Biomimetic nanoparticles blocking autophagy for enhanced chemotherapy and metastasis inhibition via reversing focal adhesion disassembly

Background Autophagy is a conserved catabolic process, which plays an important role in regulating tumor cell motility and degrading protein aggregates. Chemotherapy-induced autophagy may lead to tumor distant metastasis and even chemo-insensitivity in the therapy of hepatocellular carcinoma (HCC). Therefore, a vast majority of HCC cases do not produce a significant response to monotherapy with autophagy inhibitors. Results In this work, we developed a biomimetic nanoformulation (TH-NP) co-encapsulating Oxaliplatin (OXA)/hydroxychloroquine (HCQ, an autophagy inhibitor) to execute targeted autophagy inhibition, reduce tumor cell migration and invasion in vitro and attenuate metastasis in vivo. The tumor cell-specific ligand TRAIL was bioengineered to be stably expressed on HUVECs and the resultant membrane vesicles were wrapped on OXA/HCQ-loaded PLGA nanocores. Especially, TH-NPs could significantly improve OXA and HCQ effective concentration by approximately 21 and 13 times in tumor tissues compared to the free mixture of HCQ/OXA. Moreover, the tumor-targeting TH-NPs released HCQ alkalized the acidic lysosomes and inhibited the fusion of autophagosomes and lysosomes, leading to effective blockade of autophagic flux. In short, the system largely improved chemotherapeutic performance of OXA on subcutaneous and orthotopic HCC mice models. Importantly, TH-NPs also exhibited the most effective inhibition of tumor metastasis in orthotopic HCCLM3 models, and in the HepG2, Huh-7 or HCCLM3 metastatic mice models. Finally, we illustrated the enhanced metastasis inhibition was attributed to the blockade or reverse of the autophagy-mediated degradation of focal adhesions (FAs) including E-cadherin and paxillin. Conclusions TH-NPs can perform an enhanced chemotherapy and antimetastatic effect, and may represent a promising strategy for HCC therapy in clinics. Graphical Abstract

Biomimetic Nanoparticles Blocking Autophagy for Enhanced Chemotherapy and Metastasis Inhibition via Reversing Focal Adhesion Disassembly

BackgroundAutophagy is a conserved catabolic process, which plays an important role in regulating tumor cell motility and degrading protein aggregates. Chemotherapy-induced autophagy may lead to tumor distant metastasis and even chemo-insensitivity in the therapy of hepatocellular carcinoma (HCC). However, a vast majority of HCC cases do not produce a significant response to monotherapy with autophagy inhibitors. ResultsIn this work, we develop a biomimetic co-delivery nanoformulation (TH-NP) co-encapsulating Oxaliplatin (OXA)/HCQ (hydroxychloroquine, an autophagy inhibitor) to execute targeted autophagy inhibition, reduce tumor cell migration and invasion in vitro and attenuate metastasis in vivo. Especially, TH-NPs can significantly improve OXA and HCQ concentration with approximately 21 and 13-fold increment in tumor tissues compared to the free mixture of HCQ/OXA. Moreover, the tumor-targeting TH-NPs release HCQ can alkalize the acidic lysosomes and thus inhibit the fusion of autophagosomes and lysosomes, leading to most effective blockade of autophagic flux compared to various controls. This largely improves chemotherapeutic performance of OXA in subcutaneous and orthotopic HCC mouse models. Importantly, TH-NPs also exhibit the most effective inhibition of tumor metastasis in orthotopic HCCLM3 models, and in the HepG2, Huh-7 or HCCLM3 metastatic mouse models. Then, we illustrate the enhanced metastasis inhibition is attributed to the blockade or reverse of the autophagy-mediated degradation of focal adhesions (FAs) including E-cadherin and paxillin. ConclusionsTH-NPs can perform an enhanced chemotherapy and antimetastatic effect, and may represent a promising strategy for HCC therapy in clinics.

