Regulation Of Tumor Microenvironment Research Articles

Abstract C021: Tumor-associated microbiota suppresses anti-tumor immunity by driving cDC1 dysfunction in lung cancer

Abstract Type 1 conventional dendritic cells (cDC1s) are critical for initiating and sustaining tumor-reactive CD8 T cells; lack of functional cDC1s is a key driver for failed tumor immunosurveillance and immunotherapy. However, what factors cause the cDC1 insufficiency in the tumor microenvironment (TME) remain poorly understood. Commensal microbiota has emerged as a key regulator of TME and the efficacy of cancer immunotherapies. Nonetheless, most studies have focused on the intestinal microbiome; it remains underexplored whether and how the local microbiota within tumors influences the anti-cancer immunity. Using the autochthonous Kras LSL-G12D/+ ; p53 flox/flox (KP) mouse model of lung cancer, we found an increased local bacterial burden and altered bacterial composition associated with lung tumors. Importantly, this local microbiota suppresses the anti-tumor CD8 T cell response both at baseline and in response to ICB therapies. Specifically, single-cell RNA-seq analysis revealed that the microbiota shapes the functional subsets of tumor-reactive CD8 T cells. Bacterial depletion promotes the accumulation of stem-like Tpex cells (precursor of exhausted T cells) in the TME, which serve as a reservoir of effector CD8 T cells and mediate an effective response upon ICB treatment. To distinguish the function of the local microbiota within TME from the distal gut microbiota, we developed a new method of aerosolized antibiotic treatment, which selectively ablates the intra-tumoral lung microbiota while preserving the intact gut microbiota. Using this approach, we demonstrated that removal of the intra-tumoral lung microbiota markedly improves the tumor-reactive T cell response and sensitizing “cold” lung tumors to ICB therapies. Mechanistically, we identified cDC1s as a central player in microbiota-mediated suppression of anti-tumor immunity. Local microbiota diminishes cDC1 quality and quantity in the lung TME, resulting in impaired T cell priming and Tpex maintenance. At the molecular level, our data revealed that bacterial products derived from the local microbiota induce type I interferon expression in tumor-associated myeloid cells and enhance GM-CSF production from cancer cells: chronic type I interferon and GM-CSF signaling acts cooperatively to reduce the functional cDC1 population. Combining in vitro cDC1 assays, competitive bone marrow chimera experiments and cDC1-specific knockout models, we establish the causal relationships between the local microbiota, IFN-I and GM-CSF signaling in cDC1s, and the tumor response to ICB. Altogether, our study uncovered a dominant role of tumor-associated microbiota in inhibiting cDC1s and suppressing anti-tumor immunity through type I IFN and GM-CSF dependent pathways in lung cancer. Our findings not only identify the intra-tumoral microbiota as a critical therapeutic target for lung cancer treatment, but also provide new insights into the tissue-specific, context-dependent regulatory mechanisms of cDC1s in the TME. Citation Format: Qiang Dong, Chengcheng Jin. Tumor-associated microbiota suppresses anti-tumor immunity by driving cDC1 dysfunction in lung cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C021.

Multi-omics analysis of the biological function of the VEGF family in colon adenocarcinoma.

The vascular endothelial growth factor (VEGF) family plays a crucial role in cancer progression, but the prognostic significance and biological functions of VEGF family members in colon adenocarcinoma (COAD) remain unclear. Using data from The Cancer Genome Atlas, Gene Expression Omnibus, Gene Set Cancer Analysis, cBioPortal, GeneMANIA, String, MethSurv and starBase database, we identified vascular endothelial growth factor B (VEGFB) as a key gene associated with COAD prognosis, with its abnormal expression linked to methylation dysregulation. In vitro experiments confirmed VEGFB expression was significantly higher in colon cancer tissues compared to normal tissues, as shown by Real-time quantitative PCR and immunohistochemistry. Cell Counting Kit-8 and colony formation assay showed that decreased VEGFB expression in SW480 cells resulted in decreased cell viability and proliferation ability. Scratch assay showed that VEGFB downregulation impaired SW480 cell migration. In addition, our research suggests that VEGFB not only promotes angiogenesis but is also involved in the tumor microenvironment and immune regulation. The SHNG17-miR-375-VEGFB regulatory axis provides a potential therapeutic target for COAD, highlighting VEGFB's role in immune activation during anti-angiogenic therapy and potential reversal of drug resistance.

