Secretion rates and protein composition of extracellular vesicles released by cancer-associated fibroblasts after radiation

Effects of extracellular vesicle-derived noncoding RNAs on pre-metastatic niche and tumor progression

A pre-metastatic niche (PMN) is a protective microenvironment that facilitates the colonization of disseminating tumor cells in future metastatic organs. Extracellular vesicles (EVs) play a role in intercellular communication by delivering cargoes, such as noncoding RNAs (ncRNAs). The pivotal role of extracellular vesicle-derived noncoding RNAs (EV-ncRNAs) in the PMN has attracted increasing attention. In this review, we summarized the effects of EV-ncRNAs on the PMN in terms of immunosuppression, vascular permeability and angiogenesis, inflammation, metabolic reprogramming, and fibroblast alterations. In particular, we provided a comprehensive overview of the effects of EV-ncRNAs on the PMN in different cancers. Finally, we discussed the promising clinical applications of EV-ncRNAs, including their potential as diagnostic and prognostic markers and therapeutic targets.

A bibliometric and visual analysis of cancer-associated fibroblasts

Background

Cancer-associated fibroblasts (CAFs) represent the predominant stromal component within the tumour microenvironment (TME), exhibiting considerable heterogeneity and plasticity that significantly impact immune response and metabolic reprogramming within the TME, thereby influencing tumour progression. Consequently, investigating CAFs is of utmost importance. The objective of this study is to employ bibliometric analysis in order to evaluate the current state of research on CAFs and predict future areas of research and emerging trends.

Methods

Conduct a comprehensive search for scholarly publications within the Web of Science Core Collection database, encompassing the time period from January 1, 2001, to December 31, 2022. Apply VOSviewer, CiteSpace, R software and Microsoft Excel for bibliometric analysis and visualisation.

Results

This study involved a comprehensive analysis of 5,925 publications authored by 33,628 individuals affiliated with 4,978 institutions across 79 countries/regions. These publications were published in 908 journals, covering 14,495 keywords and 203,947 references. Notably, there was a significant increase in articles published between 2019 and 2022. China had the highest count of articles, while the United States emerged as the most frequently cited country. The primary research institutions in this field were Shanghai Jiao Tong University, Harvard University, and the University of Texas MD Anderson Cancer Center. Sotgia, Federica and Lisanti, Michael P from the University of Manchester, and Martinet, Wim from the University of Antwerp were the most prolific and highly cited authors. The journal Cancers had the highest number of publications, while Cancer Research was the most frequently cited journal. Molecular, biology, immunology, medicine and genetics were the main research disciplines in the field of CAFs. Key directions in CAFs research encompassed the study of transforming growth factor-β, Fibroblast Activation Protein, breast cancer, as well as growth and metastasis. The findings from the analysis of keyword co-occurrence and literature co-citation have revealed several emerging hotspots and trends within the field of CAFs. These include STAT3, multidrug resistance, pancreatic ductal adenocarcinoma, pan-cancer analysis, preclinical evaluation, ionizing radiation, and gold nanoparticles.

Conclusion

Targeting CAFs is anticipated to be a novel and effective strategy for cancer treatment. This study provides a comprehensive overview of the existing research on CAFs from 2001 to 2022, utilizing bibliometric analysis. The study identified the prominent areas of investigation and anticipated future research directions, with the aim of providing valuable insights and recommendations for future studies in the field of CAFs.

Non-immune cell components in tumor microenvironment influencing lung cancer Immunotherapy

