M2 Tumor-associated Macrophages Research Articles

Enhance Mitochondrial Damage by Nuclear Export Inhibition to Suppress Tumor Growth and Metastasis with Increased Antitumor Properties of Macrophages.

Mitochondria-targeting damage has become a popular therapeutic option for tumor metastasis; however, its efficacy is limited by the adaptive rescue capacity of nuclei. There is an urgent need for a dual mitochondrial and nuclear targeting strategy that can also increase the antitumor capacity of macrophages. In this study, XPO1 inhibitor KPT-330 nanoparticles were combined with mitochondria-targeting lonidamine (TPP-LND) nanoparticles. The combination of nanoparticles with a 1:4 ratio of KPT and TL demonstrated the best synergistic effect in restraining the proliferation and metastasis of 4T1 breast cancer cells. Investigating the mechanisms both in vitro and in vivo, it was found that KPT nanoparticles not only directly impede tumor growth and metastasis by controlling the expression of associated proteins but also indirectly facilitate mitochondrial damage. The two nanoparticles synergistically decreased the expression of cytoprotective factors, such as Mcl-1 and Survivin, causing mitochondrial dysfunction and thus inducing apoptosis. Additionally, it downregulated metastasis-related proteins like HIF-1α, vascular endothelial growth factor (VEGF), and matrix metalloproteinase 2 (MMP-2) and reduced endothelial-to-mesenchymal transition. Significantly, their combination increased the ratio of M1 tumor-associated macrophages (TAMs)/M2 TAMs both in vitro and in vivo and increased the phagocytosis of tumor cells by macrophages, thus suppressing tumor growth and metastasis. In summary, this research revealed that nuclear export inhibition can synergistically enhance the prevention of mitochondrial damage to tumor cells, heightening the antitumor properties of TAMs, thereby providing a viable and safe therapeutic approach for the treatment of tumor metastasis.

E. coli Phagelysate: A Primer to Enhance Nanoparticles and Drug Deliveries in Tumor

The tumor microenvironment (TME), where cancer cells reside, plays a crucial role in cancer progression and metastasis. It maintains an immunosuppressive state in many tumors and regulates the differentiation of precursor monocytes into M1 (anti-tumor)- and M2 (pro-tumor)-polarized macrophages, and greatly reduces anticancer drug and nanoparticle delivery. As a result, the effectiveness of recently developed chemo- and/or nanotechnology-mediated immune and magnetic nanoparticle hyperthermia (mNPH) therapies is inhibited significantly. One of the ways to overcome this limitation is to use E. coli phagelysate as a primer to modify the tumor microenvironment by switching tumor-associated M2 macrophages to anti-tumor M1 macrophages, and initiate the infiltration of tumor-associated macrophages (TAMs). Recently, bacteriophages and phage-induced lysed bacteria (bacterial phagelysates—BPLs) have been shown to be capable of modifying the tumor-associated environment. Phage/BPL-coated proteins tend to elicit strong anti-tumor responses from the innate immune system, prompting phagocytosis and cytokine release. It has also been reported that the microenvironments of bacteriophage- and BPL-treated tumors facilitate the conversion of M2-polarized TAMS to a more M1-polarized (tumoricidal) environment post-phage treatment. This paper demonstrates the feasibility and enhanced efficacy of combining E. coli phagelysate (EcPHL) and mNPH, a promising technology for treating cancers, in a rodent model. Specifically, we illustrate the EcPHL vaccination effect on the TME and mNP distribution in Ehrlich adenocarcinoma tumors by providing the tumor growth dynamics and histology (H&E and Prussian blue) distribution of mNP in tumor and normal tissue.

Melittin derived peptide-drug conjugate, M-DM1, inhibits tumor progression and induces effector cell infiltration in melanoma by targeting M2 tumor-associated macrophages.

Melanoma has the highest mortality rate among all the types of skin cancer. In melanoma, M2-like tumor-associated macrophages (TAMs) are associated with the invasiveness of tumor cells and a poor prognosis. Hence, the depletion or reduction of M2-TAMs is a therapeutic strategy for the inhibition of tumor progression. The aim of this study was to evaluate the therapeutic effects of M-DM1, which is a conjugation of melittin (M), as a carrier for M2-like TAMs, and mertansine (DM1), as a payload to induce apoptosis of TAMs, in a mouse model of melanoma. Melittin and DM1 were conjugated and examined for the characterization of M-DM1 by high-performance liquid chromatography and electrospray ionization mass spectrometry. Synthesized M-DM1 were examined for in vitro cytotoxic effects. For the in vivo study, we engrafted murine B16-F10 into right flank of C57BL/6 female mice and administered an array of treatments (PBS, M, DM1, or M-DM1 (20 nmol/kg)). Subsequently, the tumor growth and survival rates were analyzed, as well as examining the phenotypes of tumor-infiltrating leukocytes and expression profiles. M-DM1 was found to specifically reduce M2-like TAMs in melanoma, which potentially leads to the suppression of tumor growth, migration, and invasion. In addition, we also found that M-DM1 improved the survival rates in a mouse model of melanoma compared to M or DM1 treatment alone. Flow cytometric analysis revealed that M-DM1 enhanced the infiltration of CD8+ cytotoxic T cells and natural killer cells (NK cells) in the tumor microenvironment. Taken together, our findings highlight that M-DM1 is a prospective agent with enhanced anti-tumor effects.

