bims-flamet 2023-11-19 papers

bims-flamet

Biomed News

on Cytokines and immunometabolism in metastasis

Issue of 2023–11–19
27 papers selected by
Peio Azcoaga, Biodonostia HRI

Macrophage metabolism, phenotype, function, and therapy in hepatocellular carcinoma (HCC).
Histone lactylation regulates cancer progression by reshaping the tumor microenvironment.
Chimeric antigen receptor-based immunotherapy in breast cancer: Recent progress in China.
Crosstalk and plasticity driving between cancer-associated fibroblasts and tumor microenvironment: significance of breast cancer metastasis.
Advances in promoting chimeric antigen receptor T cell trafficking and infiltration of solid tumors.
Molecular interaction of metastasis suppressor genes and tumor microenvironment in breast cancer.
Biological effects of IL-21 on immune cells and its potential for cancer treatment.
Biomimetic inducer enabled dual ferroptosis of tumor and M2-type macrophages for enhanced tumor immunotherapy.
Breaking the feed forward inflammatory cytokine loop in the tumor microenvironment of PDGFB-driven glioblastomas.
NMDAR antagonists suppress tumor progression by regulating tumor-associated macrophages.
The tautomerase activity of tumor exosomal MIF promotes pancreatic cancer progression by modulating MDSC differentiation.
Implications of single-cell immune landscape of tumor microenvironment for the colorectal cancer diagnostics and therapy.
Breast Cancer Macrophage Heterogeneity and Self-renewal are Determined by Spatial Localization.
miR-124 delivered by BM-MSCs-derived exosomes targets MCT1 of tumor-infiltrating Treg cells and improves ovarian cancer immunotherapy.
STING in tumors: a focus on non-innate immune pathways.
The Role of Macrophages in Sarcoma Tumor Microenvironment and Treatment.
Lipocalin-2: A Nurturer of Tumor Progression and a Novel Candidate for Targeted Cancer Therapy.
EMT-induced immune evasion: connecting the dots from mechanisms to therapy.
Cucurbitacin I Reverses Tumor-Associated Macrophage Polarization to Affect Cancer Cell Metastasis.
Systemic infusion of TLR3-ligand and IFN-α in patients with breast cancer reprograms local tumor microenvironments for selective CTL influx.
Multidimensional progressive single-cell sequencing reveals cell microenvironment composition and cancer heterogeneity in lung cancer.
Tumor Microenvironment Sequential Drug/Gene Delivery Nanosystem for Realizing Multistage Boosting of Cancer-Immunity Cycle on Cancer Immunotherapy.
Nanoengineered Macrophages Armed with TLR7/8 Agonist Enhance Remodeling of Immunosuppressive Tumor Microenvironment.
The role of radiotherapy in tumor immunity and the potential of PET/CT in detecting the expression of PD-1/PD-L1.
Application of single-cell sequencing to the research of tumor microenvironment.
Role of Tumor Microenvironment in Pituitary Neuroendocrine Tumors: New Approaches in Classification, Diagnosis and Therapy.
From Race to Racism and Disparities to Equity: An Actionable Biopsychosocial Approach to Breast Cancer Outcomes.

J Transl Med. 2023 Nov 15. 21(1): 815

Macrophage metabolism, phenotype, function, and therapy in hepatocellular carcinoma (HCC).

Jingquan Huang, Qiulin Wu, David A Geller, Yihe Yan.

  The pivotal role of the tumor microenvironment (TME) in the initiation and advancement of hepatocellular carcinoma (HCC) is widely acknowledged, as it fosters the proliferation and metastasis of HCC cells. Within the intricate TME of HCC, tumor-associated macrophages (TAMs) represent a significant constituent of non-malignant cells. TAMs engage in direct communication with cancer cells in HCC, while also exerting influence on other immune cells to adopt a tumor-supportive phenotype that facilitates tumor progression. Among the multifaceted mechanisms at play, the metabolic reprogramming of both tumor cells and macrophages leads to phenotypic alterations and functional modifications in macrophages. This comprehensive review elucidates the intricate interplay between cellular metabolism and macrophage phenotype/polarization, while also providing an overview of the associated signaling molecules and potential therapeutic strategies for HCC.

Keywords:  Function; Hepatocellular carcinoma; Macrophage; Metabolism; Phenotype; Tumor microenvironment

DOI:  https://doi.org/10.1186/s12967-023-04716-0
Front Immunol. 2023 ;14 1284344

Histone lactylation regulates cancer progression by reshaping the tumor microenvironment.

Junxing Qu, Peizhi Li, Zhiheng Sun.

  As a major product of glycolysis and a vital signaling molecule, many studies have reported the key role of lactate in tumor progression and cell fate determination. Lactylation is a newly discovered post-translational modification induced by lactate. On the one hand, lactylation introduced a new era of lactate metabolism in the tumor microenvironment (TME), and on the other hand, it provided a key breakthrough point for elucidation of the interaction between tumor metabolic reprogramming and epigenetic modification. Studies have shown that the lactylation of tumor cells, tumor stem cells and tumor-infiltrating immune cells in TME can participate in the development of cancer through downstream transcriptional regulation, and is a potential and promising tumor treatment target. This review summarized the discovery and effects of lactylation, as well as recent research on histone lactylation regulating cancer progression through reshaping TME. We also focused on new strategies to enhance anti-tumor effects via targeting lactylation. Finally, we discussed the limitations of existing studies and proposed new perspectives for future research in order to further explore lactylation targets. It may provide a new way and direction to improve tumor prognosis.

Keywords:  cancer therapy; epigenetic modification; immune cells; lactylation; tumor microenvironment

DOI:  https://doi.org/10.3389/fimmu.2023.1284344
Cancer. 2023 Nov 11.

Chimeric antigen receptor-based immunotherapy in breast cancer: Recent progress in China.

Tianze Yu, Yuexin Lu, Jianwen Fang, Xiaocong Jiang, Yue Lu, Jingyan Zheng, Xi Shang, Haixing Shen, Peifen Fu.

