Nano-herb medicine and PDT induced synergistic immunotherapy for colon cancer treatment.

A variety of therapies have been developed and used for the treatment of colon cancer, however, the high mortality rate remains high and more effective strategies are still in urgent needs. In this study, an immunotherapy approach that is composed of innate immune activator Astragaloside III (As) and the photodynamic therapy (PDT) reagent chlorine e6 (Ce6) ((As + Ce6)@MSNs-PEG), was developed for colon cancer treatment. We showed that (As + Ce6)@MSNs-PEG could effectively activate NK cells and inhibit the proliferation of tumor cells in vitro. It could also effectively reach tumor sites, induce infiltration of immune cells into the tumor, and enhance the cytotoxicity of natural killer cells and CD8+ T cells in vivo. Without obvious side effects, (As + Ce6)@MSNs-PEG treatment significantly inhibited tumor growth and extended the lifespan of tumor-bearing mice. Further results revealed that treatment of (As + Ce6)@MSNs-PEG led to enhanced IFN secretion by immune cells and increased T-box transcription factor (T-bet), which is highly expressed by T cells. Therefore, (As + Ce6)@MSNs-PEG may serve as an effective and safe platform for combinatory use with nano-herb medicine and PDT to provide a new therapy for colon cancer treatment.

Nanoparticle-based diagnostic and therapeutic systems for brain tumors.

Brain tumors, especially the most prevalent and aggressive glioblastoma, remain among the deadliest of all types of cancer due to inefficient theranostic options. They have a limited therapeutic window because of physiological barriers such as the blood-brain barrier (BBB), blood cerebrospinal fluid (CSF) barrier and interstitial fluid (ISF) that restrict the penetration of imaging probes and therapeutic drugs. In order to achieve more accurate brain tumor diagnosis and better therapeutic effects, many strategies have been explored; among them multifunctional nanoparticles offer a novel and potential opportunity depending on their size effects, and their optical, magnetic, photodynamic and other properties. After modification, nanoparticles can cross the BBB and specifically accumulate in the tumor site, thereby achieving accurate tumor imaging and drug release. This review is focused on various types of nanoparticles that are being used for improving nano-carriers of diagnostic and therapeutic agents into brain tumors and also provides a concise summary of various multifunctional theranostic strategies, particularly in clinical applications. In this manner, we provide evidence for the key role of nanoparticle based diagnosis and therapy systems in brain tumors.

Astragaloside III Enhances Anti-Tumor Response of NK Cells by Elevating NKG2D and IFN-γ.

Natural killer (NK) cells play an irreplaceable role in the development of colon cancer, in which antitumor function of NK cells was impaired. Astragaloside III is a natural compound from Astragalus that has been shown to have immunomodulatory effects in various systems. However, few studies have evaluated the antitumor effects of Astragaloside III through stimulating systemic immunity and regulating NK cells. In this study, flow cytometry, immunohistochemical analysis, and immunofunctional assays were performed to elucidate the functions of Astragaloside III in restoring antitumor function of NK cells. We demonstrated that Astragaloside III significantly elevated the expression of natural killer group 2D (NKG2D), Fas, and interferon-γ (IFN-γ) production in NK cells, leading to increased tumor-killing ability. Experiments in cell co-culture assays and CT26-bearing mice model further confirmed that Astragaloside III could effectively impede tumor growth by increasing infiltration of NK cells into tumor and upregulating the antitumor response of NK cells. We further revealed that Astragaloside III increased IFN-γ secretion of NK cells by enhancing the expression of transcription factor T-bet. In conclusion, the effective anti-tumor function of Astragaloside III was achieved through up-regulation of the immune response of NK cells and elevation of NKG2D, Fas, and IFN-γ production.