel biomarkers. Other genes important in the context of cytoskeleton (BMP4, CCL11, CUX2, DUSP7, FAM92B, GRIN2B, HOXA1, HOXA10, KIF20A, NF2, SPOCK1, TTR, UHRF1, and WT1), metabolism (MTHFD2), or correlation with WWOX (COL3A1, KIF20A, RNF141, and RXRG) were also discovered. For the first time, we propose that changes in WWOX expression dictate a myriad of alterations that affect both glioblastoma cytoskeleton and metabolism, rendering new therapeutic possibilities.

The transcription factor Rreb1 regulates epithelial architecture, invasiveness, and vasculogenesis in early mouse embryos

Ras-responsive element-binding protein 1 (Rreb1) is a zinc-finger transcription factor acting downstream of RAS signaling. Rreb1 has been implicated in cancer and Noonan-like RASopathies. However, little is known about its role in mammalian non-disease states. Here, we show that Rreb1 is essential for mouse embryonic development. Loss of Rreb1 led to a reduction in the expression of vasculogenic factors, cardiovascular defects, and embryonic lethality. During gastrulation, the absence of Rreb1 also resulted in the upregulation of cytoskeleton-associated genes, a change in the organization of F-ACTIN and adherens junctions within the pluripotent epiblast, and perturbed epithelial architecture. Moreover, Rreb1 mutant cells ectopically exited the epiblast epithelium through the underlying basement membrane, paralleling cell behaviors observed during metastasis. Thus, disentangling the function of Rreb1 in development should shed light on its role in cancer and other diseases involving loss of epithelial integrity.

Proteomic and Bioinformatic Investigation of Altered Pathways in Neuroglobin-Deficient Breast Cancer Cells

Neuroglobin (NGB) is a myoglobin-like monomeric globin that is involved in several processes, displaying a pivotal redox-dependent protective role in neuronal and extra-neuronal cells. NGB remarkably exerts its function upon upregulation by NGB inducers, such as 17β-estradiol (E2) and H₂O₂. However, the molecular bases of NGB’s functions remain undefined, mainly in non-neuronal cancer cells. Human MCF-7 breast cancer cells with a knocked-out (KO) NGB gene obtained using CRISPR/Cas9 technology were analyzed using shotgun label-free quantitative proteomics in comparison with control cells. The differential proteomics experiments were also performed after treatment with E2, H₂O₂, and E2 + H₂O₂. All the runs acquired using liquid chromatography–tandem mass spectrometry were elaborated within the same MaxQuant analysis, leading to the quantification of 1872 proteins in the global proteomic dataset. Then, a differentially regulated protein dataset was obtained for each specific treatment. After the proteomic study, multiple bioinformatics analyses were performed to highlight unbalanced pathways and processes. Here, we report the proteomic and bioinformatic investigations concerning the effects on cellular processes of NGB deficiency and cell treatments. Globally, the main processes that were affected were related to the response to stress, cytoskeleton dynamics, apoptosis, and mitochondria-driven pathways.

Keratins determine network stress responsiveness in reconstituted actin-keratin filament systems

The cytoskeleton is a major determinant of cell mechanics, and alterations in the central mechanical aspects of cells are observed during many pathological situations. Therefore, it is essential to investigate the interplay between the main filament systems of the cytoskeleton in the form of composite networks. Here, we investigate the role of keratin intermediate filaments (IFs) in network strength by studying in vitro reconstituted actin and keratin 8/18 composite filament networks via bulk shear rheology. We co-polymerized these structural proteins in varying ratios and recorded how their relative content affects the overall mechanical response of the various composites. For relatively small deformations, we found that all composites exhibited an intermediate linear viscoelastic behaviour compared to that of the pure networks. In stark contrast, when larger deformations were imposed the composites displayed increasing strain stiffening behaviour with increasing keratin content. The extent of strain stiffening is much more pronounced than in corresponding experiments performed with vimentin IF as a composite network partner for actin. Our results provide new insights into the mechanical interplay between actin and keratin filaments in which keratin provides reinforcement to actin. This interplay may contribute to the overall integrity of cells. Hence, the high keratin 8/18 content of mechanically stressed simple epithelial cell layers, as found in the lung and the intestine, provides an explanation for their exceptional stability.

Cytoskeletal Dynamics in Epithelial-Mesenchymal Transition: Insights into Therapeutic Targets for Cancer Metastasis

In cancer cells, a vital cellular process during metastasis is the transformation of epithelial cells towards motile mesenchymal cells called the epithelial to mesenchymal transition (EMT). The cytoskeleton is an active network of three intracellular filaments: actin cytoskeleton, microtubules, and intermediate filaments. These filaments play a central role in the structural design and cell behavior and are necessary for EMT. During EMT, epithelial cells undergo a cellular transformation as manifested by cell elongation, migration, and invasion, coordinated by actin cytoskeleton reorganization. The actin cytoskeleton is an extremely dynamic structure, controlled by a balance of assembly and disassembly of actin filaments. Actin-binding proteins regulate the process of actin polymerization and depolymerization. Microtubule reorganization also plays an important role in cell migration and polarization. Intermediate filaments are rearranged, switching to a vimentin-rich network, and this protein is used as a marker for a mesenchymal cell. Hence, targeting EMT by regulating the activities of their key components may be a potential solution to metastasis. This review summarizes the research done on the physiological functions of the cytoskeleton, its role in the EMT process, and its effect on multidrug-resistant (MDR) cancer cells-highlight some future perspectives in cancer therapy by targeting cytoskeleton.

Erianthridin suppresses non-small-cell lung cancer cell metastasis through inhibition of Akt/mTOR/p70S6K signaling pathway

Cancer metastasis is a major cause of the high mortality rate in lung cancer patients. The cytoskeletal rearrangement and degradation of extracellular matrix are required to facilitate cell migration and invasion and the suppression of these behaviors is an intriguing approach to minimize cancer metastasis. Even though Erianthridin (ETD), a phenolic compound isolated from the Thai orchid Dendrobium formosum exhibits various biological activities, the molecular mechanism of ETD for anti-cancer activity is unclear. In this study, we found that noncytotoxic concentrations of ETD (≤ 50 μM) were able to significantly inhibit cell migration and invasion via disruption of actin stress fibers and lamellipodia formation. The expression of matrix metalloproteinase-2 (MMP-2) and MMP-9 was markedly downregulated in a dose-dependent manner after ETD treatment. Mechanistic studies revealed that protein kinase B (Akt) and its downstream effectors mammalian target of rapamycin (mTOR) and p70 S6 kinase (p70^S6K) were strongly attenuated. An in silico study further demonstrated that ETD binds to the protein kinase domain of Akt with both hydrogen bonding and van der Waals interactions. In addition, an in vivo tail vein injection metastasis study demonstrated a significant effect of ETD on the suppression of lung cancer cell metastasis. This study provides preclinical information regarding ETD, which exhibits promising antimetastatic activity against non-small-cell lung cancer through Akt/mTOR/p70^S6K-induced actin reorganization and MMPs expression.