Tumor Tissue Microenvironment Research Articles

Multi-transformable nanocarrier with tumor extracellular acidity-activated charge reversal, size reduction and ligand reemergence for in vitro efficient doxorubicin loading and delivery.

Various nanoparticles as drug delivery system provide significant improvements in the cancer treatment. However, their clinical success remains elusive in large part due to their inability to overcome both systemic and tumor tissue barriers. The nanosystems with nanoproperty-transformability (surface, size, stability and target) hold great promise for achieving enhanced delivery efficacy. However, currently available systems that are mainly polymer-based assemblies usually suffer from the intrinsic drawbacks of poor stability, premature leakage and low drug loading as well as limited transformability. In this study, we designed a facile strategy to build a novel multi-transformable MSNs@GO nanosystem for efficient doxorubicin (DOX) loading and delivery. This novel nanosystem was well characterized and investigated in vitro. The results indicated that the MSNs@GO can realize a very high drug loading ability due to the large pore surface area of MSNs and the demonstrated donor-acceptor (boron‑nitrogen) coordination interactions between phenylboronic acid-containing nanocarriers and electron donor-containing DOX. More importantly, the novel nanocarriers can simultaneously achieve charge reversal, size reduction and ligand reemergence by shielding/deshielding transition via acid-cleavable dynamic boronate bonds under in vitro simulated acidic microenvironment of tumor tissues, opening a new avenue for improving delivery efficiency of chemotherapeutics.

Developing neobavaisoflavone nanoemulsion suppresses lung cancer progression by regulating tumor microenvironment

It is necessary to create novel, efficacious and harmless therapeutic strategy for lung cancer treatment. The application of nanoemulsion to specifically suppress cancer progression in the tumor microenvironment would be an effective therapy. Neobavaisoflavone (Neo) is an isoflavone isolated from Psoralea corylifolia L, possesses striking anti-inflammatory and anti-cancer effects. In our stduy, Neo significantly reduced reactive oxygen species (ROS) generation in the activated myofibroblast. Furthermore, a novel Neo nanoemulsion (nano-Neo) was prepared to improve Neo solubility and bioavailability. Nano-Neo showed more effectively anti-proliferative role in lung cancer cells. In addition, in vivo analysis further demonstrated that nano-Neo could effectively suppress tumor growth compared to the free Neo-treated mice without noticeable damage to major organs. Furthermore, nano-Neo treatment markedly reduced extracellular matrix (ECM) deposition in tumor samples by repressing transforming growth factor-β (TGF-β)/SMADs signaling pathway. Meanwhile, the activated immune microenvironment in tumor tissues was dramatically improved by nano-Neo through reducing regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) infiltration, as well as improving the count of natural killer (NK) cells and M2 macrophage phenotype switch to pro-inflammatory M1. In addition, we found that the prepared nano-Neo exerted promising tumor targeting efficiency with improved pharmacokinetic properties. Therefore, the novel approach to prepare nano-Neo introduced here might provide an effective strategy for lung cancer treatment with few adverse effects.

Modular AND Gate‐Controlled Delivery Platform for Tumor Microenvironment Specific Activation of Protein Activity

Protein therapeutics have inspired intensive research interest in a variety of realms. It is still urgently required to avoid premature or unexpected activation of therapeutic proteins to achieve great specificity for therapy. Herein, we reported a modular AND gate-controlled delivery platform for tumor microenvironment specific activation of therapeutic protein activity based on biomineralization of molecular glue-adhered protein enzyme. The AND gate integrates the specific microenvironment of tumor tissues (acidic pH and a certain concentration of ATP) as inputs and activates the therapeutic activity of protein only when both inputs are active. More importantly, the activity of therapeutic protein would not be activated either at acidic pH or in the presence of ATP, which could greatly avoid the deleterious effect on normal tissues. Besides, this AND gate can be modular design and suitable for a variety of therapeutic proteins and nucleic acids.

