Hypoxic lung cancer cell-derived exosomal miR-21 mediates macrophage M2 polarization and promotes cancer cell proliferation through targeting IRF1

miRNA-21, an oncomiR that regulates cell proliferation, migration, invasion and therapy response in lung cancer

Lung cancer is the leading cause of cancer-related death globally, with poor survival rates due mostly to a lack of early detection. The usual diagnostic technique includes a biopsy, which is frequently performed later in the disease's progression. In order to uncover processes that improve illness detection and prognosis, miRNA-21 emerges as a major miRNA identified in a variety of cancer types, including lung cancer. This review compiles insights into the involvement of miRNA-21 within the distinct cellular processes underlying lung cancer. To achieve this, we conducted an extensive literature review, drawing from published in vitro, in vivo and clinical trials studies. Searches were performed in the PubMed, Scielo, CAPES Journal Portal, BVS, INCA, and Clinical Trials.Gov. Only English written articles were selected. As screening criteria, we selected articles that explored the modulation pathways of miRNA-21, along with the proteins and genes implicated in tumorigenesis, metastasis, therapy resistance to established treatments, and their significance in the diagnosis and prognosis of lung cancer. A total of 3294 articles were identified, and 37 papers were selected to compose the review, after analysing selection criteria. Of these, 57 % studies presented in vitro evaluation, 22 % studies showed in vivo analysis, and 12 clinical trials were found. This study elucidates the principal signaling pathways influenced by miRNA-21, which play a pivotal role in lung cancer development. This comprehensive review sheds light on the potential significance of miRNA-21 as a critical mechanism for improving the prognosis of lung cancer patients, facilitating the transition of experimental data into the clinical phase. Therefore, we summarized published articles of miRNA-21 modulated signal pathways in lung cancer.

The cellular-centered view of hypoxia tumor microenvironment: Molecular mechanisms and therapeutic interventions

Cancer is a profoundly dynamic, heterogeneous and aggressive systemic ailment, with a coordinated evolution of various types of tumor niches. Hypoxia plays an indispensable role in the tumor micro-ecosystem, drastically enhancing the plasticity of cancer cells, fibroblasts and immune cells and orchestrating intercellular communication. Hypoxia-induced signals, particularly hypoxia-inducible factor-1α (HIF-1α), drive the reprogramming of genetic, transcriptional, and proteomic profiles. This leads to a spectrum of interconnected processes, including augmented survival of cancer cells, evasion of immune surveillance, metabolic reprogramming, remodeling of the extracellular matrix, and the development of resistance to conventional therapeutic modalities like radiotherapy and chemotherapy. Here, we summarize the latest research on the multifaceted effects of hypoxia, where a multitude of cellular and non-cellular elements crosstalk with each other and co-evolve in a synergistic manner. Additionally, we investigate therapeutic approaches targeting hypoxic niche, encompassing hypoxia-activated prodrugs, HIF inhibitors, nanomedicines, and combination therapies. Finally, we discuss some of the issues to be addressed and highlight the potential of emerging technologies in the treatment of cancer.

Extracellular vesicles and macrophages in tumor microenvironment: Impact on cervical cancer

Cervical cancer is a serious threat to women's health. Extracellular vesicles exist in most body fluids for communication between organisms, having different effects on the occurrence, development, angiogenesis, and metastasis of cervical cancer, and are expected to become new targets for treatment. Macrophages are natural immune systems closely linked to the development of cervical cancer. In recent years, an increasing number of studies have confirmed the role of extracellular vesicles and macrophages in the gynecologic tumor environment. This article reviews the mechanism of action and application prospects of extracellular vesicles and macrophages in the cervical cancer microenvironment. In addition, the relationship between extracellular vesicles and macrophages from different sources is described, which provides ideas for the diagnosis and treatment of cervical cancer.