Antimetastatic effect of organotin compounds on the model of melanoma B16 in the experiment.

e21564 Background: Melanoma is an extremely malignant tumor. The unfavorable prognosis in the treatment of patients is mainly due to aggressive metastasis of the tumor in various ways: hematogenic, lymphogenic and lymphohematogenic. Metastatic melanoma cells are relatively drug - resistant. Despite some successes in the treatment of melanoma, the search for new antimetastatic substances remains an urgent task of experimental pharmacology and oncology. Organotin compounds were studied by us as promising candidates for antimetastatic agents. Methods: The study was conducted on experimental C57BL/6 mice (n =72, each cohort contained 12 mice) with B16 melanoma (subcutaneous transplantation) to determine the intensity of metastasis in the presence of the cytotoxic organotin compound dimethyltin bis (3,5-di-tert-butyl-4-hydroxyphenylthiolate) [1-3] (Me3). All manipulations were carried out in accordance with the European Convention for the Protection of Vertebrates Used for Experimental and Other Scientific Purposes (ETS 123). Female mice (8 weeks of age, weighing 21-22 g) were administered intraperitoneal 1% aqueous gelatin solution of organotin Me3 daily for 5 days. The total doses in the first series of the experiment were 150, 250, 375 mg/kg (I, II, III cohorts and IV control group), which allowed us to choose the most effective dose of Me3. After that, in the second series of experiments, the metastasis inhibition index was evaluated in group V (total dose 375 mg/kg) and control group VI. The animals were euthanized on the 18th day after the tumor was inoculated. Results: It was shown that when administered intraperitoneal to mice, Me3 did not inhibit the growth of B16 melanoma in any of the groups. The results showed that the average life expectancy of animals in the experimental group III with the introduction of Me3 at a dose of 375 mg/kg significantly increased and amounted to 30.1±2.5 days, in control mice of group IV-21.8±2.6 days. In the second series of the experiment, after 18 days, the index of metastasis inhibition was almost twice lower (54%) in group V than in the control group (VI). Conclusions: It is concluded that the overall result of this study clearly demonstrates that the organotin compound dimethyltin bis (3,5-di-tert-butyl-4-hydroxyphenylthiolate) (Me3) is an effective antimetastatic agent in transplanted experimental mouse melanoma B16 at a total dose of 375 mg/kg.

A Multifunctional Biodegradable Prussian blue Analogue for Synergetic Photothermal/Photodynamic/Chemodynamic therapy and Intrinsic Tumor Metastasis Inhibition

Background To date, various Prussian blue analogues (PBA) have been prepared for biomedical applications due to their unique structural advantages. However, the safety and effectiveness of tumor treatment still need further exploration. Results This contribution reports a facile synthesis of novel PBA with superior tumor synergetic therapy effects and a detailed mechanistic evaluation of their intrinsic tumor metastasis inhibition activity. The as-synthesized PBA have a uniform cube structure with a diameter of approximately 220 nm and showed high near infrared light (NIR) photoreactivity, photothermal conversion efficiency (41.44%) and photodynamic effect. Additionally, PBA could lead to chemodynamic effect which caused by Fenton reaction and ferroptosis. The combined therapy strategy of PBA exhibit notable tumor ablation properties due to photothermal therapy (PTT)/photodynamic therapy (PDT)/ chemodynamic therapy (CDT) effect without obvious toxicity in vivo. The PBA also demonstrate potential as a contrast agent for magnetic resonance imaging (MRI) and photoacoustic (PA) imaging. More importantly, careful investigations reveal that PBA displays excellent biodegradation and anti-metastasis properties. Further exploration of this PBA implies that its underlying mechanism of intrinsic tumor metastasis inhibition activity can be attributed to modulation of epithelial mesenchymal transition (EMT) expression. Conclusions The considerable potential exhibits by as-synthesized PBA make it an ideal candidate as a synergetic therapeutic agent for tumor treatment.

Combination of Mitochondrial Targeting Doxorubicin with Bcl-2 Function Converting Peptide NuBCP-9 for Synergistic Breast Cancer Metastasis Inhibition

Distant organ metastasis is the main cause of death in breast cancer patients. Evidences have shown that mitochondria also play a crucial role in tumor metastasis, except for as apoptosis...