Inside Tumor Research Articles

Application of Multi-Omics Approach in Sarcomas: A Tool for Studying Mechanism, Biomarkers, and Therapeutic Targets.

Sarcomas are rare, heterogeneous mesenchymal neoplasms with various subtypes, each exhibiting unique genetic characteristics. Although studies have been conducted to improve the treatment for sarcomas, the specific development from normal somatic cells to sarcoma cells is still unclear and needs further research. The diagnosis of sarcomas depends heavily on the pathological examination, which is yet a difficult work and requires expert analysis. Advanced treatment like precise medicine optimizes the efficacy of treatment and the prognosis of sarcoma patients, yet, in sarcomas, more studies should be done to put such methods in clinical practice. The revolution of advanced technology has pushed the multi-omics approach to the front, and more could be learnt in sarcomas with such methods. Multi-omics combines the character of each omics techniques, analyzes the mechanism of tumor cells from different levels, which makes up for the shortage of single-omics, and gives us an integrated picture of bioactivities inside tumor cells. Multi-omics research of sarcomas has reached appreciable progress in recent years, leading to a better understanding of the mutation, proliferation, and metastasis of sarcomas. With the help of multi-omics approach, novel biomarkers were found, with promising effects in improving the process of diagnosis, prognosis anticipation, and treatment decision. By analyzing large amounts of biological features, subtype clustering could be done in a better precision, which may be useful in the clinical procedure. In this review, we summarized recent discoveries using multi-omics approach in sarcomas, discussed their merits and challenges, and concluded with future perspectives of the sarcoma research.

Lactate-driving Pt nanoflower with positive chemotaxis for deep intratumoral penetration

The deep penetration in response to specific intratumoral conditions holds considerable potential in achieving a more effective therapy. Lactate is mainly produced by exuberant-metabolism tumor cells growing in the deep center of solid tumor, which would form the characteristic of higher-level lactate deep inside tumor in distance with blood vessels. Herein, inspired by the in vitro directional chemotaxis of enzyme-powered nanomotor driven by substrate gradient, a novel lactate oxidase (LOX)-powered Pt Nanoflowers (Pt NFs) was developed to achieve deep intratumoral penetration triggered by the lactate-driving positive chemotaxis that was confirmed both in vitro and in vivo for the first time. Besides, LOX-powered Pt NFs with self-oxygenation could achieve a more thorough effect on hypoxic relief via the cascading catalysis: (1) the orthotopic extra H2O2 production from lactate catalyzed by LOX, and (2) the effective conversion of both extra-supplement and endogenous H2O2 into O2 catalyzed by Pt NFs, further overcoming the hypoxia-induced radioresistance. Meanwhile, the X-ray radiation deposited inside Pt NFs could improve low-dose radiotherapy effect with increasing ROS level and enhancing nuclear DNA damage. Collectively, this work would provide a blueprint for developing substrate gradient-driving "smart" delivery systems and radiosensitization strategy.

Characterization of the Immunological Status of Hypermutated Solid Tumors in the Cancer Genome Analysis Project HOPE.

Many reports demonstrate that a high tumor mutation burden (TMB-H) is closely associated with good prognosis of cancer. However, specific studies investigating the association of various TMB statuses with overall survival in patients with solid tumors are scarce. In the present study, we investigated the association of TMB status with overall survival in 5,072 patients with cancer from the HOPE project and clarified the specific mechanism responsible for the good prognosis of the TMB-H group. All tumors were classified into one of four groups based on TMB: ultralow (UL), low (L), intermediate (I) and high (H). The TMB-H group had a better prognosis than the TMB-I and TMB-L groups, but not than the TMB-UL group. Analyzing the expression of 293 immune response-associated genes, 17 genes were up-regulated in the TMB-H group compared to the TMB-I and TNB-L groups, and two genes [CD274 and interferon-γ (IFNG)] were identified as good prognostic factors. Analysis of immune cell populations inside tumors demonstrated that the frequencies of exhausted CD8+ T-cells, activated effector CD8+ T-cells and natural killer cells were significantly higher in the TMB-H group. The T-cell receptor repertoire numbers and the diversity evenness score (DE50) were lower in the TMB-H group than in TMB-UL group; however, no association of the DE50 value with the binding or elution affinity of epitope peptides from neoantigens was found. One possible mechanism for the good prognosis of the TMB-UL group compared to the TMB-H group might be that the TMB-UL group features a balance between immunosuppression and immunostimulation.

