Extracellular vesicles as central regulators of blood vessel function in cancer

Commercially Available Ultrasound Contrast Agents: Factors Contributing to Favorable Outcomes With Ultrasound-Mediated Drug Delivery and Ultrasound Localization Microscopy Imaging

ABSTRACT

Ultrasound contrast agents (UCAs) are microbubbles comprising an inert gas core stabilized by an encapsulating shell, which serves to increase the signal-to-noise ratio of blood-to-tissue in diagnostic ultrasound imaging. More recently, research has investigated the use of UCAs to combine both diagnostics and therapeutic outcomes in an amalgamated approach, designated 'theranostics.' Two examples of theranostic based approaches include the use of super-resolution imaging with ultrasound localized microscopy (ULM) and ultrasound-mediated drug delivery (UMDD). Both ULM and UMDD have been shown to have the potential to improve both patient care and clinical outcomes. Currently, there are 4 commercially available global UCAs licensed for clinical use. The physico-chemical properties of each of these UCAs influence its potential theranostic efficacy. Because of differences in their composition and/or manufacturing processes, each UCA has different characteristics that contribute to different in vivo resonance behavior, which in turn influences their effective clinical applications. This review highlights the key physico-chemical characteristic differences of the 4 commercially available contrast agents, with specific emphasis on their gaseous core, shell composition, and microbubble volume distribution, while providing novel insights into their benefits for supporting emerging clinical technologies, specifically ULM and UMDD.

Oscillating microbubble array-based metamaterials (OMAMs) for rapid isolation of high-purity exosomes

Exosomes secreted by cells hold substantial potential for disease diagnosis and treatment. However, the rapid isolation of high-purity exosomes and their subpopulations from biofluids (e.g., undiluted whole blood) remains challenging. This study presents oscillating microbubble array-based metamaterials (OMAMs) for enabling the rapid isolation of high-purity exosomes and their subpopulations from biofluids without labeling or preprocessing. Particularly, leveraging acoustically excited microbubble oscillation, OMAMs can generate numerous acoustofluidic traps for filtering in-fluid micro/nanoparticles, thus allowing for removing bioparticles larger than exosomes to obtain high-purity (93%) exosomes from undiluted whole blood in ~3 minutes. Moreover, exosome subpopulations in different size ranges can be isolated by tuning the microbubble oscillation amplitude. Additionally, as each oscillating microbubble functions as an ultradeep subwavelength (~λ/186) acoustic amplifier and a nonlinear source, OMAMs can generate high-resolution complex acoustic energy patterns and tune the patterns by activating different-sized microbubbles at their distinct resonance frequencies.

Immune-Infiltrated Cancer Spheroid Model with Vascular Recirculation Reveals Temporally Dependent and Tissue-Specific Macrophage Recruitment

Immune cell infiltration in tumors has been reported to influence tumor progression and clinical outcomes. Considerable efforts have been made to understand interactions between tumors and the immune system. However, current models are either not comprehensive or limited to short-term studies. Recognizing thedynamic and long-term nature of tumor-immune interactions, an immune-infiltrated cancer spheroid model is developed by continuously perfusing and recirculating immune cells with gravity-driven flow through a tubular blood vessel adjacent to a cancer spheroid. Fibroblasts and pericytes are embedded in the gel matrix to support endothelial cells and enhance the vascular barrier. With continuous monocyte recirculation, monocyte adhesion, transendothelium migration, differentiation, and macrophage recruitment into breast carcinoma and hepatoma spheroids is successfully demonstrated over a week. The macrophage recruitment process is temporally dependent and tissue-specific, leading to the formation of cancer-macrophage heterospheroids. Elevated secretion of granulocyte-macrophage colony-stimulating factor (GM-CSF), which regulates monocyte recruitment and macrophage activation, is observed in the breast carcinoma model. Increased levels of Interleukin 6 (IL-6) and Interleukin 8 (IL-8) are detected, indicating a pro-inflammatory environment associated with tumor progression and metastasis. This platform provides a valuable framework for investigating immune cell infiltration and differentiation within the tumor microenvironment, supporting the advancement of cancer immunotherapies.