RNA methylation patterns of tumor microenvironment cells regulate prognosis and immunotherapeutic responsiveness in patients with triple-negative breast cancer

Immunotherapy research focuses on reshaping the tumor microenvironment (TME) to enhance its antitumor immune responses, with an emphasis on understanding the impact of RNA methylation in triple-negative breast cancer (TNBC) TME regulation. This study explored the influence of various RNA methyltransferases on TME cells in TNBC and their correlation with prognosis and immunotherapy response. Using non-negative matrix factorization on single-cell RNA-sequencing data, distinct TME cell clusters were identified based on the expression of 30 RNA methyltransferases. Various analyses, including pseudotime, cell communication, transcription factor regulatory network, and gene enrichment, were conducted on these clusters. The roles of RNA methyltransferase-mediated TME clusters in prognosis and immunotherapy response were determined using TNBC bulk RNA-Seq data, and the findings were validated through immunofluorescence analysis of a tissue microarray comprising 87 samples. Spatial transcriptomic analysis further revealed the distribution of TME cell clusters. Different methyltransferase-mediated cell clusters exhibited unique metabolic, immune, transcriptional, and intercellular communication patterns. Survival analysis indicated prognostic significance in specific TME cell clusters, and immunofluorescence analysis confirmed the prognostic value of m6A_WTAP + CD8T + cells. In conclusion, our study illustrated the involvement of these cell subgroups in tumor growth and antitumor immunity modulation, providing insights into the enhancement of TNBC immunotherapy.

Synergistic Potential of Nanomedicine in Prostate Cancer Immunotherapy: Breakthroughs and Prospects.

Given the global prevalence of prostate cancer in men, it is crucial to explore more effective treatment strategies. Recently, immunotherapy has emerged as a promising cancer treatment due to its unique mechanism of action and potential long-term effectiveness. However, its limited efficacy in prostate cancer has prompted renewed interest in developing strategies to improve immunotherapy outcomes. Nanomedicine offers a novel perspective on cancer treatment with its unique size effects and surface properties. By employing targeted delivery, controlled release, and enhanced immunogenicity, nanoparticles can be synergized with nanomedicine platforms to amplify the effectiveness of immunotherapy in treating prostate cancer. Simultaneously, nanotechnology can address the limitations of immunotherapy and the challenges of immune escape and tumor microenvironment regulation. Additionally, the synergistic effects of combining nanomedicine with other therapies offer promising clinical outcomes. Innovative applications of nanomedicine include smart nanocarriers, stimulus-responsive systems, and precision medicine approaches to overcome translational obstacles in prostate cancer immunotherapy. This review highlights the transformative potential of nanomedicine in enhancing prostate cancer immunotherapy and emphasizes the need for interdisciplinary collaboration to drive research and clinical applications forward.

SFRP1 mediates cancer-associated fibroblasts to suppress cancer cell proliferation and migration in head and neck squamous cell carcinoma

BackgroundCancer-associated fibroblasts (CAFs), as key cell populations in the tumor microenvironment (TME), play a crucial role in tumor regulation. Previous studies on a prognostic signature of 8 CAF-related genes in head and neck squamous cell carcinoma (HNSCC) revealed that Secreted frizzled-related protein 1 (SFRP1) is one of the hub genes closely related to CAFs. SFRP1 is deficiently expressed in numerous types of cancer and is classified as a tumor suppressor gene. However, the role of SFRP1 in TME regulation in HNSCC remains unclear. This study aimed to explore the role of SFRP1 in the proliferation and migration of HNSCC cells by mediating CAFs and their regulatory mechanisms.MethodsThe expression differences, prognosis, and immune infiltration of SFRP1 in HNSCC were analyzed using the TIMER and GEPIA2 databases. The expression of SFRP1 in HNSCC tumor tissues, as well as the expression and secretion of SFRP1 in CAFs and tumor cells, were examined. An indirect co-culture system was constructed to detect the proliferation, migration, and apoptosis of HNSCC cells, and to clarify the effect of SFRP1 on tumor cells by mediating CAFs. Furthermore, the expression and secretion of 10 cytokines derived from CAFs that act on immune cells were verified.ResultsSFRP1 was differently expressed in HNSCC tumor tissues and highly expressed in CAFs. SFRP1 inhibited the proliferation and migration of tumor cells and promoted apoptosis by mediating CAFs. The detection of CAFs-derived factors suggested that the mechanism of action of SFRP1 was associated with the regulation of immune cells.ConclusionSFRP1 inhibits the proliferation and migration of HNSCC cells by mediating CAFs, and the mechanism of action is related to the regulation of immune cells, which may provide new research directions and therapeutic targets for HNSCC.