Hypoxia-Driven Changes in Tumor Microenvironment: Insights into Exosome-Mediated Cell Interactions

Hypoxia, as a prominent feature of the tumor microenvironment, has a profound impact on the multicomponent changes within this environment. Under hypoxic conditions, the malignant phenotype of tumor cells, the variety of cell types within the tumor microenvironment, as well as intercellular communication and material exchange, undergo complex alterations. These changes provide significant prospects for exploring the mechanisms of tumor development under different microenvironmental conditions and for devising therapeutic strategies. Exosomes secreted by tumor cells and stromal cells are integral components of the tumor microenvironment, serving as crucial mediators of intercellular communication and material exchange, and have consequently garnered increasing attention from researchers. This review focuses on the mechanisms by which hypoxic conditions promote the release of exosomes by tumor cells and alter their encapsulated contents. It also examines the effects of exosomes derived from tumor cells, immune cells, and other cell types under hypoxic conditions on the tumor microenvironment. Additionally, we summarize current research progress on the potential clinical applications of exosomes under hypoxic conditions and propose future research directions in this field.

Shaping the immune-suppressive microenvironment on tumor-associated myeloid cells through tumor-derived exosomes

Tumor-associated myeloid cells (TAMCs) play a crucial role in orchestrating the dynamics of the tumor immune microenvironment. This heterogeneous population encompasses myeloid-derived suppressor cells, tumor-associated macrophages and dendritic cells, all of which contribute to the establishment of an immunosuppressive milieu that fosters tumor progression. Tumor-derived exosomes (TEXs), small extracellular vesicles secreted by tumor cells, have emerged as central mediators in intercellular communication within the tumor microenvironment. In this comprehensive review, we explore the intricate mechanisms through which TEXs modulate immune-suppressive effects on TAMCs and their profound implications in cancer progression. We delve into the multifaceted ways in which TEXs influence TAMC functions, subsequently affecting tumor immune evasion. Furthermore, we elucidate various therapeutic strategies aimed at targeting TEX-mediated immune suppression, with the ultimate goal of bolstering antitumor immunity.

Non-coding RNAs and exosomal non-coding RNAs in lung cancer: insights into their functions

Lung cancer is the second most common form of cancer worldwide Research points to the pivotal role of non-coding RNAs (ncRNAs) in controlling and managing the pathology by controlling essential pathways. ncRNAs have all been identified as being either up- or downregulated among individuals suffering from lung cancer thus hinting that they may play a role in either promoting or suppressing the spread of the disease. Several ncRNAs could be effective non-invasive biomarkers to diagnose or even serve as effective treatment options for those with lung cancer, and several molecules have emerged as potential targets of interest. Given that ncRNAs are contained in exosomes and are implicated in the development and progression of the malady. Herein, we have summarized the role of ncRNAs in lung cancer. Moreover, we highlight the role of exosomal ncRNAs in lung cancer.

Tumor-derived extracellular vesicles regulate macrophage polarization: role and therapeutic perspectives

Extracellular vesicles (EVs) are important cell-to-cell communication mediators. This paper focuses on the regulatory role of tumor-derived EVs on macrophages. It aims to investigate the causes of tumor progression and therapeutic directions. Tumor-derived EVs can cause macrophages to shift to M1 or M2 phenotypes. This indicates they can alter the M1/M2 cell ratio and have pro-tumor and anti-inflammatory effects. This paper discusses several key points: first, the factors that stimulate macrophage polarization and the cytokines released as a result; second, an overview of EVs and the methods used to isolate them; third, how EVs from various cancer cell sources, such as hepatocellular carcinoma, colorectal carcinoma, lung carcinoma, breast carcinoma, and glioblastoma cell sources carcinoma, promote tumor development by inducing M2 polarization in macrophages; and fourth, how EVs from breast carcinoma, pancreatic carcinoma, lungs carcinoma, and glioblastoma cell sources carcinoma also contribute to tumor development by promoting M2 polarization in macrophages. Modified or sourced EVs from breast, pancreatic, and colorectal cancer can repolarize M2 to M1 macrophages. This exhibits anti-tumor activities and offers novel approaches for tumor treatment. Therefore, we discovered that macrophage polarization to either M1 or M2 phenotypes can regulate tumor development. This is based on the description of altering macrophage phenotypes by vesicle contents.