Abstract 6349A: Mechanical stress activates autophagy to induce drug resistance in pancreatic cancer cells

Abstract INTRODUCTION: One of the most fundamental problems that oncologists are currently facing in pancreatic cancer patient care is the high resistance to all types of chemotherapies or targeted therapies. Thus, there is an urgent need for increasing patient response to treatment. A common characteristic among most pancreatic cancer patients that could serve as potential target for treatment, is the biomechanically abnormal tumor microenvironment (TME). This altered TME is characterized by an increased stiffness which among others, is responsible for the development of mechanical stresses in the tumor interior. Even though several studies have investigated the effect of mechanical stress on cancer cells and tumor progression, it has not yet defined whether it can affect drug sensitivity and what are the mechanisms involved. HYPOTHESIS: Based on our recent findings, obtained by a Reverse Phase Protein Assay, we observed that mechanical stress activates a resistance response, employing autophagy activation, in pancreatic cancer cells. To this end, we hypothesize that mechanical stress developed during tumor growth, can induce autophagy activation to eventually promote drug resistance in pancreatic tumors. Therefore, inhibition of this mechanism can improve therapy. METHODOLOGY: We use two pancreatic cancer cells lines, MIA PaCa-2 and PANC-1, to apply mechanical stress, either in a 2D experimental setup or by employing tumor spheroids in a 3D agarose matrix. In both cases, cells are exposed to the most common chemotherapeutic agents used for pancreatic cancer treatment, gemcitabine and 5-Fluorouracil (5FU). The cytotoxic effect of each drug, as well as autophagy- and signaling pathway- activation are then analyzed. Finally, in vitro assays and treatments, along with in vivo animal models of pancreatic tumors, are performed to test the efficacy of an autophagy inhibitor combined with chemotherapy and a mechanotherapeutic that modulates intratumoral mechanical stresses. RESULTS: Proteomic analysis, together with pharmacological inhibition and siRNA treatments, revealed that mechanical stress activates autophagy to impair cell apoptosis and promote cancer cell survival. This stress-adaptation mechanism in turn impairs the cytotoxic effect of both gemcitabine and 5FU. A combined treatment employing chemotherapy with an autophagy inhibitor, and a mechanotherapeutic agent, showed promising results in increasing the overall-survival of pancreatic tumor-bearing mice. CONCLUSION: Our results provide solid evidence that alleviation of intratumoral mechanical stresses with mechanotherapeutics combined with autophagy inhibitors can improve the efficacy of chemotherapeutic agents in pancreatic cancer. Citation Format: Maria Kalli, Ruxuan Li, Ioannis Zervantonakis, Triantafyllos Stylianopoulos. Mechanical stress activates autophagy to induce drug resistance in pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6349A.

Current Status and Future Directions of Bacteria-Based Immunotherapy.

With the in-depth understanding of the anti-cancer immunity, immunotherapy has become a promising cancer treatment after surgery, radiotherapy, and chemotherapy. As natural immunogenicity substances, some bacteria can preferentially colonize and proliferate inside tumor tissues to interact with the host and exert anti-tumor effect. However, further research is hampered by the infection-associated toxicity and their unpredictable behaviors in vivo. Due to modern advances in genetic engineering, synthetic biology, and material science, modifying bacteria to minimize the toxicity and constructing a bacteria-based immunotherapy platform has become a hotspot in recent research. This review will cover the inherent advantages of unedited bacteria, highlight how bacteria can be engineered to provide greater tumor-targeting properties, enhanced immune-modulation effect, and improved safety. Successful applications of engineered bacteria in cancer immunotherapy or as part of the combination therapy are discussed as well as the bacteria based immunotherapy in different cancer types. In the end, we highlight the future directions and potential opportunities of this emerging field.

