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74 result(s) for "Kwon, Ick Chan"
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Combined Rho-kinase inhibition and immunogenic cell death triggers and propagates immunity against cancer
Activation of T cell immune response is critical for the therapeutic efficacy of cancer immunotherapy. Current immunotherapies have shown remarkable clinical success against several cancers; however, significant responses remain restricted to a minority of patients. Here, we show a therapeutic strategy that combines enhancing the phagocytic activity of antigen-presenting cells with immunogenic cell death to trigger efficient antitumour immunity. Rho-kinase (ROCK) blockade increases cancer cell phagocytosis and induces antitumour immunity through enhancement of T cell priming by dendritic cells (DCs), leading to suppression of tumour growth in syngeneic tumour models. Combining ROCK blockade with immunogenic chemotherapy leads to increased DC maturation and synergistic CD8 + cytotoxic T cell priming and infiltration into tumours. This therapeutic strategy effectively suppresses tumour growth and improves overall survival in a genetic mouse mammary tumour virus/Neu tumour model. Collectively, these results suggest that boosting intrinsic cancer immunity using immunogenic killing and enhanced phagocytosis is a promising therapeutic strategy for cancer immunotherapy. Activation of an immune response is critical for the efficacy of cancer therapies. Here, the authors show that combination of ROCK inhibitor with chemotherapeutics that induce immunogenic cell death of cancer cells leads to increased dendritic cells’ maturation and synergistic CD8 + cytotoxic T cell priming and infiltration into the tumours, leading to suppressed tumour growth and improved overall survival in syngeneic and genetically engineered tumour models.
Alliance with EPR Effect: Combined Strategies to Improve the EPR Effect in the Tumor Microenvironment
The use of nanomedicine for cancer treatment takes advantage of its preferential accumulation in tumors owing to the enhanced permeability and retention (EPR) effect. The development of cancer nanomedicine has promised highly effective treatment options unprecedented by standard therapeutics. However, the therapeutic efficacy of passively targeted nanomedicine is not always satisfactory because it is largely influenced by the heterogeneity of the intensity of the EPR effect exhibited within a tumor, at different stages of a tumor, and among individual tumors. In addition, limited data on EPR effectiveness in human hinders further clinical translation of nanomedicine. This unsatisfactory therapeutic outcome in mice and humans necessitates novel approaches to improve the EPR effect. This review focuses on current attempts at overcoming the limitations of traditional EPR-dependent nanomedicine by incorporating supplementary strategies, such as additional molecular targeting, physical alteration, or physiological remodeling of the tumor microenvironment. This review will provide valuable insight to researchers who seek to overcome the limitations of relying on the EPR effect alone in cancer nanomedicine and go \"beyond the EPR effect\".
Doxorubicin Loaded pH-sensitive Micelle: Antitumoral Efficacy against Ovarian A2780/DOXR Tumor
Purpose To evaluate pH-sensitive mixed micelles for multidrug resistant (MDR) ovarian tumor targeting and optical imaging of solid tumors. Method Doxorubicin (DOX) encapsulated pH-sensitive mixed micelles composed of poly( l -histidine)(MW 5K)- b -PEG(MW 2K) and poly( l -lactic acid)(3K)- b -PEG (2K)-folate (PHSM-f) were prepared. Folate receptor-mediated endocytosis, drug uptake, endosomal disruption and cell viability were investigated at the cellular level. For in vivo tumor growth inhibition tests, multidrug resistant ovarian A2780/DOX R xenografted nude mice were used. Optical imaging was performed by using a Cy5.5 fluorescence dye-labeled mixed micelle system. Cy5.5 fluorescence intensity at the tumor site was measured in KB epidermoid xenografted nude mice. Results In vitro cell viability and drug distribution in the cytoplasm demonstrated the significantly superior efficacy of PHSM-f to free DOX and a control sample of DOX loaded pH-insensitive micelle composed of poly( l -lactic acid)(3K)- b -PEG(2K)/poly( l -lactic acid)(3K)- b -PEG(2K)-folate (80/20 wt/wt%) (PHIM-f). The mechanisms of these results were proved by folate receptor mediated endocytosis of micelle and endosomal disruption function by it. In addition, the optical imaging demonstrated the future application of the diagnositic area. PHSM-f inhibited the growth of multidrug resistant ovarian tumors efficiently in mice, with minimum weight loss. Conclusions The pH-sensitive mixed micelle system demonstrates effective antitumor efficacy against the multidrug resistant ovarian tumor A2780/DOX R .
