The tumor microenvironment (TME) is a complex and dynamic entity, comprising stromal cells, immune cells, blood vessels and extracellular matrix, which is intimately associated with the occurrence and development of cancers, as well as their therapy. Utilizing the shared characteristics of tumors, such as an acidic environment, enzymes and hypoxia, researchers have developed a promising cancer therapy strategy known as responsive release of nano-loaded drugs, specifically targeted at tumor tissues or cells. In this comprehensive review, we provide an in-depth overview of the current fundamentals and state-of-the-art intelligent strategies of TME-responsive nanoplatforms, which include acidic pH, high GSH levels, high-level adenosine triphosphate, overexpressed enzymes, hypoxia and reductive environment. Additionally, we showcase the latest advancements in TME-responsive nanoparticles. In conclusion, we thoroughly examine the immediate challenges and prospects of TME-responsive nanopharmaceuticals, with the expectation that the progress of these targeted nanoformulations will enable the exploitation, overcoming or modulation of the TME, ultimately leading to significantly more effective cancer therapy.
Toe1 (target of EGR1, member 1) is a 3′- exonuclease in the deadenylase family, essential for the maturation of small nuclear RNAs. Mutations in Toe1 are linked to pontocerebellar hypoplasia 7 (PCH7), a severe neurodegenerative syndrome affecting infants, characterized by progressive neurodegeneration, developmental delay, and genital abnormalities. The pathogenic mechanisms of PCH7 are unclear but are thought to involve abnormal neural stem cell (NSC) development during embryogenesis. This study investigates Toe1's role in NSC development using the C17.2 NSC line. Colony formation, EdU incorporation, and CFSE staining assays showed that Toe1 knockout inhibited C17.2 cell proliferation. Upon inducing differentiation, Toe1 knockout significantly reduced cell dendrites. Immunofluorescence, qPCR, and Western blot analyses indicated that Toe1 knockout suppressed the expression of neuronal marker βIII-tubulin and glial cell marker Gfap, thereby inhibiting C17.2 cell differentiation. Additionally, Toe1 knockout reduced the expression of Dll1 and Jag1, suggesting an inhibition of Notch signaling. High-throughput transcriptome sequencing revealed that Toe1 influenced calcium ion binding, ECM, and amino acid catabolism in undifferentiated C17.2 cells, and peptidase activity, chemotactic factors, ECM, and TNF signaling in differentiated cells. These findings underscore Toe1's critical regulatory role in NSC proliferation and differentiation, with significant implications for developing therapeutic targets for neurodegenerative diseases such as PCH7.