Putative pathways fueling anaerobic mitochondrial respiration

Tumor interiors undergo prolonged anoxia; however, the pathways involved have not been identified. Since NO and H2S function in prokaryotic anaerobic respiration, the effect their pathway elements have on HeLa 229 cell viability was measured after 10 days anaerobic incubation. Arginine or xanthine (NO pathway precursors) increased cell viability (13.1- and 4.4-fold, respectively). The H2S pathway precursor, cysteine, also enhanced viability (9.8-fold), as did H2S donor GYY4137, or inhibitor of glutathione synthesis, propargylglycine, (40- and 85-fold, respectively). These results demonstrate that cell viability after extended anaerobic incubation (10 days) can be modulated by affecting NO or H2S pathways.

Targeted delivery and enhanced uptake of chemo-photodynamic nanomedicine for melanoma treatment

Nanoparticles (NPs) modified with targeting ligands have often shown great potential in targeted drug delivery for tumor therapy. However, the clearance of NPs by the monocyte-phagocyte system (MPS) and the relatively low cellular uptake by tumor cells have significantly limited the antitumor efficacy of a variety of nanomedicines. Tumor microenvironment-mediated multidrug resistance also reduces the antitumor efficacy of internalized nanomedicines. Herein, we developed an innovative nanomedicine for combined chemo-photodynamic therapy of melanoma through targeted drug delivery and significantly improved the cellular uptake of the nanomedicine through the charge-reversal phenomenon. An amphiphilic platinum (IV)-polyethylenimine-chlorin e6 (Pt(IV)-PEI-Ce6) polymer was designed, prepared, and self-assembled into NPs (PPC) in an aqueous solution, and these NPs were subsequently coated with hyaluronic acid (HA) to afford PPC@HA. The surface-coated HA provided PPC with a negatively charged surface potential to reduce the clearance by the MPS during systemic circulation and enhanced the targeted delivery of PPC to CD44-overexpressing melanoma cells. Upon accumulation in the tumor site, hyaluronidase overexpressed in the tumor induced HA degradation to release the positively charged PPC, resulting in an increased internalization of PPC into tumor cells. Bioactive Pt(II) was released in response to high glutathione level in the tumor cells for effective tumor chemotherapy. Under 650 nm laser irradiation, Ce6 produced reactive oxygen species (ROS), thus driving photodynamic therapy. Finally, PPC@HA exhibited combined photodynamic-chemotherapeutic antitumor efficacy against the melanoma cells in mice. Statement of significanceTumors are one of the greatest threats to human health, and chemotherapy has been one of the most common therapeutic modalities for treating tumors; however, many challenges related to chemotherapy remain, such as low delivery efficiency, side effects, and unsatisfactory therapeutic efficacy. Nanomedicines modified with targeting ligands have often shown great potential in improving targeted drug delivery for tumor therapy; however, the clearance of nanomaterials by the monocyte-phagocyte system and the relatively low cellular uptake by tumor cells have significantly limited the antitumor efficacy of a variety of nanomedicines. Herein, we developed a novel charge-reversal-based, hyaluronic acid-coated, Pt(IV) prodrug and chlorin e6-based nanomedicine to improve systemic circulation and targeted accumulation of the nanomedicine in the tumor tissue and to enhance its intracellular uptake. This nanomedicine may provide a potential new platform to improve the drug content inside tumor cells and to effectively inhibit tumor growth through combined chemotherapy and photodynamic therapy.

ROS-Responsive Selenopolypeptide Micelles: Preparation, Characterization, and Controlled Drug Release.

Sulfur-containing polypeptides, capable of reactive oxygen species (ROS)-responsive structural change, are one of the most important building blocks for the construction of polypeptide-based drug delivery systems. However, the relatively low ROS sensitivity of side-chain thioethers limits the biomedical applications of these polypeptides because they usually require a high concentration of ROS beyond the pathological ROS level in the tumor microenvironment. Herein, we report the design and synthesis of a selenium-containing polypeptide, which undergoes random coil-to-extended helix and hydrophobic-to-hydrophilic transitions in the presence of 0.1% H2O2, a concentration that is much lower than the ROS requirement for thioether. ROS-responsive micelles were thus prepared from the amphiphilic copolymer consisting of the hydrophilic poly(ethylene glycol) (PEG) segment and hydrophobic selenopolypeptide segment and were used to encapsulate doxorubicin (DOX). The micelles could be sensitively dissociated inside tumor cells in consequence of ROS-triggered oxidation of side-chain selenoether and structural change of the micelles, thereby efficiently and selectively releasing the encapsulated DOX to kill cancer cells. This work provides an alternative design of ROS-responsive polypeptides with higher sensitivity than that of the existing sulfur-containing polypeptides, which may expand the biomedical applications of polypeptide materials.

