Exosomal transfer of miR-181b-5p confers senescence-mediated doxorubicin resistance via modulating BCLAF1 in breast cancer

Stem cell-derived extracellular vesicles as senotherapeutics

Cellular senescence (CS) is recognized as one of the hallmarks of aging, and an important player in a variety of age-related pathologies. Accumulation of senescent cells can promote a pro-inflammatory and pro-cancerogenic microenvironment. Among potential senotherapeutics are extracellular vesicles (EVs) (40-1000 nm), including exosomes (40-150 nm), that play an important role in cell-cell communications. Here, we review the most recent studies on the impact of EVs derived from stem cells (MSCs, ESCs, iPSCs) as well as non-stem cells of various types on CS and discuss potential mechanisms responsible for the senotherapeutic effects of EVs. The analysis revealed that (i) EVs derived from stem cells, pluripotent (ESCs, iPSCs) or multipotent (MSCs of various origin), can mitigate the cellular senescence phenotype both in vitro and in vivo; (ii) this effect is presumably senomorphic; (iii) EVs display cross-species activity, without apparent immunogenic responses. In summary, stem cell-derived EVs appear to be promising senotherapeutics, with a feasible application in humans.

Cancer-associated fibroblasts-secreted exosomal miR-92a-3p promotes tumor growth and stemness in hepatocellular carcinoma through activation of Wnt/β-catenin signaling pathway by suppressing AXIN1

Cancer-associated fibroblasts (CAFs) are a major cellular component in the tumor microenvironment and have been shown to exhibit protumorigenic effects in hepatocellular carcinoma (HCC). This study aimed to delve into the mechanisms underlying the tumor-promoting effects of CAFs in HCC. Small RNA sequencing was conducted to screen differential expressed microRNAs in exosomes derived from CAFs and normal fibroblasts (NFs). The miR-92a-3p expression was then measured using reverse transcriptase quantitative real-time PCR in CAFs, NFs, CAFs-derived exosomes (CAFs-Exo), and NF-derived exosomes (NFs-Exo). Compared to NFs or NF-Exo, CAFs and CAFs-Exo significantly promoted HCC cell proliferation, migration, and stemness. Additionally, compared to NFs or NF-Exo, miR-92a-3p level was notably higher in CAFs and CAFs-Exo, respectively. Exosomal miR-92a-3p was found to enhance HCC cell proliferation, migration, and stemness. Meanwhile, AXIN1 was targeted by miR-92a-3p. Exosomal miR-92a-3p could activate β-catenin/CD44 signaling in HCC cells by inhibiting AXIN1 messenger RNA. Furthermore, in vivo studies verified that exosomal miR-92a-3p notably promoted tumor growth and stemness through targeting AXIN1/β-catenin axis. Collectively, CAFs secreted exosomal miR-92a-3p was capable of promoting growth and stemness in HCC through activation of Wnt/β-catenin signaling pathway by suppressing AXIN1. Therefore, targeting CAFs-derived miR-92a-3p may be a potential strategy for treating HCC.

INHBA regulates Hippo signaling to confer 5-FU chemoresistance mediated by cellular senescence in colon cancer cells

Colon cancer has become a global public health challenge, and 5-Fluorouracil (5-FU) chemoresistance is a major obstacle in its treatment. Chemoresistance can be mediated by therapy-induced cellular senescence. This study intended to investigate mechanisms of INHBA (inhibin A) in 5-FU resistance mediated by cellular senescence in colon cancer. Bioinformatics analysis of INHBA expression in colon cancer tissues, survival analysis, and correlation analysis of cellular senescence markers were performed. The effects of INHBA on the biological characteristics and 5-FU resistance of colon cancer cells were examined through loss/gain-of-function and molecular assays. Finally, a xenograft mouse model was built to validate the mechanism of INHBA in vivo. INHBA was upregulated in colon cancer and was significantly positively correlated with cellular senescence markers uncoupling protein 2 (UCP-2), matrix metalloproteinase-1 (MMP-1), dense and erect panicle 1 (DEP1), and p21. Cellular senescence in colon cancer mediated 5-FU resistance. Downregulation of INHBA expression enhanced 5-FU sensitivity in colon cancer cells, inhibited cell proliferation, promoted apoptosis, increased the proportion of cells in G0/G1 phase, and it resulted in a lower proportion of senescent cells and lower levels of the cellular senescence markers interleukin 6 (IL-6) and interleukin 8 (IL-8). Analysis of whether to use the pathway inhibitor Verteporfin proved that INHBA facilitated colon cancer cell senescence and enhanced 5-FU chemoresistance via inactivation of Hippo signaling pathway, and consistent results were obtained in vivo. Collectively, INHBA conferred 5-FU chemoresistance mediated by cellular senescence in colon cancer cells through negative regulation of Hippo signaling.

