Identification of Fangchinoline as a novel autophagy inhibitor with an adjuvant of chemotherapy against lung cancer.

Autophagy is a fundamental recycling pathway that enhances cellular resilience, promoting survival. However, this survival mechanism can impede anti-cancer treatment strategies designed to induce cell death. In this study, we identified a novel autophagy inhibitor, Fangchinoline (Fan) isolated from the traditional Chinese medicine Stephania tetrandra. We speculated that when Fan blocks autophagy, cancer cells lose substantial self-preservation abilities during treatment. Firstly, we examined in detail the mechanism through which Fan inhibits autophagy. Specifically, Fan induced a significant increase in autophagosomes, as indicated by GFP-LC3 labeling, confirmed by the up-regulation of LC3-II. The autophagy receptor protein p62 was also up-regulated, suggesting a potential inhibition of autophagy flux. We further ruled out the possibility of fusion barriers between lysosomes and autophagosomes, as confirmed by their co-localization in double fluorescence staining. However, the lysosomal acid environment might be compromised, as suggested by the diminished fluorescence of acidity-sensitive dyes in the lysosomes and the corresponding decrease in mature forms of lysosomal cathepsin. To test the anti-cancer potential of Fan, we combined it with Cisplatin (Cis) or Paclitaxel (PTX) for lung cancer cell treatment. This combined treatment demonstrated a synergistically enhanced killing effect. These promising anti-tumor results were also replicated in a xenografted tumor model. The significance of this research lies in the identification of Fan as a potent autophagy inhibitor and its potential to enhance the efficacy of existing anti-cancer drugs. By unraveling the mechanisms of Fan's action on autophagy and demonstrating its synergistic effect in combination therapies, our study provides valuable insights for developing novel strategies to overcome autophagy-mediated resistance in cancer treatment.

Dioscin potentiates the antitumor effect of suicide gene therapy in melanoma by gap junction intercellular communication-mediated antigen cross-presentation.

Dioscin (Dio), steroid saponin, exists in several medicinal herbs with potent anticancer efficacy. This study aimed to explore the effect of Dio on the immune-related modulation and synergistic therapeutic effects of the herpes simplex virus thymidine kinase/ganciclovir (HSV-Tk/GCV) suicide gene therapy system in murine melanoma, thereby providing a research basis to improve the potential immunomodulatory mechanism underlying combination therapy. Using both in vitro and in vivo experiments, we confirmed the immunocidal effect of Dio-potentiated suicide gene therapy on melanoma. The results showed that Dio upregulated connexin 43 (Cx43) expression and improved gap junction intercellular communication (GJIC) in B16 cells while increasing the cross-presentation of antigens by dendritic cells (DCs), eventually promoting the activation and antitumor immune killing effects of CD8+ T lymphocytes. In contrast, inhibition or blockade of the GJIC function (overexpression of mutant Cx43 tumor cells/Gap26) partially reversed the potentiating effect. The significant synergistic effect of Dio on HSV-Tk/GCV suicide gene therapy was further investigated in a B16 xenograft mouse model. The increased number and activation ratio of CD8+ T lymphocytes and the levels of Gzms-B, IFN-γ, and TNF-α in mice reconfirmed the potential modulatory effects of Dio on the immune system. Taken together, Dio targets Cx43 to enhance GJIC function, improve the antigens cross-presentation of DCs, and activate the antitumor immune effect of CD8+ T lymphocytes, thereby providing insights into the potential immunomodulatory mechanism underlying combination therapy.

Molybdenum Selenide/Porous Carbon Nanomaterial Heterostructures with Remarkably Enhanced Light-Boosting Peroxidase-like Activities.

Nanozymes have emerged as a fascinating nanomaterial with enzyme-like characteristics for addressing the limitations of natural enzymes. Nevertheless, how to improve the relatively low catalytic activity still remains challenging. Herein, a facile recrystallizing salt template-assisted chemical vapor deposition method was utilized to synthesize MoSe2/PCN heterostructures. This heterostructure displays remarkably enhanced light boosting peroxidase-like activities. Notably, the maximal reaction velocity of this heterostructure attains 17.81 and 86.89 µM min-1 [for o-phenylenediamine (OPD) and 3,3'5,5'-tetramethylbenzidine (TMB), respectively]. Moreover, various characterization means were performed to explore the mechanism deeply. It is worth mentioning that the photoinduced electrons generated by the heterostructure directly react with H2O2 to yield plentiful •OH for the effective oxidation of OPD and TMB. Therefore, this work offers a promising approach for improving peroxidase-like activity by light stimulation and actuating the development of enzyme-based applications.

Preparation of phytosteryl ornithine ester hydrochloride and improvement of its bioaccessibility and cholesterol-reducing activity in vitro.

In this work, synthesis of phytosteryl ornithine ester hydrochloride was studied for the first time using an intermediate phytosteryl N,N'-bis[tert-butoloxycarbonyl(BOC)]-ornithine ester. This method also involved esterification of phytosterols with N,N'-bis(BOC)-ornithine and deprotection. The maximum yield was 90% and deprotection of BOC group was more than 99% using the HCl/ethyl acetate method. As a result, thermal stability and water solubility as well as emulsifying activity and stability of phytosterols were improved through coupling with ornithine, which is favorable for their application in water-based food systems. We also observed increased bioaccessibility of phytosteryl ornithine hydrochloride (4.5%) and 65% of phytosteryl ornithine hydrochloride was hydrolyzed in vitro. These results indicated that ornithine phytosteryl ester hydrochloride can reduce dissolution capacity of cholesterol in vitro, representing improved cholesterol-reducing activity, which will further expand the applications of phytosteryl ornithine ester hydrochloride.