Encapsulation of daunorubicin into Saccharomyces cerevisiae-derived lysosome as drug delivery vehicles for acute myeloid leukemia (AML) treatment

Reassembled Vacuoles for Drug Delivery Carriers Using Yeast Vacuoles for Enhanced Antibacterial Activity

In this study, we aimed to develop an efficient drug delivery system by reassembling vacuoles isolated from Saccharomyces cerevisiae. Initially, we assessed the impact of vacuolar enzymes on the efficacy of the loaded antibiotic polymyxin B (PMB), by conducting antibacterial activity tests using Shigella flexneri and Salmonella enteritidis. The results showed that vacuolar enzymes inhibited the effectiveness of PMB, highlighting the limitations of using natural vacuoles as drug carriers. To overcome this, we proposed a new drug delivery system called reassembled vacuoles (ReV). ReV particles were created by removing vacuolar enzymes and reassembling the vacuolar membrane through extrusion. ReV demonstrated improved structural stability, a more uniform size, and enhanced PMB release compared to natural vacuoles. Encapsulation efficiency tests revealed high loading efficiency for both normal vacuoles (NorV) and ReV, with over 80% efficiency at concentrations up to 600 μg/mL. The antibacterial activity of PMB-loaded ReV showed comparable results to PMB alone, indicating the potential of ReV as a drug delivery system. In conclusion, reassembled vacuoles offer a promising approach for drug delivery, addressing the limitations of natural vacuoles and providing opportunities for targeted and efficient drug release.

Cellular organelles as drug carriers for disease treatment

Organelles not only constitute the basic structure of the cell but also are important in maintaining the normal physiological activities of the cell. With the development of biomimetic nanoscience, researchers have developed technologies to use organelles as drug carriers for disease treatment. Compared with traditional drug carriers, organelle drug carriers have the advantages of good biocompatibility, high drug loading efficiency, and modifiability, and the surface biomarkers of organelles can also participate in intracellular signal transduction to enhance intracellular and intercellular communication, and assist in enhancing the therapeutic effect of drugs. Among different types of organelles, extracellular vesicles, lipid droplets, lysosomes, and mitochondria have been used as drug carriers. This review briefly reviews the biogenesis, isolation methods, and drug-loading methods of four types of organelles, and systematically summarizes the research progress in using organelles as drug-delivery systems for disease treatment. Finally, the challenges faced by organelle-based drug delivery systems are discussed. Although the organelle-based drug delivery systems still face challenges before they can achieve clinical translation, they offer a new direction and vision for the development of next-generation drug carriers.

Inducing a Proinflammatory Response with Bioengineered Yeast Vacuoles with TLR2-Binding Peptides (VacT2BP) as a Drug Carrier for Daunorubicin Delivery

Immune adjuvants have roles in immune activation for cancer therapy, and adjuvants derived from microbes have been applied. In this study, we propose the use of bioengineered vacuoles, derived from recombinant yeast with acute myeloid leukemia (AML) specificity and having a TLR-2-binding peptide (VacT2BP) on their surface, to induce a proinflammatory response as a dual-function nanomaterial for daunorubicin (DNR) delivery. Our results demonstrate that nanosized, isolated VacT2BP induced HL-60 cell-specific DNR delivery and apoptosis. Furthermore, we observed the selective release of high-mobility group box 1 from apoptotic HL-60 cells by DNR@VacT2BP. We concluded that DNR@VacT2BP exhibited target selectivity, and the indiscriminate occurrence of damage-associated molecular patterns (DAMPs) was inhibited by the VacT2BP carrier. The therapeutic efficacy of DNR@VacT2BP was confirmed in AML xenograft mice, with about 82% tumor growth inhibition. Following drug delivery, apoptotic cells and DAMPs with residual VacT2BP (apopDNR@VacT2BP) upregulated the proinflammatory immune response of macrophages. In addition, apopDNR@VacT2BP enhanced phagocytosis activity. Macrophages stimulated by apopDNR@VacT2BP suppressed cancer proliferation by about 40%. In summary, our results suggest that dual-functional vacuoles with a target-specific peptide can be a potential strategy for selective drug delivery and construction of an immune environment to fight cancer, thereby improving prognosis.

Inhibition of Enveloped Virus Surrogate Phi6 Infection Using Yeast-Derived Vacuoles