Abstract PR-02: Uncovering molecular differences in pancreatic ductal adenocarcinoma tissues from Black and White patients in the US

Abstract Background: Pancreatic cancer (PC) is among the leading causes of cancer-related deaths in the United States, with a 5-year survival rate of approximately 13%. Previous studies reported higher PC incidence and mortality rates among Black or African American (BAA) patients in comparison to White patients. Disadvantaged socioeconomic status (SES) and environmental exposure to chemicals are factors contributing to racial disparities in pancreatic cancer. Whether and how biological pathways play roles in disparities in pancreatic cancer is unclear. The understanding of molecular features associated racial backgrounds in pancreatic cancer will have significant impacts on both scientific inquiry on cancer biology and clinical management of pancreatic malignancy. In this study, we examined oncogene alterations and PD-L1 expression in pancreatic cancer patients of diverse racial backgrounds. Methods: We conducted our study by analyzing clinical test results of patients through a collaboration with Tempus Labs. In total, 4,249 pancreatic cancer patients’ (White: 3797 and BAA: 452) information were included in this study. DNA target panel sequencing was performed to identify genomic mutations. Genomic microsatellite instability (MSI) and tumor mutational burdens (TMB) were assessed. We also evaluated PD-L1 expression by immunohistochemistry. Results: DNA sequencing analysis revealed differential gene mutation profiles between White and BAA patients. We observed higher rates of KRAS (79.2% vs. 74.2%, q=0.14), TP53 (69.9% vs. 61.9%, q=0.014), KMT2C (6.9% vs. 2.3%, q=0.001), RNF43 (6% vs. 3.7%, q=0.14), and KMT2D (4.4% vs. 2.8%, q=0.3) mutations among BAA patients compared to White patients whereas fewer GNAS (0.2% vs 1.6%, q=0.14) mutation occur in the BAA group. Importantly, the KRAS mutant allele KRASG12R was significantly enriched in BAA compared to White patients (14.4% vs. 10.1%). Next, we compared the TMB levels and found that BAA patients showed higher average TMB levels when compared to White patients. Further, we determined the expression of PD-L1 between the two racial groups and observed BAA patients had more frequent PD-L1 overexpression than White patients (13.2% vs. 8.6%, p<0.05). Interestingly, the race associated difference in PD-L1 expression was even more remarkable in female groups (14.1% vs. 8%, p<0.05). Conclusion: We observed differences in mutation profiles of oncogenes between BAA and White patients, suggesting that such molecular-level changes may contribute to the higher incidence among BAA patients. Additionally, higher frequencies of PD-L1 upregulation in BAA patients implicate racial backgrounds influence tumor microenvironment regulation in pancreatic cancer patients. It is imperative to improve racial diversity in translational and clinical studies. Citation Format: Saurabh Mandal, Emily A Teslow, Minxuan Huang, Swathi Sridhar, Howard Crawford, Melissa C Stoppler, Albert Levin, Ling Huang. Uncovering molecular differences in pancreatic ductal adenocarcinoma tissues from Black and White patients in the US [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr PR-02.

Cancer-associated fibroblasts barrier breaking via TGF-β blockade paved way for docetaxel micelles delivery to treat pancreatic cancer