Abstract 5829: Differential expression of PD-L1 and PD-L2 is associated with M2 tumor-associated macrophages and tumor differentiation in non-small cell lung cancer

Abstract Objectives: To improve the treatment strategy of immune-checkpoint inhibitors for non-small cell lung cancer (NSCLC), a comprehensive analysis of programmed death-ligand (PD-L)1 and PD-L2 expression is clinically important. The expression of PD-L1 and PD-L2 on tumor cells (TCs) and tumor-infiltrating immune cells (ICs) was investigated with respect to M2 tumor-associated macrophages (TAMs), which are key components of the tumor microenvironment. Methods: We performed immunohistochemical studies to evaluate the M2 TAM distribution by CD163 staining, PD-L1 expression on TCs and ICs by the Ventana SP263 assay, and PD-L2 expression on TCs and ICs, using the Ventana BenchMark GX system, in 175 patients with resected NSCLC. Results: M2 TAM density revealed high levels of variation among the 175 tumor tissues (mean ± standard deviation (SD), 382.5 ± 381.9 cells per mm2). The percentage of PD-L1-positive TCs and PD-L1-positive ICs varied greatly among the 175 tumor tissues (mean ± SD; 15.6 ± 27.0% and 9.4 ± 10.9%, respectively). In addition, the percentage of PD-L2-positive TCs and PD-L2-positive ICs also ranged widely among the 175 tumor tissues (mean ± SD, 14.6 ± 22.9% and 12.5 ± 18.4%, respectively). M2 TAM density was significantly associated with the expression of PD-L1 on TCs and ICs (P < 0.0001 and P < 0.0001, respectively). M2 TAM density was also significantly associated with the expression of PD-L2 on TCs and ICs (P = 0.0452 and P = 0.0125, respectively). The percentage of PD-L1-positive TCs was significantly correlated with the percentage of PD-L1-positive ICs (r = 0.396; P < 0.0001). In addition, the percentage of PD-L2-positive TCs also was significantly correlated with the percentage of PD-L2-positive ICs (r = 0.488; P < 0.0001). However, there was no correlation between the percentage of PD-L1-positive TCs and the percentage of PD-L2-positive TCs (r = 0.019; P = 0.8049). Meanwhile, tumor differentiation was significantly associated with PD-L1 expression on TCs and ICs (P = 0.0002 and P < 0.0001, respectively). By contrast, tumor differentiation was inversely associated with PD-L2 expression on TCs and ICs (P = 0.0260 and P = 0.0326, respectively). Conclusions: PD-L1 and PD-L2 expression on TCs and ICs was associated with M2 TAMs in NSCLC, although there was no correlation between PD-L1 and PD-L2 expression on TCs. The combined evaluation of PD-L1 and PD-L2 expression could be clinically important in the treatment strategy of immune-checkpoint inhibitors in patients with NSCLC. In particular, the evaluation of PD-L2 expression may be necessary for patients with PD-L1-negative NSCLC. Citation Format: Ryota Sumitomo, Huang Cheng-long, Hiroshi Date. Differential expression of PD-L1 and PD-L2 is associated with M2 tumor-associated macrophages and tumor differentiation in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5829.

Abstract 4639: Single-cell immunoprofiling and spatial analysis of hormone receptor subtypes in HER2+ and HER2low breast tumors using multiplexed immunofluorescence