Lung cancer (LC) is one of the leading causes of cancer-related deaths worldwide, with a significant morbidity and mortality rate, endangering human life and health. The introduction of immunotherapies has significantly altered existing cancer treatment strategies and is expected to improve immune responses, objective response rates, and survival rates. However, a better understanding of the complex immunological networks of LC is required to improve immunotherapy efficacy further. Tumor-associated antigens (TAAs) and tumor-specific antigens (TSAs) are significantly expressed by LC cells, which activate dendritic cells, initiate antigen presentation, and activate lymphocytes to exert antitumor activity. However, as tumor cells combat the immune system, an immunosuppressive microenvironment forms, enabling the enactment of a series of immunological escape mechanisms, including the recruitment of immunosuppressive cells and induction of T cell exhaustion to decrease the antitumor immune response. In addition to the direct effect of LC cells on immune cell function, the secreting various cytokines, chemokines, and exosomes, changes in the intratumoral microbiome and the function of cancer-associated fibroblasts and endothelial cells contribute to LC cell immune escape. Accordingly, combining various immunotherapies with other therapies can elicit synergistic effects based on the complex immune network, improving immunotherapy efficacy through multi-target action on the tumor microenvironment (TME). Hence, this review provides guidance for understanding the complex immune network in the TME and designing novel and effective immunotherapy strategies for LC.

Methodologies to evaluate the radiation-induced changes on extracellular vesicles

The extracellular vesicles (EVs) are carriers that actively transfer functional biomolecules between cells affecting the intercellular communication (Pitt, Kroemer, & Zitvogel, 2016). EV signaling has consequences on the targeted cell behavior impacting multiple processes from health to disease, including cancer (Yates et al., 2022). Radiation treatment (RT) is one of the gold standard and effective treatments for cancer, as curative or palliative (Chandra, Keane, Voncken, & Thomas, 2021). RT induces different release of EVs and their cargo is altered. In addition, the uptake of EVs secreted by irradiated cells is affected. Hence, a deep investigation is required to better understand how RT influence the cell-to-cell communication thought signals shuttle by EVs. Here, detailed methods to study the RT effects on EV size and secretion, EV protein expression, EV uptake will be described. Alterations and adaptions might make the protocols applicable to different cell lines, and with different types of RT and dose exposures.

Cancer-associated fibroblasts in radiotherapy: Bystanders or protagonists?

BACKGROUND

The primary goal of radiotherapy (RT) is to induce cellular damage on malignant cells; however, it is becoming increasingly recognized the important role played by the tumor microenvironment (TME) in therapy outcomes. Therapeutic irradiation of tumor lesions provokes profound cellular and biological reconfigurations within the TME that ultimately may influence the fate of the therapy.

MAIN CONTENT

Cancer-associated fibroblasts (CAFs) are known to participate in all stages of cancer progression and are increasingly acknowledged to contribute to therapy resistance. Accumulated evidence suggests that, upon radiation, fibroblasts/CAFs avoid cell death but instead enter a permanent senescent state, which in turn may influence the behavior of tumor cells and other components of the TME. Despite the proposed participation of senescent fibroblasts on tumor radioprotection, it is still incompletely understood the impact that RT has on CAFs and the ultimate role that irradiated CAFs have on therapy outcomes. Some of the current controversies may emerge from generalizing observations obtained using normal fibroblasts and CAFs, which are different cell entities that may respond differently to radiation exposure.

CONCLUSION

In this review we present current knowledge on the field of CAFs role in radiotherapy; we discuss the potential tumorigenic functions of radiation-induced senescent fibroblasts and CAFs and we make an effort to integrate the knowledge emerging from preclinical experimentation with observations from the clinics. Video Abstract.

The miR-126-5p and miR-212-3p in the extracellular vesicles activate monocytes in the early stage of radiation-induced vascular inflammation implicated in atherosclerosis

People exposed to radiation in cancer therapy and nuclear accidents are at increased risk of cardiovascular outcomes in long-term survivors. Extracellular vesicles (EVs) are involved in radiation-induced endothelial dysfunction, but their role in the early stage of vascular inflammation after radiation exposure remains to be fully understood. Herein, we demonstrate that endothelial cell-derived EVs containing miRNAs initiate monocyte activation in radiation-induced vascular inflammation. In vitro co-culture and in vivo experimental data showed that endothelial EVs can be sensitively increased by radiation exposure in a dose-dependent manner, and stimulate monocytes releasing monocytic EVs and adhesion to endothelial cells together with an increase in the expression of genes encoding specific ligands for cell-cell interaction. Small RNA sequencing and transfection using mimics and inhibitors explained that miR-126-5p and miR-212-3p enriched in endothelial EVs initiate vascular inflammation by monocyte activation after radiation exposure. Moreover, miR-126-5p could be detected in the circulating endothelial EVs of radiation-induced atherosclerosis model mice, which was found to be tightly correlated with the atherogenic index of plasma. In summary, our study showed that miR-126-5p and miR-212-3p present in the endothelial EVs mediate the inflammatory signals to activate monocytes in radiation-induced vascular injury. A better understanding of the circulating endothelial EVs content can promote their use as diagnostic and prognostic biomarkers for atherosclerosis after radiation exposure.