TGF-β is a crucial regulator in tumor microenvironment (TME), especially for myofibroblastic cancer-associated fibroblasts (myCAFs). The myCAFs can be motivated by TGF-β signaling to erect pro-tumor TME, meanwhile, myCAFs overexpress TGF-β to mediate the crosstalk between tumor and stromal cells. The blockade of TGF-β can break cancer-associated fibroblasts barrier, consequently opening the access for drugs into tumor. The TGF-β is a promising target in anti-tumor therapy. Herein, we introduced a two-stage combination therapy (TC-Therapy), including TGF-β receptor I inhibitor SB525334 (SB) and cytotoxicity agent docetaxel micelle (DTX-M). We found that SB and DTX-M synergistically inhibited myCAFs proliferation and elevated p53 protein expression in BxPC-3/3T3 mixed cells. Gene and protein tests demonstrated that SB cut off TGF-β signaling via receptor blockade and it did not arouse TGF-β legend compensated internal autocrine. On the contrary, two agents combined decreased TGF-β secretion and inhibited myCAFs viability marked by α-SMA and FAPα. TC-Therapy was applied in BxPc-3/3T3 mixed tumor-bearing mice model. After TC-Therapy, the α-SMA+/ FAPα+ myCAFs faded increasingly and collagenous fibers mainly secreted by myCAFs decreased dramatically as well. More than that, the myCAFs barrier breaking helped to normalize micro-vessels and paved way for micelle penetration. The TGF-β protein level of TC-Therapy in TME was much lower than that of simplex DTX-M, which might account for TME restoration. In conclusion, TGF-β inhibitor acted as the pioneer before nano chemotherapeutic agents. The TC-Therapy of TGF-β signaling inhibition and anti-tumor agent DTX-M is a promising regimen without arising metastasis risk to treat pancreatic cancer. The therapeutic regimen focused on TGF-β related myCAFs reminds clinicians to have a comprehensive understanding of pancreatic cancer.

Synthesis, structural characterization, molecular docking analysis and Carbonic Anhydrase IX inhibitory evaluations of novel Cerium(III)-based MOF constructed from 1,10-phenanthroline and fumaric acid.

In this study, a novel Cerium-based MOFs with 1,10-phenanthroline (phen) and fumaric acid (H2fum) has been hydrothermally synthesized as single crystal structurally characterized by X-ray diffraction, IR spectroscopy and ATG measurements. This compound corresponds to the formula: [Ce2(phen)2(fum)3(H2O)2]n(I), it crystallizes in the triclinic system with space group P1¯, with the following parameters: a = 9.062(1) Å, b = 10.0608(5) Å, c = 10.603(1) Å, α = 72.545(6) °, β = 77.57(1) °, γ = 69.959(6) °, V = 859.49(14) Å3, Z = 2.The structure revealed 2D bridged polymeric chains where the adjacent Ce(III) atoms are bridged by fumarate linkers with a mean intermetallic distance of about 9.36 Å. H···O bonds link the 2D sheets leading to a pseudo 3D network, while the stability of the structure is assured by a weak π-π stacking between parallel and opposed phen ligands.The Ce3+ cation is nona-coordinated and it is in a distorted tricapped trigonal prism geometry.Hirshfeld surface analysis was used to investigate the non-covalent intermolecular interactions and the dominant H···O, H···C and H···H contacts were quantified. The thermal properties of the considered coordination polymer (I) are also discussed and disclose that (I) is stable up to 300°C. Besides, this study explores the potential of (I) as an inhibitor of the carbonic anhydrase IX enzyme (CA IX), a critical player in tumor microenvironment regulation. Through molecular docking simulations, we elucidate the binding interactions between (I) and CA IX, the results suggest the efficiency of (I) as a CA IX inhibitor. Moreover, we assessed the drug-likeness properties and ADMET characteristics of (I), providing valuable insights for its potential as a therapeutic agent.

In vivo CRISPR screens identify a dual function of MEN1 in regulating tumor–microenvironment interactions

Functional genomic screens in two-dimensional cell culture models are limited in identifying therapeutic targets that influence the tumor microenvironment. By comparing targeted CRISPR–Cas9 screens in a two-dimensional culture with xenografts derived from the same cell line, we identified MEN1 as the top hit that confers differential dropout effects in vitro and in vivo. MEN1 knockout in multiple solid cancer types does not impact cell proliferation in vitro but significantly promotes or inhibits tumor growth in immunodeficient or immunocompetent mice, respectively. Mechanistically, MEN1 knockout redistributes MLL1 chromatin occupancy, increasing H3K4me3 at repetitive genomic regions, activating double-stranded RNA expression and increasing neutrophil and CD8+ T cell infiltration in immunodeficient and immunocompetent mice, respectively. Pharmacological inhibition of the menin–MLL interaction reduces tumor growth in a CD8+ T cell-dependent manner. These findings reveal tumor microenvironment-dependent oncogenic and tumor-suppressive functions of MEN1 and provide a rationale for targeting MEN1 in solid cancers.