  Breast cancer (BC) is the fourth most prevalent cancer in China. Despite conventional treatment strategies, BC patients often have poor therapeutic outcomes, leading to significant global cancer mortality rates. Chimeric antigen receptor (CAR)-based immunotherapy is a promising and innovative approach for cancer treatment that redirects immune cells to attack tumor cells expressing selected tumor antigens (TAs). T cells, natural killer (NK) cells, and macrophages, key components of the immune system, are used in CAR-based immunotherapies. Although remarkable progress has been made with CAR-T cells in hematologic malignancies, the application of CAR-based immunotherapy to BC has lagged. This is partly due to obstacles such as tumor heterogeneity, which is further associated with the TA and BC subtypes, and the immunosuppressive tumor microenvironment (TME). Several combinatorial approaches, including the use of immune checkpoint inhibitors, oncolytic viruses, and antitumor drugs, have been proposed to overcome these obstacles in BC treatment. Furthermore, several CAR-based immunotherapies for BC have been translated into clinical trials. This review provides an overview of the recent progress in CAR-based immunotherapy for BC treatment, including targeting of TAs, consideration of BC subtypes, assessment of the TME, and exploration of combinatorial therapies. The authors focused on preclinical studies and clinical trials of CAR-T cells, CAR-NK cells, and CAR-macrophages especially conducted in China, followed by an internal comparison and discussion of current limits. In conclusion, this review elucidates China's contribution to CAR-based immunotherapies for BC and provides inspiration for further research. PLAIN LANGUAGE SUMMARY: Despite conventional treatment strategies, breast cancer (BC) patients in China often have poor therapeutic outcomes. Chimeric antigen receptor (CAR)-based immunotherapy, a promising approach, can redirect immune cells to kill tumor cells expressing selected tumor antigens (TAs). However, obstacles such as TA selection, BC subtypes, and immunosuppressive tumor microenvironment still exist. Therefore, various combinatorial approaches have been proposed. This article elucidates several Chinese CAR-based preclinical and clinical studies in BC treatment with comparisons of foreign research, and CAR-immune cells are analyzed, providing inspiration for further research.

Keywords:  T cells; breast cancer; chimeric antigen receptor; immunotherapy; macrophages; natural killer cells

DOI:  https://doi.org/10.1002/cncr.35096
J Transl Med. 2023 Nov 17. 21(1): 827

Crosstalk and plasticity driving between cancer-associated fibroblasts and tumor microenvironment: significance of breast cancer metastasis.

Wenfeng Zhang, Jia Wang, Cun Liu, Ye Li, Changgang Sun, Jibiao Wu, Qibiao Wu.

  Cancer-associated fibroblasts (CAFs) are the most abundant stromal cell population in breast tumors. A functionally diverse population of CAFs increases the dynamic complexity of the tumor microenvironment (TME). The intertwined network of the TME facilitates the interaction between activated CAFs and breast cancer cells, which can lead to the proliferation and invasion of breast cells. Considering the special transmission function of CAFs, the aim of this review is to summarize and highlight the crosstalk between CAFs and breast cancer cells in the TME as well as the relationship between CAFs and extracellular matrix (ECM), soluble cytokines, and other stromal cells in the metastatic state. The crosstalk between cancer-associated fibroblasts and tumor microenvironment also provides a plastic therapeutic target for breast cancer metastasis. In the course of the study, the inhibitory effects of different natural compounds on targeting CAFs and the advantages of different drug combinations were summarized. CAFs are also widely used in the diagnosis and treatment of breast cancer. The cumulative research on this phenomenon supports the establishment of a targeted immune microenvironment as a possible breakthrough in the prevention of invasive metastasis of breast cancer.

Keywords:  Breast cancer; Cancer-associated fibroblasts; Metastasis; Tumor microenvironment

DOI:  https://doi.org/10.1186/s12967-023-04714-2
Curr Opin Biotechnol. 2023 Nov 15. pii: S0958-1669(23)00130-1. [Epub ahead of print]84 103020

Advances in promoting chimeric antigen receptor T cell trafficking and infiltration of solid tumors.

Mihe Hong, Sohan Talluri, Yvonne Y Chen.

T cells engineered to express chimeric antigen receptors (CARs) have demonstrated robust response rates in treating hematological malignancies. However, solid tumors present multiple challenges that hinder the antitumor efficacy of CAR-T cells, including antigen heterogeneity, off-tumor and systemic toxicities, and the immunosuppressive milieu of the tumor microenvironment (TME). Notably, the TME of solid tumors is characterized by chemokine dysregulation and a dense architecture consisting of tumor stroma, extracellular matrix, and aberrant vasculature that impede migration of CAR-T cells to the tumor site as well as infiltration into the solid-tumor mass. In this review, we highlight recent advances to improve CAR-T-cell trafficking to and infiltration of solid tumors to promote effective antigen recognition by CAR-T cells.

DOI: https://doi.org/10.1016/j.copbio.2023.103020
Explor Target Antitumor Ther. 2023 ;4(5): 912-932

Molecular interaction of metastasis suppressor genes and tumor microenvironment in breast cancer.

Sathammai Sathappa Supuramanian, Sid Dsa, Sitaram Harihar.

  Breast cancer (BC) is a leading cause of cancer-related deaths in women worldwide where the process of metastasis is a major contributor to the mortality associated with this disease. Metastasis suppressor genes are a group of genes that play a crucial role in preventing or inhibiting the spread of cancer cells. They suppress the metastasis process by inhibiting colonization and by inducing dormancy. These genes function by regulating various cellular processes in the tumor microenvironment (TME), such as cell adhesion, invasion, migration, and angiogenesis. Dysregulation of metastasis suppressor genes can lead to the acquisition of an invasive and metastatic phenotype and lead to poor prognostic outcomes. The components of the TME generally play a necessary in the metastasis progression of tumor cells. This review has identified and elaborated on the role of a few metastatic suppressors associated with the TME that have been shown to inhibit metastasis in BC by different mechanisms, such as blocking certain cell signaling molecules involved in cancer cell migration, invasion, enhancing immune surveillance of cancer cells, and promoting the formation of a protective extracellular matrix (ECM). Understanding the interaction of metastatic suppressor genes and the components of TME has important implications for the development of novel therapeutic strategies to target the metastatic cascade. Targeting these genes or their downstream signaling pathways offers a promising approach to inhibiting the spread of cancer cells and improves patient outcomes.

Keywords:  Tumor microenvironment; breast cancer; breast cancer metastasis suppressor 1; metastasis suppressor genes

DOI:  https://doi.org/10.37349/etat.2023.00173
Int Immunopharmacol. 2023 Nov 15. pii: S1567-5769(23)01480-7. [Epub ahead of print]126 111154

Biological effects of IL-21 on immune cells and its potential for cancer treatment.

