miR-224-5p Carried by Human Umbilical Cord Mesenchymal Stem Cells-Derived Exosomes Regulates Autophagy in Breast Cancer Cells via HOXA5

The role of mesenchymal stem cells in cancer and prospects for their use in cancer therapeutics

Mesenchymal stem cells (MSCs) are recruited by malignant tumor cells to the tumor microenvironment (TME) and play a crucial role in the initiation and progression of malignant tumors. This role encompasses immune evasion, promotion of angiogenesis, stimulation of cancer cell proliferation, correlation with cancer stem cells, multilineage differentiation within the TME, and development of treatment resistance. Simultaneously, extensive research is exploring the homing effect of MSCs and MSC-derived extracellular vesicles (MSCs-EVs) in tumors, aiming to design them as carriers for antitumor substances. These substances are targeted to deliver antitumor drugs to enhance drug efficacy while reducing drug toxicity. This paper provides a review of the supportive role of MSCs in tumor progression and the associated molecular mechanisms. Additionally, we summarize the latest therapeutic strategies involving engineered MSCs and MSCs-EVs in cancer treatment, including their utilization as carriers for gene therapeutic agents, chemotherapeutics, and oncolytic viruses. We also discuss the distribution and clearance of MSCs and MSCs-EVs upon entry into the body to elucidate the potential of targeted therapies based on MSCs and MSCs-EVs in cancer treatment, along with the challenges they face.

Different origin-derived exosomes and their clinical advantages in cancer therapy

Exosomes, as a class of small extracellular vesicles closely related to the biological behavior of various types of tumors, are currently attracting research attention in cancer diagnosis and treatment. Regarding cancer diagnosis, the stability of their membrane structure and their wide distribution in body fluids render exosomes promising biomarkers. It is expected that exosome-based liquid biopsy will become an important tool for tumor diagnosis in the future. For cancer treatment, exosomes, as the "golden communicators" between cells, can be designed to deliver different drugs, aiming to achieve low-toxicity and low-immunogenicity targeted delivery. Signaling pathways related to exosome contents can also be used for safer and more effective immunotherapy against tumors. Exosomes are derived from a wide range of sources, and exhibit different biological characteristics as well as clinical application advantages in different cancer therapies. In this review, we analyzed the main sources of exosomes that have great potential and broad prospects in cancer diagnosis and therapy. Moreover, we compared their therapeutic advantages, providing new ideas for the clinical application of exosomes.

Novel exosomal circEGFR facilitates triple negative breast cancer autophagy via promoting TFEB nuclear trafficking and modulating miR-224-5p/ATG13/ULK1 feedback loop

Triple-negative breast cancer (TNBC) cells are in a more hypoxic and starved state than non-TNBC cells, which makes TNBC cells always maintain high autophagy levels. Emerging evidence has demonstrated that circular RNAs (circRNAs) are involved in the progress of tumorigenesis. However, the regulation and functions of autophagy-induced circRNAs in TNBC remain unclear. In our study, autophagy-responsive circRNA candidates in TNBC cells under amino acid starved were identified by RNA sequencing. The results showed that circEGFR expression was significantly upregulated in autophagic cells. Knockdown of circEGFR inhibited autophagy in TNBC cells, and circEGFR derived from exosomes induced autophagy in recipient cells in the tumor microenvironment. In vitro and in vivo functional assays identified circEGFR as an oncogenic circRNA in TNBC. Clinically, circEGFR was significantly upregulated in TNBC and was positively associated with lymph node metastasis. CircEGFR in plasma-derived exosomes was upregulated in breast cancer patients compared with healthy people. Mechanistically, circEGFR facilitated the translocation of Annexin A2 (ANXA2) toward the plasma membrane in TNBC cells, which led to the release of Transcription Factor EB (a transcription factor of autophagy-related proteins, TFEB) from ANXA2-TFEB complex, causing nuclear translocation of TFEB, thereby promoting autophagy in TNBC cells. Meanwhile, circEGFR acted as ceRNA by directly binding to miR-224-5p and inhibited the expression of miR-224-5p, which weakened the suppressive role of miR-224-5p/ATG13/ULK1 axis on autophagy. Overall, our study demonstrates the key role of circEGFR in autophagy, malignant progression, and metastasis of TNBC. These indicate circEGFR is a potential diagnosis biomarker and therapeutic target for TNBC.