Melanoma Cells Produce Large Vesicular-Bodies That Cause Rapid Disruption of Brain Endothelial Barrier-Integrity and Disassembly of Junctional Proteins

It is known that many cells produce extracellular vesicles, and this includes a range of different cancer cell types. Here we demonstrate the profound effects of large vesicular-like bodies produced by melanoma cells on the barrier integrity of human brain endothelial cells. These vesicular-bodies have not been fully characterised but range in size from ~500 nm to >10 µm, are surrounded by membrane and are enzymatically active based on cell-tracker incorporation. Their size is consistent with previously reported large oncosomes and apoptotic bodies. We demonstrate that these melanoma-derived vesicular-bodies rapidly affect brain endothelial barrier integrity, measured using ECIS biosensor technology, where the disruption is evident within ~60 min. This disruption involves acquisition of the vesicles through transcellular uptake into the endothelial cells. We also observed extensive actin-rearrangement, actin removal from the paracellular boundary of the endothelial cells and envelopment of the vesicular-bodies by actin. This was concordant with widespread changes in CD144 localisation, which was consistent with the loss of junctional strength. High-resolution confocal imaging revealed proximity of the melanoma vesicular-bodies juxtaposed to the endothelial nucleus, often containing fragmented DNA themselves, raising speculation over this association and potential delivery of nuclear material into the brain endothelial cells. The disruption of the endothelial cells occurs in a manner that is faster and completely distinct to that of invasion by intact melanoma cells. Given the clinical observation of large vesicles in the circulation of melanoma patients by others, we hypothesize their involvement in weakening or priming the brain vasculature for melanoma invasion.

Resveratrol nanoparticle attenuates metastasis and angiogenesis by deregulating inflammatory cytokines through inhibition of CAFs in oral cancer by CXCL-12/IL-6-dependent pathway

Cancer-associated fibroblasts (CAFs) are one of the highly abundant components in the tumor microenvironment (TME). They secrete several cytokines, which amplified tumor progression, invasion, stemness, metastasis, and angiogenesis. Here, we evaluate the potentiality of cytokines for the formation of cancer stem cells (CSCs) in oral cancer cells niche and investigate the anti-inflammatory and anti-carcinogenic effect of Resveratrol-nanoparticle (Res-NP). We first differentiated quiescent human fibroblasts into CAFs in vitro in response to PDGF-B and TGF-β stimulation and these CAFs were found to increase CXCL-12 and IL-6 secretion. CSCs-enriched population was created by incubating H-357 cells with CAFs and cytokine-enriched CAFs-conditioned media (CAFs-CM). Likewise, CSCs-populated environment was also generated after incubating CAFs-CM to patient-derived primary oral cancer cells. It was noted that CXCL-12 and IL-6 secreted from CAFs significantly promoted CSCs growth, proliferation, aggressiveness, metastasis, and angiogenesis. However, Res-NP reduced CSCs growth and proliferation by abrogating the secretion of CXCL-12 and IL-6. A significant decrease in the expression of metastatic and angiogenic markers, in ovo blood vascularization, intracellular NO generation, MMPs expression and tube formation was found upon Res-NP treatment. Reduction of representative CSCs and angiogenesis markers were also noted after Res-NP treatment in xenograft mice model. CXCL-12 physically interact with IL-6 and this interaction was diminished after Res-NP treatment. Moreover, the expression of CD133 and VEGF-A were down-regulated either on Res-NP or CXCL-12/IL-6-specific inhibitors treated CSCs-enriched cells. Thus, the data suggest that CSCs growth is CXCL-12 and IL-6 dependent and Res-NP obstruct carcinogenesis and metastasis by inhibiting CXCL-12 and IL-6 production in in vitro, in vivo, in ovo, and ex vivo systems.