Ultrasound-responsive polymersomes capable of endosomal escape for efficient cancer therapy

Stimuli-responsive anticancer drug delivery vehicles have attracted increasing attention in nanomedicine. However, controlled drug release in vivo is still an important challenge, as traditional stimuli lack maneuverability. To solve this problem, we designed an ultrasound and pH-responsive polymersome by self-assembly of poly(ethylene oxide)-block-poly(2-(diethylamino)ethyl methacrylate)-stat-poly(methoxyethyl methacrylate) [PEO-b-P(DEA-stat-MEMA)], where PEO acts as the corona-forming block, DEA acts as the endosomal escape segment, and MEMA acts as the ultrasound-responsive segment. This strategy combines the advantages of noninvasive ultrasonic stimulus which can be applied from outside to any organ regardless of depth, and the weakly acidic microenvironment of tumor tissue. In vitro experiments confirmed excellent endosomal escape ability, on-demand drug release behavior, low cytotoxicity, and high intracellular delivery efficiency of polymersomes. In vivo antitumor tests revealed that in the presence of sonication, the anticancer drug was released at an accelerated rate from these ultrasound-responsive polymersomes, and the DOX-loaded polymersomes + sonication group significantly inhibited tumor growth (95% reduction in tumor mass) without any side effects. Overall, this ultrasound-responsive polymersome provides us with a fresh insight into designing next-generation stimuli-responsive drug carriers with better maneuverability and higher chemotherapeutic efficiency.

Abstract B83: A role of a transcription factor TOX in promoting CD8+ T-cell exhaustion in cancer via single-cell transcriptome analysis

Abstract Recently to treat cancer, several cancer therapies have been developed such as chemotherapy, radiation therapy, immunotherapy, targeted therapy, and hormone therapy. Among several cancer therapies, immunotherapies have recently been developed and shown clinical impacts on a significant number of patients. However, even in the case of immunotherapy, every cancer therapy does not have a 100% response rate. Since the difference in the response rate is mainly due to tumor microenvironment, we need to understand the tumor microenvironment to overcome the low response rate of therapies. Previously, tumor microenvironment was analyzed using cell sorting techniques such as FACS, but it is hard to observe every cell subtype. However, recently, a new technique called single-cell RNA sequencing has been developed. Single-cell RNA sequencing sequences RNAs from every single cell from the sample. Using single-cell RNA sequencing, we can get transcriptome information from whole tumor sample. Therefore, we can observe interactions between the immune cells and the tumors cells using single-cell RNA sequencing. First of all, to focus on the microenvironment of tumor tissue, we analyzed public single-cell RNA sequencing data and unraveled the phenotype of exhausted T cells. By analyzing single-cell RNA sequencing data from the public, we found TOX, a T cell exhaustion-associated transcriptional regulator important for maintaining exhausted T cell. We confirmed that TOX is expressed in the context of exhausted T cell by FACS analysis. Also, using trajectory analysis, we observed expression pattern of TOX through T-cell exhaustion process. Additionally, we analyzed TCGA data to observe the effect of TOX on survival rate. Through analyzing several data such as expression data, binding assay, and open chromatin region of exhausted T cells, we found a potential role of the TOX gene. We also confirmed that the TOX gene can regulate the expression of other checkpoint molecules by knockdown experiment. Here, we found a novel regulator in the tumor microenvironment using single-cell transcriptomics. Citation Format: Kyungsoo Kim, Seyeon Park, Sang-Jun Ha, Insuk Lee. A role of a transcription factor TOX in promoting CD8+ T-cell exhaustion in cancer via single-cell transcriptome analysis [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr B83.

Small Molecular Immune Modulators as Anticancer Agents.

After decades of intense effort, immune checkpoint inhibitors have been conclusively demonstrated to be effective in cancer treatments and thus are revolutionizing the concepts in the treatment of cancers. Immuno-oncology has arrived and will play a key role in cancer treatment in the foreseeable future. However, efforts to find novel methods to improve the immune response to cancer have not ceased. Small-molecule approaches offer inherent advantages over biologic immunotherapies since they can cross cell membranes, penetrate into tumor tissue and tumor microenvironment more easily, and are amenable to be finely controlled than biological agents, which may help reduce immune-related adverse events seen with biologic therapies and provide more flexibility for the combination use with other therapies and superior clinical benefit. On the one hand, small-molecule therapies can modulate the immune response to cancer by restoring the antitumor immunity, promoting more effective cytotoxic lymphocyte responses, and regulating tumor microenvironment, either directly or epigenetically. On the other hand, the combination of different mechanisms of small molecules with antibodies and other biologics demonstrated admirable synergistic effect in clinical settings for cancer treatment and may expand antibodies' usefulness for broader clinical applications. This chapter provides an overview of small-molecule immunotherapeutic approaches either as monotherapy or in combination for the treatment of cancer.

Tumor-mediated shape-transformable nanogels with pH/redox/enzymatic-sensitivity for anticancer therapy.