Extracellular Vesicles-A Source of RNA Biomarkers for the Detection of Breast Cancer in Liquid Biopsies

Over the past decade, extracellular vesicles (EVs) have emerged as a promising source of cancer-derived RNAs for liquid biopsies. However, blood contains a pool of heterogeneous EVs released by a variety of cell types, making the identification of cancer RNA biomarkers challenging. Here, we performed deep sequencing of plasma EV RNA cargo in 32 patients with locally advanced breast cancer (BC) at diagnosis and 7 days after breast surgery and in 30 cancer-free healthy controls (HCs). To identify BC-derived RNA biomarkers, we searched for RNAs that had higher levels in BC EVs at the time of diagnosis compared with HCs and decreased after surgery. Data analysis showed that the fractions of miRNAs, snRNAs, snoRNAs, and tRFs were increased, but the fraction of lncRNAs was decreased in BC EVs as compared to HCs. BC-derived biomarker candidates were identified across various RNA biotypes. Considered individually, they had very high specificity but moderate sensitivity for the detection of BC, whereas a biomarker model composed of eight RNAs: SNORD3H, SNORD1C, SNORA74D, miR-224-5p, piR-32949, lnc-IFT-122-2, lnc-C9orf50-4, and lnc-FAM122C-3 was able to distinguish BC from HC EVs with an AUC of 0.902 (95% CI = 0.872-0.931, p = 3.4 × 10-9) in leave-one-out cross-validation. Furthermore, a number of RNA biomarkers were correlated with the ER and HER2 expression and additional biomarker models were created to predict hormone receptor and HER2 status. Overall, this study demonstrated that the RNA composition of plasma EVs is altered in BC patients and that they contain cancer-derived RNA biomarkers that can be used for BC detection and monitoring using liquid biopsies.

miRNA-Guided Regulation of Mesenchymal Stem Cells Derived from the Umbilical Cord: Paving the Way for Stem-Cell Based Regeneration and Therapy

The human body is an abundant source of multipotent cells primed with unique properties that can be exploited in a multitude of applications and interventions. Mesenchymal stem cells (MSCs) represent a heterogenous population of undifferentiated cells programmed to self-renew and, depending on their origin, differentiate into distinct lineages. Alongside their proven ability to transmigrate toward inflammation sites, the secretion of various factors that participate in tissue regeneration and their immunoregulatory function render MSCs attractive candidates for use in the cytotherapy of a wide spectrum of diseases and conditions, as well as in different aspects of regenerative medicine. In particular, MSCs that can be found in fetal, perinatal, or neonatal tissues possess additional capabilities, including predominant proliferation potential, increased responsiveness to environmental stimuli, and hypoimmunogenicity. Since microRNA (miRNA)-guided gene regulation governs multiple cellular functions, miRNAs are increasingly being studied in the context of driving the differentiation process of MSCs. In the present review, we explore the mechanisms of miRNA-directed differentiation of MSCs, with a special focus on umbilical cord-derived mesenchymal stem cells (UCMSCs), and we identify the most relevant miRNAs and miRNA sets and signatures. Overall, we discuss the potent exploitations of miRNA-driven multi-lineage differentiation and regulation of UCMSCs in regenerative and therapeutic protocols against a range of diseases and/or injuries that will achieve a meaningful clinical impact through maximizing treatment success rates, while lacking severe adverse events.