Synergizing effects of chemodynamic therapy and chemotherapy against breast cancer by oxaliplatin-loaded polydopamine/BSA@copper ferrite

Chemodynamic therapy (CDT) is defined as the generation of abundant ROS inside tumor tissue by a Fenton reaction-based nanocatalyst, which is characterized by high selectivity and few side effects. However, the rate of ROS generation by Fenton reaction is limited due to a scarcity of Fenton-based catalysts within cells and a high level of intracellular antioxidant agents. In this study, a heterogeneous Fenton nanocatalyst, copper ferrite nanoparticles (CuFe2O4), was synthesized and it was accompanied by oxaliplatin (Oxa), a ROS-producing chemotherapeutic drug. CuFe2O4 was synthesized through the hydrothermal method and bovine serum albumin was used as a biological capping agent. The nanoparticles possessed a high surface area and mesoporous structure with an extremely small particle size of about 6.1 nm. Nanoparticles had a high capacity for oxaliplatin (3.4 mg g−1) and were then modified in situ by polydopamine (PDA) via alkaline-triggered polymerization, resulting in a pH-sensitive drug delivery system. The final construct (CuFe2O4.Oxa@PDA) showed pH-responsive drug release in a time-staggered manner. In vitro studies disclosed that CuFe2O4.Oxa@PDA nanoparticles were internalized by breast cancer cells (4T1), inhibiting tumor cell growth more effectively than free oxaliplatin. Furthermore, less cytotoxicity was observed against normal cells (NIH3T3), indicating that the construct's cytotoxic effects are directed solely at tumor cells. Furthermore, CuFe2O4.Oxa@PDA effectively catalyzed the Fenton reaction inside tumor cells, allowing it to amplify intracellular oxidative stress by lowering intracellular GSH levels and inhibiting catalase activity. Based on these findings, CuFe2O4.Oxa@PDA could be used as an adjuvant nanoparticle along with oxaliplatin-based cancer chemotherapy, significantly reinforcing intratumoral oxidative stress and promoting the clinical efficacy of oxaliplatin.

Size-changeable nanoprobes for the combined radiotherapy and photodynamic therapy of tumor

Radiation therapy (RT) and photodynamic therapy (PDT) are promising while challenging in treating tumors. The potential radiation resistance of tumor cells and side effects to healthy tissues restrict their clinical treatment efficacy. Effective delivery of therapeutic agents to the deep tumor tissues would be available for tumor-accurate therapy and promising for the tumor therapy. Thus, developing nanoprobes with effectively delivering radiotherapy sensitizers and photosensitizers to the interior of tumors is needed for the accurate combined RT and PDT of tumor. The size-changeable nanoprobes of Gd2O3@BSA-BSA-Ce6 (BGBC) were synthesized with a crosslinking method. Magnetic resonance imaging (MRI) and in vivo near-infrared (NIR) imaging were measured to evaluate the nanoprobes' tumor accumulation and intratumor penetration effect. The tumor suppression effect of combined RT and PDT with these nanoprobes was also studied for the 4T1 bearing Balb/c mice. The nanoprobes BGBC showed high tumor accumulation and disintegrated into small particles responding to the photo-irradiation-produced reactive oxygen species (ROS), allowing for tumor penetration. Abundant radiotherapy sensitizers and photosensitizers were delivered to the deep tumor tissues, which is available for the accurate therapy of tumor. In addition, the BGBC displayed outstanding MRI and fluorescence imaging effects for evaluating the biodistribution and tumor suppression effect of nanoprobes. Consequently, significant tumor suppression effect was obtained based on the accurate tumor treatment with the combined RT and PDT. The designed size-changeable nanoprobes BGBC showed excellent tumor accumulation and deep tumor penetration, resulting in a significant tumor suppression effect based on the combined RT and PDT. This study provides a novel strategy for dual delivery of radiotherapy sensitizers and photosensitizers into the deep tumor tissues and is promising for the accurate theranostics of tumor.