Meichen Ma, Yuanyuan Xie, Jianhua Liu, Lina Wu, Yong Liu, Xiaosong Qin.

  Interleukin-21 (IL-21), a member of the IL-2 cytokine family, is one of the most important effector and messenger molecules in the immune system. Produced by various immune cells, IL-21 has pleiotropic effects on innate and adaptive immune responses via regulation of natural killer, T, and B cells. An anti-tumor role of IL-21 has also been reported in the literature, as it may support cell proliferation or on the contrary induce growth arrest or apoptosis of the tumor cell. Anti-tumor effect of IL-21 enhances when combined with other agents that target tumor cells, immune regulatory circuits, or other immune-enhancing molecules. Therefore, understanding the biology of IL-21 in the tumor microenvironment (TME) and reducing its systemic toxic and side effects is crucial to ensure the maximum benefits of anti-tumor treatment strategies. In this review, we provide a comprehensive overview on the biological functions, roles in tumors, and the recent advances in preclinical and clinical research of IL-21 in tumor immunotherapy.

Keywords:  Cancer; Cytokine; Immunotherapy; Interleukin-21; Tumor microenvironment

DOI:  https://doi.org/10.1016/j.intimp.2023.111154
Biomaterials. 2023 Nov 04. pii: S0142-9612(23)00394-0. [Epub ahead of print]303 122386

Biomimetic inducer enabled dual ferroptosis of tumor and M2-type macrophages for enhanced tumor immunotherapy.

Mingqi Chen, Yucui Shen, Yinying Pu, Bangguo Zhou, Jinhong Bing, Min Ge, Yaxuan Zhu, Shuang Gao, Wencheng Wu, Min Zhou, Jianlin Shi.

  Tumor-associated macrophages (TAMs) are abundant in the tumor microenvironment which promotes the formation of the immunosuppressive tumor microenvironment (ITME) through multiple mechanisms, severely counteracting the therapeutic efficacy of immunotherapy. In this study, a novel biomimetic ferroptosis inducer (D@FMN-M) capable of ITME regulation for enhanced cancer ferroptosis immunotherapy is reported. Upon tumor accumulation of D@FMN-M, the intratumoral mild acidity triggers the biodegradation of Fe-enriched nanocarriers and the concurrent co-releases of dihydroartemisinin (DHA) and Fe3+. The released Fe3+ is reduced to Fe2+ by consuming intratumoral glutathione (GSH), which promotes abundant free radical generation via triggering Fenton and Fe2+-DHA reactions, thus inducing ferroptosis of both cancer cells and M2-type TAMs. Resultantly, the anticancer immune response is strongly activated by the massive tumor-associated antigens released by ferroptositic cancer cells. Also importantly, the ferroptosis-sensitive M2-type TAMs will be either damaged or gradually domesticated to ferroptosis-resistant M1 TAMs under the ferroptosis stress, favoring the normalization of ITME and finally amplifying cancer ferroptosis immunotherapeutic efficacy. This work provides a novel strategy for ferroptosis immunotherapy of solid tumors featuring TAMs infiltration and immunosuppression by inducing dual ferroptosis of tumor cells and M2-type TAMs.

Keywords:  Ferroptosis inducer; Immunosuppressive tumor microenvironment; M2-type macrophages; Tumor therapy

DOI:  https://doi.org/10.1016/j.biomaterials.2023.122386
J Clin Invest. 2023 Nov 15. pii: e175127. [Epub ahead of print]133(22):

Breaking the feed forward inflammatory cytokine loop in the tumor microenvironment of PDGFB-driven glioblastomas.

C Ryan Miller, Anita B Hjelmeland.

Glioblastoma (GBM) tumor-associated macrophages (TAMs) provide a major immune cell population contributing to growth and immunosuppression via the production of proinflammatory factors, including IL-1. In this issue of the JCI, Chen, Giotti, and colleagues investigated loss of ll1b in the immune tumor microenvironment (TME) in GBM models driven by PDGFB expression and Nf1 knockdown. Survival was only improved in PDGFB-driven GBM models, suggesting that tumor cell genotype influenced the immune TME. IL-1β in the TME increased PDGFB-driven GBM growth by increasing tumor-derived NF-κB, expression of monocyte chemoattractants, and increased infiltration of bone marrow-derived myeloid cells (BMDMs). In contrast, no requirement for IL-1β was evident in Nf1-silenced tumors due to high basal levels of NF-κB and monocyte chemoattractants and increased infiltration of BMDM and TAMs. Notably, treatment of mice bearing PDGFB-driven GBM with anti-IL-1β or an IL1R1 antagonist extended survival. These findings suggest that effective clinical immunotherapy may require differential targeting strategies.

DOI: https://doi.org/10.1172/JCI175127
Proc Natl Acad Sci U S A. 2023 Nov 21. 120(47): e2302126120

NMDAR antagonists suppress tumor progression by regulating tumor-associated macrophages.

Dongchen Yuan, Jing Hu, Xiaoman Ju, Eva Maria Putz, Simin Zheng, Stephane Koda, Guowei Sun, Xiaoran Deng, Zhipeng Xu, Wei Nie, Yang Zhao, Xianyang Li, William C Dougall, Simin Shao, Yan Chen, Renxian Tang, Kuiyang Zheng, Juming Yan.

  Neurotransmitter receptors are increasingly recognized to play important roles in anti-tumor immunity. The expression of the ion channel N-methyl-D-aspartate receptor (NMDAR) on macrophages was reported, but the role of NMDAR on macrophages in the tumor microenvironment (TME) remains unknown. Here, we show that the activation of NMDAR triggered calcium influx and reactive oxygen species production, which fueled immunosuppressive activities in tumor-associated macrophages (TAMs) in the hepatocellular sarcoma and fibrosarcoma tumor settings. NMDAR antagonists, MK-801, memantine, and magnesium, effectively suppressed these processes in TAMs. Single-cell RNA sequencing analysis revealed that blocking NMDAR functionally and metabolically altered TAM phenotypes, such that they could better promote T cell- and Natural killer (NK) cell-mediated anti-tumor immunity. Treatment with NMDAR antagonists in combination with anti-PD-1 antibody led to the elimination of the majority of established preclinical liver tumors. Thus, our study uncovered an unknown role for NMDAR in regulating macrophages in the TME of hepatocellular sarcoma and provided a rationale for targeting NMDAR for tumor immunotherapy.