Exosomes: efficient macrophage-related immunomodulators in chronic lung diseases

Macrophages, the predominant immune cells in the lungs, play a pivotal role in maintaining the delicate balance of the pulmonary immune microenvironment. However, in chronic inflammatory lung diseases and lung cancer, macrophage phenotypes undergo distinct transitions, with M1-predominant macrophages promoting inflammatory damage and M2-predominant macrophages fostering cancer progression. Exosomes, as critical mediators of intercellular signaling and substance exchange, participate in pathological reshaping of macrophages during development of pulmonary inflammatory diseases and lung cancer. Specifically, in inflammatory lung diseases, exosomes promote the pro-inflammatory phenotype of macrophages, suppress the anti-inflammatory phenotype, and subsequently, exosomes released by reshaped macrophages further exacerbate inflammatory damage. In cancer, exosomes promote pro-tumor tumor-associated macrophages (TAMs); inhibit anti-tumor TAMs; and exosomes released by TAMs further enhance tumor proliferation, metastasis, and resistance to chemotherapy. Simultaneously, exosomes exhibit a dual role, holding the potential to transmit immune-modulating molecules and load therapeutic agents and offering prospects for restoring immune dysregulation in macrophages during chronic inflammatory lung diseases and lung cancer. In chronic inflammatory lung diseases, this is manifested by exosomes reshaping anti-inflammatory macrophages, inhibiting pro-inflammatory macrophages, and alleviating inflammatory damage post-reshaping. In lung cancer, exosomes reshape anti-tumor macrophages, inhibit pro-tumor macrophages, and reshaped macrophages secrete exosomes that suppress lung cancer development. Looking ahead, efficient and targeted exosome-based therapies may emerge as a promising direction for treatment of pulmonary diseases.

Tumorigenic and tumoricidal properties of exosomes in cancers; a forward look

In recent decades, emerging data have highlighted the critical role of extracellular vesicles (EVs), especially (exosomes) Exos, in the progression and development of several cancer types. These nano-sized vesicles are released by different cell lineages within the cancer niche and maintain a suitable platform for the interchange of various signaling molecules in a paracrine manner. Based on several studies, Exos can transfer oncogenic factors to other cells, and alter the activity of immune cells, and tumor microenvironment, leading to the expansion of tumor cells and metastasis to the remote sites. It has been indicated that the cell-to-cell crosstalk is so complicated and a wide array of factors are involved in this process. How and by which mechanisms Exos can regulate the behavior of tumor cells and non-cancer cells is at the center of debate. Here, we scrutinize the molecular mechanisms involved in the oncogenic behavior of Exos released by different cell lineages of tumor parenchyma. Besides, tumoricidal properties of Exos from various stem cell (SC) types are discussed in detail.

Roles of Interferon Regulatory Factor 1 in Tumor Progression and Regression: Two Sides of a Coin

IRF1 is a transcription factor well known for its role in IFN signaling. Although IRF1 was initially identified for its involvement in inflammatory processes, there is now evidence that it provides a function in carcinogenesis as well. IRF1 has been shown to affect several important antitumor mechanisms, such as induction of apoptosis, cell cycle arrest, remodeling of tumor immune microenvironment, suppression of telomerase activity, suppression of angiogenesis and others. Nevertheless, the opposite effects of IRF1 on tumor growth have also been demonstrated. In particular, the "immune checkpoint" molecule PD-L1, which is responsible for tumor immune evasion, has IRF1 as a major transcriptional regulator. These and several other properties of IRF1, including its proposed association with response and resistance to immunotherapy and several chemotherapeutic drugs, make it a promising object for further research. Numerous mechanisms of IRF1 regulation in cancer have been identified, including genetic, epigenetic, transcriptional, post-transcriptional, and post-translational mechanisms, although their significance for tumor progression remains to be explored. This review will focus on the established tumor-suppressive and tumor-promoting functions of IRF1, as well as the molecular mechanisms of IRF1 regulation identified in various cancers.

Mechanism of gambogic acid repressing invasion and metastasis of colorectal cancer by regulating macrophage polarization via tumor cell-derived extracellular vesicle-shuttled miR-21

