Despite their small size, the membrane-bound particles named extracellular vesicles (EVs) seem to play an enormous role in the pathogenesis of acute leukemia. From oncogenic hematopoietic stem cells (HSCs) to become leukemic cells to alter the architecture of bone marrow (BM) microenvironment, EVs are critical components of leukemia development. As a carrier of essential molecules, especially a group of small non-coding RNAs known as miRNA, recently, EVs have attracted tremendous attention as a prognostic factor. Given the importance of miRNAs in the early stages of leukemogenesis and also their critical parts in the development of drug-resistant phenotype, it seems that the importance of EVs in the development of leukemia is more than what is expected. To be familiar with the clinical value of leukemia-derived EVs, this review aimed to briefly shed light on the biology of EVs and to discuss the role of EV-derived miRNAs in the development of acute myeloid leukemia and acute lymphoblastic leukemia. By elaborating the advances and challenges concerning the isolation of EVs, we discuss whether EVs could have a prognostic value in the clinical setting for leukemia.
Abstract Acute myeloid leukemia represents a group of malignant blood disorders that originate from clonal over-proliferation and the differentiation failure of hematopoietic precursors, resulting in the accumulation of blasts in the bone marrow. Mesenchymal stromal cells (MSCs) have been shown to exert diverse effects on tumor cells through direct and indirect interaction. Exosomes, as one of the means of indirect intercellular communication, are released from different types of cells, including MSCs, and their various contents, such as lncRNAs, enable them to exert significant impacts on target cells. Our study aims to investigate the effects of BM-MSC exosomes on the cellular and molecular characterization of HL-60 AML cells, particularly detecting the alterations in the expression of lncRNAs involved in AML leukemogenesis, cell growth, drug resistance, and poor prognosis. BM-MSCs were cultured with serum-free culture media to isolate exosomes from their supernatants. The validation of exosomes was performed in three stages: morphological analysis using TEM, size evaluation using DLS, and CD marker identification using flow cytometry. Subsequently, the HL-60 AML cells were treated with isolated BM-MSC exosomes to determine the impact of their contents on leukemic cells. Cell metabolic activity was evaluated by the MTT assay, while cell cycle progression, apoptosis, ROS levels, and proliferation were assessed by flow cytometry. Furthermore, RT-qPCR was conducted to determine the expression levels of lncRNAs and apoptosis-, ROS-, and cell cycle-related genes. MTT assay and flow cytometry analysis revealed that BM-MSC exosomes considerably suppressed cell metabolic activity, proliferation, and cell cycle progression. Also, these exosomes could effectively increase apoptosis and ROS levels in HL-60 cells. The expression levels of p53, p21, BAX, and FOXO4 were increased, while the BCL2 and c-Myc levels decreased. MALAT1, HOTAIR, and H19 expression levels were also significantly decreased in treated HL-60 cells compared to their untreated counterparts. BM-MSC exosomes suppress cell cycle progression, proliferation, and metabolic activity while simultaneously elevating the ROS index and apoptosis ratio in HL-60 cells, likely by reducing the expression levels of MALAT1, HOTAIR, and H19. These findings suggest that BM-MSC exosomes might serve as potential supportive therapies for leukemia.
Exosomes are small endosomal derived membrane extracellular vesicles that contain cell-specific cargos such as lipid, protein, DNA, RNA, miRNA, long non-coding RNA, and some other cell components that are released into surrounding body fluids upon the fusion of multivesicular bodies (MVB) and the plasma membrane. Exosomes are a one-of-a-kind cell-to-cell communication mechanism that might pave the way for target therapy. The use of exosomes as a therapeutic potential in a variety of cancers has been and is still being investigated. One of the most important of these has been the use of exosomes in brain tumors therapy. Exosome contents play a crucial role in brain tumor progression by providing a favorable niche for tumor cell proliferation. Also, exosomes that are secreted from tumor cells, lead to the protection of tumor cells and their proliferation in the tumor environment by reducing the inflammatory response and suppression of the immune system. Although some treatment protocols such as surgery, chemotherapy, and radiotherapy are common in brain tumors, they do not result in complete remission in the treatment of some malignant and metastatic brain tumors. Identifying, targeting, and blocking exosomes involved in the progression of brain tumors could be a promising way to reduce brain tumor progression. On the other way, brain tumor therapy with effective therapeutic components such as siRNAs, mRNAs, proteins, could be developed. Finally, our research suggested that exosomes of nanoscale sizes might be a useful tool for crossing the blood-brain barrier and delivering effective content. However, further research is needed to fully comprehend the potential involvement of the exosome in brain tumor therapy protocols.