Keywords:  NMDA receptor; ROS; macrophages; tumor; tumor microenvironment

DOI:  https://doi.org/10.1073/pnas.2302126120
Cancer Immunol Res. 2023 Nov 11.

The tautomerase activity of tumor exosomal MIF promotes pancreatic cancer progression by modulating MDSC differentiation.

Xuebing Jia, Jianbei Xi, Binle Tian, Yuanyuan Zhang, Zhilong Wang, Fan Wang, Zheng Li, Jiang Long, JianFei Wang, Guo-Huang Fan, Qi Li.

Pancreatic cancer is a deadly disease that is largely resistant to immunotherapy, in part because of the accumulation of immunosuppressive cells in the tumor microenvironment (TME). Much evidence suggests that tumor-derived exosomes contribute to the immunosuppressive activity mediated by myeloid-derived suppressor cells (MDSCs) within the pancreatic cancer TME. However, the underlying mechanisms remain elusive. Herein, we report that macrophage migration inhibitory factor (MIF) in tumor-derived exosomes has a key role in inducing MDSC formation in pancreatic cancer. We identified MIF in both human and murine pancreatic cancer-derived exosomes. Upon specific shRNA-mediated knockdown of MIF, the ability of pancreatic cancer-derived exosomes to promote MDSC differentiation was abrogated. This phenotype was rescued by re-expression of the wildtype form of MIF rather than a tautomerase-null mutant or a thiol-protein oxidoreductase-null mutant, indicating that both MIF enzyme activity sites play a role in exosome-induced MDSC formation in pancreatic cancer. RNA sequencing data indicated that MIF tautomerase regulated the expression of genes required for MDSC differentiation, recruitment, and activation. We therefore developed a MIF tautomerase inhibitor, IPG1576. The inhibitor effectively inhibited exosome-induced MDSC differentiation in vitro and reduced tumor growth in an orthotopic pancreatic cancer model, which was associated with decreased numbers of MDSCs and increased infiltration of CD8+ T cells in the TME. Collectively, our findings highlight a pivotal role for MIF in exosome-induced MDSC differentiation in pancreatic cancer and underscore the potential of MIF tautomerase inhibitors to reverse the immunosuppressive pancreatic cancer microenvironment, thereby augmenting anticancer immune responses.

DOI: https://doi.org/10.1158/2326-6066.CIR-23-0205
Med Oncol. 2023 Nov 11. 40(12): 352

Implications of single-cell immune landscape of tumor microenvironment for the colorectal cancer diagnostics and therapy.

Ahmad Alzamami.

  Colorectal cancer (CRC) originates from the polyps lining the colon and is among the most common types of cancer. With the increasing popularity of single-cell sequencing technologies, researchers have been able to better understand the immune landscape of colorectal cancer, by analyzing their expression and interactions in detail with the tumor microenvironment (TME) at single-cell level. Since the tumor-immune cell interactions play a critical part in the advancement as well as treatment response in colorectal cancer, the release of inhibitory factors such as T cells are important for recognizing and destroying cancer cells. Such information is vital to identify immunotherapeutic targets for cure and monitoring response to treatments. Therefore, a comprehensive single-cell studies-based overview of key immunogenic agents regulating the TME of CRC is provided in this review. Tumor-associated macrophages can promote tumor growth and resistance to treatment by releasing factors that inhibit the function of other immune cells. Additionally, colorectal cancer cells can express programmed cell death protein 1 and its ligand, which can also inhibit T-cell function. Researchers have found that certain types of immune cells, prominently T cells, natural killer, and dendritic cells, can have a positive impact on the prognosis of colorectal cancer patients. Treatments like immune checkpoint inhibitors and CAR-T therapies that help to release the inhibitory signals from the cancer cells allow the immune cells to function more effectively.

Keywords:  B cells; Colorectal cancer; Macrophages; NK cells; Single-cell RNA-seq; T cells; TME

DOI:  https://doi.org/10.1007/s12032-023-02226-z
bioRxiv. 2023 Oct 27. pii: 2023.10.24.563749. [Epub ahead of print]

Breast Cancer Macrophage Heterogeneity and Self-renewal are Determined by Spatial Localization.

Nir Ben-Chetrit, Xiang Niu, Jesus Sotelo, Ariel D Swett, Vinagolu K Rajasekhar, Maria S Jiao, Caitlin M Stewart, Priya Bhardwaj, Sanjay Kottapalli, Saravanan Ganesan, Pierre-Louis Loyher, Catherine Potenski, Assaf Hannuna, Kristy A Brown, Neil M Iyengar, Dilip D Giri, Scott W Lowe, John H Healey, Frederic Geissmann, Irit Sagi, Johanna A Joyce, Dan A Landau.

Tumor-infiltrating macrophages support critical steps in tumor progression, and their accumulation in the tumor microenvironment (TME) is associated with adverse outcomes and therapeutic resistance across human cancers. In the TME, macrophages adopt diverse phenotypic alterations, giving rise to heterogeneous immune activation states and induction of cell cycle. While the transcriptional profiles of these activation states are well-annotated across human cancers, the underlying signals that regulate macrophage heterogeneity and accumulation remain incompletely understood. Here, we leveraged a novel ex vivo organotypic TME (oTME) model of breast cancer, in vivo murine models, and human samples to map the determinants of functional heterogeneity of TME macrophages. We identified a subset of F4/80 high Sca-1+ self-renewing macrophages maintained by type-I interferon (IFN) signaling and requiring physical contact with cancer-associated fibroblasts. We discovered that the contact-dependent self-renewal of TME macrophages is mediated via Notch4, and its inhibition abrogated tumor growth of breast and ovarian carcinomas in vivo , as well as lung dissemination in a PDX model of triple-negative breast cancer (TNBC). Through spatial multi-omic profiling of protein markers and transcriptomes, we found that the localization of macrophages further dictates functionally distinct but reversible phenotypes, regardless of their ontogeny. Whereas immune-stimulatory macrophages (CD11C+CD86+) populated the tumor epithelial nests, the stroma-associated macrophages (SAMs) were proliferative, immunosuppressive (Sca-1+CD206+PD-L1+), resistant to CSF-1R depletion, and associated with worse patient outcomes. Notably, following cessation of CSF-1R depletion, macrophages rebounded primarily to the SAM phenotype, which was associated with accelerated growth of mammary tumors. Our work reveals the spatial determinants of macrophage heterogeneity in breast cancer and highlights the disruption of macrophage self-renewal as a potential new therapeutic strategy.