Extracellular Vesicle-Associated Angiopoietin-2 and Cell Migration-Inducing Protein in Lung Cancer Progression and Brain Metastases

BACKGROUND

Angiopoietin-2 (ANGPT2) and cell migration-inducing protein (CEMIP) are key regulators of angiogenesis, extracellular matrix remodeling, and metastatic progression in various cancers, including lung cancer (LC). The presence of these biomarkers in extracellular vesicles (EVs) may offer valuable insights into the molecular mechanisms underlying LC progression and metastasis. Extracellular vesicles play a critical role in LC by enhancing intercellular communication and supporting processes such as angiogenesis, immune evasion, and metastasis, transferring key molecules like vascular endothelial growth factor (VEGF) and pro-angiogenic microRNAs (miRNAs).

METHODS

This study aimed to investigate the presence and quantification of ANGPT2 and CEMIP in the cargo of EVs isolated from plasma samples obtained from the peripheral venous blood of patients with localized lung cancer (LLC group), lung cancer with brain metastases (LCM group), and healthy controls (HC group). EVs were isolated using the density gradient ultracentrifugation method, and their characterization was performed through scanning and transmission electron microscopy as well as flow cytometry. Western blot analysis was used to identify ANGPT2 and CEMIP in EV cargo, and band intensity from western blot images was quantified using specialized software.

RESULTS

The expression of ANGPT2 and CEMIP in EV cargo was significantly higher in the oncologic groups (LLC and LCM combined) compared to the HC group. Notably, EV CEMIP levels were, on average, 59% higher in patients with brain metastases than in those with localized lung cancer. Following surgical resection, postoperative EV ANGPT2 and EV CEMIP levels decreased by 36% and 8.5%, respectively, in the LLC group, and by 40% and 4.6%, respectively, in the LCM group.

CONCLUSION

These findings emphasize the potential of ANGPT2 and CEMIP as biomarkers for LC progression and prognosis. To our knowledge, no previous study has evaluated the presence and quantification of ANGPT2 and CEMIP in EV cargo from lung cancer patients. To further validate their role in cancer progression, functional studies should explore the mechanistic effects of EV-associated ANGPT2 and CEMIP on angiogenesis, immune modulation, cell migration, extracellular matrix remodeling, and tumor progression in lung cancer models.

Engineered Immunomodulatory Extracellular Vesicles from Epithelial Cells with the Capacity for Stimulation of Innate and Adaptive Immunity in Cancer and Autoimmunity

Extracellular vesicles (EVs) are generated in all cells. Systemic administration of allogenic EVs derived from epithelial and mesenchymal cells has been shown to be safe, despite carrying an array of functional molecules, including thousands of proteins. To address whether epithelial cell-derived EVs can be modified to acquire the capacity to induce an immune response, we engineered 293T EVs to harbor the immunomodulatory molecules CD80, OX40L, and PD-L1. We demonstrated abundant levels of these proteins in the engineered cells and EVs. Functionally, the engineered EVs efficiently elicited positive and negative costimulation of human and murine T cells. In the setting of cancer and autoimmune hepatitis, the engineered EVs modulated T cell functions and altered disease progression. OX40L EVs also provided enhanced antitumor activity in combination with anti-CTLA-4 in melanoma-bearing mice. In addition, we added multiple immunomodulatory proteins in EVs (EVmIM), attempting to elicit an immune response in both lymphoid and myeloid compartments. The EVmIM containing CD80, 4-1BBL, CD40L, CD2, and CD32 engaged both T cells and antigen presenting cells (APCs) in melanoma tumors, demonstrating the capacity for EVmIM to elicit antitumor activity. Our work provides evidence that EVs can be engineered to induce specific immune responses with translational potential to modulate immune cell functions in pathological settings.

Dynamics of intracellular and intercellular redox communication

Cell and organ metabolism is organized through various signaling mechanisms, including redox, Ca2+, kinase and electrochemical pathways. Redox signaling operates at multiple levels, from interactions between individual molecules in their microenvironment to communication among subcellular organelles, single cells, organs, and the entire organism. Redox communication is a dynamic and ongoing spatiotemporal process. This article focuses on hydrogen peroxide (H2O2), a key second messenger that targets redox-active protein cysteine thiolates. H2O2 gradients across cell membranes are controlled by peroxiporins, specialized aquaporins. Redox-active endosomes, known as redoxosomes, form at the plasma membrane. Cell-to-cell redox communication involves direct contacts, such as per gap junctions that connect cells for transfer of molecules via connexons. Moreover, signaling occurs through the release of redox-active molecules and enzymes into the surrounding space, as well as through various types of extracellular vesicles (EVs) that transport these signals to nearby or distant target cells.

