The role of exosomes in colorectal cancer disease progression and response to therapy

Dual role of mesenchymal stem/stromal cells and their cell-free extracellular vesicles in colorectal cancer

Colorectal cancer (CRC) is one of the main causes of cancer-related deaths. However, the surgical control of the CRC progression is difficult, and in most cases, the metastasis leads to cancer-related mortality. Mesenchymal stem/stromal cells (MSCs) with potential translational applications in regenerative medicine have been widely researched for several years. MSCs could affect tumor development through secreting exosomes. The beneficial properties of stem cells are attributed to their cell-cell interactions as well as the secretion of paracrine factors in the tissue microenvironment. For several years, exosomes have been used as a cell-free therapy to regulate the fate of tumor cells in a tumor microenvironment. This review discusses the recent advances and current understanding of assessing MSC-derived exosomes for possible cell-free therapy in CRC.

Immune function of colon cancer associated miRNA and target genes

Introduction

Colon cancer is a complex disease that involves intricate interactions between cancer cells and theimmune microenvironment. MicroRNAs (miRNAs) have recently emerged as critical regulators of gene expression in cancer, including colon cancer. There is increasing evidence suggesting that miRNA dysregulation plays a crucial role in modulating the immune microenvironment of intestinal cancer. In particular, miRNAs regulate immune cell activation, differentiation, and function, as well as cytokine and chemokine production in intestinal cancer. It is urgent to fully investigate the potential role of intestinal cancer-related miRNAs in shaping the immune microenvironment.

Methods

Therefore, this paper aims to identify miRNAs that are potentially associated with colon cancer and regulate a large number of genes related to immune function. We explored the role of these genes in colon cancer patient prognosis, immune infiltration, and tumor purity based on data of 174 colon cancer patients though convolutional neural network, survival analysis and multiple analysis tools.

Results

Our findings suggest that miRNA regulated genes play important roles in CD4 memory resting cells, macrophages.M2, and Mast cell activated cells, and they are concentrated in the cytokinecytokine receptor interaction pathway.

Discussion

Our study enhances our understanding of the underlying mechanisms of intestinal cancer and provides new insights into the development of effective therapies. Additionally, identification of miRNA biomarkers could aid in diagnosis and prognosis, as well as guide personalized treatment strategies for patients with intestinal cancer.

Isolation and Characterization of Extracellular Vesicles in Human Bowel Lavage Fluid

Colorectal cancer (CRC) is the third most common cancer worldwide and is detected in late stages because of a lack of early and specific biomarkers. Tumors can release extracellular vesicles (EVs), which participate in different functions, such as carrying nucleic acids to target cells; promoting angiogenesis, invasion, and metastasis; and preparing an adequate tumor microenvironment. Finally, bowel lavage fluid (BLF) is a rarely used sample that is obtained during colonoscopy. It presents low variability and protein degradation, is easy to handle, and is representative of EVs from tumor cells due to proximity of the sample collection. This sample has potential as a research tool and possible biomarker source for CRC prognosis and monitoring. In this study, EVs were isolated from human BLF by ultracentrifugation, then characterized by transmission electron microscopy and atomic force microscopy. EV concentration was determined by nanoparticle tracking analysis, and tetraspanins were determined by Western blot, confirming correct EV isolation. RNA, DNA, and proteins were isolated from these EVs; RNA was used in real-time PCR, and proteins were used in an immunoblotting analysis, indicating that EV cargo is optimal for use and study. These results indicate that EVs from BLF can be a useful tool for CRC study and could be a source of biomarkers for the diagnosis and monitoring of CRC.

SERS spectroscopy with machine learning to analyze human plasma derived sEVs for coronary artery disease diagnosis and prognosis

Coronary artery disease (CAD) is one of the major cardiovascular diseases and represents the leading causes of global mortality. Developing new diagnostic and therapeutic approaches for CAD treatment are critically needed, especially for an early accurate CAD detection and further timely intervention. In this study, we successfully isolated human plasma small extracellular vesicles (sEVs) from four stages of CAD patients, that is, healthy control, stable plaque, non-ST-elevation myocardial infarction, and ST-elevation myocardial infarction. Surface-enhanced Raman scattering (SERS) measurement in conjunction with five machine learning approaches, including Quadratic Discriminant Analysis, Support Vector Machine (SVM), K-Nearest Neighbor, Artificial Neural network, were then applied for the classification and prediction of the sEV samples. Among these five approaches, the overall accuracy of SVM shows the best predication results on both early CAD detection (86.4%) and overall prediction (92.3%). SVM also possesses the highest sensitivity (97.69%) and specificity (95.7%). Thus, our study demonstrates a promising strategy for noninvasive, safe, and high accurate diagnosis for CAD early detection.