Incorporating vascular-stasis based blood perfusion to evaluate the thermal signatures of cell-death using modified Arrhenius equation with regeneration of living tissues during nanoparticle-assisted thermal therapy

Cellular and biological tissue heating may result in reversible (or repairable injury) and irreversible (or lethal) thermal cell-death in living biological tissues. Continuous regeneration of living human tissues due to the continuous supply of oxygen through arterial blood must be taken into account to counter balance the thermal degradation at quasi-static thermal conditions. This study incorporates vascular-stasis based non-linear blood perfusion for magnetic nanoparticle assisted thermal therapy to model the thermal by-stander effect - a hyperthermia-induced deep infiltration of nanoparticles in the targeted tissue domain. Pennes bioheat model based on Fourier heat conduction theory is four-way coupled with Arrhenius and non-Arrhenius kinetic models of cell-death with healthy cells regeneration. In determination of treatment endpoint, the kinetic model must be coupled with quantitative and qualitative pathological biomarkers of thermal damage. Nanoparticle distribution volume increases by 39.62% after possible rupturing of cell membrane during heating. The release of intracellular solution by dead cells during heating promotes nanoparticle migration from the region of higher concentration to the regions of lower concentration thereby 80% enhancement in interstitial space and five-fold increase in diffusion coefficient. For such redistribution phenomenon, the heating time is sufficient to reduce the oxygen in erythrocytes (red blood cells) and maximize the necrosis zone inside tumour. However, at the interface, the regeneration of healthy cells triggers an immune response of biological tissue towards continued heating to suppress, prevent and restrict further accumulation of thermal damage within damage bounds of Ω ≤ 1. While modelling the kinetics of thermal damage of tumour, one must include and should not ignore the partial self-regeneration of connecting normal human tissues at the tumour periphery due to continuous matching of oxygen demands in the healthy tissue by the arterial blood.

Novel low-avidity glypican-3 specific CARTs resist exhaustion and mediate durable antitumor effects against hepatocellular carcinoma

Abstract Background & Aims Chimeric antigen receptor engineered T cells (CARTs) for hepatocellular carcinoma (HCC) and other solid tumors are not as effective as they are for blood cancers. CARTs may lose function inside tumors due to persistent antigen engagement. The aims of this study are to develop low-affinity monoclonal antibodies (mAb) and low-avidity CARTs for HCC and to test the hypothesis that low-avidity CARTs can resist exhaustion and maintain functions in solid tumors, generating durable antitumor effects. Methods and results New human glypican-3 (hGPC3) mAbs were developed from immunized mice. We obtained 3 hGPC3-specific mAbs that stained HCC tumors, but not the adjacent normal liver tissues. One of them, 8F8, bound an epitope close to that of GC33, the frequently used high-affinity mAb, but with ~17 fold lower affinity. We then compared the 8F8 CARTs to GC33 CARTs for their in vitro function and in vivo antitumor effects. In vitro, low-avidity 8F8 CARTs killed both hGPC3high and hGPC3low HCC tumor cells to the same extent as high-avidity GC33 CARTs. 8F8 CARTs expanded and persisted to a greater extent than GC33 CARTs, resulting in durable responses against HCC xenografts. Importantly, compared to GC33 CARTs, there were 5 folds more of 8F8-BBz CARTs in the tumor mass for a longer period of time. Remarkably, the tumor infiltrating 8F8 CARTs were less exhausted and apoptotic, and more functional than GC33 CARTs. Conclusion The novel low-avidity 8F8-BBz CART resists exhaustion and apoptosis inside tumor lesions, demonstrating a greater therapeutic potential than high-avidity CARTs.