Abstract Background: Breast cancer is characterized by distinct molecular subtypes based on expression of estrogen and progesterone hormone receptors (ER and PR), and epidermal growth factor receptor 2 (HER2). To investigate presence and location of distinct immune cell populations on single cell level we utilized the multiplexed immunofluorescence (mIF) platform MultiOmyx to investigate the tumor immune microenvironment (TME) in HER2+ breast cancer. We have built on growing data implicating distinct immunophenotypes in the breast cancer TME with breast cancer outcomes by profiling 1) prevalence; 2 location (e.g. intratumoral, stromal); 3) phenotype (e.g. activated, exhausted) of infiltrating immune cells. Methods: We optimized a custom 26-marker MultiOmyx panel interrogating HER2 IF expression, HER2 signaling, and immune markers. This mIF platform leverages serial IF image capture to allow concurrent profiling of all 26 markers on a pathologic section at single cell resolution. We applied the 26-marker panel to a tissue microarray of 208 unique patients with matched tumor/normal tissue cores (1-4 cores/patient; total 333 tumor and 307 normal cores). HER2-positive was defined via ASCO/CAP guidelines; HER2-low was defined as HER2 immunohistochemistry (IHC) 1+/2+ but HER2 in-situ hybridization (ISH) negative. Results: The 208 unique tumors profiled included 88.9% (185/208) HER2-positive and 11.1% (23/208) HER2-low; 62.5% (130/208) hormone receptor (HR) positive and 37.5% (78/208) HR negative. Median follow-up from diagnosis was 143 months. Among HER2-positive patients, 98.9% (n=183/185) received HER2-directed therapy in the (neo)adjuvant or metastatic setting or were diagnosed prior to FDA approval of trastuzumab for early stage disease. In sum, from 1166 regions of interest in 640 total cores, a total of 1,076,700 single cells were profiled via the 26-marker panel. Tumors categorized based on HR and HER2 reflected distinct immunophenotype. Relative to HR+HER2low, HR-HER2low tumors had a significant increase in the density of T cells (CD3) and tumor-associated macrophages (TAMs) (CD68). The increase in T cells was observed for T helper (CD3+CD4+), T regulatory (CD3+CD4+FoxP3+), as well as T cytotoxic cells (CD3+CD8+). Observed increases in pro-tumorigenic M2 TAM density (CD68+CD163+) were observed for both HR negative subtypes when compared to HR+HER2+ and HR+HER2low groups, indicating a negative correlation between M2 TAM infiltration and ER/PR status. HER2low tumors had significantly lower tumor PDL1+ than HER2+ tumors. Additionally, 18 of the 208 patients with equal distribution across the hormone-receptor subtypes underwent whole slide multiplexed analysis to perform a deeper spatial analysis. Conclusions: In a large, clinically annotated cohort of breast cancers distinct immunophenotypes are evident among HR and HER2+ subsets. Citation Format: Anna Juncker-Jensen, David Tallman, Harry Nunns, Heather Lefebvre, Karen Yamamoto, Katharine A. Collier, Mark Vater, Ava Strahan, Ava Willoughby, Olivia Bouchard, Madison Kingsbury, Mathew Cherian, Ashley C. Pariser, Preeti K. Sudheendra, Bhuvaneswari Ramaswamy, Margaret Gatti-Mays, Ainura Kyshtoobayeva, Zaibo Li, Daniel G. Stover. Single-cell immunoprofiling and spatial analysis of hormone receptor subtypes in HER2+ and HER2low breast tumors using multiplexed immunofluorescence. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4639.

Abstract 6427: Selective-HDAC inhibitor relieves the suppressive immune microenvironment in the brain to impede breast cancer brain metastasis

Abstract Brain metastasis (BrM) incidence is rising due to longer survival resulted from better systemic control of cancer, counting for approximately 20% of patients with cancers. Major cancer types, including lung, breast, and skin cancers, have a high rate to develop BrM with a 1-year survival rate of less than 20% for symptomatic patients. The overall response rate for immune checkpoint inhibitors (ICI) is merely 10-30% in patients with neurological symptoms. Developing novel combinatorial therapeutic strategies based on mechanistic understanding is urgently needed to further improve the efficacy of current immunotherapies in BrM patients. We recently found that BrMs in patients frequently have severe MHC-I loss. BrM patients' scRNA-seq data from available datasets show that MHC-I expression level is negatively correlated with HDAC level in breast cancer brain metastasis. On the other hand, HDAC inhibitors (HDACi) are epigenetic modulators which have been indicated to recover MHC-I expression loss that contributes to immune invasion. HDACi has been indicated to enhance ICI efficacy in primary tumors by reprogramming the tumor microenvironment (TME). However, the immunomodulatory effect of HDACi is unclear in the unique brain immune microenvironment (BrIME), which is characterized as immunosuppressive. Here, we report that although the selective-HDACi Entinostat has a relatively poor blood-brain barrier (BBB) penetration compared to pan-HDACi Panobinostat, Entinostat induced a comparable level of histone acetylation in the brain to that of Panobinostat. Furthermore, combinatorial treatment consisting of HDACi Entinostat/Panobinostat and anti-PD1 reduced BrM outgrowth of EO771 mammary tumor cell-induced BrM in synergetic mouse model. We explored the impact of HDACi on cell surface MHC-I expression by flow cytometry. Entinostat restored MHC-I expression levels on both brain-seeking human and murine breast and lung cancer cell lines, indicating a general epigenetic regulation on MHC-I expression by inhibition of HDACs. To dissect the impact of HDACi on the BrIME, immune profiling of BrM was performed by mass cytometry (CyTOF). Notably, Entinostat induced a dramatic increment of a specific antigen-presenting cell (APC) cluster in BrM-bearing BrIME with increased ratio of M1 proinflammatory macrophages: M2 tumor-associated macrophages (TAMs) and decreased Tregs. Our results suggest that Entinostat can upregulate MHC-I for more effective antigen presentation and enhance anti-tumor immunity in BrIME. Citation Format: Shao-Ping Yang, Yimin Duan, Xiangliang Yuan, Lin Zhang, Patrick Zhang, Dihua Yu. Selective-HDAC inhibitor relieves the suppressive immune microenvironment in the brain to impede breast cancer brain metastasis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6427.

