Dendritic Polylysine with Paclitaxel and Triptolide Codelivery for Enhanced Cancer Ferroptosis through the Accumulation of ROS.

Recently, paclitaxel (PTX) was reported to increase intracellular lipid reactive oxygen species (ROS) levels, triggering cancer cell ferroptosis. Based on this, some efforts had been made to improve PTX treatment for non-small-cell lung cancer (NSCLC). Our previous studies demonstrated that triptolide (TPL) could improve the antitumor effect of PTX. Nevertheless, the poor solubility and side effects often limit the application of chemotherapy drugs. In this paper, we constructed a novel nanodrug delivery system (NDDS) chemosynthesis by PEGylated generation 3 (G3) dendritic polylysine coloaded with PTX and TPL (PTX-TPL-PEG-PLL, PTPP), which was endowed with the ability of tumor targeting and favorable solubility. In addition, we demonstrated that TPL could induce ROS generation by regulating the NF-κB signaling pathway to enhance the ferroptosis-induced effect of PTX. Besides, ferroptosis induced by PTPP could improve chemoresistance through inhibiting the level of P-gp, GPX4, and SLC7A11. Furthermore, we determined that ferroptosis may strengthen the immune response by increasing the expression of CD8+ T cells and IFN-γ+ cells while decreasing Treg cells. In general, PTPP may be a potential system for NSCLC treatment.

Potent nanoreactor-mediated ferroptosis-based strategy for the reversal of cancer chemoresistance to Sorafenib.

The drug resistance of cancer cells is related to a variety of mechanisms, among which the destruction of redox homeostasis is one of the key factors. Ferroptosis, an intracellular iron-dependent form of cell death, is related to the production of oxidative stress. The accumulation of lipid peroxidation (LPO) during ferroptosis disrupts intracellular redox homeostasis, thereby affecting the sensitivity of tumor cells to drugs. In this work, we proposed a ferroptosis strategy based on LPO accumulation, reduced glutathione generation via inhibition of SLC3A2 protein and inactivated glutathione peroxidase 4 (GPX4) to reverse the chemoresistance of cancer cells. The Fenton reaction based on the ferroptosis-inducing nanoreactors (Au/Fe-GA/Sorafenib@PEG) not only generated hydroxyl radicals (·OH) under laser irradiation to realize the accumulation of LPO, but also depleted GSH to increase the accumulation of LPO. Meanwhile, the cystine uptake of cells was inhibited by Sorafenib, resulting in reduced GSH synthesis and inactivated GPX4. In vitro and in vivo experiments demonstrated AFG/SFB@PEG + Laser group could inactivate GPX4 and the enhanced ferroptosis can reverse chemo-resistance caused by continuous upregulation of GPX4 levels in cells through 'self-rescue'. The study proposed the mechanism and feasibility of ferroptosis to reverse drug resistance, providing a promising strategy for chemo-resistant cancer treatment. STATEMENT OF SIGNIFICANCE: Herein, we proposed a ferroptosis strategy based on LPO accumulation, reduced glutathione generation via inhibition of SLC3A2 protein, and inactivated glutathione peroxidase 4 (GPX4) to reverse chemoresistance of cancer cells. The Fenton reaction based on the ferroptosis-inducing nanoreactors (Au/Fe-GA/Sorafenib@PEG) not only generated hydroxyl radicals (·OH) under laser irradiation to realize the accumulation of LPO but also depleted GSH to increase the accumulation of LPO. Meanwhile, the cystine uptake of cells was inhibited by Sorafenib, resulting in reduced GSH synthesis and inactivated GPX4. In vitro and in vivo experiments demonstrated AFG/SFB@PEG + Laser group could inactivate GPX4 and the enhanced ferroptosis can reverse chemo-resistance caused by continuous upregulation of GPX4 levels in cells through 'self-rescue'.

Enhanced antitumor effect of icariin nanoparticles coated with iRGD functionalized erythrocyte membrane.