DOI: https://doi.org/10.1101/2023.10.24.563749
Neoplasma. 2023 Nov 15. pii: 230711N362. [Epub ahead of print]

miR-124 delivered by BM-MSCs-derived exosomes targets MCT1 of tumor-infiltrating Treg cells and improves ovarian cancer immunotherapy.

Tian Gao, Yong-Qing Lin, Hai-Yan Ye, Wu-Mei Lin.

Metabolic rewiring of tumor cells leads to an enrichment of lactate in the tumor microenvironment (TME). This lactate-rich environment of solid tumors has been reported to support tumor-infiltrating regulatory T (Treg) cells. Therefore, agents that modify lactate metabolism of Treg cells have therapeutic potential. Monocarboxylate transporter 1 (MCT1), which Treg cells predominantly express, plays an essential role in the metabolism of tumor-infiltrating Treg cells. In this study, we show that miR-124 directly targets MCT1 and reduces the lactate uptake, eventually impairing the immune-suppressive capacity of Treg cells. Particularly, exosomal miR-124 derived from bone marrow mesenchymal stromal cells (BM-MSCs) slows tumor growth and increases response to PD-1 blockade therapy. These data indicate a potential treatment strategy for improving immune checkpoint blockade therapy using miR-124-carried BM-MSCs-derived exosomes.

DOI: https://doi.org/10.4149/neo_2023_230711N362
Front Cell Dev Biol. 2023 ;11 1278461

STING in tumors: a focus on non-innate immune pathways.

Jiaying Yang, Mei Yang, Yingtong Wang, Jicheng Sun, Yiran Liu, Ling Zhang, Baofeng Guo.

  Cyclic GMP-AMP synthase (cGAS) and downstream stimulator of interferon genes (STING) are involved in mediating innate immunity by promoting the release of interferon and other inflammatory factors. Mitochondrial DNA (mtDNA) with a double-stranded structure has greater efficiency and sensitivity in being detected by DNA sensors and thus has an important role in the activation of the cGAS-STING pathway. Many previous findings suggest that the cGAS-STING pathway-mediated innate immune regulation is the most important aspect affecting tumor survival, not only in its anti-tumor role but also in shaping the immunosuppressive tumor microenvironment (TME) through a variety of pathways. However, recent studies have shown that STING regulation of non-immune pathways is equally profound and also involved in tumor cell progression. In this paper, we will focus on the non-innate immune system pathways, in which the cGAS-STING pathway also plays an important role in cancer.

Keywords:  PD-L1; TME; cGAS-STING; extracellular vesicles; mtDNA

DOI:  https://doi.org/10.3389/fcell.2023.1278461
Cancers (Basel). 2023 Nov 05. pii: 5294. [Epub ahead of print]15(21):

The Role of Macrophages in Sarcoma Tumor Microenvironment and Treatment.

Agnieszka E Zając, Anna M Czarnecka, Piotr Rutkowski.

  Sarcomas are a heterogeneous group of malignant mesenchymal tumors, including soft tissue and bone sarcomas. Macrophages in the tumor microenvironment, involved in immunosuppression and leading to tumor development, are called tumor-associated macrophages (TAMs). TAMs are very important in modulating the microenvironment of sarcomas by expressing specific markers and secreting factors that influence immune and tumor cells. They are involved in many signaling pathways, such as p-STAT3/p-Erk1/2, PI3K/Akt, JAK/MAPK, and JAK/STAT3. TAMs also significantly impact the clinical outcomes of patients suffering from sarcomas and are mainly related to poor overall survival rates among bone and soft tissue sarcomas, for example, chondrosarcoma, osteosarcoma, liposarcoma, synovial sarcoma, and undifferentiated pleomorphic sarcoma. This review summarizes the current knowledge on TAMs in sarcomas, focusing on specific markers on sarcoma cells, cell-cell interactions, and the possibly involved molecular pathways. Furthermore, we discuss the clinical significance of macrophages in sarcomas as a potential target for new therapies, presenting clinical relevance, possible new treatment options, and ongoing clinical trials using TAMs in sarcoma treatment.

Keywords:  bone sarcomas; macrophages; soft tissue sarcomas; tumor immunology; tumor-associated macrophages

DOI:  https://doi.org/10.3390/cancers15215294
Cancers (Basel). 2023 Oct 26. pii: 5159. [Epub ahead of print]15(21):

Lipocalin-2: A Nurturer of Tumor Progression and a Novel Candidate for Targeted Cancer Therapy.

Maida Živalj, Jo A Van Ginderachter, Benoit Stijlemans.

  Within the tumor microenvironment (TME) exists a complex signaling network between cancer cells and stromal cells, which determines the fate of tumor progression. Hence, interfering with this signaling network forms the basis for cancer therapy. Yet, many types of cancer, in particular, solid tumors, are refractory to the currently used treatments, so there is an urgent need for novel molecular targets that could improve current anti-cancer therapeutic strategies. Lipocalin-2 (Lcn-2), a secreted siderophore-binding glycoprotein that regulates iron homeostasis, is highly upregulated in various cancer types. Due to its pleiotropic role in the crosstalk between cancer cells and stromal cells, favoring tumor progression, it could be considered as a novel biomarker for prognostic and therapeutic purposes. However, the exact signaling route by which Lcn-2 promotes tumorigenesis remains unknown, and Lcn-2-targeting moieties are largely uninvestigated. This review will (i) provide an overview on the role of Lcn-2 in orchestrating the TME at the level of iron homeostasis, macrophage polarization, extracellular matrix remodeling, and cell migration and survival, and (ii) discuss the potential of Lcn-2 as a promising novel drug target that should be pursued in future translational research.

Keywords:  cancer; cell death; iron transport; lipocalin-2; tumor-associated macrophages

DOI:  https://doi.org/10.3390/cancers15215159
Clin Exp Med. 2023 Nov 15.

EMT-induced immune evasion: connecting the dots from mechanisms to therapy.

Sikiru O Imodoye, Kamoru A Adedokun.