PD17-04 THE ROLE OF CYTOREDUCTIVE NEPHRECTOMY WITH IMMUNE CHECKPOINT INHIBITOR THERAPIES IN METASTATIC RENAL CELL CARCINOMA MURINE MODEL

You have accessJournal of UrologyCME1 Apr 2023PD17-04 THE ROLE OF CYTOREDUCTIVE NEPHRECTOMY WITH IMMUNE CHECKPOINT INHIBITOR THERAPIES IN METASTATIC RENAL CELL CARCINOMA MURINE MODEL Jee Soo Park, Myung Eun Lee, Won Sik Jang, Jongchan Kim, Se Mi Park, and Won Sik Ham Jee Soo ParkJee Soo Park More articles by this author , Myung Eun LeeMyung Eun Lee More articles by this author , Won Sik JangWon Sik Jang More articles by this author , Jongchan KimJongchan Kim More articles by this author , Se Mi ParkSe Mi Park More articles by this author , and Won Sik HamWon Sik Ham More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003272.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Since CARMENA trial found non-inferiority of sunitinib alone, the contemporary role of cytoreductive nephrectomy (CN) has been significantly downsized. However, updated CARMENA trial results demonstrated certain subsets with metastatic renal cell carcinoma (mRCC) may still benefit from CN. We tried to assess the role of CN in combination with immune checkpoint inhibitor (ICI) from the perspective tumor immune microenvironment (TIME). METHODS: Low- and high-tumor burden pulmonary metastatic orthotopic murine mRCC models have been developed. Anti-PD-1 and anti-CTLA-4 antibodies were systemically injected through the peritoneum every 3 days. Renca implanted kidney was removed in the CN performed group. For the upfront CN plus ICI group, CN was performed 1 day before the ICI, while CN was performed 5 days after ICI for the deferred CN plus ICI group. The remodeling of the TIME was determined using immunofluorescence analysis. RESULTS: Low- and high-tumor burden murine mRCC models have been successfully developed with statistically significant difference in median survival (p<0.05). In low-tumor burden model (Figure 1A), upfront CN plus ICI group demonstrated significantly better survival outcomes compared to deferred CN plus ICI group. In high-tumor burden model (Figure 1B), similar results were shown as low-tumor burden model, except no significant survival difference between ICI only and CN only group, and between upfront CN plus ICI and deferred CN plus ICI group. Immunofluorescence analysis demonstrated that CN modulate TIME by increasing M1 tumor-associated macrophage (TAM) and at the same time decreasing M2 TAM (Figure 2). CONCLUSIONS: This study is the first animal study to demonstrate the role of CN in combination with ICI. We have shown that the CN has certain role in the immune-oncology (IO) era and was associated with improved survival by the regulation of M1 and M2 TAM. CN also regulated myeloid-derived suppressor cells and regulatory T cells in combination with ICIs although not to be significant in our study. Source of Funding: This work was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute funded by the Ministry of Health & Welfare, Republic of Korea [grant number: HI17C1095], and the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) [grant number: 2019R1A2C1002863 and 2022R1A2C2003831] © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e496 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jee Soo Park More articles by this author Myung Eun Lee More articles by this author Won Sik Jang More articles by this author Jongchan Kim More articles by this author Se Mi Park More articles by this author Won Sik Ham More articles by this author Expand All Advertisement PDF downloadLoading ...

Efficient tumor synergistic chemoimmunotherapy by self-augmented ROS-responsive immunomodulatory polymeric nanodrug

Immunotherapy has emerged as a promising therapeutic strategy for cancer therapy. However, the therapeutic efficacy has been distracted due to poor immunogenicity and immunosuppressive tumor microenvironment. In this study, a self-augmented reactive oxygen species (ROS) responsive nanocarrier with immunogenic inducer paclitaxel (PTX) and indoleamine 2,3-dixoygenase 1 (IDO1) blocker 1-methyl-d, L-tryptophan (1-MT) co-entrapment was developed for tumor rejection. The carrier was composed of poly (ethylene glycol) (PEG) as hydrophilic segments, enzyme cleavable 1-MT ester and ROS-sensitive peroxalate conjugation as hydrophobic blocks. The copolymer could self-assemble into prodrug-based nanoparticles with PTX, realizing a positive feedback loop of ROS-accelerated PTX release and PTX induced ROS generation. Our nanoparticles presented efficient immunogenic cell death (ICD) which provoked antitumor immune responses with high effector T cells infiltration. Meanwhile immunosuppressive tumor microenvironment was simultaneously modulated with reduced regulatory T cells (Tregs) and M2-tumor associated macrophages (M2-TAMs) infiltration mediated by IDO inhibition. The combination of PTX and 1-MT achieved significant primary tumor regression and reduction of lung metastasis in 4T1 tumor bearing mice. Therefore, the above results demonstrated co-delivery of immunogenic inducer and IDO inhibitor using the ROS amplifying nanoplatform with potent potential for tumor chemoimmunotherapy.

Macrophages M2 polarization is involved in lapatinib-mediated chemopreventive effects in the lung cancer

M2 polarized tumor-associated macrophages (TAMs) have a multifunctional role in cancer initiation, progression, metastasis, and contribute to chemotherapeutic resistance. Therefore, identifying M2 polarized TAMs is a potential target for cancer therapeutic intervention. The underlying mechanism that target the TAMs M2 polarized macrophages remains primarily uncharacterized; however, only a few compounds have been identified that inhibit TAMs M2 polarized macrophages. In this research, we investigated that lapatinib could effectively suppress the expression of IL_13-induced M2 polarized macrophages surface markers i.e., CD163 and CD206, and downregulation of M2 genes such as Fizz1, Mrc1, Arg1, IL-10, Ym1, nd CCL2 in vitro. Moreover, lapatinib abrogated the M2 polarized macrophage-mediated cancer cells invasion and migration. Mechanistically, in our study, lapatinib inhibited IL-13 triggered STAT6 phosphorylation. Furthermore, in LLCs tumor model, lapatinib significantly reduced tumorigenesis, followed by the downregulation of percentages of M2 marker CD206+ and CD68+ in the tumor. This downregulation correlates with chemopreventive effect of lapatinib. All taken together, these results demonstrated that lapatinib effectively prevents the macrophage M2 polarization and indicates a potential mechanism for preventing the tumor growth via M2 polarized polarization intervention.