A comprehensive guide to extract information from extracellular vesicles: a tutorial review towards novel analytical developments

In the medical field, extracellular vesicles (EVs) are gaining importance as they act as cells mediators. These are phospholipid bilayer vesicles and contain crucial biochemical information about their mother cells being carrier of different biomolecules such as small molecules, proteins, lipids, and nucleic acids. After release into the extracellular matrix, they enter the systemic circulation and can be found in all human biofluids. Since EVs reflect the state of the cell of origin, there is exponential attention as potential source of new circulating biomarkers for liquid biopsy. The use of EVs in clinical practice faces several challenges that need to be addressed: these include the standardization of lysis protocols, the availability of low-cost reagents and the development of analytical tools capable of detecting biomarkers. The process of lysis is a crucial step that can impact all subsequent analyses, towards the development of novel analytical strategies. To aid researchers to support the evolution of measurement science technology, this tutorial review evaluates and discuss the most commonly protocols used to characterize the contents of EVs, including their advantages and disadvantages in terms of experimental procedures, time and equipment. The purpose of this tutorial review is to offer practical guide to researchers which are intended to develop novel analytical approaches. Some of the most significant applications are considered, highlighting their main characteristics divided per mechanism of action. Finally, comprehensive tables which provide an overview at a glance are provided to readers.

Drug resistance in breast cancer is based on the mechanism of exocrine non-coding RNA

Breast cancer (BC) ranks first among female malignant tumors and involves hormonal changes and genetic as well as environmental risk factors. In recent years, with the improvement of medical treatment, a variety of therapeutic approaches for breast cancer have emerged and have strengthened to accommodate molecular diversity. However, the primary way to improve the effective treatment of breast cancer patients is to overcome treatment resistance. Recent studies have provided insights into the mechanisms of resistance to exosome effects in BC. Exosomes are membrane-bound vesicles secreted by both healthy and malignant cells that facilitate intercellular communication. Specifically, exosomes released by tumor cells transport their contents to recipient cells, altering their properties and promoting oncogenic components, ultimately resulting in drug resistance. As important coordinators, non-coding RNAs (ncRNAs) are involved in this process and are aberrantly expressed in various human cancers. Exosome-derived ncRNAs, including microRNAs (miRNAs), long-noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), have emerged as crucial components in understanding drug resistance in breast cancer. This review provides insights into the mechanism of exosome-derived ncRNAs in breast cancer drug resistance, thereby suggesting new strategies for the treatment of BC.

Fisetin suppresses chondrocyte senescence and attenuates osteoarthritis progression by targeting sirtuin 6

Osteoarthritis (OA) is the most common type of arthritis and is an age-related joint disease that is particularly prevalent in subjects over 65 years old. The chronic rise of senescent cells has a close correlation with age-related diseases such as OA, and the senescence-associated secretory phenotype (SASP) is implicated in OA cartilage degeneration pathogenesis. Sirtuin 6 (SIRT6) is likely to be a key senescence-related regulator. Fisetin (FST) is a natural flavonol of the flavonoid family that is recommended as a senolytic drug to extend health and lifespan. However, the potential chondroprotective effects of FST on OA rats are largely unclarified. The aim of this study is to investigate the ameliorative effects of FST on OA joint cartilage and the relationship with SIRT6 and the detailed mechanisms from anti-inflammatory and anti-senescent perspectives. Rats were subjected to destabilization of the medial meniscus (DMM) surgery as a means of inducing the experimental OA model in vivo. Chondrocytes treated with IL-1β were utilized for mimicking the OA cell model in vitro. Intra-articular injection of FST, OSS_128,167 (OSS, SIRT6 inhibitor), and MDL800 (MDL, SIRT6 agonist) in vivo or administering them in IL-1β-induced rat chondrocytes in vitro were performed in order to determine the effects FST has on OA and the link with SIRT6. This study found SIRT6 level to be negatively correlated with OA severity. SIRT6 downregulation was validated in the joint cartilages of DMM rats and IL-1β-treated chondrocytes. It was also notably demonstrated that FST can activate SIRT6. Both the administration of FST and activation of SIRT6 using MDL were found to rescue cartilage erosion, decrease extracellular matrix (ECM) degradation, prevent cartilage from apoptosis, and improve detrimental senescence-related phenotype. The alleviative effects of FST against inflammation, ECM degradation, apoptosis, and senescence in IL-1β-stimulated chondrocytes were also confirmed. SIRT6 loss occurs in articular cartilage in OA pathogenesis, which is linked to aging. FST attenuates injury-induced aging-related phenotype changes in chondrocytes through the targeting of SIRT6.