Abstract The use of all‐trans retinoic acid and arsenic trioxide resulted in favourable therapeutic responses in standard‐risk acute promyelocytic leukaemia (APL) patients. However, resistance to these agents has made treating the high‐risk subgroup more problematic, and possible side effects limit their clinical dosages. Numerous studies have proven the cytotoxic properties of Gaillardin, one of the Inula oculus‐christi ‐derived sesquiterpene lactones. Due to the adverse effects of arsenic trioxide on the high‐risk subgroup of APL patients, we aimed to assess the cytotoxic effect of Gaillardin on HL‐60 cells as a single or combined‐form approach. The results of the trypan blue and MTT assays outlined the potent cytotoxic properties of Gaillardin. The flow cytometric analysis and the mRNA expression levels revealed that Gaillardin attenuated the proliferative capacity of HL‐60 cells through cell cycle arrest and induced apoptosis via reactive oxygen species generation. Moreover, the results of synergistic experiments indicated that this sesquiterpene lactone sensitizes HL‐60 cells to the cytotoxic effects of arsenic trioxide. Taken together, the findings of the present investigation highlighted the antileukemic characteristics of Gaillardin by inducing G1 cell cycle arrest and triggering apoptosis. Gaillardin acts as an antileukemic metabolite against HL‐60 cells and this study provides new insight into treating APL patients, especially in the high‐risk subgroup.
Until recently, a conventional chemotherapy regimen for Acute lymphoblastic leukemia (ALL) is considered an efficient therapeutic method in children. However, suboptimal long-term survival rates in adults, disease relapse, and drug-induced toxicities require novel therapeutic agents for ALL treatments. Today, natural products with pharmacological benefits play a significant role in treating different cancers. Among the most valued natural products, honey bees' royal jelly (RJ) is one of the most appreciated which has revealed anti-tumor activity against different human cancers. This study aimed to evaluate anti-leukemic properties and the molecular mechanisms of RJ cytotoxicity on ALL-derived Nalm-6 cells.
Background Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous neoplasm and is characterized as the most common subtype of non-Hodgkin lymphoma (NHL). Despite 60–70% of all patients being cured with R-CHOP therapeutic regimen (Cyclophosphamide, doxorubicin, vincristine, and prednisone, combined with rituximab), remaining patients display aggressive disease. Therefore, there is an urgent need to develop novel diagnostic, prognostic, and predictive biomarkers. Recently, exosomal miRNAs have been approved as novel biomarkers in DLBCL due to their potential involvement in lymphomagenesis. Material and Methods We conducted an investigation on the potential role of exosomal miRNAs as diagnostic, prognostic, and predictive biomarkers in DLBCL in the PubMed, Scopus, and Web of Science search engines. We searched by using a combination of keywords, such as diffuse large B-cell lymphoma, DLBCL, miRNA, microRNA, miR, exosome, exosomes, exosomal, extracellular vesicles, EVs, and secretome. Then, search results were narrowed based on specific inclusion and exclusion criteria. Results Twelve articles were eligible for our systematic reviews. Among them, nine discussed diagnostic biomarkers, three considered prognostic significance, four evaluated therapeutic efficacy, two studies were conducted in vitro , and three assessed molecular pathways associated with these exosomal miRNAs in DLBCL. Discussion According to our systematic review, exosomal miRNAs are not only useful for diagnosis and prognosis in DLBCL but are also promising therapeutic tools and predictors of response to therapy. Although promising results so far, more research is required to develop innovative biomarkers.