Proteomic studies of VEGFR2 in human placentas reveal protein associations with preeclampsia, diabetes, gravidity, and labor

VEGFR2 (Vascular endothelial growth factor receptor 2) is a central regulator of placental angiogenesis. The study of the VEGFR2 proteome of chorionic villi at term revealed its partners MDMX (Double minute 4 protein) and PICALM (Phosphatidylinositol-binding clathrin assembly protein). Subsequently, the oxytocin receptor (OT-R) and vasopressin V1aR receptor were detected in MDMX and PICALM immunoprecipitations. Immunogold electron microscopy showed VEGFR2 on endothelial cell (EC) nuclei, mitochondria, and Hofbauer cells (HC), tissue-resident macrophages of the placenta. MDMX, PICALM, and V1aR were located on EC plasma membranes, nuclei, and HC nuclei. Unexpectedly, PICALM and OT-R were detected on EC projections into the fetal lumen and OT-R on 20-150 nm clusters therein, prompting the hypothesis that placental exosomes transport OT-R to the fetus and across the blood-brain barrier. Insights on gestational complications were gained by univariable and multivariable regression analyses associating preeclampsia with lower MDMX protein levels in membrane extracts of chorionic villi, and lower MDMX, PICALM, OT-R, and V1aR with spontaneous vaginal deliveries compared to cesarean deliveries before the onset of labor. We found select associations between higher MDMX, PICALM, OT-R protein levels and either gravidity, diabetes, BMI, maternal age, or neonatal weight, and correlations only between PICALM-OT-R (p < 2.7 × 10-8), PICALM-V1aR (p < 0.006), and OT-R-V1aR (p < 0.001). These results offer for exploration new partnerships in metabolic networks, tissue-resident immunity, and labor, notably for HC that predominantly express MDMX.

Quantitative analysis of pre-treatment dynamic contrast-enhanced ultrasound for assessing the response of colorectal liver metastases to chemotherapy plus targeted therapy: a dual-institutional study

OBJECTIVES

To investigate the clinical value of pre-treatment quantitative contrast-enhanced ultrasound (CEUS) in assessing the response of colorectal liver metastases (CRLM) to chemotherapy plus targeted therapy.

METHODS

This study retrospectively enrolled 50 CRLM patients from the Zhongshan Hospital, Fudan University as the training cohort and 14 patients from Shanghai Tenth People's Hospital as the testing cohort. Patients underwent the CEUS examination before receiving chemotherapy (CAPOX, FOLFOX, FOLFIRI, or FOLFOXIRI) plus targeted therapy (Bevacizumab or Cetuximab). The therapy response was determined according to Response Evaluation Criteria in Solid Tumors version 1.1 based on pre-treatment CT and 3-month follow-up CT after therapy. Dynamic analysis was performed by VueBox® software. Time-intensity curves with quantitative perfusion parameters were obtained. In the training cohort, univariable and multivariable logistic regression analyses were used to develop the predictive model of therapy response. The predictive performance of the developed model was validated in the testing cohort.

RESULTS

After the logistic regression analyses, the peak enhancement (PE) (odds ratio = 1.640; 95% confidence intervals [CI] 1.022-2.633) and time to peak (TTP) (odds ratio = 0.495; 95% CI 0.246-0.996) were determined as independent predictive factors. PE and TTP generated from VueBox® were not affected by ultrasound instruments and contrast agent dosage in therapy response evaluation (P > 0.05). The logistic regression model achieved satisfactory prediction performance (area under the curve: 0.923 in the training cohort and 0.854 in the testing cohort).

CONCLUSION

CEUS with dynamic quantitative perfusion analysis, which presents high consistency, has potential practical value in predicting the response of CRLM to chemotherapy plus targeted therapy.

Extracellular vesicles associated microRNAs: Their biology and clinical significance as biomarkers in gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal, gastric, esophageal, pancreatic, and liver, are associated with high mortality and morbidity rates worldwide. One of the underlying reasons for the poor survival outcomes in patients with these malignancies is late disease detection, typically when the tumor has already advanced and potentially spread to distant organs. Increasing evidence indicates that earlier detection of these cancers is associated with improved survival outcomes and, in some cases, allows curative treatments. Consequently, there is a growing interest in the development of molecular biomarkers that offer promise for screening, diagnosis, treatment selection, response assessment, and predicting the prognosis of these cancers. Extracellular vesicles (EVs) are membranous vesicles released from cells containing a repertoire of biological molecules, including nucleic acids, proteins, lipids, and carbohydrates. MicroRNAs (miRNAs) are the most extensively studied non-coding RNAs, and the deregulation of miRNA levels is a feature of cancer cells. EVs miRNAs can serve as messengers for facilitating interactions between tumor cells and the cellular milieu, including immune cells, endothelial cells, and other tumor cells. Furthermore, recent years have witnessed considerable technological advances that have permitted in-depth sequence profiling of these small non-coding RNAs within EVs for their development as promising cancer biomarkers -particularly non-invasive, liquid biopsy markers in various cancers, including GI cancers. Herein, we summarize and discuss the roles of EV-associated miRNAs as they play a seminal role in GI cancer progression, as well as their promising translational and clinical potential as cancer biomarkers as we usher into the area of precision oncology.