Colorectal cancer (CRC) is a major cause of mortality and morbidity. Gambogic acid (GA) is a promising antitumor drug for treating CRC. We aimed to elucidate its mechanism in CRC invasion/metastasis via tumor cell-derived extracellular vesicle (EV)-carried miR-21. Nude mice peritoneal carcinomatosis (PC) model was subjected to GA treatment liver collection, followed by observation/counting of metastatic liver tissues/liver metastatic nodules by hematoxylin and eosin staining. miR-21 expression in metastatic liver tissues/CD68 + CD86, CD68 + CD206 cell percentages and M2 macrophage marker CD206 level in tumor tissues/interleukin (IL)-12 and IL-10 levels were determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR)/flow cytometry/enzyme-linked immunosorbent assay. HT-29 cells were treated with GA/miR-21 mimics/negative control for 48 h. miR-21 expression/cell proliferation/migration/invasion/apoptosis were assessed by RT-qPCR/cell counting kit-8/scratch assay/transwell assay/flow cytometry. EVs were extracted from HT-29 cells and identified by transmission electron microscope/nanoparticle tracking analysis/Western blot. IL-4/IL-13-induced macrophages/PC nude mice were treated with GA and EVs, with the internalization of EVs by macrophages assessed through the uptake test. After intraperitoneal injection of GA, PC nude mice exhibited decreased tumor cell density/irregular cell number/liver metastatic nodule number/miR-21 expression, and CRC cells manifested reduced CD68 + CD206 cells/IL-10/miR-21/proliferation/migration/invasion and increased CD68 + CD86 cells/IL-12/apoptosis, while these trends were opposite after miR-21 overexpression, implying that GA curbed CRC/cell invasion/metastasis and macrophage polarization by diminishing miR-21 levels. miR-21 was encapsulated in HT-29 cell-derived EVs. M2 polarization elevated CD206 cells/IL-10, which were decreased by simultaneous GA treatment. EVs could be uptaken by macrophages. CRC cell-EV-miR-21 annulled the suppression effects of GA on macrophage M2 polarization. GA suppressed macrophage M2 polarization by lessening tumor cell derived-EV-shuttled miR-21, thereby weakening CRC invasion/metastasis.

Pancreatic cancer stem cell-derived exosomal miR-210 mediates macrophage M2 polarization and promotes gemcitabine resistance by targeting FGFRL1

Pancreatic cancer (PC) is a serious threat to human health, with most patients diagnosed at the advanced stages of the disease. Treatment with gemcitabine (GEM) leads to PC GEM resistance. In addition, cancer stem cell (CSC)-derived exosomes play an important role in cancer progression. We aimed to investigate the role and mechanism of action of PC stem cell-derived exosomes in PC drug resistance and progression. CSC-derived exosomes increased the proportion of F4/80+/CD86 + cells and levels of M2 polarization factors. miR-210 is expressed in CSC-derived exosomes. Thus, following co-culture, miR-210 was taken up by macrophages. Transfection or the addition of miR-210 mimics increased the proportion of F4/80+/CD206 + cells and levels of M2 polarization factors. Further, the miR-210 targets inhibited the levels of FGFRL1. The FGFRL1 overexpression plasmid also inhibited miR-210-mediated M2 polarization. After co-culture of THP-M2 cells with PC cells and treatment with GEM, the survival rate, migration rate, and levels of MDR, YB-1, BCRP, p-PI3K, p-AKT, and p-mTOR in PC cells increased. And THP-M2 increased the tumor volume and MDR, YB-1, BCRP, p-PI3K, p-AKT, and p-mTOR levels. Overall, miR-210 from PC stem cell-derived exosome targets and inhibits FGFRL1 to promote macrophage M2 polarization, which activates the p-PI3K/p-AKT/p-mTOR pathway and increases GEM resistance.

Hypoxic regulation of extracellular vesicles: Implications for cancer therapy

Extracellular vesicles (EVs) play a pivotal role in intercellular communication and have been implicated in cancer progression. Hypoxia, a pervasive hallmark of cancer, is known to regulate EV biogenesis and function. Hypoxic EVs contain a specific set of proteins, nucleic acids, lipids, and metabolites, capable of reprogramming the biology and fate of recipient cells. Enhancing the intrinsic therapeutic efficacy of EVs can be achieved by strategically modifying their structure and contents. Moreover, the use of EVs as drug delivery vehicles holds great promise for cancer treatment. However, various hurdles must be overcome to enable their clinical application as cancer therapeutics. In this review, we aim to discuss the current knowledge on the hypoxic regulation of EVs. Additionally, we will describe the underlying mechanisms by which EVs contribute to cancer progression in hypoxia and outline the progress and limitations of hypoxia-related EV therapeutics for cancer.