  Epithelial-mesenchymal transition (EMT) is a dynamic program crucial for organismal development and tissue regeneration. Unfortunately, this program is often hijacked by epithelial tumors to facilitate metastasis. Beyond its role in cancer spread, EMT increases cancer cell survival by activating stem cell programs and bypassing apoptotic programs. Importantly, the capacity of EMT to enforce tumor progression by altering the tumor cell phenotype without triggering immune responses opens the intriguing possibility of a mechanistic link between EMT-driven cancers and immune evasion. Indeed, EMT has been acknowledged as a of driver immune evasion, but the mechanisms are still evolving. Here, we review recent insights into the influence of EMT on tumor immune evasion. Specifically, we focus on the mechanistic roles of EMT in immune escape as the basis that may provide a platform for innovative therapeutic approaches in advanced tumors. We summarize promising therapeutic approaches currently in clinical trials and trending preclinical studies aimed at reinvigorating the tumor microenvironment to create immune-permissive conditions that facilitates immune-mediated tumor clearance. We anticipate that this will assist researchers and pharmaceutical companies in understanding how EMT compromises the immune response, potentially paving the way for effective cancer therapies.

Keywords:  Cytotoxic T lymphocyte; Epithelial–mesenchymal transition; Immune evasion; Immunotherapy; NK cells; Tumor microenvironment

DOI:  https://doi.org/10.1007/s10238-023-01229-4
Int J Mol Sci. 2023 Nov 02. pii: 15920. [Epub ahead of print]24(21):

Cucurbitacin I Reverses Tumor-Associated Macrophage Polarization to Affect Cancer Cell Metastasis.

Xiaocheng Gong, Yunfei Liu, Keying Liang, Zixi Chen, Ke Ding, Li Qiu, Jinfen Wei, Hongli Du.

  The tumor microenvironment plays a critical role in tumor progression and immune regulation. As one of the most important components of the tumor microenvironment, macrophages have become a new therapeutic target for inhibiting tumor progression. Despite the well-documented anticancer activity of cucurbitacin I, its effect on macrophages remains unclear. In this study, we established a coculture system of macrophages and cancer cells under hypoxic conditions to simulate the tumor-promoting environment mediated by M2-like macrophages. We determined whether cucurbitacin I modulates M2-like polarization in macrophages in vitro and conducted RNA sequencing to identify gene expression changes induced by cucurbitacin I in macrophages. The results indicated a remarkable inhibition of the M2-like polarization phenotype in macrophages following treatment with cucurbitacin I, which was accompanied by the significant downregulation of heme oxygenase-1. Moreover, we found that cucurbitacin I-treated macrophages reduced the migration of cancer cells by inhibiting the M2 polarization in vitro. These findings highlight the potential of cucurbitacin I as a therapeutic agent that targets M2-like macrophages to inhibit cancer cell metastasis. Our study provides novel insights into the intricate interplay among macrophage polarization, cucurbitacin I, and heme oxygenase-1, thereby opening new avenues for cancer treatment.

Keywords:  M2 macrophage; cucurbitacin I; heme oxygenase-1 (Hmox1); macrophage polarization

DOI:  https://doi.org/10.3390/ijms242115920
J Immunother Cancer. 2023 Nov;pii: e007381. [Epub ahead of print]11(11):

Systemic infusion of TLR3-ligand and IFN-α in patients with breast cancer reprograms local tumor microenvironments for selective CTL influx.

Shipra Gandhi, Mateusz Opyrchal, Melissa J Grimm, Ronald T Slomba, Kathleen M Kokolus, Agnieszka Witkiewicz, Kristopher Attwood, Adrienne Groman, Lauren Williams, Mary Lynne Tarquini, Paul K Wallace, Kah Teong Soh, Hans Minderman, Orla Maguire, Tracey L O'Connor, Amy P Early, Ellis G Levine, Pawel Kalinski.

   BACKGROUND: Presence of cytotoxic T lymphocytes (CTL) in the tumor microenvironment (TME) predicts the effectiveness of cancer immunotherapies. The ability of toll-like receptor 3 (TLR3) ligands, interferons (IFNs) and COX2 inhibitors to synergistically induce CTL-attracting chemokines (but not regulatory T cell (Treg)-attractants) in the TME, but not in healthy tissues, observed in our preclinical studies, suggested that their systemic application can reprogram local TMEs.
METHODS: Six evaluable patients (33-69 years) with metastatic triple-negative breast cancer received six doses of systemic chemokine-modulating (CKM) regimen composed of TLR3 ligand (rintatolimod; 200 mg; intravenous), IFN-α2b (20 MU/m2; intravenous) and COX2 inhibitor (celecoxib; 2×200 mg; oral) over 2 weeks. The predetermined primary endpoint was the intratumoral change in the expression of CTL marker, CD8α, in the post-CKM versus pre-CKM tumor biopsies. Patients received follow-up pembrolizumab (200 mg, intravenously, every 3 weeks), starting 3-8 days after completion of CKM.
RESULTS: Post-CKM biopsies showed selectively increased CTL markers CD8α (average 10.2-fold, median 5.5-fold, p=0.034) and granzyme B (GZMB; 6.1-fold, median 5.8-fold, p=0.02), but not FOXP3 (Treg marker) relative to HPRT1 expression, resulting in the increases in average CD8α/FOXP3 ratio and GZMB/FOXP3 ratio. CKM increased intratumoral CTL-attractants CCL5 and CXCL10, but not Treg-attractants CCL22 or CXCL12. In contrast, CD8+ T cells and their CXCR3+ subset showed transient decreases in blood. One clinical response (breast tumor autoamputation) and three stable diseases were observed. The patient with clinical response remains disease free, with a follow-up of 46 months as of data cut-off.
CONCLUSIONS: Short-term systemic CKM selectively increases CTL numbers and CTL/Treg ratios in the TME, while transiently decreasing CTL numbers in the blood. Transient effects of CKM suggest that its simultaneous application with checkpoint blockade and other forms of immunotherapy may be needed for optimal outcomes.

Keywords:  Breast Neoplasms; Immunotherapy; T-Lymphocytes; Tumor Microenvironment

DOI:  https://doi.org/10.1136/jitc-2023-007381
Environ Toxicol. 2023 Nov 13.

Multidimensional progressive single-cell sequencing reveals cell microenvironment composition and cancer heterogeneity in lung cancer.

Hua Chen, Anqi Song, Faisal Ul Rehman, Dan Han.