Lack of sufficient tumor penetration of the current nanomedicines is a major reason limiting their clinical success in cancer therapy. In this work, we aimed at the development of a novel biodegradable nanoplatform for the selective and controlled delivery of anticancer agents, with improved tumor permeability and the ability to release ultrasmall nanovesicles in the tumor microenvironment. To this end, positively charged nanogels were obtained through the double-crosslinking of chitosan with an ionic physical gelator and a disulfide-containing chemical crosslinker. After conjugation to an anionic oligomer, the cationic nanogels were transformed into negatively charged nanocarriers (CTCP), enabling effective encapsulation of the cationic anticancer agent doxorubicin (DOX) to generate a biodegradable nanomedicine (DOX@CTCP). DOX@CTCP could maintain sustained DOX release and decreased DOX toxicity. Upon arrival at the tumor tissue, the reductive and lysozyme-high microenvironment drives the cleavage of the nanomedicine to release DOX-carrying nanoblocks of smaller size, which together with their acidic-protonable feature achieves an effective therapeutic delivery into cancer cells. The nanomedicine described here showed excellent biocompatibility/biosafety and enhanced in vivo antitumor efficacy.

Adenosine Generated by Regulatory T Cells Induces CD8+ T Cell Exhaustion in Gastric Cancer through A2aR Pathway.

Background Adenosine, derived from the degradation of ATP via ectonucleotidases CD39 and CD73, is a critical immunosuppressive metabolite in the hypoxic microenvironment of tumor tissue. Adenosine signaling via A2aR can inhibit the antitumor immune response of CD8+ T cells. CD39 and CD73 high-expressing Tregs play a critical role in tumor immune evasion of gastric cancer (GC). The present study investigated the underlying mechanism by which Tregs suppress antitumor immune responses in GC. Materials and Methods Fifty-two GC samples were collected, and the frequency of FoxP3+ Tregs and CD8+ T cells and density ratios of A2aR+/CD8+ T cells, CD39+/FoxP3+ Tregs, and CD73+/FoxP3+ Tregs in GC were assessed with multiplex immunofluorescence. The expression of FoxP3 and A2aR in GC tissues was also detected by the immunoblotting assay. We next investigated the relationship between density of FoxP3+ Tregs, ratio of A2aR+/CD8+ T cells, and clinicopathological parameters. At the same time, Tregs and CD8+ T cells were isolated from peripheral blood of five GC patients, and the antagonists of CD39 and CD73 were used to assess the ability of Tregs to decompose ATP into adenosine. In addition, we cocultured CD8+ T cells and Tregs with antagonists of A2aR and A2bR in order to examine the alterations in immune function of CD8+ T cells. Results The density of both FoxP3+ Tregs and A2aR+/CD8+ T cells was higher in GC tissue compared to peritumoral normal tissue and significantly correlated with the TNM stage, lymph node metastasis, and distant metastasis of GC. The process of Treg hydrolysis of ATP into adenosine was blocked by the antagonists of CD39 and CD73. In addition, Tregs could induce apoptosis and inhibit proliferation of CD8+ T cells, while this effect could be obviously reduced by applying the antagonist of A2aR or A2aR+A2bR. Moreover, IFN-γ, TNF-α, and perforin generated by CD8+ T cells could also be inhibited through the adenosine A2aR pathway. Conclusions The FoxP3+ Tregs and A2aR+/CD8+ T cells were excessively infiltrated in GC tissue. Tregs from GC can decompose ATP to adenosine and in turn induce apoptosis and inhibit the proliferation of CD8+ T cells through the A2aR pathway, further leading to immune escape of GC.

Stimuli-responsive charge-reversal nano drug delivery system: The promising targeted carriers for tumor therapy.

The stimuli-responsive charge-reversal nano drug delivery system (CRNDDS) for the treatment of tumors has attracted much attention as an effective drug delivery system. The charge-reversal nanocarriers are either uncharged or negatively charged under normal physiological environment; however, they acquire positive charged in tumor tissue microenvironment. The process of charge reversal from negative-to-positive results in not only quick drug release in acidic environment but also enhance the cellular uptake of drug through electrostatic absorptive endocytosis resulting in improvement of cancer therapeutic outcome. In this review, we discuss the recent advances in the study of charge-reversal nanocarriers that could control the distribution of drugs in response to specific stimuli, such as pH, reduced glutathione (GSH) concentration, enzyme concentration, light and thermal stimulation. The applications of CRNDDS in the tumor treatment was also analyzed and summarized.