The macrophage polarization by miRNAs and its potential role in the treatment of tumor and inflammation (Review)

The characteristics of monocyte/macrophage lineage are diversity and plasticity, mainly manifested by M1 and M2 subtypes in the body tissues, and playing different roles in the immunity. In the polarization process of macrophages, the classic molecular mechanism is related to sequential transcription factors. Whether in tumor or inflammatory local microenvironment, the pathological factors of the local microenvironment often affect the polarization of M1 and M2 macrophages, and participate in the occurrence and development of these pathological processes. In recent years, a growing number of research results demonstrated that non‑coding RNA (ncRNA) also participates in the polarization process of macrophages, in addition to traditional cytokines and transcriptional regulation signal pathway molecules. Among numerous ncRNAs, microRNAs (miRNAs) have attracted more attention from scholars both domestically and internationally, and significant progress has been made in basic and clinical research. Therefore, for improved understanding of the molecular mechanism of miRNAs in macrophage polarization and analysis of the potential value of this regulatory pathway in tumor and inflammatory intervention therapy, a comprehensive review of the progress of relevant literature research was conducted and some viewpoints and perspectives were proposed.

Exosomal miRNAs assist in the crosstalk between tumor cells and immune cells and its potential therapeutics

Exosomes are small extracellular vesicles that carry active substances (including proteins, lipids, and nucleic acids) and are essential for homeostasis and signal transmission. Recent studies have focused on the function of exosomal miRNAs in tumor progression. Researchers have expanded the use of exosomes and miRNAs as potential therapeutic tools and biomarkers to detect tumor progression. Immune cells, as an important part of the tumor microenvironment (TME), secrete a majority of exosome-derived miRNAs involved in the biological processes of malignancies. However, the underlying mechanisms remain unclear. Currently, there is no literature that systematically summarizes the communication of exosome-derived miRNAs between tumor cells and immune cells. Based on the cell specificity of exosome-derived miRNAs, this review provides the first comprehensive summary of the significant miRNAs from the standpoint of exosome sources, which are tumor cells and immune cells. Furthermore, we elaborated on the potential clinical applications of these miRNAs, attempting to propose existing difficulties and future possibilities in tumor diagnostics and therapy.

Potential targets of natural medicines: preventing lung cancer pre-metastatic niche formation by regulating exosomes

Lung cancer is one of the most devastating diseases worldwide with high incidence and mortality, and the incidence continues to rise. Metastasis is the leading cause of death in lung cancer patients, yet the molecular effectors underlying tumor dissemination remain poorly defined. Research findings in recent years confirmed primed microenvironment of future metastatic sites, called the pre-metastatic niche, is a prerequisite for overt metastasis. Exosomes have recently emerged as important players in pre-metastatic niche formation. Natural medicines have traditionally been rich sources of drug discovery. Some of them exhibit favorable anti-lung cancer activity. The review focused on the latest advances in the regulation of the pre-metastatic niche formation in lung cancer by the contents of exosomes of representative natural medicines. Additionally, the mechanism of natural medicines was summarized in detail, which would provide new insights for anti-cancer new drug development.

Potential Avenues for Exosomal Isolation and Detection Methods to Enhance Small-Cell Lung Cancer Analysis

Around the world, lung cancer has long been the main factor in cancer-related deaths, with small-cell lung cancer (SCLC) being the deadliest form of lung cancer. Cancer cell-derived exosomes and exosomal miRNAs are considered promising biomarkers for diagnosing and prognosis of various diseases, including SCLC. Due to the rapidity of SCLC metastasis, early detection and diagnosis can offer better diagnosis and prognosis and therefore increase the patient's chances of survival. Over the past several years, many methodologies have been developed for analyzing non-SCLC-derived exosomes. However, minimal advances have been made in SCLC-derived exosome analysis methodologies. This Review discusses the epidemiology and prominent biomarkers of SCLC. Followed by a discussion about the effective strategies for isolating and detecting SCLC-derived exosomes and exosomal miRNA, highlighting the critical challenges and limitations of current methodologies. Finally, an overview is provided detailing future perspectives for exosome-based SCLC research.