Alternative splicing and related RNA binding proteins in human health and disease

Alternative splicing (AS) serves as a pivotal mechanism in transcriptional regulation, engendering transcript diversity, and modifications in protein structure and functionality. Across varying tissues, developmental stages, or under specific conditions, AS gives rise to distinct splice isoforms. This implies that these isoforms possess unique temporal and spatial roles, thereby associating AS with standard biological activities and diseases. Among these, AS-related RNA-binding proteins (RBPs) play an instrumental role in regulating alternative splicing events. Under physiological conditions, the diversity of proteins mediated by AS influences the structure, function, interaction, and localization of proteins, thereby participating in the differentiation and development of an array of tissues and organs. Under pathological conditions, alterations in AS are linked with various diseases, particularly cancer. These changes can lead to modifications in gene splicing patterns, culminating in changes or loss of protein functionality. For instance, in cancer, abnormalities in AS and RBPs may result in aberrant expression of cancer-associated genes, thereby promoting the onset and progression of tumors. AS and RBPs are also associated with numerous neurodegenerative diseases and autoimmune diseases. Consequently, the study of AS across different tissues holds significant value. This review provides a detailed account of the recent advancements in the study of alternative splicing and AS-related RNA-binding proteins in tissue development and diseases, which aids in deepening the understanding of gene expression complexity and offers new insights and methodologies for precision medicine.

Exosomal miR-361-3p promotes the viability of breast cancer cells by targeting ETV7 and BATF2 to upregulate the PAI-1/ERK pathway

BACKGROUND

Malignant progression is the major cause of poor prognosis in breast cancer (BC) patients. Plasma exosomal miRNAs have been reported to be involved in tumor progression, but their roles in BC remain unclear.

METHODS

We performed plasma exosomal miRNA sequencing on 45 individuals, including healthy controls and nonmetastatic and metastatic BC patients. We examined the correlation between miRNA expression in tumor tissues and plasma exosomes in BC patients by qRT‒PCR. The effects of exosomal miR-361-3p on BC cells were determined by CellTiter-Glo, migration and wound healing assays. The target genes of miR-361-3p and downstream pathways were explored by dual-luciferase reporter assay, RNA knockdown, rescue experiments, and western blotting. We utilized murine xenograft model to further assess the impact of plasma exosomal miR-361-3p on the malignant progression of BC.

RESULTS

We found that the expression level of plasma exosomal miR-361-3p gradually increased with malignant progression in BC patients, and the expression of miR-361-3p in plasma exosomes and BC tissues was positively correlated. Consistently, exosomal miR-361-3p enhanced the migration and proliferation of two BC cell lines, MDA-MB-231 and SK-BR-3. Furthermore, our data showed that miR-361-3p inhibited two novel target genes, ETV7 and BATF2, to activate the PAI-1/ERK pathway, leading to increased BC cell viability. Finally, the consistency of the in vivo experimental results supported that elevated plasma exosomal miR-361-3p promote the malignant progression of BC.

CONCLUSIONS

We found for the first time that plasma exosomal miR-361-3p was associated with malignant progression in BC patients. Mechanistically, exosomal miR-361-3p can enhance the migration and proliferation of BC cells by targeting the ETV7 and BATF2/PAI-1/ERK pathways. Our data suggest that plasma exosomal miR-361-3p has the potential to serve as a biomarker for predicting malignant progression in BC patients.

Encapsulation and assessment of therapeutic cargo in engineered exosomes: a systematic review

Exosomes are nanoscale extracellular vesicles secreted by cells and enclosed by a lipid bilayer membrane containing various biologically active cargoes such as proteins, lipids, and nucleic acids. Engineered exosomes generated through genetic modification of parent cells show promise as drug delivery vehicles, and they have been demonstrated to have great therapeutic potential for treating cancer, cardiovascular, neurological, and immune diseases, but systematic knowledge is lacking regarding optimization of drug loading and assessment of delivery efficacy. This review summarizes current approaches for engineering exosomes and evaluating their drug delivery effects, and current techniques for assessing exosome drug loading and release kinetics, cell targeting, biodistribution, pharmacokinetics, and therapeutic outcomes are critically examined. Additionally, this review synthesizes the latest applications of exosome engineering and drug delivery in clinical translation. The knowledge compiled in this review provides a framework for the rational design and rigorous assessment of exosomes as therapeutics. Continued advancement of robust characterization methods and reporting standards will accelerate the development of exosome engineering technologies and pave the way for clinical studies.