Enhancing Radiotherapeutic Effect With Nanoparticle-Mediated Radiosensitizer Delivery Guided By Focused Gamma Rays In Lewis Lung Carcinoma-Bearing Mouse Brain Tumor Models.

BackgroundTargeting radiosensitizer-incorporated nanoparticles to a tumor could allow for less normal tissue toxicity with more efficient drug release, thus improving the efficacy and safety of radiation treatment. The aim of this study was to improve tumor-specific delivery and bioavailability of a nanoparticle-mediated radiosensitizer in mouse brain tumor models.MethodsA pH-sensitive nanoparticle, chitoPEGAcHIS, was conjugated to recombinant peptide HVGGSSV that could bind to tax-interaction protein 1 (TIP-1) as a radiation-inducible receptor. Then the c-Jun N-terminal kinase (JNK) inhibitor, SP600125 was incorporated into this copolymer to fabricate a HVGGSSV-chitoPEGAcHIS-SP600125 (HVSP-NP) nanoradiosensitizer. In vitro and in vivo radiation treatment were performed using a Gamma Knife unit. The tumor targetability of HVSP-NP was estimated by optical bioluminescence. Synergistic therapeutic effects of radiation treatment and HVSP-NP were investigated in Lewis lung carcinoma (LLC) cell-bearing mouse brain tumor models.ResultsThe SP600125 JNK inhibitor effectively reduced DNA damage repair to irradiated LLC cells. A pH sensitivity assay indicated that HVSP-NP swelled at acidic pH and increased in diameter, and its release rate gradually increased. Optical bioluminescence assay showed that radiation induced TIP-1 expression in mouse brain tumor and that the nanoradiosensitizer selectively targeted irradiated tumors. Radiation treatment with HVSP-NP induced greater apoptosis and significantly inhibited tumor growth compared to radiation alone.ConclusionAs a novel nanoradiosensitizer, HVSP-NP was found to be able to selectively target irradiated tumors and significantly increase tumor growth delay in LLC-bearing mouse brain tumor models. This research shows that delivering a pH-sensitive nanoradiosensitizer to a brain tumor in which TIP-1 is induced by radiation can result in improved radiosensitizer-release in an acidic microenvironment of tumor tissue and in created synergistic effects in radiation treatment.

Dissociation of solid tumor tissues with cold active protease for single-cell RNA-seq minimizes conserved collagenase-associated stress responses

BackgroundSingle-cell RNA sequencing (scRNA-seq) is a powerful tool for studying complex biological systems, such as tumor heterogeneity and tissue microenvironments. However, the sources of technical and biological variation in primary solid tumor tissues and patient-derived mouse xenografts for scRNA-seq are not well understood.ResultsWe use low temperature (6 °C) protease and collagenase (37 °C) to identify the transcriptional signatures associated with tissue dissociation across a diverse scRNA-seq dataset comprising 155,165 cells from patient cancer tissues, patient-derived breast cancer xenografts, and cancer cell lines. We observe substantial variation in standard quality control metrics of cell viability across conditions and tissues. From the contrast between tissue protease dissociation at 37 °C or 6 °C, we observe that collagenase digestion results in a stress response. We derive a core gene set of 512 heat shock and stress response genes, including FOS and JUN, induced by collagenase (37 °C), which are minimized by dissociation with a cold active protease (6 °C). While induction of these genes was highly conserved across all cell types, cell type-specific responses to collagenase digestion were observed in patient tissues.ConclusionsThe method and conditions of tumor dissociation influence cell yield and transcriptome state and are both tissue- and cell-type dependent. Interpretation of stress pathway expression differences in cancer single-cell studies, including components of surface immune recognition such as MHC class I, may be especially confounded. We define a core set of 512 genes that can assist with the identification of such effects in dissociated scRNA-seq experiments.

Abstract 125: Digital Spatial Molecular Profiling evidence from H&E stained FFPE that the tumor microenvironment confers gene expression phenotype specificity