A Different Exosome Secretion Pattern Characterizes Patient-Derived Colorectal Cancer Multicellular Spheroids and Their Mouse Xenografts

Simple Summary

Exosomes have a role in tumorigenesis and metastatic dissemination, their material content and size being associated with poor prognosis of colorectal cancer (CRC). Our work aims to investigate their secretion patterns in CRC stem cells in patient-derived multicellular tumor spheroids (MTSs) and their mouse xenografts, to unveil possible differences in terms of exosome amount, size, and secretion site between in vitro and in vivo models. Our results show that MTSs’ exosome secretion pattern depends on their structural complexity: few-layer spheroids show a lesser exosome secretion, limited to the apical domain of cancer cells; secretion increases in multilayered spheroids and is visible from apical and basolateral cancer cells domains. In xenograft models, exosome secretion occurs from all cancer cell domains, and it is quantitatively greater than that observed in spheroids. The influence of the surrounding environment of non-tumor cells may account for the difference in exosome secretion patterns between spheroids and xenografts.

Abstract

Up-to-date in vitro and in vivo preclinical models expressing the patient-specific cancer lineage responsible for CRC and its metastatic behavior and responsiveness to therapy are needed. Exosomes’ role in tumorigenesis and the metastatic process was demonstrated, and the material content and size of the exosomes are associated with a poor prognosis of CRC. Exosomes are generally imagined after their recovery from blood serum as isolated entities, and our work aims to investigate them “in situ” in their native environment by scanning and transmission electron microscopy to understand their secretion modalities. We studied CRC stem cells in patient-derived multicellular tumor spheroids (MTSs) and in their mouse xenograft to find possible differences in terms of exosome amount, size, and secretion site between in vitro and in vivo models. We observed that MTSs’ exosome secretion patterns depend on their structural complexity: few-layer MTSs show a lesser exosome secretion, limited to the apical domain of cancer cells, secretion increases in multilayered MTSs, and it develops from apical and basolateral cancer cells domains. In xenograft models, exosome secretion occurs from all cancer cell domains, and it is quantitatively greater than that observed in MTSs. This difference in exosome secretion pattern between MTSs and xenografts may be due to the influence of surrounding non-tumor cells.

2-methylpyridine-1-ium-1-sulfonate modifies tumor-derived exosome mediated macrophage polarization: Relevance to the tumor microenvironment

The compound "2-methylpyridine-1-ium-1-sulfonate" (MPS) is the active constituent of Allium hirtifolium Boiss. bulbs with potent anti-angiogenic and anti-cancer activities. Tumor microenvironment (TME) plays a key role in tumor progression via tumor derived exosome (TEX) mediated polarization of M2 type tumor associated macrophages (TAMs). In this study, we explored direct and colorectal cancer (CRC) exosome-mediated impacts of MPS on macrophage polarization to find out whether MPS could modify TEX in favor of anti-tumor M1-like macrophage polarization. After MPS isolation and characterization, first its direct anti-cancer effects were evaluated on HT-29 cells. Then, TEX were isolated from untreated (C-TEX) and MPS-treated (MPS-TEX) HT-29 cells. THP-1 M0 macrophages were incubated with MPS, C-TEX and MPS-TEX. Macrophage polarization was evaluated by flow cytometry, ELISA and gene expression analysis of several M1- and M2-related markers. MPS induced apoptosis and cell cycle arrest and reduced the migration ability of HT-29 cells. C-TEX polarized M0 macrophages toward a mixed M1-/M2-like phenotype with a high predominance of M2-like cells. Macrophage treatment with MPS was associated with the induction of M1-like phenotype. Also, MPS was demonstrated to ameliorate TEX-mediated effects in favor of M1-like polarization. In conclusion, our study addresses for the first time, the potential capability of MPS in skewing macrophages toward an anti-cancer M1-like phenotype both directly and in a TEX-dependent manner. Thus, in addition to its direct anti-cancer effects, this compound could also modify TME in favor of tumor eradication via its direct and TEX-mediated effects on macrophage polarization as a novel anti-cancer mechanism.