O-17 - Preclinical assessment of nanoparticles conjugated with 64Cu-DOTA-PEG-BBN targeting gastrin-releasing peptide receptors

1508 Objectives: Gold andiron oxide based nanoparticleshave emerged as innovative tools for cancer imaging and therapy, as benefit of their size, biocompatibility and pharmacokinetics. Their surface functionalization with high number of recognizable biomolecules (gastrin-releasing peptides, GRP, namely bombesin, BBN, bombesin-like short chain peptide, BBN(7-14), and Neuromedin B, NMB) forms high-specific targeted systems, suitable for multimodal PET-MRI or PET-CT imaging aimed for early detection of tumours and/or therapy monitoring and follow-up. The aim of this study was to investigate preclinically and comparatively evaluate the potential as imaging agents of activated N-Hydroxysuccinimide gold nanoparticles, coated with polyethylene glycol (PEG) and conjugated to 64Cu-DOTA-BBN/BBN(7-14)/NMB and iron oxide nanoparticles coated with PEG and conjugated to 68Ga-DOTA-BBN/BBN(7-14)/NMB, respectively. Methods: The morphology and size distribution of gold/iron oxide nanoparticles were examined by TEM/SEM coupled with energy dispersion spectroscopy (EDS) techniques and, after functionalization, by UV-Vis spectroscopy and DLS. The gold/iron oxide NPs were fconjugated to PEG(4)-BBN(7-14), PEG(4)-BBN, and PEG(4)-NeuromedinB, previously radiolabelled with Cu-64 using DOTA as chelating agent. The radiolabelled nanoconjugates were incubated with neuroendocrine colorectal cancer cells HT-29 and HCT116, and prostate cancer cells DU-145, all over-expressing GRPRs. We investigated the specific binding of Bombesin (BBN), Bombesin-like peptide sequence BBN(7-14) and Neuromedin B (NMB) to GRP receptors in the presence of cold competitor antagonist ligands. In-vivo PET imaging was performed on high-resolution micro-PET-CT system, on tumor bearing nude mice (Nu/J) inoculated with HT-29, HCT116 and DU-145 tumors, respectively. Results: In vitro binding kinetics assessment showed an increased retention of over 30% of radioisotope inside tumor cells in the case of AuNP-PEG(4)-64Cu-DOTA-BBN(7-14), compared to 64Cu-DOTA-PEG(4)-BBN(7-14) alone. Similarly, IONP-PEG(4)-64Cu-DOTA-NMB was better uptaken and internalized, compared to 64Cu-DOTA-PEG(4)-NMB alone. These results are attributed to the increased concentration and multiple binding sites of BBN-like peptides to GRPRs allowed by their exposure on the surface of NPs. Subsequently, higher internalization rate is promoted, by receptor-mediated endocytosis. Biodistribution/imaging studies, and the results show high and stable tumor uptake of the radiolabelled nanoconjugates, fast blood-clearance and allowed for determination of key PKs parameters, path of accumulation and excretion rate. Conclusions: The combination of size-controlled distribution of nanoparticles, functionalization with high-specific targeting peptides and Cu-64 radioisotope labelling resulted in highly promising imaging/therapeutic scaffolds, based on gold/iron oxide NPs coated with PEG(4) and bearing specific targeting 64Cu-DOTA-BBN analogs. Their preliminary in vitro and in vivo evaluation shows good results regarding uptake, retention, stability and PKs parameters. Further investigations are to be performed to determine the detailed dosimetry and therapeutic efficacy to extend the potential use to targeted radionuclide therapy, by use of highly cytotoxic potency of Auger-electrons emitted by Cu-64, inside the tumour, and specifically affecting the tumour cell metabolism. Research Support: This work was supported by a grant of the Romanian Ministry of Research and Innovation, UEFISCDI project number 64PCCDI/2018.

Tumor Microenvironment-Responsive Yolk–Shell NaCl@Virus-Inspired Tetrasulfide-Organosilica for Ion-Interference Therapy via Osmolarity Surge and Oxidative Stress Amplification