Regulation of Tumor Microenvironment through YAP/TAZ under Tumor Hypoxia.

In solid tumors such as hepatocellular carcinoma (HCC), hypoxia is one of the important mechanisms of cancer development that closely influences cancer development, survival, and metastasis. The development of treatments for cancer was temporarily revolutionized by immunotherapy but continues to be constrained by limited response rates and the resistance and high costs required for the development of new and innovative strategies. In particular, solid tumors, including HCC, a multi-vascular tumor type, are sensitive to hypoxia and generate many blood vessels for metastasis and development, making it difficult to treat HCC, not only with immunotherapy but also with drugs targeting blood vessels. Therefore, in order to develop a treatment strategy for hypoxic tumors, various mechanisms must be explored and analyzed to treat these impregnable solid tumors. To date, tumor growth mechanisms linked to hypoxia are known to be complex and coexist with various signal pathways, but recently, mechanisms related to the Hippo signal pathway are emerging. Interestingly, Hippo YAP/TAZ, which appear during early tumor and normal tumor growth, and YAP/TAZ, which appear during hypoxia, help tumor growth and proliferation in different directions. Peculiarly, YAP/TAZ, which have different phosphorylation directions in the hypoxic environment of tumors, are involved in cancer proliferation and metastasis in various carcinomas, including HCC. Analyzing the mechanisms that regulate the function and expression of YAP in addition to HIF in the complex hypoxic environment of tumors may lead to a variety of anti-cancer strategies and combining HIF and YAP/TAZ may develop the potential to change the landscape of cancer treatment.

Targeting MELK in tumor cells and tumor microenvironment: from function and mechanism to therapeutic application.

Maternal embryonic leucine zipper kinase (MELK), a member of the adenosine monophosphate-activated protein kinase (AMPK) protein family, has been reported to be involved in the regulation of many cellular events. The aberrant expression of MELK is associated with tumorigenesis and malignant progression of various tumors. Moreover, MELK plays an essential role in the regulation of tumor microenvironment (TME), which affects the function of immune cells and the responsiveness to immunotherapy. Currently, small molecule inhibitors targeting MELK have been developed and evaluated in clinical trials. A comprehensive understanding of MELK may provide clues and confidence for subsequent basic research and scientific transformation. In this review, we provide a comprehensive overview of the structural features, molecular biological functions, and critical roles of MELK in tumors and TME, as well as the targeted agents under development for the treatment of tumors and discuss the perspective for MELK-targeted therapies for tumors.

A cuproptosis-based nanomedicine suppresses triple negative breast cancers by regulating tumor microenvironment and eliminating cancer stem cells

Cuproptosis is a new kind of cell death that depends on delivering copper ions into mitochondria to trigger the aggradation of tricarboxylic acid (TCA) cycle proteins and has been observed in various cancer cells. However, whether cuproptosis occurs in cancer stem cells (CSCs) is unexplored thus far, and CSCs often reside in a hypoxic tumor microenvironment (TME) of triple negative breast cancers (TNBC), which suppresses the expression of the cuproptosis protein FDX1, thereby diminishing anticancer efficacy of cuproptosis. Herein, a ROS-responsive active targeting cuproptosis-based nanomedicine CuET@PHF is developed by stabilizing copper ionophores CuET nanocrystals with polydopamine and hydroxyethyl starch to eradicate CSCs. By taking advantage of the photothermal effects of CuET@PHF, tumor hypoxia is overcome via tumor mechanics normalization, thereby leading to enhanced cuproptosis and immunogenic cell death in 4T1 CSCs. As a result, the integration of CuET@PHF and mild photothermal therapy not only significantly suppresses tumor growth but also effectively inhibits tumor recurrence and distant metastasis by eliminating CSCs and augmenting antitumor immune responses. This study presents the first evidence of cuproptosis in CSCs, reveals that disrupting hypoxia augments cuproptosis cancer therapy, and establishes a paradigm for potent cancer therapy by simultaneously eliminating CSCs and boosting antitumor immunity.

Current perspectives and trends of CD39-CD73-eAdo/A2aR research in tumor microenvironment: a bibliometric analysis.