  Despite substantial advances in cancer biology and treatment, the clinical outcomes of patients with lung cancer remain unsatisfactory. The tumor microenvironment (TME) is a potential target. Using single-cell RNA sequencing, we could distinguish eight distinct cell types in the lung cancer microenvironment, demonstrating substantial intratumoral heterogeneity in 19 different lung cancer tumor samples. Through the re-dimensional grouping of cancer-associated fibroblasts (CAFs), myeloid cells, epithelial cells, natural killer (NK) cells, and T cells, the difference in the TME of lung cancer was revealed. We discovered SFTPB, SFN, and KRT8 as possible predictive biomarkers for lung cancer by assessing the gene expression patterns in epithelial cells. Examining cell-to-cell communications showed a robust association between the quantity of matrix CAFs, epithelial cells, and macrophages in the thrombospondin signaling pathway. Additionally, we found that the amyloid precursor protein signaling pathway primarily originated from the matrix, and inflammatory cancer-associated endothelial and fibroblast cells showed a co-expression relationship with myeloid cells and B cells. Through cell-to-cell correlation analysis, we found positive regulation between NK cells, regulatory T cells, GZMB-CD8 T cells, and GZMK-CD8 T cells, which could play a role in developing immune TMEs. These findings support studies on cancer heterogeneity and add to our understanding of lung cancer's cellular microenvironment.

Keywords:  biomarkers; lung cancer; single-cell sequencing; tumor heterogeneity; tumor microenvironment

DOI:  https://doi.org/10.1002/tox.24018
ACS Appl Mater Interfaces. 2023 Nov 14.

Tumor Microenvironment Sequential Drug/Gene Delivery Nanosystem for Realizing Multistage Boosting of Cancer-Immunity Cycle on Cancer Immunotherapy.

Yongjing Cao, Juan Li, Qiangwei Liang, Jiayu Yang, Xiaojie Zhang, Juntao Zhang, Min An, Jiawei Bi, Yanhua Liu.

  The antitumor immune response of cancer immunotherapy is a cascade of cancer-immunity cycles (CIC). The immunosuppression of the tumor microenvironment and low immunogenicity of tumor cells, insufficient T lymphocyte activation, trafficking, and infiltration caused the failure to initiate and run the continuous multistage CIC, leading to unsatisfactory cancer immunotherapy outcomes. A doxorubicin/interleukin-12 plasmid DNA/celecoxib (DOX/pIL-12/CXB) combination strategy was designed by targeting the cascade CIC. Then, an intratumoral CXB-detachable nanosystem, or DOX/PAC/pIL-12 micelleplexes, was developed for sequential drug/gene delivery to facilitate the multistage boosting of CIC on synergistic cancer immunotherapy. The DOX/PAC/pIL-12 micelleplexes could program intratumorally sequential release of CXB to remodulate the tumor microenvironment immunosuppression by suppressing the cyclooxygenase-2/prostaglandin E2 (COX-2/PGE2) pathway. The smaller sizes and surface charge-switched micelleplexes facilitated the codelivery and corelease of DOX and pIL-12 inside 4T1 tumor cells. These micelleplexes exerted a synergistic antitumor immune response using CIC cascade activation and amplification, providing therapeutic antitumor and antimetastasis efficacy. The drug/gene sequential delivery nanosystem provides a complete CIC-boosted combinatory strategy for developing immunotherapy against cancer.

Keywords:  cancer immunotherapy; cancer−immunity cycles; celecoxib; doxorubicin; interleukin-12 plasmid DNA; tumor microenvironment sequential drug/gene delivery nanosystem

DOI:  https://doi.org/10.1021/acsami.3c11394
Small. 2023 Nov 15. e2307694

Nanoengineered Macrophages Armed with TLR7/8 Agonist Enhance Remodeling of Immunosuppressive Tumor Microenvironment.

Yeon Jeong Yoo, Ryounho Eun, Hye Min Park, Suhyeon Kim, Sei Hyun Park, Janghun Heo, Yong Taik Lim.

  Although adoptive cell-based therapy is illuminated as one of the promising approaches in cancer immunotherapy, it shows low antitumor efficacy because transferred cells adapt and alter toward a pro-tumoral phenotype in response to the tumor's immunosuppressive milieu. Herein, nanoengineered macrophages anchored with functional liposome armed with cholesterol-conjugated Toll-like receptor 7/8 agonist (masked TLR7/8a, m7/8a) are generated to overcome the shortcomings of current macrophage-based therapies and enhance the remodeling of the immunosuppressive tumor microenvironment (TME). The liposome-anchored macrophages (LAMΦ-m7/8a), are fabricated by anchoring dibenzocyclooctyne-modified liposome(m7/8a) onto azido-expressing macrophages via a bio-orthogonal click reaction, are continuously invigorated due to the slow internalization of liposome(m7/8a) and sustained activation. LAMΦ-m7/8a secreted ≈3 and 33-fold more IL-6 and TNF-α than conventional M1-MΦ, maintained the M1 phenotype, and phagocytosed tumor cells for up to 48 h in vitro. Both intratumoral and intravenous injections of LAMΦ-m7/8a induced effective antitumor efficacy when treated in combination with doxorubicin-loaded liposomes in 4T1-tumor bearing mice. It not only increases the infiltration of antigen-specific CD8+ T cells secreting granzyme B, IFN-γ, and TNF-α within the TME, but also reduces myeloid-derived suppressor cells. These results suggest that LAMΦ-m7/8a may provide a suitable alternative to next-generation cell-based therapy platform.

Keywords:  cancer therapy; cell-based therapy; click chemistry; immunotherapy; macrophages; tumor microenvironment

DOI:  https://doi.org/10.1002/smll.202307694
Jpn J Radiol. 2023 Nov 13.

The role of radiotherapy in tumor immunity and the potential of PET/CT in detecting the expression of PD-1/PD-L1.

Li-Fang Shen, Zi-Ming Fu, Shui-Hong Zhou.

  Upregulation of PD-1/PD-L1 allows cancer cells to escape from host immune systems by functionally inactivating T-cell immune surveillance. Clinical blockade strategies have resulted in an increased prevalence of patients with late-stage cancers. However, many cancer patients had limited or no response to current immunotherapeutic strategies. Therefore, how to improve the sensitivity of immunotherapy has become the focus of attention of many scholars. Radiotherapy plays a role in the recruitment of T cells in the tumor microenvironment, increases CD4 + and CD8 + T cells, and increases PD-L1 expression, resulting in the synergistically enhanced antitumor effect of irradiation and PD-L1 blockade. Radiotherapy can cause changes in tumor metabolism, especially glucose metabolism. Tumor glycolysis and tumor immune evasion are interdependent, glycolytic activity enhances PD-L1 expression on tumor cells and thus promotes anti-PD-L1 immunotherapy response. Therefore, the mechanism of radiotherapy affecting tumor immunity may be partly through intervention of tumor glucose metabolism. Furthermore, some authors had found that the uptake of 2'-deoxy-2'-[18F]fluoro-D-glucose(18F-FDG) was correlated with PD-1/PD-L1 expression. Positron emission tomography/computed tomography (PET/CT) is a non-invasive detection method for PD-1/PD-L1 expression and has several potential advantages over immunohistochemical (IHC), PET/CT can dynamically reflect the expression of PD-1/PD-L1 inside the tumor and further guide clinical treatment.