Lung cancer is the most common cause of incidence and mortality among tumor diseases. Icariin (ICA), a potential Chinese medicine monomer, has been reported to show outstanding antitumor effects. However, the hydrophobic nature and less tumor penetration limit its potential as a topical healing agent. There are few studies report the efficacy of ICA on lung cancer, moreover, there is no biomimetic targeted delivery system in the application of ICA. Herein, we firstly develop a novel ICA bionic targeted nano-preparation, camouflaged by the tumor penetrating peptide iRGD (cRGDKGPDC), functionalized red blood cell membrane (RBCM), has the increased solubility, utilized biocompatibility, and aggravated tumor penetration of ICA. In this study, we constructed the iRGD functionalized RBCM mimetic targeted ICA-loaded nanoparticles (iRINPs) and explored the anti-tumor effect of iRINPs against lung cancer with biochemical and behavioral analysis. The results suggested that iRINPs showed improved biocompatibility and stability, and reduced phagocytic uptakes by macrophages. Besides, the modification of iRGD significantly improved the targeting ability of iRINPs. In vitro and in vivo the treatment effects and safety assays showed that iRINPs attained better therapeutic effects than ICA by inhibiting A549 cell migration, proliferation and invasion, as well as reducing side effects of ICA. Overall, we expected that the new bionic nanocarriers would be a promising nano-platform for ICA in the precise therapy of lung cancer.

Aggregation-Induced Emission Photosensitizer Synergizes Photodynamic Therapy and the Inhibition of the NF-κB Signaling Pathway to Overcome Hypoxia in Breast Cancer.

Triple-negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer, and TNBC patients often develop resistance to endocrine or molecular targeted therapy. Thus, a search for effective treatments is urgently required. Photodynamic therapy (PDT) has been verified to be a successful therapy for cancer. However, this treatment is oxygen-consuming, thus considerably limiting the PDT outcomes. The present study introduced a multistage drug delivery system to alleviate hypoxia and enhance PDT efficiency. Specifically, aggregation-induced emission luminogen (AIEgen) TPE-Py was first introduced to achieve PDT properties, and natural naphthohydroquinone dimer Rubioncolin C (RC), a blocker of mitochondria-associated oxidative phosphorylation (OXPHOS) and an NF-κB inhibitor, was applied to suppress the O2 consumption of OXPHOS and mitigate hypoxia thereafter. Enhanced PDT efficiency was validated by in vitro and in vivo TNBC models. In terms of the mechanism, AIEgen-based PDT synergized with RC could induce a fatal burst of reactive oxygen species (ROS) and ROS-mediated apoptosis. Moreover, this combination promoted the effectiveness of PDT by inhibiting the NF-κB signaling pathway. All of these results demonstrated that the administration system not only achieved a synergistic anti-TNBC effect but also expanded the clinical application of AIEgen-based PDT by overcoming hypoxia and inhibiting the NF-κB signaling pathway.

Synergistic Tumor Cytolysis by NK Cells in Combination With a Pan-HDAC Inhibitor, Panobinostat.

Histone deacetylases (HDAC) are frequently overexpressed in tumors, and their inhibition has shown promising anti-tumor effects. However, the synergistic effects of HDAC inhibition with immune cell therapy have not been fully explored. Natural killer (NK) cells are cytotoxic lymphocytes for anti-tumor immune surveillance, with immunotherapy potential. We showed that a pan-HDAC inhibitor, panobinostat, alone demonstrated anti-tumor and anti-proliferative activities on all tested tumors in vitro. Additionally, panobinostat co-treatment or pretreatment synergized with NK cells to mediate tumor cell cytolysis. Mechanistically, panobinostat treatment increased the expression of cell adhesion and tight junction-related genes, promoted conjugation formation between NK and tumor cells, and modulates NK cell-activating receptors and ligands on tumor cells, contributing to the increased tumor cytolysis. Finally, panobinostat therapy led to better tumor control and synergized with anti-PD-L1 therapy. Our data highlights the anti-tumor potential of HDAC inhibition through tumor-intrinsic toxicity and enhancement of NK -based immunotherapy.

Superior in vitro anticancer effect of biomimetic paclitaxel and triptolide co-delivery system in gastric cancer.

As a well-known anticancer drug, paclitaxel (PTX), a first-line chemotherapeutic agent, remains unsatisfactory for gastric cancer therapy. It is reported that triptolide (TPL) could enhance the anti-gastric cancer effect of PTX. Considering the poor solubility of both drugs, we developed a red blood cell membrane-biomimetic nanosystem, an emerging tool in drug delivery, to co-load paclitaxel and triptolide (red blood cell membrane coated PTX and TPL co-loaded poly(lactic-co-glycolic acid) [PLGA] nanoparticles, RP(P/T)). The successful preparation was confirmed in terms of particle size, morphology, and surface markers assays. This biomimetic system could prolong circulation and escape immune surveillance. And these properties were verified by stability, in vitro drug release, and cellular uptake assays. Moreover, the MTT and colony formation assays demonstrated the superior anti-proliferation effect of the RP(P/T) to free drugs. The enhanced antitumor effects of RP(P/T) on migration and invasion were also evaluated by wound-healing and transwell assays. Overall, the bionic co-delivery nanoplatform with improved efficacy in vitro is a promising therapy for gastric cancer.