Extracellular adenosine (eAdo) bridges tumor metabolism and immune regulation. CD39-CD73-eAdo/A2aR axis regulates tumor microenvironment (TME) and immunotherapy response. In the era of immunotherapy, exploring the impact of the CD39-CD73-eAdo/A2aR axis on TME and developing targeted therapeutic drugs to enhance the efficacy of immunotherapy are the current research hotspots. This study summarizes and explores the research trends and hotspots of the adenosine axis in the field of TME to provide ideas for further in-depth research. Literature information was obtained from the Web of Science core collection database. The VOS viewer and the bibliometric tool based on R were used to quantify and identify cooperation information and individual influence by analyzing the detailed information of the global annual publication volume, country/region and institution distribution, article authors and co-cited authors, and journal distribution of these articles. At the same time, the distribution of author keywords and the co-occurrence of author keywords, highly cited articles, and highly co-cited references of CD39-CD73-eAdo/A2aR in the field of TME were analyzed to determine research hotspots and trends. 1,721 articles published in the past ten years were included in this study. Through bibliometric analysis, we found that (1) 69 countries and regions explored the effect of the CD39-CD73-eAdo/A2aR on TME, and the research was generally on the rise. Researchers in the United States dominated research in this area, with the highest total citation rate. China had the most significant number of publications. (2) Harvard University has published the most articles in this field. (3) 12,065 authors contributed to the publication of papers in this field, of which 23 published at least eight papers. STAGG J had significant academic influence, with 24 published articles and 2,776 citations. Co-cited authors can be clustered into three categories. Stagg J, Allard B, Ohta A, and Antonioli, L occupied a central position in the network. (4) 579 scholarly journals have published articles in this field. The journal FRONTIERS IN IMMUNOLOGY published the most significant number of papers, with 97 articles and a total of 2,317 citations, and the number of publications increased year by year. (5) "The ectonucleotidases CD39 and CD73: Novel checkpoint inhibitor targets" was the most frequently local cited article (163 times). The "A2A adenosine receptor protects tumors from antitumor T cells" was the most co-cited reference (224 times). (6) Through the analysis of author keywords, we found that the relationship between adenosine and immunotherapy was a core concept for many researchers in this field. Breast cancer, melanoma, colorectal cancer, ovarian cancer, glioblastoma, pancreatic cancer, hepatocellular carcinoma, and lung cancer were the most frequent cancer types in adenosine-related tumor studies. Immunotherapy, immunosuppression, immune checkpoint, and immune checkpoint inhibitors were the hot keywords in the research, reflecting the importance of the adenosine metabolic pathway in tumor immunotherapy. The keywords such as Immunogenic cell death, T cells, Sting, regulatory T cells, innate immunity, and immune infiltration demonstrated the pathways by which adenosine affected the TME. The famous author keywords in recent years have been immunotherapy, immunogenic cell death, inflammation, lung cancer, and gastric cancer. The effect of CD39-CD73-eAdo/A2aR on the infiltration and function of various immune cells in TME, tumor immunotherapy response, and patient prognosis has attracted the attention of researchers from many countries/regions. American scholars still dominate the research in this field, but Chinese scholars produce the most research results. The journal FRONTIERS IN IMMUNOLOGY has published the wealthiest research in the field. Stagg J was a highly influential researcher in this field. Further exploration of targeted inhibition of CD39-CD73-eAdo/A2aR alone or in combination with other immunotherapy, radiotherapy, and chemotherapy in treating various cancer types and developing effective clinical therapeutic drugs are continuous research hotspots in this field.

H2S-Responsive NIR-II Fluorescent Nanozyme that Regulates Tumor Microenvironment for Activatable Synergistic CO Therapy/Catalytic Therapy/Immunotherapy.