Proteotoxic stress-induced autophagy is regulated by the NRF2 pathway via extracellular vesicles

Protein homeostasis involves a number of overlapping mechanisms, including the autophagy program, that can lead to the resolution of protein damage. We aimed in this study to examine mechanisms of autophagy in the proteotoxic stress response. We found that such stress results in a rapid elevation in the rate of autophagy in mammalian cells. Induction of this process occurred coincidentally with the increased release of extracellular vesicles (EVs) into the extracellular microenvironment. We next found that purified EVs that had been released from stressed cells were capable of directly increasing autophagic flux in recipient cells. The EVs contained a range of cargo proteins, including HSP70, BAG3, and activated transcription factor phospho-NRF2 (pNRF2). NRF2 regulates the activation of both the oxidative stress response and autophagy genes. Both heat shock and exposure of cells to proteotoxic stress-induced EVs increased the intracellular levels of pNRF2 in cells. Heat shock-induced proteotoxicity also led to increases in the levels of proteins in the oxidative stress response, including HO-1 and NQO1, as well as the key autophagy proteins LC3, ATG5, and ATG7, known to be regulated by NRF2. Increases in these autophagy proteins were dependent on the expression of NRF2 and were ablated by NRF2 knockdown.

Shining the light on mesenchymal stem cell-derived exosomes in breast cancer

In women, breast cancer (BC) is the second most frequently diagnosed cancer and the leading cause of cancer death. Mesenchymal stem cells (MSCs) are a subgroup of heterogeneous non-hematopoietic fibroblast-like cells that have the ability to differentiate into multiple cell types. Recent studies stated that MSCs can migrate into the tumor sites and exert various effect on tumor growth and development. Multiple researches have demonstrated that MSCs can favor tumor growth, while other groups have indicated that MSCs inhibit tumor development. Emerging evidences showed exosomes (Exo) as a new mechanism of cell communication which are essential for the crosstalk between MSCs and BC cells. MSC-derived Exo (MSCs-Exo) could mimic the numerous effects on the proliferation, metastasis, and drug response through carrying a wide scale of molecules, such as proteins, lipids, messenger RNAs, and microRNAs to BC cells. Consequently, in the present literature, we summarized the biogenesis and cargo of Exo and reviewed the role of MSCs-Exo in development of BC.

Exosomal miR-767 from senescent endothelial-derived accelerating skin fibroblasts aging via inhibiting TAB1

Skin aging is a complicated physiological process, and microRNA-mediated regulation has been shown to contribute to this process. Exosomes mediate intercellular communication through miRNAs, mRNAs and proteins, and participate in many physiological and pathological processes. Vascular endothelial cell-derived exosomes have been confirmed to be involved in the development of many diseases, however, their effects on skin aging have not been reported. In this study, senescent endothelial cells could regulate skin fibroblast functions and promote cell senescence through exosomal pathway. miR-767 was highly expressed in senescent vascular endothelial cells and their exosomes, and miR-767 is also upregulated in skin fibroblasts after treatment with exosomes derived from senescent vascular endothelial cells. In addition, transfection with miR-767 mimic promoted senescence of skin fibroblasts, while transfection with miR-767 inhibitor reversed the effect of D-galactose. Double luciferase analysis confirmed that TAB1 was a direct target gene of miR-767. Furthermore, miR-767 expression was increased and TAB1 expression was decreased in D-galactose induced aging mice. In mice that overexpressed miR-767, HE staining showed thinning of dermis and senescence appearance. In conclusion, senescent vascular endothelial cell-derived exosome mediated miR-767 regulates skin fibroblasts through the exosome pathway. Our study reveals the role of vascular endothelial cell-derived exosomes in aging in the skin microenvironment and contributes to the discovery of new targets for delaying senescence.

Application of Perinatal Derivatives on Oncological Preclinical Models: A Review of Animal Studies

