Xiu-Zhen Zhang

Excessive accumulation of reactive oxygen species (ROS) in the brain and the resulting oxidative stress are core drivers of neurodegenerative processes. Human dental pulp stem cells (DPSCs) secrete small extracellular vesicles (sEVs) abundant in functional microRNAs, which possess prominent regenerative capacity. The present study investigated the neuroprotective effects of DPSC-derived sEVs (DPSC-sEVs) against oxidative injury in SH-SY5Y neuronal cells and elucidated the underlying molecular mechanisms. DPSC identity was confirmed via flow cytometric immunophenotyping and multipotent differentiation assays. sEVs were isolated from DPSC-conditioned medium and characterized by transmission electron microscopy, nanoparticle tracking analysis and detection of canonical exosomal markers (CD63, CD81, and TSG101). An in vitro model of neuronal oxidative stress was established using hydrogen peroxide (H₂O₂). Cell viability, apoptosis, intracellular ROS levels, and lactate dehydrogenase (LDH) release, as well as the levels/activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA), were assessed to evaluate the protective effects of sEVs. Candidate miRNAs in sEVs were screened by quantitative real-time PCR (qPCR). Direct binding of miR-100-5p to the 3′ untranslated region (3′UTR) of mammalian target of rapamycin (mTOR) was verified via dual-luciferase reporter assay. Autophagic activity was evaluated by immunoblotting and immunofluorescence staining of LC3B/p62. Pretreatment with DPSC-sEVs significantly ameliorated H₂O₂-induced neuronal oxidative damage and apoptosis. Mechanistically, sEV miR-100-5p conferred neuroprotective and antioxidant properties by inhibiting mTOR signaling and activating autophagy in vitro. Blockade of miR-100-5p or pharmacological inhibition of autophagy by 3-methyladenine (3-MA) largely abolished these protective effects. In conclusion, DPSC-sEVs attenuate neuronal oxidative stress by reversing mTOR-mediated suppression of autophagy, and this protective effect is dependent on the function of miR-100-5p in SH-SY5Y cells. The miR-100-5p/mTOR/autophagy axis mediates the neuroprotective effects of DPSC-sEVs, representing a promising therapeutic candidate for oxidative stress-associated neurodegenerative diseases that merits further in vivo validation.

Tumor-associated macrophages (TAMs) are inflammatory cells that are important components of the tumor microenvironment. TAMs are functionally heterogeneous and divided into two main subpopulations with distinct and opposite functions: M1 and M2 macrophages. The secretory function of TAMs is essential for combating infections, regulating immune responses, and promoting tissue repair. Extracellular vesicles (EVs) are nanovesicles that are secreted by cells. They play a crucial role in mediating intercellular information transfer between cells. EVs can be secreted by almost all types of cells, and they contain proteins, microRNAs, mRNAs, and even long non-coding RNAs (lncRNAs) that have been retained from the parental cell through the process of biogenesis. EVs can influence the function and behavior of target cells by delivering their contents, thus reflecting, to some extent, the characteristics of their parental cells. Here, we provide an overview of the role of M1 macrophages and their EVs in cancer therapy by exploring the impact of M1 macrophage-derived EVs (M1-EVs) on tumors by transferring small microRNAs. Additionally, we discuss the potential of M1-EVs as drug carriers and the possibility of reprogramming M2 macrophages into M1 macrophages for disease treatment. We propose that M1-EVs play a crucial role in cancer therapy by transferring microRNAs and loading them with drugs. Reprogramming M2 macrophages into M1 macrophages holds great promise in the treatment of cancers.

The interaction between a tumor and the tumor microenvironment (TME) plays a key role in tumorigenesis and tumor progression. Ubiquitination, a crucial post‑translational modification for regulating protein degradation and turnover, plays a role in regulating the crosstalk between a tumor and the TME. Thus, identifying the roles of ubiquitination in the process may assist researchers to investigate the mechanisms underlying tumorigenesis and tumor progression. In the present review article, new insights into the substrates for ubiquitination that are involved in the regulation of hypoxic environments, angiogenesis, chronic inflammation‑mediated tumor formation, and the function of cancer‑associated fibroblasts and infiltrating immune cells (tumor‑associated macrophages, T‑cells, myeloid‑derived suppressor cells, dendritic cells, and natural killer cells) are summarized. In addition, the potential targets of the ubiquitination proteasome system within the TME for cancer therapy and their therapeutic effects are reviewed and discussed.

Due to synergistic effects, combinatorial drugs are widely used for treating complex diseases. However, combining drugs and making them synergetic remains a challenge. Genetic disease genes are considered a promising source of drug targets with important implications for navigating the drug space. Most diseases are not caused by a single pathogenic factor, but by multiple disease genes, in particular, interacting disease genes. Thus, it is reasonable to consider that targeting epistatic disease genes may enhance the therapeutic effects of combinatorial drugs. In this study, synthetic lethality gene pairs of tumors, similar to epistatic disease genes, were first targeted by combinatorial drugs, resulting in the enrichment of the combinatorial drugs with cancer treatment, which verified our hypothesis. Then, conventional epistasis detection software was used to identify epistatic disease genes from the genome wide association studies (GWAS) dataset. Furthermore, combinatorial drugs were predicted by targeting these epistatic disease genes, and five combinations were proven to have synergistic anti-cancer effects on MCF-7 cells through cell cytotoxicity assay. Combined with the three-dimensional (3D) genome-based method, the epistatic disease genes were filtered and were more closely related to disease. By targeting the filtered gene pairs, the efficiency of combinatorial drug discovery has been further improved.

This study aims at evaluating the anticancer effects of berberine hydrochloride (berberine) and d -limonene, alone and in combination, on human gastric carcinoma cell line MGC803 to determine whether berberine and d -limonene work synergistically and elucidate their mechanisms. MGC803 cells were treated with berberine and d -limonene, alone and in combination, for 24–48 h. The inhibitory effects of these drugs on growth were determined by MTT assay. The combination index and drug reduction index were calculated with the Chou–Talalay method based on the median-effect principle. Flow cytometry and laser scanning confocal microscopy were employed to evaluate the effects of both drugs on cell-cycle perturbation and apoptosis, generation of reactive oxygen species (ROS), mitochondrial membrane potential, and expression of Bcl-2 and caspase-3 in MGC803 cells. Berberine or d -limonene alone can inhibit the growth of MGC803 cells in a dose- and time-dependent manner. Berberine and d -limonene at a combination ratio of 1:4 exhibited a synergistic effect on anti-MGC803 cells. The two drugs distinctly induced intracellular ROS generation, reduced the mitochondrial transmembrane potential (ΔΨ m ), enhanced the expression of caspase-3, and decreased the expression of Bcl-2. The combination of berberine and d -limonene showed more remarkable effects compared with drugs used singly in MGC803 cells. The combination of berberine and d -limonene exerted synergistic anticancer effects on MGC803 cells by cell-cycle arrest, ROS production, and apoptosis induction through the mitochondria-mediated intrinsic pathway.