Potential Pathogenic Impact of Cow’s Milk Consumption and Bovine Milk-Derived Exosomal MicroRNAs in Diffuse Large B-Cell Lymphoma

Epidemiological evidence supports an association between cow’s milk consumption and the risk of diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin lymphoma worldwide. This narrative review intends to elucidate the potential impact of milk-related agents, predominantly milk-derived exosomes (MDEs) and their microRNAs (miRs) in lymphomagenesis. Upregulation of PI3K-AKT-mTORC1 signaling is a common feature of DLBCL. Increased expression of B cell lymphoma 6 (BCL6) and suppression of B lymphocyte-induced maturation protein 1 (BLIMP1)/PR domain-containing protein 1 (PRDM1) are crucial pathological deviations in DLBCL. Translational evidence indicates that during the breastfeeding period, human MDE miRs support B cell proliferation via epigenetic upregulation of BCL6 (via miR-148a-3p-mediated suppression of DNA methyltransferase 1 (DNMT1) and miR-155-5p/miR-29b-5p-mediated suppression of activation-induced cytidine deaminase (AICDA) and suppression of BLIMP1 (via MDE let-7-5p/miR-125b-5p-targeting of PRDM1). After weaning with the physiological termination of MDE miR signaling, the infant’s BCL6 expression and B cell proliferation declines, whereas BLIMP1-mediated B cell maturation for adequate own antibody production rises. Because human and bovine MDE miRs share identical nucleotide sequences, the consumption of pasteurized cow’s milk in adults with the continued transfer of bioactive bovine MDE miRs may de-differentiate B cells back to the neonatal “proliferation-dominated” B cell phenotype maintaining an increased BLC6/BLIMP1 ratio. Persistent milk-induced epigenetic dysregulation of BCL6 and BLIMP1 expression may thus represent a novel driving mechanism in B cell lymphomagenesis. Bovine MDEs and their miR cargo have to be considered potential pathogens that should be removed from the human food chain.

The Potential Use of Exosomes in Anti-Cancer Effect Induced by Polarized Macrophages

The rapid development of aberrant cells outgrowing their normal bounds, which can subsequently infect other body parts and spread to other organs-a process known as metastasis-is one of the significant characteristics of cancer. The main reason why cancer patients die is because of widespread metastases. This abnormal cell proliferation varies in cancers of over a hundred types, and their response to treatment can vary substantially. Several anti-cancer drugs have been discovered to treat various tumors, yet they still have harmful side-effects. Finding novel, highly efficient targeted therapies based on modifications in the molecular biology of tumor cells is essential to reduce the indiscriminate destruction of healthy cells. Exosomes, an extracellular vesicle, are promising as a drug carrier for cancer therapy due to their good tolerance in the body. In addition, the tumor microenvironment is a potential target to regulate in cancer treatment. Therefore, macrophages are polarized toward M1 and M2 phenotypes, which are involved in cancer proliferation and are malignant. It is evident from recent studies that controlled macrophage polarization might contribute to cancer treatment, by the direct way of using miRNA. This review provides an insight into the potential use of exosomes to develop an 'indirect', more natural, and harmless cancer treatment through regulating macrophage polarization.

Exosomal Non-Coding RNAs: Novel Regulators of Macrophage-Linked Intercellular Communication in Lung Cancer and Inflammatory Lung Diseases

Macrophages are innate immune cells and often classified as M1 macrophages (pro-inflammatory states) and M2 macrophages (anti-inflammatory states). Exosomes are cell-derived nanovesicles that range in diameter from 30 to 150 nm. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), are abundant in exosomes and exosomal ncRNAs influence immune responses. Exosomal ncRNAs control macrophage-linked intercellular communication via their targets or signaling pathways, which can play positive or negative roles in lung cancer and inflammatory lung disorders, including acute lung injury (ALI), asthma, and pulmonary fibrosis. In lung cancer, exosomal ncRNAs mediated intercellular communication between lung tumor cells and tumor-associated macrophages (TAMs), coordinating cancer proliferation, migration, invasion, metastasis, immune evasion, and therapy resistance. In inflammatory lung illnesses, exosomal ncRNAs mediate macrophage activation and inflammation to promote or inhibit lung damage. Furthermore, we also discussed the possible applications of exosomal ncRNA-based therapies for lung disorders.