Metabolism-related long non-coding RNA in the stomach cancer associated with 11 AMMLs predictive nomograms for OS in STAD.

Background: The metabolic processes involving amino acids are intimately linked to the onset and progression of cancer. Long non-coding RNAs (LncRNAs) perform an indispensable function in the modulation of metabolic processes as well as the advancement of tumors. Non-etheless, research into the role that amino acid metabolism-related LncRNAs (AMMLs) might play in predicting the prognosis of stomach adenocarcinoma (STAD) has not been done. Therefore, This study sought to design a model for AMMLs to predict STAD-related prognosis and elucidate their immune properties and molecular mechanisms. Methods: The STAD RNA-seq data in the TCGA-STAD dataset were randomized into the training and validation groups in a 1:1 ratio, and models were constructed and validated respectively. In the molecular signature database, This study screened for genes involved in amino acid metabolism. AMMLs were obtained by Pearson's correlation analysis, and predictive risk characteristics were established using least absolute shrinkage and selection operator (LASSO) regression, univariate Cox analysis, and multivariate Cox analysis. Subsequently, the immune and molecular profiles of high- and low-risk patients and the benefit of the drug were examined. Results: Eleven AMMLs (LINC01697, LINC00460, LINC00592, MIR548XHG, LINC02728, RBAKDN, LINCOG, LINC00449, LINC01819, and UBE2R2-AS1) were used to develop a prognostic model. Moreover, high-risk individuals had worse overall survival (OS) than low-risk patients in the validation and comprehensive groups. A high-risk score was associated with cancer metastasis as well as angiogenic pathways and high infiltration of tumor-associated fibroblasts, Treg cells, and M2 macrophages; suppressed immune responses; and a more aggressive phenotype. Conclusion: This study identified a risk signal associated with 11 AMMLs and established predictive nomograms for OS in STAD. These findings will help us personalize treatment for gastric cancer patients.

Resistance mechanisms of immune checkpoint inhibition in lymphoma: Focusing on the tumor microenvironment.

Immune checkpoint inhibitors (ICIs) have revolutionized the therapeutic strategies of multiple types of malignancies including lymphoma. However, efficiency of ICIs varies dramatically among different lymphoma subtypes, and durable response can only be achieved in a minority of patients, thus requiring unveiling the underlying mechanisms of ICI resistance to optimize the individualized regimens and improve the treatment outcomes. Recently, accumulating evidence has identified potential prognostic factors for ICI therapy, including tumor mutation burden and tumor microenvironment (TME). Given the distinction between solid tumors and hematological malignancies in terms of TME, we here review the clinical updates of ICIs for lymphoma, and focus on the underlying mechanisms for resistance induced by TME, which play important roles in lymphoma and remarkably influence its sensitivity to ICIs. Particularly, we highlight the value of multiple cell populations (e.g., tumor infiltrating lymphocytes, M2 tumor-associated macrophages, and myeloid-derived suppressor cells) and metabolites (e.g., indoleamine 2, 3-dioxygenase and adenosine) in the TME as prognostic biomarkers for ICI response, and also underline additional potential targets in immunotherapy, such as EZH2, LAG-3, TIM-3, adenosine, and PI3Kδ/γ.

M2 tumor-associated macrophages resist to oxidative stress through heme oxygenase-1 in the colorectal cancer tumor microenvironment.

M2 tumor-associated macrophages (M2-TAMs) promote cancer cell proliferation and metastasis in the TME. Our study aimed to elucidate the mechanism of increased frequency of M2-TAMs infiltration in the colorectal cancer (CRC)-TME, focusing on the resistance to oxidative stress through nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. In this study, we evaluated the correlation between M2-TAM signature and mRNA expression of antioxidant related genes using public datasets, and the expression level of antioxidants in M2-TAMs by flow cytometry and the prevalence of M2-TAMs expressing antioxidants by immunofluorescence staining using surgically resected specimens of CRC (n = 34). Moreover, we generated M0 and M2 macrophages from peripheral blood monocytes and evaluated their resistance to oxidative stress using the in vitro viability assay. Analysis of GSE33113, GSE39582, and The Cancer Genome Atlas (TCGA) datasets indicated that mRNA expression of HMOX1 (heme oxygenase-1 (HO-1)) was significantly positively correlated with M2-TAM signature (r = 0.5283, r = 0.5826, r = 0.5833, respectively). The expression level of both Nrf2 and HO-1 significantly increased in M2-TAMs compared to M1- and M1/M2-TAMs in the tumor margin, and the number of Nrf2+ or HO-1+M2-TAMs in the tumor stroma significantly increased more than those in the normal mucosa stroma. Finally, generated M2 macrophages expressing HO-1 significantly resisted to oxidative stress induced by H2O2 in comparison with generated M0 macrophages. Taken together, our results suggested that an increased frequency of M2-TAMs infiltration in the CRC-TME is related to Nrf2-HO-1 axis mediated resistance to oxidative stress.