Exosome‐Guided Phenotypic Switch of M1 to M2 Macrophages for Cutaneous Wound Healing
Macrophages (Mϕs) critically contribute to wound healing by coordinating inflammatory, proliferative, and angiogenic processes. A proper switch from proinflammatory M1 to anti‐inflammatory M2 dominant Mϕs accelerates the wound healing processes leading to favorable wound‐care outcomes. Herein, an exosome‐guided cell reprogramming technique is proposed to directly convert M1 to M2 Mϕs for effective wound management. The M2 Mϕ‐derived exosomes (M2‐Exo) induce a complete conversion of M1 to M2 Mϕs in vitro. The reprogrammed M2 Mϕs turn Arginase (M2‐marker) and iNOS (M1‐marker) on and off, respectively, and exhibit distinct phenotypic and functional features of M2 Mϕs. M2‐Exo has not only Mϕ reprogramming factors but also various cytokines and growth factors promoting wound repair. After subcutaneous administration of M2‐Exo into the wound edge, the local populations of M1 and M2 Mϕs are markedly decreased and increased, respectively, showing a successful exosome‐guided switch to M2 Mϕ polarization. The direct conversion of M1 to M2 Mϕs at the wound site accelerates wound healing by enhancing angiogenesis, re‐epithelialization, and collagen deposition. The Mϕ phenotype switching induced by exosomes possessing the excellent cell reprogramming capability and innate biocompatibility can be a promising therapeutic approach for various inflammation‐associated disorders by regulating the balance between pro‐ versus anti‐inflammatory Mϕs. An exosome‐guided cell reprogramming technique to directly convert M1 to M2 macrophages in situ is introduced as a promising therapeutic strategy for effective and rapid wound healing. With excellent cell reprogramming capabilities and biocompatibility, the exosome‐guided macrophage reprogramming technique can be applied not only to wound healing but also to various inflammation related diseases.
Phage display selection of peptides that home to atherosclerotic plaques: IL‐4 receptor as a candidate target in atherosclerosis
Imaging or drug delivery tools for atherosclerosis based on the plaque biology are still insufficient. Here, we attempted to identify peptides that selectively home to atherosclerotic plaques using phage display. A phage library containing random peptides was ex viv screened for binding to human atheroma tissues. After three to four rounds of selection, the DNA inserts of phage clones wer sequenced. A peptide sequence, CRKRLDRNC, was the most frequently occurring one. Intravenously injected phage displaying the CRKRLDRNC peptide was observed to home to atherosclerotic aortic tissues of low‐density lipoprotein receptor‐deficient (Ldlr−/–) mice at higher levels than to normal aortic tissues of wild‐type mice. Moreover, a fluorescein‐ or radioisotope‐conjugated synthetic CRKRLDRNC peptide, but not a control peptide, homed in vivo to atherosclerotic plaques in Ldlr−/– mice, while homing of the peptide to other organs such as brain was minimal. The homing peptide co‐localized with endothelial cells, macrophages and smooth muscle cells a mouse and human atherosclerotic plaques. Homology search revealed that the CRKRLDRNC peptide shares a motif of interleukin‐receptor (IL‐4) that is critical for binding to its receptor. The peptide indeed co‐localized with IL‐4 receptor (IL‐4R) at atherosclerotic plaques. Moreover, the peptide bound to cultured cells expressing IL‐4R on the cell surface and the binding was inhibited by the knock‐down of IL‐4R. These results show that the CRKRLDRNC peptide homes to atherosclerotic plaques through binding to IL‐4R as its target and may be a useful tool for selective drug delivery and molecular imaging of atherosclerosis.