Use of Omics Technologies for the Detection of Colorectal Cancer Biomarkers

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers with high mortality rates, especially when detected at later stages. Early detection of CRC can substantially raise the 5-year survival rate of patients, and different efforts are being put into developing enhanced CRC screening programs. Currently, the faecal immunochemical test with a follow-up colonoscopy is being implemented for CRC screening. However, there is still a medical need to describe biomarkers that help with CRC detection and monitor CRC patients. The use of omics techniques holds promise to detect new biomarkers for CRC. In this review, we discuss the use of omics in different types of samples, including breath, urine, stool, blood, bowel lavage fluid, or tumour tissue, and highlight some of the biomarkers that have been recently described with omics data. Finally, we also review the use of extracellular vesicles as an improved and promising instrument for biomarker detection.

Exosomal-long non-coding RNAs journey in colorectal cancer: Evil and goodness faces of key players

Exosomes are nano-vesicles (NVs) secreted by cells and take part in cell-cell communications. Lately, these exosomes were proved to have dual faces in cancer. Actually, they can contribute to carcinogenesis through epithelial-mesenchymal transition (EMT), angiogenesis, metastasis and tumor microenvironment (TME) of various cancers, including colorectal cancer (CRC). On the other hand, they can be potential targets for cancer treatment. CRC is one of the most frequent tumors worldwide, with incidence rates rising in the recent decades. In its early stage, CRC is asymptomatic with poor treatment outcomes. Therefore, finding a non-invasive, early diagnostic biomarker tool and/or suitable defender to combat CRC is mandatory. Exosomes provide enrichment and safe setting for their cargos non-coding RNAs (ncRNAs) and proteins, whose expression levels can be upregulated ordown-regulated in cancer. Hence, exosomes can be used as diagnostic and/or prognostic tools for cancer. Moreover, exosomes can provide a novel potential therapeutic modality for tumors via loading with specific chemotherapeutic agents, with the advantage of possible tumor targeting. In this review, we will try to collect and address recent studies concerned with exosomes and their cargos' implications for CRC diagnosis and/or hopefully, treatment.

The Incredible Potential of Exosomes as Biomarkers in the Diagnosis of Colorectal Cancer

Colorectal cancer (CRC) is common cancer that is one of the leading causes of cancerrelated deaths around the world. The creation of new biomarkers for this disease is an important public health strategy for lowering the disease's mortality rate. According to new research, exosomes may be important sources of biomarkers in CRC. Exosomes are nanometer-sized membrane vesicles (30-200 nm) secreted by normal and cancer cells that transport RNA and proteins between cells and are thought to help with intercellular communication. Exosomes have been linked to CRC initiation and progression, and some differentially expressed RNAs and proteins in exosomes have been identified as potential cancer detection candidates. As a result, studying the relationship between exosomes and CRC may aid in the development of new biomarkers for the disease. This article discusses the importance of exosomes as biomarkers in the diagnosis of CRC, as well as their use in the treatment of CRC metastasis, chemoresistance, and recrudescence. The benefits and drawbacks of using exosomes as tumour markers are also discussed.

BRAFV600E mutant colorectal cancer cells mediate local immunosuppressive microenvironment through exosomal long noncoding RNAs

BACKGROUND

BRAF^V600E mutated colorectal cancer (CRC) is prone to peritoneal and distant lymph node metastasis and this correlates with a poor prognosis. The BRAF^V600E mutation is closely related to the formation of an immunosuppressive microenvironment. However, the correlation between BRAF^V600E mutation and changes in local immune microenvironment of CRC is not clear.

AIM

To explore the effect and mechanism of BRAF^V600E mutant on the immune microenvironment of CRC.

METHODS

Thirty patients with CRC were included in this study: 20 in a control group and 10 in a treatment group. The density of microvessels and microlymphatic vessels, and M2 subtype macrophages in tumor tissues were detected by immunohistochemistry. Screening and functional analysis of exosomal long noncoding RNAs (lncRNAs) were performed by transcriptomics. The proliferation and migration of human umbilical vein endothelial cells (HUVECs) and human lymphatic endothelial cells (HLECs) were detected by CCK-8 assay and scratch test, respectively. The tube-forming ability of endothelial cells was detected by tube formation assay. The macrophage subtypes were obtained by flow cytometry. The expression of vascular endothelial growth factor (VEGF)-A, basic fibroblast growth factor (bFGF), transforming growth factor (TGF)-β1, VEGF-C, claudin-5, occludin, zonula occludens (ZO)-1, fibroblast activation protein, and α-smooth muscle actin was assessed by western blot analysis. The levels of cytokines interleukin (IL)-6, TGF-β1, and VEGF were assessed by enzyme-linked immunosorbent assay.