The Emerging Roles of Exosomal miRNAs in Breast Cancer Progression and Potential Clinical Applications

Breast cancer remains the leading malignancy in terms of morbidity and mortality today. The tumor microenvironment of breast cancer includes multiple cell types, secreted proteins, and signaling components such as exosomes. Among these, exosomes have a lipid bilayer structure. Exosomes can reflect the biological traits of the parent cell and carry a variety of biologically active components, including proteins, lipids, small molecules, and non-coding RNAs, which include miRNA, lncRNA, and circRNA. MiRNAs are a group of non-coding RNAs of approximately 20-23 nucleotides in length encoded by the genome, triggering silencing and functional repression of target genes. MiRNAs have been shown to play a significant role in the development of cancer owing to their role in the prognosis, pathogenesis, diagnosis, and treatment of cancer. MiRNAs in exosomes can serve as effective mediators of information transfer from parental cells to recipient cells and trigger changes in biological traits such as proliferation, invasion, migration, and drug resistance. These changes can profoundly alter the progression of breast cancer. Therefore, here, we systematically summarize the association of exosomal miRNAs on breast cancer progression, diagnosis, and treatment in the hope of providing novel strategies and directions for subsequent breast cancer treatment.

Exosomal transfer leads to chemoresistance through oxidative phosphorylation-mediated stemness phenotype in colorectal cancer

Background: Recently years have seen the increasing evidence identifying that OXPHOS is involved in different processes of tumor progression and metastasis and has been proposed to be a potential therapeutical target for cancer treatment. However, the exploration in oxidative phosphorylation-mediated chemoresistance is still scarce. In our study, we identify exosomal transfer leads to chemoresistance by reprogramming metabolic phenotype in recipient cells. Methods: RNA sequencing analysis was used to screen altered targets mediating exosome transfer-induced chemoresistance. Seahorse assay allowed us to measure mitochondrial respiration. Stemness was measured by spheroids formation assay. Serum exosomes were isolated for circ_0001610 quantification. Results: The induced oxidative phosphorylation leads to more stem-like properties, which is dependent on the transfer of exosomal circ_0001610. Exosome transfer results in the removal of miR-30e-5p-mediated suppression of PGC-1a, a master of mitochondrial biogenesis and function. Consequently, increased PGC-1a reshapes cellular metabolism towards oxidative phosphorylation, leading to chemoresistance. Inhibition of OXPHOS or exosomal si-circ_0001610 increases the sensitivity of chemotherapy by decreasing cell stemness in vitro and in vivo. Conclusion: Our data suggests that exosomal circ_0001610-induced OXPHOS plays an important role in chemoresistance and supports a therapeutical potential of circ_0001610 inhibitors in the treatment of oxaliplatin-resistant colorectal cancer by manipulating cell stemness.

Regulatory miRNAs in cancer cell recovery from therapy exposure and its implications as a novel therapeutic strategy for preventing disease recurrence

The desired outcome of cancer therapies is the eradication of disease. This can be achieved when therapy exposure leads to therapy-induced cancer cell death as the dominant outcome. Theoretically, a permanent therapy-induced growth arrest could also contribute to a complete response, which has the potential to lead to remission. However, preclinical models have shown that therapy-induced growth arrest is not always durable, as recovering cancer cell populations can contribute to the recurrence of cancer. Significant research efforts have been expended to develop strategies focusing on the prevention of recurrence. Recovery of cells from therapy exposure can occur as a result of several cell stress adaptations. These include cytoprotective autophagy, cellular quiescence, a reversable form of senescence, and the suppression of apoptosis and necroptosis. It is well documented that microRNAs regulate the response of cancer cells to anti-cancer therapies, making targeting microRNAs therapeutically a viable strategy to sensitization and the prevention of recovery. We propose that the use of microRNA-targeting therapies in prolonged sequence, that is, a significant period after initial therapy exposure, could reduce toxicity from the standard combination strategy, and could exploit new epigenetic states essential for cancer cells to recover from therapy exposure. In a step toward supporting this strategy, we survey the available scientific literature to identify microRNAs which could be targeted in sequence to eliminate residual cancer cell populations that were arrested as a result of therapy exposure. It is our hope that by successfully identifying microRNAs which could be targeted in sequence we can prevent disease recurrence.

Functions of exosomal non-coding RNAs to the infection with Mycobacterium tuberculosis

Tuberculosis (TB) is a major infectious disease induced by Mycobacterium tuberculosis (M. tb) which causes the world's dominant fatal bacterial contagious disease. Increasing studies have indicated that exosomes may be a novel option for the diagnosis and treatment of TB. Exosomes are nanovesicles (30-150 nm) containing lipids, proteins and non-coding RNAs (ncRNAs) released from various cells, and can transfer their cargos and communicate between cells. Furthermore, exosomal ncRNAs exhibit diagnosis potential in bacterial infections, including TB. Additionally, differential exosomal ncRNAs regulate the physiological and pathological functions of M. tb-infected cells and act as diagnostic markers for TB. This current review explored the potential biological roles and the diagnostic application prospects of exosomal ncRNAs, and included recent information on their pathogenic and therapeutic functions in TB.