Nanozyme catalytic therapy triggered by the tumor microenvironment (TME)-responsive enzyme-like catalytic activities is an emerging approach for tumor treatment. However, the poor catalytic efficiency of nanozymes in tumors and the toxic side effects on normal tissues limit their further development, primarily due to the limited uptake and penetration depth of nanozyme in tumor tissues. Here, a tumor-targeting TME and electric field stimuli-responsive nanozyme (AgPt@CaCO3-FA) is developed, which is capable of catalyzing the generation of ROS to induce cell death and releasing carbon monoxide (CO) specifically in tumor tissues for on-demand CO therapy and immunotherapy. Benefiting from the endogenous H2S activated NIR-II fluorescence (FL) imaging guidance, AgPt@CaCO3-FA can be delivered into the deeper site of tumor tissues resulted from the TME regulation via generated CO during the electrolysis process to improve the catalytic efficiency of nanozymes in tumors. Moreover, CO effectively relieve immunosuppression TME via reeducating tumor-supportive M2-like macrophages to tumoricidal M1-like macrophages and induce mitochondrial dysfunction by reducing mitochondrial membrane potential, triggering tumor cells apoptosis. The enzyme-like activities combined with CO therapy arouse distinct immunogenic cell death (ICD) effect. Therefore, AgPt@CaCO3-FA permits synergistic CO gas, catalytic therapy and immunotherapy, effectively eradicating orthotopic breast tumors and preventing tumor metastasis and recurrence.

Intelligent micelles for on-demand drug delivery targeting extracellular matrix of pancreatic cancer

As a key pathological feature of pancreatic ductal adenocarcinoma(PDAC), the dense extracellular matrix(ECM) limits the penetration of chemotherapy drugs and is involved in the formation of immunosuppressive microenvironment. Meanwhile, clinical practice has shown that the treatment strategy for ECM should consider its restriction of tumor cell metastasis, and the need for in-depth chemotherapy without destroying ECM is proposed. STAT3 inhibitors have been reported to regulate tumor microenvironment including interrupt the form of ECM. Therefore, we designed and established a micelle system MP@HA with in vivo targeting and responsive drug release function co-loading gemcitabine monophosphate and STAT3 inhibitor silibinin. The hyaluronic acid on the surface of the micelle can bind specifically to the CD44 molecule on the surface of tumor cells and help micelles accumulate at the tumor site. The nitroimidazole used to modify the polymeric skeleton can make the micellar structure collapse in response to hypoxia reduction conditions in the tumor environment, and release silibinin to widely regulate STAT3 molecules in the PDAC microenvironment. The polymer fragment attached with gemcitabine monophosphate can penetrate deep into PDAC tumors due to its small size and positive charge exposed, achieving deep chemotherapy. This research indicates a promising micelle system meeting complicated demands proposed in PDAC treatment to improve antitumor efficacy.

Crucial roles of exosomes secreted from ganglioside GD3/GD2-positive glioma cells in enhancement of the malignant phenotypes and signals of GD3/GD2-negative glioma cells.

Neuroectoderm-derived tumors characteristically express gangliosides such as GD3 and GD2. Many studies have reported that gangliosides GD3/GD2 enhance malignant phenotypes of cancers. Recently, we reported that human gliomas expressing GD3/GD2 exhibited enhanced malignant phenotypes. Here, we investigated the function of GD3/GD2 in glioma cells and GD3/GD2-expressing glioma-derived exosomes. As reported previously, transfectant cells of human glioma U251 MG expressing GD3/GD2 showed enhanced cancer phenotypes compared with GD3/GD2-negative controls. When GD3/GD2-negative cells were treated with exosomes secreted from GD3/GD2-positive cells, clearly increased malignant properties were observed. Furthermore, increased phosphorylation of signaling molecules was detected after 5-15 min of exosome treatment, ie, higher tyrosine phosphorylation of platelet-derived growth factor receptor, focal adhesion kinase, and paxillin was found in treated cells than in controls. Phosphorylation of extracellular signal-regulated kinase-1/2 was also enhanced. Consequently, it is suggested that exosomes secreted from GD3/GD2-positive gliomas play important roles in enhancement of the malignant properties of glioma cells, leading to total aggravation of heterogenous cancer tissues, and also in the regulation of tumor microenvironments.

RNF43 in cancer: Molecular understanding and clinical significance in immunotherapy.