Keywords:  18F-FDG; Glycolysis; PD-1/PD-L1 axis; PET/CT; Radiotherapy

DOI:  https://doi.org/10.1007/s11604-023-01507-x
Front Immunol. 2023 ;14 1285540

Application of single-cell sequencing to the research of tumor microenvironment.

Sijie Chen, Zhiqing Zhou, Yu Li, Yuhui Du, Guoan Chen.

  Single-cell sequencing is a technique for detecting and analyzing genomes, transcriptomes, and epigenomes at the single-cell level, which can detect cellular heterogeneity lost in conventional sequencing hybrid samples, and it has revolutionized our understanding of the genetic heterogeneity and complexity of tumor progression. Moreover, the tumor microenvironment (TME) plays a crucial role in the formation, development and response to treatment of tumors. The application of single-cell sequencing has ushered in a new age for the TME analysis, revealing not only the blueprint of the pan-cancer immune microenvironment, but also the heterogeneity and differentiation routes of immune cells, as well as predicting tumor prognosis. Thus, the combination of single-cell sequencing and the TME analysis provides a unique opportunity to unravel the molecular mechanisms underlying tumor development and progression. In this review, we summarize the recent advances in single-cell sequencing and the TME analysis, highlighting their potential applications in cancer research and clinical translation.

Keywords:  clinical applications; immunological therapy; precision medicine; single-cell sequencing; tumor microenvironment

DOI:  https://doi.org/10.3389/fimmu.2023.1285540
Cancers (Basel). 2023 Nov 06. pii: 5301. [Epub ahead of print]15(21):

Role of Tumor Microenvironment in Pituitary Neuroendocrine Tumors: New Approaches in Classification, Diagnosis and Therapy.

Dana Antonia Tapoi, Maria-Linda Popa, Cristiana Tanase, Diana Derewicz, Ancuța-Augustina Gheorghișan-Gălățeanu.

  Adenohypophysal pituitary tumors account for 10-15% of all intracranial tumors, and 25-55% display signs of invasiveness. Nevertheless, oncology still relies on histopathological examination to establish the diagnosis. Considering that the classification of pituitary tumors has changed significantly in recent years, we discuss the definition of aggressive and invasive tumors and the latest molecular criteria used for classifying these entities. The pituitary tumor microenvironment (TME) is essential for neoplastic development and progression. This review aims to reveal the impact of TME characteristics on stratifying these tumors in view of finding appropriate therapeutic approaches. The role of the pituitary tumor microenvironment and its main components, non-tumoral cells and soluble factors, has been addressed. The variable display of different immune cell types, tumor-associated fibroblasts, and folliculostellate cells is discussed in relation to tumor development and aggressiveness. The molecules secreted by both tumoral and non-tumoral cells, such as VEGF, FGF, EGF, IL6, TNFα, and immune checkpoint molecules, contribute to the crosstalk between the tumor and its microenvironment. They could be considered potential biomarkers for diagnosis and the invasiveness of these tumors, together with emerging non-coding RNA molecules. Therefore, assessing this complex network associated with pituitary neuroendocrine tumors could bring a new era in diagnosing and treating this pathology.

Keywords:  PitNET; cytokines; growth factors; immune checkpoints; non-coding RNA; non-tumoral cells; pituitary neuroendocrine tumor; tumor microenvironment

DOI:  https://doi.org/10.3390/cancers15215301
Cancer J. 2023 Nov-Dec 01;29(6):29(6): 316-322

From Race to Racism and Disparities to Equity: An Actionable Biopsychosocial Approach to Breast Cancer Outcomes.

Katherine Reeder-Hayes, Mya L Roberson, Stephanie B Wheeler, Yara Abdou, Melissa A Troester.

PURPOSE: Racial disparities in outcomes of breast cancer in the United States have widened over more than 3 decades, driven by complex biologic and social factors. In this review, we summarize the biological and social narratives that have shaped breast cancer disparities research across different scientific disciplines in the past, explore the underappreciated but crucial ways in which these 2 strands of the breast cancer story are interwoven, and present 5 key strategies for creating transformative interdisciplinary research to achieve equity in breast cancer treatment and outcomes.
DESIGN: We first review the key differences in tumor biology in the United States between patients racialized as Black versus White, including the overrepresentation of triple-negative breast cancer and differences in tumor histologic and molecular features by race for hormone-sensitive disease. We then summarize key social factors at the interpersonal, institutional, and social structural levels that drive inequitable treatment. Next, we explore how biologic and social determinants are interwoven and interactive, including historical and contemporary structural factors that shape the overrepresentation of triple-negative breast cancer among Black Americans, racial differences in tumor microenvironment, and the complex interplay of biologic and social drivers of difference in outcomes of hormone receptor positive disease, including utilization and effectiveness of endocrine therapies and the role of obesity. Finally, we present 5 principles to increase the impact and productivity of breast cancer equity research.
RESULTS: We find that social and biologic drivers of breast cancer disparities are often cyclical and are found at all levels of scientific investigation from cells to society. To break the cycle and effect change, we must acknowledge and measure the role of structural racism in breast cancer outcomes; frame biologic, psychosocial, and access factors as interwoven via mechanisms of cumulative stress, inflammation, and immune modulation; take responsibility for the impact of representativeness (or the lack thereof) in genomic and decision modeling on the ability to accurately predict the outcomes of Black patients; create research that incorporates the perspectives of people of color from inception to implementation; and rigorously evaluate innovations in equitable cancer care delivery and health policies.
CONCLUSIONS: Innovative, cross-disciplinary research across the biologic and social sciences is crucial to understanding and eliminating disparities in breast cancer outcomes.

DOI: https://doi.org/10.1097/PPO.0000000000000677