The expression of Rab5 and its effect on invasion, migration and exosome secretion in triple negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and current therapeutic strategies are limited in their effectiveness. The expressions of Rab5 and the M2 tumor-associated macrophage marker CD163 in tissues were detected by Western blot. The migration and invasion of cells were determined using a Transwell assay. The expressions of the exosome markers were evaluated by Western blot. The polarization of human macrophages (THP-1) was determined by incubation of THP-1 cells with conditioned medium or exosomes collected from MDA-MB-231 cells with indicated transfections or by a coculture system of THP-1 and MDA-MB-231 cells. The M1 and M2 macrophage markers were evaluated by qRT-PCR. The expression of Rab5 in TNBC was significantly higher than that in normal breast tissue. Rab5 expressions in triple-negative and luminal A breast cancer were higher than those in other molecular subtypes. Higher CD163 expression was observed in triple-negative breast cancer and in triple-negative and luminal B subtypes. Rab5 knockdown suppressed but Rab5 overexpression promoted the migration and invasion capacity of MDA-MB-231 cells. The levels of CD63 and CD9 in the medium of Rab5 knockdown cells were lower than those in control cells, whereas higher levels of CD63 and CD9 were observed in Rab5 overexpression cells. Rab5 knockdown decreased the excretion but did not alter the diameter of the exosomes. Knockdown of Rab5 facilitated the anti-tumor polarization of macrophages, which was partially reversed by Rab5 overexpression. Therefore, Rab5 is expected to be a potential therapeutic target for triple-negative breast cancer.

Abstract P2-20-05: Personalized tumor vaccine can suppress tumor growth and metastasis in the syngeneic mouse breast cancer model

Abstract Objective Immunotherapy using the tumor-specific antigens (TSAs) is a promising strategy in breast cancer. Studies have suggested that the in vivo exposures to certain tumors can induce adaptive anti-tumor immunity in syngeneic tumor models. In this study, we show the efficacy of the tumor lysate vaccine and peptide-based vaccine against tumor neoantigen in suppressing tumor growth and metastasis in 4T1 syngeneic tumor models. Method We used BALB/c mice and its syngeneic tumor cell lines to evaluate the anti-tumor effect induced by the transient exposure to the tumor cells. For tumor vaccines, we synthesized the tumor lysate vaccine by the freeze-thaw method or synthetic peptide against the selected tumor neoantigens identified by exome sequencing. We systemic and local immune remodeling was investigated by using immunohistochemistry, flow cytometry, and single cell RNA sequencing. Results We observed a significant reduction of tumor growth and metastasis in 4T1 syngeneic tumors when the mice were previously exposed to the same cells (pre-exposure group). This anti-tumor effect induced by the exposures to the tumor was cell line-specific. The 4T1 tumor lysate vaccines administered prior to the tumor cell injection also showed significant inhibitory effect on tumor growth and metastasis. T lymphocytes, isolated from the tumor tissues of the 4T1 pre-exposure mice and lysate vaccine-treated mice, showed higher levels of TNF-ɑ and IFN-ɣ when compared to the control those from the control tumors. The lysate vaccine treatment resulted in a substantial remodeling of tumor microenvironment including reduction of myeloid-derived suppressor cells and M2 tumor-associated macrophages. On the other hand, the numbers of M1 tumor-associated macrophages and effector memory CD8+ T cells were increased by the lysate vaccine. While the peptide vaccine showed no inhibitory effect on the primary tumor growth, it also suppressed spontaneous lung metastasis. Finally, we administered lysate tumor vaccine after the tumor establishment to determine the therapeutic effect. The lysate vaccine significantly suppressed the tumor growth and lung metastasis of the syngeneic 4T1 tumors. Conclusion Tumor lysate vaccine can suppress the tumor growth and metastasis in the 4T1 syngeneic mouse models by inducing substantial remodeling of tumor immune microenvironment. Additionally, tumor lysate vaccine can elicit similar anti-tumor immune response when administered after the establishment of the primary tumor suggesting a potential therapeutic value. Citation Format: Hyeong-Gon Moon, Hye Youn Son, Woo Hang Heo, Mingji Quan, SONGBIN LI, Haritonova Valentina, Hamin Jeong, Wonshik Han, Han-Byoel Lee, YUJEONG HER, Ju Hee Kim. Personalized tumor vaccine can suppress tumor growth and metastasis in the syngeneic mouse breast cancer model [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-20-05.

Differential expression of PDL-1 and tumour-associated macrophages in N0 and N+ penile cancer.