Abstract Identifying the molecular phenotype of cells within the context of their tumor tissue microenvironment may be critical to understanding cancer and improving patient treatments and outcomes. TempO-Seq® (DOI:10.1371/journal.pone.0178302, doi.org/10.1093/toxsci/kfx153) can be used to profile gene expression from lysates of scraped FFPE tissue down to 2 mm2 areas of 5 μm thick sections. We report use of an in situ TempO-Seq transcriptomic assay carried out on slide-mounted FFPE by an automated stainer (Leica BOND), followed by H&E staining and imaging to perform standard histology. Regions of interest (ROIs) down to 20 μm in diameter are selected at the same time. Probes from these ROIs are automatically eluted, obtaining a detailed gene expression profile. This process is called Digital Spatial Molecular Profiling (DSMP). DSMP was used to profile gene expression from histologically discrete areas within tumor sections. A pan cancer assay of 5,207 genes was used, containing biomarkers for cancer, immune responses and interactions, as well as the S1500v2 whole transcriptome surrogate assay (doi.org/10.1371/journal.pone.0191105), permitting all known molecular pathways to be mapped. Data analysis was carried out using the automated TempO-SeqR™ software package. Replicate areas of cancer, high grade PIN (prostatic intraepithelial neoplasia), normal epithelium, and stroma within prostate cancer FFPE sections were profiled and compared to the profiling of a 2 mm2 scraped area of tissue defined as 100% cancer. What was notable from the DSMP data was that key cancer and immune cell biomarkers were not detected at all in normal, key normal biomarkers were not detected at all in cancer, PIN expressed a collection of normal, cancer and immune biomarkers, and stromal biomarkers were not detected in normal, PIN or cancer glands, while housekeepers were detected in all tissue types. In contrast, housekeeper genes and key biomarkers of cancer, normal, stroma, and immune cells, were all expressed in the 100% pure area of cancer, lacking the biomarker specificity afforded by histologically focused DSMP profiling. The DSMP specificity obtained from the FFPE tissue was striking, leading us to hypothesize that factors within the tumor microenvironment (whether it is adjacent cells, the structural effects of tissue, or sequestration/gradients of extracellular modulators within the tissue) exert molecular specificity on cells within the tissue not present in cultured or dissociated cells devoid of context. Citation Format: Elliot Imler, Raymond Nagle, Bruce Seligmann. Digital Spatial Molecular Profiling evidence from H&E stained FFPE that the tumor microenvironment confers gene expression phenotype specificity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 125.

Abstract 3780: Spatially resolved transcriptional patterns of PARP inhibitor-resistant high grade serous ovarian cancer PDX tissue

Abstract Ovarian cancer is the leading cause of mortality among gynecological malignancies; 70% of patients who initially respond to therapy eventually relapse and die. Within highly heterogeneous tumors, resistance originates from a small number of cells that express beneficial genes and receive favorable cues from their microenvironment. Understanding the mechanisms of drug resistance therefore requires the knowledge of which cell types compose the tumor, which genes they express, and where they are located respective to other cells and tissue landmarks. To this end, we have explored cell type and transcriptional heterogeneity in homologous recombination deficient patient-derived xenograft (PDX) models of high grade serous ovarian cancer (HGSOC) treated with the PARP inhibitor talazoparib. We are using single-cell RNA sequencing (scRNA-seq) to identify the discrete cell types present in drug naïve and drug resistant PDX tissue and to characterize the transcriptional changes driving the resistant phenotype. We are using single-molecule hybridization chain reaction (smHCR) to fluorescently label mRNAs and diSPIM light sheet microscopy to visualize fluorescently labeled mRNAs within large volumes of PDX tissue. We are currently developing computational strategies to deconvolve the 3D spatial organization of PDX cell types and to understand where and when resistance genes are expressed. This integrated scRNA seq and smHCR microscopy framework has allowed us to identify rare cell populations within HGSOC PDXs and to visualize their 3D localization relative to other cell types and tissue features, and it has the potential to elucidate how transcription of key genes supports transition to a resistant state. The insights gained from single cell transcriptional and 3D spatial profiles has the potential to greatly advance our understanding of how the 3D tumor tissue microenvironment allows and encourages rare cells with pre-resistant transcriptional programs to escape PARP inhibitor treatment. Further, this research has the potential to be predictive of disease progression and to suggest additional therapeutic targets that could be exploited as part of novel and/or personalized combination therapy regimens. An additional advantage is that this approach could be generalizable to many types of cancer to characterize the interplay between tissue organization and diverse processes such as tumor evolution, metastasis, and drug resistance. Citation Format: Benjamin King, Elke Van Oudenhove, Selim Misirlioglu, Ernesto Arostegui Fernandez, Douglas Levine, Timothee Lionnet. Spatially resolved transcriptional patterns of PARP inhibitor-resistant high grade serous ovarian cancer PDX tissue [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3780.