The increasing cancer incidence has certified oncological management as one of the most critical challenges for the coming decades. New anticancer strategies are still needed, despite the significant advances brought to the forefront in the last decades. The most recent, promising therapeutic approaches have benefitted from the application of human perinatal derivatives (PnD), biological mediators with proven benefits in several fields beyond oncology. To elucidate preclinical results and clinic outcomes achieved in the oncological field, we present a narrative review of the studies resorting to animal models to assess specific outcomes of PnD products. Recent preclinical evidence points to promising anticancer effects offered by PnD mediators isolated from the placenta, amniotic membrane, amniotic fluid, and umbilical cord. Described effects include tumorigenesis prevention, uncontrolled growth or regrowth inhibition, tumor homing ability, and adequate cell-based delivery capacity. Furthermore, PnD treatments have been described as supportive of chemotherapy and radiological therapies, particularly when resistance has been reported. However, opposite effects of PnD products have also been observed, offering support and trophic effect to malignant cells. Such paradoxical and dichotomous roles need to be intensively investigated. Current hypotheses identify as explanatory some critical factors, such as the type of the PnD biological products used or the manufacturing procedure to prepare the tissue/cellular treatment, the experimental design (including human-relevant animal models), and intrinsic pathophysiological characteristics. The effective and safe translation of PnD treatments to clinical practice relies on the collaborative efforts of all researchers working with human-relevant oncological preclinical models. However, it requires proper guidelines and consensus compiled by experts and health workers who accurately describe the methodology of tissue collection, PnD isolation, manufacturing, preservation, and delivery to the final user.

MicroRNA-375 is a therapeutic target for castration-resistant prostate cancer through the PTPN4/STAT3 axis

The functional role of microRNA-375 (miR-375) in the development of prostate cancer (PCa) remains controversial. Previously, we found that plasma exosomal miR-375 is significantly elevated in castration-resistant PCa (CRPC) patients compared with castration-sensitive PCa patients. Here, we aimed to determine how miR-375 modulates CRPC progression and thereafter to evaluate the therapeutic potential of human umbilical cord mesenchymal stem cell (hucMSC)-derived exosomes loaded with miR-375 antisense oligonucleotides (e-375i). We used miRNA in situ hybridization technique to evaluate miR-375 expression in PCa tissues, gain- and loss-of-function experiments to determine miR-375 function, and bioinformatic methods, dual-luciferase reporter assay, qPCR, IHC and western blotting to determine and validate the target as well as the effects of miR-375 at the molecular level. Then, e-375i complexes were assessed for their antagonizing effects against miR-375. We found that the expression of miR-375 was elevated in PCa tissues and cancer exosomes, correlating with the Gleason score. Forced expression of miR-375 enhanced the expression of EMT markers and AR but suppressed apoptosis markers, leading to enhanced proliferation, migration, invasion, and enzalutamide resistance and decreased apoptosis of PCa cells. These effects could be reversed by miR-375 silencing. Mechanistically, miR-375 directly interfered with the expression of phosphatase nonreceptor type 4 (PTPN4), which in turn stabilized phosphorylated STAT3. Application of e-375i could inhibit miR-375, upregulate PTPN4 and downregulate p-STAT3, eventually repressing the growth of PCa. Collectively, we identified a novel miR-375 target, PTPN4, that functions upstream of STAT3, and targeting miR-375 may be an alternative therapeutic for PCa, especially for CRPC with high AR levels.

Emerging role of exosomes in cancer progression and tumor microenvironment remodeling

Cancer is one of the leading causes of death worldwide, and the factors responsible for its progression need to be elucidated. Exosomes are structures with an average size of 100 nm that can transport proteins, lipids, and nucleic acids. This review focuses on the role of exosomes in cancer progression and therapy. We discuss how exosomes are able to modulate components of the tumor microenvironment and influence proliferation and migration rates of cancer cells. We also highlight that, depending on their cargo, exosomes can suppress or promote tumor cell progression and can enhance or reduce cancer cell response to radio- and chemo-therapies. In addition, we describe how exosomes can trigger chronic inflammation and lead to immune evasion and tumor progression by focusing on their ability to transfer non-coding RNAs between cells and modulate other molecular signaling pathways such as PTEN and PI3K/Akt in cancer. Subsequently, we discuss the use of exosomes as carriers of anti-tumor agents and genetic tools to control cancer progression. We then discuss the role of tumor-derived exosomes in carcinogenesis. Finally, we devote a section to the study of exosomes as diagnostic and prognostic tools in clinical courses that is important for the treatment of cancer patients. This review provides a comprehensive understanding of the role of exosomes in cancer therapy, focusing on their therapeutic value in cancer progression and remodeling of the tumor microenvironment.