12 Background: Penile squamous cell carcinoma (PSCC) is rare, representing 0.4-0.6% of all male malignancies in the global-north, as compared with 2-10% in the global-south. Overall survival (OS) dramatically decreases with increased lymph node metastases (LNM). Increased prevalence of pro-tumorigenic M2 CD163+ tumour associated macrophages (TAM) is associated with poor PSCC OS, whereas increased prevalence of the generic M1/2 CD68+ TAMs is associated with better PSCC OS. PDL-1 expression has been noted in 40-60% of PSCC primary lesions. However, there is a paucity of evidence on the overall tumour immune microenvironment (TME) within penile LNM disease. This study describes the relationship between PDL-1 expression and TAMs within the TME of the primary tumour and paired LNMs, with the goal of predicting the utility of PD-1 inhibitors in clinical trials in PSCC. Methods: The Ventana Discovery ULTRA platform was used to optimise a 7-marker multiplex immunofluorescence panel on whole FFPE sections of primary and LNM lesions. Multispectral images were captured using a Vectra 3 microscope. Single cell spatial analysis was performed using HALO software, with statistical analysis of data using R 4.2.1. Results: 52 cases with differing LN stages were identified: N0 (N=20); N1/N2 (N=21); N3 (N=11). Increased expression of PDL-1 was noted at the primary lesion invasive margin (IM) of N+, compared with N0 patients. High expression in inguinal LNMs (iLN+) and pelvic LNMs (pLN+) was also observed, with no expression detected in microscopically normal, tumour free LNs (LN-) in the N0 cohort. More CD163+ M2 TAMs were observed at the IM of N+ compared with N0. However, no significant difference was observed between the three LN groups. M1/2 CD68+ TAMs were more prevalent within pLN+ vs iLN+ or LN-. There was no significant difference in M1/2 CD68+ TAMs number at the IM. Conclusions: Our data highlights increased prevalence of M2 CD163+ TAMs within the IM is associated with LNM. Increased presence of CD68+ M1/2 TAMs in pLN+ may represent active inflammation at the leading microscopic edge of metastatic deposits. A significant difference in the expression of PDL-1 between localised and metastatic disease at both primary and LN location is noted. High PDL-1 expression at the IM of the primary lesion is associated with increased LNMs, where PDL-1 expression is significantly higher as compared to LN-. This study supports the rationale for the use of anti-PD-1/PDL-1 therapies in patients with LNM disease.

Anti-PD1 plus oncolytic virus as first-line treatment option for metastatic renal cell carcinomas.

675 Background: Although anti-programmed death (PD)1 and anti-cytotoxic T-cell lymphocyte (CTLA)-4 combination therapy is recommended as one of the first line treatment options for metastatic renal cell carcinoma (mRCC), immune checkpoint inhibitor (ICI) combination therapy leads to the increased immune-mediated adverse events (imAEs). Our group has reported the therapeutic potential of oncolytic virus, JX-594 in metastatic murine RCC model. In this study, we explored the effect of JX-594 plus anti-PD1 in comparison to the combination therapy of anti-PD1 and anti-CTLA-4. Methods: Early-stage and advanced-stage highly metastatic orthotopic murine RCC models developed by our group were used. Anti-PD1 with either JX-594 or anti-CTLA-4 were systemically injected through the peritoneum. Immunofluorescence analysis was performed to demonstrate the remodeling of the tumor immune microenvironment (TIME). Results: Both JX-594 plus anti-PD1 and ICI combination therapy significantly reduced primary tumor and metastatic tumor burden in lung and peritoneum compared to cytoreductive nephrectomy plus anti-PD1. For the early-stage and advanced-stage mRCC models, JX-594 plus anti-PD1 significantly decreased the primary tumor sizes and number of lung tumor nodules compared to ICI combination therapy only in the early-stage mRCC model ( P&lt;0.01), but not in advanced-stage mRCC model ( P=0.07). The therapeutic benefit was significantly increased when JX-594 and anti-PD1 was sequentially injected compared to when JX-594 and anti-PD1 was injected simultaneously ( P&lt;0.05). Notable imAEs were observed in 2/16 (12.5%) in ICI combination group, whereas no notable imAEs in JX-594 plus anti-PD1 group. JX-594 plus anti-PD1 induced changes in TIME of both early- and advanced-stage mRCC model. However, tumor-suppressing TIME was more notable in early-stage mRCC model, which increased tumor-infiltrating CD8+ T cells and tumor-suppressing M1 tumor-associated macrophages (TAM), and decreased tumor-promoting myeloid-derived suppressor cells (MDSCs) and M2 TAM. Conclusions: JX-594 plus anti-PD1 effectively reduced primary tumors and metastatic burdens similar to ICI combination therapy. Furthermore, imAEs significantly decreased in JX-594 plus anti-PD1 group, suggesting the potential benefit of JX-594 plus anti-PD1 for reserving ICI induced toxicities, especially by anti-CTLA-4.

RGS12 represses oral squamous cell carcinoma by driving M1 polarization of tumor-associated macrophages via controlling ciliary MYCBP2/KIF2A signaling

Tumor-associated macrophages (TAMs) play crucial roles in tumor progression and immune responses. However, mechanisms of driving TAMs to antitumor function remain unknown. Here, transcriptome profiling analysis of human oral cancer tissues indicated that regulator of G protein signaling 12 (RGS12) regulates pathologic processes and immune-related pathways. Mice with RGS12 knockout in macrophages displayed decreased M1 TAMs in oral cancer tissues, and extensive proliferation and invasion of oral cancer cells. RGS12 increased the M1 macrophages with features of increased ciliated cell number and cilia length. Mechanistically, RGS12 associates with and activates MYC binding protein 2 (MYCBP2) to degrade the cilia protein kinesin family member 2A (KIF2A) in TAMs. Our results demonstrate that RGS12 is an essential oral cancer biomarker and regulator for immunosuppressive TAMs activation.