Ion-interference therapy, which utilizes ions to disturb intracellular biological processes, provides inspiration for tumor therapy. Artificially reversing osmotic pressure by transporting large amounts of physiological ions to tumor cells is a straightforward yet low-toxic strategy for ion-interference therapy. However, it is hard to achieve due to the serious limitations of single-ion delivery. Herein, we skillfully deliver NaCl nanocrystals to tumor sites and sequentially realize the explosive release of Na+/Cl- inside tumor cells by utilizing a virus-mimicking and glutathione (GSH)-responsive hollow mesoporous tetrasulfide-bridged organosilica (ssss-VHMS). Once the ssss-VHMS-wrapped NaCl nanocrystals (NaCl@ssss-VHMS) accumulate in the tumors, they would rapidly invade tumor cells via spike surface-assisted endocytosis, thus bypassing Na+/K+-ATPase transmembrane ion transporters. Afterward, the intracellular overproduced GSH of tumor cells would trigger the rapid degradation of ssss-VHMS via thiol-tetrasulfide exchange, which could not only remarkably deplete the GSH but also explosively release the Na+/Cl-, leading to the osmolarity surge accompanied by reactive oxygen species (ROS) generation. The cell swelling, ROS storm, and GSH exhaustion of NaCl@ssss-VHMS effectively eradicated tumor cells by caspase-1-dependent pyroptosis, caspase-3-dependent apoptosis, and GPX4-dependent ferroptosis, respectively, thus synergistically inhibiting tumor growth. We believe that NaCl@ssss-VHMS would be a potential cancer therapeutic agent, and this discovery could provide a perspective for exploring synergistic ion-interference therapy.

Percutaneous implantation of ethanol fueled catalytic hydrogel suppresses tumor growth by triggering ferroptosis

Percutaneous ethanol injection therapy (PEIT) is a nonthermal locoregional treatment modality widely used in the treatment of solid tumors such as small hepatocellular carcinoma (HCC). Restricted by the inhomogeneous diffusion and unwanted leakage of injected ethanol, PEIT that usually requires multiple injections is often associated with a high local recurrence rate and potential severe complications. Herein, we propose an alternative locoregional treatment strategy to effectively ablate tumors by utilizing the reactive oxygen species generated from the percutaneously implanted catalytic couple fueled by orally administrated ethanol. It is shown that the catalytic couple of alcohol oxidase and iron catalyst hemin conjugated chitosan can sequentially convert ethanol to cytotoxic hydrogen peroxides and then hydroxyl radials, thereby result in efficient cancer cell killing by triggering ferroptosis. Upon being fixed inside tumors with in-situ formed alginate hydrogels, such catalytic couple together with multiple ethanol gavages shows great inhibitory effect on murine H22 liver and 4T1 breast tumors, comparable to those treated by PEIT. The efficient therapeutic potency of the combination treatment is further confirmed in a rat orthotopic N1S1 HCC model. This work highlights that our ‘alcohol drinking’ anti-tumor strategy is of great effectiveness, operation convenience, and high safety.

In Situ Constructed Nano-Drug Depots through Intracellular Hydrolytic Condensation for Chemotherapy of Bladder Cancer.

Intravesical administration of first-line drugs has shown failure in the treatment of bladder cancer owing to the poor tumor retention time of chemotherapeutics. Herein, we report an intracellular hydrolytic condensation (IHC) system to construct long-term retentive nano-drug depots in situ, wherein sustained drug release results in highly efficient suppression of bladder cancer. Briefly, the designed doxorubicin (Dox)-silane conjugates self-assemble into silane-based prodrug nanoparticles, which condense into silicon particle-based nano-drug depots inside tumor cells. Significantly, we demonstrate that the IHC system possesses highly potent antitumor efficacy, which leads to the regression and eradication of large established tumors and simultaneously extends the overall survival of air pouch bladder cancer mice compared with that of mice treated with Dox. The concept of intracellular hydrolytic condensation can be extended via conjugating other chemotherapeutic drugs, which may facilitate rational design of novel nanomedicines for augmentation of chemotherapy.

In Situ Constructed Nano‐Drug Depots through Intracellular Hydrolytic Condensation for Chemotherapy of Bladder Cancer

AbstractIntravesical administration of first‐line drugs has shown failure in the treatment of bladder cancer owing to the poor tumor retention time of chemotherapeutics. Herein, we report an intracellular hydrolytic condensation (IHC) system to construct long‐term retentive nano‐drug depots in situ, wherein sustained drug release results in highly efficient suppression of bladder cancer. Briefly, the designed doxorubicin (Dox)‐silane conjugates self‐assemble into silane‐based prodrug nanoparticles, which condense into silicon particle‐based nano‐drug depots inside tumor cells. Significantly, we demonstrate that the IHC system possesses highly potent antitumor efficacy, which leads to the regression and eradication of large established tumors and simultaneously extends the overall survival of air pouch bladder cancer mice compared with that of mice treated with Dox. The concept of intracellular hydrolytic condensation can be extended via conjugating other chemotherapeutic drugs, which may facilitate rational design of novel nanomedicines for augmentation of chemotherapy.