The periodic emergence of infectious disease poses a serious threat to human life. Among the causative agents, including pathogenic bacteria and fungi, enveloped viruses have caused global pandemics. In the last 10 years, outbreaks of severe acute respiratory syndrome coronavirus 2 disease, severe acute respiratory syndrome, and Middle East respiratory syndrome have all been caused by enveloped viruses. Among several paths of secondary transmission, inhalation of aerosols containing saliva with sputum droplets from infected patients is the major path. To prevent these infectious diseases, mass use of antiviral agents is essential. The yeast-derived vacuole is a small organelle in which hydrolytic enzymes are concentrated. It is an intracellular organ with an excellent ability to process old organelles and bacteria and viruses that have invaded from the outside and can be present in sufficient quantity to be called a kind of enzyme bomb. We confirmed the inhibition of virus infection and structural collapse by vacuole treatment. Among several enzymes, proteases affected Phi6 infectivity. This study tried to isolate these vacuoles from yeast and use them as an antiviral agent for virus treatment, which is a recent issue. We confirmed that viral infectivity was inactivated, and structure collapsed through vacuole treatment. This paper is meaningful in that extracellularly isolated yeast-derived vacuoles are a first attempt to utilize vacuoles for viral treatment. IMPORTANCE The study assesses the vacuoles isolated from the yeast Saccharomyces cerevisiae as green antiviral agents to decrease the concerns about massive use of chemical antiviral agents and its side effects. To prevent the spreading of infectious diseases, personal or public use of antiviral agents is encouraged. The concern about the active compounds of these chemical antiviral agents has grown. Active compounds of antiviral agents have potential side effects on human health and the environment. Our proposed approach suggests effective and green antivirus material from a nonhazardous yeast strain. Also, large-scale production using a fermentation process can allow cost-effectiveness. The results showed sufficient reduced infectivity by vacuole treatment. The exposed vacuole can play the roles of both enzyme bomb to the virus and renewable nutrient source in the ecosystem.

Yeast-derived vacuoles as a novel carrier with enhanced hCMEC/D3 cell monolayer penetration

The blood-brain barrier (BBB) is a brain protection structure that restricts drug delivery from the blood to the central nervous system. Thus, we developed a novel drug carrier using yeast vacuoles to overcome this problem. The purpose of this study was to assess the drug transportability of yeast vacuoles using a human cerebral microvascular endothelial cell line (hCMEC/D3) cell monolayer. Here, we used daunorubicin (DNR) as a microtubule-targeting agent with the ability to disaggregate pre-formed fibrils and prevent Tau fibrillization. An in vitro model was developed by culturing hCMEC/D3 cells on Transwell inserts in EBM-2 endothelial basal medium until the cells formed a monolayer. Next, nano-sized yeast vacuoles were loaded with DNR, and the signals inside and outside the hMEC/D3 cell monolayer were detected using the GloMax^® Explorer fluorometer. DNR penetrated the cell monolayer and was regulated by endocytosis via receptor-mediated macropinocytosis on the surface of the cell. Confocal imaging showed a significant increase in intracellular DNR fluorescence when the cells were treated with the vacuole-encapsulated drug. These results indicate that the drug penetrated the hCMEC/D3 cell monolayer via encapsulation into the vacuoles. Overall, yeast-derived vacuoles are promising candidates as drug carriers to the brain.

Surface-modified vacuole-based daunorubicin delivery system for acute myeloid leukaemia (AML) and their selective therapeutics

The vacuoles in Saccharomyces cerevisiae are the key players digesting the waste within the cell. This functional organelle corresponding to the lysosome of mammalians contains acidic hydrolases and specific membrane proteins. Vacuoles have more than 60 hydrolytic enzymes and can easily be modified by genetic engineering. In previous study, we optimised the encapsulation condition with appropriate time and concentration and confirmed the use of vacuole as drug delivery carrier for acute myeloid leukaemia treatment. In this study, recombinant vacuole that could target the acute myeloid leukaemia cell line was constructed. The vacuoles derived from genetic engineered yeast were decorated with targeting peptide that has specific affinity with TLR2 on AML cell membrane. The anti-cancer efficacy of AML targeting vacuoles carriers with encapsulated daunorubicin was shown to be higher than normal vacuole carriers and the crude daunorubicin. The results confirmed that target selective chemotherapy using the vacuole drug delivery system is effective and offers potential for cancer therapy.

Melanin Treatment Effect of Vacuoles-Zinc Oxide Nanoparticles Combined with Ascorbic Acid

Currently, ascorbic acid (AA) is widely used as a skin whitening material, but, AA, an unstable hydrophilic molecule, cannot penetrate the skin easily, due to the hydrophobic character of the stratum corneum. Therefore, we conjugated AA with hydrated zinc oxide-an inorganic matrix with positive surface charge, to improve the stability of AA. The metal-conjugated-ascorbic acid (ZnAA) was then combined with yeast vacuole through the vacuolar membrane proteins that relate to metal transportation to create an enhanced vacuole that contained ZnAA. The characteristics of vacuole with ZnAA (ZnAA_Vac) were next examined by various tests that included X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray (EDX) analysis. Furthermore, the ability of ZnAA_Vac to degrade melanin was confirmed in both melanoma cell line B16F10, and the artificial human skin MelanoDerm. The results showed that ZnAA_Vac possessed a higher depigmenting effect than the wild-type vacuole or ascorbic acid by reducing 75% of melanin color. Interestingly, ZnAA_Vac was found to be harmless, and did not cause any cytotoxicity to the cells. Overall, ZnAA_Vac is expected to provide a robust, harmless, and effective whitening agent for the skin.

