Background: Although cisplatin-based chemotherapy has been used as the first-line treatment for ovarian cancer (OC), tumor cells develop resistance to cisplatin during treatment, causing poor prognosis in OC patients. Studies have demonstrated that overactivation of the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway is involved in tumor chemoresistance and that overexpression of microRNA-497 (miR497) may overcome OC chemotherapy resistance by inhibiting the mTOR pathway. However, the low transcriptional efficiency and unstable chemical properties of miR497 limit its clinical application. Additionally, triptolide (TP) was confirmed to possess a superior killing effect on cisplatin-resistant cell lines, partially through inhibiting the mTOR pathway. Even so, the clinical applications of TP are restricted by serious systemic toxicity and weak water solubility.Results: Herein, whether the combined application of miR497 and TP could further overcome OC chemoresistance by synergically suppressing the mTOR signaling pathway was investigated. Bioinspired hybrid nanoparticles formed by the fusion of CD47-expressing tumor exosomes and cRGD-modified liposomes (miR497/TP-HENPs) were prepared to codeliver miR497 and TP. In vitro results indicated that the nanoparticles were efficiently taken up by tumor cells, thus significantly enhancing tumor cell apoptosis. Similarly, the hybrid nanoparticles were effectively enriched in the tumor areas and exerted significant anticancer activity without any negative effects in vivo. Mechanistically, they promoted dephosphorylation of the overactivated PI3K/AKT/mTOR signaling pathway, boosted reactive oxygen species (ROS) generation and upregulated the polarization of macrophages from M2 to M1 macrophages.Conclusion: Overall, our findings may provide a translational strategy to overcome cisplatin-resistant OC and offer a potential solution for the treatment of other cisplatin-resistant tumors.Graphical
6 September 2019 in Signal Transduction and Targeted Therapy
Hepatocellular carcinoma (HCC) is a malignancy with a poor prognosis. Surgery combined with chemotherapy has been recommended as a curative regimen for HCC. Nevertheless, the anticancer mechanisms of chemicals in hepatocellular carcinoma remain unclear. Pyroptosis is a type of programmed necrosis, and its mechanism in hepatocellular carcinoma is poorly understood. The efficacy and mechanism of arsenic trioxide nanoparticles in the treatment of HCC were explored in this research. Arsenic trioxide alone and arsenic trioxide nanoparticles were conveniently administered to mice intratumorally using a needle. Compared with As2O3, As2O3nanoparticles (As2O3-NPs) showed better inhibition, promoted greater LDH release, and induced cell morphology indicative of pyroptosis in vitro. Compared with the free drug, As2O3-NPs increased GSDME-N expression and decreased Dnmt3a, Dnmt3b, and Dnmt1 expression in Huh7 cells. In vivo, As2O3-NPs induced a significant decrease in the expression of Dnmt3a, Dnmt3b and Dnmt1, but significantly upregulated the expression of GSDME-N (gasdermin E (GSDME) was originally found to be related to deafness; recently, it has been defined as a gasdermin family member associated with pyroptosis). As2O3-NPs inhibited tumor growth more strongly than As2O3or control, a finding likely attributed to the downregulation of PCNA and DNMT-related proteins and the upregulation of GSDME-N.
Export Background and Aims: Gut microbiota are recognized to be important for anticancer therapy, yet the underlying mechanism is not clear. Here, through the analysis of clinical samples, we identify the mechanism by which the gut microbial metabolite butyrate inhibits hepatocellular carcinoma (HCC) and then explore new strategies for HCC treatment. Approach and Results: In our study, we demonstrate that gut microbial metabolite butyrate improves anticancer therapy efficacy by regulating intracellular calcium homeostasis. Using liquid chromatography-mass spectrometry analysis, we found that butyrate metabolism is activated in HCC patients compared with healthy individuals. Butyrate levels are lower in the plasma of HCC patients by gas chromatography mass spectrometry (GC-MS) analysis. Butyrate supplementation or depletion of short-chain Acyl-CoA dehydrogenase (ACADS), a key enzyme for butyrate metabolism, significantly inhibits HCC proliferation and metastasis. Profiling analysis of genes upregulated by butyrate supplementation or ACADS knockdown reveals that calcium signaling pathway is activated, leading to dysregulation of intracellular calcium homeostasis and production of reactive oxygen species (ROS). Butyrate supplementation improves the therapy efficacy of a tyrosine kinase inhibitor sorafenib. Based on these findings, we developed butyrate and sorafenib co-encapsulated mPEG-PLGA-PLL (PEAL) nanoparticles (NPs) coated with anti-GPC3 antibody ([email protected]) to prolong the retention time of drugs and enhance drug targeting, leading to high anticancer efficacy. [email protected] NPs significantly reduce HCC progression. In addition, [email protected] NPs display excellent HCC targeting with excellent safety. Conclusions: In conclusion, our findings provide new insight into the mechanism by which the gut microbial metabolites inhibit HCC progression, suggesting a translatable therapeutics approach to enhance the clinical targeted therapeutic efficacy.
Advanced liver cancer is the most fatal malignant cancer, and the clinical outcomes of treatment are not very satisfactory due to the complexity and heterogeneity of the tumor. Combination therapy can efficiently enhance tumor treatment by stimulating multiple pathways and regulating the tumor immune microenvironment. Nanodrug delivery systems have become attractive candidates for combined strategies for liver cancer treatment. This study reports a nano ultrasound contrast agent (arsenic trioxide (ATO)/PFH NPs@Au‐cRGD) to integrate diagnosis and treatment for efficient ultrasound imaging and liver cancer therapy. This nanodrug delivery system promotes tumor‐associated antigens release through ATO‐induced ferroptosis and photothermal‐induced immunogenic cell death, enhancing the synergistic effects of ATO and photothermal therapy in human Huh7 and mouse Hepa1–6 cells. This drug delivery system successfully activates the antitumor immune response and promotes macrophage M1 polarization in tumor microenvironment with low side effects in subcutaneous and orthotopic liver cancer. Furthermore, tumor metastasis is inhibited and long‐term immunological memory is also established in orthotopic liver cancer when the nanodrug delivery system is combined with anti‐programmed death‐ligand 1 (PD‐L1) immunotherapy. This safe nanodrug delivery system can enhance antitumor therapy, inhibit lung metastasis, and achieve visual assessment of therapeutic efficacy, providing substantial potential in clinic applications for liver cancer.