MiR-21 Is Induced by Hypoxia and Down-Regulates RHOB in Prostate Cancer

Tumour hypoxia is a well-established contributor to prostate cancer progression and is also known to alter the expression of several microRNAs. The over-expression of microRNA-21 (miR-21) has been consistently linked with many cancers, but its role in the hypoxic prostate tumour environment has not been well studied. In this paper, the link between hypoxia and miR-21 in prostate cancer is investigated. A bioinformatic analysis of The Cancer Genome Atlas (TCGA) prostate biopsy datasets shows the up-regulation of miR-21 is significantly associated with prostate cancer and clinical markers of disease progression. This up-regulation of miR-21 expression was shown to be caused by hypoxia in the LNCaP prostate cancer cell line in vitro and in an in vivo prostate tumour xenograft model. A functional enrichment analysis also revealed a significant association of miR-21 and its target genes with processes related to cellular hypoxia. The over-expression of miR-21 increased the migration and colony-forming ability of RWPE-1 normal prostate cells. In vitro and in silico analyses demonstrated that miR-21 down-regulates the tumour suppressor gene Ras Homolog Family Member B (RHOB) in prostate cancer. Further a TCGA analysis illustrated that miR-21 can distinguish between different patient outcomes following therapy. This study presents evidence that hypoxia is a key contributor to the over-expression of miR-21 in prostate tumours, which can subsequently promote prostate cancer progression by suppressing RHOB expression. We propose that miR-21 has good potential as a clinically useful diagnostic and prognostic biomarker of hypoxia and prostate cancer.

Role of exosomes in non-small cell lung cancer and EGFR-mutated lung cancer

As an important mediator of information transfer between cells, exosomes play a unique role in regulating tumor growth, supporting vascular proliferation, tumor invasion, and metastasis. Exosomes are widely present in various body fluids, and therefore they can be used as a potential tool for non-invasive liquid biopsy. The present study reviews the role of exosomes in liquid biopsy, tumor microenvironment formation, and epithelial-mesenchymal transition in non-small cell lung cancer (NSCLC). By targeting epidermal growth factor receptor (EGFR) therapy as a first-line treatment for patients with NSCLC, this study also briefly describes the occurrence of EGRF+ exosomes and the role of exosomes and their contents in non-invasive detection and potential therapeutic targets in EGFR-mutated lung cancer.

Tumor cell-derived exosomal microRNA-146a promotes non-small cell lung cancer cell invasion and proliferation by inhibiting M1 macrophage polarization

Background

Tumor-associated macrophages (TAMs) affects the outcomes of non-small cell lung cancer (NSCLC). NSCLC cells released exosomes to suppress the antitumor activity of TAMs. MiR-146a is a critical regulator in TAM polarization. We hypothesized that NSCLC cells released exosomal miR-146a to regulate TAM polarization and thus affected its antitumor activity.

Methods

We used H1299 cells-derived exosomes to stimulate THP-1 cells that was pretreated with phorbol 12-myristate 13-acetate (M0 macrophage). Flow cytometry and reverse transcription-quantitative polymerase chain reaction (PCR) were used to determine the polarization of macrophages. The conditioned medium of exosome-treated M0 cells was used to culture H1299 cells, and the Cell Counting Kit-8, Ki67, transwell and scratch wound assays were used to determine the biological behavior of H1299 cells. To investigate whether exosomal miR-146a regulates TAM macrophages through targeting tumor necrosis factor receptor-associated factor 6 (TRAF-6) and interleukin-1 receptor-associated kinase 1 (IRAK-1), we used small interfering RNA to knockdown the expressions of them.

Results

Upregulation of miR-146a inhibited M1 polarization and thus impaired the antitumor activity of TAMs. Exosomes released by H1299 cells can be taken by M0 macrophage, and they upregulated the expression of miR-146a in M0 macrophage. The exosome suppresses M1 polarization by exosomal miR-146a. TRAF-6 and IRAK-1 mediated the inhibitive effects of exosomal miR-146a on M1 polarization.

Conclusions

NSCLC cells released exosomal miR-146a to inhibit the expressions of TRAF-6 and IRAK-1 in TAMs, resulting in the impaired antitumor activity of TAMs. NSCLC cell-derived exosomal miR-146a represents a novel therapeutic target for NSCLC treatment.