RESULTS

BRAF^V600E mutation was positively correlated with the increase of preoperative serum carbohydrate antigen 19-9 (P < 0.05), and with poor tumor tissue differentiation in CRC (P < 0.01). Microvascular density and microlymphatic vessel density in BRAF^V600E mutant CRC tissues were higher than those in BRAF wild-type CRC (P < 0.05). The number of CD163⁺ M2 macrophages in BRAF^V600E mutant CRC tumor tissue was markedly increased (P < 0.05). Compared with exosomes from CRC cells with BRAF gene silencing, the expression of 13 lncRNAs and 192 mRNAs in the exosomes from BRAF^V600E mutant CRC cells was upregulated, and the expression of 22 lncRNAs and 236 mRNAs was downregulated (P < 0.05). The biological functions and signaling pathways predicted by differential lncRNA target genes and differential mRNAs were closely related to angiogenesis, tumor cell proliferation, differentiation, metabolism, and changes in the microenvironment. The proliferation, migration, and tube formation ability of HUVECs and HLECs induced by exosomes in the 1627 cell group (HT29 cells with BRAF gene silencing) was greatly reduced compared with the HT29 cell group (P < 0.05). Compared with the HT29 cell group, the expression levels of VEGF-A, bFGF, TGF-β1, and VEGF-C in the exosomes derived from 1627 cells were reduced. The expression of ZO-1 in HUVECs, and claudin-5, occludin, and ZO-1 in HLECs of the 1627 cell group was higher. Compared with the 1627 cell group, the exosomes of the HT29 cell group promoted the expression of CD163 in macrophages (P < 0.05). IL-6 secretion by macrophages in the HT29 cell group was markedly elevated (P < 0.05), whereas TGF-β1 was decreased (P < 0.05). The levels of IL-6, TGF-β1, and VEGF secreted by fibroblasts in the 1627 cell group decreased, compared with the HT29 cell group (P < 0.05).

CONCLUSION

BRAF^V600E mutant CRC cells can reach the tumor microenvironment by releasing exosomal lncRNAs, and induce the formation of an immunosuppressive microenvironment.

CRISPR/Cas13-Based Platforms for a Potential Next-Generation Diagnosis of Colorectal Cancer through Exosomes Micro-RNA Detection: A Review

Colorectal cancer (CRC) is the third most prevalent cancer with the second highest mortality rate worldwide. CRC is a heterogenous disease with multiple risk factors associated, including obesity, smoking, and use of alcohol. Of total CRC cases, 60% are diagnosed in late stages, where survival can drop to about 10%. CRC screening programs are based primarily on colonoscopy, yet this approach is invasive and has low patient adherence. Therefore, there is a strong incentive for developing molecular-based methods that are minimally invasive and have higher patient adherence. Recent reports have highlighted the importance of extracellular vesicles (EVs), specifically exosomes, as intercellular communication vehicles with a broad cargo, including micro-RNAs (miRNAs). These have been syndicated as robust candidates for diagnosis, primarily for their known activities in cancer cells, including immunoevasion, tumor progression, and angiogenesis, whereas miRNAs are dysregulated by cancer cells and delivered by cancer-derived exosomes (CEx). Quantitative polymerase chain reaction (qPCR) has shown good results detecting specific cancer-derived exosome micro-RNAs (CEx-miRNAs) associated with CRC, but qPCR also has several challenges, including portability and sensitivity/specificity issues regarding experiment design and sample quality. CRISPR/Cas-based platforms have been presented as cost-effective, ultrasensitive, specific, and robust clinical detection tools in the presence of potential inhibitors and capable of delivering quantitative and qualitative real-time data for enhanced decision-making to healthcare teams. Thereby, CRISPR/Cas13-based technologies have become a potential strategy for early CRC diagnosis detecting CEx-miRNAs. Moreover, CRISPR/Cas13-based platforms' ease of use, scalability, and portability also showcase them as a potential point-of-care (POC) technology for CRC early diagnosis. This study presents two potential CRISPR/Cas13-based methodologies with a proposed panel consisting of four CEx-miRNAs, including miR-126, miR-1290, miR-23a, and miR-940, to streamline novel applications which may deliver a potential early diagnosis and prognosis of CRC.

Dendritic Cell-Based Immunotherapies and their Potential use in Colorectal Cancer Immunotherapy

Dendritic cells (DCs) are professional antigen-presenting cells, which are resident or proliferating in organs. Major histocompatibility complex (MHC) Class I and II on DCs in normal steady conditions process and present antigens including cancer antigens. Many approaches are used to enhance antigen presentation process of DCs and capture cancer cells. DCs are harvested from cancer patients and manipulated ex vivo in DC-based cancer immunotherapy. In addition, DCs' vaccines and other anticancer therapy combinations were discussed to optimize DCs' efficiency for cancer immunotherapy. This review addressed the use of the human conventional type-1 DCs, OX40⁺ plasmacytoid DCs, and DCs-derived exosomes. In addition, different combinations with DCs therapy such as combination with the monoclonal antibody, cytokine-induced killer cells, adjuvants, chemotherapy (DCs-based chemoimmunotherapy), and nanoparticles were listed and explored for their effectiveness against cancer, and mainly against colorectal cancer.

