Deficiency of factor-inhibiting HIF creates a tumor-promoting immune microenvironment

Research progress of CD73-adenosine signaling regulating hepatocellular carcinoma through tumor microenvironment

Adenosine signaling pathway is a kind of signal regulation hub widely existing in human body, which is involved in a series of physiological processes such as energy supply of body cells. CD73 is a highly concerned signaling protein in purine adenosine pathway, and its role in tumor development and prognosis has been paid more and more attention in recent years, especially in hepatocellular carcinoma (HCC). In this paper, the specific mechanism by which CD73-adenosine signaling regulates tumor microenvironment (TME) of liver cancer tumors was analyzed in detail, highlighting the importance of this pathway as a therapeutic target to combat tumor immunosuppression and enhance the anti-tumor immune response to prevent and treat hepatocellular carcinoma (HCC). In addition, a variety of current targeted therapeutic strategies for adenosine metabolic pathways are summarized, including the development of new drugs in the stage of preclinical research and clinical trials, and the mechanism of action, implementation possibility, and clinical effects of these therapies are discussed. By summarizing the latest scientific research results, in this review, we attempt to paint a panorama of the mechanism of adenosine action in tumor immunotherapy, with the aim to provide a solid theoretical basis and practical guidance for subsequent research and clinical application, ultimately promoting the development of more accurate and efficient tumor immunotherapy.

Cascade-recharged macrophage-biomimetic ruthenium-based nanobattery for enhanced photodynamic-induced immunotherapy

Photodynamic-induced immunotherapy (PDI) is often hampered by low reactive oxygen species (ROS) yield, intra-tumor hypoxia, high glutathione (GSH) concentration, and immunosuppressive microenvironment. In view of this, a ruthenium (Ru)-based nanobattery (termed as IRD) with cascade-charged oxygen (O2), ROS, and photodynamic-induced immunotherapy by coordination-driven self-assembly of transition-metal Ru, photosensitizer indocyanine green (ICG), and organic ligand dithiobispropionic acid (DTPA). Then, IRD is camouflaged with macrophage membranes to obtain a nanobattery (termed as IRD@M) with targeting and immune evasion capabilities. Upon intravenous administration, IRD@M with a core-shell structure, nano diameter, and good stability can specifically hoard in tumor location and internalize into tumor cells. Upon disassembly triggered by GSH, the released Ru³⁺ not only catalyzes the conversion of endogenous hydrogen peroxide (H₂O₂) into O₂ to alleviate tumor hypoxia and reduce the expression of hypoxia-inducible factor-1α (HIF-1α), but also generates hydroxyl radicals (·OH) to elevate intracellular ROS levels. This process significantly enhances the photodynamic therapy (PDT) efficacy of the released ICG. Meanwhile, the released DTPA can significantly downregulate overexpressed GSH to reduce the elimination of ROS deriving from PDT by the exchange reaction of thiol-disulfide bond. It is also found that alleviating the hypoxic tumor microenvironment synergistically enhances the PDT efficacy, which in turn cascades to recharge the subsequent immune response, significantly improving the immunosuppressive tumor microenvironment and activating systemic tumor-specific immunity. Notably, in vitro and in vivo experimental results jointly confirm that such cascade-recharged macrophage-biomimetic Ru-based nanobattery IRD@M can achieve an obvious tumor elimination while results in a minimized side effect. Taken together, this work highlights a promising strategy for simple, flexible, and effective Ru-based immunogenic cell death (ICD) agents within PDI.

Discovery of ZG-2305, an Orally Bioavailable Factor Inhibiting HIF Inhibitor for the Treatment of Obesity and Fatty Liver Disease

Genetic loss of the 2-oxoglutarate oxygenase factor inhibiting hypoxia-inducible factor (FIH) enhances both glycolysis and aerobic metabolism. FIH is thus a potential target for adiposity control and improving hepatic steatosis. We describe development of a series of novel, potent, and selective FIH inhibitors that occupy both the FIH catalytic site and a recently defined tyrosine conformational-flip pocket. ZG-2305, with a Ki of 79.6 nM for FIH, manifests 38-fold selectivity over the hypoxia-inducible factor (HIF) prolyl hydroxylase PHD2. Oral administration of ZG-2305 in the western-diet induced obesity mouse model results in improved lipid accumulation and recovery from abnormal body weight/hepatic steatosis. Amelioration of nonalcoholic steatohepatitis (NASH) related pathological phenotypes in the HF-CDAA-diet induced NASH mouse model was observed. Preliminary preclinical studies indicate ZG-2305 has good pharmacokinetic properties and an acceptable safety profile. The results imply ZG-2305 is a promising candidate for treatment of obesity and fatty liver disease.

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.