Noncoding RNAs Controlling Oxidative Stress in Cancer

Mitochondria in cancer cells tend to overproduce reactive oxygen species (ROS), inducing a vicious cycle between mitochondria, ROS, genomic instability, and cancer development. The first part of this review deals with the role of noncoding RNAs in regulating mitochondrial ROS production and the expression of antioxidants in cancer cells, preventing the increase of ROS in the tumor microenvironment. In addition, cytotoxic T and natural killer cells release high levels of ROS, inducing cell death, while anti-immune regulatory T cells, tumor-associated M2 macrophages, and myeloid-derived suppressor cells, at least at the initial stage of tumor growth, release low levels of ROS supporting tumor growth. Therefore, this review's second part deals with noncoding RNAs' role in regulating the metabolic reprogramming of immune cells about ROS release. Furthermore, the enrichment of noncoding RNAs in microvesicles allows communication between cell types in a tumor and between a tumor and tumor-adjacent tissues. Therefore, the third part illustrates how noncoding RNA-containing microvesicles secreted by mesenchymal stem cells and primary tumor cells may primarily aid the shift of immune cells to a pro-oncogenic phenotype. Conversely, microvesicles released by tumor-adjacent tissues may have the opposite effect. Our review reveals that a specific noncoding RNA may affect oxidative stress by several mechanisms, which may have opposite effects on tumor growth. Furthermore, they may be involved in mechanisms other than regulating oxidative stress, which may level out their effects on oxidative stress and tumor growth. In addition, several noncoding RNAs might share a specific function, making it very unlikely that intervening with only one of these noncoding RNAs will block this particular mechanism. Overall, further validation of the interaction between noncoding RNAs about cancer types and stages of tumor development is warranted.

Reprogramming the tumor microenvironment leverages CD8+ T cell responses to a shared tumor/self antigen in ovarian cancer

Tumor antigen-driven responses to weakly immunogenic self-antigens and neoantigens directly affect treatment efficacy following immunotherapy. Using orthotopically grown SV40T antigen+ ovarian carcinoma in antigen-naive wild-type or TgMISIIR-TAg-Low transgenic mice expressing SV40T antigen as a self-antigen, we investigated the impact of CXCR4-antagonist-armed oncolytic virotherapy on tumor progression and antitumor immunity. Immunostaining and single-cell RNA sequencing analyses of the peritoneal tumor microenvironment of untreated tumors in syngeneic wild-type mice revealed the presence of SV40T antigen-specific CD8+ Tcells, a balanced M1/M2 transcriptomic signature of tumor-associated macrophages, and immunostimulatory cancer-associated fibroblasts. This contrasted with polarized M2 tumor-associated macrophages, immunosuppressive cancer-associated fibroblasts, and poor immune activation in TgMISIIR-TAg-Low mice. Intraperitoneal delivery of CXCR4-antagonist-armed oncolytic vaccinia virus led to nearly complete depletion of cancer-associated fibroblasts, M1 polarization of macrophages, and generation of SV40T antigen-specific CD8+ Tcells in transgenic mice. Cell depletion studies revealed that the therapeutic effect of armed oncolytic virotherapy was dependent primarily on CD8+ cells. These results demonstrate that targeting the interaction between immunosuppressive cancer-associated fibroblasts and macrophages in the tolerogenic tumor microenvironment by CXCR4-A-armed oncolytic virotherapy induces tumor/self-specific CD8+ Tcell responses and consequently increases therapeutic efficacy in an immunocompetent ovarian cancer model.

“Two birds with one stone” strategy for the lung cancer therapy with bioinspired AIE aggregates

Aggregation-induced emission luminogens (AIEgens) have emerged as novel phototherapeutic agents with high photostability and excellent performance to induce photodynamic and/or photothermal effects. In this study, a zwitterion-type NIR AIEgens C41H37N2O3S2 (named BITT) with biomimetic modification was utilized for lung cancer therapy. The tumor-associated macrophage (TAM)-specific peptide (CRV) was engineered into the lung cancer cell-derived exosomes. The CRV-engineered exosome membranes (CRV-EM) were obtained to camouflage the BITT nanoparticles (CEB), which targeted both lung cancer cells and TAMs through homotypic targeting and TAM-specific peptide, respectively. The camouflage with CRV-EM ameliorated the surface function of BITT nanoparticles, which facilitated the cellular uptake in both cell lines and induced significant cell death in the presence of laser irradiations in vitro and in vivo. CEB showed improved circulation lifetime and accumulations in the tumor tissues in vivo, which induced efficient photodynamic and photothermal therapy. In addition, CEB induced the tumor microenvironment remodeling as indicated by the increase of CD8 + and CD4 + T cells, as well as a decrease of M2 TAM and Myeloid-derived suppressor cells (MDSCs). Our work developed a novel style of bioinspired AIE aggregates, which could eliminate both lung cancer cells and TAMs, and remodel the tumor environments to achieve an efficient lung cancer therapy. To the best of our knowledge, we are the first to use this style of bioinspired AIE aggregates for photo-mediated immunotherapy in lung cancer therapy.