Modelling the complex nature of the tumor microenvironment: 3D tumor spheroids as an evolving tool

Cancer remains a serious burden in society and while the pace in the development of novel and more effective therapeutics is increasing, testing platforms that faithfully mimic the tumor microenvironment are lacking. With a clear shift from animal models to more complex in vitro 3D systems, spheroids emerge as strong options in this regard. Years of development have allowed spheroid-based models to better reproduce the biomechanical cues that are observed in the tumor-associated extracellular matrix (ECM) and cellular interactions that occur in both a cell-cell and cell-ECM manner. Here, we summarize some of the key cellular interactions that drive tumor development, progression and invasion, and how successfully are these interactions recapitulated in 3D spheroid models currently in use in the field. We finish by speculating on future advancements in the field and on how these can shape the relevance of spherical 3D models for tumor modelling.

Intercellular Molecular Transfer Mediated by Extracellular Vesicles in Cancer

Among multiple pathways of intercellular communication operative in multicellular organisms, the trafficking of extracellular vesicles (EVs) and particles (EP) represents a unique mode of cellular information exchange with emerging roles in health and disease, including cancer. A distinctive feature of EV/EP-mediated cell-cell communication is that it involves simultaneous short- or long-range transfer of numerous molecular constituents (cargo) from donor to recipient cells. EV/EP uptake by donor cells elicits signalling or metabolic responses, or else leads to EV-re-emission or degradation. EVs are heterogeneous membranous structures released from cells via increasingly defined mechanisms involving either formation of multivesicular endosomes (exosomes) or budding from the plasma membrane (ectosomes). EPs (exomeres, supermeres) are membraneless complex particles, smaller than EVs and of less defined biogenesis and function. EVs/EPs carry complex assemblies of proteins, lipids and nucleic acids (RNA, DNA), which they shuttle into intercellular milieu, body fluids and recipient cells, via surface contact, fusion and different forms of internalization (endocytosis, micropinocytosis). While the physiological functions of EVs/EPs communication pathways continue to be investigated, their roles in cancer are increasingly well-defined. For example, EVs are involved in the transmission of cancer-specific molecular cargo, including mutant, oncogenic, transforming, or regulatory macromolecules to indolent, or normal cells, sometimes triggering their quasi-transformation-like states, or phenotypic alterations. Conversely, a reciprocal and avid uptake of stromal EVs by cancer cells may be responsible for modulating their oncogenic repertoire, as exemplified by the angiocrine effects of endothelial EVs influencing cancer cell stemness. EV exchanges during cancer progression have also been implicated in the formation of tumour stroma, angiogenesis and non-angiogenic neovascularization processes, immunosuppression, colonization of metastatic organ sites (premetastatic niche), paraneoplastic and systemic pathologies (thrombosis, diabetes, hepatotoxicity). Thus, an EV/EP-mediated horizontal transfer of cellular content emerges as a new dimension in cancer pathogenesis with functional, diagnostic, and therapeutic implications.

Basic Pathogenic Mechanisms and Epigenetic Players Promoted by Extracellular Vesicles in Vascular Damage

Both progression from the early pathogenic events to clinically manifest cardiovascular diseases (CVD) and cancer impact the integrity of the vascular system. Pathological vascular modifications are affected by interplay between endothelial cells and their microenvironment. Soluble factors, extracellular matrix molecules and extracellular vesicles (EVs) are emerging determinants of this network that trigger specific signals in target cells. EVs have gained attention as package of molecules with epigenetic reversible activity causing functional vascular changes, but their mechanisms are not well understood. Valuable insights have been provided by recent clinical studies, including the investigation of EVs as potential biomarkers of these diseases. In this paper, we review the role and the mechanism of exosomal epigenetic molecules during the vascular remodeling in coronary heart disease as well as in cancer-associated neoangiogenesis.