Mechanical Stress Signaling in Pancreatic Cancer Cells Triggers p38 MAPK- and JNK-Dependent Cytoskeleton Remodeling and Promotes Cell Migration via Rac1/cdc42/Myosin II.

Our findings highlight that mechanical stress activated the p38 MAPK and JNK signaling axis and stimulated pancreatic cancer cell migration via upregulation of the actin cytoskeleton remodelers cdc42 and Rac1.

Increased Targeting Area in Tumors by Dual-Ligand Modification of Liposomes with RGD and TAT Peptides.

Modification with polyethylene glycol (PEGylation) and the use of rigid phospholipids drastically improve the pharmacokinetics of chemotherapeutics and result in more manageable or reduced side-effects. A major drawback is retarded cellular delivery of content, which, along with tumor heterogeneity, are the two main obstacles against tumor targeting. To enhance cellular delivery and reach a bigger area of a tumor, we designed liposomes decorated with two ligands: one for targeting tumor vasculature via a cyclic-pentapeptide containing arginine-glycine-aspartic acid (RGD), which impacts tumor independent of passive accumulation inside tumors, and one for extravascular targeting of tumor cells via a cell-penetrating peptide derived from human immunodeficiency virus type 1 transactivator of transcription (TAT). Liposomes with different ligand combinations were prepared and compared with respect to performance in targeting. Intravital imaging illustrates the heterogeneous behavior of RGD-liposomes in both intravascular and extravascular distribution, whereas TAT-liposomes exhibit a predictable extravascular localization but no intravascular targeting. Dual-ligand modification results in enhanced vascular targeting and a predictable extravascular behavior that improves the therapeutic efficacy of doxorubicin-loaded liposomes but also an augmented clearance rate of liposomes. However, the dual-modified liposome could be a great candidate for targeted delivery of non-toxic payloads or contrast agents for therapeutic or diagnostic purposes. Here we show that the combination of vascular-specific and tumor cell-specific ligands in a liposomal system is beneficial in bypassing the heterogeneous expression of tumor-specific markers.

Nanodrug shows spatiotemporally controlled release of anti-PD-L1 antibody and STING agonist to effectively inhibit tumor progression after radiofrequency ablation

The PD-1/PD-L1 blockade failed to prolong the progression-free survival of patients after radiofrequency ablation (RFA) treatment of liver metastases from colorectal cancers. We found that the PD-1/PD-L1 immune checkpoint blockade (ICB) therapy after RFA in mice model only had a temporary inhibition of tumor progression due to the limited number of mature dendritic cells (DCs) and the insufficient tumor infiltration/activation of cytotoxic T lymphocytes (CTLs). Our study further revealed that the activation of stimulator of interferon gene (STING) affecting tumor-infiltrating DCs and CD8+ T cells was only transient after RFA of tumor. Therefore, a nanovesicle capable of releasing the anti-PD-L1 antibody (αPD-L1) and STING agonist inside tumor in a spatiotemporally controlled manner was developed to evoke a robust anti-cancer immune response and immune memory for a long-term inhibition of tumor progression after RFA. The nanovesicle entrapping the hydrophilic STING agonist 5,6-dimethylxanthenone-4-acetate sodium salt (DMXAAst) in its lumen and anchoring αPD-L1 via an MMP-2-sensitive peptide linker was coated with PEG layer sheddable in acidic tumor microenvironment. The nanodrug design allowed the PEG coating to block off-target interaction between αPD-L1 and PD-L1-positive normal cells in blood and normal tissues, thereby reducing the immune-related adverse effects (irAEs). APD-L1 was firstly released in response to MMP-2 overexpressed in tumor tissue for ICB therapy, which promote the intracellular delivery of DMXAAst to activate STING in DCs. The synergistic effect of αPD-L1, DMXAAst and RFA evoked a robust anti-tumor immunity and long-term immune memory for a potent cancer therapy.