Lysosomes in Stem Cell Quiescence: A Potential Therapeutic Target in Acute Myeloid Leukemia

Lysosomes are cellular organelles that regulate essential biological processes such as cellular homeostasis, development, and aging. They are primarily connected to the degradation/recycling of cellular macromolecules and participate in cellular trafficking, nutritional signaling, energy metabolism, and immune regulation. Therefore, lysosomes connect cellular metabolism and signaling pathways. Lysosome's involvement in the critical biological processes has rekindled clinical interest towards this organelle for treating various diseases, including cancer. Recent research advancements have demonstrated that lysosomes also regulate the maintenance and hemostasis of hematopoietic stem cells (HSCs), which play a critical role in the progression of acute myeloid leukemia (AML) and other types of cancer. Lysosomes regulate both HSCs' metabolic networks and identity transition. AML is a lethal type of blood cancer with a poor prognosis that is particularly associated with aging. Although the genetic landscape of AML has been extensively described, only a few targeted therapies have been produced, warranting the need for further research. This review summarizes the functions and importance of targeting lysosomes in AML, while highlighting the significance of lysosomes in HSCs maintenance.

Identification of m6A-Related lncRNAs Associated With Prognoses and Immune Responses in Acute Myeloid Leukemia

Background: Acute myeloid leukemia (AML) remains the most common type of hematopoietic malignancy in adults and has an unfavorable outcome. Herein, we aimed to construct an N6-methylandenosine (m6A)-related long noncoding RNAs (lncRNAs) signature to accurately predict the prognosis of patients with AML using the data downloaded from The Cancer Genome Atlas (TCGA) database.

Methods: The RNA-seq and clinical data were obtained from the TCGA AML cohort. First, Pearson correlation analysis was performed to identify the m6A-related lncRNAs. Next, univariate Cox regression analysis was used to determine the candidate lncRNAs with prognostic value. Then, feature selection was carried out by Least absolute shrinkage and selection operator (LASSO) analysis, and seven eligible m6A-related lncRNAs were included to construct the prognostic risk signature. Kaplan–Meier and receiver operating characteristic (ROC) curve analyses were performed to evaluate the predictive capacity of the risk signature both in the training and testing datasets. A nomogram was used to predict 1-year, 2-year, and 3-year overall survival (OS) of AML patients. Next, the expression levels of lncRNAs in the signature were validated in AML samples by qRT-PCR. Functional enrichment analyses were carried out to identify probable biological processes and cellular pathways. The ceRNA network was developed to explore the downstream targets and mechanisms of m6A-related lncRNAs in AML.

Results: Seven m6A-related lncRNAs were identified as a prognostic signature. The low-risk group hold significantly prolonged OS. The nomogram showed excellent accuracy of the signature for predicting 1-year, 2-year and 3-year OS (AUC = 0.769, 0.820, and 0.800, respectively). Moreover, the risk scores were significantly correlated with enrichment in cancer hallmark- and malignancy-related pathways and immunotherapy response in AML patients.

Conclusion: We developed and validated a novel risk signature with m6A-related lncRNAs which could predict prognosis accurately and reflect the immunotherapy response in AML patients.

Enhanced immune response by vacuoles isolated from Saccharomyces cerevisiae in RAW 264.7 macrophages

Vacuoles are membrane vesicles in eukaryotic cells, the digestive system of cells that break down substances absorbed outside the cell and digest the useless components of the cell itself. Researches on anticancer and intractable diseases using vacuoles are being actively conducted. The practical application of the present study to animals requires the determination of the biocompatibility of vacuole. In the present study, we evaluated the effects of vacuoles isolated from Saccharomyces cerevisiae in RAW 264.7 cells. This showed a significant increase in the production of nitric oxide (NO) produced by macrophage activity. Using Reactive Oxygen Species (ROS) assay, we identified that ROS is increased in a manner dependent on vacuole concentration. Western blot analysis showed that vacuole concentration-dependently increased protein levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2). Therefore, iNOS expression was stimulated to induce NO production. In addition, pro-inflammatory cytokines levels promoted, such as interleukin (IL) 6 (IL-6) and tumor necrosis factor (TNF) α (TNF-α). In summary, vacuoles activate the immune response of macrophages by promoting the production of immune-mediated transporters NO, ROS, and pro-inflammatory cytokines.

Lysosomes in acute myeloid leukemia: potential therapeutic targets?

Lysosomes, since their discovery, have been primarily known for degrading cellular macromolecules. However, in recent studies, they have begun to emerge as crucial regulators of cell homeostasis. They are at the crossroads of catabolic and anabolic pathways and are intricately involved in cellular trafficking, nutrient signaling, energy metabolism, and immune regulation. Their involvement in such essential cellular functions has renewed clinical interest in targeting the lysosome as a novel way to treat disease, particularly cancer. Acute myeloid leukemia (AML) is an aggressive blood cancer with a low survival probability, particularly in older patients. The genomic landscape of AML has been extensively characterized but few targeted therapies (with the exception of differentiation therapy) can achieve a long-term cure. Therefore, there is an unmet need for less intensive and more tolerable therapeutic interventions. In this review, we will give an overview on the myriad of functions performed by lysosomes and their importance in malignant disease. Furthermore, we will discuss their relevance in hematopoietic cells and different ways to potentially target them in AML.