Role of Stress-Survival Pathways and Transcriptomic Alterations in Progression of Colorectal Cancer: A Health Disparities Perspective

Every year, more than a million individuals are diagnosed with colorectal cancer (CRC) across the world. Certain lifestyle and genetic factors are known to drive the high incidence and mortality rates in some groups of individuals. The presence of enormous amounts of reactive oxygen species is implicated for the on-set and carcinogenesis, and oxidant scavengers are thought to be important in CRC therapy. In this review, we focus on the ethnicity-based CRC disparities in the U.S., the negative effects of oxidative stress and apoptosis, and gene regulation in CRC carcinogenesis. We also highlight the use of antioxidants for CRC treatment, along with screening for certain regulatory genetic elements and oxidative stress indicators as potential biomarkers to determine the CRC risk and progression.

Gradients in the in vivo intestinal stem cell compartment and their in vitro recapitulation in mimetic platforms

Intestinal tissue, and specifically its mucosal layer, is a complex and gradient-rich environment. Gradients of soluble factor (BMP, Noggin, Notch, Hedgehog, and Wnt), insoluble extracellular matrix proteins (laminins, collagens, fibronectin, and their cognate receptors), stromal stiffness, oxygenation, and sheer stress induced by luminal fluid flow at the crypt-villus axis controls and supports healthy intestinal tissue homeostasis. However, due to current technological challenges, very few of these features have so far been included in in vitro intestinal tissue mimetic platforms. In this review, the tightly defined and dynamic microenvironment of the intestinal tissue is presented in detail. Additionally, the authors introduce the current state-of-the-art intestinal tissue mimetic platforms, as well as the design drawbacks and challenges they face while attempting to capture the complexity of the intestinal tissue's physiology. Finally, the compositions of an "idealized" mimetic system is presented to guide future developmental efforts.

Exosomes: Their Role in Pathogenesis, Diagnosis and Treatment of Diseases

Simple Summary

The aim of this review is to provide an overview of the current scientific evidence concerning the role played by exosomes in the pathogenesis, diagnosis and treatment of diseases. The potential use of exosomes as delivery vectors for small-molecule therapeutic agents will be discussed. In addition, a special emphasis will be placed on the involvement of exosomes in oncological diseases, as well as to their potential therapeutic application as liquid biopsy tools mainly in cancer diagnosis. A better understanding of exosome biology could improve the results of clinical interventions using exosomes as therapeutic agents.

Abstract

Exosomes are lipid bilayer particles released from cells into their surrounding environment. These vesicles are mediators of near and long-distance intercellular communication and affect various aspects of cell biology. In addition to their biological function, they play an increasingly important role both in diagnosis and as therapeutic agents. In this paper, we review recent literature related to the molecular composition of exosomes, paying special attention to their role in pathogenesis, along with their application as biomarkers and as therapeutic tools. In this context, we analyze the potential use of exosomes in biomedicine, as well as the limitations that preclude their wider application.

Exosomal miR-193a and let-7g accelerate cancer progression on primary colorectal cancer and paired peritoneal metastatic cancer

A metastasis of colorectal cancer is difficult to diagnose, and has a poor prognosis. Therefore, we tried to elucidate the possibility of a diagnostic and prognostic marker. Exosomal miR-193a and let-7g were sorted by miRNA microarray. The expression of miR-193a in the PTM group was lower than that of the primary CRC group, and the expression of let-7g was higher than that of the primary CRC. MMP16 and CDKN1A expression was confirmed respectively for target genes of two miRNAs. When the mimics of these miRNAs were treated with cell lines, both MMP16 and CDKN1A decreased intracellular expression. Cell invasiveness and proliferation were decreased by miR-193a and increased by let-7g. The differences in expression of exosomal miR-193a and let-7g extracted from the plasma of patients were classified as cancer progression indicators. Furthermore, the survival rate decreased in the group with low miR-193a expression and high let-7g expression. Our study confirmed the possibility of using this as a diagnostic and prognostic marker for colorectal cancer by measuring the expression levels of exosomal miR-193a and let-7g in blood.