Discovery of a phosphatidylserine‐recognizing peptide and its utility in molecular imaging of tumour apoptosis
The exposure of phosphatidylserine (PS) molecules from the inner to the outer leaflet of the plasma membrane has been recognized as a well‐defined molecular epitope of cells undergoing apoptosis. Examination and monitoring of PS exposure is an extensively used molecular marker in non‐invasive apoptosis imaging under a variety of clinical conditions, including the assessment of therapeutic anti‐cancer agents and myocardial infarction. Herein, we report the identification of a PS‐recognizing peptide which was identified by the screening of an M13 phage display peptide library onto PS‐coated ELISA plates. Repeated biopanning for a total of four rounds revealed a predominant enrichment of the phage clone displaying peptide sequence, CLSYYPSYC (46%). The identified phage clone evidenced enhanced binding to a number of apoptotic cells over non‐apoptotic cells, and this binding was inhibited by both annexin V and synthesized peptide displayed on the phage. The binding of the fluorescein‐labelled CLSYYPSYC peptide to apoptotic versus normal cells was assessed by both FACS analysis and fluorescence microscopy. Optical imaging after the systemic administration of fluorescein‐labelled CLSYYPSYC peptide to tumour‐bearing nude mice (H460 cells xenograft model) treated with a single dose of an anticancer drug (camp‐tothecin) indicated peptide homing to the tumour. The histological examination of tumour tissues showed intense staining of the tumour vasculature and apoptotic tumour cells. With these results, the CLSYYPSYC peptide is recognized as a novel PS‐recognizing moiety which may possibly be developed into a molecular probe for the imaging of apoptosis in vivo. This application would clearly be relevant to assessments of the efficacy of anticancer therapy in tumours.
ROS-generating TiO2 nanoparticles for non-invasive sonodynamic therapy of cancer
The non-invasive photodynamic therapy has been limited to treat superficial tumours, primarily ascribed to poor tissue penetration of light as the energy source. Herein, we designed a long-circulating hydrophilized titanium dioxide nanoparticle (HTiO 2 NP) that can be activated by ultrasound to generate reactive oxygen species (ROS). When administered systemically to mice, HTiO 2 NPs effectively suppressed the growth of superficial tumours after ultrasound treatments. In tumour tissue, the levels of proinflammatory cytokines were elevated several fold and intense vascular damage was observed. Notably, ultrasound treatments with HTiO 2 NPs also suppressed the growth of deeply located liver tumours at least 15-fold, compared to animals without ultrasound treatments. This study provides the first demonstration of the feasibility of using HTiO 2 NPs as sensitizers for sonodynamic therapy in vivo .
Development of Biocompatible HA Hydrogels Embedded with a New Synthetic Peptide Promoting Cellular Migration for Advanced Wound Care Management
In the past few years, there have been many efforts underway to develop effective wound healing treatments for traumatic injuries. In particular, wound‐healing peptides (WHPs) and peptide‐grafted dressings hold great promise for novel therapeutic strategies for wound management. This study reports a topical formulation of a new synthetic WHP (REGRT, REG) embedded in a hyaluronic acid (HA)‐based hydrogel dressing for the enhancement of acute excisional wound repair. The copper‐free click chemistry is utilized to form biocompatible HA hydrogels by cross‐linking dibenzocyclooctyl‐functionalized HA with 4‐arm poly(ethylene glycol) (PEG) azide. The HA hydrogels are grafted with the REG peptide, a functional derivative of erythroid differentiation regulator1, displaying potent cell motility‐stimulating ability, thus sustainably releasing physiologically active peptides for a prolonged period. Combined with the traditional wound healing benefits of HA, the HA hydrogel embedded REG (REG‐HAgel) accelerates re‐epithelialization in skin wound healing, particularly by promoting migration of fibroblasts, keratinocytes, and endothelial cells. REG‐HAgels improve not only rate, but quality of wound healing with higher collagen deposition and more microvascular formation while being nontoxic. The peptide‐grafted HA hydrogel system can be considered as a promising new wound dressing formulation strategy for the treatment of different types of wounds with combinations of various natural and synthetic WHPs. A novel synthetic wound healing peptide (REGRT)‐grafted biocompatible hyaluronic acid hydrogel (HAgel) is introduced as a potential wound care strategy for the enhancement of acute excisional wound repair. As an advanced wound dressing platform, the bioactive REGRT and the HAgels cross‐linked via copper‐free click chemistry can have a synergistic effect in wound management.