Effects of oxygen on the response of mitochondria to X-irradiation and reactive oxygen species-mediated fibroblast activation

PURPOSE

In living organisms, sensitivity to radiation increases in the presence of oxygen (O₂) compared with that under anoxic or hypoxic conditions. Here, we investigated whether O₂ concentration affected the response of mitochondria to X-rays radiation, which is associated with tumor microenvironment formation via fibroblast activation in radiation-related tumors.

MATERIALS AND METHODS

O₂ concentrations were controlled at <5% (internal environmental oxygen condition) or anoxic levels during culture of normal human diploid lung fibroblasts TIG-3 and MRC-5. Protein expression associated with the response of mitochondria to radiation was assessed using immunostaining or western blotting.

RESULTS

Induction of DNA damage (marker: γ-H2A histone family member X) and mitochondrial signaling (AMP-activated protein kinase), suppression of mitochondrial metabolic activity, and generation of reactive oxygen species occurred with radiation in cells cultured under 5% and 20% O₂ conditions. However, reducing O₂ concentration mitigated the effects of radiation on cell growth, mitochondrial damage (parkin), induction of antioxidant responses (nuclear factor E2-related factor 2), and fibroblast activation (α-smooth muscle actin). Radiation did not affect the markers used in this study in the absence of O₂.

CONCLUSION

O₂ concentration affected the response of mitochondria to radiation and reactive oxygen species-mediated fibroblast activation. Higher O₂ concentrations enhanced the effects of radiation on mitochondria in human fibroblasts. In vitro studies may overestimate in vivo radiation effects due to high O₂ concentrations.

Clinical Trial in a Dish for Space Radiation Countermeasure Discovery

NASA aims to return humans to the moon within the next five years and to land humans on Mars in a few decades. Space radiation exposure represents a major challenge to astronauts' health during long-duration missions, as it is linked to increased risks of cancer, cardiovascular dysfunctions, central nervous system (CNS) impairment, and other negative outcomes. Characterization of radiation health effects and developing corresponding countermeasures are high priorities for the preparation of long duration space travel. Due to limitations of animal and cell models, the development of novel physiologically relevant radiation models is needed to better predict these individual risks and bridge gaps between preclinical testing and clinical trials in drug development. "Clinical Trial in a Dish" (CTiD) is now possible with the use of human induced pluripotent stem cells (hiPSCs), offering a powerful tool for drug safety or efficacy testing using patient-specific cell models. Here we review the development and applications of CTiD for space radiation biology and countermeasure studies, focusing on progress made in the past decade.

Scalable Production of Extracellular Vesicles and Its Therapeutic Values: A Review

Extracellular vesicles (EVs) are minute vesicles with lipid bilayer membranes. EVs are secreted by cells for intercellular communication. Recently, EVs have received much attention, as they are rich in biological components such as nucleic acids, lipids, and proteins that play essential roles in tissue regeneration and disease modification. In addition, EVs can be developed as vaccines against cancer and infectious diseases, as the vesicle membrane has an abundance of antigenic determinants and virulent factors. EVs for therapeutic applications are typically collected from conditioned media of cultured cells. However, the number of EVs secreted by the cells is limited. Thus, it is critical to devise new strategies for the large-scale production of EVs. Here, we discussed the strategies utilized by researchers for the scalable production of EVs. Techniques such as bioreactors, mechanical stimulation, electrical stimulation, thermal stimulation, magnetic field stimulation, topographic clue, hypoxia, serum deprivation, pH modification, exposure to small molecules, exposure to nanoparticles, increasing the intracellular calcium concentration, and genetic modification have been used to improve the secretion of EVs by cultured cells. In addition, nitrogen cavitation, porous membrane extrusion, and sonication have been utilized to prepare EV-mimetic nanovesicles that share many characteristics with naturally secreted EVs. Apart from inducing EV production, these upscaling interventions have also been reported to modify the EVs' cargo and thus their functionality and therapeutic potential. In summary, it is imperative to identify a reliable upscaling technique that can produce large quantities of EVs consistently. Ideally, the produced EVs should also possess cargo with improved therapeutic potential.