Identifying biomarkers to predict immune checkpoint inhibitor (ICI) efficacy is warranted. Considering that somatic mutation-derived neoantigens induce strong immune responses, patients with a high tumor mutational burden reportedly tend to respond to ICIs. Therefore, the original function of neoantigenic mutations and their impact on the tumor microenvironment (TME) require attention. RNF43 is a type of RING E3 ubiquitin ligase, and long-term survivors in most cancers had conserved patterns of mutations of RNF43. Also, high microsatellite instability patients had a higher RNF43 mutation rate compared with microsatellite stability tumor patients, who were more sensitive to ICI treatment. Therefore, RNF43 has become a promising biomarker of immunotherapy in a wide range of cancers. This review focuses on the up-to-date knowledge of RNF43 mutation in cancer. We summarize the cancer hallmarks involving activities regulated by RNF43 and highlight its extremely sophisticated regulation of WNT signaling and tumor microenvironment. The key genes interacting with RNF43 have also been summarized and discussed. Additionally, we highlight and propose new strategies of targeting RNF43 and RNF43-based combinations with established immunotherapy and combination therapy. These efforts may provide new perspectives for RNF43-based target therapy in cancer.

P53-associated lncRNAs regulate immune functions and RNA-modifiers in gastric cancer

TP53, a guardian of the genome, suppresses or enhances tumors through various regulatory pathways. However, the role of p53-related long non-coding RNAs (lncRNAs) in immune regulation of tumor microenvironment and prognosis of gastric cancer (GC) is so far unelucidated. We analyzed the role of TP53-associated lncRNAs (obtained from the TP53LNC-DB database) in immune regulation, immune cell infiltration and RNA modification in gastric cancer. Firstly, using multivariate COX regression analysis, we identified eight lncRNAs related to the prognosis of GC. Furthermore, based on the expression of the lncRNA signature and risk score, the GC patients were divided into high-risk and low-risk groups. We found that M2-macrophages have significantly higher infiltration in the high-risk group. Similarly, significant differences in immune function (APC_co_stimulation, CCR, and checkpoint) and m6A modification (FTO, ZC3H13, YTHDC1, and RBM15), and m5C modification (NOP2 and TET1) between both groups were also observed. These signature lncRNAs were also positively associated with oxidative stress-related genes (MPO, MAPK14, HMOX1, and APP). Additionally, we found that high expression of GAS5 and low expression of MALAT1 in Helicobacter pylori (H-pylori) positive GC patients. Finally, GC patients in the low-risk group showed higher resistance to immunotherapy while patients in the high-risk group were more sensitive to various chemotherapy drugs. Based on these findings, we conclude that p53-associated lncRNAs signature could potentially predict the immune status and overall survival, and may also be used for risk management and planning immunotherapy for gastric cancer patients.

Perovskite-structured ultrasensitive CaMnO3 nanoenzyme enables highly efficient ultrasound-amplified and catalysis-involved synergistic tumor therapy

Catalytic nanoenzyme-mediated therapy with reactive oxygen species generation feature and tumor microenvironment regulation characteristic has demonstrated high therapeutic efficacy in oncological field, whereas its low enzyme-mimicking reaction efficacy typically results in dissatisfied therapeutic effect and outcome. Herein, an ultrasensitive CaMnO3 (CMO) nanoenzyme has been rationally designed and engineered for enzyodynamic-calcium overload synergistic tumor therapy. CMO nanoenzyme with oxidase (OXD)-, peroxidase (POD)- and glutathione peroxidase (GPx)-mimic activities is responsible for the generation of reactive oxygen species, the consumption of intra-tumor glutathione and mitochondrial damage. For the evaluation of OXD and POD-mimicking activities, CMO with ultra low concentration (1 μg ml−1) can rapidly catalyze the color reaction of 3,3′,5,5′-tetramethylbenzidine (TMB) hydrochloride and reach the reaction termination in a very short time (1 s). Moreover, the release and overload of Ca2+ strengthen the tumor cell death. Exogenous ultrasound stimulation further amplifies the enzyodynamic-Ca2+ overload synergistic tumor-therapeutic efficacy. In vitro and in vivo results affirm the transcendent antineoplastic outcomes of CMO. Meanwhile, the existence of Mn2+ endows nanoenzyme with T1-weighted MR imaging capacity. This work provides new strategies for efficient enzyme-mimicking activity and tumor synergistic treatment based on new perspectives on the engineering of multifunctional therapeutic nanomedicine.

Regulation of Tumor Microenvironment Under Malignant Conditions: Application of nMOFs in Sonodynamic Therapy

Regulation of Tumor Microenvironment Under Malignant Conditions: Application of nMOFs in Sonodynamic Therapy