Melatonin Induces Autophagy in Amyotrophic Lateral Sclerosis Mice via Upregulation of SIRT1

Amyotrophic lateral sclerosis (ALS) is the neurodegenerative disease that leads to the motor dysfunction damaged by both upper and lower motor neurons. The etiology and pathogenesis of ALS hasn't completely been understood yet up to now, the current study suggests that autophagy plays an important role in the development of ALS. Meanwhile, melatonin is found to inhibit the progression of ALS. To this end, this study aimed to investigate the potential relation between melatonin and autophagy in ALS. The in vivo model of ALS was established to investigate the effects of melatonin in ALS. The mRNA expressions were performed to detect by RT-qPCR, and the protein levels were tested by western blot and immunofluorescence histochemistry staining. The inflammatory cytokine was applied to detect by ELISA. The results showed that melatonin dose-dependently reversed the ALS-induced survival time shortened, weight loss and rotating rod latency decrease. The expressions of both SIRT1 and Beclin-1 as well as the ratio of LC3II/LC3I were significantly upregulated in the ALS mice, while melatonin reversed the upregulation of both SIRT1 and Beclin-1 expression and LC3II/LC3I ratio in a dose-dependent manner. In contrast, melatonin dose-dependently significantly restored the ALS-induced downregulation of p62. Furthermore, SIRT1 silencing notably reduced the effect of melatonin on Beclin-1, LC3II/LC3I, and p62. Melatonin induced autophagy in the ALS mice via the upregulation of SIRT1. Thus, melatonin might act as a new agent for the treatment of ALS.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: Pleiotropic Impacts on Breast Cancer Occurrence, Development, and Therapy

Breast cancer (BC) is one of the most devastating cancers, with high morbidity and mortality, among the female population worldwide. In BC, mesenchymal stem cells (MSCs), as pluripotent stromal stem cells, play a significant role in TME formation and tumor progression. Recently, an increasing number of studies have demonstrated that extracellular vesicles (EVs) are essential for the crosstalk between MSCs and BC cells. MSC-derived EVs (MSC-EVs) can deliver a diversity of molecules, including lipids, proteins, and nucleic acids, etc., to target cells, and produce corresponding effects. Studies have demonstrated that MSC-EVs exert both inhibitory and promotive effects in different situations and different stages of BC. Meanwhile, MSC-EVs provide novel therapeutic options for BC, such as EVs as carriers for drug delivery. Therefore, in this review, we summarize the role of MSC-EVs in BC progression and application in clinical treatment, in the hope of providing a basis for further research.

E2F1-induced microRNA-224-5p expression is associated with hepatocellular carcinoma cell migration, invasion and epithelial-mesenchymal transition via MREG

MicroRNA (miR)-224-5p has been reported to be associated with multiple types of cancer. However, its biological role and underlying mechanism in hepatocellular carcinoma (HCC) has yet to be fully elucidated. The aim of the present study was to investigate whether miR-224-5p mRNA expression level was increased in hepatocellular carcinoma and whether it was associated with poor prognosis. Decreased mRNA expression level of miR-224-5p was shown to suppress liver cancer cell migration, invasion and epithelial-mesenchymal transition (EMT). Mechanistically, E2F1 was found to regulate miR-224-5p expression by binding to its promoter region. Melanoregulin (MREG) was identified as the direct target of miR-224-5p by searching the TargetScan, miRDB and StarBase databases. Overexpression of MREG could attenuate liver cancer cell migration, invasion and EMT. Rescue experiments further confirmed that MREG was associated with the regulation of miR-224-5p in liver cancer. In addition, the E2F1/miR-224-5p axis was shown to promote liver cancer cell migration, invasion and EMT by regulating MREG expression. These results suggested that E2F1-induced upregulation of miR-224-5p may serve an important role in MREG-induced liver cancer cell migration, invasion and EMT, and highlights the regulatory function of miR-224-5p in liver cancer. Therefore, the E2F1/miR-224-5p/MREG axis may provide a theoretical basis for the clinical treatment of hepatocellular carcinoma.