Blue light irradiation inhibits the growth of colon cancer and activation of cancer‑associated fibroblasts

Irradiation with a specific wavelength of light using light‑emitting diodes (LEDs) has various effects on cells and organisms. Recently, the antitumor effects of visible blue light on tumor cells were reported; however, the mechanism and effects on the tumor microenvironment remain unclear. Human colon cancer cells (HCT‑116) were injected into the rectal wall of nude mice. Tumors were irradiated with a 465‑nm LED light at 30 mW/cm² for 30 min. Tumor volumes and the expression levels of opsin 3 (Opn3), autophagy‑related factors, cancer‑associated fibroblast (CAF) markers, and programmed cell death 1‑ligand (PD‑L1) were measured. Additionally, human intestinal fibroblasts were cultured in HCT116‑conditioned medium (CM) to prepare CAFs. CAFs were divided into an LED group and a control group, and the effect of the LED light on CAF activation in colon cancer cells was examined. Irradiation with blue LED light suppressed tumor growth; Opn3 expression was localized to the cell membrane in the LED group. Irradiated tumors exhibited increased autophagy‑related gene expression. Furthermore, in the LED group, TGF‑β and α‑SMA expression levels in the fibroblasts were decreased. Regarding CAFs, α‑SMA and IL‑6 expression levels were decreased in the LED group. HCT‑116 cells cultured in CAF‑CM with LED irradiation showed no enhanced migration or invasion. In the HCT‑116 cells cultured in CM of CAFs irradiated with LED, the relative increase in PD‑L1 expression was lower than that noted in the CAF‑CM without LED irradiation. Blue LED light may have a direct antitumor effect on colon cancer and also an inhibitory effect on CAFs.

Immunobiology of cancer-associated fibroblasts in the context of radiotherapy

Radiotherapy (RT) still represents a mainstay of treatment in clinical oncology. Traditionally, the effectiveness of radiotherapy has been attributed to the killing potential of ionizing radiation (IR) over malignant cells, however, it has become clear that therapeutic efficacy of RT also involves activation of innate and adaptive anti-tumor immune responses. Therapeutic irradiation of the tumor microenvironment (TME) provokes profound cellular and biological reconfigurations which ultimately may influence immune recognition. As one of the major constituents of the TME, cancer-associated fibroblasts (CAFs) play central roles in cancer development at all stages and are recognized contributors of tumor immune evasion. While some studies argue that RT affects CAFs negatively through growth arrest and impaired motility, others claim that exposure of fibroblasts to RT promotes their conversion into a more activated phenotype. Nevertheless, despite the well-described immunoregulatory functions assigned to CAFs, little is known about the interplay between CAFs and immune cells in the context of RT. In this review, we go over current literature on the effects of radiation on CAFs and the influence that CAFs have on radiotherapy outcomes, and we summarize present knowledge on the transformed cellular crosstalk between CAFs and immune cells after radiation.

Cancer-associated fibroblasts in non-small cell lung cancer: Recent advances and future perspectives

Non-small cell lung cancer (NSCLC) constitutes the majority of lung cancer, which is the leading cause of cancer-related deaths in the world. Nearly 70% of NSCLC patients were diagnosed at advanced stage with only 15% of five-year survival rate. Cancer-associated fibroblasts (CAFs) are the major component of tumor microenvironment and account for almost 70% of the cells in tumor tissues. By the crosstalk with cancer cells, CAFs reprogrammed cancer cell metabolism, remodeled extracellular matrix (ECM) and created a supportive niche for cancer stem cells. CAFs lead collective invasion of tumor cells and shape tumor immune microenvironment, promoting tumor metastasis and immune escape. In this review, we have summarized the progress of studies regarding CAFs influences on NSCLC in recent five years from the aspects of cell growth, metabolism, therapy resistance, invasion and metastasis and immune suppression. We have discussed the involved mechanisms and implications for the development of anti-NSCLC therapies. The current strategies of CAFs targeting and elimination have also been generalized. Only better understanding of the molecular biology of CAFs may contribute to the development of novel anti-NSCLC strategies.