Fatty acids distribution and content in oral squamous cell carcinoma tissue and its adjacent microenvironment

Squamous cell carcinoma of the oral cavity mucosa grows under conditions of poor oxygenation and nutrient scarcity. Reprogramming of lipid biosynthesis accompanies tumor growth, but the conditions under which it occurs are not fully understood. The fatty acid content of the serum, tumor tissue and adjacent tumor microenvironment was measured by gas chromatography in 30 patients with squamous cell carcinoma grade 1–3. Twenty-five fatty acids were identified; their frequencies and percentages in each of the environments were assessed. Nineteen of the twenty-five fatty acids were found in tumor tissue, tumor adjacent tissue and blood serum. Of them, 8 were found in all thirty patients. Percentages of C16:0 and C18:1n9 were highest in the tumor, C18:1n9 and C16:0 were highest in tumor adjacent tissue, and C16:0 and C18:0 were highest in blood serum. The frequencies and amounts of C22:1n13, C22:4n6, C22:5n3 and C24:1 in tumor adjacent tissues were higher than those in blood serum, independent of the tumor grade. The correlations between the amount of fatty acid and tumor grade were the strongest in tumor adjacent tissues. The correlations between particular fatty acids were most prevalent for grade 1+2 tumors and were strongest for grade 3 tumors. In the adjacent tumor microenvironment, lipogenesis was controlled by C22:6w3. In blood serum, C18:1trans11 limited the synthesis of long-chain fatty acids. Our research reveals intensive lipid changes in oral cavity SCC adjacent to the tumor microenvironment and blood serum of the patients. Increase in percentage of some of the FAs in the path: blood serum–tumor adjacent microenvironment–tumor, and it is dependent on tumor grade. This dependency is the most visible in the tumor adjacent environment.

An injectable and tumor-specific responsive hydrogel with tissue-adhesive and nanomedicine-releasing abilities for precise locoregional chemotherapy

Locoregional chemotherapy, especially using implantable hydrogel depots to sustainably deliver chemotherapeutics at tumor site, has shown great potential for improving antitumor efficacy and reducing systemic toxicity. However, the hydrogel applications are limited by some intrinsic constraints, especially the contradiction between increasing drug penetration and accumulation in tumor and decreasing random drug diffusion into surrounding normal tissues. Herein, we report a unique “Jekyll and Hyde” nanoparticle-hydrogel (NP-gel) hybrid platform, which can keep dormant in adjacent normal tissues but be activated by mildly acidic and hyaluronidase-rich microenvironment in malignant tumor tissues to unidirectionally release tumor-targeting and penetrative doxorubicin (DOX)-loaded NPs. Apart from tumor-specific recognition, penetration, internalization and release, NP-gel features: shear-thinning behavior for injection, tissue-adhesiveness for continuous on-site activation, and full biodegradability for safe use. Precise delivery was clearly demonstrated in both tumor-grafted and tumor-resected mice. A single peritumoral injection of DOX-loaded NP-gel exhibited a significantly higher drug accumulation in tumor for 3 weeks than in nontarget organs and thus long-term tumor remission. More importantly, significant inhibition in tumor recurrence without detectable toxicity to healthy organs was demonstrated when applied after tumor resection. The designed system displayed long-acting and precise anticancer efficacy, paving the way toward effective tumor locoregional treatment. Statement of SignificanceInjectable hydrogels, allowing sustained drug delivery directly at tumor site, has shown great potential for locoregional chemotherapy. However, how to achieve tumor-specific drug accumulation but meanwhile impede the random drug diffusion into surrounding normal tissues remains an insurmountable challenge, especially considering high drug concentration gradient, higher interstitial fluid pressure and denser extracellular matrix in tumor than adjacent normal tissue. Herein, a ‘Jekyll and Hyde’ nanoparticle-hydrogel hybrid formulation was designed to keep dormant in adjacent normal tissues but be activated by mildly acidic and hyaluronidase-rich microenvironment in malignant tumor tissues to unidirectionally release tumor-targeting and penetrative DOX-loaded nanoparticles, leading to a significant tumor inhibition and antirecurrence efficiency without detectable toxicity to healthy organs, thus presenting great potential for precise locoregional chemotherapy.