Using Fluorescence On/Off to Trace Tandem Nanofiber Assembly/Disassembly in Living Cells.

To track an intact biological process inside cells, continuous showing of the assembly/disassembly process is needed and fluorescence is advantageous in characterizing these processes. However, using fluorescence "on/off" to observe a sequential assembly/disassembly process in living cells has not been reported. Herein, we rationally designed a probe PEA-NBD-Yp and employed its fluorescence "on/off" to trace tandem assembly/disassembly of nanofibers in living HeLa cells. In vitro experiments validated that PEA-NBD-Yp could be efficiently dephosphorylated by ALP to yield PEA-NBD-Y, which self-assembled into nanofibers with the NBD fluorescence "on". Also, the PEA-NBD-Y nanofiber was disassembled by GSH, accompanied by fluorescence "off". Living cell imaging (together with ALP-inhibition or GSH-blocking) experiments sequentially showed the self-assembling nanofibers on the cell outer membrane with fluorescence "on" (On1), translocated inside cells (On2), and disassembled by GSH with fluorescence "off" (Off2). We anticipate that our strategy of one probe conferring temporal "on/off" fluorescence signals might provide people with a new tool to deeply understand a biological event in living cells in the near future.

Exogenous oxidative stress suppresses IL-33 -driven proliferation programming in group 2 innate lymphoid cells.

Although exogenous oxidative stress has been suggested to promote the pathogenesis of airway inflammation, previous trials using conventional antioxidant therapy in asthma have been largely ineffective, suggesting the complex roles of oxidative stress in the regulation of airway inflammation and of its critical mediating lymphocyte populations. Group 2 innate lymphoid cells (ILC2s) proliferate and induce eosinophilia in response to tissue alarminsin the early phase of airway inflammation. We previously showed that IL-33 -induced endogenous reactive oxygen species is required for optimal metabolic activation of ILC2 functions, however, the role of exogenous oxidative stress in regulating ILC2 functions has not been investigated. Here, we found that exogenous oxidative stress induced by injection of ROS -generating reagent alleviated IL-33 -triggered ILC2 response and inflammation both in the airway and in the liver. Exogenous oxidative stress in ILC2s also compromised IL-33 -mediated accumulation of these cells, as well as subsequent recruitment of eosinophils, after adoptive transferring into ILC2 deficient hosts. Mechanistically, exogenous oxidative stress in ILC2s compromised the proliferation program, while preserving the expression levels of effector molecules in ILC2s. Impaired proliferation under exogenous oxidative stress led to reduced numbers of ILC2s, and an overall decrease in ILC2 response to IL-33 stimulation. Collectively, these data indicate that exogenous oxidative stress suppresses the proliferation program in ILC2s and alleviates IL-33 -triggered inflammation, suggesting that therapeutic induction of oxidative stress might alleviate ILC2 -mediated inflammation in the airway, and possibly also in other organs.

Impaired cytolytic activity of asthma-associated natural killer cells is linked to dysregulated transcriptional program in energy metabolism.

Natural killer (NK) cells are a cytotoxic subset of the innate lymphoid cells, playing essential roles in host defense against tumors and infections, which, however, are usually functionally compromised in chronic diseases. Atopic diseases, such as allergic asthma, characterized by type 2 immune responses, are usually associated with chronic inflammations. Whether asthma -associated immune environment affects the cytolytic function of NK cells has not been elucidated. Here, YTS, a human NK cell line, was exposed to serum from healthy donors or asthma patients for analysis of its cytolytic function. We found that, serum from asthma patients reduced the cytolytic activity of YTS cells against Raji human B lymphoblasts, in comparison with normal serum. The impairment of cytolytic activity of these YTS cells was accompanied with decreased degranulation potentials, weakened conjugation formation with Raji cells, and premature termination of ERK phosphorylation upon stimulation. Meanwhile, apoptosis or cell death of YTS cells was not increased after exposure to serum from asthma patients. Importantly, such impairment of cytolytic activity of asthma -associated YTS NK cells was accompanied with aberrantly enriched genes involved in oxidative phosphorylation. Taken together, these results demonstrate that the serum of asthma patients directly suppresses the cytolytic function of NK cells, possibly through dysregulation of energy metabolism in NK cells.