Statin-dye conjugates for selective targeting of KRAS mutant cancer cells
Over 90% of pancreatic ductal adenocarcinoma (PDAC) patients involve KRAS mutations ( KRAS MUT ), for which current treatment options are limited. Statins, commonly used to lower cholesterol, have demonstrated certain selective toxicity towards KRAS -transformed cells, prompting the question of whether statin-based conjugates could achieve selective uptake specifically in KRAS MUT cells. To investigate this, we synthesized statin-dye conjugates by attaching a fluorescent dye (Cy5.5) to two statins: simvastatin and pravastatin, aiming to assess whether selective uptake indeed occurs. Our findings revealed that these conjugates exhibited markedly enhanced uptake in KRAS MUT cells compared to KRAS wild-type ( KRAS WT ) cells. We evaluated the uptake of these conjugates in both KRAS MUT and KRAS WT cells and examined their potential to selectively target KRAS MUT pancreatic cancer cells (PCCs) using an engineered PDAC tumor model co-cultured with PCCs and cancer-associated fibroblasts (CAFs). Our findings indicate that KRAS MUT cancer cells exhibited higher uptake of statin-Cy5.5 conjugates via enhanced macropinocytosis compared to KRAS WT cancer cells and CAFs. We also found enhanced uptake of the statin-Cy5.5 conjugate in MCF10A cells with PTEN deficiency, a condition known to elevate macropinocytosis, compared to control MCF10A cells with wild-type PTEN . Notably, in the PCC and CAF co-culture model, the pravastatin-Cy5.5 conjugate selectively killed KRAS MUT PCCs without affecting the KRAS WT CAFs. These findings highlight the unique synergistic potential of statin-Cy5.5—distinct from either component alone—as targeted delivery vehicles for KRAS MUT cancer therapy.
Caspase-3/-7-Specific Metabolic Precursor for Bioorthogonal Tracking of Tumor Apoptosis
Apoptosis is one of the most important intracellular events in living cell, which is a programmed cell death interrelated with caspase enzyme activity for maintaining homeostasis in multicellular organisms. Therefore, direct apoptosis imaging of living cells can provide enormous advantages for diagnosis, drug discovery, and therapeutic monitoring in various diseases. However, a method of direct apoptosis imaging has not been fully validated, especially for live cells in in vitro and in vivo . Herein, we developed a new apoptosis imaging technology via a direct visualization of active caspase-3/-7 activity in living cells. For this, we synthesized a caspase-3/-7-specific cleavable peptide (KGDEVD) conjugated triacetylated N-azidoacetyl-D-mannosamine (Apo-S-Ac 3 ManNAz), wherein the Apo-S-Ac 3 ManNAz can be cleaved by the active caspase-3/-7 in live apoptotic cells and the cleaved Ac 3 ManNAz molecules can further generate targetable azido groups (N 3 ) on the living cell surface. Importantly, the azido groups on the apoptotic tumor cells could be visualized with Cy5.5-conjugated dibenzylcyclooctyne (DBCO-Cy5.5) via bioorthogonal click chemistry in vitro cell culture condition and in vivo tumor-bearing mice. Therefore, our Apo-S-Ac 3 ManNAz can be utilized for the further applications in tumor therapy as a monitoring tool for anticancer efficacy and optimization of anticancer new drugs in cell culture system and in tumor-bearing mice.