An Injectable and Tumor-Specific Responsive Hydrogel with Tissue-Adhesive and Nanomedicine-Releasing Abilities for Precise Locoregional Chemotherapy

Locoregional chemotherapy, especially using implantable hydrogel depots to sustainably deliver chemotherapeutics at tumor site, has shown great potential for improving anti-tumorefficacy and reducing systemic toxicity. However, the hydrogel applications are limited by some intrinsic constraints, especially the contradiction between increasing drug penetration and accumulation in tumor and decreasing random drug diffusion into surrounding normal tissues. Herein, we report a unique “Jekyll and Hyde” nanoparticle-hydrogel (NP-gel) hybrid platform, which can keep dormant in adjacent normal tissues but be activated by mildly acidic and hyaluronidase-rich microenvironment in malignant tumor tissues to unidirectionally release tumor-targeting and penetrative doxorubicin (DOX)-loaded NPs. Apart from tumor-specific recognition, penetration, internalization and release, NP-gel features:shear-thinning behavior for injection, tissue-adhesiveness for continuous on-site activation, and full biodegradability for safe use. Precise delivery was clearly demonstrated in both tumor-grafted and tumor-resected mice. A single peritumoral injection of DOX-loaded NP-gelexhibited a significantly higher drug accumulation in tumor for 3 weeks than in nontargetorgans and thus long-term tumor remission. More importantly, significant inhibition in tumor recurrence without detectable toxicity to healthy organs was demonstrated when applied after tumor resection. The designed system displayed long-acting and precise anticancer efficacy,paving the way toward effective tumor locoregional treatment.

In vitro vascularized liver and tumor tissue microenvironments on a chip for dynamic determination of nanoparticle transport and toxicity.

This paper presents the development of a vascularized breast tumor and healthy or tumorigenic liver microenvironments-on-a-chip connected in series. This is the first description of a vascularized multi tissue-on-a-chip microenvironment for modeling cancerous breast and cancerous/healthy liver microenvironments, to allow for the study of dynamic and spatial transport of particles. This device enables the dynamic determination of vessel permeability, the measurement of drug and nanoparticle transport, and the assessment of the associated efficacy and toxicity to the liver. The platform is utilized to determine the effect of particle size on the spatiotemporal diffusion of particles through each microenvironment, both independently and in response to the circulation of particles in varying sequences of microenvironments. The results show that when breast cancer cells were cultured in the microenvironments they had a 2.62-fold higher vessel porosity relative to vessels within healthy liver microenvironments. Hence, the permeability of the tumor microenvironment increased by 2.35- and 2.77-fold compared with a healthy liver for small and large particles, respectively. The extracellular matrix accumulation rate of larger particles was 2.57-fold lower than smaller particles in a healthy liver. However, the accumulation rate was 5.57-fold greater in the breast tumor microenvironment. These results are in agreement with comparable in vivo studies. Ultimately, the platform could be utilized to determine the impact of the tissue or tumor microenvironment, or drug and nanoparticle properties, on transport, efficacy, selectivity, and toxicity in a dynamic, and high-throughput manner for use in treatment optimization.

Redox/pH dual-stimuli responsive camptothecin prodrug nanogels for “on-demand” drug delivery

At present, chemotherapy remains to be one of the most important therapeutic approaches for malignant tumors. The tumor microenvironment(TME)-responsive intelligent drug delivery systems are still the hot research topics in delivering chemotherapeutic drugs. Camptothecin (CPT) possesses very strong antitumor activities, but its clinical application is hindered by its poor water-solubility and serious toxic side effects. Herein, a new intelligent and TME-responsive P(CPT-MAA) prodrug nanogel was developed for delivering CPT and reducing its side effects. P(CPT-MAA) prodrug nanogels were prepared with methacrylic acid (MAA), CPT monomer (CPTM) and N,N′-methylenebisacrylamide (Bis) via distillation-precipitation polymerization, in which CPT was covalently conjugated into the nanogels via redox-responsive disulfide linker. The as-prepared nanogels were spherical shapes with uniform size and narrow size distribution. With the help of redox-responsive property of disulfide linker and pH-responsive property of PMAA, the release of CPT from prodrug nanogels was redox/pH-dual dependent and could be accelerated by the increased concentration of GSH and the decreased pH value, which were favorable to realize the “on-demand” drug release in tumor cell and tumor tissue microenvironment. Furthermore, P(CPT-MAA) prodrug nanogels exhibited superior antitumor activity both in vitro and in vivo without observed side effects. Hence, the prepared P(CPT-MAA) prodrug nanogels may be a promise delivery system for chemotherapeutic agents.

Transcriptomic Signatures Related to the Obesity Paradox in Patients with Clear Cell Renal Cell Carcinoma

Background: Obesity, defined as body mass index (BMI ≥ 30 kg/m2), is associated with an increased risk of developing clear cell renal cell carcinoma (ccRCC) but, paradoxically, also with improved oncologic outcomes in clinical cohorts. This obesity paradox has been described among ccRCC patients with localized disease treated with nephrectomy alone, and those with metastatic disease receiving targeted therapy. The mechanisms underlying these associations are not well understood. Methods: After confirming the inverse association between BMI and mortality among a cohort of 453 metastatic ccRCC patients treated with first-line VEGF-directed therapy, 152 predominately early stage ccRCC patients from the KIRC TCGA, and an observational cohort of 203 metastatic ccRCC patients treated with targeted immunotherapy, we evaluated gene expression differences between obese and normal weight patients. Tumor transcriptomic patterns were compared between obese and normal weight patients in COMPARZ and validated in early-stage patients from the KIRC TCGA cohort. We additionally explored gene expression differences in the peritumoral fat from a prospectively collected cohort of 62 patients with non-metastatic disease. Findings: Gene expression analyses implicate differences in angiogenic and immune cell programs in the tumor microenvironment as possible drivers of the obesity paradox. We also found increased perinephric adipose tissue inflammation near the primary tumor in obese versus normal weight patients. Peritumoral adipose tissue inflammation may be related to increased hypoxia among obese patients, which is more pronounced near the primary tumor. Interpretation: Molecular changes in both the tumor and peritumoral fat may contribute to the apparent survival advantage experienced by obese ccRCC patients. The complex interplay between the ccRCC tumor and peritumoral adipose tissue microenvironment may have clinical relevance and warrants further investigation. Funding: ASCO Young Investigator Award (AS), Chanel grant (HF) and SOAR grant (HF & AJD), Ludwig Center MSKCC (AAH, FK, HF), Ruth L. Kirschstein Research Service Award T32CA082088 (AS), and P30CA08748 MSK Center Support Grant. Declaration of Interest: M.H. Voss reports receiving commercial research grants from BMS and Genentech, is a consultant/advisory board member for Alexion Pharmaceuticals, Calithera Biosciences, Corvus Pharmaceuticals, Exelixis, Eisai, Natera, Novartis, and Pfizer, and has received other remuneration from Eisai, Takeda, and Novartis. N. Riaz reports receiving commercial research grants from BMS and Pfizer and honoraria from the speaker’s bureau of Illumina. Y. Cheng owns stock in Novartis Pharm Inc. M.O. Li is a consultant/advisory board member for Leap Therapeutics. T.A. Chan reports receiving commercial research grants from Illumina, BMS, Eisai, AstraZeneca, and An2H, has ownership interest (including stock, patents, etc.) in Gritstone Oncology, and is a consultant/advisory board member for Gritstone Oncology,Illumina, and Bristol Myers. R.J. Motzer reports receiving commercial research grants from Bristol-Myers Squibb, Pfizer, Novartis, Genentech/Roche, and Eisai and is a consultant/advisory board member for Genentech, Pfizer, Merck, Novartis, and Incyte. A.J. Dannenberg is a member of the scientific advisory boards of SynDevRx and Quentis. No potential conflicts of interest were disclosed by the other authors. Ethical Approval: We conducted an Institutional Review Board (IRB)-approved retrospective observational study investigating the clinical significance of pre-treatment BMI and OS in the context of targeted immunotherapy among 203 patients with metastatic ccRCC.

PH-responsive targeted gold nanoparticles for in vivo photoacoustic imaging of tumor microenvironments.

The acidic microenvironment of tumor tissues has been proven to be a major characteristic for differentiation from normal tissues, thereby providing a desirable target for both disease diagnosis and functional imaging. We herein introduce a way to endow gold nanoparticles with aggregation behaviour induced by pH tuning. The nanoparticle surface was modified with two thiol conjugate molecules, which could smartly stabilize it at the pH of blood and normal tissues but induce aggregation in response to the acidic extracellular pH in tumor. The surface conjugate molecule composition effect was studied systematically, and at the optimal surface conjugate molecule composition, a pH-responsive active tumor-targeting c(RGDyk)-MHDA/LSC@AuNP nanoprobe was successfully obtained and showed a significantly enhanced contrast effect for both in vitro and in vivo photoacoustic (PA) imaging. Intravenous administration of our nanoprobe to U87MG tumor-bearing nude mice showed PA imaging contrasts almost 3-fold higher than those for the blocking group. Quantitative biodistribution data revealed that 9.7 μg g−1 of nanoprobe accumulated in the U87MG tumor 4 h post-injection. These findings might provide an effective strategy for developing new classes of intelligent and biocompatible contrast agents with a high efficiency for PA imaging and PA imaging-guided cancer therapy.